Improved Survival in Cancer Patients Requiring Mechanical Ventilatory Support: Impact of Noninvasive Mechanical Ventilatory Support

Objective: When a cancer patient becomes critically ill, mechanical ventilation (MV) is often considered futile. However, recent studies have found that outcomes of critically ill cancer patients have been improving over the years and that classic predictors of high mortality have lost their relevance.

Design: We retrospectively determined outcomes and predictors of 30-day mortality in 237 mechanically-ventilated cancer patients admitted to the intensive care unit (ICU).

Patients: The 132 (55.7%) patients who were admitted between 1990 and 1995 were compared with 105 (44.3%) patients who were admitted between 1996 and 1998. The malignancy was leukemia/lymphoma in 119 (50.3%) patients, myeloma in 50 (21%), and a solid tumor in 68 (28.7%). Forty-two (17.7%) patients had bone marrow transplantation, and 91 (38.4%) were neutropenic. Median Simplified Acute Physiology Score II (SAPS II) was 58 (range, 40-75). Reasons for MV were acute hypoxemic respiratory failure in 148 (62.5%) patients, coma in 54 (22.8%), and cardiogenic pulmonary edema in 35 (14.7%). Conventional MV was used first in 189 (79.8%) patients, and noninvasive MV (NIMV) was used in 48 (20.2%). Overall mortality rate was 72.5% (172 deaths).

Results: Logistic regression identified three variables associated with mortality: ICU admission between 1996 and 1998 (odds ratio [OR], 0.24; 95% confidence interval [CI], 0.12-0.50) and the use of NIMV (OR, 0.34; 95% CI, 0.16-0.73) were protective, and the SAPS II was aggravating (OR, 1.04 per point; 95% CI, 1.02-1.06). To better define the impact of NIMV, we performed a pairwise-matched exposed-unexposed analysis. Forty-eight patients who did and 48 who did not receive NIMV as the first ventilation method were matched for SAPS II, type of malignancy, and period of ICU admission. Crude ICU mortality rates from exposed patients and controls were 43.7% and 70.8%, respectively. NIMV remained protective from mortality after adjustment for matching variables (OR, 0.31; 95% CI, 0.12-0.82).

Conclusion: Our results confirm that mortality has improved over the past decade in critically ill cancer patients, even those who require MV, and suggest that this may be, in part, because of a protective effect of NIMV.