Page 1475 - Hall et al (2015) Principles of Critical Care-McGraw-Hill

1014 PART 9: Gastrointestinal Disorders

is indicated for variceal hemostasis in patients with preserved hepatic absence of a predisposition to multiorgan dysfunction that exists in
synthetic function (ie, Child-Pugh A disease). Esophageal transection decompensated cirrhosis. As outlined in Table 105-1, multiple studies
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with or without devascularization may be another surgical option in pertaining to nonvariceal hemorrhage have identified clinical and
massive exsanguination refractory to other interventions. endoscopic indicators that increase the risk for continued or recurrent
Shunt operations can be divided into (1) nonselective shunts bleeding, and therefore predict an adverse prognosis. The remaining
(eg, portocaval shunts) that decompress the entire portal system and mortality rate of 10% is largely due to rebleeding in patients with these
divert all blood flow away from the portal vein and (2) selective shunts factors. The important role of early therapeutic upper endoscopy in
(eg, distal splenorenal shunt) that compartmentalize the portal tree into achieving hemostasis, reducing rebleeding, and improving short-term
a decompressed variceal system and a hypertensive superior mesenteric morbidity and mortality has been established 55,56 and reiterated in a
vein that maintains sinusoidal perfusion. A selective shunt is the pre- recent consensus statement addressing the management of nonvariceal
ferred operation because portocaval shunts significantly alter vascular bleeding. Furthermore, with regard to peptic ulcer disease, endoscopic
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anatomy and therefore complicate future liver transplant surgery. In characterization of high-risk ulcer lesions has led to the development
addition, emergency portocaval shunts are associated with a higher rate of specific endoscopic therapies that have improved hemostatic efficacy
of thrombosis and shunt failure. and outcome compared with prior medical therapy. 2
Distal splenorenal shunt was found to be similarly efficacious in the The evaluation and management of nonvariceal hemorrhage are out-
control of refractory variceal bleeding in Child-Pugh class A and B lined in Figure 105-3. Following initial hemodynamic, pulmonary, and
patients compared to TIPS. The reintervention rate was higher in the hematologic management, early upper endoscopic evaluation with thera-
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TIPS group, mainly due to TIPS occlusion. However, the TIPS used in peutic intent should be conducted. Emergent endoscopy should be pursued
this study were the older uncoated stents, which are known to occlude in the setting of hemodynamic instability that is refractory to fluid resus-
more frequently than the currently used coated stents. citation. Acid-suppression therapy in the form of proton-pump inhibi-
Distal esophageal transection in the setting of massive variceal tors is recommended prior to endoscopy to downstage the endoscopic
exsanguination may control bleeding, but mortality remains above 80%. lesion and decrease the need for endoscopic intervention. However,
Since the transection does not address the underlying portal hyper- this has no clear benefit on important outcomes such as blood transfusion,
tension, varices recur after a variable period, and rebleeding should rebleeding, need for surgery, and mortality, and therefore should be used
be anticipated. Esophageal transection with devascularization of the only as an adjunct to endoscopy. Following endoscopic hemostasis,
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gastroesophageal junction (Sugiura procedure) may be considered in intravenous high-dose proton-pump inhibitors have demonstrated
patients who have an absolute contraindication to shunt surgery, such significant benefit with regard to rebleeding, need for surgery, and
as extensive thrombosis in the portal venous circulation involving the mortality, and should be given for 72 hours as an intravenous infusion. 22,58
splenic, superior mesenteric, and portal veins. Since peptic ulcer disease accounts for the majority of nonvariceal bleeds
Variceal hemorrhage may occur in noncirrhotic patients. Patients and has been the focus of therapeutic developments, the different treat-
with extrahepatic portal hypertension are better operative shunt candi- ment modalities will be discussed in this context. The management of some
dates than cirrhotics. When large gastric varices accompanied by small nonulcer lesions, including stress-related mucosal damage, will follow.
or absent esophageal varices are identified, splenic or portal vein throm- ■
bosis should be considered as a possible etiology rather than cirrhosis. PEPTIC ULCER DISEASE
Splenic and portal vein thrombosis may occur in the setting of acute Endoscopic Therapy: Progress in endoscopic diagnosis and therapy has
pancreatitis, pancreatic cancer, abdominal trauma, and hypercoagulable been due largely to major improvements in endoscopic techniques
states. It is essential to identify this subset of patients with variceal and equipment. A number of hemostatic endoscopic methods have
hemorrhage because splenectomy rather than a portosystemic shunt been developed, but the two used most commonly in the United States
may be curative. Celiac angiography is diagnostic. are contact thermal devices and injection therapy with epinephrine.
Emerging Therapies: A new method for the control of variceal hem- Contact Thermal Devices Thermal therapy is designed to produce coagulation
orrhage was recently described in which a removable, covered, self- and dehydration in the ulcer base surrounding the bleeding vessel, and
expanding metal stent is deployed in the lower esophagus. this results in constriction and destruction of the submucosal feeding
The stent controls bleeding by tamponade of varices in the lower vessels supplying the surface artery. The two types of thermal therapy
esophagus. In the initial pilot studies, this method was found to be that have gained popularity are the bipolar probe and the heater probe.
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effective to control refractory esophageal variceal bleeding. 53,54 Further Bipolar probes heat contacted tissue by passing electricity via tissue
studies are underway to further characterize the role of such treatment water between positive and negative electrodes located at the tip of the
in the management of refractory variceal bleeding. probe. Once the contact tissue is fully desiccated, electrical conduction
ceases, and deeper tissue coagulation is restricted. On the other hand,
Secondary Prophylaxis: If successful hemostasis is achieved by any of the the heater probe uses a thermocouple at the end of the probe to generate
interventions discussed above, it is essential that secondary prophylaxis heat, and this process does not depend on tissue water. Therefore,
to prevent variceal rebleeding is initiated in the ICU. Once the hemo- deeper tissue coagulation is achievable despite desiccation, although this
dynamic status is stabilized, nonspecific β-blocker therapy (nadolol increases the risk of perforation.
20-40 mg/d) should be initiated to decrease portal hypertension. This
pharmacologic intervention should be coupled with an endoscopic vari- Endoscopic Clips Placement of endoscopic clips is a relatively new method
ceal band ligation schedule as defined by the gastroenterologist because in endoscopic treatment of bleeding peptic ulcer. The endoscopic clip is
the combination of these therapeutic modalities decreases the risk of placed directly on the visible vessel in the ulcer bed. Multiple clips can
variceal recurrence and rebleeding. In addition, the patient should be be applied to achieve hemostasis of the bleeding ulcer.
evaluated for vascular shunt procedures, including TIPS and surgical Injection Therapy Injection therapy is aimed at causing vasoconstriction and
shunts. Most importantly, early referral to a transplant center should be necrosis of the bleeding vessel and surrounding tissue. Injection with
initiated to evaluate the patient for liver transplantation. epinephrine (1 : 10,000 dilution in saline) or absolute alcohol has been
shown to be effective in achieving acute hemostasis. While epinephrine
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NONVARICEAL HEMORRHAGE exerts a vasoconstrictive effect on the vessel, pure ethanol causes dehy-
dration, contraction, and necrosis of the vessel and surrounding tissue. It
In contrast to variceal hemorrhage, nonvariceal hemorrhage presents should be noted that the rebleeding rate is high if epinephrine injection
a favorable prognosis. The improved outcome can be attributed to a therapy is performed in isolation, and therefore, it should be combined
greater than 90% spontaneous cessation rate of bleeding and to the with thermal coagulation therapy. The technique used in injection

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