The following case is meant to simulate an oral examination question. Information will be presented, and the candidate asked to discuss the situation or answer specific questions. The information will be presented sequentially. This is not intended to be a comprehensive topic review, rather it is meant to examine specific candidate competencies. If you are preparing for an oral exam consider having a friend give you this question.
You are the emergency physician in a large urban hospital. Your next patient is a 76 year old man with abdominal pain. He says that the pain began 4 hours ago and is severe and generalized over his entire abdomen. He tells you that the pain is probably due to a ‘bad sandwich’ he ate at lunch about an hour prior to onset. The onset of pain was sudden and he had one episode of diarrhea 20 minutes after the pain began, and he was also nauseous but vomited 3 times. Currently he says the pain is unbearable, and that he continues to be nauseous and dizzy, he is rolling around the stretcher and it is difficult to get him to answer questions. He denies chest pain or shortness of breath.
His wife tells you that his past medical history includes a stroke with no residual deficit, hypertension, hyperlipidemia and a remote appendectomy. His medications include hydrochlorothiazide, digoxin, simvastatin, and ASA.
The candidate may continue to try to take history but nothing further will be forthcoming. The patient will emphasize the severity of his pain in response to any questions.
Physical examination reveals the following: An obese man who appears his stated age. HR 105, BP 100/60, RR 20, O2 98% room air, temperature 37C. HEENT, , skin, neurological and respiratory exams are normal if asked for. Cardiovascular exam reveals an irregularly irregular rhythm and is otherwise normal. Abdominal exam reveals diffuse tenderness with no guarding, no rebound, and bowel sounds are inaudible. There are no palpable masses. Pulses are present and symmetrical in 4 limbs if asked for.
Bedside ultrasound is unreadable due to bowel gas if asked for.
The candidate should recognize that the patient has unstable vital signs and a potentially serious medical condition and commence intervention concurrently with further work-up. Appropriate initial steps include intravenous access, O2, monitors, airway equipment to the bedside. A fluid bolus/challenge is appropriate. Pain medication in titrated aliquots is appropriate. Additional investigations will be ordered by the candidate.
The patients nurse obtains an ECG for the patient and hands it to you.
The candidate should demonstrate competence in reading the ECG. The ECG shown demonstrates atrial fibrillation with rapid ventricular response. The rate varies between 100 and 150 bpm. There are no ischemic changes.
You reassess the patient following a 1 litre fluid bolus and intravenous narcotic pain medication. His vitals are now HR 110, BP 95/60, RR 22, O2 98% 5lpm O2, temp 37C. The physical examination is unchanged. The patient tells you his pain is unchanged.
The following labs return: WBC 18,000, Hb 125, Plt 450. AST 20, ALT, 20, Lipase 20 (normal), Bili 25 (mild elevation), lactate 2.8. Electrolytes, glucose, BUN, Creatinine and coagulation studies are all normal. An abdominal plain film is unremarkable.
The candidate should provide a differential diagnosis with a focus on high risk conditions; mesenteric ischemia/infarction, cholangitis, cholecystitis, perforated viscous, appendicitis, aortic aneurysm/dissection and other vascular catastrophe (eg. other arterial aneurysms).
The candidate should recognize that the patient is unstable and deteriorating. Additional imaging should be discussed, abdominal CT scan, CT-angiography, or percutaneous angiography. The candidate should request a surgical consultation.
- Arterial embolism: 1/3 of cases, embolism is usually from a cardiac source, and usually affects SMA (superior mesenteric artery).
- Arterial thrombosis: 1/3 of cases, atherosclerotic disease of mesenteric arteries with acute plaque rupture, may be preceded by symptoms of intestinal angina.
- Non-occlusive mesenteric ischemia (NOMI): 1/3 of cases, due to prolonged vasoconstriction or low output states (e.g. severe CHF). Dialysis, CHF, digoxin, cocaine, sepsis and shock states are risk factors.
- Venous thrombosis: Rare, usually seen in hyper coagulable states.
- Atrial fibrillation
- Previous arterial-occlusive event
- Age >60
- Coronary artery disease
- Valvular heart disease
- Hyper-coagulable state
- Renal Failure
- Shock states
- Vaso-pressors/Vaso-active medications
This case presents an unstable elderly patient with mesenteric ischemia. The candidate must recognize abdominal pain in an elderly patient as a high risk diagnosis. The candidate must recognize that the patient is unstable based on vital signs.
The candidate should identify multiple risk factors for mesenteric ischemia including; age, previous arterial occlusion (CVA), atrial fibrillation, and digoxin use. The history, physical, progression of disease and laboratory findings are all consistent with mesenteric ischemia. The candidate should recognize that an elderly patient with severe abdominal pain and unstable vital signs represents a surgical emergency, and should ask for consultation prior to definitive diagnostic testing.
In order to pass this station the candidate must recognize mesenteric ischemia as a diagnostic possibility, arrange surgical consultation and appropriate definitive diagnostic testing.
This case is of moderate difficulty, mainly because the presentation is purposefully vague.