A 58 year old man complains of bleeding during defecation. When you try to examine his anus, it is so painful for him that you cannot proceed with the rectal examination.
What is the most likely cause?
Correct Answer C: An anal fissure is an acute longitudinal tear or a chronic ovoid ulcer in the squamous epithelium of the anal canal. It causes severe pain, sometimes with bleeding, particularly with defecation.
Anal fissures are believed to result from laceration by a hard or large stool, with secondary infection. Trauma (eg, anal intercourse) is a rare cause. Fissures cause severe pain and bleeding. The pain typically occurs with or shortly after defecation, lasts for several hours, and subsides until the next bowel movement. Examination must be very gentle but with adequate spreading of the buttocks to allow visualization.
Diagnosis is made by inspection. Treatment is with stool softeners, sitz baths and nitroglycerin ointments. When conservative measures fail, surgery (internal anal sphincterotomy or controlled anal dilation) is needed to interfere with the cycle of internal anal sphincter spasm. Piles (hemorrhoids) are painful but usually examination is possible. Constipation is unlikely to have this presentation.
A 38 year old male is admitted to the hospital after being found lying on the floor unconscious from a drug overdose. The next morning, he is alert and complains of constant pain in the anterior aspect of his left leg. On examination, you note pain with passive stretching, pain with palpation anteriorly, and a slightly decreased dorsalis pedis pulse on the left. There is no edema or erythema. Radiographs of the lower extremity are normal.
Which one of the following would you do now?
Correct Answer E: The patient has a history and symptoms very suggestive of a compartment syndrome of the anterior compartment of the left leg. A common cause of this serious problem is limb compression during prolonged recumbency related to drug or alcohol overdose. Early diagnosis and treatment are essential in order to avoid permanent, severe disability.
The five “P’s” of compartment syndrome are pain, pallor, paresthesias, pulselessness, and paralysis. If distal pulses are reduced, then muscle necrosis has occurred and immediate surgical consultation is necessary. Duplex Doppler ultrasonography and impedance plethysmography are used to evaluate for deep venous thrombosis. Given the decreased pulses, however, this diagnosis is much less likely and such testing may needlessly delay urgent surgical treatment. Intravenous antibiotics would be appropriate for cellulites. This diagnosis is unlikely in this scenario given the absence of fever, erythema, and edema, and the presence of a diminished pulse. Rest, ice, and elevation are inappropriate treatment modalities for compartment syndrome.
What is the most appropriate treatment of Clostridial gas gangrene?
Correct Answer B: Clostridial gas gangrene is a highly lethal necrotizing soft tissue infection of skeletal muscle caused by toxin- and gas producing Clostridium species. [Clostridium perfringens, is the most common cause of clostridial gas gangrene (80- 90% of cases). Other clostridia species responsible for the condition include Clostridium novyi (40%), Clostridium septicum (20%), Clostridium histolyticum (10%), Clostridium bifermentans (10%), and Clostridium fallax (5%)].
Clostridium infection of a wound is an emergency as it can lead to rapid onset of myonecrosis with muscle swelling, severe pain, gas production, and sepsis. Generally the treatment is a combination of antibiotics, surgery, and hyperbaric oxygen. Surgical treatment is with wide debridement of necrotic muscle.
Hyperbaric oxygen inhibits clostridial growth, exotoxin production, and exotoxin binding to host tissues. It should be used at the discretion of the treating physician but should never cause a delay in surgical debridement.
A 62-year-old male presents for surgical clearance prior to transurethral resection of the prostate. His past history is significant for a pulmonary embolus after a cholecystectomy 15 years ago. His examination is unremarkable except that he is 23 kg (50 lb) overweight.
The most appropriate recommendation to the urologist would be to:
Correct Answer C: A patient with history of postoperative venous thromboembolism is at risk for similar events with subsequent major operations. The most appropriate treatment of the choices listed would be subcutaneous enoxaparin.
→ Aspirin is ineffective for prophylaxis of venous thromboembolism.
→ Warfarin is effective at an INR of 2.0 - 3.0.
→ Full anti-coagulation with heparin is unnecessary for prophylaxis and can result in a higher rate of postoperative hemorrhage.
A 78-year-old man underwent a hip replacement 5 days ago for severe hip osteoarthritis. He suddenly became dyspneic and complained of sharp pleuritic chest pain. Vital signs show a BP of 110/60 mm Hg, pulse is 120/min; RR is 30/min and his temp is 37°C. Pulse Oximetry shows 80% saturation on 100% mask oxygen. Lung exam is within normal limits, chest x-ray is unremarkable and the EKG shows sinus tachycardia.
Which of the following would be the most appropriate next step of management?
Correct Answer E: In a patient who has had recent surgery and presents with shortness of breath and tachycardia, the diagnosis of pulmonary embolus (PE) must always be suspected. V/Q scan or CT angiogram of the chest are appropriate for diagnosis.
→ Alprazolam (choice A) would be appropriate for an acute panic attack NOT for a PE.
→ Contrast-enhanced (NOT without contrast) CT scanning (choice B) is increasingly used as the initial radiologic study in the diagnosis of pulmonary embolism, especially in patients with abnormal chest radiographs in whom scintigraphic results are more likely to be nondiagnostic.
→ Venogram of the lower limb (choice C) is invasive and has been replaced by duplex ultrasound when DVT is suspected.
→ D-dimer (choice D) is a sensitive but poorly specific diagnostic tool for patients with suspected PE. An elevated D-dimer alone is insufficient for the diagnosis of PE. D-dimer levels are most useful when used in conjunction with clinical suspicion to facilitate for the decision to proceed with further testing.
Note: If contrast-enhanced CT were among the answers, it would be the correct choice.
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