Chapter 46 Gastrointestinal Bleeding in the Critically ill Patient
1 What are the anatomic definitions of upper versus lower gastrointestinal (GI) bleeding?
The GI tract is anatomically divided into upper and lower by the ligament of Treitz. Although this classification has little physiologic significance, it is important to bear in mind that bleeding originating distal to the ligament of Treitz cannot travel backward to the upper GI tract because of the acute angle of the small bowel at this site. Bleeding from the upper GI tract is far more common than in the lower, and this is particularly true in the critically ill.
2 What are hematemesis, coffee-ground emesis, hematochezia, and melena? Are these features helpful in determining the site and rate of bleeding?
Hematemesis is vomiting of fresh, red blood and indicates bleeding in the upper GI tract. Approximately 50% of patients with upper GI bleeding (UGIB) will present with hematemesis.
If the blood is older, it can appear like coffee grounds. The return of bright red blood or coffee grounds through a nasogastric tube (NGT) is highly specific for hemorrhage proximal to the ligament of Treitz.
Hematochezia is used to describe passage of bright red or maroon-colored blood through the rectum and typically indicates a lower tract source. Less commonly (< 15%) it may indicate the rapid transit of torrential hemorrhage from the upper tract.
Melena is the passage of black, tarry, and usually foul-smelling stool because of degradation of blood components as they traverse the GI tract. It typically signifies upper GI tract bleeding (70%) or, less often, hemorrhage from the proximal lower tract (30%).
3 Do all patients with GI bleeding need to be monitored in the intensive care unit (ICU)?
No, but patients with evidence of active bleeding (ongoing transfusion requirement, hemodynamic instability) or other significant comorbidities should be closely monitored in a high-acuity setting, such as an ICU.
4 What are the most common causes of upper and lower GI bleeding?
See Tables 46-1 and 46-2.
Table 46-1 Causes of Upper Gastrointestinal Bleeding
| Cause | Prevalence (%) |
|---|---|
| Peptic ulcer disease | 55 |
| Gastritis-duodenitis | 20 |
| Esophageal varices | 12 |
| Mallory-Weiss tears | 8 |
| Neoplasm | 3 |
| Angiodysplasia | 2 |
Table 46-2 Causes of Lower Gastrointestinal Bleeding
| Cause | Prevalence (%) |
|---|---|
| Diverticular disease | 40 |
| Angiodysplasia | 20 |
| Colitis | 20 |
| Anorectal bleeding (hemorrhoids, anal fissures) | 7 |
| Neoplasm | 7 |
| Small bowel bleeding | 6 |
5 What risk factors are associated with higher mortality in patients with upper GI tract hemorrhage?
6 What are the most common causes of GI tract bleeding in critically ill patients?
Although critically ill patients can have any of the usual causes of GI bleeding, they are at particular risk for development of stress-related mucosal disease (SRMD) in the upper GI tract and hypotension-induced colonic ischemia. In addition, the increasing use of rectal tubes for the management of antibiotic- and enteral feeding–associated diarrhea is associated with a rise in incidence of lower GI bleeding (LGIB) due to iatrogenic rectal fissures and ulcers.
7 What are the immediate actions that need to be taken in an acute GI tract hemorrhage in the ICU?
Ensure patient has at least two large-bore (at least 18 gauge) intravenous catheters.
Insert Foley and nasogastric catheter (if not already in place), and initiate resuscitation (with crystalloids or blood products) per the local guidelines and policies.
Consider obtaining a definitive airway in the uncooperative, agitated, or encephalopathic patient at risk for aspiration.
Aspirate sample from nasogastric tube and perform rectal examination (attempt to localize the source of bleeding).
If UGIB, initiate medical therapy with intravenous proton pump inhibitors.
If suspicious of bleeding varices, start an octreotide infusion.
Consult the endoscopy and/or radiology and surgical services as needed.
For more details on managing acute GI tract bleeding, see algorithms in Figures 46-1 to 46-3.
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