A Study of Factors Influencing Outcome In Patients with Haematological Malignancy Requiring High Dependency Support In a Large UK Haematology and Bone Marrow Transplant Centre
Authors: Choudhuri Satarupa , Somervaille Tim , Michael Phil Haji , Dennis Mike 
Published: October 2019

Abstract
Abstract 4732

Introduction:
Controversy surrounds the decision to admit a patient with Haematological malignancy to receive treatment in a Level 2- High Dependency Unit with patients needing single organ support or Level 3 – intensive care with patents requiring two or more organ support setting. Little is known regarding factors influencing outcome of such patients when admitted to such a setting.

Methodology:
We performed a retrospective case note review supplemented by computer database analysis of all patients admitted to the High Dependency Unit (HDU) at Christie Hospital, Manchester between October 2008 and January 2010.

Results:
53 episodes in 53 patients (Median age 60 (IQR 44–66) years; 36 (68%) male) with known haematological malignancy were studied. The underlying diagnoses included AML (40%), NHL/HCL (13%), CLL (11%), Multiple Myeloma (11%), ALL (9%) and CML (6%). 51% (27/53) had undergone Stem Cell Transplantation; 15% (8/53) Allogeneic from a Matched Unrelated Donor, 23% (12/53) Sibling and 13% (7/53) Autologous. Of the 20 Allogeneic transplants, 7 (35%) had Full Intensity and 11 (55%) had Reduced Intensity conditioning. 25% had Graft versus Host disease (GVHD) at the time of HDU admission.
The trigger leading to HDU admission was septic shock (46%), bacterial pneumonia (24%), cardiac decompensation (10%) and other causes in 20% (viral pneumonia, infective colitis and neurological). Admission APACHE score in the overall cohort was 21 (IQR 17–25); 32% (17/53) required CPAP whilst 40% received inotropic support. Pre admission observations noted to be associated with subsequent increased mortality were tachycardia (heart rate>100), tachypnoea (respiratory rate > 20 per minute), systolic hypotension (SBP < 70mm Hg), acidaemia (pH < 7.4) and septic shock requiring ionotropic support. Of note is that neutropenia (absolute neutrophil count <1) at the time of HDU admission did not seem to affect outcome.
In-hospital HDU mortality in the overall sample was 13% (7 of 53 patients) with median length of stay being 4 (IQR 2–7) days. 38% (20/53) were alive at 1 month and 31% (16/53) were still alive by 6 months post HDU discharge. 28% (15/53) were transferred from HDU for Level 3 support and all these patients were intubated and mechanically ventilated. Of these transfers, 40% (6/15) survived to discharge.
Patients receiving Allogeneic Sibling donor transplants exhibited improved 1 and 6 month survival when compared to Allogeneic Matched Unrelated Donor transplant recepient (p=0.011) although no statistically significant difference in short and long term survival or in length of stay on HDU were noted between those who had received Full Intensity Conditioning compared to Reduced Intensity Conditioning. Using Kaplan-Meier Survival analysis, median survival in those with an underlying diagnosis of MDS/AML was 11 months compared to 3 months in NHL and CLL.

Conclusion:
Patients with Haematological conditions do not necessarily exhibit a uniformly poor outcome when admitted for Level 2 (High Dependency) care with 87% surviving the episode. This is further emphasized by the fact that 40% patients requiring intubation and invasive mechanical ventilation survived to discharge. Matched unrelated donor transplants fared worse compared to Sibling and Autologous transplant cases. Interestingly, patients receiving Full and Reduced Intensity conditioning regimes showed no difference in admission mortality and length of stay.

Disclosures:
No relevant conflicts of interest to declare.