Sequential organ failure assessment in neurocritical care

Purpose

To determine the incidence of non-neurological organ dysfunction in the neurologically injured patient and to determine its association with outcome.

Methods

We calculated daily modified SOFA (mSOFA) scores for patients with TBI or SAH admitted to the Neuroscience Critical Care Unit at Addenbrooke's Hospital. The mSOFA score was defined as the sum of the five non-neurological component SOFA scores (range 0–20). Maximum mSOFA was defined as the sum of the most abnormal non-neurological SOFA component scores during the patient's stay. ΔmSOFA was defined as the difference between the maximum SOFA and the admission mSOFA. An organ system failure was defined as a SOFA component score ≥ 3.

Results

Thirty-two patients with severe TBI and 23 patients with SAH were included in the study. Sixty-seven per cent of patients were male. Mean age was 41 ± 18. The mean APACHE II score was 13.6 ± 6.8. Hospital mortality was 29%. Median ICU LOS was 11 days. Mean admission, maximum and ΔmSOFA scores were 4.4 ± 2.5, 7.2 ± 2.7, and 2.8 ± 2.1, respectively. Eighty per cent of patients developed respiratory failure and 82% of patients developed cardiovascular failure. No patient developed renal or hepatic failure. Three patients (5.5%) developed haematological failure. Those patients with a maximum mSOFA score ≥ 8 had significantly longer ICU and hospital LOS. There was no significant difference between survivors and nonsurvivors with respect to admission mSOFA (P = 0.45), maximum mSOFA (P = 0.54), or ΔmSOFA (P = 0.19). Neurological outcome was available for 45 patients (82%). There was no significant difference between those patients with good or poor neurological outcome with respect to admission mSOFA (P = 0.24), maximum mSOFA (P = 0.84), or ΔmSOFA (P = 0.20). The development of multiple organ dysfunction (≥ 2 organ dysfunctions) was not associated with mortality or neurological outcome.

Conclusions

We found no association between non-neurological organ dysfunction as measured by the modified SOFA score and mortality or neurological outcome. The use of sequential organ dysfunction scores as surrogate outcomes in this population must be questioned.