Outcomes of hanging-induced cardiac arrest patients who underwent therapeutic hypothermia: A multicenter retrospective cohort study

Objectives

The aim of this study was to analyze the outcomes of patients with hanging-induced cardiac arrest who underwent therapeutic hypothermia (TH).

Method

In this multicenter, retrospective registry-based study, discharged patients after out-of-hospital cardiac arrest and treatment with TH were enrolled between June 2007 and March 2013. Several prehospital and hospital variables were examined for an outcome analysis with multivariable logistic regression.

Results

A total of 964 patients who had cardiac arrest were enrolled in this study. All patients underwent TH during post-cardiac arrest care after return of spontaneous circulation (ROSC). Of all patients, 105 were assigned to the hanging group and 859 to the non-hanging group. Six patients (6%) with good neurologic outcomes (Cerebral Performance Category 1 or 2) in the hanging group at the time of discharge were found. A shorter time interval between witnessed arrest and ROSC and a Glasgow Coma Scale over 4 after ROSC are statistically significant variables of good neurologic outcomes after hanging-induced cardiac arrest treated with TH.

Conclusion

A small number of patients who underwent TH after a hanging-induced cardiac arrest provided good neurologic outcomes, and some variables influenced these outcomes.     

The prognostic value of continuous amplitude-integrated electroencephalogram applied immediately after return of spontaneous circulation in therapeutic hypothermia-treated cardiac arrest patients

Introduction

The purpose of this study was to examine the prognostic value of continuous amplitude-integrated electroencephalogram (aEEG) applied immediately after return of spontaneous circulation (ROSC) in therapeutic hypothermia (TH)-treated cardiac arrest patients.

Methods

From September 2010 to August 2011, we prospectively studied comatose patients treated with TH after cardiac arrest who were monitored with aEEG. Monitoring at the forehead was applied as soon as possible after ROSC in the emergency department and continued until recovery of consciousness, death, or 72 h after ROSC. Neurological outcome was assessed with the Cerebral Performance Category (CPC) scale at hospital discharge, and good neurological outcome was defined as a CPC score of 1 or 2.

Results

A total of 55 TH-treated patients were included. Monitoring started at a median of 96 min after ROSC (interquartile range, 49–174). At discharge, 28 patients had a CPC of 1–2, and 27 patients had a CPC of 3–5. Seventeen patients had a continuous normal voltage (CNV) trace at the start of monitoring, and this voltage was strongly associated with a good outcome (16/17 [94.1%]; sensitivity and specificity of 57.1 and 96.3%, respectively). No development of a CNV trace within the recorded period accurately predicted a poor outcome (21/21 [100%]; sensitivity and specificity of 77.8 and 100%, respectively).

Conclusions

An initial CNV trace in aEEG applied to forehead immediately after ROSC is a good early predictor of a good outcome in TH-treated cardiac arrest patients. Conversely, no development of a CNV trace within 72 h is an accurate and reliable predictor of a poor outcome with a false-positive rate of 0%.     

A history of smoking is associated with improved survival in patients treated with mild therapeutic hypothermia following cardiac arrest

Objectives

To assess the association between smoking and survival with a good neurologic outcome in patients following cardiac arrest treated with mild therapeutic hypothermia (TH).

Methods

We conducted a retrospective observational study of a prospectively collected cohort of 188 consecutive patients following cardiac arrest treated with TH between May 2007 and January 2012. Smoking status was retrospectively collected via chart review and was classified as “ever” or “never”. Primary endpoint was survival to hospital discharge with a good neurologic outcome and was compared between smokers and nonsmokers. Logistic regression analysis was used to assess the association between smoking status and neurologic outcome at hospital discharge; adjusting for age, initial rhythm, time to return of spontaneous circulation (ROSC), bystander CPR, and time to initiation of TH.

Results

Smokers were significantly more likely to survive to hospital discharge with good neurologic outcome compared to nonsmokers (50% vs. 28%, p = 0.003). After adjusting for age, initial rhythm, time to ROSC, bystander CPR, and time to initiation of TH, a history of smoking was associated with increased odds of survival to hospital discharge with good neurologic outcome (OR 3.54, 95% CI 1.41–8.84, p = 0.007).

Conclusions

Smoking is associated with improved survival with good neurologic outcome in patients following cardiac arrest. We hypothesize that our findings reflect global ischemic conditioning caused by smoking.     

Neurologic outcome in comatose patients resuscitated from out-of-hospital cardiac arrest with prolonged downtime and treated with therapeutic hypothermia

Background

Previous reports have shown that prolonged duration of resuscitation efforts in out-of-hospital cardiac arrest (OHCA) is associated with poor neurologic outcome. This concept has recently been questioned with advancements in post-cardiac arrest care including the use of therapeutic hypothermia (TH). The aim of this study was to determine the rate of good neurologic outcome based on the duration of resuscitation efforts in OHCA patients treated with TH.

Methods

This prospective, observational, study was conducted between January 2008 and September 2012. Inclusion criteria consisted of adult non-traumatic OHCA patients who were comatose after return of spontaneous circulation (ROSC) and received TH. The primary endpoint was good neurologic outcome defined as a cerebral performance category score of 1 or 2. Downtime was calculated as the length of time between the patient being recognized as pulseless and ROSC.

Results

105 patients were treated with TH and 19 were excluded due to unknown downtime, leaving 86 patients for analysis. The median downtime was 18.5 (10.0–32.3) min and 33 patients (38.0%) had a good neurologic outcome. When downtime was divided into four groups (≤10 min, 11–20 min, 21–30 min, >30 min), good neurologic outcomes were 62.5%, 37%, 25%, and 21.7%, respectively (p = 0.02). However, even with downtime >20 min, 22.9% had a good neurologic outcome, and this percentage increased to 37.5% in patients with an initial shockable rhythm.

Conclusions

Although longer downtime is associated with worse outcome in OHCA patients, we found that comatose patients who have been successfully resuscitated and treated with TH have neurologically intact survival rates of 23% even with downtime >20 min.     

The association between a quantitative computed tomography (CT) measurement of cerebral edema and outcomes in post-cardiac arrest—A validation study

Aim

Previous studies have examined the association between quantitative head computed tomography (CT) measures of cerebral edema and patient outcomes reporting that a calculated gray matter to white matter attenuation ratio (GWR) of <1.2 indicates a near 100% non-survivable injury post-cardiac arrest. The objective of the current study was to validate whether a GWR <1.2 reliably indicates poor survival post-cardiac arrest. We also sought to determine the inter-rater variability among reviewers, and examine the utility of a novel GWR measurement to facilitate easier practical use.

Methods

We performed a retrospective analysis of post-cardiac arrest patients admitted to a single center from 2008 to 2012. Inclusion criteria were age ≥18 years, non-traumatic arrest, and available CT imaging within 24 h after ROSC. Three independent physician reviewers from different specialties measured CT attenuation of pre-specified gray and white matter areas for GWR calculations.

Results

Out of 171 consecutive patients, 90 met the study inclusion criteria. Thirteen patients were excluded for technical reasons and/or significant additional pathology, leaving 77 head CT scans for evaluation. Median age was 66 years and 64% were male. In-hospital mortality was 65% and 70% of patients received therapeutic hypothermia. For the validation measurement, the intra-class correlation coefficient was 0.70. In our dataset, a GWR below 1.2 did not accurately predict mortality or poor neurological outcome (sensitivity 0.56–0.62 and specificity 0.63–0.81). A score below 1.1 predicted a near 100% mortality but was not a sensitive metric (sensitivity 0.14–0.20 and specificity 0.96–1.00). Similar results were found for the exploratory model.

Conclusion

A GWR <1.2 on CT imaging within 24 h after cardiac arrest was moderately specific for poor neurologic outcome and mortality. Based on our data, a threshold GWR <1.1 may be a safer cut-off to identify patients with low chance of survival and good neurological outcome. Intra-class correlation among reviewers was moderately good.     

Therapeutic hypothermia and vasopressor dependency after cardiac arrest

Objective

Clinical trials of therapeutic hypothermia (TH) after cardiac arrest excluded patients with persistent hemodynamic instability after return of spontaneous circulation (ROSC), and thus equipoise may exist regarding use of TH in these patients. Our objective was to determine if TH is associated with worsening hemodynamic instability among patients who are vasopressor-dependent after ROSC.

Methods

We performed a prospective observational study in vasopressor-dependent post-cardiac arrest patients. Inclusion criteria were age >17, non-trauma cardiac arrest, comatose after ROSC, and persistent vasopressor dependence. The decision to initiate TH (33–34 °C) was made by the treating physician. We measured cumulative vasopressor index (CVI) and mean arterial pressure (MAP) every 15 min during the first 6 h after ROSC. The outcome measures were change in CVI (primary outcome) and MAP (secondary outcome) over time. We graphed median CVI and MAP over time for the treated and not treated cohorts, and used propensity adjusted repeated measures mixed models to test for an association between TH induction and change in CVI or MAP over time.

Results

Seventy-five post-cardiac arrest patients were included (35 treated; 40 not treated). We observed no major differences in CVI or MAP over time between the treated and not treated cohorts. In the mixed models we found no statistically significant association between TH induction and changes in CVI or MAP.

Conclusion

In patients with vasopressor-dependency after cardiac arrest, the induction of hypothermia was not associated with a decrease in mean arterial pressure or increase in vasopressor requirement.     

S-100B is superior to NSE, BDNF and GFAP in predicting outcome of resuscitation from cardiac arrest with hypothermia treatment

Objective

To conduct a pilot study to evaluate the blood levels of brain derived neurotrophic factor (BDNF), glial fibrillary acidic protein (GFAP), neuron specific enolase (NSE) and S-100B as prognostic markers for neurological outcome 6 months after hypothermia treatment following resuscitation from cardiac arrest.

Design

Prospective observational study.

Setting

One intensive care unit at Uppsala University Hospital.

Patients

Thirty-one unconscious patients resuscitated after cardiac arrest.

Interventions

None.

Measurements and main results

Unconscious patients after cardiac arrest with restoration of spontaneous circulation (ROSC) were treated with mild hypothermia to 32-34 °C for 26 h. Time from cardiac arrest to target temperature was measured. Blood samples were collected at intervals of 1-108 h after ROSC. Neurological outcome was assessed with Glasgow-Pittsburgh cerebral performance category (CPC) scale at discharge from intensive care and again 6 months later, when 15/31 patients were alive, of whom 14 had a good outcome (CPC 1-2). Among the predictive biomarkers, S-100B at 24 h after ROSC was the best, predicting poor outcome (CPC 3-5) with a sensitivity of 87% and a specificity of 100%. NSE at 96 h after ROSC predicted poor outcome, with sensitivity of 57% and specificity of 93%. BDNF and GFAP levels did not predict outcome. The time from cardiac arrest to target temperature was shorter for those with poor outcome.

Conclusions

The blood concentration of S-100B at 24 h after ROSC is highly predictive of outcome in patients treated with mild hypothermia after cardiac arrest.     

Effects of variation in temperature management on cerebral performance category scores in patients who received therapeutic hypothermia post cardiac arrest

Aim

To assess differences in cerebral performance category (CPC) in patients who received therapeutic hypothermia post cardiac arrest by time to initiation, time to target temperature, and duration of therapeutic hypothermia (TH).

Methods

A secondary data analysis was conducted using hospital-specific data from the international cardiac arrest registry (INTCAR) database. The analytic sample included 172 adult patients who experienced an out-of-hospital cardiac arrest and were treated in one Midwestern hospital. Measures included time from arrest to ROSC, arrest to TH, arrest to target temperature, and length of time target temperature was maintained. CPC was assessed at three points: transfer from ICU, discharge from hospital, and post discharge follow-up.

Results

Average age was 63.6 years and 74.4% of subjects were male. Subjects had TH initiation a mean of 94.4 min (SD 81.6) after cardiac arrest and reached target temperature after 309.0 min (SD 151.0). In adjusted models, the odds of a poor neurological outcome increased with each 5 min delay in initiating TH at transfer from ICU (OR = 1.06, 95% C.I. 1.02–1.10). Similar results were seen for neurological outcomes at hospital discharge (OR = 1.06, 95% C.I. 1.02–1.11) and post-discharge follow-up (OR = 1.08, 95% C.I. 1.03–1.13). Additionally the odds of a poor neurological outcome increased for every 30 min delay in time to target temperature at post-discharge follow-up (OR = 1.17, 95% C.I. 1.01–1.36).

Conclusion

In adults undergoing TH post cardiac arrest, delay in initiation of TH and reaching target temperature differentiated poor versus good neurologic outcomes. Randomized trials assessing the range of current recommended guidelines for TH should be conducted to establish optimal treatment protocols.     

The occurrence of shivering in cardiac arrest survivors undergoing therapeutic hypothermia is associated with a good neurologic outcome

Background

The incidence of shivering in cardiac arrest survivors who undergo therapeutic hypothermia (TH) is varied. Its occurrence is dependent on the integrity of multiple peripheral and central neurologic pathways. We hypothesized that cardiac arrest survivors who develop shivering while undergoing TH are more likely to have intact central neurologic pathways and thus have better neurologic outcome as compared to those who do not develop shivering during TH.

Methods

Prospectively collected data on consecutive adult patients admitted to a tertiary center from 1/1/2007 to 11/1/2010 that survived a cardiac arrest and underwent TH were retrospectively analyzed. Patients who developed shivering during the cooling phase of TH formed the “shivering” group and those that did not formed the “non-shivering” group. The primary end-point: Pittsburgh Cerebral Performance Category (CPC) scale; good (CPC 1–2) or poor (CPC 3–5) neurological outcome prior to discharge from hospital.

Results

Of the 129 cardiac arrest survivors who underwent TH, 34/94 (36%) patients in the “non-shivering” group as compared to 21/35 (60%) patients in the “shivering” group had good neurologic outcome (P = 0.02). After adjusting for confounders using binary logistic regression, occurrence of shivering (OR: 2.71, 95% CI 1.099–7.41, P = 0.04), time to return of spontaneous circulation (OR: 0.96, 95% CI 0.93–0.98, P = 0.004) and initial presenting rhythm (OR: 4.0, 95% CI 1.63–10.0, P = 0.002) were independent predictors of neurologic outcome.

Conclusion

The occurrence of shivering in cardiac arrest survivors who undergo TH is associated with an increased likelihood of good neurologic outcome as compared to its absence.     

Testosterone related good neurologic outcome on the patients with return of spontaneous circulation after cardiac arrest: A prospective cohort study

Aim

To evaluate the gonadal hormones in patients with return of spontaneous circulation (ROSC) after cardiac arrest following prospectively good (cerebral-performance category [CPC] 1-2) and poor (CPC 3-5) neurologic outcomes.

Methods

The patients in an emergency center who had been admitted to the center's intensive care unit (ICU) after successful resuscitation following out-of-hospital cardiac arrest were prospectively identified and evaluated within the period from April 2008 to March 2011. The gonadal hormones, including progesterone, total estrogen, and testosterone, were measured and analyzed following the good and poor neurologic outcomes.

Results

A total of 142 patients were analyzed in this study. Thirty-nine (27.5%) patients had good neurologic outcomes. The gonadal hormones (progesterone, total estrogen, and testosterone) had good vs. poor neurologic outcomes of 1.039 ± 0.694 vs. 1.000 ± 0.892 ng/ml, 107.956 ± 13.163 vs. 117.060 ± 11.344 pg/ml, and 307.380 ± 33.844 vs. 189.020 ± 17.406 ng/dl, respectively. In the multiple logistic-regression analysis, the initial shockable rhythm (5.671 odds ratio [OR], 2.307-13.942 95% confidence interval [CI]), time from arrest to ROSC (0.957 OR, 0.933-0.982 95% CI), and more than 300 ng/dl of testosterone level (3.279 OR, 1.265-8.190 95% CI) were found to be related to good neurologic outcome, respectively.

Conclusion

Higher testosterone levels are related to good neurologic outcome at six months after admission in patients with spontaneous circulation after cardiac arrest. The testosterone levels may be useful prognostic tools for the postcardiac-arrest syndrome and could be used for the latter's neuroprotective treatment, but additional randomized controlled studies are needed.     

Neuron specific enolase and S-100B as predictors of outcome after cardiac arrest and induced hypothermia

Aim

To assess the prognostic value of repetitive serum samples of neuron specific enolase (NSE) and S-100B in cardiac arrest patients treated with hypothermia.

Methods

In a three-centre study, comatose patients after cardiac arrest were treated with hypothermia at 33 °C for 24 h, regardless of cause or the initial rhythm. Serum samples were collected at 2, 24, 48 and 72 h after the arrest and analysed for NSE and S-100B in a non-blinded way. The cerebral performance categories scale (CPC) was used as the outcome measure; a best CPC of 1–2 during 6 months was regarded as a good outcome, a best CPC of 3–5 a poor outcome.

Results

One centre was omitted in the NSE analysis due to missing 24 and 48 h samples. Two partially overlapping groups were studied, the NSE group (n = 102) and the S-100B group (n = 107). NSE at 48 h >28 μg/l (specificity 100%, sensitivity 67%) and S-100B >0.51 μg/l at 24 h (specificity 96%, sensitivity 62%) correlated with a poor outcome, and so did a rise in NSE of >2 μg/l between 24 and 48 h (odds ratio 9.8, CI 3.5–27.7). A majority of missing samples (n = 123) were from the 2 h sampling time (n = 56) due to referral from other hospitals or inter-hospital transfer.

Conclusion

NSE was a better marker than S-100B for predicting outcome after cardiac arrest and induced hypothermia. NSE above 28 μg/l at 48 h and a rise in NSE of more than 2 μg/l between 24 and 48 h were markers for a poor outcome.     

Prevalence and effect of fever on outcome following resuscitation from cardiac arrest

Objective

Evaluate the prevalence of fever in the first 48 h after cardiac arrest and its effect on outcomes.

Methods

Review of patients treated between 1/1/2005 and 6/30/2010. Fever was defined as T ≥ 38.0 °C. We classified categories of post-cardiac arrest illness severity as (I) awake, (II) coma + mild cardiopulmonary dysfunction (SOFA cardiac + respiratory score <4), (III) coma + moderate-severe cardiopulmonary dysfunction, and (IV) deep coma. Associations between fever and survival or good neurologic outcome were examined between hypothermia (TH) and non-TH groups.

Results

In 336 patients, mean age was 60 years (SD 16), 63% experienced out-of-hospital cardiac arrest and 65% received TH. A shockable rhythm was present in 40%. Post arrest illness severity was category II in 38%, category III in 20%, and category IV in 42%. Fever was present in 42% of subjects, with a post-arrest median onset of 15 h in the non-TH cohort and 36 h in TH cohort. Fever was not associated with survival within the whole cohort (OR 0.32, CI 0.15, 0.68) or TH cohort (OR 1.21, CI 0.69, 2.14), but was associated with survival in non-TH cohort (OR 0.47, CI 0.20, 1.10). Fever was not associated with good outcomes in the whole cohort (OR 0.83, CI 0.49, 1.40), TH cohort (OR 1.09, CI 0.56, 2.12) or non-TH cohort (OR 0.34, CI 0.11, 1.06).

Conclusions

The development of fever within the first 48 h after ROSC is common. Fever is associated with death in non-TH patients. TH treatment appears to mitigate this effect, perhaps by delaying fever onset.     

Prophylactic lidocaine for post resuscitation care of patients with out-of-hospital ventricular fibrillation cardiac arrest

Background

Antiarrhythmic drugs like lidocaine are usually given to promote return of spontaneous circulation (ROSC) during ongoing out-of-hospital cardiac arrest (OHCA) from ventricular fibrillation/tachycardia (VF/VT). Whether administering such drugs prophylactically for post-resuscitation care after ROSC prevents re-arrest and improves outcome is unstudied.

Methods

We evaluated a cohort of 1721 patients with witnessed VF/VT OHCA who did (1296) or did not receive prophylactic lidocaine (425) at first ROSC. Study endpoints included re-arrest, hospital admission and survival.

Results

Prophylacic lidocaine recipients and non-recipients were comparable, except for shorter time to first ROSC and higher systolic blood pressure at ROSC in those receiving lidocaine. After initial ROSC, arrest from VF/VT recurred in 16.7% and from non-shockable arrhythmias in 3.2% of prophylactic lidocaine recipients, 93.5% of whom were admitted to hospital and 62.4% discharged alive, as compared with 37.4%, 7.8%, 84.9% and 44.5%, of corresponding non-recipients (all p < 0.0001). Adjusted for pertinent covariates, prophylactic lidocaine was independently associated with reduced odds of re-arrest from VF/VT, odds ratio, (95% confidence interval) 0.34 (0.26–0.44) and from nonshockable arrhythmias (0.47 (0.29–0.78)); a higher hospital admission rate (1.88, (1.28–2.76)) and improved survival to discharge (1.49 (1.15–1.95)). However in a propensity score-matched sensitivity analysis, lidocaine's only beneficial association with outcome was in a lower incidence of recurrent VF/VT arrest.

Conclusions

Administration of prophylactic lidocaine upon ROSC after OHCA was consistently associated with less recurrent VF/VT arrest, and therapeutic equipoise for other measures. The prospect of a promising association between lidocaine prophylaxis and outcome, without evidence of harm, warrants further investigation.     

Low apparent diffusion coefficient cluster-based analysis of diffusion-weighted MRI for prognostication of out-of-hospital cardiac arrest survivors

Objective

Recent studies suggested quantitative analysis of diffusion-weighted magnetic resonance imaging as a promising tool for early prognostication of cardiac arrest patients. However, most of their methods involve significant manual image handling often subjective and difficult to reproduce. Therefore developing a computerized analysis method using easy-to-define characteristics would be useful.

Methods

Comatose out-of-hospital cardiac arrest (OHCA) patients who underwent brain MRI between January 2008 and July 2012 were identified from an OHCA registry. Apparent diffusion coefficient (ADC) axial images were analyzed using a program to detect and characterize clusters of low ADC pixels from six brain regions including frontal, occipital, parietal, rolandic and temporal and basal ganglia region. Identified clusters were ranked according to size, mean ADC and minimum ADC to assess the regional maximum cluster size (MCS), lowest mean ADC (LMEAN) and lowest minimum ADC (LMIN). Their power to predict poor outcome, defined as 6-month CPC 3 or higher, was assessed by contingency table analyses.

Results

51 OHCA patients were eligible during the study period. The sensitivities of MCS, LMEAN and LMIN to detect poor outcome varied according to brain region from 62.5 to 90.0%, 50.0 to 72.5% and 42.5 to 82.5% with their specificities set to 100%, respectively. The MCS of occipital region showed most favorable test profile (sensitivity 90%, specificity 100%; AUROC 0.940, 95% confidence interval 0.874–1.000).

Conclusion

The cluster-based computerized image analysis might be a simple but useful method for prediction of poor neurologic outcome. Future studies validating its prognostic performance are required.     

Post-cardiac arrest serum levels of glial fibrillary acidic protein for predicting neurological outcome

Aim of the study

To investigate serum levels of glial fibrillary acidic protein (GFAP) for evaluation of neurological outcome in cardiac arrest (CA) patients and compare GFAP sensitivity and specificity to that of more studied biomarkers neuron-specific enolas (NSE) and S100B.

Method

A prospective observational study was performed in three hospitals in Sweden during 2008-2012. The participants were 125 CA patients treated with therapeutic hypothermia (TH) to 32-34 °C for 24 hours. Samples were collected from peripheral blood (n = 125) and the jugular bulb (n = 47) up to 108 hours post-CA. GFAP serum levels were quantified using a novel, fully automated immunochemical method. Other biomarkers investigated were NSE and S100B. Neurological outcome was assessed using the Cerebral Performance Categories scale (CPC) and dichotomized into good and poor outcome.

Results

GFAP predicted poor neurological outcome with 100% specificity and 14-23% sensitivity at 24, 48 and 72 hours post-CA. The corresponding values for NSE were 27-50% sensitivity and for S100B 21-30% sensitivity when specificity was set to 100%. A logistic regression with stepwise combination of the investigated biomarkers, GFAP, did not increase the ability to predict neurological outcome. No differences were found in GFAP, NSE and S100B levels when peripheral and jugular bulb blood samples were compared.

Conclusion

Serum GFAP increase in patients with poor outcome but did not show sufficient sensitivity to predict neurological outcome after CA. Both NSE and S100B were shown to be better predictors. The ability to predict neurological outcome did not increased when combining the three biomarkers.     

Emergency Department inter-hospital transfer for post-cardiac arrest care: Initial experience with implementation of a regional cardiac resuscitation center in the United States

Objective

The American Heart Association recently recommended regional cardiac resuscitation centers (CRCs) for post-resuscitation care following out-of-hospital cardiac arrest (OHCA). Our objective was to describe initial experience with CRC implementation.

Methods

Prospective observational study of consecutive post-resuscitation patients transferred from community Emergency Departments (EDs) to a CRC over 9 months. Transfer criteria were: OHCA, return of spontaneous circulation (ROSC), and comatose after ROSC. Incoming patients were received and stabilized in the ED of the CRC where advanced therapeutic hypothermia (TH) modalities were applied. Standardized post-resuscitation care included: ED evaluation for cardiac catheterization, TH (33–34 °C) for 24 h, 24 h/day critical care physician support, and evidence-based neurological prognostication. Prospective data collection utilized the Utstein template. The primary outcome was survival to hospital discharge with good neurological function [Cerebral Performance Category 1 or 2].

Results

Twenty-seven patients transferred from 11 different hospitals were included. The majority (21/27 [78%]) had arrest characteristics suggesting poor prognosis for survival (i.e. asystole/pulseless electrical activity initial rhythm, absence of bystander cardiopulmonary resuscitation, or an unwitnessed cardiac arrest). The median (IQR) time from transfer initiation to reaching TH target temperature was 7 (5–13) h. Ten (37%) patients survived to hospital discharge, and of these 9/10 (90% of survivors, 33% of all patients) had good neurological function.

Conclusions

Despite a high proportion of patients with cardiac arrest characteristics suggesting poor prognosis for survival, we found that one-third of CRC transfers survived with good neurological function. Further research to determine if regional CRCs improve outcomes after cardiac arrest is warranted.     

Outcome and adverse events with 72-hour cooling at 32°C as compared to 24-hour cooling at 33°C in comatose asphyxial arrest survivors

Purpose

Studies suggest that the current therapeutic hypothermia (TH) protocol does not improve outcomes in adult asphyxial arrest survivors. We sought to compare the effect of 24-hour cooling at 33°C vs that of 72-hour cooling at 32°C on outcomes and the incidence of adverse events in unconscious asphyxial arrest survivors.

Methods

Retrospectively collected data on 79 consecutive asphyxial arrest patients treated with TH from January 2006 to March 2013 were analyzed. Forty-one patients who presented between January 2006 and January 2011 formed the 33°C-24 h group, whereas 38 patients who presented between February 2011 and March 2013 formed the 32°C-72 h group. The primary outcome was neurologic outcome at 30 days following arrest. The secondary outcomes were all-cause mortality at 30 days following arrest and the incidence of adverse events.

Results

The Kaplan-Meier curve showed no significant difference in survival over time during the 30 days after arrest between the 2 groups (P = .608). Good neurologic outcome was achieved in only 2 patients (2.5%) of the overall cohort, despite TH. One of the 32°C-72 h group (2.6%; 95% confidence interval, 4.7%-13.5%) had a good neurologic outcome, as did one of the 33°C-24 h group (2.4%; 95% confidence interval, 4.3%-12.6%) (P = 1.000). There were no significant differences in the rates of adverse events between the 2 groups.

Conclusion

The present study did not demonstrate an advantage of 72-hour cooling at 32°C in unconscious asphyxial arrest patients compared with 24-hour cooling at 33°C.     

Procalcitonin after cardiac arrest – An indicator of severity of illness,ischemia-reperfusion injury and outcome

Aim

To investigate serial serum concentrations of procalcitonin (PCT) and C-reactive protein (CRP) in patients treated with mild hypothermia after cardiac arrest, and to study their association to severe infections, post cardiac arrest syndrome (PCAS) and long-term outcome.

Methods

Serum samples from cardiac arrest patients treated with mild hypothermia were collected serially at admission, 2, 6, 12, 24, 36, 48 and 72 h after cardiac arrest. PCT and CRP concentrations were determined and tested for association with three definitions of infection, two surrogate markers of PCAS (circulation-SOFA and time to return of spontaneous circulation (ROSC)) and cerebral performance category (CPC) at six months.

Results

Eighty-four patients were included. PCT displayed an earlier release pattern than CRP with a significant increase within 2 h, increasing further at 6 h and onwards in patients with poor outcome. CRP increased later and continued to rise during the study period. PCT was strongly associated with circulation-SOFA and time to ROSC, and predicted a poor neurologic outcome with high accuracy (area under the receiver operating characteristic curve of 0.88, 0.86 and 0.87 at 12, 24 and 48 h respectively). No association of PCT or CRP to infection was observed.

Conclusion

Our results suggest that PCT is released early after resuscitation following cardiac arrest, is associated with markers of PCAS but not with infection, and is an accurate predictor of poor outcome. Validation of these findings in larger studies is warranted.     

Blood ammonia is a predictive biomarker of neurologic outcome in cardiac arrest patients treated with therapeutic hypothermia

Purpose

The aim of this study was to investigate the value of commonly examined laboratory measurements, including ammonia and lactate, in predicting neurologic outcome of out-of-hospital cardiac arrest (OHCA) patients treated with therapeutic hypothermia (TH).

Methods

This was a retrospective cohort study of patients with a return of spontaneous circulation after OHCA who were treated with TH between February 2007 and July 2010. We measured typical blood measurements on arrival at the emergency department. The subjects were classified into 2 groups: the good neurologic outcome group (Cerebral Performance Category [CPC] 1-2 at 1 month) and the poor neurologic outcome group (Cerebral Performance Category 3-5). We compared blood biomarker levels and basal characteristics between the 2 groups. Logistic regression analyses were performed to determine independent biomarkers that predict poor neurologic outcome.

Results

A total of 117 patients were included. Between the 2 groups, significantly different levels of blood measurements included hemoglobin level, pH, Pao₂, Paco₂, base excess, albumin, glucose, potassium, chloride, bilirubin, phosphorous, and ammonia. In multivariate analyses, blood ammonia level (>96 mg/dL; odds ratio [OR], 7.240; 95% confidence interval [CI], 1.718-30.512), noncardiac causes (OR, 46.215; 95% CI, 9.670-220.873), and time interval from collapse to return of spontaneous circulation (>33 min; OR, 5.943; 95% CI, 1.543-22.886) were significantly related to poor neurologic outcome.

Conclusion

Among the blood measurements on emergency department arrival, blood ammonia (>96 mg/dL) was the only independent predictive biomarker of poor neurologic outcome. Thus, higher blood ammonia level was associated with poor neurologic outcome in OHCA patients treated with TH.