The effect of higher or lower mean arterial pressure on kidney function after cardiac arrest: a post hoc analysis of the COMACARE and NEUROPROTECT trials.

BACKGROUND: We aimed to study the incidence of acute kidney injury (AKI) in out-of-hospital cardiac arrest (OHCA) patients treated according to low-normal or high-normal mean arterial pressure (MAP) targets. METHODS: A post hoc analysis of the COMACARE (NCT02698917) and Neuroprotect (NCT02541591) trials that randomized patients to lower or higher targets for the first 36 h of intensive care. Kidney function was defined using the Kidney Disease Improving Global Outcome (KDIGO) classification. We used Cox regression analysis to identify factors associated with AKI after OHCA. RESULTS: A total of 227 patients were included: 115 in the high-normal MAP group and 112 in the low-normal MAP group. Eighty-six (38%) patients developed AKI during the first five days; 40 in the high-normal MAP group and 46 in the low-normal MAP group (p = 0.51). The median creatinine and daily urine output were 85 µmol/l and 1730 mL/day in the high-normal MAP group and 87 µmol/l and 1560 mL/day in the low-normal MAP group. In a Cox regression model, independent AKI predictors were no bystander cardiopulmonary resuscitation (p < 0.01), non-shockable rhythm (p < 0.01), chronic hypertension (p = 0.03), and time to the return of spontaneous circulation (p < 0.01), whereas MAP target was not an independent predictor (p = 0.29). CONCLUSION: Any AKI occurred in four out of ten OHCA patients. We found no difference in the incidence of AKI between the patients treated with lower and those treated with higher MAP after CA. Higher age, non-shockable initial rhythm, and longer time to ROSC were associated with shorter time to AKI. CLINICAL TRIAL REGISTRATION: COMACARE (NCT02698917), NEUROPROTECT (NCT02541591).

Association of deranged cerebrovascular reactivity with brain injury following cardiac arrest: a post-hoc analysis of the COMACARE trial.

BACKGROUND: Impaired cerebrovascular reactivity (CVR) is one feature of post cardiac arrest encephalopathy. We studied the incidence and features of CVR by near infrared spectroscopy (NIRS) and associations with outcome and biomarkers of brain injury. METHODS: A post-hoc analysis of 120 comatose OHCA patients continuously monitored with NIRS and randomised to low- or high-normal oxygen, carbon dioxide and mean arterial blood pressure (MAP) targets for 48 h. The tissue oximetry index (TOx) generated by the moving correlation coefficient between cerebral tissue oxygenation measured by NIRS and MAP was used as a dynamic index of CVR with TOx > 0 indicating impaired reactivity and TOx > 0.3 used to delineate the lower and upper MAP bounds for disrupted CVR. TOx was analysed in the 0-12, 12-24, 24-48 h time-periods and integrated over 0-48 h. The primary outcome was the association between TOx and six-month functional outcome dichotomised by the cerebral performance category (CPC1-2 good vs. 3-5 poor). Secondary outcomes included associations with MAP bounds for CVR and biomarkers of brain injury. RESULTS: In 108 patients with sufficient data to calculate TOx, 76 patients (70%) had impaired CVR and among these, chronic hypertension was more common (58% vs. 31%, p = 0.002). Integrated TOx for 0-48 h was higher in patients with poor outcome than in patients with good outcome (0.89 95% CI [- 1.17 to 2.94] vs. - 2.71 95% CI [- 4.16 to - 1.26], p = 0.05). Patients with poor outcomes had a decreased upper MAP bound of CVR over time (p = 0.001), including the high-normal oxygen (p = 0.002), carbon dioxide (p = 0.012) and MAP (p = 0.001) groups. The MAP range of maintained CVR was narrower in all time intervals and intervention groups (p < 0.05). NfL concentrations were higher in patients with impaired CVR compared to those with intact CVR (43 IQR [15-650] vs 20 IQR [13-199] pg/ml, p = 0.042). CONCLUSION: Impaired CVR over 48 h was more common in patients with chronic hypertension and associated with poor outcome. Decreased upper MAP bound and a narrower MAP range for maintained CVR were associated with poor outcome and more severe brain injury assessed with NfL. Trial registration ClinicalTrials.gov, NCT02698917 .

Prevalence and impact of hazardous alcohol use in intensive care cohort: A multicenter, register-based study.

BACKGROUND: Reports of the prevalence and impact of hazardous alcohol use among intensive care unit (ICU) patients are contradictory. We aimed to study the prevalence of hazardous alcohol use among ICU patients and its association with ICU length of stay (LOS) and mortality. METHODS: Finnish ICUs have been using the Alcohol Use Disorder Identification Test-Consumption (AUDIT-C) to evaluate and record patients' alcohol use into the Finnish Intensive Care Consortium's Database (FICC). We retrieved data from the FICC from a 3-month period. We excluded data from centers with an AUDIT-C recording rate of less than 70% of admissions. We defined hazardous alcohol use as a score of 5 or more for women and 6 or more for men from a maximum score of 12 points. RESULTS: Two thousand forty-five patients were treated in the 10 centers with an AUDIT-C recording rate of 70% or higher. AUDIT-C was available for 1576 (77%) patients and indicated hazardous alcohol use for 334 (21%) patients who were more often younger (median age 55 [interquartile range 42-65] vs 67 [57-74] [P < .001]) and male (78.1% vs 61.3% [P < .001]) compared to other patients. We found no difference in LOS or hospital mortality between hazardous and non-hazardous alcohol users. Among the non-abstinent, risk of death within a year increased with increasing AUDIT-C scores adjusted odds ratio 1.077 (95% confidence interval, 1.006-1.152) per point. CONCLUSION: The prevalence of hazardous alcohol use in Finnish ICUs was 21%. Patients with hazardous alcohol use were more often younger and male compared with non-hazardous alcohol users.

Serum fibroblast growth factor 21 levels after out of hospital cardiac arrest are associated with neurological outcome.

Fibroblast growth factor (FGF) 21 is a marker associated with mitochondrial and cellular stress. Cardiac arrest causes mitochondrial stress, and we tested if FGF 21 would reflect the severity of hypoxia-reperfusion injury after cardiac arrest. We measured serum concentrations of FGF 21 in 112 patients on ICU admission and 24, 48 and 72 h after out-of-hospital cardiac arrest with shockable initial rhythm included in the COMACARE study (NCT02698917). All patients received targeted temperature management for 24 h. We defined 6-month cerebral performance category 1-2 as good and 3-5 as poor neurological outcome. We used samples from 40 non-critically ill emergency room patients as controls. We assessed group differences with the Mann Whitney U test and temporal differences with linear modeling with restricted maximum likelihood estimation. We used multivariate logistic regression to assess the independent predictive value of FGF 21 concentration for neurologic outcome. The median (inter-quartile range, IQR) FGF 21 concentration was 0.25 (0.094-0.91) ng/ml in controls, 0.79 (0.37-1.6) ng/ml in patients at ICU admission (P < 0.001 compared to controls) and peaked at 48 h [1.2 (0.46-2.5) ng/ml]. We found no association between arterial blood oxygen partial pressure and FGF 21 concentrations. We observed with linear modeling an effect of sample timepoint (F 5.6, P < 0.01), poor neurological outcome (F 6.1, P = 0.01), and their interaction (F 3.0, P = 0.03), on FGF 21 concentration. In multivariate logistic regression analysis, adjusting for relevant clinical covariates, higher average FGF 21 concentration during the first 72 h was independently associated with poor neurological outcome (odds ratio 1.60, 95% confidence interval 1.10-2.32). We conclude that post cardiac arrest patients experience cellular and mitochondrial stress, reflected as a systemic FGF 21 response. This response is higher with a more severe hypoxic injury but it is not exacerbated by hyperoxia.

Neurofilament light as an outcome predictor after cardiac arrest: a post hoc analysis of the COMACARE trial.

PURPOSE: Neurofilament light (NfL) is a biomarker reflecting neurodegeneration and acute neuronal injury, and an increase is found following hypoxic brain damage. We assessed the ability of plasma NfL to predict outcome in comatose patients after out-of-hospital cardiac arrest (OHCA). We also compared plasma NfL concentrations between patients treated with two different targets of arterial carbon dioxide tension (PaCO2), arterial oxygen tension (PaO2), and mean arterial pressure (MAP). METHODS: We measured NfL concentrations in plasma obtained at intensive care unit admission and at 24, 48, and 72 h after OHCA. We assessed neurological outcome at 6 months and defined a good outcome as Cerebral Performance Category (CPC) 1-2 and poor outcome as CPC 3-5. RESULTS: Six-month outcome was good in 73/112 (65%) patients. Forty-eight hours after OHCA, the median NfL concentration was 19 (interquartile range [IQR] 11-31) pg/ml in patients with good outcome and 2343 (587-5829) pg/ml in those with poor outcome, p < 0.001. NfL predicted poor outcome with an area under the receiver operating characteristic curve (AUROC) of 0.98 (95% confidence interval [CI] 0.97-1.00) at 24 h, 0.98 (0.97-1.00) at 48 h, and 0.98 (0.95-1.00) at 72 h. NfL concentrations were lower in the higher MAP (80-100 mmHg) group than in the lower MAP (65-75 mmHg) group at 48 h (median, 23 vs. 43 pg/ml, p = 0.04). PaCO2 and PaO2 targets did not associate with NfL levels. CONCLUSIONS: NfL demonstrated excellent prognostic accuracy after OHCA. Higher MAP was associated with lower NfL concentrations.

Optimum Blood Pressure in Patients With Shock After Acute Myocardial Infarction and Cardiac Arrest.

BACKGROUND: In patients with shock after acute myocardial infarction (AMI), the optimal level of pharmacologic support is unknown. Whereas higher doses may increase myocardial oxygen consumption and induce arrhythmias, diastolic hypotension may reduce coronary perfusion and increase infarct size. OBJECTIVES: This study aimed to determine the optimal mean arterial pressure (MAP) in patients with AMI and shock after cardiac arrest. METHODS: This study used patient-level pooled analysis of post-cardiac arrest patients with shock after AMI randomized in the Neuroprotect (Neuroprotective Goal Directed Hemodynamic Optimization in Post-cardiac Arrest Patients; NCT02541591) and COMACARE (Carbon Dioxide, Oxygen and Mean Arterial Pressure After Cardiac Arrest and Resuscitation; NCT02698917) trials who were randomized to MAP 65 mm Hg or MAP 80/85 to 100 mm Hg targets during the first 36 h after admission. The primary endpoint was the area under the 72-h high-sensitivity troponin-T curve. RESULTS: Of 235 patients originally randomized, 120 patients had AMI with shock. Patients assigned to the higher MAP target (n = 58) received higher doses of norepinephrine (p = 0.004) and dobutamine (p = 0.01) and reached higher MAPs (86 ± 9 mm Hg vs. 72 ± 10 mm Hg, p < 0.001). Whereas admission hemodynamics and angiographic findings were all well-balanced and revascularization was performed equally effective, the area under the 72-h high-sensitivity troponin-T curve was lower in patients assigned to the higher MAP target (median: 1.14 µg.72 h/l [interquartile range: 0.35 to 2.31 µg.72 h/l] vs. median: 1.56 µg.72 h/l [interquartile range: 0.61 to 4.72 µg. 72 h/l]; p = 0.04). Additional pharmacologic support did not increase the risk of a new cardiac arrest (p = 0.88) or atrial fibrillation (p = 0.94). Survival with good neurologic outcome at 180 days was not different between both groups (64% vs. 53%, odds ratio: 1.55; 95% confidence interval: 0.74 to 3.22). CONCLUSIONS: In post-cardiac arrest patients with shock after AMI, targeting MAP between 80/85 and 100 mm Hg with additional use of inotropes and vasopressors was associated with smaller myocardial injury.

Near-infrared spectroscopy after out-of-hospital cardiac arrest.

BACKGROUND: Cerebral hypoperfusion may aggravate neurological damage after cardiac arrest. Near-infrared spectroscopy (NIRS) provides information on cerebral oxygenation but its relevance during post-resuscitation care is undefined. We investigated whether cerebral oxygen saturation (rSO2) measured with NIRS correlates with the serum concentration of neuron-specific enolase (NSE), a marker of neurological injury, and with clinical outcome in out-of-hospital cardiac arrest (OHCA) patients. METHODS: We performed a post hoc analysis of a randomised clinical trial (COMACARE, NCT02698917) comparing two different levels of carbon dioxide, oxygen and arterial pressure after resuscitation from OHCA with ventricular fibrillation as the initial rhythm. We measured rSO2 in 118 OHCA patients with NIRS during the first 36 h of intensive care. We determined the NSE concentrations from serum samples at 48 h after cardiac arrest and assessed neurological outcome with the Cerebral Performance Category (CPC) scale at 6 months. We evaluated the association between rSO2 and serum NSE concentrations and the association between rSO2 and good (CPC 1-2) and poor (CPC 3-5) neurological outcome. RESULTS: The median (inter-quartile range (IQR)) NSE concentration at 48 h was 17.5 (13.4-25.0) µg/l in patients with good neurological outcome and 35.2 (22.6-95.8) µg/l in those with poor outcome, p < 0.001. We found no significant correlation between median rSO2 and NSE at 48 h, rs = - 0.08, p = 0.392. The median (IQR) rSO2 during the first 36 h of intensive care was 70.0% (63.5-77.0%) in patients with good outcome and 71.8% (63.3-74.0%) in patients with poor outcome, p = 0.943. There was no significant association between rSO2 over time and neurological outcome. In a binary logistic regression model, rSO2 was not a statistically significant predictor of good neurological outcome (odds ratio 0.99, 95% confidence interval 0.94-1.04, p = 0.635). CONCLUSIONS: We found no association between cerebral oxygenation measured with NIRS and NSE concentrations or outcome in patients resuscitated from OHCA. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02698917 . Registered on 26 January 2016.

Targeting two different levels of both arterial carbon dioxide and arterial oxygen after cardiac arrest and resuscitation: a randomised pilot trial.

PURPOSE: We assessed the effects of targeting low-normal or high-normal arterial carbon dioxide tension (PaCO2) and normoxia or moderate hyperoxia after out-of-hospital cardiac arrest (OHCA) on markers of cerebral and cardiac injury. METHODS: Using a 23 factorial design, we randomly assigned 123 patients resuscitated from OHCA to low-normal (4.5-4.7 kPa) or high-normal (5.8-6.0 kPa) PaCO2 and to normoxia (arterial oxygen tension [PaO2] 10-15 kPa) or moderate hyperoxia (PaO2 20-25 kPa) and to low-normal or high-normal mean arterial pressure during the first 36 h in the intensive care unit. Here we report the results of the low-normal vs. high-normal PaCO2 and normoxia vs. moderate hyperoxia comparisons. The primary endpoint was the serum concentration of neuron-specific enolase (NSE) 48 h after cardiac arrest. Secondary endpoints included S100B protein and cardiac troponin concentrations, continuous electroencephalography (EEG) and near-infrared spectroscopy (NIRS) results and neurologic outcome at 6 months. RESULTS: In total 120 patients were included in the analyses. There was a clear separation in PaCO2 (p < 0.001) and PaO2 (p < 0.001) between the groups. The median (interquartile range) NSE concentration at 48 h was 18.8 µg/l (13.9-28.3 µg/l) in the low-normal PaCO2 group and 22.5 µg/l (14.2-34.9 µg/l) in the high-normal PaCO2 group, p = 0.400; and 22.3 µg/l (14.8-27.8 µg/l) in the normoxia group and 20.6 µg/l (14.2-34.9 µg/l) in the moderate hyperoxia group, p = 0.594). High-normal PaCO2 and moderate hyperoxia increased NIRS values. There were no differences in other secondary outcomes. CONCLUSIONS: Both high-normal PaCO2 and moderate hyperoxia increased NIRS values, but the NSE concentration was unaffected. REGISTRATION: ClinicalTrials.gov, NCT02698917. Registered on January 26, 2016.

Targeting low-normal or high-normal mean arterial pressure after cardiac arrest and resuscitation: a randomised pilot trial.

PURPOSE: We aimed to determine the feasibility of targeting low-normal or high-normal mean arterial pressure (MAP) after out-of-hospital cardiac arrest (OHCA) and its effect on markers of neurological injury. METHODS: In the Carbon dioxide, Oxygen and Mean arterial pressure After Cardiac Arrest and REsuscitation (COMACARE) trial, we used a 23 factorial design to randomly assign patients after OHCA and resuscitation to low-normal or high-normal levels of arterial carbon dioxide tension, to normoxia or moderate hyperoxia, and to low-normal or high-normal MAP. In this paper we report the results of the low-normal (65-75 mmHg) vs. high-normal (80-100 mmHg) MAP comparison. The primary outcome was the serum concentration of neuron-specific enolase (NSE) at 48 h after cardiac arrest. The feasibility outcome was the difference in MAP between the groups. Secondary outcomes included S100B protein and cardiac troponin (TnT) concentrations, electroencephalography (EEG) findings, cerebral oxygenation and neurological outcome at 6 months after cardiac arrest. RESULTS: We recruited 123 patients and included 120 in the final analysis. We found a clear separation in MAP between the groups (p < 0.001). The median (interquartile range) NSE concentration at 48 h was 20.6 µg/L (15.2-34.9 µg/L) in the low-normal MAP group and 22.0 µg/L (13.6-30.9 µg/L) in the high-normal MAP group, p = 0.522. We found no differences in the secondary outcomes. CONCLUSIONS: Targeting a specific range of MAP was feasible during post-resuscitation intensive care. However, the blood pressure level did not affect the NSE concentration at 48 h after cardiac arrest, nor any secondary outcomes.

Targeting low- or high-normal Carbon dioxide, Oxygen, and Mean arterial pressure After Cardiac Arrest and REsuscitation: study protocol for a randomized pilot trial.

BACKGROUND: Arterial carbon dioxide tension (PaCO2), oxygen tension (PaO2), and mean arterial pressure (MAP) are modifiable factors that affect cerebral blood flow (CBF), cerebral oxygen delivery, and potentially the course of brain injury after cardiac arrest. No evidence regarding optimal treatment targets exists. METHODS: The Carbon dioxide, Oxygen, and Mean arterial pressure After Cardiac Arrest and REsuscitation (COMACARE) trial is a pilot multi-center randomized controlled trial (RCT) assessing the feasibility of targeting low- or high-normal PaCO2, PaO2, and MAP in comatose, mechanically ventilated patients after out-of-hospital cardiac arrest (OHCA), as well as its effect on brain injury markers. Using a 23 factorial design, participants are randomized upon admission to an intensive care unit into one of eight groups with various combinations of PaCO2, PaO2, and MAP target levels for 36 h after admission. The primary outcome is neuron-specific enolase (NSE) serum concentration at 48 h after cardiac arrest. The main feasibility outcome is the between-group differences in PaCO2, PaO2, and MAP during the 36 h after ICU admission. Secondary outcomes include serum concentrations of NSE, S100 protein, and cardiac troponin at 24, 48, and 72 h after cardiac arrest; cerebral oxygenation, measured with near-infrared spectroscopy (NIRS); potential differences in epileptic activity, monitored via continuous electroencephalogram (EEG); and neurological outcomes at six months after cardiac arrest. DISCUSSION: The trial began in March 2016 and participant recruitment has begun in all seven study sites as of March 2017. Currently, 115 of the total of 120 patients have been included. When completed, the results of this trial will provide preliminary clinical evidence regarding the feasibility of targeting low- or high-normal PaCO2, PaO2, and MAP values and its effect on developing brain injury, brain oxygenation, and epileptic seizures after cardiac arrest. The results of this trial will be used to evaluate whether a larger RCT on this subject is justified. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02698917 . Registered on 26 January 2016.

[Update on current care guideline: sepsis (adults]. / Sepsis (aikuiset).

The incidence of severe sepsis and septic shock requiring intensive care in Finnish adult population has increased to 0.60 11000 /y. Despite improved prognosis, hospital mortality related to severe sepsis and septic shock is high 24.1%. Key recommendations include prompt administration of antimicrobial therapy, optimally after blood cultures, quantitative fluid resuscitation and imaging studies to identify possible source of infection. Crystalloids are suitable for fluid resuscitation. Norepinephrine is the first-choice vasopressor in septic shock. Hydrocortisone should be considered only if fluid and vasopressor treatment does not restore hemodynamics.

[Update on current care guidelines. Treatment of severe sepsis in adults]. / Aikuisten vaikean sepsiksen hoito.

According to the Finnsepsis Study, the incidence in Finland of severe sepsis requiring intensive care was 0.38/1,000 inhabitants/year. ICU and hospital mortality was 15.5% and 28.3%, respectively. The Finnsepsis Study showed that compliance with protocols was rather poor and antimicrobial treatment was often delayed. These guidelines emphasize the importance of prompt antibiotic and fluid therapy. In shock, norepinephrine is the first line vasopressor. Low-dose hydrocortisone may be used to shorten the need for vasopressors. Activated protein C should be considered in selected patients. The blood glucose target recommendation is between 5 and 8 mmol/l.

Free cortisol in sepsis and septic shock.

BACKGROUND: Severe sepsis activates the hypothalamopituitary axis, increasing cortisol production. In some studies, hydrocortisone substitution based on an adrenocorticotropic hormone-stimulation test or baseline cortisol measurement has improved outcome. Because only the free fraction of cortisol is active, measurement of free cortisol may be more important than total cortisol in critically ill patients. We measured total and free cortisol in patients with severe sepsis and related the concentrations to outcome. METHODS: In a prospective study, severe sepsis was defined according the American College of Chest Physicians/Society of Critical Care Medicine criteria. Blood samples were drawn within 24 h of study entry. Serum cortisol was analyzed by electrochemiluminescence immunoassay. The Coolens method was used for calculating serum free cortisol concentrations. RESULTS: Blood samples were collected from 125 patients, of whom 62 had severe sepsis and 63 septic shock. Hospital mortality was 21%. Calculated free serum cortisol correlated well with serum total cortisol (r = 0.90, P < 0.001). There was no difference in the total cortisol concentrations in patients with sepsis and septic shock (728 +/- 386 nmol/L vs 793 +/- 439 nmol/L, P = 0.44). Nonsurvivors had higher calculated serum free (209 +/- 151 nmol/L) and total (980 +/- 458 nmol/L) cortisol concentrations than survivors (119 +/- 111 nmol/L, P = 0.002, and 704 +/- 383 nmol/L, P = 0.002). Depending on the definition, the incidence of adrenal insufficiency varied from 8% to 54%. CONCLUSIONS: Clinically, calculation of free cortisol does not provide essential information for identification of patients who would benefit from corticoid treatment in severe sepsis and septic shock.

Effect of mode of hydrocortisone administration on glycemic control in patients with septic shock: a prospective randomized trial.

INTRODUCTION: Low-dose hydrocortisone treatment is widely accepted therapy for the treatment of vasopressor-dependent septic shock. The question of whether corticosteroids should be given to septic shock patients by continuous or by bolus infusion is still unanswered. Hydrocortisone induces hyperglycemia and it is possible that continuous hydrocortisone infusion would reduce the fluctuations in blood glucose levels and that tight blood glucose control could be better achieved with this approach. METHODS: In this prospective randomized study, we compared the blood glucose profiles, insulin requirements, amount of nursing workload needed, and shock reversal in 48 septic shock patients who received hydrocortisone treatment either by bolus or by continuous infusion with equivalent dose (200 mg/day). Duration of hydrocortisone treatment was five days. RESULTS: The mean blood glucose levels were similar in the two groups, but the number of hyperglycemic episodes was significantly higher in those patients who received bolus therapy (15.7 +/- 8.5 versus 10.5 +/- 8.6 episodes per patient, p = 0.039). Also, more changes in insulin infusion rate were needed to maintain strict normoglycemia in the bolus group (4.7 +/- 2.2 versus 3.4 +/- 1.9 adjustments per patient per day, p = 0.038). Hypoglycemic episodes were rare in both groups. No difference was seen in shock reversal. CONCLUSION: Strict normoglycemia is more easily achieved if the hydrocortisone therapy is given to septic shock patients by continuous infusion. This approach also reduces nursing workload needed to maintain tight blood glucose control.

A single adrenocorticotropic hormone stimulation test does not reveal adrenal insufficiency in septic shock.

The diagnosis of adrenocortical insufficiency in critically ill patients is complex. The adrenocorticotropic hormone (ACTH) stimulation test is a widely accepted method for assessing the adequacy of adrenal function in intensive care units, but it is possible that there may be wide variations in responses to the test over a short period of time. In this prospective study, we investigated the reproducibility of the ACTH stimulation test in 20 patients with sepsis, in 20 patients with septic shock, and in 20 critically ill patients without sepsis. Two consecutive ACTH stimulation tests were performed within 24 h after intensive care unit admission or at the onset of sepsis. In patients without sepsis there was good correlation between ACTH responses on days 1 and 2 (Pearson's correlation coefficient, 0.689; P = 0.001). In contrast, in patients with septic shock no correlation was observed between the two ACTH responses (Pearson's correlation coefficient, 0.401; P = 0.080). We conclude that the results of the ACTH stimulation tests are poorly reproducible in septic shock and a single ACTH stimulation test may not be the best method to diagnose adrenal insufficiency in these patients.