WITHDRAWING LIFE-SUPPORT FROM MECHANICALLY VENTILATED RECIPIENTS OF BONE-MARROW TRANSPLANTS - A CASE FOR EVIDENCE-BASED GUIDELINES

Background: Mechanical ventilation after bone marrow transplantation i s associated with a high mortality rate. The available literature prov ides conflicting predictors of outcome in relatively small study group s. Objective: To identify predictors of death and mortality trends in mechanically ventilated transplant recipients. Design: Nested case-con trol study. Setting: The Fred Hutchinson Cancer Research Center in Sea ttle, Washington, which specializes in bone marrow transplantation. Pa tients: All survivors (cases, n = 53) and a group of patients matched for year of transplantation who did not survive (controls, n = 106) we re selected from all mechanically ventilated patients (n = 865) who re ceived a bone marrow transplant between January 1980 and July 1992. Pa tients who received mechanical ventilation for less than 24 hours afte r a procedure or who received mechanical ventilation after a second bo ne marrow transplantation were excluded. Measurements: Surviving patie nts were defined as those who were alive 30 days after extubation and who were discharged from the hospital. Daily laboratory, physiologic, and treatment variables were collected. Results: Survival was statisti cally associated with younger age, lower score on the Acute Physiology and Chronic Health Evaluation III, and a shorter time from transplant ation to intubation. There were no survivors among an estimated 398 pa tients who had lung injury and either required more than 4 hours of va sopressor support or had sustained hepatic and renal failure. Through the use of these factors, an accurate prediction of death could have b een made in the first 4 days of mechanical ventilation for more than h alf of the patients who did not survive. During the past 5 years, surv ival rate has changed from 5% to 16% (P = 0.008), an increase that was not explained by changes in the age of the patients, the rate or timi ng of intubation, or the percentage of allogeneic transplants that wer e not HLA-identical. Conclusion: Of the patients who required mechanic al ventilation after bone marrow transplantation, no one survived with lung injury combined with either hemodynamic instability or hepatic a nd renal failure. However, survival after mechanical ventilation seems to be improving.