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.
GI gas pattern. Air is commonly present in the stomach and colon. However, air in the small intestine
is abnormal and suggests an intra -abdominal process.
Paralytic ileus (see II B )
Air that is evenly distributed throughout the small and large intestine usually signifies paralysis of the bowel secondary to a process that is not primarily surgical.
Ileus may be localized to a specific area, such as the “sentinel” loop , an area of localized duodenal ileus adjacent to the pancreas in acute pancreatitis.
Acute gastric dilation is indicated by a markedly dilated gastric bubble. (This condition can result in severe abdominal pain and vasovagal hypotension but is easily treated by nasogastric tube decompression.)
Mechanical obstruction of the intestine (see II A ) is revealed by the presence of distended airand fluid -filled loops of bowel proximal to the obstruction and decompressed intestine distally. This air may be absent in the distal tract, particularly the rectum, unless air has been introduced by an enema given in the past 24 hours.
Mechanical bowel obstruction is an important diagnosis because it may be associated with strangulation of the bowel with resultant ischemia and necrosis. When both ends of a loop of bowel are obstructed, such as occurs with a volvulus, this is termed a closed loop obstruction and represents a surgical emergency due to the high risk of rupture and generalized peritonitis.
Postoperative adhesions, carcinoma of the colon, and inguinal hernias are the three most common causes of bowel obstruction. Specific causes may be diagnosed by the intestinal gas pattern.
Hernias may result in intestinal air located in a nonanatomic location. For example, an inguinal hernia may show gas -filled intestine extended below the inguinal ligament.
Volvulus is a segment of bowel that has twisted upon itself, resulting in both mechanical obstruction and vascular compromise. It may appear on the plain film as an isolated distended loop of bowel with tapered (“bird -beak”) margins. A sigmoid volvulus is treated by sigmoidoscopy and decompression. Other types of volvulus are treated operatively.
An ischemic or gangrenous bowel may produce few radiologic findings. If the colon is affected, however, the mucosal edema may be seen as “thumbprinting” on the wall of a dilated colon.
Isolated distention of the colon by large amounts of air may be seen on radiograph. It may be due to any of the acute processes, such as distal colonic obstruction, which may be secondary to malignancy, profound constipation, stricture, or volvulus; “toxic megacolon,” a massive colonic dilation that is associated with acute colitis; and colonic ileus , a condition of obscure etiology that results in marked distention of the cecum. If the cecum enlarges past 10–12 cm in diameter, there is a significant risk of perforation.
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Abnormal air collections outside the intestinal lumen
Free air within the peritoneal cavity signals a perforation of a hollow viscus and indicates a surgical emergency.
It is present in about 80% of gastroduodenal perforations but in fewer than 25% of colonic perforations.
Free peritoneal air is rarely secondary to other causes. However, it may be present in patients undergoing peritoneal dialysis and for up to 1 week after a laparotomy.
Air collections within the wall of the colon, a condition termed pneumatosis cystoides intestinalis, generally indicate an isolated, walled -off intestinal perforation.
Air stippling within soft tissue structures may indicate the dissection of air into the tissues from a thoracic source, such as a pneumothorax. It may, however, be due to a rapidly progressive, catastrophic gas -forming infection (see Chapter 2, V ), which is a true surgical emergency.
Air-fluid level outside the intestinal tract is associated with a subphrenic or subhepatic abscess.
Air within the biliary tree indicates an abnormal communication between the biliary tree and the intestinal tract. Causes include:
A surgical connection created to provide biliary drainage (e.g., choledochoduodenostomy)
A gas -forming infection within the biliary tree (cholangitis). Cholangitis is associated with biliary obstruction and should be treated with antibiotics followed closely by endoscopic retrograde cholangiopancreatography (ERCP) and sphincterotomy to drain the biliary tract.
Large gallstones, particularly in the elderly, which can erode into the adjacent intestine (usually the duodenum), allowing air to enter the biliary tract and the gallstone to enter the bowel. Usually, this produces transient symptoms initially, until several days later when the gallstone impacts upon and obstructs the distal ileum, producing small bowel obstruction (gallstone ileus).
Air within the portal vein is seen when a gas -forming infection affects the portal system (pylephlebitis). The infection usually derives from necrotic tissue, particularly from the small intestine, appendix, or left colon.
Abnormal calcifications
Renal stones are calcified in up to 85% of cases and appear along the path of the ureter.
Fecaliths (calcified material within the appendix) are strong evidence for acute appendicitis in patients with abdominal pain.
Pancreatic calcification suggests chronic pancreatitis.
Gallstones are calcified in 15% of cases.
Heavily calcified vessels may be present in mesenteric ischemia.
Masses , such as teratomas or malignant neoplasms, may calcify.
Soft tissue shadows
Peritoneal fat lines and psoas muscle shadows may be lost in rapidly spreading infections, hematomas, or abscesses.
Margins of solid organs (liver, kidney, or spleen) may be displaced from their normal locations by an abnormal mass.
A distended bladder may be visible and may be responsible for marked abdominal pain.
Contrast roentgenography can be highly useful in patients with an acute abdominal process that remains undiagnosed after other studies.
Intravenous pyelogram (IVP) should be obtained if a renal stone is suspected. It is also useful in identifying acute pyelonephritis, perinephric abscess, or renal infarction. When a patient suspected of having appendicitis has microscopic hematuria, the IVP is particularly useful for verifying that the hematuria is due to the periappendiceal inflammation rather than to a renal stone.
Barium swallow is helpful if it is suspected that the patient's esophagus has ruptured during a violent episode of vomiting. Known as Boerhaave's syndrome , this unusual accident may result in a left pleural effusion, which communicates with the esophageal rent, as demonstrated by the barium swallow.
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Upper GI series, using diatrizoate meglumine (Gastrografin), a water -soluble radiopaque dye, should be performed if a perforation of the stomach or duodenum is suspected but cannot be proven because free air is not visible on the plain film.
Placing contrast materials into the colon and rectum should be done very cautiously when an inflammatory condition or a perforation is suspected because even a small increase in pressure could easily convert friable tissue into a frank perforation.
This procedure is best used when the diagnosis of colon perforation is suspected and especially in a patient taking anti -inflammatory or immunosuppressive drugs, particularly corticosteroids.
In such cases, diatrizoate meglumine should be used because barium sulfate, when it mixes with stool and detritus from an infection, becomes firmly attached to the peritoneal cavity. Extensive abscess formation results, even after the surgeon attempts to irrigate the area thoroughly.
Small bowel follow-through contrast study tracks the barium through the small intestine after an upper GI series. It is useful in identifying a point of small bowel obstruction when either the history, the physical examination, or plain radiography fails to verify the diagnosis of small bowel obstruction.
G
Abdominal ultrasonography is usually of little diagnostic value in the patient with abdominal distention and severe pain, but it can be helpful when acute cholecystitis, cholelithiasis, biliary obstruction, or an abscess is suspected. Computed tomography may also be helpful, but is generally reserved for the patient whose condition
remains undiagnosed after other studies have been exhausted. Some have advocated its use to assist in the diagnosis of acute appendicitis.
H
General principles used in the approach to the patient with acute abdominal pain are discussed below.
A careful and systematic evaluation of the patient should be routinely performed. Most patients will have a well-documented diagnosis if this principle is followed.
Statistically speaking, certain diagnoses are very common , such as appendicitis and gastroenteritis, whereas other diagnoses are quite rare, such as pylephlebitis. The physician should not search for an occult diagnosis when a common diagnosis is more likely to be correct.
When the diagnosis is not initially clear, continued observation and repeated blood studies (complete blood count, arterial blood gases, amylase, and electrolytes) may lead to the correct diagnosis as the disease process evolves.
Although this practice might be desirable in a patient with gastroenteritis, delay can be catastrophic in acute appendicitis, ischemic bowel, small bowel obstruction, volvulus, or incarcerated hernia.
If the diagnosis is not certain but the patient may have a potentially lethal condition that could be cured by an early operation, then an early operation should be performed—i.e., a small percentage of negative laparotomies are justified in patients with acute abdomen. This premise is best illustrated by the case of a patient with acute appendicitis. Here, a policy of watchful waiting may convert a simple appendicitis into a perforated appendicitis with generalized peritonitis and septic shock. The risk of death from this complication is many times higher than the risk from a small right lower quadrant incision in a patient who proves to have a normal appendix and mesenteric adenitis.
Analgesics, particularly narcotics, should be withheld from the patient until the diagnosis is established or until the decision to proceed to surgery has been made. Serial physical examinations will be totally useless if the patient has been given narcotics.
Antibiotics should also be withheld until a diagnosis has been made and the antibiotic therapy is needed. The only exception to this is the patient who presents in septic shock from an unknown cause. In that situation, broad-spectrum antibiotics should be part of the patient's resuscitation.
Fluid deficits and electrolyte imbalances should be corrected before surgery. The few exceptions are:
Conditions that threaten immediate exsanguination, such as a ruptured abdominal aortic aneurysm
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Conditions in which the fluid or electrolyte abnormality cannot be corrected in a reasonable amount of time—i.e., conditions that cause profound acidosis, such as necrotic bowel, where the acidosis cannot be corrected until the bowel is surgically removed
Nasogastric tubes should be placed before the induction of anesthesia to empty the stomach, thus minimizing the risk of pulmonary aspiration.
II Intestinal Obstruction
The normal flow of intestinal contents can be blocked by a mechanical obstruction or by a functional obstruction that occurs because of impaired intestinal motility. An acute abdomen often ensues.
A
Mechanical obstructions are common and have various benign and malignant causes. If not treated expeditiously (usually by surgical removal of the cause), mechanical obstructions can rapidly become lethal. Acute obstruction
occurs over hours to days and has a rapidly evolving course, whereas chronic obstruction may have a slow course with malnutrition, constipation, and other signs of chronic illness.
Types
Simple obstruction. There are no complicating factors, such as ischemia or perforation.
Strangulating obstruction. The blood supply to the involved segment of bowel is significantly impaired. The ischemia may result from a twisting of the intestinal blood supply upon itself (volvulus) or from a constriction of the blood flow by a tight band or hernial opening.
Closed loop obstruction. Both limbs of the bowel are obstructed; therefore, gas and liquid cannot pass in either direction.
Intussusception. The bowel invaginates itself, causing a narrowing of the lumen and subsequent obstruction. It may result from either viral infections or intraluminal polypoid tumors.
Perforating obstruction. The bowel proximal to the obstruction overdistends and perforates. The most common area of perforation when the colon is obstructed is the cecum.
Causes (Table 9-1)
Intestinal adhesions are the most common cause of obstruction.
They may result from a previous surgical exploration, particularly when talc was used to lubricate the surgeon's gloves, or their etiology may be obscure.
They may be diffuse, involving all peritoneal structures, or solitary, blocking only one area of the intestine.
Hernias (see Chapter 2 III and Chapter 29 II) are a second very common cause of intestinal obstruction. A segment of intestine migrates through a defect in the abdominal wall (external hernia) or through a mesenteric or omental defect (internal hernia) and becomes blocked by the narrow ring that is present at the peritoneal communication of the hernia.
TABLE 9-1 Causes of Bowel Obstruction
Type of ObstructionExamples
Mechanical Impaction
Lesions |
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Extrinsic |
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Adhesions |
Previous surgery |
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Hernia |
Incarcerated femoral hernia |
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Intrinsic |
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Congenital |
Meckel's diverticulum |
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Inflammatory |
Diverticulitis |
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Malignant |
Sigmoid cancer |
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Masses |
Ovarian cancer |
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Volvulus |
Sigmoid or cecal |
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|
Radiation injury |
Previous gynecologic malignancy |
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|
|
|
|
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Intestinal tumors are the third most common cause of obstruction. The most common obstructing tumor is an adenocarcinoma of the colon or rectum. Benign lesions of the small bowel and colon, such as lipomas, can become the leading point of an intussusception. Other malignant tumors, such as carcinoid or lymphoma, can obstruct the intestinal lumen.
Other intrinsic lesions within the bowel wall or the lumen can cause acute obstruction.
Congenital lesions: webs, malrotations, and atresias
Inflammatory lesions: Crohn's disease, diverticulitis, ulcerative colitis, and infections such as tuberculosis
Luminal foreign bodies: bezoars, parasites, and gallstones
Radiation injury, other trauma , or endometriosis
Other extrinsic lesions , such as large intra -abdominal tumors or abscesses, can compress the intestinal lumen.
Treatment
Intestinal adhesions are treated by surgical lysis of the obstructing bands if the obstruction does not resolve in several days.
Hernias are treated by a reduction of the contents of the hernia and subsequent repair. The bowel must always be examined for necrosis.
Intestinal tumors are treated by surgical removal.
Treatment of intrinsic and extrinsic lesions depend on the lesion.
B
Functional obstructions are blockages in the intestinal flow that result from impaired motility (paralytic or adynamic ileus ). These are usually treated by observation and by fluid and nutritional support until the causal agent resolves. Possible causes include:
Direct irritation of the intestine , such as generalized peritonitis. Irritation may also be a factor in the postoperative adynamic ileus that can last for 3–7 days following surgery.
Extraperitoneal causes, such as retroperitoneal hematoma or nerve root compression. Retroperitoneal dissections, such as a nephrectomy or sympathectomy, can cause a prolonged ileus.
III Upper Gastrointestinal Hemorrhage
A
Causes of massive upper GI hemorrhage as shown by endoscopy are given in Table 9-2.
B Types of bleeding
The diagnosis of hemorrhage is generally obvious, but locating the site of bleeding may be difficult. The type of GI bleeding may give a clue to its source.
Hematemesis is the vomiting of blood that is either bright red or resembling coffee grounds in appearance. Hematemesis usually indicates a bleeding source proximal to the ligament of Treitz. Coffee -grounds hematemesis indicates that the blood has been in contact with gastric acid long enough to become converted from hemoglobin to methemoglobin.
Hematochezia is the passage of bright red blood by rectum. Although it indicates GI bleeding, it does not specify the level within the GI tract.
Melena is the passage of black, usually tarry, stools. Although melena signifies a longer time within the GI tract than bright red blood, it does not guarantee that the bleeding is from the upper tract.
TABLE 9-2 Causes of Upper Gastrointestinal Hemorrhage
Duodenal ulcer
Gastric ulcer
Diffuse erosive gastritis
Esophageal or gastric varices
Mallory-Weiss tear of the gastroesophageal junction
Gastric carcinoma
Arteriovenous malformations
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Blood mixed with stool and mucus can produce a characteristic jellylike or “currant -jelly” stool. This may originate from a Meckel's diverticulum, particularly in children.
C History
The history should include information about previous episodes of GI bleeding, current medications (e.g., aspirin or warfarin use), and related diseases (e.g., hematologic disorders, alcoholism, peptic ulcer disease, and recent episodes of vomiting).
D
Physical examination should specifically include a search for evidence of nasopharyngeal bleeding, portal hypertension, weight loss, malignancy, or systemic diseases such as chronic hepatic or renal failure.
E Diagnosis
The cause and the location of the bleeding must be confirmed unless imminent exsanguination calls for immediate measures (see Chapter 21, I D 3 e [3] [f] ). In less urgent circumstances, once the patient has been stabilized, one
may continue with diagnostic procedures.
Fiberoptic endoscopy of the upper GI tract has become the optimal diagnostic procedure because it allows direct visualization of the lesion in over 80% of cases.
Endoscopy allows:
Determination of the size and number of lesions in most cases (lesions are multiple in 15% of cases)
Assessment of which site is actively bleeding
Assessment of the rate of bleeding. For example, if an arterial vessel is visibly bleeding in the base of a large duodenal ulcer, then there is a good chance that it will not stop bleeding.
Distinction between an ulcer, varices, gastritis, and a tear in the esophagus (Mallory-Weiss syndrome) that follows forceful vomiting
Determination of whether a lesion is benign or malignant
Endoscopy is only safe if the patient's vital signs are relatively stable. Sedation is dangerous because it increases the risk of vomiting followed by aspiration of the gastric contents into the pulmonary bed.
Upper GI series helps to define anatomy or pathology more completely, but unfortunately, it sheds little light on the relationship of a particular lesion to the hemorrhage.
Passage of a nasogastric tube aids considerably in determining that the source of bleeding is proximal to the ligament of Treitz.
Angiography and radionuclide scanning may occasionally help to locate the site of bleeding, but both procedures are more useful in lower GI hemorrhage.
F Treatment
If treated expeditiously in a systematic fashion, the patient with upper GI hemorrhage has an excellent chance for recovery. Treatment is aimed at supporting the patient's vital signs as well as stopping the hemorrhage. Resuscitation measures should begin immediately when the patient is first seen.
Medical treatment of aggravating factors can then begin.
A nasogastric tube is inserted, and the residual thrombus in the stomach is removed with an iced saline solution.
Clotting factors. Any clotting abnormalities are corrected with appropriate factors (see Chapter 1, III C 2).
Fresh frozen plasma if the prothrombin time is abnormal
Platelets if thrombocytopenia is present
Vitamin K if bleeding is from esophageal varices
Histamine 2 (H2 ) antagonists, proton pump inhibitors (PPI), and antacids. An aggressive regimen is begun. H2 antagonists given as a continuous infusion are commonly used in this setting. Oral
antacids with gastric pH monitoring also have been used.
Vasopressin , a powerful vasoconstrictor, may be useful.
It can be infused through a peripheral vein at a rate of up to 1 U/minute, or it can be infused directly into the bleeding vessel by means of angiography.
Vasopressin temporarily controls bleeding in 75% of patients; by contrast, bleeding was stopped in 30% of patients treated conventionally without vasopressin. However,
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vasopressin is contraindicated in patients with significant coronary artery disease because of coronary vasoconstriction.
Fiberoptic endoscopy , in addition to being a diagnostic procedure, may also be useful when esophageal varices are to be sclerosed (see Chapter 14, II E ) or small bleeding sites are to be coagulated.
Angiography similarly may be a therapeutic aid. It allows bleeding from small vessels to be controlled either by embolization of the bleeding vessel or by intra -arterial administration of vasopressin.
Balloon tamponade (see Chapter 14, II E 3 d) can be important in controlling bleeding from varices.
Surgical treatment. The type of surgery performed is discussed in Chapter 11 .
The patient's cardiovascular status, as well as the amount and duration of bleeding, is particularly important. For example, a patient with heart disease may tolerate continued bleeding poorly and thus may need early surgery.
Only about 10% of patients will require surgery.
Indications for surgery are as follows:
Exsanguinating hemorrhage. A patient with uncontrollable hemorrhage who is losing blood faster than it can be replaced must be sent to the operating room immediately for control of the site of bleeding.
Profuse bleeding , especially in association with hypotension. Patients should be treated surgically:
If more than 4 U of blood are required for initial resuscitation
If bleeding continues at a rate of more than 1 U every 8 hours
If a brief hypotensive episode could have catastrophic results, as in patients with coronary artery disease or cerebrovascular disease or in patients older than 60 years of age
Continued hemorrhage despite resuscitation and other treatment
The mortality rate of upper GI bleeding is low among patients who need less than 6–7 U of blood.
The rate increases dramatically with requirements above 7 U. Thus, surgery should be undertaken before the blood loss reaches that point.
Recurrent bleeding after its initial cessation. About one fourth of patients rebleed, and the mortality rate for these patients is as high as 30%, in contrast to a mortality rate of approximately 3% among patients who do not rebleed.
Pathologic features of the bleeding site that increase the risk of recurrent bleeding include:
A posterior duodenal ulcer with the gastroduodenal artery visible in its base
A giant gastric ulcer
Special situations may call for a modification of the usual routines of management.
A patient with a rare or hard -to -find blood type should be operated on while blood is still available.
A patient who refuses blood transfusion for any reason should undergo surgical exploration early.
A patient with a coagulopathy should have the disorder corrected, if possible, prior to surgical exploration.
G Prognosis
The prognosis for patients who are bleeding from a source other than esophageal varices is as follows:
Some 25%–50% will have a recurrence of bleeding during the next 5 years, and about 20% will require surgery.
The mortality rate is low (about 3%) if the bleeding stops spontaneously.
IV Lower Gastrointestinal Hemorrhage
A Overview
Acute lower GI hemorrhage is managed initially in much the same way as upper GI hemorrhage. P.190
Resuscitation with blood and intravenous fluids is begun immediately.
The history is taken, and a physical examination is performed.
Diagnostic studies are begun to identify the site and cause of the bleeding.
Vasopressin may be used as in upper GI bleeding (see III F 1 d).
B Initial studies
Anorectal examination is performed to determine if the source of bleeding is a hemorrhoid, anal fissure, anal carcinoma, or other anorectal lesion.
A bleeding site in the upper GI tract must be ruled out.
A nasogastric tube is passed to ascertain that no bleeding is present in the gastroduodenal region. On occasion, however, duodenal bleeding will not reflux into the stomach because of a closed pyloric sphincter. If bile is present, duodenal bleeding is unlikely.
Endoscopy (see III E 1) is therefore required to rule out upper GI bleeding with absolute certainty. Most physicians will withhold endoscopy when a highly probable source of the bleeding is found in the lower GI tract. However, if surgery is anticipated, particularly when one is not sure of the diagnosis, endoscopy of the upper GI tract should be performed to exclude any bleeding site there.
A bleeding site in the lower GI tract must be located. Once the upper tract has been eliminated as a source of bleeding, the lower tract should be investigated, including the distal small bowel, colon, and anorectal area (Table 9-3).
Colonoscopy should be performed.
The presence of a mass lesion, such as rectal carcinoma, is visualized in about 3% of patients with massive lower GI bleeding.
Discrete bleeding sites from ulcers or hemorrhoids may be seen.
A diffusely hemorrhagic mucosa suggests colitis, a platelet deficiency, or a hematologic disorder.
Even if no lesion is visualized, it is important to make certain that the lower 15 cm of the rectum is normal because this region is inaccessible intraperitoneally if laparotomy is necessary. Additionally, if it is normal, it gives presumptive evidence that the bleeding is coming from a more proximal site.
Anoscopy is frequently overlooked but should be routinely performed because bleeding lesions in the anal canal may be missed on sigmoidoscopy.
C
Subsequent diagnostic tests will depend on whether the bleeding stops or continues. About 75% of the patients will spontaneously stop bleeding without further intervention.
If bleeding stops , the following steps are taken.
A barium enema , a colonoscopy , or both procedures should be performed:
To identify or rule out diverticulosis or colon carcinoma
To provide indirect evidence for colonic mucosal ischemia
The patient should be monitored thereafter.
If bleeding continues, further diagnostic studies should be done to identify the source more precisely in preparation for surgery, if it becomes necessary.
TABLE 9-3 Causes of Lower Gastrointestinal Bleeding
Adults |
Children |
Anorectal disease |
Meckel's diverticulum |
|
|
Diverticular disease |
Intussusception |
|
|
Angiodysplasia |
|
|
|
Polyps
Malignancy
Inflammatory bowel disease
Ischemic colitis
P.191
If bleeding continues, a barium enema should not be performed. The residual barium in the colon may make subsequent angiography difficult or impossible.
Angiography and radionuclide scanning are useful.
Selective mesenteric angiogram will identify the bleeding site (or sites) in up to 80% of patients when the rate of bleeding exceeds 0.5 mL/minute. Angiography is also highly useful for identifying angiodysplastic lesions of the colon.
Radionuclide scan , which uses red blood cells labeled with technetium-99m (99m Tc), is sensitive enough to detect a bleeding site when the rate is as low as 0.10 mL/minute.
Colonoscopy is unsatisfactory and may be dangerous when lower GI bleeding is rapid: Visualization is poor, and there is a risk of colon perforation.
D
Indication for surgery is persistent bleeding.
The patient's cardiovascular status and amount and duration of bleeding are taken into consideration, as for upper GI hemorrhage (see III F 1, 2).
The surgical procedure is aimed at removing the underlying cause of the bleeding.
On occasion, the precise point of bleeding cannot be established.
In these instances, the stomach, duodenum, and small intestine should be carefully examined. Meckel's diverticulum, Crohn's disease, and other inflammatory or malignant lesions should not be overlooked.
A “blind” total colectomy may be necessary if no other source of the bleeding is found.
Intraoperative endoscopy of the colon, upper GI tract, and small bowel may be very useful in this setting.
The mortality rate for lower GI bleeding is currently about 10%.