Intensive Care Unit Admissions in Patients with Hematologic Malignancies: Outcomes and Prognostic Indicators.

With intensification in treatments of hematologic malignancies (HM), the number of life-threatening complications requiring intensive care unit (ICU) admissions has increased. In general, cancer patients requiring ICU care are considered to have a poor prognosis, but it is a common belief among intensivists that patients with HM have an exceptionally grave prognosis. The aim of the current study was to assess outcomes in patients with HM admitted to the ICU for life-threatening complications. In addition, this study intended to identify early prognostic indicators that would be helpful in determining outcomes of ICU stay in this patient population. We performed a retrospective chart review of 185 consecutive critically ill patients with HM admitted to the ICU at a tertiary university hospital during a 5.5-year period. We collected variables ar admission and during admission and identified predictors of in-hospital mortality by Cox proportional hazard analysis. 88.7% patients had active disease, and 36.2% were bone marrow transplant (BMT) recipients. 24.3% were leukopenic (leukocyte count,<1.0x10⁹/L) at admission. Sepsis (30.3%), respiratory failure (17.3%), and post-surgical complications (16.2%) were the major reasons for ICU admissions. 22.2% required vasopressors at admission. 38.4% required mechanical ventilation (MV) and 9.2% needed hemodialysis during ICU stay. Crude ICU, in-hospital, and 6-month mortality rates were 19.5%, 8.1%, and 9.7%, respectively. MV (hazard ratio, 2.75), blood urea nitrogen (BUN)>22 (hazard ratio, 1.81), pre-existent COPD/Asthma (hazard ratio, 3.24), urine output (UOP)<400 ml/24hr (hazard ratio, 2.8) were associated with poor outcome, while high albumin (hazard ratio, 0.54) was associated with better prognosis in multivariate Cox proportional hazard analysis. Using an univariate logistic regression model, diagnosis of acute leukemia (odds ratio, 2.42; 95% confidential interval, 1.23–4.75) or allogeneic BMT (odd ratio, 4.33; 95% confidence interval, 1.17–16.06) were associated with poor outcome, whereas diagnosis of lymphoma (odd ratio, 0.34; 95% confidence interval, 0.16–0.72) or APACHE II<22 (odd ratio, 0.33; 95% confidence interval, 0.17–0.65) were associated with better prognosis. Using these variables, we categorized our population into 4 groups: a very low risk group (lymphoma or other non-leukemia in combination with no need for MV and good UOP/normal BUN), a low risk group (lymphoma or other non-leukemia in combination with either MV, or low UOP/high BUN, or both), an intermediate risk group (leukemia or post-BMT in combination with either MV, or low UOP/high BUN, or neither negative factors), and a high risk group (leukemia or post-BMT in combination with MV and low UOP/high BUN). Survival probabilities at 6 months were 85%, 50%, 47%, and 16%, respectively (p<0.0001). The survival of patients with HM in the ICU was compatible with overall ICU survival at our institution, contrary to prevailing opinion. However, we identified several early predictors of outcome that may be important in deciding on prolonged ICU stay.