McNeil's notes - stats/epi, coagulation cascade, trauma, cancer (gen, uro only), ICU, fluids, anesthesia, Neurology, SCI/nerve injuries Flashcards
A new test is able to identify true positives in 350 patients, true negatives in 1200 patients and false negatives in 150 patients. What is the sensitivity of the test? A. 60% B. 70% C. 80% D. 90%
Answer: 70%
Sen = TP/TP + FN
When the test has 95% sensitivity, this means:
a. 95% of the patient will be positive
b. Patients who are tested positive, 95% of them will have the disease
c. Patients who are tested positive, 5% will have the disease
d. Of the patients who have the condition, the test will detect 95% of them
d. Of the patients who have the condition, the test will detect 95% of them.
sensitivity is the ability of the test to identify correctly those who have the disease (SNOUT-highly sensitive test, a negative result helps rule out disease); specificity is the ability of the test to identify correctly those who do not have the disease (SPIN-a highly specific test, a positive result helps rule in the disease).
A new blood test is available to diagnose pulmonary embolus. The data from a trial of 1000 post operative patients is shown in the 2x2 table below:
PE Present PE Absent
Test Positive 95 100
Test Negative 5 800
1) The sensitivity of the above test is calculated by the equation
a. 800/(100+800)
b. 800/(800+5)
c. 95/(95+5)
d. 95/(95+100)
e. none of the above
c. 95/(95+5)
Sensitivity = true positive (TP)/true positive + false negative
A new blood test is available to diagnose pulmonary embolus. The data from a trial of 1000 post operative patients is shown in the 2x2 table below: PE Present PE Absent Test Positive 95 100 Test Negative 5 800 2) The specificity of the above test is calculated by the equation a. 800/(100+800) b. 800/(800+5) c. 95/(95+5) d. 95/(95+100) e. none of the above
a . 800/(100+800)
Specificity = true neg / (true neg + false positive)
A new blood test is available to diagnose pulmonary embolus. The data from a trial of 1000 post operative patients is shown in the 2x2 table below: PE Present PE Absent Test Positive 95 100 Test Negative 5 800 3) The positive predictive value of the above test is calculated by the equation: a. 800/(100+800) b. 800/(800+5) c. 95/(95+5) d. 95/(95+100) e. none of the above
d. 95/(95+100)
PPV = true positive/(true positive + false positive)
A test that detects the number of people who actrally have the disease measures …
a) specificity
b) sensitivity
c) positive predictive value
d) negative predictive value
Answer given: sensitivity. Disagree however - this sounds more like PPV.
sensitivity – the proportion (%age) of truly diseased people identified as diseased by a screening test
specificity - the proportion (%age) of truly non-diseased prople identified as non-diseased by the screening test
PPV - the proportion of true positives in all positive tests (the number of cases that truly have disease among all those who test positive)
NPV – the proportion of true negatives in all the negative tests
Which of the following is the MOST helpful in establishing a causal relationship between exposure and disease? A. Positive predictive value B. Sensitivity C. Odds ratio D. T-test
Odds ratio = retrospective studies
Risk = prosp[ective studies
Answer: Odds ratio
A world health organization epidemiologist is studying esophageal cancer in females. In Canada, 5,000,000 females over the age of 25 years have been followed from January 1, 1980 to January 1, 2000. Within this population, a group of 1,000,000 women chronically exposed to sulphur dioxide fumes are found to have an increased incidence of developing esophageal cancer as compared to the 4,000,000 that were not chronically exposed. The data is shown below:
Group Esophageal Cancer Incidence (per 1,000,000)
Exposed 100
Not exposed 20
Calculate the relative risk of developing esophageal cancer in those women chronically exposed to sulphur dioxide fumes
a) 100
b) 20
c) 5
d) 0.2
e) none of the above
Answer: 5
Relative Risk = A/ A+B
C/ C+D
RR = 100/1,000,000
80/4,000,000
= 100/1,000,000 20/1,000,000 = 5
A new treatment changes the mortality of acute MI from 26 % in the placebo group to 16 % in the treatment group. The number needed to treat is:
a. 10
b. 100
c. 200
d. 1000
a. 10
ARR = |CER - EER| = |26% - 16%| =10% NNT = 1/ARR = 1/.1 = 10
If β blockers decrease risk of MI by 25% and the mortality of MI is 1% in one year, what is the absolute risk reduction and the number of patients needed to be treated to decrease mortality by one patient:
a. 0.25% - 400 patients.
b. 2.5% - 40 patients.
c. 25% - 4 patients.
d. 1% - 10 patients
Answer: 0.25% - 400 patients
ARR = |CER - EER| where CER = control group event rate (1%) EER = experimental group event rate (1% * [1- 0.25] = 0.75%) ARR = 1% - 0.75% = 0.25%
Power is:
a. Probability to detect statistically significance if one exists
b. A calculation of sample size
c. A calculation of validity
d. Positive predictive value
e. 1 – sensitivity
f. is not related to specificity
g. a stastistic that is not dependent on the prevalence
h. Calculation of the sample size needed to determine if a difference exists
Answer: Probability to detect statistically significance if one exists
The power of a trial is the probability of detecting a treatment effect of a given size, if one truly exists.[65] [66] [67] [68] Studies are usually designed to have a power of 0.80 or greater. Because the power of the trial is the chance of finding a true treatment effect, the quantity (1 - power) is the chance of missing a true treatment effect (i.e., risk of committing a type II error).[65] [67] The value of (1?β), or the power, and the magnitude of the treatment effect the clinical trial is designed to detect (defined by the alternative hypothesis) determine the sample size required for the study.[68]
Regarding statistical errors all are true EXCEPT:
a. The probability that the null hypothesis is considered false when it is true is called the beta
b. In a fixed sample population α error is inversely proportional to the β error.
c. Increasing the sample size decreases α error but doesn’t change the β error.
d. Power equals (1-beta)
Power: The probability of detecting an effect in the treatment vs. control group if a difference actually exists. Must also specify the size of the difference. For example, a paper describing a clinical trial with a new hypertension medication may contain the following statement - “The study had a power of 80% to detect a difference of 5 mm Hg in diastolic blood pressure between the treatment and control groups.” Typical power probabilities are 80% or greater. Power = 1 - ß
Type I Error: Mistakenly rejecting the null hypothesis when it is actually true. The maximum probability of making a Type I error that the researcher is willing to accept is call alpha (a). Alpha is determined before the study begins. False positive conclusion. Studies commonly set alpha to 1 in 20 (=0.05).
Type II Error: Mistakenly accepting (not rejecting) the null hypothesis when it is false. The probability of making a Type II error is called beta (b). Power = 1 - b (see above). False negative conclusion. For trials the probability of a b error is usually set at 0.20 or 20% probability. A 20% chance of missing a true difference.
Which is the most appropriate test to compare the means of 2 normal distributions?
a. Chi square
b. t-test
c. ANOVA
d. Fischer exact test
e. Variance
Answer: t-test
Student’s t test for independent samples is used to determine whether two samples were drawn from populations with different means.
Needs to be normally distributed population
A study has been designed to assess the wear properties of two different metal interfaces for total hip arthroplasty. There are 11 patients in one group and 13 in the other. Which test would best determine if a difference exists between these two groups?
a) t-test
b) Fischer exact test
c) Chi-square test
d) Linear regression
? T-test if the outcome is the same and normal distribution. Need more info.
Chi-square test - Used with categoric variables (two or more discrete treatments with two or more discrete outcomes) to test the null hypothesis that there is no effect of treatment on outcome; assumes at least five expected observations of each combination of treatment and outcome under the null hypothesis
Fisher’s exact test - Used similar to chi-square test; may be used even when fewer than five observations are expected in one or more categories of treatment and outcome
- Marx: Rosen’s Emergency Medicine, 7th ed.
Which test used to measure proportion :
a. Chi square
b. t-test
b. Nova
c. None of the above
d. All of the above
Answer: Chi square
To complete a retrospective study with a dichotomous outcome i.e. yes or no, the following tests could be used except:
a) Chi Square
b) Fischer T
c) Students T
d) Odds ratio
T-test
a) Chi Square (yes)
b) Fischer T (used for categorical data)
c) Students T (measure differenceb/w two means)
d) Odds ratio (yes)
Doing a study of femoral head size (26- 28-32 and 36) in conjuntion with rate of dislocation. What is the most appropriate statistical test? a - student t teat b – fisher exact test c – ANOVA d – chi squared
Chi squared?
Z-test/t-test tests differences between two sample means for continuous data.
Chi-square test - Used with categoric variables (two or more discrete treatments with two or more discrete outcomes) to test the null hypothesis that there is no effect of treatment on outcome; assumes at least five expected observations of each combination of treatment and outcome under the null hypothesis
Fisher’s exact test - Used similar to chi-square test; may be used even when fewer than five observations are expected in one or more categories of treatment and outcome
Analysis of variance compares mean values from three or more groups simultaneously
Define standard deviation. A. Difference between mean and median B. Measure of variance and dispersion C. The midpoint in a series of numbers D. Measure of dispersion around the mode
Answer: Measure of variance and dispersion
The standard deviation is the average deviation of scores around the mean of the variable for the set of observations in the sample. It is often designated SD.
- Tasman: Psychiatry, 1st ed
Given a normal distribution 1 standard deviation is:
a. 2/3
b. 99/100
c. 3/4
d. 1/3
e. None of the above
- 1 SD = 68%, 2 SD = 95%, 3 SD = 99%
The standard deviation is the square root of the variance. For a normally distributed population, 68% of values fall within 1 standard deviation of the mean and 95% of values within 1.96 standard deviations.
- Long: Principles and Practice of Pediatric Infectious Diseases, 3rd ed.
Patients are administered a survey with pain scale to check the effectiveness of a new non-steroidal antiinflammatory drug. The mean is 12, the mode is 8, median is 10, and SD is 11. Which of the following is true
a) most common value is 10
b) the average is 8
c) 68% of values will fall between 1 and 23
c.
a) most common value is 10 (8)
b) the average is 8 (12)
c) 68% of values will fall between 1 and 23 (12 +/-11) one SD
What is the variance of 3,6,9,11:
a. 3.00
b. 5.00
c. 7.00
d. 11.00
e. 29.00
Answer is none of the above. (12.25)
Summary of the calculation procedures:
- subtract the mean from each score
- square each result
- sum all the square
- divide the sum of square by N. Now you get variance
All of the following represent quantitative continuous data EXCEPT: A. Age B. BP C. Number of asthma attacks per month D. Height
Answer: Number of asthma attacks per month
Which of the following is an example of ordinal data? (Ordinal = order) A – stages of breast cancer B – ABO blood type C – sex D – Death / Life
Answer: stages of breast cancer
Ordinal data are categorical data where there is a logical ordering to the categories. A good example is the Likert scale that you see on many surveys: 1=Strongly disagree; 2=Disagree; 3=Neutral; 4=Agree; 5=Strongly agree.
- http://www.cmh.edu/stats/definitions/ordinal.htm
What does the Kaplan-Meier Curver measure?
Answer: survival
When using median as a measure of central tendency, when is it best?
a. slightly skewed
b. normal distribution
Answer: Normal distribution
The median is primarily used for skewed distributions, which it summarizes differently than the arithmetic mean. Consider the multiset { 1, 2, 2, 2, 3, 9 }. The median is 2 in this case, as is the mode, and it might be seen as a better indication of central tendency than the arithmetic mean of 3.166.
- for a normal distribution, mean = median = mode.
You have a mean of 12, median of 10, and average (?) (probably mean mode) of 8. What is the distribution? (where is the tail?)
a) Negatively skewed
b) Positively skewed
c) Normal distribution
Answer: Positively skewed
This is a positively skewed curve, because the mean is greater than the mode.
In probability theory and statistics, skewness is a measure of the asymmetry of the probability distribution of a real-valued random variable. The skewness value can be positive or negative, or even undefined. Qualitatively, a negative skew indicates that the tail on the left side of the probability density function is longer than the right side and the bulk of the values (possibly including the median) lie to the right of the mean. A positive skew indicates that the tail on the right side is longer than the left side and the bulk of the values lie to the left of the mean.
Negative skew: The left tail is longer; the mass of the distribution is concentrated on the right of the figure. The mean is smaller than the median.
Positive skew: The right tail is longer; the mass of the distribution is concentrated on the left of the figure. The mean is larger than the median.
Compare three groups of patients blood pressures. Which is appropriate test?
- Analysis of variance
- t test
- chi squared
Answer: Analysis of variance
Analysis of variance compares mean values from three or more groups simultaneously.
Chi-square test tests difference between proportions or tests for association between categories. Used when variable is categorical.
If the study has CI of 95%. What is the chance to have population out side this interval:
a. 1:5 (20%)
b. 1:10 (10%)
c. 1:20 (5%)
d. 1:95 (1-2%)
Answer: 1:20 (ie 5%)
In which situation would a surgeon not be liable?
a) Failure to diagnose a breast lump
b) Undue delay in diagnosing a malignant breast lump
c) Performing a mastectomy without explaining the other options
d) Failing to refer for adjuvant chemotherapy
e) Recurrence of breast malignancy, when patient has entered a clinical trial of adjuvant therapy
e) Recurrence of breast malignancy, when patient has entered a clinical trial of adjuvant therapy
They consent to this
In the OR, the surgeon is responsible for:
a) Anesthesiologist
b) Scrub nurse
c) Secretary in office
d) Med student observer
- Med student observer
The surgeon is responsible for:
a. The anesthesiologists
b. The OR nurses
c. The student observers
d. The secretaries he employees in his office
- The secretaries he employees in his office
A patient undergoes surgery and a complication arises. Surrounding the issue of disclosure, which of the following is correct:
a) the patient doesn’t need to know of any medical errors which took place if there are no immediate consequences
b) the patient should be informed of all medical errors as is their right for autonomy
c) disclosure of medical errors often leads to lawsuits
d) every attempt should be made to prevent the patient from learning about the medical error
b?
Disclosure of medical errors.
A – more ligation if error is disclosed
B – no legal obligation to disclose error
C – disclosure is in keeping with principles of automony
D – only disclose if there is harm to patient and they will find out anyways
- disclosure is in keeping with principles of automony?
Which is most associated with the authorship of a publication:
a) participated in the writing of the paper
b) provided lab space
c) developed the background behind the hypothesis question
d) responsible for the content of the publication
e) assisted in the technical aspect of the experiment
f) provision of grants
Answer: responsibility for content of the publication
6 yr old kid is in car crash. Dad is killed. Mom is alive and OK. Mom is Jehovah’s witness. Kid urgently needs transfusion and laparotomy. Mom insists that kid be given no transfusion. What to you do?
a. disregard Mom, take kid to OR, give blood as needed to save her
b. call children’s aid society
c. obey Mom’s wishes no matter what the expected outcome
d. arrange for a substitute decision maker to give consent for OR and transfusion
Disregard Mom, take kid to OR, give blood as needed to save her. Kid is too young/does not have the capacity to reject treatment/be Jehovah? No time to call CAS - deal with it later.
Rule: Must contact CAS but if threat is imminent, then transfuse right away
Post-op a patient is found to have unresectable pancreatic ca. The patient has a history of depression and the wife asks you to not tell him for he would not be able to cope mentally. Your next course of action should be:
a. tell the patient
b. give the patient a forum to ask about operative findings and their interest in knowing all details
c. Lie to the patient
- give the patient a forum to ask about operative findings and their interest in knowing all details
A 67 year old male undergoes an emergent laparotomy for peritonitis. He is noted to have a perforated cecal carcinoma with intraperitoneal carcinomatosis and multipe metastasis to his liver. After telling the family the bad news and explaining to them his poor prognosis, they ask you not to tell him of his dismal prognosis. You the surgeon should:
a. Consult the hospital lawyer
b. Consult the hospital ethics review board
c. Explain to the family your obligation to your patient and tell the patient
d. Explain to the family your obligation to your patient and tell the patient only if he asks
e. Do as the family wishes
- Explain to the family your obligation to your patient and tell the patient
Patient plans on committing a violent crime, what should you do:
a. Nothing
b. Document it in the chart and tell no body
c. Tell the police
d. Discuss it with patient
Answer: Tell the police
Duty to Warn (look it up)
If there is a threat, then you should tell police, person in question, or holding person against will
Patient is planning to sue a surgical team whom you treated few weeks age. He came to ER with intestinal obstruction and you are the oncall for surgery. what should you do:
a. Refuse to see and treat the patient
b. Transfer him to another hospital
c. See the patient and ask a doctor who was not involved in his treatment before to look after him
d. ask the patient not to suit the team if he wants to be treated
Answer: See the patient and ask a doctor who was not involved in his treatment before to look after him
Patient with advanced metastatic cancer. When wants every thing to done for him. You think he should be palliative and DNR. What kind of discussion will not be appropriate:
a. Negotiation
b. Arbitration
c. Rationalism
Answer: Arbitration
Arbitration – legal technique for the resolution of disputes outside of courts, wherein the parties to a dispute refer it to one or more persons, by whose decision they agree to be bound
Negotiation – a process of resolving disputes and conflicts via talks and discussions without using force
Rationalism – any view appealing to reason as a source of knowledge or justification
Autonomy – capacity of a rational indivdual to make a informed, uncoerced decision
After opening of the abdomen of a patient with you staff in the OR, You as a junior resident found out that your staff is drunk, What should you do:
a. Continue the procedure
b. Take over and let scrub out
c. As him to close the abdomen and reschedule the procedure
d. Tell the chief.
Answer: Tell the chief.
You are newly licensed, and are preparing to do your first total hip replacement as staff surgeon. Your obligation is:
a) Tell the patient this is your first one
b) Tell the patient this is your first one, and refer to someone more experienced
c) Don’t disclose to patient, because you did several as a resident
d) Don’t disclose to patient, because having your specialty certification implies a level of competence
A?
The legal standard of risk disclosure expected of a physician hinges on the interpretation of the entity called “material risk.” Any impairment of the physician related to drug usage, disease, or alcohol which compounds the risk of a procedure is very likely to be considered material by a patient. This paper argues that physician inexperience is a factor that a reasonable patient would attach significance to and that it should therefore be viewed as a “material risk” requiring disclosure.
In attempting to practice medicine that pays attention to minimizing economic burden/appropriate resource use, you should do all of the following, EXCEPT:
a) Avoid inappropriate tests
b) If choice exists, use less costly materials
c) Give your patients advantages
d) Treat patients on first-come first-serve basis
c) Give your patients advantages
d) Treat patients on first-come first-serve basis (also a silly thing since a prescription refill should not be seen before a trauma)
A patient tells you that he intends to harm another person. What is your legal responsibility?
a) Chart the incident and tell no one
b) Inform the person in question
c) Call psych
d) Inform the police
d) Inform the police (this is legally what you should be doing)
Duty to warn
You are doing a laminectomy on a patient, and mistakenly entered the dural space (i.e., dural tear). You should:
a) Repair and no further management required
b) Don’t tell patient about complication, but monitor for CSF leak post-operatively
c) Tell patient about intra-op complication, possible sequelae, and what to look for (i.e., symptoms of CSF leak)
d) Call the hospital lawyer, and risk management
c) Tell patient about intra-op complication, possible sequelae, and what to look for (i.e., symptoms of CSF leak)
Negligence is breach of legal duty. Definition is all except:
1) Physican has duty to patient
2) Duty was breached
3) Patient is harmed
4) Harm is direct cause of break of duty
5) Physician provides good care
5) Physician provides good care
Negligence = Not doing the standard of care, which is what another reasonable physician would have done in the same situation. NB: cannot be blamed unless this would have affected the patient → poor outcome (doesn’t count if it doesn’t influence management).
A 75 yo male with newly diagnosed adenocarcinoma in his right lower lobe presents with ischemic bowel. Preoperatively he says that he doesn’t want any heroic measures taken. Postoperatively he remains intubated, and develops renal failure. If you withhold hemodialysis, which of the following is true?
a. Liable for negligence.
b. Liable in a civil lawsuit by family.
c. Would be deemed unethical by his colleagues.
d. Would suffer no consequences.
Answer given: Liable for negligence
One could argue hemodialysis is not a heroic measure.
After finishing your research under supervision of your staff you are leaving to another lab. You are obliged / entitled to :
a. Take all research material with you.
b. Ask permission to take a copy to continue with your own research.
c. Leave a copy in case data are required for research authentication.
d. Not take anything
Answer: Not take anything
Patient in ER unconscious, driver other car killed, you smell Etoh. Police ask for blood sample for etoh level
A – give it to them
B – draw blood for you and give result only if court order
C – draw blood for your use and save sample for police
D – draw blood for police if patients family consents
Answer: draw blood for you and give result only if court order
The confidentiality of patient information is prescribed in law. For example, physicians in Ontario are prohibited from providing information to third parties regarding a patient’s condition or any professional service performed for a patient without the consent of the patient or his or her authorized agent unless such disclosure is required by law.[2] A breach of confidentiality that is not required by law may prompt disciplinary action by the College of Physicians and Surgeons of Ontario. Similar provisions concerning confidentiality exist in other provinces. Moreover, a breach of confidentiality may result in a civil suit.
CMAJ ethics online
http://collection.nlc-bnc.ca/100/201/300/cdn_medical_association/cmaj/vol-156/issue-4/0521.htm
A patient is not capable of making their own decision. which is not an appropriate way to seek guidance about medical decisions? a- personal directive b – family members c – appointed patient advocate d – hospital staff
d (consent)
Informed consent must includes all of the following except:
a. general risk
b. specific risk
c. alternative therapy
d. percentage of failure and success
e. Special and unique risks
e. special and unique risks
The law presumes that an adult is mentally competent to make medical decisions and that the competent adult is entitled to sufficient information to make an informed decision concerning the physician’s proposed course of examination and treatment.[74] Under the doctrine of informed consent, physicians have the duty to disclose the following information to patients[74-76]:
- The patient’s condition and/or diagnosis
- The nature and purpose of the proposed treatment, including the likelihood of success in the physician’s practice
- Reasonable alternative measures related to the diagnosis and treatment, including the probable outcome of those alternatives
- The particular known inherent risks that are material to make an informed decision about whether to accept or reject the proposed treatment, including the consequences of refusing that treatment
- Marx: Rosen’s Emergency Medicine, 7th ed.
All are true regarding obtaining consent EXCEPT:
a. Disclosure.
b. Voluntary
c. Capacity.
d. Has to be written.
Answer: Has to be written (implied consent ex: lifting up your sleeve for someone to give you a vaccine)
A pregnant woman is brought to the trauma suite with substantial intra-abdominal trauma. She expresses that she is a Jehovah’s witness and cannot accept blood or blood product transfusion. Her baby is stable at present. Patient consents to undergo surgery and intra-operatively, the patient becomes hypotensive, placing the unborn child at risk. Of the following people, who has the right to act on the patient’s behalf as POA in aiding in the decision making in this situation:
a) the baby’s biological father
b) the patient’s common-law partner
c) the patient’s sibling
d) the physician
b) the patient’s common-law partner
order of SDM when patient is not capable (ex: under GA?)
In disclosure, one must discuss with the patient:
a-what a reasonable physician would say
b-what a reasonable patient wants to know
c-what a reasonable patient in those circumstances needs to know
For consent to be valid, it must be informed. The patient must be provided all relevant information. To be valid, it must also be voluntary, that is, as free from coercion as possible while recognizing that in extremis the patient’s condition itself may be inherently coercive. The surgeon’s ethical objective is to judiciously provide the patient sufficient information with which to decide what course to follow. This entails selectively presenting all information pertinent to the patient’s condition regarding benefits, risks, and alternatives while avoiding overwhelming the patient with extraneous data. To walk the line between what is pertinent and what is extraneous requires prudent judgment.
- Townsend: Sabiston Textbook of Surgery, 18th ed.
While you are explaining the risks of surgery to a patient with breast cancer she appears not to be listening and says that she doesn’t want to hear these bad things and wants you to do the operation. You should:
a. Insist that she listens or you will cancel the surgery.
b. Consult another surgeon to try to explain the procedure.
c. Ask a next of kin or a patient advocate to assess the risks and benefits.
d. Document that you explained the risks and proceed with the surgery.
Answer given: Ask a next of kin or a patient advocate to assess the risks and benefits
A 45 y old man is rushed to the OR after identification of a leaking aortic aneurysm on CT scan in the trauma evaluation following a high speed MVC. The patient declares that he is a Jehovah’s witness and therefore consented to the surgery but not to the administration of any blood or blood products. During the surgery the patient’s blood pressure falls and it becomes clear the patient will likely not survive without blood transfusions. The nurse then comes into the OR stating that the wife is outside and threatens to sue you unless you do everything you can to save her husband, emphasizing that you should administer blood if that’s “what he needs”. The most appropriate action at this time is:
a) listen to the wife because she is the POA while the patient is incapable of making this decision on his own under the general anesthetic
b) administer blood and disguard the evidence
c) do not administer any blood products and continue to rescusitate the patient to the best of your ability
Answer: Support with crystalloid but don’t give blood
Which of the following applies to consent EXCEPT?
a. not a discreet process but continuous
b. finished once you sign on the dotted line
b
A 57 year old male undergoes a resection of his left parotid gland for adenocarcinoma. Upon waking he is unable to smile on his left side. The intern who did the pre-operative history and physical and obtained the consent did not list or explain the complications of this surgery to the patient or their family.
As the surgeon of record, you should
a) call the hospital legal counsel immediately
b) avoid discussing this finding with the patient
c) fail the intern
d) explain to the patient what has happened
e) consult plastic surgery for a sural nerve graft
Answer: explain to the patient what has happened
PSA screening and its increase in detection and decrease in mortality is invalidated by all EXCEPT one of the following:
a) lead time bias
b) length time bias
c) overdetection
d) selection bias
e) stage migration
Answer: stage migration (???)
Bias is a systematic error in making inference (assumptions). Any bias would invalidate results, therefore a), b) and d) are not correct answers.
Stage migration describes change in the distribution of stage in a particular cancer population induced by either a change in the staging system itself or else a change in technology which allows more sensitive detection of tumor spread and therefore more sensitivity in detecting spread of disease (e.g., the use of MRI scan). Stage migration can lead to curious statistical phenomena.
- http://en.wikipedia.org/wiki/Cancer_staging
Which carries the GREATEST risk of life-threatening post-op cardiac complication for non-cardiac surgery? A. CHF B. Greater than 5 PVC/min C. MI within last 6 months D. Arterial pO2
Answer: CHF
Based on goldman classification CHF has the highest score
Which one of the following is not associated with an increased cardiac mortality
a. surgery
Answer: intraoperative hypotension or class II angina ??
Exposure in operating room personal leads to increased risk of:
Answer: Spontaneous abortion (old data, likely not to be on our exam cause looks like it’s no longer the case)
Answer: Spontaneous abortion
[…] Nevertheless, as late as 1997 a meta-analysis of over 19 studies completed between 1984 and 1992 reported an RR of abortion in females exposed to anesthetic gases to be 1.48 (CI 95%) 1.4-1.58.
[…] This preliminary report showed the incidence of infertility, spontaneous abortion and children with congenital abnormalities in female anesthesiologists to be the same as that in other physicians […]
No definitive evidence has shown that trace concentrations of anesthetics in the ambient air of the operating room present a health hazard.
- Miller: Miller’s Anesthesia, 7th ed.101 – Environmental Safety Including Chemical Dependency
There used to be “strong” evidence but now mostly debunked.
Diabetic on insulin and had MI 18 months going to inguinal hernia:
a. ASA II
b. ASA III
c. ASA IV
d. ASA V
Answer: ASA III
I. A normal healthy patient.
II. A patient with mild systemic disease.
III. A patient with severe systemic disease.
IV. A patient with severe systemic disease that is a constant threat to life.
V. A moribund patient who is not expected to survive without the operation.
VI. A declared brain-dead patient whose organs are being removed for donor purposes.
1) ALL of the following carry high mortality rate except:
a. Gallop 3 (CHF)
b. MI 18 months
c. Valve disease
d. CAGB 3 years ago
CABG 3 years ago
2) Highest risk of major cardiac event following noncardiac surgery
a. presence of heart failure
b. subendocardial infarct in last 2 months
Presence of heart failure
3) Which of the following does not increase the risk of a peri-operative MI
a. mi within the previous 6 months
b. angina functional class II
c. s3 gallop
d. aortic stenosis
e. age > 70 years
3) Angina functional class II
Perioperative MI probably is the leading cause of death in elderly after noncardiac surgery;
- presence of CAD increases the incidence of peri-op MI from 0.1 to 0.7-1.1%; >40 with or without CAD: infarction rate is 1.8%; previous MI, reinfarction rate is 5-8%; MI within 3 months: reinfarction rate is 27%; 3-6 months: 11%; >6months: 5%;
- patients with EF 35%); thus, CHF is a higher risk.
a. mi within the previous 6 months - 10 points
b. angina functional class II - not on the cardiac risk index (class III and IV are)
c. s3 gallop (CHF) - see above
d. aortic stenosis - 20 points for critical aortic stenosis
e. age > 70 years- 5 points
Healthy smoker patient going for surgery. All are correct except
a. At least ASA II
b. High postoperative complication
c. High risk of wound infection
Answer: High postoperative complication
A 62 year old female patient presents as a same day surgery patient. A preoperative EKG reveals a LBBB. The patient denies any symptoms and has no cardiac history. The most appropriate course of action is to:
a. Proceed with surgery
b. Proceed with the surgery, but use regional anesthesia rather than general anesthesia
c. Reschedule surgery and arrange a pre-operative anesthesia consult
d. Cancel the surgery and have the patient admitted to cardiology
e. none of the above
c. Reschedule surgery and arrange a pre-operative anesthesia consult
A patient with a new LBBB could have had an infarct. Considering this is elective surgery, the best course of action is to delay the operation and has the patient assessed by anesthesia.
Unlike RBBB, which is occasionally seen without evident cardiac disease, LBBB is usually a sign of organic heart disease. LBBB may develop in patients with long-standing hypertensive heart disease, a valvular lesion (e.g., calcification of the mitral annulus, aortic stenosis, or aortic regurgitation), or different types of cardiomyopathy (see Chapter 11 ). It is also seen in patients with coronary artery disease and often correlates with impaired left ventricular function. Most patients with LBBB have underlying left ventricular hypertrophy (see Chapter 6 ). Rarely, otherwise normal individuals have an LBBB pattern without evidence of organic heart disease by examination, echocardiogram, or even invasive studies.
Important clinical consideration: LBBB may be the first clue to four previously undiagnosed but clinically important abnormalities. These are advanced coronary artery disease, valvular heart disease, hypertensive heart disease, and cardiomyopathy.
- Goldberger: Clinical Electrocardiography: A Simplified Approach, 7th ed.
Which factor would not be decreased in hepatic failure?
a. 2
b. 5
c. 7
d. 8
e. 10
The liver is the major site of synthesis of all the coagulation factors except factor VIII
- Townsend: Sabiston Textbook of Surgery, 18th ed.
What factor converts prothrombin to thrombin
a. Factor IX
b. Factor X
c. Factor XI
10 (actually Xa and Va)
A 22 y old male is to undergo elective surgery on the knee. In order to get the goal factor VIII of 60-80% normal, what can you do regarding perioperative planning:
a) give replacement factor before the surgery and for 10 days following
b) administer factor VIII immediately after the surgery
c) administer Factor VIII for 2 doses pre-operatively, and one dose post-op
d) give Factor VIII for 5 days following surgery
Answer: give replacement factor before the surgery and for 10 days following
In elective surgery, levels of the deficient coagulation factor should be assayed 48 hours before surgery and the level restored to 40% of normal before surgery. Because the half-life is 6 to 10 hours for factor VIII (8h for factor 8) and 8 to 16 hours for factor IX, approximately 1.5 U/hr/kg of factor VIII or 1.5 U/2 hr/kg of factor IX should be given. Additional administration of factors VIII and IX should be guided by the activity of the clotting factors for about 6 to 10 days postoperatively.
- Miller: Miller’s Anesthesia, 7th ed.
A 36 year old otherwise healthy male with Hemophilia A is about to undergo surgery. His factor VIII level is 80% normal. Which scenario appropriately predicts his post-operative course?
a) No increased risk of bleeding
b) A minor increase in bleeding risk
c) A moderate increase in bleeding risk
d) A major increase in bleeding risk
e) Is not safe to undergo surgery
D. nothing. unlikely spontaneous bleed if >5-10%
Hemophilia A is inherited as a sex-linked recessive deficiency of factor VIII, with fewer cases secondary to spontaneous mutation. The incidence of this abnormality is about 1 in 10,000 births. Clinical findings range from bleeding into joints and muscles, epistaxis, hematuria, and bleeding after minor trauma to prolonged postoperative bleeding, retroperitoneal bleeding, and intramural bowel hemorrhage. Laboratory screening tests usually reveal a prolongation of aPTT, with other tests being normal. The minimum level of factor VIII required for hemostasis is 30%, and spontaneous bleeding is uncommon with factor VIII levels greater than 5% to 10% of normal. Levels less than 2% constitute severe, 2% to 5% moderate, and greater than 5% mild deficiency. Severe deficiency with levels less than 1% are at risk for spontaneous bleeding episodes. Although the half-life of factor VIII is 2.9 days in normal subjects, the half-life of factor VIII concentrates is only 9 to 18 hours. Levels between 80% to 100% of normal should be attained for surgical bleeding or life-threatening hemorrhage. Acquired deficiency has been reported to occur with the development of antibodies to factor VIII after therapy.
- Greenfield CD, ch 4
What levels are required for a hemophiliac to undergo elective surgery? 100% 60-80% 20-40% greater than 10%
In elective surgery, levels of the deficient coagulation factor should be assayed 48 hours before surgery and the level restored to 40% of normal before surgery. Additional administration of factors VIII and IX should be guided by the activity of the clotting factors for about 6 to 10 days postoperatively
- Miller: Miller’s Anesthesia, 7th ed.
To achieve hemostasis for major surgical procedures, an initial level of 60 to 100 percent is achieved. This level is followed by a prophylactic level of 30 to 50 percent until the wound is healed, typically 10 to 14 days. After some orthopedic procedures, factor level may need to be maintained for a longer period of time.
Pt with Haemophilia, the lowest acceptable level for elective surgery
a. 10%
b. 20%
c. 40%
d. 60%
(depends on the site of operation/risk of bleeding):
a. 10%
b. 20%
c. 40% = elective surgery
d. 60% = major surgery and high risk of bleeding
To achieve hemostasis for major surgical procedures, an initial level of 60 to 100 percent is achieved. This level is followed by a prophylactic level of 30 to 50 percent until the wound is healed, typically 10 to 14 days. After some orthopedic procedures, factor level may need to be maintained for a longer period of time.
1) A woman in hospital is bleeding. The INR is noted to be normal but the activated Partial Thromboplastin time (aPTT) is elevated. Which of the following MOST likely explains her problem? A. Medication induced B. Warfarin C. Deficiency of factor VII D. Unrecognized bleeding dyscrasia
Answers:
1) Medication induced (most likely heparin for inpatients)
2) A patient has a prolonged PTT but normal INR. Which of the following could BEST explain these findings?
a. deficiency of factor VII
b. deficiency of factor VIII
c. dysfibrogenemia
d. X inhibitor
b. deficiency of factor VIII
a. deficiency of factor VII (INR)
b. deficiency of factor VIII (yes, intrinsic pathway)
c. dysfibrogenemia (both)
d. X inhibitor (both)
3) Bleeding patient has normal INR but abnormal APTT , most likely cause is :
a. Platelet dysfunction.
b. Drug induced coagulation defect.
c. Undiagnosed bleeding dyscriasis.
d. Cirrhosis.
Undiagnosed bleeding dyscriasis.
a. Platelet dysfunction. (depends, may be both)
b. Drug induced coagulation defect. (depends on factors inovolved)
c. Undiagnosed bleeding dyscriasis.
d. Cirrhosis. (Both)
4) young, male patient, pre-op for elective surgery, found to have isolated prolonged PTT, with no history of bleeding problems, most likey diagnsosis
a. lack of factor XI
b. lack of factor XIII
c. acquired antibody to factor VIII
4) lack of factor XIII
When aPTT is performed in conjunction with PT (INR), a further clarification of coagulation defects is possible. For example, a normal INR with an abnormal aPTT means that the defect lies within the first stage of the (intrinsic) clotting cascade (factors VIII, IX, X, XI, and/or XII). The pattern of a normal aPTT with an abnormal INR suggests a possible factor VII deficiency (extrinsic). If both INR and aPTT are prolonged, a deficiency of factor I, II, V, or X is suggested (common pathway). Used together, APTT and INR will detect approximately 95% of coagulation defects.
Patient bleeds after dental extraction. Bleeding time and aPTT increased but INR is normal. Normal capillary frag. and clot retraction.
a. VW
b. Factor IX
c. Glandsmans disease
d. Factor VII
Answer: a. VW
vWF has 2 functions
1) platelet aggregation (bleeding time)
2) carrier for factor 8 (intrinsic pathway – PTT)
- aPTT prolonged in (Factor 12, 8, 9, 11 – deficiencies), Lupus Anticoagulant,
- Activated partial thromboplastin time (aPTT): Measures intrinsic system; requires factors V, VIII, IX, X, XI, XII, fibrinogen, and prothrombin. May be prolonged in heparin administration, in hemophilia, in von Willebrand disease (vWD), in DIC, and in the presence of circulating inhibitors (e.g., lupus anticoagulants or other antiphospholipid antibodies).
- Prothrombin time (PT): Measures extrinsic pathway; requires factors V, VII, X, fibrinogen, and prothrombin. May be prolonged in warfarin administration, in deficiencies of vitamin K–associated factors, in malabsorption, in liver disease, in DIC, and in the presence of circulating inhibitors.
- Bleeding time (BT): Evaluates clot formation, including platelet number and function, and von Willebrand factor (vWF). Performed at patient’s bedside. Always assess the platelet number and history of ingestion of platelet inhibitors, such as nonsteroidal anti-inflammatory drugs, before a BT test. The Platelet Function Analyzer-100 (PFA-100) system is another in vitro method for measuring platelet and vWF function.
- Johns Hopkins: The Harriet Lane Handbook, 18th ed.
Which of the following mechanisms BEST explains the coagulopathy associated with severe hemorrhagic shock?
A. Decreased circulating coagulation factors
B. Decreased circulating platelets
C. Acidosis and hypothermia
D. Increased fibrinolysis
Answer: Acidosis and hypothermia
The wording of this question is a bit misleading. The acidosis and hypothermia are usually associated with transfusion, not the shock itself.
What is the half-life of factor VIII? A. 3-6 hours B. 8-12 hours C. 1-2 days D. 4-7 days
Easy way to remember: factor 8 = 8 hours.
vWF stabilizes factor VIII, which has a half-life of about 2.4 hours when free and 12 hours when bound to vWF in the circulation.
- Kumar: Robbins and Cotran Pathologic Basis of Disease, Professional Edition , 8th ed.
In its circulating form, factor VIII is inactive or minimally active as a cofactor in blood coagulation. It circulates in the blood at very low concentration (100 ng/mL) bound to vWF. Its plasma half-life is approximately 8 to 12 hours.
- Hoffman: Hematology: Basic Principles and Practice, 5th ed.
Because the half-life is 6 to 10 hours for factor VIII ….
- Miller: Miller’s Anesthesia, 7th ed.
1) Which factor deficiency is MOST likely to cause a high INR but normal PTT? A. VII B. VIII C. IX D. XI
Answers given:
1) VII
INR : 1972 : X, IX, VII, II (rules out B and D in 1st stem)
Hemophilia B is Factor IX deficiency : elevated PTT (rules out C)
Also, VIII, IX, and XI are in intrinsic (PTT) pathway, while VII is extrinsic pathway (INR)
Profiles of Hemostasis Screening Tests in Patients with Bleeding Disorders
2) Patient with normal PTT and prolong PT with INR 1.5 which factor is
a. Factor VIII.
b. Factor VII.
c. Factor II.
d. DIC
b. Factor VII
Extrinsic pathway
- The ONLY Factor Deficiency that DOES NOT prolong aPTT = 7
Disorders of the Extrinsic Pathway of Coagulation
A prolonged prothrombin time and a normal aPTT suggest an isolated deficiency of factor VII, which is rare and may be the result of an inherited or an acquired abnormality. Less commonly, inhibitors to factor VII have been reported. Additionally, certain cases of DIC or dysfibrinogenemia may present with isolated prolonged PT values. Because factor VII is essential only in the tissue factor-activated extrinsic pathway of coagulation, the coagulation time and the Stypven time are normal in patients with this disorder.
- Lee: Wintrobe’s Clinical Hematology, 10th ed., Copyright © 1999 Lippincott Williams ; Wilkins
3) All of the following would increase the INR EXCEPT:
a) Factor II deficiency (affects both)
b) Factor V deficiency (affects both)
c) Factor VII deficiency
d) Factor X deficiency (PTT)
e) Factor XI deficiency (PTT)
Factor XI deficiency
a) Factor II deficiency (affects both - common pathway)
b) Factor V deficiency (affects both - common pathway)
c) Factor VII deficiency (only INR - extrinsic pathway)
d) Factor X deficiency (affects both - common pathway)
e) Factor XI deficiency (intrinsic pathway only)
1) All of the flowing are causes of hypercoaguability except:
a) Decreased activated protein C
b) Venous stasis
c) Immobility
d) Neoplasm
e) Increase functional protein S
1) Increase functional protein S
protein C + S are “anticoagulants”
Protein C and S deficiencies lead to a hypercoagulable state
2) Which of the following is responsible for a hypercoagulable state?
a. High protein S
b. Low protein C
c. Low factor VIII
d. Low fibrinogen
2) Low protein C
protein C + S are “anticoagulants”
Protein C and S deficiencies lead to a hypercoagulable state
Hypercoagulability that occurs with birth control pills is due to:
a. Increased antithrombin III
b. Decreased Protein S
c. Increase protein S
d. Factor II deficiency
e. Platelet dysfunction
f. Increased factor VII
B+F: Increased factor VII, decrease in protein S
a. Increased antithrombin III (bleeding)
b. Decreased Protein S (clot)
c. Increase protein S (bleeding)
d. Factor II deficiency (bleeding)
e. Platelet dysfunction (bleeding)
f. Increased factor VII (clot)
The mechanism by which oral contraceptives are prothrombotic is complex and uncertain. Prothrombotic effects include modest increases in the levels of procoagulant factors (factor VII, factor VIII, factor X, prothrombin, fibrinogen) and decreases in the levels of anticoagulant proteins (antithrombin III, protein S). The development of acquired APC resistance has been demonstrated, by means of a thrombin generation assay, in women taking oral contraceptives. Although the molecular basis for this phenomenon is unknown, it provides a plausible explanation for the greatly increased thrombotic risk among oral contraceptive users who are carriers of the factor V Leiden mutation.[4]
- Hoffman: Hematology: Basic Principles and Practice, 5th ed.
Oral contraceptives cause alterations of the vessel wall with intimal hyperplasia. They also increase blood viscosity. There are decreased levels of protein S, antithrombin activity, and plasminogen activator content in women taking oral contraceptives. There also may be an increase in the levels of fibrinogen, factor VII, and factor X.
- Bradley: Neurology in Clinical Practice, 5th ed.
The estrogen component of combination OCs increases hepatic production of serum clotting factors, particularly factors I (fibrinogen), VII, and X
- Noble: Textbook of Primary Care Medicine, 3rd ed., Mosby, Inc. p.332
Which factor deficit is seen with vitamin K deficiency?
a. II
b. V
c. IX
d. XI
e. XII
Not sure..
Factor VII has the shortest half-life of all the factors carboxylated by vitamin K; therefore, when deficient, it is the PT that rises first, since the activated Factor VII is the first to “disappear.” In later stages of deficiency, the other factors (which have longer half lives) are able to “catch up,” and the PTT becomes elevated as well.
old answer:
This isn’t mentioned in common texts. The following might suggest factor II is most sensitive marker ….
When there is mild vitamin K deficiency, the PT is normal, but there are elevated levels of the undercarboxylated forms of the proteins that are normally carboxylated in the presence of vitamin K. These undercarboxylated proteins are called proteins induced by vitamin K absence (PIVKA). Measurement of undercarboxylated factor II (PIVKA-II) can be used to detect mild vitamin K deficiency
- Kliegman: Nelson Textbook of Pediatrics, 18th ed.
FDP (Fibrin degradation product ~ D-dimer) is a result of:
a. Conversion of plasminogen to plasmin
b. Conversion of fibrinogen to fibrin
c. By product of RBCs degradation
d. All of the above
e. None of the above
Answer: Conversion of plasminogen to plasmin (well, almost)
Plasminogen activators convert plasminogen to plasmin. Plasmin then degrades fibrin into soluble fibrin degradation products.
- Hoffman: Hematology: Basic Principles and Practice, 5th ed.
In a DIC picture all of the following are true except:
a. Low D dimer
b. High D dimer
c. High platelets
d. Fibrinogen High
e. None of the above
Answer: A and D.
I think A makes most sense based on below explanation and the fact that A and B are contradictory (so one must be the right one)
Laboratory abnormalities in DIC are variable and related to the many diseases associated with this condition. Common abnormalities include an abnormal PT and aPTT with depressed fibrinogen levels and abnormal platelet counts. Levels of fibrin degradation products and d-dimer are elevated. The peripheral smear reveals fragmented RBCs, but this finding is not specific. Because of the continued activation of coagulation, thrombin/antithrombin complexes will be formed. Levels of thrombin/antithrombin and AT-III are depressed. Fragments of coagulation factor degradation are elevated, including F1.2 and FpA. Because of activation of the fibrinolytic system, plasminogen and α2-antiplasmin inhibitor levels are decreased.
- Townsend: Sabiston Textbook of Surgery, 18th ed.
Another feature of disseminated intravascular coagulation, hypofibrinogenemia, is unlikely to contribute to a defect in platelet aggregation, except in extreme cases, as fibrinogen concentration in plasma exceeds by at least 10-fold the quantity needed to saturate fibrinogen receptors on platelets.
- Hoffman: Hematology: Basic Principles and Practice, 5th ed.
Hmmm … based on the stem both A and D are possible.
What is the mechanism of action of Epsilon-aminocaproic acid (Amicar) in the treatment of DIC?
a) decreased fibrinolysis by inhibiting plasminogen activators
b) activation of complement cascade
c) activation of intrinsic pathway
d) induction of prostacyclin production
e) inhibitor of thrombin-anthrombin complex
Answer: decreased fibrinolysis by inhibiting plasminogen activators (similar to tranexamic acid)
Amicar is an antifibrinolytic that inhibits plasminogen to plasmin conversion thereby inhibiting fibrinolysis by plasmin
An antifibrinolytic for treatment of excessive bleeding from fibrinolysis. Competitively inhibits activation of plasminogen to plasmin, also, a lesser antiplasmin effect
What is the physiologic mechanism of thrombolytic therapy?
- transformation of plasminogen into plasmin
- transformation of fibrinogen into fibrin
- inhibition of factor V
- inhibition of factor VIII
- inhibition of factor XIII
Logical answer: inhibiting factors would prevent further thrombosis without lysing current clots. fibrin causes clots. therefore plasminogen/plasmin is the answer
(Urokinase and Streptokinase increase Plasminogen → Plasmin formation) ⇒ Increase Plasmin activity ⇒ Increase Fibrinolysis
What is the best measure of the extrinsic pathway of hemostasis?
PT/INR
aPTT
Thrombin time
Bleeding time
PT/INR
which of following is reduced in obstructive jaundice:
a. Prothrombin
b. Fibrinogen
c. Factor XIII
d. Factor VIII
Answers:
- a. Prothrombin (factor II)
The uptake of the vitamin is intimately linked to the liver, as biliary salts are required for intestinal absorption.[10] Vitamin K deficiency can therefore be caused by anything that impairs the metabolism of bile acids. This includes intra- or extrahepatic cholestasis, biliary system fistulae or obstruction, primary biliary cirrhosis, or treatment with bile acid binders (i.e., cholestyramine).
Vitamin K serves as a coenzyme in the post-translational carboxylation of factors II, VII, IX, and X.[18] This modification creates sites on these proteins for calcium ion coordination and thereby renders them functional
Cause of increased bleeding in Obstructive jaundice is :
a. Decreased fibrinogen
b. Decreased absorbtion of Vit K
c. Decreased platelet function
b. Decreased absorbtion of Vit K
The uptake of the vitamin is intimately linked to the liver, as biliary salts are required for intestinal absorption.[10] Vitamin K deficiency can therefore be caused by anything that impairs the metabolism of bile acids. This includes intra- or extrahepatic cholestasis, biliary system fistulae or obstruction, primary biliary cirrhosis, or treatment with bile acid binders (i.e., cholestyramine).
Vitamin K serves as a coenzyme in the post-translational carboxylation of factors II, VII, IX, and X.[18] This modification creates sites on these proteins for calcium ion coordination and thereby renders them functional
What will activate the coagulation cascade during acute inflammation:
a. Factor XIII
b. VII
c. X
d. Prekallikrein
Answer: b. VII (extrinsic pathway, trauma)
Activator of extrinsic Pathway:
-Tissue factor comes into contact with factor 7
Activator of Intrinsic Pathway:
-Factor 12 binding to negatively charged surfaces (ex proteins)
Tissue kallikrein can also form bradykinin. Plasma kallikrein and bradykinin are activated during the acute and chronic phases of several experimental rat models of small intestinal ulceration and granulomatous enterocolitis, with a pathogenic role indicated by suppression of inflammation by a specific kallikrein inhibitor. [243] [244] Of considerable interest, genetic susceptibility to intestinal and systemic inflammation in inbred rat strains correlated with activation of the contact system[245] and is mediated by a single nucleotide polymorphism in kininogen that encodes a defect in glycosylation that accelerates cleavage by kininogen.
- Feldman: Sleisenger amp; Fordtran’s Gastrointestinal and Liver Disease, 8th ed.
Inflammation and blood clotting are often intertwined, with each promoting the other.[74] The clotting system is divided into two pathways that converge, culminating in the activation of thrombin and the formation of fibrin ( Fig. 2-15 ) ( Chapter 4). The intrinsic clotting pathway is a series of plasma proteins that can be activated by Hageman factor (factor XII), a protein synthesized by the liver that circulates in an inactive form. ***Factor XII is activated upon contact with negatively charged surfaces, for instance when vascular permeability increases and plasma proteins leak into the extravascular space and come into contact with collagen, or when it comes into contact with basement membranes exposed as a result of endothelial damage. Factor XII then undergoes a conformational change (becoming factor XIIa), exposing an active serine center that can subsequently cleave protein substrates and activate a variety of mediator systems (see later). Inflammation increases the production of several coagulation factors, makes the endothelial surface pro-thrombogenic, and inhibits anticoagulation mechanisms, thus promoting clotting.
- Kumar: Robbins and Cotran Pathologic Basis of Disease, Professional Edition , 8th ed.
What is the most common inherited factor deficiency:
a. Factor V deficiency
b. Factor VII
c. Factor VIII
d. Factor IX
Answer: c. Factor VIII
vWF is actually more common > VIII > IX > XI
a. Factor V deficiency (1 in million)
b. Factor VII (1/500 000)
c. Factor VIII (1/5000, X linked)
d. Factor IX (1/30 000)
vWF deficiency 1/100 (asymptomatic) - 1/10000 (symptomatic)
Which does not increase INR
a) Coumadin
b) heparin
c) decreased factor VII
Answer: b) heparin
In addition to the administration of warfarin, there are other causes of prothrombin time prolongation. These include (show table 1):
- Vitamin K deficiency due, for example, to poor nutrition, or prolonged use of broad spectrum antibiotics.
- Severe liver disease, which decreases the synthesis of both vitamin K-dependent and -independent clotting factors.
- Deficiency or inhibition of factors VII, X, II (prothrombin), V, or fibrinogen
- The infrequent antiphospholipid antibodies (lupus anticoagulant phenomenon) with antiprothrombin activity. In such patients, the acquired prothrombin deficiency may be severe enough to cause clinical bleeding. (
- While treatment with heparin does not normally prolong the PT (due to the addition of heparin-neutralizing materials to the PT reagent), the PT may be transiently elevated after heparin bolus administration.
Increase INR (Extrinsic pathway)
- Warfarin, Vitamin K deficiency
- Factors 10, 9, 7, 2 Deficient (7 MOST IMPORTANT)
- Liver Disease, DIC
A girl intentionally slashes her wrist. Despite applying pressure, the bleeding continues. Why is this?
a) retained foreign body
b) complete laceration of radial artery
c) partial transection of a major vessel
Likely B
Most common protein spilled in trauma?
a) glutamine
b) valine
c) alanine
a. Glutamine
The pattern of changes in amino acid concentration in muscle during catabolism shows an increase in branched-chain amino acids, aromatic amino acids, and methionine, and a decrease in glutamine and basic amino acids (lysine and arginine). A uniform reduction of approximately 50% of free muscular glutamine associated with negative N balance seems to be one of the most typical features of the response to trauma and infection
Glutamine is the most abundant amino acid in the human body, comprising nearly two thirds of the free intracellular amino acid pool. Of this, 75% is found within the skeletal muscles. During stress states such as sepsis, or
in tumor-bearing hosts, peripheral glutamine stores are rapidly depleted, and the amino acid is preferentially shunted as a fuel source toward the visceral organs and tumors, respectively. (Schwartz)
Options of treatment of rhabdomyolysis:
a. fluid resuscitation until u/o > 0.5 cc/kg/hr
b. mannitol
c. bicarbonate
Answer: fluid resuscitation until u/o > 0.5 cc/kg/hr
Rhabdomyolysis is the breakdown of muscle fibers with leakage of potentially toxic cellular contents into the systemic circulation. The final common pathway of rhabdomyolysis may be a disturbance in myocyte calcium homeostasis.[
Vigorous hydration with isotonic crystalloid is the cornerstone of therapy for rhabdomyolysis. Administer isotonic crystalloid 500 mL/h and titrate to maintain a urine output of 200-300 mL/h
Urinary alkalinization is recommended for patients with rhabdomyolysis and CK levels in excess of 6000 IU/L. Alkalinization should be considered earlier in patients with acidemia, dehydration, or underlying renal disease. A suggested regimen is 0.5 isotonic sodium chloride solution with one ampule of sodium bicarbonate administered at 100 mL/h and titrated to a urine pH higher than 7.
After establishing an adequate intravascular volume, mannitol may be administered to enhance renal perfusion.
Loop diuretics may be used to enhance urinary output in oliguric patients, despite adequate intravascular volume.
- http://emedicine.medscape.com/article/827738-treatment
Clinical sequelae of rhabdomyolysis include the following:
• Hypovolemia (sequestration of plasma water within injured myocytes)
• Hyperkalemia (release of cellular potassium into the systemic circulation)
• Metabolic acidosis (release of cellular phosphate and sulfate)
• Acute renal failure (nephrotoxic effects of liberated myocyte components)
• Disseminated intravascular coagulation (DIC)
• Hypocalemia (from phospate binding to calcium)
In a high pressure solvent injection, prognosis is best indicated by?
Answer: delay to OR
Synonyms: “high-pressure injection injury,” “grease gun injury,” “paint gun injury,” “pressure gun injury,” and “high-pressure injection.”
Worsens with:
• Greater time from injury to decompression/debridement
o>10 hours – very high rate of amputation
• Chemical/toxic nature of injectant
o Amputation rate 60-80% paint/solvents; 7000 -100% rate of amputation
• Velocity of injectant
• Secondary infection
oMay develop oleogranulomas (grease and oil based compounds) – drain through skin (fistulas/sinus)
• Portals of entry
o more distal worse
o digits: into tendon sheath poor
o palm: better because not governed by fascial planes
• MUST warn patients even if digit survives – will be left with painful, stiff, atrophic digit. Prepare for poor outcome and possible later ankylosis/amputation
A young man presents to the emergency department with a nearly complete circumferential laceration to the right arm. The wound itself is extremely dirty. After ample irrigation you should:
a) perform a primary closure in the ER
b) perform a primary closure in the OR
c) Perform a mechanical debridement
d) Harvest a skin graft to cover the defect
Answer: Perform a mechanical debridement
All are life threatening condition except:
a. Open femur fracture – embolis and infection
b. B/L femur fracture – embolis
c. Traumatic arm amputation – bleed out
d. Thigh compartment syndrome
Answer: Thigh compartment syndrome
a. Open femur fracture – embolis and infection
b. B/L femur fracture – embolis
c. Traumatic arm amputation – bleed out
d. Thigh compartment syndrome
What is the most common cause of death in children:
a. Congenital heart disease
b. Leukemia
c. Trauma
d. Infection
Answer: Trauma
#1 Unintentional Injury Age 1-4 11.1/100000, 5-14 6.8/100000 (of this MVA>drowning (1-4) and firearms (5-14)) #2 Congential Malformations 3.6/100,000(1-4) amp; Malignant Neoplams 2.4/100,000(5-14) (source National Center for Health Statistics 2001)
5 year old boy involved in MVA. They showed you a normal CXR and AXR. His SaO2 is 84% difficult bagging. What is you next step:
a. Lt chest tube
b. Rt chest tube
c. Intubate and ventilate
d. Pericardiocenthesis
Answer: Intubate and ventilate
35yo male trauma to lower extremity 2h ago. Which most likely determines limb salvage vs amputation?
a. Post tib. Nerve injury
b. Vascular injury
c. Segmental bone loss
d. Contamination
a. Post tib. Nerve injury
b. Vascular injury - fix the vascular injury
c. Segmental bone loss - bone graft
d. Contamination - debride
Posterior tibial nerve doesn’t exist. I think they mean tibial nerve. If you don’t have tibial nerve you can’t feel the sole of your foot, and it’s a contraindication to salvage
“two absolute contraindications for lower limb salvage: anatomical complete disruption of the posterior tibial nerve in adults and crush injuries with warm ischemia time of more than 6 hours” - again, posterior tibial nerve isn’t technically correct but it’s cited in this article http://www.hindawi.com/journals/tswj/2014/640430/
Patient involved in MVC. “Damage control” surgery appropriate in all except the following:
a) Uncontrolled arterial bleeding
b) Unstable, hypotensive patient
c) Patient temp 34 degrees (a core body temp less than 32 during laporotomy is considered unitversally fatal)
d) Patient lactate >5 (indication of anerobic metabolism and possible loss of blood)
c) Patient temp 34 degrees (a core body temp less than 32 during laporotomy is considered universally fatal)
There is convincing evidence from multiple clinical series that a damage control strategy can be lifesaving in patients with severe injury. With such a strategy the surgeon limits interventions during the first operation to those that stop the bleeding and enable the patient to be resuscitated from hemorrhagic shock. In damage control, the surgeon selects a point in the first operation when the basic life-threatening problems have been managed and then decides to stop operating and return the patient to the ICU for resuscitation and correction of body temperature, acidemia, and coagulation disorders.
- Townsend: Sabiston Textbook of Surgery, 18th ed.
Indications for damage control surgery
Thoracic trauma
• Penetrating injury and SBP 5 (indication of anerobic metabolism and possible loss of blood)
Trauma patient scenario. When is the most appropriate time to order X Rays?
a. as soon as the patient arrives in the emergency department
b. before the primary survey
c. after the primary survey
d. after C spine is controlled and there is intravenous access
e. after the secondary survey is finished
c. After the primary survey.
Based on ATLS, the phases of emergency department care are divided into the primary survey with interventions, initial diagnostics and imaging, the secondary survey, and disposition.
- Marx: Rosen’s Emergency Medicine, 7th ed.
Radiographs of the chest, pelvis, C-spine, and FAST are adjuncts to the primary survey.
Imaging is considered helpful but should be used judiciously and should not interrupt or delay the resuscitation process. When appropriate, radiography may be postponed until the secondary survey.
- Kool, Blickman. Advanced Trauma Life Support®. ABCDE from a radiological point of view. Emerg Radiol. 2007 July; 14(3): 135–141.
Order from ATLS : Primary survery Resuscitation Adjuncts to primary surgery and resuscitation Consider need for patient transfer Secondary survery Continued post-resuscitation monitoring and re-evaluation Definitive care
Guy suffers anterior shoulder dislocation and complains of numbness over upper lateral shoulder, muscle most likely to be affected
- biceps
- triceps
- deltoid
Answer: deltoid
Anterior Shoulder Dislocations
A careful assessment of the neurovascular status of the affected extremity is essential. Injury to the axillary artery is rare, usually occurring in the elderly,[13] and can be quickly assessed by palpation of the radial pulse or the presence of an expanding hematoma. It is important to assess the status of the axillary nerve, because this is the most common nerve lesion resulting from anterior dislocations.[14] The sensory component of the axillary nerve is assessed by testing for sensation over the lateral aspect of the upper arm ( Fig. 49–5 ). The motor component of the axillary nerve would be tested by assessing the strength of the deltoid muscle, a difficult undertaking in the patient with a dislocated shoulder.
- Roberts: Clinical Procedures in Emergency Medicine, 5th ed.
Girl falls off horse has a seizure –stable in emerg, negative ct scan. What is management?
a) Observe
b) load with dilantin,
c) MRI
Answer dilantin.
What is the best indicator of likelihood of focal seizure post-head trauma?
a) GCS
ATLS book
15% of patients with severe brain injury will have seizure
Severe definted as GCS 3-8
Approximately 5-10% of individuals with traumatic brain injury (TBI) experience new- onset seizures. The risk of seizure increases with increasing injury severity, depressed skull fracture, intracranial hematoma, and penetrating trauma. The risk is greatest in the first two years after injury and gradually declines thereafter. All types of seizures may occur as a result of trauma, but the most frequent are focal or partial complex seizures. Generalized complex seizures (what are commonly called “grand mal’ seizures) occur in approximately 33% of cases.
Immediate onset seizures, those that occur immediately or in the first few hours after a brain injury, do not suggest a chronic seizure disorder. Early onset seizures and those which develop within the first 7-8 days after trauma require prophylaxis for up to one year. Spontaneous resolution of seizure activity has been noted in this group. The highest risk group for persisting seizures are those individuals who experience seizure 7-8 days or longer following injury. Current recommendations for seizure prophylaxis suggest that patients who have not suffered a seizure within the first 7-8 days following a closed head injury, probably do not require prophylaxis
Posttraumatic seizures (PTS) frequently occur after moderate or severe TBI. Seizures are usually general or partial, and absence seizures are uncommon. Seizures are classified according to the time elapsed after the initial injury: Immediate seizures occur in the first 24 hours. Early seizures occur in the first 2-7 days, and late seizures occur after 7 days. The incidence of late PTS is in the range of 5-18.9%. Risk factors include chronic alcoholism, older age at the time of injury, and a history of seizure disorder. Approximately one half to two thirds of patients with these risk factors develop late PTS within the first year after injury.16 If a patient with TBI has 1 PTS, his or her likelihood of having another is approximately 50%. - http://emedicine.medscape.com/article/326643-overview
A 6 week old baby in a trauma to stabilize head on a spine board, the head must be: a-parallel to board b-20 degrees flexed c-20 degrees extended d-some other position?
Answer: 20 degrees extension
Examination of a child with a suspected spinal injury is carried out with the patient supine, in a neutral position, after the head and neck have been stabilized. In small children, it is appropriate to place a pad beneath the trunk to avoid hyperflexion of the neck because of the disproportion in head size.
- Green amp; Swiontkowski: Skeletal Trauma in Children, 4th ed.
A young male is involved in an MVA. He sustains a closed head injury and on presentation has a decreased GCS, BP 90/50, HR = 105, RR = 20 and an increased ICP at 22mmHg. All of the following are acceptable courses of action EXCEPT (2 answers): A. Propofol and intubation B. Lasix, 40mg IV C. Mannitol, 20mg/kg IV D. IV morphine for pain control E. Raise bed to 30 degree incline, head up F. Hyperventilate to PCO2 of 34-36 G. Dexamethasone
B. Lasix, 40mg IV and G. Dexamethasone
Glucocorticoids — Glucocorticoids were associated with a worse outcome in a large randomized clinical trial (CRASH) of their use in moderate to severe head injury. They should not be used in this setting.
Other agents — Furosemide, 0.5 to 1.0 mg/kg intravenously, may be given with mannitol to potentiate its effect. However, this effect can also exacerbate dehydration and hypokalemia (this patient is hypotensive)
Management of Elevated Intracranial Pressure
- Prevention of venous engorgement
- CO2 control (mild hyperventilation) NORMOCAPNEA and NORMOXIA
- Sedation and pain control
- Cerebrospinal fluid drainage
- Mannitol
- Lasix
- Hypertonic saline
- Decompressive craniectomy
- Pentobarbital coma - used as last-ditch effort
Bope: Conn’s Current Therapy 2010, 1st ed
ICP is normally 0–10 mm Hg; at 20–25 mm Hg, the upper limit of normal, treatment to reduce ICP is needed.
Propofol decreases intracranial pressure (ICP) in patients with either normal or increased ICP.
Patient post MVC. MRI showed diffuse brain edema. Patient is agitated in the ICU. What would be the best kind of medication for sedation for 1-2days:
a. Midazolam
b. Lorazepam
c. Propofol
d. Morphine
Propofol does not increase ICP and can be run as an infusion.
Sedation — Keeping patients appropriately sedated can decrease ICP by reducing metabolic demand, ventilator asynchrony, venous congestion, and the sympathetic responses of hypertension and tachycardia [72]. Establishing a secure airway and close attention to blood pressure allow the clinician to identify and treat apnea and hypotension quickly.
Propofol has been utilized to good effect in this setting, as it is easily titrated and has a short half-life, thus permitting frequent neurologic reassessment.
When are flexion/extension views contraindicated?
A. Midline cervical tenderness
B. Diagnosed Brown-Sequard syndrome
C. Patient can flex and extend neck without assistance
D. When a ligamentous injury is suspected
E. Spinal shock
F. Anterior cord syndrome
Answer: Brown-Sequard
- the flexed view is usually most helpful in detecting ligamentous injury that is not apparent on the neutral view
- typically, this view is ordered at 7 to 10 days post injury when C-spine is less tender
Contraindications :
- known cervical spine fracture or dislocation
- Brown sequard, central cord
- not with anterior cord syndrome
In alert patients with normal plain radiographs but persistent symptoms, flexion-extension views, especially of the cervical spine, can be obtained to look for ligamentous instability.
- Townsend: Sabiston Textbook of Surgery, 18th ed.
Central cord syndrome is a contraindication to flex-ex.
Flex-ext stress views should obtained for only those who are alert, cooperative, and neurologically intact and patients who can describe pain or early onset of any subjective neurologic symptoms
Brown-sequard: hemisection of cord. Asymmetric paresis and jt position/vibration loss (ipsilateral) with contralateral pain and temperature loss.
Ant. Cord syndrome: disproportionately greater motor impairment in upper compared to lower extremities, bladder dysfunction, and variable degree of sensory loss below the level of injury. Typically after hyperextension injury. Flex-Ext views indicated
Neuro injury in multisystem trauma due to
a. vasopressors
b. toxins
c. perfusion
Answer: perfusion
In addition, polytrauma patients can present with hypotension caused by ongoing hemorrhage, resulting in a critically low perfusion to a potentially swollen, injured spinal cord. As with brain injury, prolonged hypoperfusion and hypoxia may be harbingers of poor outcome.
- Bradley: Neurology in Clinical Practice, 5th ed.
A young healthy male involved in a MVA suffers a closed head injury. He remains hypotensive despite 2 L of crystalloid. The likely cause is:
a. SIADH
b. intracranial bleed
c. unrecognized intra-abdominal injury
Answer: unrecognized intra-abdominal injury
SIADH would make you hypertensive
Which of the following is the worst prognostic indicator in head injury?
a. cerebral hypoxia
b. systemic hypotension
c. age
d. co-morbid illness
Which is the best prognostic factor after TBI a – initial GCS b – Lack of a sub dural c – Age d – Moving all four limbs
Not sure what the answers are… probably A for the second question
PROGNOSIS — Outcome from severe head injury is dependent on a range of factors including baseline patient characteristics, severity of TBI, and the occurrence of medical complications and secondary brain insults. Specific negative outcome predictors that have been identified from these factors include :
●GCS at presentation (especially the GCS motor score)
●Presence and severity of CT abnormalities (subarachnoid hemorrhage, cisternal effacement, midline shift)
●Pupillary function
●Age
●Associated injuries and complications
●Hypotension
●Hypoxemia
●Pyrexia
●Elevated ICP
●Reduced CPP
●Bleeding diathesis (low platelet count, abnormal coagulation parameters)
Snowmobile accident, severe head injury and hypotensive. Why?
a. Hemmorhage
b. Spinal cord injury
c. Medulla injury
Hypotension is always hemhorrage until proven otherwise ?
The most common cranial nerve injured in trauma:
a. I
b. II
c. III
d. IV
e. V
CN 1
Posttraumatic single nerve palsy was observed in 38 patients (77.6%), and multiple nerve injuries were observed in 11 (22.4%). Cranial nerves were affected in 62 cases. The most affected CN was the olfactory nerve (CN I), followed by the facial nerve (CN VII) and the oculomotor nerves (CNs III, IV, and VI).
Other cranial nerve injuries — The risk of injury to other cranial nerves increases with the severity of brain injury, but these can also occur in mild TBI with an incidence of 0.3 percent according to one case series [143]. The distribution is similar to that for moderate or severe head injuries:
●Anosmia and hyposmia, which are often reported by the patient as impaired taste as well as smell, occur following injury to olfactory filaments as they enter the brain through the cribiform plate. While recovery occurs in about one-third of patients, loss of smell is likely permanent if present one year after the injury [144]. (See “Anatomy and etiology of taste and smell disorders”.)
●Diplopia may result from injury to cranial nerves III, IV, and VI. In the setting of mild TBI, injury to cranial nerve IV is most common, followed by VI. Cranial nerve III is less commonly affected by mild TBI. (See “Overview of diplopia”.)
●Facial pain and occipital neuralgia may occur in association with mild TBI. The former usually occurs in the setting of blunt force injury to the trigeminal nerve in the face, while occipital nerve injury may be indirect from a contiguous musculoskeletal injury in the neck. (See “Overview of craniofacial pain”.)
A patient is brought to the emergency department following an injury. On arrival, his eyes are closed, he is mumbling incoherently, and he localizes to pain. What is his GCS?
a. 6
b. 7
c. 8
d. 9
e. 10
d. 9
E1V3M5 = 9
his eyes are closed (do not open to command) = 1, he is mumbling incoherently = 3, and he localizes to pain = 5
Defintion of incoherent: without logical or meaningful connection; disjointed; rambling
Patient was involved in MVA. Presented with decreased LOC and ecchymosis around eyes and behind ears. What is the most common cause:
a. LeFort II
b. Basal skull fracture
c. Intracerebral bleeding
d. ????
Answer: Basal skull fracture
Raccoon eyes, battle’s sign
Blurb of basal skull #, and otorrhea. What is the best option?
a. Treat with broadspectrum Abx and observe
b. Swab ear and treat Abx specific
c. Consult neurosurg for OR
d. Consult ENT for OR
e. Observe and consult if drainage continues
e- Observe and consult if drainage continues
Realistically should get neurosurg assessment, but the key to answering this question is to know that 1. usually the CSF leaks stop on their own (so don’t need urgent OR), and 2. you don’t need to give prophylactic antibiotics. See below for more details.
Basal skull fractures involve the floor of the skull. Bruising may occur about the eye (raccoon sign) or behind the ear (Battle’s sign), suggesting a fracture involving either the anterior or middle fossa, respectively. Isolated cranial nerve deficits can be seen in association with this fracture type because the nerves’ exit foramina lie at the skull base. The facial nerve is frequently affected, with injury due to laceration or swelling. Most facial nerve deficits resolve spontaneously, so no specific therapy is warranted. On the other hand, complete transections of the facial nerve are usually explored, although the timing of exploration remains a matter of debate.
Any associated CSF rhinorrhea or otorrhea should be treated expectantly. Traumatic CSF leaks typically stop within the first 7 to 10 days. If a leak persists, lumbar CSF drainage can be implemented to seal the leak by lowering CSF volume and ICP. If drainage therapy fails, surgical exploration is indicated and accomplished by oversewing the defect with an intradural fascial patch graft. Fewer than 5 percent of patients require surgical repair. Prophylactic antibiotics are not used routinely because recent prospective studies have failed to demonstrate any benefit from their use.
- Schwartz
Uptodate
Basilar fractures — Intracranial hemorrhage caused by a basilar skull fracture frequently represents a surgical emergency and requires immediate neurosurgical consultation. All patients with basilar skull fractures require admission for observation, regardless of the need for surgical intervention.
Basilar skull fractures can produce a dural tear, which can cause a cerebral spinal fluid (CSF) leak. Clinically, this is suggested by the presence of clear or blood-tinged rhinorrhea or otorrhea in a head-injured patient. If the fluid is blood tinged, the “halo” sign (also called the “ring” or “target” sign) may be useful to determine the presence of CSF.
To perform the test, a drop of the fluid is placed on a tissue or filter paper. A rapidly expanding ring of clear fluid around red blood defines a positive test. Of note, the halo test does NOT differentiate among CSF, saline, saliva, and other clear fluids and has not been formally studied in a clinical setting. (See “Facial trauma in adults”, section on ‘Examination of specific body parts’.)
The majority of CSF leaks resolve spontaneously within one week of injury and without CNS complications. The risk of meningitis has been estimated at 3 percent in the first week. Retrospective observational studies suggest that the administration of prophylactic antibiotics during the first week of a CSF leak is unnecessary [46-49]. The incidence of bacterial meningitis rises substantially if the leak persists past seven days and we suggest that prophylactic antibiotics be given in such cases [46]. Antibiotic selection is identical to that for penetrating head trauma. (See ‘Penetrating injuries’ below.)
Cranial nerve palsies are a delayed complication of basilar skull fractures. They generally present two to three days following injury and are due to nerve compression or contusion [50,51]. These palsies may respond to treatment with glucocorticoids, although no large clinical trials have been performed to support this approach. Common treatment regimens are similar to those used for nontraumatic palsies (eg, Bell’s palsy). We suggest starting such treatment in consultation with otolaryngology or neurosurgery. (See “Bell’s palsy: Pathogenesis, clinical features, and diagnosis in adults”.)
Facial nerve palsies that appear acutely in association with basilar skull fractures are due to nerve transections. These injuries do NOT respond to glucocorticoid therapy and carry a poor prognosis for recovery of nerve function [45].
70 year old male patient was involved in MVA. Vitally stable with no complaint but could not recall what happened. What is the most appropriate
action:
a. Discharge home
b. CT head
c. Skull x-ray
d. Intubation
Answer: CT Head because he is >65 years old
Canadian CT Head Rule
CT Head Rule is only required for patients with minor head injuries
with any one of the following:
High risk (for neurological intervention) ● GCS score 30 min ● Dangerous mechanism (pedestrian struck by motor vehicle, occupant ejected from motor vehicle, fall from height >3 feet or five stairs)
Minor head injury is defined as witnessed loss of consciousness, definite amnesia, or witnessed disorientation in a patients with a GCS score of 13–15.
Man brought into emerg after falling at shopping mall. HR, BP, RR all normal, neuro exam normal. Well-healed pacemaker scar. Evidence of malar # (Zygomaticomaxillary complex fracture). Can’t remember events of fall. In addition to arranging for repair of #, you should do:
a) EKG; pacemaker interrogation
b) ECHO
c) CT head
d) Stress test
Similar question:
Elderly man brought into the ER after a fall. Past history includes a pacemaker. Although he could not recall the incident he is now mentally clear with nothing to find on exam except for a malar fracture. What is the most appropriate investigation?
a. CT scan with contrast
b. MRI
c. Stress EKG
d. Resting EKG and pacemaker check.
? I think further details on stem would help. Unsure if this is a syncope question or CT head rule question
For the second, CT is likely the answer. Hard to argue EKG vs. stress EKG so likely those two are not the answer. MRI is almost always contraindicated if you have a pacemaker