Critical Care Unit Admission Of Hematopoietic Stem Cell Transplant Patients In An University Hospital In Chile

Background: Hematopoietic Stem Cell Transplantation (HSCT) is a potentially curative treatment for a number of hematological malignancies and hereditary disorders. However, patients undergoing HSCT may have serious complications that require support in an intensive care unit (ICU), with significant associated mortality and reported 6-month overall survival (OS) less than 5%.

Patients and methods: Retrospective study of adult patients undergoing autologous, allogeneic and umbilical cord blood HSCT between 2007 and 2011 who required ICU transfer at some point after the HSCT due to severe complicacions of the transplant, at the Catholic University Health Network, Chile, followed 1 year after transplantation.

Results: We analyzed 97 patients, average 37 years old (range: 15-68 years). Main indications for HSCT were hematologic malignancies (84%, n=82), mainly acute lymphoblastic leukemia (29%, n=28), acute myeloid leukemia (21%, n=20), non-Hodgkin lymphoma (13%, n=13) and multiple myeloma (13%, n=13). Ninety percent of the patients (n=87) received myeloablative conditioning regimens including drugs like cyclophosphamide, carmustine, melphalan, etoposide, busulfan and total body irradiation. Twenty nine percent of the patients (n=28/97) were admitted in the ICU (autologous HSCT: 15% [n: 5/33]; allogeneic HSCT: 32% [n=13/41]; cord blood HSCT: 43% [n=10/23]) with an average stay of 19 days (range: 1-73 days) (autologous: 13 days, allogeneic: 16 days, cord blood: 22 days). The median time from admission to transplant to ICU transfer occurred at day 15 after transplantation (autologous: day 3, allogeneic: day 16, cord blood: day 22). Main causes for admission were acute respiratory failure (63%), septic shock (19%) and neurological complications (19%), with similar distribution between the different types of transplants. Among the patients admitted to ICU, 20% (n=1/5) of autologous, 69% (n=9/13) of allogeneic and 70% (n=7/10) of the cord blood HSCT died in the unit. Patients died in the ICU 108 days average after transplantation (range: 4-320) (autologous: 10 days, allogeneic: 131 days, cord blood: 119 days). One-year OS of patients who survived the ICU vs patients never admitted to the ICU was 53% and 85%, respectively (p=0.0036). For allogeneic HSCT, 1-year OS was 15% vs 85% (p<0.0001), for cord blood transplantation 1-year OS was 20% vs 84% (P=0.0008) and for autologous HSCT 1-year OS was 80% vs 89% (pNS), after comparing patients who survived the ICU vs patients never admitted to the ICU, respectively.

Conclusions: Although mortality of HSCT recipients admitted in ICU is high, our results show that intensive support can be beneficial in about half of patients who were admitted, with short to medium outcomes not so unfavorable than has been previously reported.