Week 14 - Preoperative Assessment Flashcards
What is the purpose of a preoperative assessment?
Help identify factors that increase the risk associated with anesthesia and the status of the patient relative to the proposed surgery.
What has been found to be more predictive of surgical complications over objective preoperative lab testing?
A preoperative history and physical
What are some of the benefits of pre anesthesia assessment clinics?
Reduction in –> patient anxiety, direct cost, last minute cancelations, overall length of hospitalization and diagnostic testing
Improvement in –> Patient education
What is the purpose of a pre anesthesia assessment clinic?
Allows patients scheduled for elective surgery to be evaluated and their condition optimized sufficiently in advance of surgery.
What are some conditions that would benefit from early preoperative evaluation?
Medical conditions inhibiting ADL’s, angina, CAD, history of MI…
Patients with complex medical conditions should be evaluated ________ __________ prior to the scheduled surgery.
one week
Who must preform the pre anesthesia assessment?
An anesthesia provider
True or False
The timing of the pre anesthesia assessment does not appear to influence the outcome of anesthesia?
True
When looking at preoperative diagnostic tests, where should these be obtained from if not collected during the patients current admission?
Directly from the original source –> Prevents misinterpretation
What can be collected from progress notes and consultation results?
Health history, physical status, medical treatments (drug dosages and schedules)
Diagnostic test results should NOT be collected from here because this increases the likelihood of misinterpretation
Where can baseline data concerning the patient be collected from (coping mechanisms and patient limitations)?
Nursing notes
How should the preoperative interview be conducted in a patient who has completed the pre anesthesia questionnaire?
Questions should be directed towards abnormal findings and areas of concern
Why should the preoperative assessment be conducted in a way that doesn’t feel rushed?
Patients degree of trust and confidence is enhanced.
What is something that increases the patients perception of time you spent with them during the pre-operative assessment?
Sitting rather than standing –> Results in more positive exchanges and more comprehensive understanding of their circumstances
What should occur prior to performing the preoperative assessment once entering the room?
A request that visitors step out unless the patient wishes for them to be present –> Allows patient to be more honest and volunteer health information easier (substance abuse, sexual history).
What are the objectives of the preoperative interview?
What are the patient education objectives during the preoperative interview?
What can be done if the surgeon has already documented a thorough medical history and physical exam prior to your pre anesthesia evaluation?
The interview can focus on confirming major findings and obtaining information pertinent to anesthesia care –> Anesthesia provider must obtain and document a detailed health history.
Where can patient surgical history be obtained from?
From the chart or preoperative interview.
Vague reports of fever and convulsions the last time a patient underwent anesthesia requires what?
Further investigation –> Need to rule out malignant hyperthermia
Why must familial anesthetic history be obtained?
Because numerous diseases affecting anesthesia can be inherited –> MH, atypical plasma cholinesterase, porphyria, or glycogen storage diseases.
What should be done in patients taking nonessential medications prior to surgery?
Have patient discontinue all forms of non-essential medications
True or False
The majority of medications are discontinued pre operatively?
False –> Majority of medications are continued, besides non-essential medications. Medications that DO need to be withheld should be for 3-5 half lives.
What are the most common drug allergies during anesthesia?
NMBA and antibiotics
Why do side effects and allergic reactions need to be distinguished?
Because a side effect isn’t a reason to withhold a drug, whereas a true allergic reaction is.
What other medications should be avoided if the patient present with a true drug allergy?
Medications from that class.
20% of intra operative anaphylactic reactions have been attributed to what?
Latex allergies
When is a preoperative latex allergy testing indicated?
Only when a family history of latex allergy is present or a report of patient symptoms such as rash, swelling, or wheezing when exposed to latex.
Skin prick test is most sensitive
What patients are at high risk for latex allergies?
Industrial workers, spina bifida, repeated surgical procedures (more than 9), allergies to food and tropical fruits, health care professionals, intra operative anaphylaxis of unknown cause
How should patients be questioned about social history (drug/alcohol intake)?
Open ended questions posed in a non judgemental way
Should be educated on why this information is important for us to know as it can necessitate the need for higher than normal sedative amounts
What is the leading cause of preventable premature death in the USA?
Cigarette smoking
Symptoms of acute nicotine intoxication in children?
Seizures, coma, respiratory arrest, and death
Effects of nicotine on the cardiovascular system?
It is a toxic alkaloid –> Causes increased BP, HR, and can cause atherosclerosis
How much greater is carbon monoxides affinity for oxygen than hemoglobin?
250-300 times greater
How long should patients quit smoking prior to surgery?
At least 12-48 hours
What is the half life for nicotine? Carbon monoxide?
Nicotine –> 40-60 minutes
Carbon monoxide –> 130-190 minutes
How can smoking cessation for just one night prior to surgery be beneficial?
Reduces HR, BP, and circulating catecholamine levels. Also allows carboxyhemoglobin to return to normal levels
Effects of passive/second hand smoke in children?
Increased reactive airway diseases, abnormal results of pulmonary function tests, and increased RTI.
Peri operatively –> Laryngospasm, coughing on induction or emergence, breath holding, postoperative oxyhemoglobin desaturation, and hypersecretion.
Alcohol attributable deaths has been found to shorten the lives of those who die by ___________ years
29
What self reporting questionnaire can be used to gauge alcoholic problem drinkers? What is a less confrontational approach?
Alcohol Use Disorders Identification Test (AUDIT)
CAGE –> Less confrontational, 4 questions.
If yes to two questions –> High risk for alcoholism
Both assessments have been shown to be effective in identifying the abusive alcohol drinker.
Effects of tobacco smoking?
Prolonged wound healing, reduced bone density and osteoporosis, COPD…
Physiologic impact of components in E-cigarettes?
What is important to determine in the heavy drinker?
If they have experienced seizures, abrupt withdrawal syndrome, and delirium tremens
What are some clinical signs of alcohol withdrawal?
Increased hand tremors, autonomic hyperactivity, insomnia, anxiety, restlessness, N/V, transient hallucinations, psychomotor agitation, and grand mal seizures.
What anesthetic requirements are increase in a chronic alcoholic?
Patients require increased amounts of hypnotics, opioids, and inhalation agents.
In an alcoholic, when are exaggerated responses to anesthetics likely?
Acute intoxication or advanced alcoholism
Enzymatic function and plasma albumin may be _____________ in patients with alcoholic hepatic insufficiency during acute intoxication or advanced alcoholism.
Decreased –> Greater circulating concentrations of unbound intravenous agents can result in an exaggerated or prolonged effect.
Has not been shown to occur with propofol in moderate liver cirrhosis
What are the complications leading to increased morbidity and mortality in alcoholic patients?
Poor wound healing, infection, bleeding, pneumonia, and further hepatic deterioration.
Why can an accurate illicit drug history be difficult to obtain?
Patient’s fear of legal ramification and to believe a problem exists.
What signs indicate illicit drug use?
Track marks/scarring, ophthalmologic changes, lymphadenopathy, malnourishment, poor dental care and bruxism, nasal perforation from cocaine abuse
What should occur if you believe a patient is under the influence of drugs prior to surgery?
Drug screening –> If positive, elective case is canceled.
What are some signs and symptoms of acute substance abuse?
What illicit drugs generally cause euphoria?
Cannabis and Opioids
What does illicit drug abstinence syndrome manifest with?
Increased sympathetic and parasympathetic responses –> HTN, tachycardia, abdominal cramping/diarrhea, tremors, anxiety, irritability, lacrimation, mydriasis, algid sweat, and yawning.
What three drugs are used to help with opioid abstinence?
MAT –> Medically assisted treatment for abstinence of opioids
Methadone –> Opioid de-addiction
Suboxone –> Maintenance of opioid abstinence
Naltrexone –> Maintenance of abstinence with opioids or management of cravings in alcohol abuse
For patients undergoing MAT (Medically assisted treatment for abstinence of opioids), what can be done to allow for their current MAT (Methadone, suboxone, or naltrexone) treatment throughout the perioperative period?
Multimodal pain management plan –> Combo of regional, local, long acting anesthetics…
Synthetic androgens can result in dysfunction of what body systems?
Hepatic and endocrine
What should be done if patients are in doubt as to what herbal supplements they are taking?
They should be encouraged to bring them to their pre operative workup
These supplements should be discontinued 2-3 weeks PRIOR to anesthesia if practical
Why is the patient asked not to phonate when protruding their tongue during the Mallampati assessment?
Because this can elevate the soft palate.
What joint does inter incisor distance assess?
Temporomandibular joint –> Should be able to open the mouth 4 cm or 2-3 finger breadths
This joint can experience limitations after the induction of anesthesia in some populations when they could open their mouth normally during the pre operative assessment.
What would be suspected in patients with limited atlantooccipital joint movement?
Cervical arthritis or a small C1 gap
–> This inhibits the patient from being able to be placed in a sniffing position
What should be done during the preoperative assessment if the anesthesia provider in concerned with the patients teeth?
Informed consent needs to be signed with the patient understanding the increased risks (broken teeth), this protects the provider from legal ramification.
When should partial plates or dentures be left in place during anesthesia?
Only if it improves the mask fit
Ideal body weight formula
Male –> 105 lbs plus 6 pounds each inch over 5 feet
Female –> 100 lbs plus 5 pounds each inch over 5 feet
20% over ideal body weight constitutes obesity
2x ideal body weight constitutes morbidly obese
BMI formula
BMI = weight in kg/meters^2
Gold standard test to diagnose sleep apnea?
Polysomnography
What is the most common screening tool used for identifying high risk individuals for sleep apnea?
STOP-Bang –> Yes to 3 or more question = high risk
Signs and symptoms of sleep apnea?
History of snoring, apneic episodes, frequent arousals during sleep, morning headaches and daytime somnolence
What are some co morbidities associated with obesity?
What should patients who use a CPAP at home be instructed to do prior to surgery?
Bring CPAP device with them so it can be used in the post anesthesia care unit.
What patients are at high risk for adrenal insufficiency?
Those who have received corticosteroids (hydrocortisone) of more than 20 mg daily for 3 weeks during the previous year AND those who are receiving replacement therapy for adrenal insufficiency.
Why should the least amount of steroid therapy be used in a patient at risk of adrenal insufficiency?
To minimize the risk of surgical site infection and postoperative wound complications
What are some signs and symptoms of increased intracranial pressure and ischemia? What usually causes this?
Most often due to vasospasm after a subarachnoid hemmorhage
What can a patient with rheumatoid arthritis present with during intubation?
This disease can be compounded with restrictions in vocal cord movement or tracheal stenosis caused by cricoarytenoid arthritis
A patient with a Glasgow Coma Score of less than ________ often requires TI with mechanical ventilation.
8
What patients are at greatest risk of peripheral neuropathy?
Patients with long standing diabetes, uremia, and chronic alcoholics with nutritional deficits –> Would benefit from a neurology consult with a preoperative electromyography.
Even a slight ________ midline shift in the brain can be seen on CT/MRI and confirm suspicious of intracranial HTN
0.5 cm
What can an arteriographic film (angiogram) be used to test?
Allows to visualize the inside or lumen of blood vessels and organs –> Shows which vessels are experiencing occlusion/partial occlusions and can be used to determine the degree of collateral circulation in a patient with cerebrovascular occlusive disease
What should be avoided in patients with cerebrovascular occlusive disease with vertebral involvement
Extremes in head positioning –> Extreme head flexion, extension, or rotation should be avoided.
Why should sedatives be avoided in patients with increased intracranial pressure?
Because sedatives cause altered LOC which will mask the altered LOC the patient experiences if the patients condition worsens
What drugs are patients with intracranial HTN extremely sensitive to?
CNS depressants such as opioids
What blood work should accompany phenytoin?
CBC –> Patient at risk for agranulocytosis
Serum concentrations of what 2 anticonvulsants DO NOT need to be documented unless drug withdrawal or significant changes are expected?
Phenytoin and Phenobarbital
Should anticonvulsants be continued peri operatively in most cases?
Yes
Why is corticosteroid therapy used and continued peri operatively for patients presenting with a CNS tumor?
Reduces CSF production or cerebral edema as a result of capillary membrane stabilization –> Dexamethasone and methylprednisolone
What should be done if corticosteroids are used during the pre/intra/post operative period?
Blood glucose levels need to be drawn
What questionnaire can be used to measure a patients functional capacity of the heart?
Metabolic equivalents (METs) –> 2 questions
1. Are you able to walk four blocks without stopping
2. Are you able to climb two flights of stairs without stopping
Yes to both of these indicates good functional capacity, greater than 4
What should be done if patient presents with less than 4 METs?
Further investigated to identify more cardiac risk factors and may need to cancel the case.
Stage I and II HTN classification
Stage I –> 130-139/80-89
Stage II –> Greater than 140/90
What should be done if a patient presents with uncontrolled or stage III HTN?
This is BP greater than 180/110 –> Elective surgery should be postponed until optimal BP is met
This increases the patients risk for intra operative hemodynamic instability and MI
BP controlled below which stage is not an independent risk factor for peri operative cardiovascular complications?
Stage III –> If BP is below 180/110 then the patient will be in stage II or less not independently indicating cardiac complications.
What are some of the revised cardiac risk index factors?
The lack of hemodynamic compensatory responses that occur during ________ ________ may predict absence during anesthesia and surgery.
Positional changes
Myocardial ischemia occurs when ___________
Insufficient oxygen and nutrient supply to meet the metabolic requirements of myocardial cells.
Risk factors for ischemic heart disease
Advanced age, smoking, DM, HTN, pulmonary disease, previous MI, LV wall dysfunction, and PVD
Is routine ECG testing recommended in low risk surgeries?
No
How would you classify stable angina?
Substernal discomfort brought on by exertion, relieved by rest or nitroglycerin in 15 minutes –> Unlikely to pose a greater threat peri operatively than an unaffected patient.
What type of angina is associated with the highest risk for peri operative MI?
Unstable angina –> Elective surgery is canceled until the cardiovascular status has been thoroughly evaluated and optimized.
What 3 things defines unstable angina?
- Newly developed within the past 2 months
- Angina that progressively worsens with increased frequency, intensity, or duration
- Angina which lasts longer than 30 minutes, exhibiting transient ST or T wave changes without Q waves
What two tests can be helpful in determining ischemic heart disease?
Exercise/stress ECG and coronary angiography
Re infarction rate if a patient has surgery within 30 days of an MI?
33% –> elective cases should wait at least 60 days after an MI
Two types of stents, which ones decrease restenosis rate?
Bare metal (BMS) and drug eluding (DES)
DES –> Further reduces stent thrombosis
What does the pharmacotherapy look like in a patient who just had a stent placed?
Aspirin –> Generally indefinitely
P2Y12 blocker –> Minimum of 6 months
Both of these taken together
Preserved vs reduced ejection fraction? What population sees better perioperative outcomes?
Preserved –> 50% or greater
Reduced –> 49% or less
Preserved has better outcomes…obviously
Which disease process places patients at significantly higher perioperative complication rates?
Heart failure
A physical exam on a patient showing bilateral rales or an S3 gallop, or a chest x-ray showing pulmonary vascular redistribution indicates?
Heart failure –> Left ventricular dysfunction
What are some tests that can determine LV function?
Echocardiogram, cardiac magnetic resonance, radionuclide angiography, and contrast ventriculography.
An EF of what value is associated with the greatest incidence of post operative heart failure and death?
35% or less
Most common valvular heart diseased valves?
Aortic and mitral –> May involve stenosis, incompetence, or both
Most common cause is rheumatic heart disease
Normal valves can compensate up to _______ times normal cardiac output
7
What type of stenosis places the patient at greatest risk for non-cardiac surgery?
Aortic stenosis –> If the cross sectional area of the AV valve is less than 1 cm^2, this is associated with a 14 fold increase in sudden peri operative death
What should be done for a patient showing up for elective surgery who has symptomatic aortic stenosis?
Case is postponed until after cardiac surgery consult.
When should an echocardiogram be preformed when a patient presents with valvular stenosis or regurgitation?
If moderate or severe stenosis or regurgitation is suspected. An Echo should be preformed if one hasn’t been in the past year.
What should all patients with symptomatic arrhythmias undergo prior to surgery?
Electrocardiogram, as well as potassium and magnesium levels
True or False
Benign ventricular arrhythmias carry an increased surgical risk?
False
What complications can pacemakers mask?
Anti-arrhythmic toxicity, electrolyte imbalances, and MI/irritability
What maneuver can help slow the patients HR if they are pacing over their pacemaker?
Valsalva –> Should slow patients HR so you can see the pacemaker take over with spikes
What is an indication of placing transvenous or temporary pacing wires?
Persistent bradycardia not responsive to intra-venous administration of atropine or exercise.
What should be seen if a patients intrinsic HR is below the set pacemaker rate?
Pacer spikes with rate at what pacer is set to
Who should preform direct interrogation of the pacemaker?
Qualified member of the CIED management team –> Can check battery status, lead performance, and adequacy of current settings.
What should be avoided if myopotentials are inhibiting the pacemaker?
Succinylcholine and shivering
What can you learn about the patients heart function when a stress test is preformed?
The extremes of blood pressure and heart rate the patient can tolerate while awake –> Stress testing is preferred over an ECG
What results in a stress test indicates that perioperative risk is low?
If no signs of ischemia are seen with reasonable workload (85% of predicted maximal HR)
Stress testing ________ indicated in patients with intermediate risk factors undergoing major vascular surgery.
ISN’T –> Its pre-operative value has been questioned
What is considered significant stenosis?
Occlussion of 70% or more in any artery or 50% or more in the left main coronary artery
What three things indicate poor ventricular function?
CI of less than 2.2, LVEDP of 18 mm Hg or higher, or EF of less than 40%
Wall motion abnormalities seen in an EEG?
Hypokinesia –> Reduced movement
Akinesia –> No movement
Dyskinesia –> Paradoxical movement
What effect do statins have on the body?
Lipid lowering, enhancing endothelial function, improving atherosclerotic plaque stability, decreasing oxidative stress, and reducing vascular inflammation.
What effect do beta blockers have on the body?
Restores oxygen supply and demand mismatch, reduced peri operative ischemia, redistributes coronary blood flow to the subendocardium, stabilizes plaques, and increases v-fib thereshold
Should beta blockers be used routinely?
No –> Low risk patients or patients having non-cardiac surgery has been associated with increased rates of mortality and morbidity from bradycardia, hypotension, and stroke.
Patients having 2 risks factors or more for various heart problems should be treated with what two drug classes?
Beta blockers and statins
What type of heart dysfunction warrants ACE-Inhibitors?
Stable left ventricular dysfunction
What types of medications should be given to patients with a history of –> A-fib, DVT, PE, and sometimes prosthetic heart valves?
Factor Xa inhibitors and thrombin inhibitors
What is a CHADS score used to determine?
Cessation of anticoagulants in patients with a-fib
When should anti coagulants be resumed after surgery?
24-48 hours if surgical bleeding is controlled.
At what PaCO2 should surgery be cancelled?
50 mmHg or higher
Two forms of COPD
Emphysema and chronic bronchitis
What should be done if a patient presents with thick, purulent sputum and pulmonary infiltrates on chest x-ray?
Specific antibiotic therapy is initiated
Should prophylactic antibiotics be used to sterilize sputum?
No –> secondary resistant infections may develop
What is the most reliable way to reduce the incidence of pulmonary complications?
Have the patient stop smoking cigarettes if they smoke
How many weeks of non-smoking will the smoker have pulmonary complication rates during surgery similar to a non-smoker?
8 weeks
What form of COPD can be seen on a chest radiograph? What can’t in most cases?
Emphysema can –> Diaphragmatic flattening and vertical orientation of the cardiac silhouette
Chronic bronchitis can’t in most cases
What is the hallmark sign of asthma?
Inflammation of the airways –> reversible airway obstruction
What are some precipitating factors of asthma?
Allergens, exercise, URIs, emotional stressors, and unidentified triggers
An asthmatic is coughing persistently during your preoperative assessment, what should be done?
Reschedule for another day –> Also if they present with dyspnea, wheezing, and tachypnea
What are normal spirometry values?
80-100% of baseline –> This evaluates peak expiratory rate in asthmatics
What medication should be taken the morning of surgery in an asthmatic?
Beta adrenergic metered dose inhaler –> Should be taken into the OR with the patient as well.
What are therapeutic serum theophylline level?
10-20 mcg/mL
What non-pharmacologic method should be done prior to surgery in an asthmatic patient?
Adequate hydration to reduce airway desiccation and improve mobilization of secretions.
Children should wait _______ weeks after a URI to prevent anesthesia related complications
6 –> They will present with heightened airway irritability until this point.
Can children with uncomplicated URI undergo anesthesia?
Yes, doesn’t significantly increase complications as long as it is an uncomplicated infection.
Active GI bleeding requires what preoperative lab values?
H&H –> Hematocrit may be falsely elevated due to hemoconcentration
True or False
Considerable damage to the liver may be evident before lab tests are altered?
True
What should be suspected in cases of unexplained jaundice or elevated transaminase levels?
Hepatobiliary dysfunction –> Elective surgery should be avoided due to hepatic failure being associated with a higher risk of morbidity and mortality
What may be required for correction of preoperative coagulopathy?
Phytonadione AND FFP and cryo
What medications should be avoided in a patient with hepatic encephalopathy?
Sedative –> Because they may already be disoriented and somnolent
Also need to check sugars as this population is at risk for rapid development of hypoglycemia
What blood level is more specific of liver damage if your liver enzymes are elevated? (AST/ALT)
LDH –> Lactate dehydrogenase
What is the most reliable and rapid test done to diagnose acute parenchymal injury? (liver dysfunction)
Elevated prothrombin time –> It reflects the inability of the acutely damaged liver to synthesize clotting factors.
Hypoalbuminemia will also be apparent, but albumin has a longer half life than prothrombin thus showing increased prothrombin time first.
What are some hepatotoxic drugs that should be discontinued prior to surgery in a patient with liver dysfunction?
Acetaminophen, NSAIDS, aspirin, methyldopa, isoniazid, and rifampin
What scoring system was developed to predict surgical mortality in patients with cirrhosis?
Child-Pugh score –> Class A (10% mortality), Class B (30% mortality), and Class C (80% mortality)
Class A and B are suitable for surgery, Class C is treated medically (surgery is delayed until liver function improves)
What would be suspected in a patient with urinary retention or neurogenic bladder due to spinal cord injury or long standing DM?
Chronic UTIs –> This is due to frequent cauterizations
This should be ruled out (infection) before elective surgeries are preformed! Especially before mitral valve replacement/joint replacements (hips)
What generally has to occur prior to apparent renal insufficiency?
70% of nephrons become non-functional
What lab levels correlate more with GFR?
Creatinine –> BUN DOES NOT
Creatinine should be 0.5 - 1.5 mg/dL normally
What patient population may have higher than normal creatinine levels?
Muscular patients
What patient population may have normal creatinine levels but still may have a decline in GFR?
Elderly patients –> This is due to the decreased muscle mass of these patients and creatinine is a byproduct of skeletal muscle metabolism.
What is the most commonly used endogenous marker of renal reserve or GFR?
Creatinine clearance
Creatinine clearance formula
Usually done via a 24 hour collection period.
What GFR rate/creatinine clearance signifies renal failure?
Levels less than 10 mL/min
Distinguishing features between DM I and DM II?
What is the goal of dialysis therapy?
Maintain a reasonable degree of homeostasis, although creatinine and BUN levels may remain abnormal
How are estimates of volume status measured in dialysis dependent patients?
Weight gain from previous dialysis treatment
What lab value should be measured prior to surgery in a dialysis dependent patient?
K –> This should be done within 6-8 hours of surgery regardless of when last dialysis session was.
In cases of K levels above 5.5 and congestive heart failure, surgery should be delayed until after dialysis
What abnormal blood levels are suspected in a patient with chronic renal failure?
Low Hgb –> Chronic anemia, this is due to a decreased production of erythropoietin
May need blood prior to surgery –> Greater risk of being infected with hepatitis, HIV, or both due to the increased need for blood and immunosuppressive therapy in chronic renal failure.
What coagulopathic processes are suspected in a patient with renal failure?
Decrease in platelet adhesiveness due to the chronic state of metabolic acidosis
Which sedative medication should be avoided in renal patients due to its prolonged effects?
Diazepam –> Sedative medications should be given at lower than normal doses
What should be considered when taking a NIBP on a renal patient?
If they have an AV shunt –> If yes, assess for patency and signs of infection, do not take NIBP on the extremity with the shunt
A DM II patient can generally benefit from ___________
Diet modification, exercise, and weight control alone opposed to starting medications like metformin immediately
What is death in a majority of patients with DM generally due to?
Secondary to atherosclerosis –> MI, stroke…
What airway concerns can a diabetic patient present with?
Stiff joint syndrome due to glycosylation –> This causes limited mobility of the upper cervical spine (poor view on DL and difficult TI)
Normal hemoglobin A1C values
Normal –> Less than 5.7%
High risk –> 5.7% - 6.4%
Diabetes –> 6.5% and higher
What tests besides glucose levels are generally performed on diabetics prior to surgery?
Stress test or 12 lead prior to surgery, this population is at an increased risk of peri operative myocardial ischemia
What insulin agent is short acting? What route can it be given?
Regular insulin, IV or subcutaneous
How should glucose levels be maintained during surgery?
Less than 180 mg/dL while preventing hypoglycemia
Why should diabetics have surgery earlier in the day?
Minimize their fasting period
What should be done in diabetic patients who are fasting prior to surgery, and they took insulin?
Should have a crystalloid solution of 5% glucose incase it is needed during surgery to maintain optimal levels
When should a patient who is fasting take a short-acting insulin bolus (regular insulin) prior to surgery?
Only if their glucose level is above 200 mg/dL AND more than a 3 hour long procedure.
How should DM I be treated with insulin prior to surgery?
Give them 50% of their normal dose (intermediate or long acting) prior to surgery and then start a continuous 5% glucose infusion peri operatively
What should be done in a patient with DM I who needs to be placed prone for surgery?
Their insulin pump should be relocated or padded
What should be optimized prior to surgery in a patient presenting with Graves disease
Reaching a euthyroid state
What drugs should be continued peri operativley in a patient with graves disease?
All drugs for the disease (Methimazole, propranolol)
What drug may a patient with graves disease require higher doses of pre operatively? What drug should be avoided?
Higher doses of anxiolytics and sedatives such as benzodiazepines
Avoid anti-cholinergic drugs as these interfere with heat regulating mechanisms and can potentiate tachyarrhythmias
Do patients with hypothyroidism need to have thyroid levels stabilized prior to surgery?
Not necessarily –> No difference in outcomes has been reported in patients untreated and patients with normal thyroid levels
Cushing disease symptoms
Due to over active adrenal gland making too much glucocorticoid hormones –> HTN, hypovolemia, truncal obesity, buffalo hump, abdominal and gluteal striae, plethoric facial appearance (moon facies)…
Addison disease symptoms
Due to under active adrenal gland –> skin hyperpigmentation, weight loss, muscle wasting, hypotension, intravascular volume depletion…
What patients are at risk for depression of HPA (hypothalamic-pituitary-adrenal) axis perioperatively?
- Received 20 mg of more of prednisone or equivalent for 5 or more days
- Been treated for more than a month
What test can be drawn to assess adrenocortical function?
ACTH stimulation test –> Can evaluate the need for supplemental steroid therapy.
Patients receiving high does steroid therapy (Addison’s disease) may need further supplementation prior to surgery (higher than normal doses) due to surgical stress
What could present in a patient who is requiring high dose steroid therapy or a patient at risk for HPA suppression who doesn’t receive steroids pre operatively?
Unexplained hypotension in spite of IV fluids or cardiovascular collapse.
Why have we gone away from routine lab testing on all patients regardless of indications?
Because it isn’t cost effective and predictive of post operative complications, AND the likelihood of finding an anomaly is very small
What can false positive routine lab results cause a patient to do?
Leads the patient to additional follow up lab results which can place the patient at risk for increased morbidity.
In general, diagnostic testing is considered current if its within _____________ of the procedure.
6 months –> besides electrolyte levels like K in a patient receiving digitalis or diuretics, this should be obtained within 7 days of surgery
ECG are considered current if one was taken within __________ of the elective procedure in a patient with a stable heart disease
30 days
Should all women of child bearing age receive a pregnancy test prior to surgery?
This remains controversial –> Patient should be offered one (HCG) if you suspect this. If the patient refuses they should be educated on fetal risks and required to sign informed consent so the provider isn’t held liable
Pregnant patients should be advised to postpone the surgery until _____________
Postpartum or well after the first trimester when fetal organogenesis is complete
Chest radiographs are generally not indicated because they aren’t _______________
Cost effective –> really only routinely used if they patient is greater than 75 years old
For routine ECG testing, which patient population would get one pre operatively?
Patients 65 years and older and is considered current in the routine population if it is within 1 year of surgery.
Patients with stable heart diseases are considered current if it is within 30 days of the procedure.
Preoperative ingestion of a carbohydrate supplement up to 2 hours before surgery has been associated with what?
Shorter hospital stay, faster return of bowel function, and less muscle mass loss
Why have traditional fasting guidelines been becoming more liberal?
Fasting after midnight fails to address –>
1. Time of surgery
2. Time patient went bed
3. Variability in gastric emptying
How small must food be to pass through the stomach, into the small intestine? Liquid?
Food must be less than 2 mm in size to pass through the pylorus.
Liquid takes 1-2 hours to empty into the pylorus
What has been noticed in patients since fasting times have been minimized?
Patients are less irritable, less thirsty, less hungry, have fewer headaches, are more comfortable, and tolerate the pre operative phase better.
Drinking modest amounts of liquids 2-3 hours pre operatively has been shown to do what?
Lower residual gastric volume and increase gastric pH (more basic)
Does chewing gum or sucking on candy warrant cancellation?
No, but these should be avoided once fasting from clear liquids has commenced.
What are some conditions that increase the risk of regurgitation and pulmonary aspiration during anesthesia?
What are the fasting guidelines in healthy patients undergoing surgery?
What should you do if you feel like your patient is at risk for gastric aspiration despite an adequate fasting period?
Use of gastric stimulants, blockade of gastric acid secretion, antiemetics, or a combo of these.
What is the purpose of the ASA classification?
Strictly a standardized way to present the physical status of the patients pre operative health and NOT an indicator or anesthesia risk
How would you classify a patient who presents with a severe systemic disease?
ASA III
How would you classify a patient with a mild systemic disease who needs an emergent surgery?
ASA IIE
What are some limitations to the ASA classification scale?
Can’t account for every patients true status, also patients may be over classified if the hospital uses this system for statistical or reimbursement purposes
What is the universal protocol?
Joint commission endorsed which aims to prevent wrong site, wrong patient, wrong surgery procedure.
What are the guidelines for the universal protocol?
Conduct a pre procedure verification process, mark the procedure site, perform a time out
