Page 1462 - Hall et al (2015) Principles of Critical Care-McGraw-Hill

CHAPTER 104: Jaundice, Diarrhea, Obstruction, and Pseudoobstruction 1001

fat amounts, promoting enteral nutrition, treating bacterial over- should be considered in the setting of persistent diarrhea, patients with a
growth, and discontinuation of TPN altogether. 25 history of travel to a high risk area, and immunocompromised patients. 36
Medications are another cause of diarrhea by a variety of mecha-
Postsurgical, Trauma, and Other: Jaundice is a common postoperative nisms. Antibiotics are frequently associated with diarrhea by altering
complication of surgery, most commonly occurring in cardiac surgery, the colonic flora, and laxatives and prokinetics increase intestinal
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hepatobiliary surgery including liver transplantation, and surgery motility. Acid-suppressive medications also have an inherent propensity
complicated by, or for the treatment, of sepsis. Not unexpectedly, to cause diarrhea (up to 7% of proton-pump inhibitors) and many oral
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hepatobiliary and pancreatic surgeries are associated with multiple electrolyte formulations or antacids are known irritants to the gastroin-
potential complications (vascular thrombosis, strictures, leaks, hepatic testinal mucosa (magnesium, phosphates). A study of 27 ICU patients
insufficiency), and thus in such patients, early surgical consultation treated for constipation showed 70% of them subsequently developed
is advised. 28,29 diarrhea, and another study showed diarrhea resolved in over 25% of
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Bile leakage into the peritoneal cavity may be reabsorbed by the patients following the discontinuation of laxative therapy. Many oral
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peritoneal lining and manifest as hyperbilirubinemia, such as in a medications are hyperosmolar and/or contain sorbitol which can cause
post-laparoscopic cholecystectomy missed bile duct injury, perforated GI intolerance especially when given in large volumes. Sorbitol is a sugar
acalculous cholecystitis, or severe liver trauma. Another interesting but alcohol that is used as a sweetener in many oral liquid medications and
rare cause of jaundice in postoperative or trauma patients is hematobilia is known to cause osmotic diarrhea and cramping when ingested in
which often presents as jaundice, severe right upper quadrant pain, and amounts over 10 to 20 g in healthy volunteers. The amount of sorbitol
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melena. Hemolysis can also occur in the postoperative setting espe- is often not specified on medication labels as it is an inactive ingredient,
cially in patients who received large amounts of red blood cell transfu- and thus the amount of sorbitol being delivered to a patient is often dif-
sions, those with hemoglobinopathies including sickle cell disease, and ficult to determine.
those susceptible to any pro-oxidant medications (eg, patients with
glucose-6-phosphate dehydrogenase deficiency) that may have been ■
given perioperatively. MANAGEMENT OF DIARRHEA IN CRITICAL CARE
Severe hypotension and ischemia can also produce a condition Fluid and electrolyte repletion is an important initial therapy as large-
termed “shock liver” with a clinical pattern of a rapid rise in serum volume diarrhea can quickly lead to significant fluid, electrolyte, and
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aminotransferases to levels 10 to 100 times the upper limit of normal, acid-base disturbances; repletion should be accomplished via the intra-
along with delayed and less significant rises in bilirubin. Levels subse- venous route until the etiology of the diarrhea is determined.
quently plateau within a few days and the fall steadily with return to The patient’s medication list should be examined for causative agents
normal levels. Gilbert syndrome, characterized by a relative deficiency and these should be discontinued or substituted with alternative medica-
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of hepatic UDP-glucuronyl transferase, may also become unmasked by tions or routes of administration when appropriate. Sorbitol-containing
the stress of surgery or infection and a self-limited asymptomatic rise liquid medications should be discontinued and sorbitol-free formula-
in bilirubin may occur. There are also many drugs that can cause injury tions or crushed tablets used when available. Dilution of any necessary
to the liver and an examination of the patient’s medications and doses, hyperosmolar medications should be considered. 41,42
including any herbal or recreational agents used, is important when Antimotility and antidiarrheal agents should be reserved for those
searching for an etiology of jaundice. patients whose diarrhea persists despite the identification and treatment
of the underlying cause. C difficile infection should specifically be ruled
DIARRHEA out as antimotility agents in this setting can precipitate the develop-
ment of a toxic megacolon. Antimotility agents include loperamide,
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■ INTRODUCTION diphenoxylate/atropine, and oral narcotic derivatives. Loperamide is
The occurrence of gastrointestinal complications in the critically ill advocated as the medication of choice as it has the lowest risk of central
nervous system adverse effects. Bismuth subsalicylate is less effective
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patient is common. A multicenter study of 400 patients conducted in than loperamide and lacks supporting data to recommend its use.
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Spain in 1999 found that diarrhea complicated 15% of patients admitted Cholestyramine is effective in the treatment of diarrhea caused by bile
to the ICU. A similar study of over 1300 ICU patients published 10 years acid malabsorption (eg, patients with short bowel syndrome, terminal
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later reported a 14% incidence of diarrhea. The occurrence of diarrhea ileum resection, postcholecystectomy) but given concerns about binding
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continues to complicate the care of ICU patients and its management is to other medications—most notably oral vancomycin —and the lack of
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an ongoing challenge, especially in the face of recommendations for ear- data outside of these specific patient populations, its general application
lier and more aggressive enteral feeding. 34,35 This section will discuss the is not recommended.
approach and management to diarrhea that develops in the critical care The composition of enteral nutrition formulas (ENF) can also be
patient, followed by a separate discussion of Clostridium difficile. responsible for diarrhea and modification of these components can
■ CAUSES OF DIARRHEA IN CRITICAL CARE bring resolution. ENF with high osmolality may cause diarrhea,
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especially when being fed directly into the small bowel, and changing
While diarrhea can be classified into osmotic, secretory, infectious, or to a lower osmolality formula may alleviate diarrhea. 46,47 Some ENF
noninfectious, the causes of diarrhea in the critically ill patient can be may contain poorly absorbed and rapidly fermentable short-chain
simplified to those due to infection, medication, oral or enteral feeds, carbohydrates collectively termed FODMAPs (fermentable, oligo-, di-,
or preexisting intestinal disorders of absorption or motility. Most diar- monosaccharides, and polyols). 41,48 These act similarly to undigested
rhea in the ICU is acute in onset (<14 days) as opposed to persistent lactose and include fructooligosaccharides (FOS), galactooligosaccha-
≥14 days or chronic ≥4 weeks. Infection must always be considered rides (GOS), and fructose. FODMAPs significantly increase output from
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and ruled out in any new-onset diarrhea (see Fig. 104-4 and Tables 104-3 the small bowel due to osmotic effects and present rapidly fermentable
and 104-4). A careful history including any collateral information from substrates to colonic bacteria with subsequent excessive and ongoing gas
the patient’s family or close associates may reveal a preexisting condition production. Dietary FODMAPs have even been shown to induce symp-
such as lactose intolerance, celiac disease, inflammatory bowel disease, toms in healthy volunteers, 49,50 and their role in intestinal dysmotility in
or irritable bowel syndrome. Investigation generally involves fecal speci- the ICU is an area of active research.
men analysis for common bacterial and viral pathogens, and assessment Fiber is also often incorporated into the ENF or be added as a supple-
for the presence of fecal toxins when infection with C difficile or entero- ment. Fiber can be classified as soluble or insoluble, and each has different
toxigenic/enterohemorrhagic bacteria is suspected. Routine testing for effects. Soluble fibers, typically found in fruits and vegetables (eg, partially
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ova and parasites is not cost-effective for the majority of patients, but hydrolyzed guar gum, fructooligosaccharides, pectin, inulin, psyllium), are
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