upper quadrant pain, Murphy’s sign, nausea and vomiting, abdominal distention, decreased
bowel sounds, fever, jaundice, and abdominal mass (19,21); although patients with mental
status changes often lack pain and other symptoms, absence of any one clue should not
exclude such a serious possibility (18,22).
Laboratory values suggesting the diagnosis include leukocytosis, hyperamylasemia, and
elevated aminotransferases (22). Nevertheless, these findings are nonspecific, and given the
likelihood of atypical presentation, the equivocal patient generally warrants radiologic and/or
nucleotide (isotope) tests including ultrasound, CT scan, and cholescintigraphy such as
hepatobiliary iminodiacetic acid (HIDA) scan. Of these, cholescintigraphy demonstrating an
abnormal gallbladder ejection fraction of<40% in 45 minutes has been found most accurate,
with a sensitivity of 90% to 100%, and a specificity of 88% (18,23); however, patients receiving
TPN for a prolonged period may exhibit delayed gallbladder emptying, producing a false-
positive result. CT detects roughly two-thirds of cases (18). Ultrasound, by contrast, when
searching for the typical signs of thickened gallbladder wall, sludge, pericholecystic fluid,
emphysematous change, and hydrops has recently been shown just 30% sensitive in critically
ill trauma patients (23). Finally, diagnostic laparoscopy, although invasive, is nevertheless
acceptably safe and allows direct visualization of the organ. In many cases, a combination of
studies will be necessary to secure a diagnosis (24).
Treatment
Cholecystectomy, together with antibiotics, is the definitive treatment for acalculous
cholecystitis. Laparoscopic surgery may be possible, and this being minimally invasive,
might be considered an attractive option in the critically ill patient. Surgeons, however, must
be prepared to encounter many possible complications, including the increased likelihood of
gangrene and empyema, both of which are difficult to manage laparoscopically, as well as the
tendency to encounter adhesions in any postoperative patient. For poor surgical candidates,
another treatment option is percutaneous or laparoscopic cholecystotomy. This procedure is
safe and effective in relieving sepsis, but is contraindicated in the cases of gangrene and
perforation, and of course, subject to all the limitations of laparoscopy (25). Appropriate
antibiotic treatment would center on coverage of gut flora, such asb-lactamase inhibitor
penicillin along with an anti-anaerobic agent.
Colorectal Anastomotic Leakage
Risk Factors, Prevalence, and Long-Term Sequelae
Approximately 3% to 6% of large-bowel surgical anastomoses constructed by experienced
surgeons may leak. Anastomotic breakdown is the most common cause of stricture formation
and also predisposes to increased local recurrence of cancer, a lower cancer-specific survival,
and poor colorectal function. Risk factors for anastomotic leakage include male gender,
obesity, malnutrition, cardiovascular disease and other underlying chronic disease states,
steroid use, alcohol abuse, smoking, inflammatory bowel disease, and preoperative pelvic
irradiation. Specific operations that predispose to the development of a leak include
emergency indications for surgery, low anterior resection, colorectal anastomoses, particularly
difficult or long surgeries lasting over two hours, intraoperative septic conditions, and
perioperative blood transfusions (26).
Diagnosis
The diagnosis of an anastomotic leak in the postoperative patient is relatively straightforward.
A typical triad indicative of infection includes fever, leukocytosis, and pelvic pain. Given these
signs and symptoms, together with the appropriate surgical history, anastomotic leakage
should be high on the differential diagnosis. Other clues that might prompt clinical suspicion
include absence of bowel sounds on postoperative day 4 or diarrhea before day 7, greater than
400 mL of fluid from an abdominal drain by day 3, and renal failure by day 3. Further evidence
can be gleaned from CT scan with rectal contrast that will reveal leakage of contrast with a
sensitivity of 98%, as well as any abscesses that may be present as a result. CT is reported to be
a superior modality to plain film with contrast enema, which in one review was positive in
only 54% of patients who were later determined to have anastomotic breakdown (26).
264 Wilson