Renal function after out-of-hospital cardiac arrest; the influence of temperature management and coronary angiography, a post hoc study of the target temperature management trial.

BACKGROUND: To elucidate the incidence of acute kidney injury (AKI) after out-of-hospital cardiac arrest (OHCA) and to examine the impact of target temperature management (TTM) and early coronary angiography on renal function. METHODS: Post hoc analysis of the TTM trial, a multinational randomised controlled trial comparing target temperature of 33 °C versus 36 °C in patients with return of spontaneous circulation after OHCA. The impact of TTM and early angiography (within 6 h of OHCA) versus late or no angiography on the development of AKI during the 7-day period after OHCA was analysed. AKI was defined according to modified KDIGO criteria in patients surviving beyond day 2 after OHCA. RESULTS: Following exclusions, 853 of 939 patients enrolled in the main trial were analysed. Unadjusted analysis showed that significantly more patients in the 33 °C group had AKI compared to the 36 °C group [211/431 (49%) versus 170/422 (40%) p = 0.01], with a worse severity (p = 0.018). After multivariable adjustment, the difference was not significant (odds ratio 0.75, 95% confidence interval 0.54-1.06, p = 0.10]. Five hundred seventeen patients underwent early coronary angiography. Although the unadjusted analysis showed less AKI and less severe AKI in patients who underwent early angiography compared to patients with late or no angiography, in adjusted analyses, early angiography was not an independent risk factor for AKI (odds ratio 0.73, 95% confidence interval 0.50-1.05, p = 0.09). CONCLUSIONS: In OHCA survivors, TTM at 33 °C compared to management at 36 °C did not show different rates of AKI and early angiography was not associated with an increased risk of AKI. TRIAL REGISTRATION: NCT01020916 . Registered on www.ClinicalTrials.gov 26 November 2009 (main trial).

Dysglycemia, Glycemic Variability, and Outcome After Cardiac Arrest and Temperature Management at 33°C and 36°C.

OBJECTIVES: Dysglycemia and glycemic variability are associated with poor outcomes in critically ill patients. Targeted temperature management alters blood glucose homeostasis. We investigated the association between blood glucose concentrations and glycemic variability and the neurologic outcomes of patients randomized to targeted temperature management at 33°C or 36°C after cardiac arrest. DESIGN: Post hoc analysis of the multicenter TTM-trial. Primary outcome of this analysis was neurologic outcome after 6 months, referred to as "Cerebral Performance Category." SETTING: Thirty-six sites in Europe and Australia. PATIENTS: All 939 patients with out-of-hospital cardiac arrest of presumed cardiac cause that had been included in the TTM-trial. INTERVENTIONS: Targeted temperature management at 33°C or 36°C. MEASUREMENTS AND MAIN RESULTS: Nonparametric tests as well as multiple logistic regression and mixed effects logistic regression models were used. Median glucose concentrations on hospital admission differed significantly between Cerebral Performance Category outcomes (p < 0.0001). Hyper- and hypoglycemia were associated with poor neurologic outcome (p = 0.001 and p = 0.054). In the multiple logistic regression models, the median glycemic level was an independent predictor of poor Cerebral Performance Category (Cerebral Performance Category, 3-5) with an odds ratio (OR) of 1.13 in the adjusted model (p = 0.008; 95% CI, 1.03-1.24). It was also a predictor in the mixed model, which served as a sensitivity analysis to adjust for the multiple time points. The proportion of hyperglycemia was higher in the 33°C group compared with the 36°C group. CONCLUSION: Higher blood glucose levels at admission and during the first 36 hours, and higher glycemic variability, were associated with poor neurologic outcome and death. More patients in the 33°C treatment arm had hyperglycemia.

Protocol-driven neurological prognostication and withdrawal of life-sustaining therapy after cardiac arrest and targeted temperature management.

BACKGROUND: Brain injury is reportedly the main cause of death for patients resuscitated after out-of-hospital cardiac arrest (OHCA). However, the majority may actually die following withdrawal of life-sustaining therapy (WLST) with a presumption of poor neurological recovery. We investigated how the protocol for neurological prognostication was used and how related treatment recommendations might have affected WLST decision-making and outcome after OHCA in the targeted temperature management (TTM) trial. METHODS: Analyses of prospectively recorded data: details of neurological prognostication; recommended level-of-care; WLST decisions; presumed cause of death; and cerebral performance category (CPC) 6 months following randomization. RESULTS: Of 939 patients, 452 (48%) woke and 139 (15%) died, mostly for non-neurological reasons, before a scheduled time point for neurological prognostication (72h after the end of TTM). Three hundred and thirteen (33%) unconscious patients underwent prognostication at a median 117 (IQR 93-137) hours after arrest. Thirty-three (3%) unconscious patients were not neurologically prognosticated and for 2 patients (1%) data were missing. Related care recommendations were: continue in 117 (37%); not escalate in 55 (18%); and withdraw in 141 (45%). WLST eventually occurred in 196 (63%) at median day 6 (IQR 5-8). At 6 months, only 2 patients with WLST were alive and 248 (79%) of prognosticated patients had died. There were significant differences in time to WLST and death after the different recommendations (log rank <0.001). CONCLUSION: Delayed prognostication was relevant for a minority of patients and related to subsequent decisions on level-of-care with effects on ICU length-of-stay, survival time and outcome.

Validation of a classification system for causes of death in critical care: an assessment of inter-rater reliability.

OBJECTIVE: Trials in critical care have previously used unvalidated systems to classify cause of death. We aimed to provide initial validation of a method to classify cause of death in intensive care unit patients. DESIGN, SETTING AND PARTICIPANTS: One hundred case scenarios of patients who died in an ICU were presented online to raters, who were asked to select a proximate and an underlying cause of death for each, using the ICU Deaths Classification and Reason (ICU-DECLARE) system. We evaluated two methods of categorising proximate cause of death (designated Lists A and B) and one method of categorising underlying cause of death. Raters were ICU specialists and research coordinators from Australia, New Zealand and the United Kingdom. MAIN OUTCOME MEASURES: Inter-rater reliability, as measured by the Fleiss multirater kappa, and the median proportion of raters choosing the most likely diagnosis (defined as the most popular classification choice in each case). RESULTS: Across all raters and cases, for proximate cause of death List A, kappa was 0.54 (95% CI, 0.49-0.60), and for proximate cause of death List B, kappa was 0.58 (95% CI, 0.53-0.63). For the underlying cause of death, kappa was 0.48 (95% CI, 0.44-0.53). The median proportion of raters choosing the most likely diagnosis for proximate cause of death, List A, was 77.5% (interquartile range [IQR], 60.0%-93.8%), and the median proportion choosing the most likely diagnosis for proximate cause of death, List B, was 82.5% (IQR, 60.0%-92.5%). The median proportion choosing the most likely diagnosis for underlying cause was 65.0% (IQR, 50.0%-81.3%). Kappa and median agreement were similar between countries. ICU specialists showed higher kappa and median agreement than research coordinators. CONCLUSIONS: The ICU-DECLARE system allowed ICU doctors to classify the proximate cause of death of patients who died in the ICU with substantial reliability.

Neurologic Function and Health-Related Quality of Life in Patients Following Targeted Temperature Management at 33°C vs 36°C After Out-of-Hospital Cardiac Arrest: A Randomized Clinical Trial.

IMPORTANCE: Brain injury affects neurologic function and quality of life in survivors after cardiac arrest. OBJECTIVE: To compare the effects of 2 target temperature regimens on long-term cognitive function and quality of life after cardiac arrest. DESIGN, SETTING, AND PARTICIPANTS: In this multicenter, international, parallel group, assessor-masked randomized clinical trial performed from November 11, 2010, through January 10, 2013, we enrolled 950 unconscious adults with cardiac arrest of presumed cardiac cause from 36 intensive care units in Europe and Australia. Eleven patients were excluded from analysis for a total sample size of 939. INTERVENTIONS: Targeted temperature management at 33°C vs 36°C. MAIN OUTCOMES AND MEASURES: Cognitive function was measured by the Mini-Mental State Examination (MMSE) and assessed by observers through the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE). Patients reported their activities in daily life and mental recovery through Two Simple Questions and their quality of life through the Medical Outcomes Study 36-Item Short Form Health Survey, version 2. RESULTS: In the modified intent-to-treat population, including nonsurvivors, the median MMSE score was 14 in the 33°C group (interquartile range [IQR], 0-28) vs 17 in the 36°C group (IQR, 0-29) (P = .77), and the IQCODE score was 115 (IQR, 79-130) vs 115 (IQR, 80-130) (P = .57) in the 33°C and 36°C groups, respectively. The median MMSE score for survivors was within the reference range and similar (33°C group median, 28; IQR, 26-30; vs 36°C group median, 28; IQR, 25-30; P = .61). The median IQCODE score was within the minor deficit range (33°C group median, 79.5; IQR, 78.0-85.9; vs 36°C group median, 80.7; IQR, 78.0-86.9; P = .04). A total of 18.8% vs 17.5% of survivors reported needing help with everyday activities (P = .71), and 66.5% in the 33°C group vs 61.8% in the 36°C group reported that they thought they had made a complete mental recovery (P = .32). The mean (SD) mental component summary score was 49.1 (12.5) vs 49.0 (12.2) (P = .79), and the mean (SD) physical component summary score was 46.8 (13.8) and 47.5 (13.8) (P = .45), comparable to the population norm. CONCLUSIONS AND RELEVANCE: Quality of life was good and similar in patients with cardiac arrest receiving targeted temperature management at 33°C or 36°C. Cognitive function was similar in both intervention groups, but many patients and observers reported impairment not detected previously by standard outcome scales. TRIAL REGISTRATION: ClinicalTrials.gov NCT01020916.

Target Temperature Management after out-of-hospital cardiac arrest--a randomized, parallel-group, assessor-blinded clinical trial--rationale and design.

BACKGROUND: Experimental animal studies and previous randomized trials suggest an improvement in mortality and neurologic function with induced hypothermia after cardiac arrest. International guidelines advocate the use of a target temperature management of 32°C to 34°C for 12 to 24 hours after resuscitation from out-of-hospital cardiac arrest. A systematic review indicates that the evidence for recommending this intervention is inconclusive, and the GRADE level of evidence is low. Previous trials were small, with high risk of bias, evaluated select populations, and did not treat hyperthermia in the control groups. The optimal target temperature management strategy is not known. METHODS: The TTM trial is an investigator-initiated, international, randomized, parallel-group, and assessor-blinded clinical trial designed to enroll at least 850 adult, unconscious patients resuscitated after out-of-hospital cardiac arrest of a presumed cardiac cause. The patients will be randomized to a target temperature management of either 33°C or 36°C after return of spontaneous circulation. In both groups, the intervention will last 36 hours. The primary outcome is all-cause mortality at maximal follow-up. The main secondary outcomes are the composite outcome of all-cause mortality and poor neurologic function (cerebral performance categories 3 and 4) at hospital discharge and at 180 days, cognitive status and quality of life at 180 days, assessment of safety and harm. DISCUSSION: The TTM trial will investigate potential benefit and harm of 2 target temperature strategies, both avoiding hyperthermia in a large proportion of the out-of-hospital cardiac arrest population.

Exhaled breath condensate detects markers of pulmonary inflammation after cardiothoracic surgery.

Cardiac surgery using cardiopulmonary by-pass and, to a greater extent, lung resection, causes acute lung injury that is usually subclinical. Analysis of mediators in exhaled breath condensate is a promising means of monitoring inflammation in a variety of airway diseases but the contribution of the airway lining fluid from the lower respiratory tract is uncertain. We compared the analysis of markers of lung injury in exhaled breath condensate and bronchoalveolar lavage in endotracheally intubated patients before and after coronary artery bypass graft surgery with cardiopulmonary bypass and lobectomy. The neutrophil count and leukotriene B4 concentration in bronchoalveolar lavage fluid rose after coronary artery bypass graft surgery (p < 0.05), but there was no significant change in leukotriene B4, hydrogen peroxide, or hydrogen ion concentrations in exhaled breath condensate. By contrast, after lobectomy, the concentration in exhaled breath condensate of leukotriene B4, hydrogen peroxide and hydrogen ions rose significantly (p < 0.05). Exhaled breath condensate is a safe, noninvasive method of sampling the milieu of the distal lung and is sufficiently sensitive to detect markers of inflammation and oxidative stress in patients after lobectomy, but not after the milder insult associated with cardiac surgery.