2009 with explanations (2009_day2_grdhg) Flashcards
- Guy with NG, output is 1500 cc/day. He becomes lethargic and weak, and has ileus. What is most likely?
a. hypomagnesemia
b. hypochloremic metabolic alkalosis
c. hypokalemic metabolic alkalosis
d. hyponatremia
Answer: C (NG loss lead to hypokalemia which lead to chloride resistant shift of hydrogen ions into intracellular space leading to metabolic alkalosis, Hypokalemia also leads to weakness and ileus)
Metabolic alkalosis
Causes
There are five main causes of metabolic alkalosis
These can be divided into two categories, depending upon urine chloride levels.
Chloride-responsive (20 mEq/L)
· Retention of bicarbonate
· Shift of hydrogen ions into intracellular space - Seen in hypokalemia. Due to a low extracellular potassium concentration, potassium shifts out of the cells. In order to maintain electrical neutrality, hydrogen shifts into the cells, raising blood pH.
· Alkalotic agents - Alkalotic agents, such as bicarbonate (administrated in cases of peptic ulcer or hyperacidity) or antacids, administered in excess can lead to an alkalosis.
·
HYPOKALEMIA
· Mild hypokalemia is often without symptoms, although it may cause a small elevation of blood pressure,[2] and can occasionally provoke cardiac arrhythmias.
· Moderate hypokalemia, with serum potassium concentrations of 2.5-3 mEq/L, may cause muscular weakness, myalgia, and muscle cramps (owing to disturbed function of the skeletal muscles), and constipation (from disturbed function of smooth muscles).
· Severe hypokalemia, flaccid paralysis, hyporeflexia, and tetany may result. There are reports of rhabdomyolysis occurring with profound hypokalemia with serum potassium levels less than 2 mEq/L. Respiratory depression from severe impairment of skeletal muscle function is found in many patients.
· Some electrocardiographic (ECG) findings associated with hypokalemia are flattened or inverted T waves, a U wave, and prolongation of the QT interval. The prolonged QT interval
CAUSES
Hypokalemia can result from one or more of the following medical conditions:
1. Inadequate potassium intake
2. Gastrointestinal/integument loss
o A more common cause is excessive loss of potassium, often associated with heavy fluid losses that “flush” potassium out of the body. Typically, this is a consequence of diarrhea, excessive perspiration, or losses associated with surgical procedures. (by extrapolation NG losses)
o Vomiting can also cause hypokalemia, although not much potassium is lost from the vomitus. Rather, there are heavy urinary losses of K+ in the setting of post-emetic bicarbonaturia that force urinary potassium excretion (see Alkalosis below).
3. Urinary loss
4. Distribution away from ECF
- Low magnesium, which is a sign?
a. absent DTRs
b. tremor
c. hypotension (no)
d. bradycardia
Answer: B
Deficiency of magnesium causes weakness, muscle cramps, cardiac arrhythmia, increased irritability of the nervous system with tremors, athetosis, jerking, nystagmus and an extensor plantar reflex. In addition, there may be confusion, disorientation, hallucinations, depression, epileptic fits, hypertension, tachycardia and tetany.
- Patient with carpal tunnel syndrome, which are you most likely to find?
a. weak thumb abduction
b. weak thumb adduction
c. weak PIP flexion in all fingers
d. hypothenar atrophy
Answer: A
Compression of the median nerve as it runs deep to the transverse carpal ligament (TCL) causes wasting of the thenar eminence, weakness of the flexor pollicis brevis, opponens pollicis, abductor pollicis brevis, as well as sensory loss in the distribution of the median nerve distal to the transverse carpal ligament. There is a superficial sensory branch of the median nerve, which branches proximal to the TCL and travels superficial to it. This branch is therefore spared, and it innervates the palm towards the thumb.
In chronic cases, there may be wasting of the thenar muscles, weakness of palmar abduction of the thumb (difficulty bringing the thumb away from the hand).
- Patient with mediastinitis (picture provided, large wound) post CABG. What is the best management?
a. Debridement, rigid sternal fixation, delayed primary closure
b. Debridement and secondary closure
c. Debridement, local myocutaneous flap
d. Debridement, rigid sternal fixation, myocutaneous flap
Answer: C
Derek says A – according to Journal of Cardio thoracic sx - modern management of mediastinitis with early aggressive debridement followed by delayed wound closure has been reported to reduce early mortality to less than 20%.
Surgical debridement is the mainstay of therapy for postoperative mediastinitis. Debridement may be followed by a short or long period of open packing, immediate closure of the debrided sternum with or without closed-wound irrigation, or resection of the sternum with primary or secondary closure of the wound using muscle or omental flaps
- Shown picture of a child with burn to right thorax and right arm. Erythematous. What is the degree of burn?
a. First degree
b. Second degree
c. Third degree
d. Mixed second and third
Answer: B vs. C (I recall seeing whitish areas over the erythema- the erythema + blisters = 2nd degree burn, but the whitish skin = 3rd degree burn)
6. Shown picture of a large keloid on earlobe. What is the management? a. Surgical excision and careful closure b. Surgical excision and radiation c. Compressive dressings d. Intralesional steroid injection
Answer: B
Derek says – D – this is what we routinely did on plastics
Most studies [18,29-31], but not all [32], have found radiation therapy to be highly effective in reducing keloid recurrence, with improvement rates of 70 to 90 percent when administered after surgical excision.
https://webvpn.mcgill.ca/http/www.utdonline.com/online/content/topic.do?topicKey=dermatol/7243&selectedTitle=1%7E39&source=search_result#H6
An auricular keloid occurring following ear-piercing remains a difficult condition to treat. Various treatments have been described, with different reported degrees of success. Pressure therapy has been shown to be an effective treatment for auricular keloids, although the devices used have not all been universally accepted. We assessed 30 patients, between 1989 and 1999, who had been fitted with pressure devices made from Zimmer splints. There was a 50% or greater reduction in the size of each keloid when assessed at 1 year
- Shown picture of an ulcer on the sole of a diabetic foot. What is the mechanism by which this occurs?
a. vasculopathy
b. neurophaty
Answer: B
Neuropathy is present in over 80 percent of patients with foot ulcers; it promotes ulcer formation by decreasing pain sensation and perception of pressure, by causing muscle imbalance that can lead to anatomic deformities, and by impairing the microcirculation and the integrity of the skin. Once ulcers form, healing may be delayed or difficult to achieve, particularly if infection penetrates to deep tissues and bone and/or there is diminished
- Shown picture of venous stasis ulcer, which is best management?
a. compressive dressings
b. revascularization
c. sulfadiazine lotion
Answer: A (compressive is for prevention of ulcers and of recurrence; occlusive dressings are a treatment option of venous ulcers)
Occlusive dressings may be fully occlusive (impermeable to gases and fluids) or semi-permeable (impermeable to fluids and partially permeable to gases like oxygen and water vapor). Occlusive dressings speed reepithelialization, stimulate collagen synthesis, and create a hypoxic environment at the wound bed that encourages angiogenesis [92]. Infection rates with occlusive dressings are lower than the rate of infection in general wound care. This may be due to several factors including effective barrier protection and reducing local pH [93]. Up to date
The continued use of graduated compression stockings after ulcer healing reduces recurrence and patients. Up to date
- Shown picture of TRAM to right breast POD#2. Upper part of flap is good cap refill, good pulse by Doppler, and warm. Picture shows upper part is normal color, but lower looks venous congested and has small bullae. What is the best management?
a. Observe
b. Heparinize
c. leeches
d. urgent exploration
Answer: C
Salvage Procedures for the Failing Flap
Monitoring the free flap during the postoperative phase is critical to ensure flap survival. When recognized early and managed promptly (
- Shown a picture of mole on face. You do not feel that you can excise the lesion and do primary closure. What is the best management?
a. FNA
b. Incisional biopsy of the mole
c. Incisional biopsy of the mole and normal skin
d. Shave biopsy of entire lesion
Answer: C
Derek says – B – according to Shwartz – under melanoma treatment – All suspicious lesions should undergo excisional biopsy. A 1 mm margin of normal skin is taken if the wound can be closed primarily. If removal of the entire lesion creates too large a defect, then an incisional biopsy of a representative part is recommended.
· Simple excisional biopsy is the procedure of choice for removal and diagnosis of a melanocytic nevus. All removed melanocytic nevi should be submitted for microscopic evaluation. It is optimal to strive for complete excision of a given lesion, if at all possible, when melanoma is considered in the differential diagnosis.
· A complete excisional biopsy permits all available histopathological criteria to be applied to a lesion and thus enables a more precise diagnosis.
· When a partial punch or shave biopsy sample is taken from a lesion, the interpreting pathologist cannot apply important criteria, such as symmetry and circumscription (lateral demarcation), to the assessment of the lesion. If a partial biopsy specimen of a larger lesion is obtained because of clinical necessity, the fact that the specimen is partial should be clearly indicated on the requisition form.
· Partial biopsy samples can sometimes lead to misdiagnosis because of sampling error.
· Partial biopsy samples can inflate the number of procedures required for diagnosis because a partial biopsy sample that does not enable a definitive diagnosis to be made necessarily leads to subsequent reexcision of the lesion in question.
http://emedicine.medscape.com/article/1058445-diagnosis
- Shown picture of big ulcerated lesion over lower leg. Patient had tibia fracture 20 years ago with chronic draining sinus, which has been enlarging for past few months. What is most likely?
a. Superinfection
b. SCC
c. Osteosarcoma
d. Something else
Answer: B
Squamous cell carcinoma (SCC) is a rare, but well-documented complication of osteomyelitis and chronic wounds. Treatment of choice for these tumors commonly occurring on the legs has been amputation. Two recent articles have suggested the utility of Mohs micrographic surgery (MMS) as a limb saving procedure.
OBJECTIVE:
- What is the deepest burn that you can get for spontaneous epithelialization to still occur?
a. epithelium
b. superficial papillary dermis
c. deep papillary dermis
d. reticular layer
2nd Reticular layer + Third degree burn = no epithelization
BURN CLASSIFICATION
Degree Description
1st Sunburn (epidermis)
2nd Superficial Dermis (Papillary) Painful to touch; blebs and blisters; hair follicle intact; blanches
2nd Deep Dermis (Reticular) Decreased sensation; loss of hair follicles (need skin grafts)
3rd Leathery feeling (charred parchment); down to subcutaneous fat
4th Down to bone, into adjacent adipose or muscle tissue
- Shown picture of carpal tunnel release intraop, with 2 longitudinal lines that are thin and look like veins. What is the etiology?
a. Congenital
b. Systemic disease
c. Inflammation
d. Factitious
A???
- Shown picture of electrical burn to right hand and arm, no eschar. Patient has extreme pain on passive stretch of fingers. What do you do?
a. Immediate escharotomy hand and arm
b. Immediate fasciotomy
c. Cloxacillin
Answer: B
Pain on passive stretch of fingers = CLASSIC SIGN FOR COMPARTMENT SYNDROME = urgent fasciotomy
ESCHAROTOMY INDICATIONS (perform within 4-6 hours)
1. Circumferential burns
2. Low temperature; weak pulse; capillary refill; pain sensation; and neurologic function in extremity → may need fasciotomy if compartment syndrome suspected
3. Problems ventilating patient with significant chest torso burns
- Shown picture of kid with dog bite to face. What is the best management?
a. Irrigate, debride, and careful multiple layer closure
b. Irrigate, debride, and healing by secondary intention
c. Irrigate, debride, and primary closure 3 days later
d. Irrigate, debride, and careful one-layer closure
Answer: D
I was bitten by pittbull in face (age= 16), Chief of Plastic Surgery at Sunnybrook Hospital (Major trauma hospital) in Toronto treated me with tetanus shot, irrigation, debridement, one layer closure with nylon sutures…. source: life experience
- Resident appointed chief at some hospital where he has never been. On arrival, he introduces himself to head nurse and familiarizes himself with hospital procedures and stuff. What CanMEDs role is he demonstrating?
a. Collaborator
b. Communicator
c. Professional
d. Manager
Answer: D ?
Different elements of CANMEDS role can be applied here ie: collaborator, communicator but I think manager fits the best see table below
Manager · utilize resources effectively to balance patient care, learning needs, and outside activities
· allocate finite health care resources wisely
· work effectively in a health care organization
· utilize information technology to optimize patient care, life-long learning and other activities
- Senior resident never respects gowning and hand-washing procedure during an MRSA outbreak. What CanMEDs competency is he failing to show?
a. Health advocate
b. Professional
Answer: A (see table)
Health Advocate · identify the important determinants of health affecting patients
· contribute effectively to improved health of patients and communities
· recognize and respond to those issues where advocacy is appropriate
- Anion that is not measured and contributes to your normal anion gap?
a. lactate
b. urea
c. potassium
d. albumin
D
In normal subjects, the AG is primarily determined by the negative charges on the plasma proteins, particularly albumin.
-negatively charged proteins account for about 10% of plasma anions and make up the majority of the unmeasured anion represented by the anion gap under normal circumstances.
Potassium is also not usually measured but contributes to the anion gap. However, it is a CATION and the questions asks specifically for an anion
- What gives you decreased platelet count and qualitative defect in platelet function?
a. Bernard-Soulier - deficiency of platelet glycoprotein protein Ib, which mediates the initial interaction of platelets to the subendothelial components via the von Willebrand protein. It is a rare but severe bleeding disorder. Platelets do not aggregate to ristocetin. The platelet count is low, but, characteristically, the platelets are large
b. vWD – not typically thrombocytopenic
c. Liver failure
d. Uremia - Bleeding time is generally very prolonged in patients with uremia, signifying a major defect in platelet function, which improves after dialysis.
Answer: A
- 15 year-old guys shows up with retracted testicle, absent cremasteric reflex, 6 hours post start of pain. Best management?
a. Insert a foley
b. Give antibiotics
c. Go to OR urgently for detorsion of left testicle and left orchiopexy
d. Go to OR urgently for detorsion of left testicle and bilateral orchiopexy.
**Do not delay surgery for diagnostic procedures
Answer: D
Testicular Torsion – Shwartz
- At time of surgery, orchipexy should be preformed by fixing the testicle to the scrotal wall at three different points. The anatomic predisposition to torsion affects both sides, therefore, the contralateral testicle shoulde be similarily repaired.
- Shown an axial slice of CT showing right SC joint dislocation, with head of clavicle displaced posteriorly. There is no pneumo at the lung apices. Patient has distended neck veins, plethora in the face, and complains of respiratory distress. What is the best management?
a. Endotracheal intubation
b. Cric
c. SC joint reduction
d. Chest decompression with chest tube
Answer: C
- Woman with medullary thyroid cancer, has 12 and 15 year old child. What is most appropriate screening test for her children?
a. Ret
b. P53
c. CT scan
d. Other wrong answers
Answer: A
· Medullary thyroid cancer (MTC) is a neuroendocrine tumor of the parafollicular or C cells of the thyroid gland; it accounts for approximately 3 to 5 percent of thyroid carcinomas. A characteristic feature of this tumor is the production of calcitonin. Most cases are sporadic. (See ‘Clinical presentation’ above.)
· The most common presentation of sporadic MTC (in 75 to 95 percent of patients) is a solitary thyroid nodule. In most patients, the disease has already metastasized at the time of diagnosis. (See ‘Clinical presentation’ above.)
· Some patients with apparently sporadic MTC have unsuspected germline RET mutations (the underlying defect in MEN2) and, therefore, heritable disease. We agree with the 2009 American Thyroid Association Guidelines for Management of Medullary Thyroid Cancer that all patients with C cell hyperplasia or MTC be offered germline RET testing. (See ‘Genetic screening in sporadic MTC’ above.)
· Given the possibility that any patient with MTC may have MEN2, preoperative testing must also include measurement of serum calcium (to rule out hyperparathyroidism requiring concomitant surgical intervention) and testing for pheochromocytoma. We suggest plasma fractionated metanephrines as the initial screen for pheochromocytoma. (See ‘Testing for coexisting tumors’ above.)
- Guy post MVC, presents with tachypnea, tachycardia, decreased air entry on one side, hyperresonant percussion, and trachea deviated to contra-lateral side. What do you do?
a. Portable CXR to confirm suspicion - NO
b. Chest tube in 6th ICS, mid axillary line – Yes, but first…
c. Needle decompression 2nd ICS mid clavicular line
d. Urgent thoracotomy – Only if you’re a crazy emerge cowboy…NO
Answer: C
- Which of the following is not an absolute indication to a chest tube?
a. Spontaneous pneumo
b. Open pneumo
c. Chylothorax
d. s/p thoracic surgery for drainage
A
- Patient comes in with trauma, needs blood. His blood is checked for ABO and Rh compatibility, but not cross-matched. What is the chance that he will get an acute hemolytic reaction?
a. 0.1%
b. 1%
c. 5%
d. 10%
Acc to question 17 2007 answer is 10%
Answer: A vs. B
- Which of the following is not a feature of acute rejection in kidney transplant.
a. Hypertension – kidney not functioning
b. pancytonia
c. tenderness at graft - yes
d. increased graft size - yes
Answer: B
CLINICAL MANIFESTATIONS — Patients with acute renal allograft rejection present with an acute rise in the serum creatinine, which suggests underlying renal allograft dysfunction. A rising serum creatinine level, however, is a relatively late development in the course of a rejection episode and usually indicates the presence of significant histological damage. Some additional clinical manifestations include decreased urine output, increased blood pressure, pyuria, and/or new or worsening proteinuria.
Many patients who have acute rejection episodes are asymptomatic. Fever, graft pain and/or tenderness, and graft swelling are currently uncommon with modern immunosuppressive drug therapy unless immunosuppression is completely discontinued.
- Regarding acute rejection in transplant, all true except?
a. Cell mediated
b. Most common rejection reaction
c. Most are asymptomatic
d. Biospy shows intravascular coagulation
ANSWER: D
a. Cell mediated- TRUE
b. Most common rejection reaction – USED TO BE, BUT NOW CHRONIC
c. Most are asymptomatic -
d. Biospy shows intravascular coagulation – Bx of acute reaction shows: - cellulat infiltrate, membrane damage, and apoptosis of graft cells v.s……HYPERACUTE- shows intravascular coagulation
- Which of the following causes reversible nephrotoxicity?
a. Cyclophosphamide
b. Azathioprine
c. Cyclosporin A
d. Steroids
C
Patients treated with the calcineurin inhibitors cyclosporine and tacrolimus are at high risk of developing renal injury [1]. Calcineurin inhibitor nephrotoxicity (CIN) is manifested both as acute azotemia which is largely reversible after reducing the dose, or as chronic progressive renal disease which is usually irreversible [2-5]. Other renal effects of the calcineurin inhibitors include tubular dysfunction, and rarely a hemolytic uremic syndrome (HUS) that can lead to acute graft loss [2]. A similar pattern of renal injury from cyclosporine is seen with the use of tacrolimus, thereby suggesting a drug class effect.
- In heart transplant, all are used except?
a. methotrexate
b. tacrolimus
c. azathioprine
A
- Guy post multiple trauma, in ICU. Has pH 7.38, PCO2 of 30, bicarb of 20. What is most likely?
a. respiratory alkalosis, compensated
b. respiratory alkalosis and metabolic acidosis
c. some other ridiculous answers
Review ABGs
- Patient with pH 7.55, pCO2 24, PO2 60 on 30% O2. He is on respirator at RR 12 and tidal volume 10cc/kg, PEEP 5. What is the first step?
a. increase FiO2
b. increase tidal volume
c. increase dead space of tubing
d. sedate patient more
Answer: A
- Which of the following is the most common mechanism of hypoxia in acute lung injury?
a. diffusion problem
b. right to left shunt
c. ventilation perfusion mismatch
d. something else
Answer: A vs. B?? they do not tell you what type of lung injury
- What is the rate of transmission of HCV from a single unit PRBC transfusion?
a. 1/30
b. 1/300
c. 1/300,000
d. 1/3,000,000
Answer: D
HCV: 1:1,000,000
HBV: 1:30-250,000
HIV: 1:400,000 to 1:2,400,000
- What is not a criteria for SIRS?
a. respiratory rate > 20
b. temp > 38.5
c. HR
C
Systemic inflammatory response syndrome (SIRS) — SIRS refers to the consequences of a dysregulated host inflammatory response. It is clinically recognized by the presence of two or more of the following (table 1):
SIRS Criteria (≥ 2 meets SIRS definition):
Temp >38°C (100.4°F) or 90
Respiratory Rate > 20 or PaCO2 12,000/mm>3, 3, or > 10% bands
- Which is not consistent with severe PE?
a. increased CVP
b. increased wedge pressure
c. decrease in PaCO2
d. increase in A-a gradient
Answer: B
A severe PE will cause increased CVP. Will get hypocapnia on the blood gas. With a PE will get an increased in the A-a gradient
- What is a contraindication to tPA?
a. Surgery 10 days ago
b. Old stroke on CT
c. Failure of urokinase
A
Contra-indications for tPA as per Schwartz:
1) Intracranial hemorrhage, major surgery within the previous 2 weeks, GI or genitourinary hemorrhage in the previous 3 weeks, platelet count less than 100,000/μL, and systolic blood pressure >185 mmHg are among the contraindications to tPA therapy
- Patient with pmhx of dvt, gets into MVC. Fracture L femur and R medial malleolus. Cerebral edema on MRI, rest of scans normal. What is the best way to anticoagulate?
a. SCDs
b. Unfractionated heparin q12h
c. LMWH
d. Warfarin
Answer: C
No contraindication to use LMWH in this patient. LMWH has been shown to be superior to the other options.
- What determines dBP?
a. peripheral vascular resistance
b. cardiac output
c. blood volume
Answer:A
- Lady with breast ca, getting intramedullary nail of femur for impending fracture. Anesthetist alerts you that she has become hypotensive, tachypneic, and difficult to ventilate. What is the diagnosis?
a. Acute PE
b. Fat embolus
c. MI
d. Anaphylaxis
Answer: B
Fat emboli are characterized by petechia, hypoxia, and confusion. Occur most common with long bone fractures.
- Guy with open fracture of tibia, loss of anterior coverage of 6 cm. What is the best option for coverage?
a. Primary closure
b. Rotational flap
c. medial gastroc flap
d. free tissue transfer
Answer: C
