HYPOCORTISOLAEMIA AND ADRENOCORTICAL RESPONSIVENESS AT ONSET OF SEPTIC SHOCK

Objective: To characterise the plasma cortisol profile and adreno-cort ial responsiveness (short Synacthen test) of patients in septic shock. Design: Retrospective assessment using case-notes and ICU charts. Set ting: University teaching hospital ICU. Patients: 68 septic shock pati ents with plasma cortisol and/or short Synacthen test measured at ICU- admission or onset of shock post ICU-admission. Patients were identifi ed from a total population of 155 patients who had PCL and/or SST meas ured over a 4.5 year period. Intervention: None Measurements and resul ts: Patients with septic shock had a plasma cortisol ranging from 210- 8900 nmol/l and mortality of 56%. There were 22 (32%) below (low) and 46 (68%) above (high) a 'critical' plasma cortisol of 500 nmol/l. Usin g stepwise logistic regression, mortality was adequately predicted by and increased with, increasing plasma cortisol and onset of shock remo te from ICU-admission. Short Synacthen tests were available in 33 pati ents: 11 responders (cortisol increment > 200 nmol/l above baseline 30 min after 0.25 mg intravenous Synacthen) and 22 hypo-responders. Mort ality in patients was adequately predicted by and increased with a dec rease in cortisol increment post-Synacthen. Thirteen patients (plasma cortisol 606 +/-[SD] 297nmol/l) had complete haemodynamic profiles bef ore inotropic therapy; no relationship was demonstrated between plasma cortisol and circulatory variables. Follow-up revealed no cases of Ad dison's disease. Conclusions: In septic shock, 'hypocortisolaemia' is not uncommon and does not predict a high mortality; adrenocortical hyp o-responsiveness may be associated with poor outcome.