Risk factors and outcome of changes in adrenal response to ACTH in the course of critical illness.

BACKGROUND: To evaluate the concept of critical illness-related corticosteroid insufficiency (CIRCI) by studying the clinical significance, in terms of risk factors and outcome, of changes in the cortisol response to repeated adrenocorticotropic hormone (ACTH) testing in the course of critical illness. PATIENTS AND METHODS: In a retrospective study in a medical-surgical intensive care unit (ICU) of a university hospital, we retrospectively included 54 consecutive patients during a 3-year period, who underwent 2 conventional 250 µg ACTH tests at an interval >24 hours, because of ≥6 hours hypotension requiring repeated fluid challenges or vasopressor/inotropic treatment, while corticosteroid treatment was not (yet) initiated. Serum cortisol was measured immediately before and 30 and 60 minutes after intravenous injection of 250 µg of ACTH. Patients were divided into those with an increase (≥0, n = 27) or a decrease (n = 27) in time in delta (Δ) cortisol in response to ACTH and with a Δcortisol <100 (n = 11) and ≥100 nmol/L (n = 43) at the second ACTH test. RESULTS: Changes in Δcortisol in time were paralleled by changes in Δcortisol/albumin, with a higher frequency of septic shock, persistently high disease severity, increased renal replacement therapy, and decreased platelet counts in the course of disease with a decrease in Δcortisol in time. Similar trends in increased disease severity were observed when Δcortisol remained or fell to <100 nmol/L. A decrease in Δcortisol between the 2 tests, particularly to <100 nmol/L, was associated with increased mortality (18 nonsurvivors in the ICU). CONCLUSIONS: The findings favor the concept of dynamic adrenal function rather than poor reproducibility of the ACTH test, so that development of CIRCI, particularly in complicated septic shock and indicated by a fall in Δcortisol (to <100 nmol/L) upon ACTH, correlates to a poor prognosis, independently of baseline cortisol, cortisol binding in blood, and disease severity.

Should we abandon corticosteroids during septic shock? No.

PURPOSE OF REVIEW: With the publication of the results of the recent CORTICUS trial, stress ('low') doses of corticosteroids for the treatment of vasopressor-dependent septic shock in adults can still be considered controversial. The purpose of this narrative review is to elaborate the pros and cons of this treatment in clinical practice and to formulate clinical and research directions. RECENT FINDINGS: The recent CORTICUS study only shows a beneficial effect of stress doses of corticosteroids in the time interval to shock reversal and not on mortality, potentially explained by an increased risk for superinfection. The mortality in the placebo arm was relatively low and lower than in earlier randomized studies in which stress doses of corticosteroids had a favorable hemodynamic effect and conferred a survival benefit in septic shock. SUMMARY: Treatment by stress doses of corticosteroids should not be abandoned during septic shock. Additional studies are needed, however, to better delineate the patient group with the highest likelihood to benefit from this therapy, as a function of severity of illness, response to adrenocorticotrophic hormone testing or both. For now, results of the CORTICUS study should not change current clinical practice of administering 200-300 mg of hydrocortisone daily (in divided doses) in case of fluid and vasopressor-insensitive septic shock and rapid tapering of this treatment on the basis of a hemodynamic response.

Correlates of thenar near-infrared spectroscopy-derived tissue O2 saturation after cardiac surgery.

We studied the significance of near-infrared spectroscopy (NIRS), for measuring tissue oxygenation (S(t)O(2)) and perfusion adequacy, and thus for haemodynamic monitoring of patients after cardiac surgery. We compared NIRS-derived S(t)O(2) of the thenar muscle to haemodynamic variables, oxygenation indices, temperature, lactate levels and urinary output, in 23 patients in the course of time after cardiac surgery and admission into the intensive care unit. Clinical variables, global haemodynamics and NIRS% total haemoglobin (%HT) and S(t)O(2) in the thenar for up to 18-22 h after admission were measured. The S(t)O(2) declined concomitantly with a rise in the body-finger temperature difference. Cardiac output did not change but mean arterial pressure rose, concomitantly with tapering doses of nitroglycerine, indicative of an increase in vascular tone during recovery from surgery. From all variables, changes in body-finger temperature difference best correlated to changes in S(t)O(2) (r(s)=-0.48, P<0.001). As judged from clinical and haemodynamic correlates, thenar NIRS S(t)O(2) is a non-invasive measure of peripheral rather than global perfusion adequacy, after cardiac surgery. This may help to define the role of thenar NIRS monitoring after cardiac surgery in future studies.