Should Patients with End-Stage Liver Disease be Intubated?
Abstract & Commentary
Synopsis: Mortality among patients with advanced cirrhosis who required intubation and mechanical ventilation was related more to the derangement of liver function than to the severity of critical illness as assessed by APACHE II or SAPS.
Source: Rabe C, et al. Intensive Care Med. 2004;30(8): 1564-1571.
Critical illness, and particularly the requirement for invasive mechanical ventilation, has a very poor prognosis in patients with advanced cirrhosis (end-stage liver disease, [ESLD]) although the reasons for this are uncertain. This study examined the hypothesis that outcome among ESLD patients requiring mechanical ventilation was primarily a function of the severity of the underlying liver disease rather than the acute problem resulting in ICU admission. Rabe and colleagues at the University of Bonn retrospectively reviewed the records of 76 consecutive medical ICU admissions of patients with ESLD who required intubation and ventilatory support between 1993 and 2003. All patients admitted during this interval whose records were complete were included, although subsequent admissions of the same patient were excluded.
The 46 men and 30 women had a mean age of 55 years (range, 18-77). Gastrointestinal bleeding was the reason for ICU admission in 57% of patients, and hepatic encephalopathy in 25%. Intubation was performed for airway protection in 46%, because of respiratory failure in 38%, and for shock or other reasons in 16%. Fifty-nine percent of the patients died during the ICU stay, with the majority of deaths due to refractory shock and exsanguination. Although measures of hepatic compromise such as serum protein, bilirubin, prothrombin time, ALT, and the Child-Pugh score (class A, B, or C) were all strongly associated with mortality by univariate analysis, there was no clear relationship between severity of illness (as measured by acute physiology scores, APS) and mortality until very high APS scores (20 or higher) were reached.
Mortality in patients with Child-Pugh scores < 10 (classes A and B) was 33% (5/15), as compared with 66% (40/61) in patients with Class C. Among patients in Class C, survival was 16% among patients with initial Child-Pugh scores of 12-13, and only 8% among those with scores of 14-15. Using a modification of the TISS score to assess the intensity of nursing care and need for other ICU resources on the day of intubation, the authors found no difference in outcome between survivors and nonsurvivors. Mortality was very high even among patients who were intubated only for airway protection.
Comment by David J. Pierson, MD
This retrospective study found death among ESLD patients who required intubation and mechanical ventilation in the setting of critical illness to be related primarily to the severity of the liver disease rather than to such measures of illness severity as APACHE II score, SAPS, and resource use. Receiver-operating characteristics curves with regard to ICU outcomes showed areas under the curve of 0.87 for the Child-Pugh score, as compared to 0.66 for the APACHE II score and 0.60 for the APS, indicating that the first performed substantially better as a predictor of ICU death.
While numerous studies have documented the poor survival of ESLD patients who require intubation and mechanical ventilation, this may be the first to demonstrate that this is due much more to the underlying liver disease than to the temporal reason for ICU admission. This finding, in Rabe et al’s words, ". . .may enable clinicians to focus ICU resources on patients such as Child-Pugh A/B or mild Child-Pugh C (< 12 points). . . and not admit patients such as advanced Child-Pugh C (> 14 points) cirrhotic patients who are unlikely to benefit from ICU care." Whether ICU admission should be withheld from patients with ESLD is a murky area. However, the findings of this study may be helpful in discussing the appropriateness of continued aggressive care with ESLD patients and their families when rapid improvement does not occur in the setting of critical illness that requires invasive ventilatory support.
David J. Pierson, MD, Pulmonary and Critical Care Medicine Harborview Medical Center University of Washington, is Editor for Critical Care Alert.