Block 22 Explanations
1) A 68-year-old man is brought to the emergency department following a high-speed automobile accident. He is alert and complains of chest pain and mild back pain. His blood pressure is 80/60 mm Hg. Chest x-ray shows a widened mediastinum, tracheal deviation, bronchial displacement, and loss of the aortic knob. Which of the following is the most likely diagnosis?
A. Cardiac tamponade
B. Myocardial contusion
C. Pulmonary contusion
D. Tension pneumothorax
E. Traumatic aortic rupture
Explanation:
The correct answer is
E. This patient has a traumatic aortic rupture, which is the most common cause of immediate death following a motor vehicle accident. Deceleration causes twisting of the aorta and may lead to rupture. Up to 90% of the individuals die at the scene, however a high index of suspicion and early intervention may save the remaining few. The symptoms include chest pain, back pain, and hypotension. Angiography is the gold standard and immediate surgery is mandatory. X-ray findings include widening of the mediastinum, alteration of the aortic knob, pleural cap, tracheal deviation, bronchial displacement, and esophageal deviation. Cardiac tamponade (choice A) often results from penetrating trauma near the heart and is caused by a fluid collection within the pericardium. The clinical features include hypotension, distended neck veins, pulsus paradoxus, and distant heart sounds. Pericardiocentesis is the treatment. Myocardial contusion (choice B) is most commonly seen when there is a direct blow to the chest wall. Findings include right ventricular dysfunction, arrhythmias, and an elevation of creatine kinase. An echocardiogram may document ventricular wall motion abnormalities. Pulmonary contusion (choice C) is a hemorrhage into the pulmonary parenchyma. It is characterized by dyspnea and hypoxia. Tension pneumothorax (choice D) occurs when air is trapped within the pleural space and leads to an increase in the intrathoracic pressure. Findings include jugular venous distention, hypotension, tracheal deviation, and a mediastinal shift. Tension pneumothorax often occurs following blunt trauma. Treatment is with needle thoracocentesis.
2) A football player is tackled, and he develops severe knee swelling and pain. On physical examination with the knee flexed at 90 degrees, the leg can be pulled anteriorly, like a drawer being opened. A similar finding can be elicited with the knee flexed at 20 degrees by grasping the thigh with one hand, and pulling the leg with the other. Which of the following is the most likely injured structure?
A. Anterior cruciate ligament
B. Lateral collateral ligament
C. Medial collateral ligament
D. Medial meniscus
E. Posterior cruciate ligament
Explanation:
The correct answer is
A. Swelling of the knee after trauma usually denotes the presence of a significant injury. The tests described (anterior drawer and Lachman test) are classic for an injury to the anterior cruciate ligament. The lateral collateral ligament (choice B), if disrupted, would allow the leg to be bent inward to a greater extent than normally possible (varus test). The medial collateral ligament (choice C), when injured, would produce the opposite findings: the leg could be bent outward more than the normal leg (valgus test). The medial meniscus (choice D), when injured, produces loose intraarticular bodies and locking of the knee. The posterior cruciate ligament (choice E) is much less commonly injured than the anterior cruciate. When it is injured, it produces the very opposite findings to those described in the vignette: the leg could be pushed backward, as if a drawer was being closed rather than opened.
3) A 33-year-old woman is undergoing a diagnostic work-up because she appears to have Cushing syndrome. She has elevated levels of cortisol, which are not suppressed when she is given high-dose dexamethasone. ACTH levels are greater than 200 pg/ mL. A chest x-ray film shows a central, 3-cm round mass on the hilum of the right lung. Bronchoscopy and biopsies confirm a diagnosis of small cell carcinoma of the lung. Which of the following is the preferred treatment for this woman?
A. Bilateral adrenalectomy
B. General support only
C. Pneumonectomy
D. Radiation and chemotherapy directed at the lung cancer
E. Trans-sphenoidal hypophysectomy and pulmonary lobectomy
Explanation:
The correct answer is
D. The endocrine workup is indicative of ectopic ACTH production, and the obvious site is small cell carcinoma of the lung. The lung cancer is what is going to kill this woman, not the endocrine manifestations of the tumor. Although small cell carcinoma of the lung is rarely cured, longer survival can be obtained with radiation and chemotherapy. Adrenalectomy (choice A) would address the endocrine problem by depriving the ectopic ACTH of its target gland. But, as pointed out above, the lethal disease here is the lung cancer. General support only (choice B) would lead to death in about 2 months. Radiation and chemotherapy can prolong survival by approximately 2 years. Pneumonectomy (choice C) is not the treatment for small cell carcinoma of the lung. It is the appropriate treatment for resectable and potentially curable non?small cell cancers of the lung. The combination of hypophysectomy and lobectomy (choice E) is wrong for several reasons. Pituitary microadenomas suppress with high-dose dexamethasone, and their production of ACTH is typically much lower than that seen in ectopic disease (i.e., <200 pg/mL). Thus, this woman does not need pituitary surgery. As far as the lung is concerned, surgery is not the treatment for small cell carcinoma, and lobectomy would not be applicable for a central, hilar tumor.
4) A 53-year-old woman comes to the physician because of a “lump” in her neck. She says that her masseuse noticed it 1 month ago. There is no associated pain, pressure, or hoarseness. She feels fine and has no other complaints. She has no history of radiation exposure. Examination reveals a palpable thyroid nodule that is approximately 3 cm. Which of the following is the most appropriate next step in diagnosis?
A. Cutting needle biopsy
B. Fine needle aspiration (FNA)
C. Neck ultrasound
D. Surgical resection
E. Thyroid hormone replacement
Explanation:
The correct answer is
C. An ultrasound is the first step in the evaluation of a palpable thyroid nodule. An ultrasound is a noninvasive technique that can determine if the nodule is cystic or solid, the exact size of the lesion, and whether there are any additional masses. If the nodule is cystic, a fine needle aspiration (FNA; choice B) is performed. If the cyst disappears and the cytology is benign, no additional treatment is necessary. If the cyst remains, further evaluation is necessary. If the nodule is solid and < 3 cm, an FNA is performed. If the cytology is benign, thyroid hormone replacement (choice E) is given to suppress growth. If the nodule is solid and > 3 cm., a needle biopsy (choice A) is performed. If the pathology is indeterminate or malignant, surgical resection (choice D) is the treatment. If the nodule is benign, thyroid hormone is given.
5) A 56-year-old man has been having bloody bowel movements on and off for the past several weeks. He reports that the blood is bright red, it coats the outside of the stools, and he can see it in the toilet bowl even before he wipes himself. When he does so, there is also blood on the toilet paper. After further questioning, it is ascertained that he has been constipated for the past 2 months and that the caliber of the stools has changed. They are now pencil thin, rather the usual diameter of an inch or so that was customary for him. He has no pain. Which of the following is the most likely diagnosis?
A. Anal fissure
B. Cancer of the cecum
C. Cancer of the rectum
D. External hemorrhoids
E. Internal hemorrhoids
Explanation:
The correct answer is
C. The combination of red blood coating the stools and a change in bowel habit and stool caliber spells out cancer of the rectum in someone in this age group. Anal fissure (choice A) is typically seen in young women who have very painful bowel movements with streaks of blood. Pain is the dominant symptom in this condition. Cancer of the cecum (choice B) leads to anemia and occult blood in the stools, but the blood is rarely seen. If it is, the entire stool is bloody. Furthermore, there is no change in bowel habit or stool caliber when the tumor is so proximal in the colon. External hemorrhoids (choice D) hurt and itch, but they rarely bleed. Internal hemorrhoids (choice E) do indeed bleed, but they do so without changing the pattern of bowel movements or the caliber of the stools.
6) A young man is shot with a .45 caliber revolver, point blank in the lower abdomen, just above the pubis. The entrance wound is at the midline, and there is no exit wound. X-ray films show the bullet embedded in the sacral promontory, to the right of the midline. Digital rectal examination and proctoscopic examination are negative, but he has gross hematuria. He is hemodynamically stable. Which of the following is the most appropriate next step in management?
A. CT scan of the abdomen
B. Intravenous pyelogram
C. Retrograde cystogram
D. Diagnostic peritoneal lavage
E. Exploratory laparotomy
Explanation:
The correct answer is
E. He has an obvious indication for exploratory laparotomy: a gunshot wound to the abdomen. He also has evidence of injury to the urinary bladder, but that will be dealt with at the same time that other intraabdominal injuries are found and repaired. CT scan (choice A) would not change the surgical approach and the surgical indication. CT scan is called for in cases of blunt trauma to diagnose intraabdominal bleeding and to identify intraabdominal injuries. Intravenous pyelogram (choice B) would indeed show the bladder injury, as would a retrograde cystogram (choice C). However, we already know clinically that there is a bladder injury: we know the trajectory of the bullet and we have blood in the urine. Diagnostic peritoneal lavage (choice D) is used to diagnose intraabdominal bleeding in blunt trauma, when the patient is not stable enough to be taken to the CT scanner. In many centers the diagnostic peritoneal lavage has been replaced by sonogram done in the emergency department by the trauma team.
7) A front-seat passenger in a car involved in a head-on collision relates that he hit the dashboard with his knees, however, he is specifically complaining of severe pain in his right hip, rather than knee pain. He lies in the stretcher in the emergency department with the right lower extremity shortened, adducted, and internally rotated. Which of the following is the most likely injury?
A. Femoral neck fracture
B. Fracture of the shaft of the femur
C. Intertrochanteric fracture
D. Posterior dislocation of the hip
E. Posterior dislocation of the knee
Explanation:
The correct answer is
D. The mechanism of injury is classic. As the knee hits the dashboard in the sitting position, the femoral head is driven backward and out of the socket. The position of the injured extremity is also typical, with the internal rotation produced by the posteriorly dislocated femoral head. This injury is an orthopedic emergency because of the tenuous blood supply of the femoral head. Femoral neck (choice A) and intertrochanteric (choice C) fractures are seen in elderly patients who fall and “hurt their hip.” They present with a shortened extremity that is externally rotated. A fractured shaft of the femur (choice B) would produce pain right there (not in the hip) and would have an obvious deformity where the thigh has an angulation that is clearly abnormal. Posterior dislocation of the knee (choice E) is also an orthopedic emergency because of the potential disruption of the popliteal artery, but the pain and the deformity would be at the knee.
A 71-year-old woman is brought to the physician by her distressed daughter. The daughter relates that, 3 days ago, her mother began to complain of right upper quadrant abdominal pain. She did not want to eat and “took to her bed sick.” The daughter recalls that she complained of chills, nausea, and some vomiting. Physical examination reveals an obtunded, hypotensive, and obviously very sick elderly woman. She has impressive pain to deep palpation in the right upper quadrant, along with muscle guarding and rebound. Her temperature is 40 C (104 F), and laboratory analysis shows a white cell count of 22,000/mm3 with multiple immature forms, a bilirubin of 5 mg/dL and alkaline phosphatase of 840 U/L. The serum amylase is normal. An emergency sonogram shows multiple stones in the gallbladder, normal thickness of the gallbladder wall without pericholecystic fluid, dilated intrahepatic ducts, and common duct with a diameter of 2.1 cm. The sonographer cannot identify stones in the common duct. In addition to IV fluids and antibiotics, which of the following is the most appropriate next step in management?A. Elective cholecystectomy
B. Emergency decompression of the common duct
C. Emergency cholecystectomy
D. Emergency surgical exploration of the common duct
E. Emergency transhepatic cholecystostomy
Explanation:
The correct answer is
B. The diagnosis is acute ascending cholangitis. This deadly disease is seen in patients with long-standing gallstones who get one or more stones in the common duct, where they produce partial obstruction that allows ascending infection. The fact that the sonographer cannot see the offending stones is irrelevant, as stones in the common duct are often not seen in sonograms. The study shows the indirect evidence of obstruction: dilated ducts. The chills, very high fever, and extremely elevated alkaline phosphatase are diagnostic. An advanced clinical form is present here, with obtundation, right upper quadrant tenderness, and hypotension. The key component of therapy is immediate decompression of the common duct, which is full of pus. How it is achieved is less important. Emergency endoscopic retrograde cholangiopancreatography (ERCP) is usually the first choice, but it can be done by percutaneous transhepatic cholangiography (PTC) or by open surgery. Elective cholecystectomy (choice A) will indeed be needed once the acute problem is resolved. But, if our planning included only such elective surgery, the patient would never get it: she would be dead. Emergency cholecystectomy (choice C) would not address the issue of pus in the common duct. She does not have acute cholecystitis, as evidenced by the normal thickness of the gallbladder wall and the absence of pericholecystic fluid. Furthermore, acute cholecystitis would not have produced the impressive levels of alkaline phosphatase. Surgical exploration of the common duct (choice D) is more than she can tolerate at this time. She does not need all the stones removed with a long operative procedure. She needs the pus out. The rest will come later. Cholecystostomy (choice E) is another choice for very sick people with acute cholecystitis, which is not the diagnosis.
9) A 25-year-old man is shot with a .22 caliber revolver. The entrance wound is in the anteromedial aspect of his upper thigh, and the exit wound is about 3 inches lower, in the posterolateral aspect of the thigh. He has a large, expanding hematoma in the upper inner thigh. There are no palpable pulses in the foot. The bone is intact by physical examination and x-ray films. Which of the following is the most appropriate next step in management?
A. Doppler studies
B. Venogram
C. Arteriogram
D. Embolectomy
E. Surgical exploration
Explanation:
The correct answer is
E. This one should be obvious. There is no question that the femoral vessels are injured, and the expanding hematoma plus absent pulses indicate that the femoral artery is involved (the vein may or may not be injured). Surgical exploration starts with proximal and distal control. Once the hematoma is safely entered, the extent of the injuries can be ascertained and the proper repair done. Doppler studies (choice A) are wonderful when we are trying to ascertain whether blood is flowing through a vessel. The clinical findings here are obvious. No fancy technology is needed. Venograms (choice B) are not needed prior to surgery. We can look at the vein during the operation. Arteriograms (choice C) are very often used in vascular trauma, but are not needed here. We would use an arteriogram if the anatomic location of the injury suggested vascular involvement, but the clinical signs did not confirm such suspicion. Arteriograms are also used when the specific surgical approach is dictated by precise knowledge of the site of extravasation, a situation that does not apply here. An embolectomy (choice D) will probably be done at the end of the surgical procedure, as a routine part of removing debris from the lumen of a vessel that has been repaired or re-anastomosed. However, embolectomy alone is the wrong answer for this vignette. The absent pulses are due to disruption of the artery, not to embolization from a distant source.
10) A 7-year-old boy passes a large, bloody bowel movement. He is hemodynamically stable, and he has a hemoglobin of 14 g/dL. Nasogastric aspiration yields clear, greenish fluid. Physical examination, including anoscopy, is unremarkable. Which of the following is the most appropriate next diagnostic test?
A. Celiac arteriogram
B. Colonoscopy
C. Radioactively labeled technetium scan
D. Radioactively tagged red cell study
E. Upper gastrointestinal endoscopy
Explanation:
The correct answer is
C. In this age group, with no obvious anal pathology and negative gastric aspirate, the leading cause of gastrointestinal bleeding is Meckel’s diverticulum. The specific source is ulceration of the normal ileal mucosa by acid produced by gastric mucosa in the diverticulum. The technetium scan identifies that ectopic gastric mucosa. Arteriogram (choice A) as a diagnostic step is a very invasive study that is appropriate only for very large hemorrhage (>2 mL/min) with clear gastric aspirate. An arteriogram may also be indicated for therapy (embolization) in severe gastrointestinal bleeding. Colonoscopy (choice B) would not identify the Meckel’s diverticulum. Colonoscopy is often needed in the older patient with lower gastrointestinal bleeding, in whom the source of the hemorrhage is likely to be polyps, cancer, diverticula, or angiodysplasia. A tagged red cell study (choice D) is often used as a prelude to an arteriogram in patients with substantial lower gastrointestinal bleeding. Upper gastrointestinal endoscopy (choice E) would have been appropriate if the gastric aspirate had produced blood.
11) An 81-year-old man with Alzheimer disease who lives in a nursing home undergoes surgery for a fractured femoral neck. On the 5th postoperative day, it is noted that his abdomen is grossly distended and tense, but not tender. He has occasional bowel sounds. The rectal vault is empty on digital examination, and there is no evidence of occult blood. X-ray films show a few distended loops of small bowel and a very distended colon. The cecum measures 9 cm in diameter, and the gas pattern of distention extends throughout the entire large bowel, including the sigmoid and rectum. No stool is seen in the films. Other than the abdominal distention, and the ravages of his mental disease, he does not appear to be ill. Vital signs are normal for his age. Which of the following is the most likely diagnosis?
A. Fecal impaction
B. Mechanical intestinal obstruction
C. Ogilvie syndrome
D. Paralytic ileus
E. Volvulus of the sigmoid colon
Explanation:
The correct answer is
C. Ogilvie syndrome is a type of colonic dysfunction often seen in elderly patients who are not too active to begin with and are then further immobilized by extra-abdominal surgery. Colonoscopy rules out obstructing cancer (always a consideration in this age group) and allows the gas to be sucked out as the instrument advances. A long tube is then left in place. Fecal impaction (choice A) is always a good thing to look for in old immobilized people with abdominal distention. However, the rectal vault would have been full of feces, and the x-ray films might have shown the fecal column extending up into the sigmoid and descending colon. Neither mechanical intestinal obstruction (choice B) nor paralytic ileus (choice D) would develop from hip surgery. When these complications occur after abdominal surgery, they affect primarily the small bowel, not the colon. Volvulus of the sigmoid (choice E) is another good thought in the distended old patient, but the radiologic picture would have been different, with a huge distended sigmoid way up into the right upper quadrant and tapering toward the left lower quadrant with the classic image of a “parrot’s beak.”
12) A 46-year-old woman was applying her make-up while also drinking her morning cup of coffee. She noticed in the mirror that a round, 2-cm mass would move up and down in the lower part of her neck whenever she swallowed. Her physician confirms that she has a single, firm, thyroid nodule in the right lobe. There are no other abnormalities in the history or physical examination. Her pulse is 82/min and regular. Thyroid stimulating hormone (TSH) is within normal limits. Which of the following is the most appropriate next step in management?
A. Clinical observation, repeating the TSH at least once a year
B. Determination of T3 and T4 levels
C. Radionuclide thyroid scan
D. Fine needle aspiration (FNA) cytology of the mass
E. Right thyroid lobectomy
Explanation:
The correct answer is
D. Most thyroid nodules are benign, and surgery must be reserved for selected candidates with the highest likelihood of malignancy. Fine needle aspiration (FNA) is the best way to make the selection. If read by an experienced pathologist as negative for cancer, patients can be safely followed. If read as either indeterminate or positive for cancer, surgery would be required. Choosing surgical candidates this way, cancer is found at surgery in 20% to 40% of patients operated, a vast improvement over earlier selection methods, where the yield was around 10% to 15%. Clinical observation alone (choice A) would not be appropriate. Thyroid cancers grow slowly, but they still need to be diagnosed and treated. Incidentally, they typically do not affect thyroid function, so that following the TSH would not alert you to the presence of malignancy. Thyroid nodules can be benign but hyperfunctioning (toxic adenoma), and therefore thyroid function must be determined. But, that has already been done here with the normal TSH. Further pursuit of T3 and T4 (choice B) is unnecessary in someone with no clinical evidence of hyperfunction (normal pulse). Thyroid scan (choice C) would have been the answer 10 or 20 years ago, before FNA displaced it as the best way to select surgical candidates. In the old days, a cold nodule raised suspicions of malignancy but gave low yields at surgery. Without a diagnosis of cancer, or an indeterminate FNA, one cannot justify the extremely aggressive approach of surgery as the next step in management. Thus, choice E is clearly wrong.
13) A 44-year-old woman is recovering from a mild episode of acute ascending cholangitis secondary to choledocholithiasis. When seen initially, she had a spiking fever, leukocytosis, and a very high alkaline phosphatase; however, all these findings subsided rapidly after she was placed on IV antibiotics. A sonogram of the right upper quadrant on the day of admission showed the presence of gallstones in the gallbladder, but the diameter of the biliary ducts was normal. It was assumed that she had passed a common duct stone, and plans to do an endoscopic retrograde cholangiopancreatogram (ERCP) were canceled. While awaiting elective cholecystectomy, she again developed a fever and leukocytosis, and her liver function tests showed minimal elevation of her bilirubin (to 2.5 mg/dL) and alkaline phosphatase (to 115 U/L). A repeat sonogram shows no changes in her biliary ducts, but now there is a 6-cm abscess in the right lobe of the liver. Which of the following is the most appropriate treatment for this new development?
A. Metronidazole
B. Long-term IV antibiotics
C. ERCP and biliary drainage
D. Percutaneous drainage of the liver abscess
E. Open surgical resection of the right lobe of the liver
Explanation:
The correct answer is
D. Liver abscess complicating biliary tract disease is described as “pyogenic” abscess (to contrast it with amebic abscess), and it requires drainage like any abscess anywhere else in the body. The percutaneous route is favored. Metronidazole (choice A) is the therapy of choice for amebic abscesses of the liver, and that condition represents the only exception to the rule that all abscesses have to be drained. However, this is not an amebic abscess. Amebic abscesses are seen in men (4 to 1 ratio compared with women) who come from Mexico, where the disease is very common. Long-term antibiotics (choice B) will not reach and sterilize an abscess. Abscesses have to be drained. Endoscopic retrograde cholangiopancreatogram (ERCP) (choice C) is often urgently needed to treat acute ascending cholangitis, but it will not do anything for a liver abscess. Resection (choice E) is not needed for a liver abscess. Drainage is enough.
14) A 55-year-old, HIV-positive man has a fungating mass growing out of the anus. He can feel it when he wipes himself after having a bowel movement, but it is not painful. For the past 6 months, he has noticed blood on the toilet paper, and from time to time there has also been blood coating the outside of the stools. He has lost weight, and he looks emaciated and ill. On physical examination, the mass is easily visible. It measures 3.5 cm in diameter, is fixed to surrounding tissues, and appears to grow out of the anal canal. He also has rock-hard, enlarged lymph nodes on both groins, some of them as large as 2 cm in diameter. Which of the following is the most likely diagnosis?
A. Adenocarcinoma of the rectum
B. Condyloma acuminata of the anus
C. External hemorrhoids
D. Rectal prolapse
E. Squamous cell carcinoma of the anus
Explanation:
The correct answer is
E. The entire description is classic for anal cancer, but the clincher is the presence of metastasis in the inguinal nodes. Adenocarcinoma of the rectum (choice A) could look like this if it arose very low in the rectum, but it would not metastasize to inguinal nodes. Condyloma acuminata (choice B) could give fungating masses, but it would not lead to cachexia and would not produce the rock-hard inguinal nodes. Viral infections may precede the development of this kind of tumor (and could coexist with it), but it would be wrong to assume that all the patient has is the benign viral process. External hemorrhoids (choice C) are not fungating masses, they do not bleed, and they do not lead to inguinal adenopathy or cachexia. Rectal prolapse (choice D) would produce a protruding mass with concentric mucosal folds, would come in and out with straining, and would be a nuisance–but it would not produce adenopathy and cachexia.
15) A 79-year-old man with atrial fibrillation develops an acute abdomen. When seen 2 days after the onset of the abdominal pain, he has a silent abdomen, with diffuse tenderness and mild rebound. There is a trace of blood on the rectal examination. He also has acidosis and looks quite sick. X-ray films show distended small bowel and distended right colon, up to the middle of the transverse colon. Which of the following is the most likely diagnosis?
A. Acute pancreatitis
B. Mesenteric ischemia
C. Midgut volvulus
D. Perforated viscus
E. Primary peritonitis
Explanation:
The correct answer is
B. The setting of an old patient with atrial fibrillation (or a recent myocardial infarction) who develops an acute abdomen, strongly suggests embolus to the mesenteric vessels. The combination of abdominal pain and a trace of blood in the lumen is also typical, as is the x-ray film outlining the territory supplied by the superior mesenteric. He probably has a dead bowel by now, as evidenced by his acidosis and severe illness. Any one of the other options could exist, but none are the most likely. Acute pancreatitis (choice A) would be expected in an alcoholic or a patient with biliary tract disease. There would have been no blood in the lumen. Midgut volvulus (choice C) would be far more likely to happen to an infant with malrotation. A perforated viscus (choice D) is indeed possible, but the x-ray films would have shown free air rather than distended bowel. Primary peritonitis (choice E) would have been a consideration in a patient with preexisting ascites.
16) A 42-year-old, right-handed man has had a history of progressive speech difficulties and right hemiparesis for 5 months. He has had progressively severe headaches for the past 2 months, which are worse in the mornings. At the time of admission, he is confused and vomiting, and has blurred vision, papilledema, and diplopia. Shortly thereafter, his blood pressure increases to 190/110 mm Hg, and he develops bradycardia. Which of the following is most likely the significance of the hypertension and the bradycardia?
A. The brain tumor has produced tentorial herniation
B. The brain tumor is pressing on the hypothalamus
C. The chronic subdural hematoma has ruptured
D. The genesis of his symptoms is aortic dissection
E. There is a near-terminal increase in intracranial pressure
Explanation:
The correct answer is
E. The clinical picture is that of a brain tumor with increased intracranial pressure. However, the development of hypertension and bradycardia (Cushing’s reflex) signifies that the brain has run out of compensatory mechanisms to minimize the intracranial pressure elevation generated by increased intracranial volume. When that point is reached, brain perfusion suffers and death is imminent. Choices A and B correctly identify the disease as a brain tumor, but assign an incorrect meaning to the hemodynamic changes. Tentorial herniation would lead to respiratory arrest. Pressure on the hypothalamus is not the reason for the Cushing’s reflex. Choice C makes a wrong diagnosis. Chronic subdural hematomas are seen in very old or alcoholic patients, where they press on the cortex-but do not “rupture” and create a sudden catastrophe in that fashion. Aortic dissection (choice D) happens to hypertensive patients, but what they get is chest and back pain, not a long-standing neurologic picture as depicted here.
17) After a grand mal seizure, a 32-year-old epileptic woman notices pain in her right shoulder, and she cannot move it. She goes to a minor emergency clinic, where she has a limited physical examination and anteroposterior (AP) x-ray films of her shoulder. The films are read as negative, and she is diagnosed as having a sprain and given pain medication. The next day, she still has the same pain and is unable to move her arm. She comes to the emergency department holding her arm close to her body, with her hand resting on her anterior chest wall. Which of the following is the most likely diagnosis?
A. Acromioclavicular separation
B. Anterior dislocation of the shoulder
C. Articular cartilage crushing
D. Posterior dislocation of the shoulder
E. Torn teres major and minor muscles
Explanation:
The correct answer is
D. The mechanism of injury (massive contraction of all muscles in the area) and the missed diagnosis on a single view AP x-ray film are classic for posterior dislocation of the shoulder. Axillary view x-ray films are needed to make the diagnosis. Acromioclavicular separation (choice A) would have been obvious on physical examination and on the x-ray film taken Anterior dislocation (choice B) is far more common than posterior dislocation. However, it happens with regular trauma, has a very typical posture where the arm is held close to the body but the forearm and hand are rotated out as if ready to shake hands, and is easily seen on x-ray films. Crushing of the articular cartilage (choice C) and tearing of shoulder girdle muscles (choice E) are not common injuries following seizures.
18) A 69-year-old man who smokes and drinks and has rotten teeth, has a hard, fixed, 4-cm mass in his left neck. The mass is just medial to and in front of the sternomastoid muscle, at the level of the upper notch of the thyroid cartilage. It has been there for at least 6 months, and it is growing. Which of the following is the most appropriate next step in diagnosis?
A. Radionuclide scan of the thyroid gland
B. Sputum cytology and CT scan of the lungs
C. Panendoscopy (triple endoscopy) and mucosal biopsies
D. Open incisional biopsy of the mass
E. Open excisional biopsy of the mass
Explanation:
The correct answer is
C. In this setting (old man who smokes and drinks and has rotten teeth), the clinical diagnosis is metastatic squamous cell carcinoma to a cervical lymph node, from a primary (or multiple primaries) somewhere in the mucosa of the aerodigestive tract. Endoscopy and biopsies should establish the diagnosis. Thyroid cancer could indeed metastasize to neck nodes, sometimes before the primary tumor is palpable. In this particular setting, however, a radionuclide scan (choice A) would be a very distant second choice. Sputum cytology and CT scan of the lungs (choice B) is another tempting thought for a smoker. But, when lung cancer metastasizes to the cervical nodes, it affects the supraclavicular nodes, not the nodes higher up in the neck. Open biopsy of the neck mass is an absolute no-no, whether it is excisional (choice E) or incisional (choice D). Doing so will in fact confirm the diagnosis, but at the cost of contaminating the tissues and interfering with the placement of incisions for the definitive surgery. Furthermore, the location of the primary (or primaries) would not be established.
19) On the 5th postoperative day, it is noticed that large amounts of clear, pink, salmon-colored fluid are soaking the wound dressings of a patient who had a negative exploratory laparotomy for a stab wound of the abdomen. The laparotomy was done through a midline supraumbilical and infraumbilical incision. When seen by the surgical staff, the patient is lying in bed in the supine position, with the dressings removed. In the dim light of his hospital room, the incision appears intact and not particularly red or inflamed, but there are indeed traces of the clear pink fluid on his skin. He has no specific complaints. He is still NPO and on IV fluids, but has already been passing gas per rectum, and plans had been made to feed him today. The abdomen is not distended, and he has normal bowel sounds. He is afebrile. Which of the following is the most appropriate next step in management?
A. Culture the pink fluid and start empiric antibiotic therapy
B. Gently probe the wound at several points until pus is found and drained
C. Help the patient out of bed and have him walk to the examining room for proper inspection of the wound
D. Stop plans for oral feedings and start total parenteral nutrition
E. Tape the wound securely, bind the abdomen, and avoid events that would suddenly increase his intra-abdominal pressure
Explanation:
The correct answer is
E. The situation described is that of a wound dehiscence that has not yet progressed to a wound evisceration. The former can be dealt with at leisure, if the latter is avoided. He will eventually require re-closure, but it can be done whenever it is most convenient. Cultures and antibiotics (choice A) assume the pink fluid to be a sign of infection. It is not. It is normal peritoneal fluid (with a trace of blood still in it from the recent surgery) that is seeping out through the unhealed wound. Probing (choice B) will not produce pus, but it might hasten the dreaded evisceration. He is afebrile, and the wound is not red. Clear pink salmon-colored fluid means dehiscence, not infection. Getting the patient out of bed (choice C) is the last thing you want to do. If this advice were followed, the person helping the patient would soon be looking at a handful of small bowel as it comes rushing out of the belly. The fluid described is not bowel contents; this is not a fistula. There is no need to go to parenteral nutrition (choice D).
20) A 2-year-old child has been shot in the arm in a drive-by shooting. His brachial artery was partially transected, and there was copious bleeding. The EMTs control the site of bleeding by local pressure, and the child is no longer losing blood; however, he is hypotensive and tachycardic. IV fluid resuscitation is urgently needed, but several attempts at starting peripheral IV lines have been unsuccessful. Which of the following would be the best alternative route in this situation?
A. Central line via subclavian puncture
B. Hypodermoclysis
C. Intraosseous cannulation in the proximal tibia
D. Percutaneous femoral vein cannulation
E. Saphenous vein cut-down
Explanation:
The correct answer is
C. In very small children, the preferred alternate route, if peripheral veins cannot be cannulated, is the placement of a trocar in the bone marrow of a long bone. The upper tibia is usually chosen. Subclavian puncture (choice A) was at one time routinely used in the resuscitation of patients in shock, but it is now recognized that it is invasive and has many possible complications. Furthermore, frequently in the trauma setting, the head and neck and upper thorax are not accessible, as many other life-saving and diagnostic examinations are being done. The extremities, on the other hand, are free to be used. The subcutaneous tissue (choice B) cannot take fluid fast enough to meet the needs here, The femoral vein by percutaneous puncture (choice D) or a saphenous vein cut-down (choice E) are the preferred alternate routes in an adult when peripheral veins cannot be rapidly cannulated.
21) A 24-year-old woman sustains multiple injuries in a car accident, including a pelvic fracture. She is hemodynamically stable. Initial assessment shows no vaginal or rectal injuries; however, when a Foley catheter is inserted, bloody urine is recovered. Which of the following would be the best way to evaluate her urologic injury?
A. Sonogram of the bladder
B. Intravenous pyelogram
C. Cystoscopy
D. Retrograde cystogram including post-void films
E. Retrograde cystogram including views of the ureters
Explanation:
The correct answer is
D. Bloody urine plus pelvic fracture equals bladder injury in either gender, or bladder or urethral injury in the male. In this case, with the very short and well-protected female urethra not being suspected, only the bladder is the obvious candidate. Injecting dye and taking x-ray films will show the extravasation, but it is important to include post-void films because extravasation at the bladder neck can be obscured by the dye that is filling the bladder. Sonogram (choice A) is a good, noninvasive way to look at things, but here we can get far better detail with a study (the retrograde cystogram) that is not particularly invasive. Intravenous pyelogram (choice B) would show dye extravasation, but with far less detail than that provided by direct injection. Cystoscopy (choice C) would be invasive and not easy to do. When a cystoscopy is done, fluid is injected into the bladder to expand it and see the walls. In this case, the injected fluid would go out into the peritoneal cavity or the preperitoneal space. Looking at the ureters (choice E) is not necessary when bladder injury is suspected. The ureters are rarely injured in blunt trauma.
22) A 62-year-old woman has a 4-cm, hard mass under the nipple and areola of her rather small left breast. The mass occupies most of the breast, but the breast is freely movable from the chest wall. There is no dimpling or ulceration of the skin over the mass, and careful palpation of the axilla is completely negative. A core biopsy of the breast mass has established a diagnosis of infiltrating ductal carcinoma, and the mammogram showed no other lesions in that breast or the other one. A chest x-ray film and liver function tests are normal. She has no symptoms suggestive of brain or bone metastasis. Which of the following should be offered to this woman
A. Lumpectomy only
B. Lumpectomy with axillary sampling and post-op radiation
C. Total mastectomy only
D. Modified radical mastectomy (including axillary sampling)
E. Radical mastectomy (including complete axillary dissection)
Explanation:
The correct answer is
D. The mass is too large, in a breast that is too small, to allow an adequate lumpectomy. Local control of the tumor requires mastectomy. However, mastectomy alone is not sufficient. We need to know what is happening in the axilla to make a decision regarding postoperative systemic therapy. The physical examination was negative, but the reliability of that finding is not much better than flipping a coin. Lumpectomy alone (choice A) cannot be done here, and it would not be the appropriate management even if the cancer had been smaller. Lumpectomy, axillary sampling, and post-op radiation (choice B) would have been the correct answer for a smaller tumor in a larger breast. Total mastectomy alone (choice C) would have been a wise palliative choice if she had had evidence of distant metastasis. She does not. We have to go for cure. We need the standard potentially curative operation: modified radical mastectomy, which includes axillary sampling. Radical mastectomy (choice E) is no longer used for the treatment of breast cancer. It offers no survival advantage over the less mutilating modified radical.
23) A 54-year-old man, who 5 years ago underwent a laparotomy for a gunshot wound to the abdomen, is admitted to the hospital because of protracted vomiting and progressive abdominal distention. The symptoms began 5 days earlier, and since then he has not had a bowel movement or passed any gas. At the time of hospitalization, he has hyperactive bowel sounds and some abdominal discomfort, but does not have an acute abdomen. His abdominal x-ray films show dilated loops of small bowel, multiple air-fluid levels, and no free air under the diaphragms. He is placed on nasogastric suction and IV fluids. After 6 hours, he develops fever, leukocytosis, abdominal tenderness, and rebound tenderness, and his abdomen is silent. Which of the following is the most appropriate next step in management?
A. Add antibiotics
B. Barium tag and serial abdominal x-ray films
C. CT scan of the abdomen
D. Upper gastrointestinal endoscopy and introduction of a long intestinal tube
E. Emergency exploratory laparotomy
Explanation:
The correct answer is
E. He came in with mechanical intestinal obstruction due to adhesions, and has now developed signs of bowel strangulation. If the strangulated loop is still viable, it has to be freed immediately. If it is necrotic, it has to be resected with equal urgency to prevent continued peritoneal soiling. Antibiotics (choice A) will not provide viability to a compromised loop of bowel, nor prevent peritonitis if the loop is dead. Barium tag (choice B) is what we do in the postoperative period after abdominal surgery when we cannot decide whether a sluggish bowel has paralytic ileus or early mechanical obstruction. This is not the situation here. CT scan (choice C) is our universal answer when we do not know what is happening inside the belly. Here we do. Had he shown up with obstruction, and no reasonable etiology for it (no prior surgery, no hernias), we might have done a CT. Endoscopy and a long tube (choice D) will not take care of dead or dying bowel.
24) While running to catch a bus, and old man twists his ankle and falls on his inverted foot. Anteroposterior (AP), lateral, and mortise x-ray films show displaced fractures of both malleoli. Which of the following would be the preferred form of treatment?
A. Closed reduction and casting
B. Skeletal traction
C. Open reduction and internal fixation
D. Replacement with a metal prosthesis
E. Fusion of the ankle joint
Explanation:
The correct answer is
C. Precise alignment of the displaced fragments is needed to ensure that the tight mortise of the ankle joint is restored. Closed reduction and casting (choice A) is unlikely to provide the necessary realignment. Skeletal traction (choice B), in general, is indicated only in areas of the body where strong muscle groups pull broken bones into unacceptable positions. Artificial joints are usually used for advanced articular disease. In the trauma setting, replacement with a prosthesis (choice D) is as a rule reserved for fractures where avascular necrosis is predictable. Fusion of a joint (choice E) is the ultimate step when everything else has failed. It would not be the first choice for a relatively common fracture.
25) A 19-year-old man sustains multiple injuries in a high-speed automobile collision. There is a pneumothorax on the left, for which he has a chest tube placed. Over the next several days, a large amount of air drains continuously through the tube (a large “air leak”), and daily chest x-rays show that his collapsed left lung is not expanding. The patient is not on a respirator. Which of the following is the most likely cause of these findings?
A. Air embolism
B. Injury to the lung parenchyma
C. Injury to a major bronchus
D. Insufficient suction being applied to the chest tube
E. Tension pneumothorax
Explanation:
The correct answer is
C. This patient most likely has an injury to a major bronchus. In addition to the wrenching effect of a sudden deceleration, these can happen when a major blow to the chest occurs at a time when the glottis is closed. If not recognized right away by the presence of subcutaneous emphysema, they become evident once the air leak persists and the lung does not re-expand. Air embolism (choice A) is manifested by sudden death shortly after a patient with unrecognized injuries to the tracheobronchial tree in proximity to major intrathoracic vessels is placed on a respirator. Injured lung parenchyma (choice B) can indeed leak air and produce a pneumothorax, but it typically heals rapidly. It is the delayed resolution of the pneumothorax that suggests that a major bronchus, rather than lung parenchyma, has been damaged. Suction applied to a chest tube (choice D) is used to accelerate the rate of resolution of a pneumothorax, but the large amount of air draining in this case indicates that the pleural space fills in as quickly as it is being drained out. No amount of suction can keep up with what literally is a situation in which the chest tube is sucking out the air in the room, by way of the bronchial tear. Tension pneumothorax (choice E) occurs when air cannot leave the pleural space and pressure builds up within. The manifestations are respiratory distress and extrinsic cardiogenic shock.
Tags: Surgery
