Comparison of low and high dose cosyntropin stimulation tests in the diagnosis of adrenal insufficiency in septic shock patients.

Stress situations such as septic shock are accompanied by activation of the HPA axis. Some patients do not activate this axis in stress situations. This blunted response is currently designated as critical illness-related corticosteroid insufficiency (CIRCI). Currently the 250 µg cosyntropin stimulation test is the preferred diagnostic test for CIRCI. Few papers explored the role of the 1 µg cosyntropin test in septic shock patients. In this study, we compared both tests in septic shock patients taking a special interest in the population with intermediary baseline cortisol. Prospective noninterventional study included 74 septic shock patients. After measurement of baseline cortisol all patients received 1 µg of cosyntropin i. v. and 4 h later 249 µg of cosyntropin. We compared the cortisol increase after each test and its relation to mortality and vasopressor therapy. There was a moderate correlation in response to low and high dose cosyntropin, r(s)=0.55. This correlation in patients with baseline cortisol between 10-34 µg/dl is, r(s)=0.67. The increase induced by both tests was equally accurate to identify mortality and time of vasopressor withdrawal. Low and high dose cosyntropin tests presented a moderate correlation in patients with baseline cortisol between 10-34 µg/dl. Both tests are equally accurate to identify mortality and time of vasopressor therapy. These results suggest that both tests could be used to diagnose CIRCI.

Noradrenaline use is not associated with extubation failure in septic patients.

Standard clinical practice recommends minimal doses of vasoactive drugs during weaning of patients from mechanical ventilation. However there are currently no clinical data to inform clinicians about whether the use of noradrenaline during weaning predisposes to weaning failure. The objective of this study was to evaluate whether the necessity of the vasopressor noradrenaline in mechanically ventilated patients recovering from septic shock changed the extubation outcome. A total of 656 patients recovering from septic shock on mechanical ventilation were selected from intensive care units in two university hospitals. Patients receiving noradrenaline at the time of weaning and case-controls not taking noradrenaline were matched for age, gender, haemodynamic and ventilatory parameters, aetiology of respiratory failure and APACHE II score. One hundred and forty-five patients who successfully tolerated a spontaneous breathing trial were extubated while on noradrenaline therapy and the reintubation rate was measured. In the noradrenaline group, the mean dose of noradrenaline during initial shock treatment was 0.52+/-0.29 microg/kg/min and 0.12+/-0.10 microg/kg/min during weaning. The reintubation rate was 12/63 (19%) in the noradrenaline group and 15/82 (18.3%) in the control group (P=1.00). Intensive care unit mortality was also similar in both groups (10/63, 15.9%) for noradrenaline patients and (11/82, 13.4%) for control patients (P=0.81). Arterial blood gases and ventilatory and haemodynamic parameters were similar in all patients regardless of weaning success. We did not find that the use of noradrenaline at the time of weaning was associated with extubation failure. Low doses of noradrenaline may not preclude weaning from mechanical ventilation.