Critical illness in systemic lupus erythematosus and the antiphospholipid syndrome

To investigate the causes, course, and outcome of critical illness requiring emergency admission to the intensive care unit (ICU) in patients with systemic lupus erythematosus (SLE) or the antiphospholipid syndrome (APS), or both.

Critically ill patients with SLE or APS, or both, admitted to a London teaching hospital ICU over a 15 year period were studied. Demographic, diagnostic, physiological, laboratory, and survival data were analysed. Kaplan-Meier survival curves were constructed by age, time from first diagnosis of SLE, and time from first ICU admission. The log rank test and a backwards stepwise Cox regression were used to identify factors associated with reduced survival.

Sixty one patients with SLE alone (39%) and/or APS (61%) required 76 emergency admissions to the ICU. Patients had high severity of illness scores (median APACHE II 22 (range 8-45)) and multiorgan dysfunction. The primary diagnoses for patients admitted were infection in 31/76 (41%), renal disease in 16/76 (21%), cardiovascular disease in 12/76 (16%), and coagulopathies in 11/76 (14%). The commonest secondary diagnosis was renal dysfunction (49%). Factors associated with an increased risk of death were cyclophosphamide before admission, low white cell count, and high severity of illness score. Before adjustment for these factors renal disease had a strong adverse effect on long term survival (analysis by age at diagnosis p=0.005, analysis by time since first ICU admission, p=0.07). After adjustment, infection at admission to ICU was associated with an increased ICU mortality (p=0.02) and was the cause of death in 13/17 patients who died in the ICU. Similarly, after adjustment, APS was associated with reduced ICU survival (p=0.1) and reduced long term (p=0.03) survival. Seventeen patients (28%) died in the ICU, and 31 patients (51%) had died by the last follow up. Median time from ICU admission to death was four years. Overall five year survival from the first ICU admission was 43%.

Critical illness requiring ICU admission may occur in patients with SLE and APS. In this study, ICU survival was better than previously described, but long term survival was poor. Cyclophosphamide administration, low white cell count, and high severity of illness score were associated with reduced survival. Before adjustment for these factors, only renal disease had an adverse effect on outcome but after adjustment, infection and APS reduced survival.