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Answers and Explanations

1. The answer is D (Chapter 7, V A 1 a). The triad of a cardiac arrhythmia, the sudden onset of severe abdominal pain, and gut emptying is a classic indicator of embolic mesenteric ischemia. This combination constitutes a surgical emergency, and the patient should be treated promptly with vigorous rehydration followed by arteriography to confirm the diagnosis. Rapid embolectomy of the superior mesenteric artery could save this patient, provided that no delay occurs in her definitive surgical treatment.

Cholecystitis usually presents with right upper quadrant pain and diverticulitis with left lower quadrant pain. A perforated ulcer will have associated diffuse abdominal tenderness but also wil have signs of peritoneal irritation (guarding and rebound). A small bowel obstruction usually presents with colic or intermittent pain.

2. The answer is B (Chapter 7, VIII E 2 a–e ). The symptomatic artery is usually repaired first because it carries the highest risk of stroke. Percutaneous transluminal angioplasty of the carotid artery is presently under investigation as an alternative to carotid endarterectomy, but it is not considered to be the standard of care at this point. Percutaneous transluminal angioplasty is sometimes used for smooth, regular lesions associated with fibromuscular dysplasia. The superficial temporal artery to middle cerebral artery bypass has not been shown to be effective for this patient's disease. Bilateral carotid endarterectomy is usually not performed because of the risk of recurrent laryngeal nerve trauma, which, if bilateral, could result in a tracheostomy.

3–4. The answers are 3-D (Chapter 7, VIII A ), 4-D (Chapter 7, VIII A 3). Colonoscopy is not indicated if the patient's stool is heme negative. Computed tomography (CT) can help to evaluate the proximal extent of the aneurysm. Pulmonary function tests can help to assess risk and to help plan perioperative care. An arteriogram acts as a road map, showing the renal arteries in relation to the aneurysm and the extent of occlusive disease in the iliac and femoral arteries. A Persantine thallium scan helps to define perioperative cardiac risk.

Elective repair of an abdominal aortic aneurysm (AAA) can be performed with a mortality rate lower than 5%. The leading cause of death in these patients with AAA is rupture. A 6-cm AAA has a 35% rupture rate, and surgery should be recommended unless the patient has a life expectancy of less than 1 year. Rate of enlargement is not a safe predictor of risk of rupture. Patients with symptomatic or rupturing AAA have a 75% mortality rate when operated on as an emergency. An aorto -bi -iliac graft is the appropriate procedure in this patient, rather than a tube graft, to repair the associated iliac aneurysm. With no iliac occlusive disease, an aortoiliac bypass avoids groin incisions.

5. The answer is D (Chapter 8, I B 3). A swollen leg following a period of immobilization is a typical history leading to a deep venous thrombosis (DVT). While lymphedema or other causes can also lead to leg swelling, a pelvic CT scan would not be the next step for this patient. Physical examination is reliable only 50% of the time for DVT, so an accurate diagnostic study such as a venous duplex ultrasound is needed before starting long-term anticoagulation. If no other reason for the swelling can be found, a pelvic CT scan may be reasonable. Leg elevation is helpful to reduce swelling, but compression stockings are not recommended in the acute phase for fear of dislodging the clot. Aspirin is of no proven benefit in treating DVT.

6–9. The answers are 6-A [Chapter 8, I B 3 c (1)–(4) ], 7-B [Chapter 8, I B 3 d (1)], 8-E [Chapter 8, I B 3 f (1)]. Physical examination is the least likely method to diagnose the cause of acute leg swelling. Currently, such a patient would undergo duplex ultrasonography or venography to confirm the presumed diagnosis of DVT. Impedance plethysmography can detect increased resistance to venous flow but does not identify the

cause. 125 I Fibrinogen scanning can identify ongoing thrombosis, but the scan takes 24 hours to complete and is therefore not useful in acute situations.

Intravenous heparin therapy is the most appropriate initial treatment. Subcutaneous unfractionated heparin

therapy in its current form is not acceptable treatment for DVT. Thrombolytic therapy would be contraindicated in a patient with a recent craniotomy because it would increase the risk of hemorrhage. P.175

Aspirin therapy has no role in the treatment of DVT. Warfarin can be used once the patient is discharged but not as the initial treatment. Transition from intravenous heparin to warfarin therapy should occur on the fourth or fifth day of heparin administration.

Support hose is the mainstay of treatment for patients with chronic postphlebitic syndrome. Thrombectomies have been unsuccessful, and the efficacy of venous bypass has yet to be established. There is interest in transplanting venous valves and segments of a vein to replace short-segment thromboses, but this area is still experimental. Prosthetic grafts have no role in venous reconstruction. Chronic diuretic therapy may be useful for short-term therapy but is certainly not optimal long-term management for this problem.

9. The answer is D (Chapter 8, I B 3 e). The risk of DVT can be reduced by simple measures such as leg elevation, early mobilization, support hose, and sequential compression devices. Unfractionated heparin administered subcutaneously either two or three times a day or low molecular weight heparin can both reduce the risk of DVT, but either should be started prior to surgical procedures.

Chapter 9

Common Life-threatening Disorders

Vincent T. Armenti

Bruce E. Jarrell

I Acute Abdomen

A Definition

Acute abdomen is the term used for an episode of severe abdominal pain with an acute onset (<8 hours) that lasts for several hours or longer and requires medical attention. Prompt diagnosis is important because an acute abdomen is caused by an intra -abdominal emergency in most patients.

B Symptoms

The history obtained from the patient should elicit both specific symptoms typical of a disease process and nonspecific symptoms.

Nonspecific symptoms should be elicited first.

Pain

Gradual periumbilical pain indicates visceral peritoneal irritation, such as appendicitis, diverticulitis, or other inflammatory conditions. The pain may become more specifically localized as the disease process progresses.

Severe, explosive pain indicates a process that immediately soils the parietal peritoneum, such as perforation of a hollow viscus. The pain may be either localized or generalized.

Progressive, severe pain suggests a worsening intra -abdominal condition, such as that which occurs with ischemic necrosis of the bowel or other organs.

Localized pain that recurs as a generalized pain suggests that the inflamed organ has been perforated. For example, acute appendicitis causes right lower quadrant pain, which then becomes generalized if perforation occurs.

Crampy pain indicates an obstruction in the gastrointestinal (GI) tract. This type of pain has a crescendo component, building up to intense pain, followed by a decrescendo component; the patient may then have an interval with no pain.

Distinguishing between crampy pain versus constant or other types of pain is very important because crampy pain is associated with bowel obstruction.

If crampy pain develops into constant severe pain, it suggests that the involved bowel segment is now ischemic or gangrenous.

Anorexia, nausea, and vomiting are common accompanying symptoms in acute inflammatory abdominal processes. Although they are reliably present when a problem is surgical, they also accompany nonsurgical diseases, in which case they often precede the pain (as in gastroenteritis).

Changes in bowel habits are so common that they are seldom helpful unless very specific changes occur. For example:

Bloody diarrhea suggests colitis, Salmonella infestation, or colonic ischemia.

Patients with intestinal obstruction usually pass no flatus or bowel movement by rectum for 1–2

days prior to seeking medical attention.

Symptoms of sepsis , such as chills and fever, may be nonspecific, although certain patterns are typical of certain diseases. For example:

The fever of uncomplicated appendicitis rarely exceeds 101 °F , whereas that of perforation often exceeds 101 °F .

Cholangitis with choledocholithiasis is often accompanied by a shaking chill.

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Specific symptoms should be elicited as clues to specific diseases.

Previous surgery. A history of previous surgery yields important information.

Adhesions may have formed within the peritoneal cavity, leading to intestinal obstruction.

If the surgery was for malignant disease, the malignancy may have recurred, causing pain, sepsis, intestinal obstruction, and other symptoms.

Previous removal of any organ (most likely the appendix, the gallbladder, or the uterus, ovaries, and fallopian tubes) eliminates that organ from consideration.

Previous surgery may point to a specific problem; e.g., suppurative cholangitis in a patient with previous choledocholithiasis and retained common duct stone.

Previous episodes of similar pain warrant questions about the subsequent disease course and the results of any diagnostic studies that were performed.

Characteristic maneuvers in certain diseases that provide temporary relief of pain must be sought.

A patient with acute peritonitis will lie very still; any movement results in excruciating pain.

A patient with a common duct stone or a kidney stone will pace the floor, unable to find a comfortable position.

The pain of an acute peptic ulcer may be relieved by food or antacids, whereas pain from acute cholecystitis or pancreatitis may be exacerbated by food.

Previous illnesses. A history of disease in other body systems may be very useful.

Urinary tract. Symptoms such as dysuria, hematuria, or changes in urinary habits should be sought.

Reproductive tract in the female patient. The patient should be asked about past or present vaginal discharge, dysmenorrhea, a history of pelvic inflammatory disease, time of last menstrual period, and so forth.

Cardiovascular system. Atrial fibrillation of recent onset or digitalis therapy might suggest intestinal ischemia.

Diabetes mellitus is associated with sepsis. Poorly controlled blood sugars in a previously

well-controlled diabetic may indicate infection.

C

Physical examination of the patient with acute abdominal pain should yield new information that reinforces impressions obtained from the history. As with the history, there are both specific and nonspecific findings.

Complete physical examination must be performed so that an important related or unrelated extraabdominal diagnosis will not be missed. Points requiring particular attention include the following:

Changes in vital signs, particularly fever, tachypnea, hypotension, or cardiac rhythm irregularities

Inspection for jaundice, dehydration, feculent breath, pneumonia, or mental disorientation or obtundation

Examination of the extremities for loss of pulses

Abdominal examination

Overall inspection

A distended abdomen with visible peristalsis suggests small bowel obstruction.

In a thin and muscular patient, prominent muscle guarding or rigidity may be visible, particularly if localized to one area of the abdomen.

A scaphoid abdomen may suggest herniation of the abdominal contents through the diaphragm and into the thoracic cavity, especially after blunt abdominal trauma.

Hernias are frequently visible, particularly when the patient is standing.

Palpation of the abdomen should be done gently and should begin away from the area of maximum tenderness.

The inguinal area should be examined for hernias or inflammatory conditions.

The abdomen should be examined to determine the points of maximum tenderness or the presence of referred tenderness. Rebound tenderness is tenderness that occurs when the examining hand is quickly removed from the abdominal wall. It is indicative of acute peritoneal irritation.

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Spasm is determined by gently depressing the abdominal wall muscles.

Comparing two areas simultaneously allows the examiner to distinguish an abnormal area from a normal one.

A spasm is voluntary if the patient is tensing the muscle in response to pain and involuntary if the muscle is taut secondary to the underlying inflammatory process.

Palpation for abdominal masses should be done systematically. A mass in a particular abdominal quadrant suggests a specific diagnosis.

Right upper quadrant: Acute cholecystitis or a complication of this diagnosis, such as

subhepatic or intrahepatic abscess

Left lower quadrant: Acute diverticulitis or peridiverticular abscess

Right lower quadrant: Acute appendicitis or appendiceal abscess

Left upper quadrant (uncommon in the acute abdomen): Complication of gastric or colonic malignancy, subphrenic abscess, or some acute inflammatory process related to the spleen, such as infarction

Midabdominal area: Pancreatic malignancy or abscess, complication of a perforated ulcer, or leaking abdominal aortic aneurysm

Percussion of the abdomen

Percussion is useful because it confirms areas of maximum tenderness and the presence of rebound tenderness.

On rare occasions, the hollow sound of tympany indicates free intraperitoneal air, but it usually is present because of air in the intestine.

A large area of tympany in the left upper quadrant suggests acute gastric dilation, a condition that can cause reflex hypotension through vagal pathways.

Auscultation is useful in many acute abdominal problems.

A silent abdomen indicates the absence of peristalsis, suggesting diffuse peritonitis, which occurs with major abdominal sepsis, intestinal ischemia or gangrene, or prolonged (longer than 3 days) mechanical obstruction with marked distention of the bowel. Absent peristalsis may also indicate an ileus resulting from some other process, such as pneumonia, a renal stone, or trauma.

Intermittent peristaltic rushes that have a crescendo followed by silence suggest an intestinal obstruction. This sign is particularly useful when the peristaltic rush coincides with the onset of episodic abdominal pain. Certain nonsurgical inflammatory conditions, such as gastroenteritis, produce high -pitched intermittent peristaltic rushes. The pain pattern is usually not synchronous with the rushes.

Rectal examination should be performed routinely in patients with acute abdominal pain.

Rectal palpation may localize the tenderness. In acute appendicitis , if the patient's appendix is located in the pelvis, the only physical finding may be a right pelvic tenderness found on rectal examination.

The presence of blood in the stool suggests either a malignancy, hemorrhoids, or an acute inflammatory GI process, such as an ulcer or colitis.

A mass palpable on rectal examination may be a pelvic abscess secondary to a perforated viscus, a sign of pelvic inflammatory disease, or a metastatic malignancy.

Acute prostatitis in men is diagnosed rectally even though it may present with vague abdominal pain. Rectal examination reveals a tender, sometimes warm prostate gland.

Gynecologic examination should be performed in all women and girls with abdominal pain. (The patient's

bladder should be empty.)

Cervical or parauterine tenderness suggests pelvic inflammatory disease.

A uterine, ovarian, or pelvic mass suggests:

Intrauterine pregnancy

Ectopic pregnancy with rupture and hemorrhage

Pelvic, ovarian, or tubal inflammatory disease with or without abscess formation

Pelvic or gynecologic malignancy

Cervical discharge should be examined microscopically for gonococci.

Examination of the genitalia should be performed in all men and boys. Torsion of the testicle, a urologic emergency, may present as sudden onset of lower quadrant or scrotal tenderness.

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Special signs are useful in diagnosing acute abdominal pain.

Tenderness to percussion over the liver or kidney suggests acute hepatitis or pyelonephritis.

Iliopsoas sign is pain in the lower abdomen and psoas region that is elicited when the thigh is flexed against resistance. It suggests that an inflammatory process, such as appendicitis or perinephric abscess, is in contact with the psoas muscle. Patients may also limp while walking and may lie with the ipsilateral hip flexed to minimize psoas muscle use.

Obturator sign is pain elicited when the thigh is flexed and then rotated internally and externally. It suggests an inflammatory process in the region of the obturator muscle, such as an obturator hernia.

Murphy's sign is elicited by palpating the right upper quadrant during inspiration: As the gallbladder descends during inspiration, acute pain is elicited, and inspiration halts. It suggests acute cholecystitis.

Cough tenderness occurs in the area of maximum tenderness when the patient coughs. The tenderness may also be elicited by shaking the patient or by any other sudden jarring movement.

Ecchymosis in the flank, periumbilical region, or back suggests a retroperitoneal hemorrhage. Possible causes include trauma, acute hemorrhagic pancreatitis, a leaking abdominal aortic aneurysm, and intestinal gangrene.

Subcutaneous, subfascial, or pelvic crepitus suggests a rapidly spreading gas -forming infection. These infections must be rapidly diagnosed and explored surgically if they are to be cured.

D Medical illnesses that can cause an acute abdomen

Life -threatening medical illness, such as lower lobe pneumonias, acute myocardial infarction, diabetic ketoacidosis, and acute hepatitis, should be sought.

Acute polyserositis (occurring with collagen vascular diseases), rheumatic fever, porphyria, and chronic lead intoxication are uncommon causes of acute abdominal pain that can be exceedingly difficult to diagnose

preoperatively. A careful history and physical examination may, however, raise them as possibilities.

Musculoskeletal problems, particularly vertebral compression of abdominal wall nerves, can also mimic acute general surgical conditions.

A high index of suspicion is necessary for acute abdominal emergencies in immunosuppressed patients (i.e., transplantation or steroid -dependent patients), whose symptoms and findings may be minimal.

E Laboratory tests provide important information in many diseases

Complete blood count

A red cell count may reveal anemia or suggest hemoconcentration secondary to dehydration.

A white cell differential count is usually shifted to the left.

Leukocytosis in the 20,000–40,000 range suggests a major septic process in need of rapid surgical intervention. However, the white cell count may be misleading. For example, a normal white cell count in an elderly or diabetic patient may in fact accompany a major septic episode because advanced age can bring on an inability to generate a leukocytosis.

Profound leukopenia, particularly with a lymphocytic predominance, suggests a viral illness.

Other conditions, such as leukemia or lead intoxication, may also be diagnosed from the complete blood count.

Urine examination generally rules out urinary tract infection or kidney stone disease. Pelvic inflammatory processes in contact with the ureter or bladder may produce a few white cells and red cells in the urine. If there is doubt, intravenous pyelography or computed tomography should be performed prior to surgery.

Serum amylase should be measured in all patients with acute abdominal pain. In general, if the level is high, it usually indicates acute pancreatitis, although other surgical illnesses, such as mesenteric thrombosis and perforated ulcer, should not be overlooked.

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Arterial blood gases may be very helpful in identifying a profound metabolic acidosis. This suggests either septic shock or severely ischemic or necrotic tissue, which indicates the necessity for surgery if no other obvious cause, such as diabetic ketoacidosis, can be found.

Serum electrolytes, serum creatinine, coagulation profile, and liver function tests are other studies that are often obtained.

A urine or serum beta-HCG should be sent in all women of child -bearing potential.

F Radiographic studies

Upright chest radiograph and flat and upright radiograph of the abdomen should be obtained in most cases of acute abdominal pain. A chest radiograph is essential to rule out other diseases, such as pneumonia, that can mimic conditions associated with an acute abdomen. Additionally, a chest radiograph is superior to an abdominal radiograph in showing intraperitoneal free air below the diaphragm. A CT scan is sensitive for free air and also provides additional information if the diagnosis is in doubt.

Bony structure abnormalities , such as fractures or metastatic lesions, may provide important diagnostic information in trauma or malignant disease.