Sequential organ failure predicts mortality of patients with a haematological

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Blackwell Munksgaard 2005

Eur J Haematol 2005: 74: 511–516 All rights reserved

EUROPEAN JOURNAL OF HAEMATOLOGY

Sequential organ failure predicts mortality of patients with a haematological malignancy needing intensive care Cornet AD, Issa AI, van de Loosdrecht AA, Ossenkoppele GJ, Strack van Schijndel RJM, Groeneveld ABJ. Sequential organ failure predicts mortality of patients with a haematological malignancy needing intensive care. Eur J Haematol 2005: 74: 511–516.
Blackwell Munksgaard 2005.

Alexander D. Cornet1, Aart I. Issa1, Arjan A. van de Loosdrecht2, Gert J. Ossenkoppele2, Rob J. M. Strack van Schijndel1, A. B. Johan Groeneveld1 1

Abstract: Objectives: Poor survival of patients with a haematological malignancy admitted to the intensive care unit (ICU) prompts for proper admission triage and prediction of ICU treatment failure and long-term mortality. We therefore tried to find predictors of the latter outcomes. Methods: A retrospective analysis of charts and a prospective follow-up study were done, of haemato-oncological patients, admitted to our ICU in a 7-year period with a follow-up until 2 yr thereafter. Clinical parameters during the first four consecutive days were taken to calculate the simplified acute physiology (SAPS II) and the sequential organ failure assessment (SOFA) scores, of proven predictive value in general ICU populations. Results: From a total of 58 patients (n ¼ 47 with acute myelogenous leukaemia or non-Hodgkin lymphoma), admitted into ICU mostly because of respiratory insufficiency, sepsis, shock or combinations, 36 patients had died during their stay in the ICU. Of ICU survivors (n ¼ 22), 20 patients died during follow-up so that the 1-year survival rate was only 12%. The SAPS II and particularly the SOFA scores were of high predictive value for ICU and long-term mortality. Conclusions: Patients with life-threatening complications of haematological malignancy admitted to ICU ran a high risk for death in the ICU and on the long-term, and the risk can be well predicted by SOFA. The latter may help us to decide on intensive care in individual cases, in order to avoid potentially futile care for patients with a SOFA score of 15 or higher.

Patients admitted into the intensive care unit (ICU) because of complications in the treatment of a haematological malignancy often have a poor prognosis, with an ICU or hospital mortality rate of 50–95%. The outcome varies widely among studies, however, partly due to differences in casemix, with extremely poor outcomes, for instance, reported for bone marrow/stem cell recipients (1–12). Moreover, the prognosis of haemato-oncological patients on the ICU might have improved over the past decades, at least on the short term (9, 11, 12). Data on long-term mortality (up to 1 yr) are scarce, however, so that it cannot be fully assessed if the efforts in the ICU are still ÔworthwileÕ (3, 7, 8, 13). Indeed, long-term survival may depend

Department of Intensive Care, Institute for Cardiovascular Research, Vrije Universiteit Medical Centre, Amsterdam, the Netherlands; 2Department of Haematology, Vrije Universiteit Medical Centre, Amsterdam, the Netherlands

Key words: haematological malignancy; ICU (Intensive Care Unit); SOFA-score; SAPS II; long-term survival Correspondence: Prof. Dr Johan Groeneveld MD PhD FCCP FCCM, Intensive Care, Vumc, De Boelelaan 1117 1081 HV, Amsterdam, the Netherlands Tel.: +31-20-4444178 Fax: +31-20-4442392 e-mail: [email protected] Accepted for publication 19 December 2004

on the prognosis of the underlying disease rather than on superimposed vital organ dysfunction necessitating intensive care, while the latter may be of greater importance in predicting short-term mortality (6–8, 11, 13). Prediction of intensive care treatment failure or success and long-term outcome is important to help decision-making concerning ICU admission once a life-threatening complication of haematological malignancy has developed. In the past, several scoring methods have been developed to predict whether or not general ICU patients will survive. Even though some of these systems take the presence of haematological malignancy into account, it is unclear if the Acute Physiology and 511

Cornet et al. Chronic Health Evaluation (APACHE II/III) score (2, 5, 6, 8–10, 12), the Simplified Acute Physiology Score (SAPS II) (3, 7, 8, 10, 14) and the Sequential Organ Failure Assessment (SOFA) (11) are of major value in predicting ICU survival from such malignancies. Surprisingly, no or only minimal predictive values in haemato-oncologic patients have been reported (4–8, 10, 12, 14). The current study was undertaken to evaluate the ICU and long-term (i.e. 1 and 3 yr) outcome and its potential predictors SAPS II and SOFA, for critically ill patients with a haematological malignancy. Patients and methods

A retrospective study was done on consecutive patients admitted with a known haematological malignancy from the haematological department into the 7-bed medical ICU of our 700-bed university hospital, from 1 November 1995 to 31 December 2002. Follow-up was completed on 1 January 2004, and for only one, ultimately dying patient the survival time remained unknown. Predefined lists were completed of data collected, in a standardized manner, from patient charts. Demographics, underlying haematological malignancy, reason of admission to the ICU, and comorbidity were taken from the charts. Patients had been monitored by repeated laboratory determinations, at least once daily, and, when necessary, by invasive haemodynamic and ventilatory monitoring, and data had been recorded in an electronic patient data management system in use in our ICU. Data were extracted from the electronic and written patient charts in order to calculate, using the worst value in a 24 h time frame for each variable, and for the day of admission (Day 0) as well as the three following days (Days 1–3), the Simplified Acute Physiology Score (SAPS II, 0–160) (15), that takes the presence of a haematological malignancy into

account, and the Sequental Organ Failure Assessment (SOFA, 0–24) score (Table 1, Ref. 16). The former score takes age, type of admission, presence of chronic disease and 12 organ-specific clinical and laboratory variables into account and the latter consists of a score of six organ-specific clinical and laboratory variables. The presedation score on the Glasgow coma scale was used. While SAPS II is typically an admission score, the daily SOFA has been developed to characterize disease course in time. Daily chest radiographs were scored from 1 to 4 for the number of quadrants with alveolar consolidations and together with ventilatory and gas exchange parameters, the Lung Injury Score (LIS, 17) was calculated. The score ranges between 0 and 4 and a value >2.5 have been regarded to indicate acute respiratory distress syndrome (ARDS). For scoring systems, missing values were classified as normal. Likely clinical infection sources were noted, as well as microbiological results, including those obtained from bronchoalveolar lavage (BAL) fluid, within a window of 7 d around the day of admission. The use and duration of inotropic support, mechanical ventilation and continuous renal replacement techniques were recorded. Statistical analyses

Outcome groups defined on the basis of mortality/ survival in the ICU were compared with help of an unpaired Mann–Whitney U-test or, for categorical variables with the Fisher’s exact and v2-tests. The log rank test was used to compare long-term mortality in SOFA strata, after constructing Kaplan–Meier survival plots. Receiver operating characteristic (ROC) curves were constructed, plotting sensitivity vs. 1-specificity to evaluate the predictive value of variables for ICU outcome and the more an area under the curve (AUC with 95% confidence intervals, CI) approaches 1, the

Table 1. The sequential organ failure assessment (SOFA) score SOFA 0

1 £400

2 £300

3 £200

4

PaO2/FiO2

>400

Platelets (·109/L) Bilirubin (lM/L) No Hypotension Glasgow coma score Scale Creatinine (lMol/L) Urinary output (mL/d)

>150 204 Dob >15, Epi >0.1 or Nor >0.1

15 >170

13–14 110–170

10–12 171–299

6–9 300–440