Characteristics and Outcomes of Patients with Hematological Malignancies Admitted for Intensive Care - a Single Centre Experience

Abstract

Background and Purpose: Patients with hematological malignancies admitted to an intensive care unit (ICU) generally have a high mortality rate. The aim of our study was to assess the characteristics and outcomes of such patients and to identify factors predicting ICU mortality. Material and Methods: This retrospective chart review was conducted in the intensive care unit (ICU) of Shaukat Khanum Memorial Cancer Hospital and Research Centre over a period of 5 years, from January 2010 to January 2015. Results: Characteristics :A total of 213 patients were included in this study. There were 150 (70.4%) males and 63 (29.6%) females with the median age of 36 years (18-88 years). Main diagnosis was non- Hodgkin lymphoma in 127 (59.6%) followed by Hodgkin’s disease in 27 (12.7%) and acute myeloid leukemia in 16 (7.5%). Most of the patients 154 (72.3%) were on active chemotherapy at the time of admission to ICU, while 28 patients (13.1%) had newly diagnosed disease and 22 (10.3%) featured either relapsed or progressive disease. The most common reason for admission to ICU was a combination of respiratory failure with septic shock (29.6%) followed by septic shock alone (19.7%) and acute respiratory failure (13.1%). Other causes included acute renal failure, alone (7.5%) or in combination with respiratory or circulatory collapse (10.8%) and central nervous system involvement (5.6%). The majority of admissions to ICU occurred between days one and five of admission to a ward (46.5%, n=99) whereas 49 (23%) were taken directly to the ICU. Mainstay of treatment in 38.5% of patients included both invasive ventilation and vasopressor support along with other supportive care like fluids and antibiotics. 23.5% received only supportive management. Duration of stay for 150 (70.4%) patients was between one to seven days. Outcomes: A total of 119 (55.9 %) patients expired while in ICU, while 14 (6.6%) died in hospital after being transferred out of ICU. ICU survival was 44.1% whereas hospital survival was 37.5%. After discharge from hospital in a stable condition, 18 (8.5%) patients were lost to follow up and 62 (29%) patients were alive after thirty days. A total of 33 (15.4 %) of patients survived for at least one year after ICU admission. Some 21 (9.8%) are still alive and healthy after a minimum median follow up of one and a half years. Predictors of Mortality: Overall, mechanical ventilation was required in 61% of patients. Out of the patients who expired, 92.4% required intubation, in contrast to 21.3% for those who survived the ICU stay. Involvement of three or more organs was apparent in 12.8% of improved patients and 70.6% of those who died during ICU stay. Neutropenia did not appear to be a major discriminatory factor, with 33% of improved and 42.9% of expired patients being neutropenic at the time of admission to ICU. The majority of patients from both the improved and expired group required intubation and vasopressors from day one onwards. Conclusions: Admission of patients with hematological malignancies to the intensive care unit is associated with poor outcome and high mortality. Identifying the patients who can benefit from aggressive care and prolonged ICU support is important especially when it comes to countries like ours with limited resources and major financial restraints. Multi-organ damage and requirement of invasive ventilation are two main predictors of increased mortality. Neutropenia is also associated with adverse outcome; however, the difference is not as significant as for the other two factors.

Keywords: Intensive care unit; hematological malignancy; mortality; multi-organ dysfunction.