Repeated diffusion weighted imaging in comatose cardiac arrest patients with therapeutic hypothermia

BackgroundThe aim of this study was to evaluate the changing pattern and prognostic values of diffusion-weighted imaging (DWI) at two time points in cardiac arrest patients treated with therapeutic hypothermia.MethodsTwenty two patients with cardiac arrest who underwent two DWI studies were enrolled in the retrospective study. The first DWI was performed after the induction of therapeutic hypothermia (median 6.0 h) and was repeated between 48 h and 168 h (second DWI, median 74 h). Apparent diffusion coefficient (ADC) values were measured in the predefined brain regions, and qualitative analysis was also performed. Good neurologic outcomes were defined as Cerebral Performance Category (CPC) scores of 1 and 2.ResultsThe ADC value tended to increase over time except the cortical regions of the poor outcome group (N = 10). In the comparisons of receiver operating characteristic (ROC) curve to predict poor outcome using ADC value, postcentral cortex in the second DWI has a better association with neurological outcome (p = 0.001, area under the curve (AUC) = 0.996 for second DWI, AUC = 0.571 for first DWI). In the same analysis using qualitative score, precentral cortex, postcentral cortex, parietal lobe, occipital lobe, caudate and putamen in the second DWI have a better association with neurological outcome.ConclusionsThe changing pattern of ADC values after cardiac arrest is different according to anatomic region and neurologic status. The DWI after 48 h has a better association with neurological outcome of cardiac arrest patients in both quantitative and qualitative analysis.     

Early goal-directed hemodynamic optimization combined with therapeutic hypothermia in comatose survivors of out-of-hospital cardiac arrest

BackgroundComatose survivors of out-of-hospital cardiac arrest (OHCA) have high in-hospital mortality due to a complex pathophysiology that includes cardiovascular dysfunction, inflammation, coagulopathy, brain injury and persistence of the precipitating pathology. Therapeutic hypothermia (TH) is the only intervention that has been shown to improve outcomes in this patient population. Due to the similarities between the post-cardiac arrest state and severe sepsis, it has been postulated that early goal-directed hemodyamic optimization (EGDHO) combined with TH would improve outcome of comatose cardiac arrest survivors.ObjectiveWe examined the feasibility of establishing an integrated post-cardiac arrest resuscitation (PCAR) algorithm combining TH and EGDHO within 6 h of emergency department (ED) presentation.MethodsIn May, 2005 we began prospectively identifying comatose (Glasgow Motor Score < 6) survivors of OHCA treated with our PCAR protocol. The PCAR patients were compared to matched historic controls from a cardiac arrest database maintained at our institution.ResultsBetween May, 2005 and January, 2008, 18/20 (90%) eligible patients were enrolled in the PCAR protocol. They were compared to historic controls from 2001 to 2005, during which time 18 patients met inclusion criteria for the PCAR protocol. Mean time from initiation of TH to target temperature (33 °C) was 2.8 h (range 0.8–23.2; SD = h); 78% (14/18) had interventions based upon EGDHO parameters; 72% (13/18) of patients achieved their EGDHO goals within 6 h of return of spontaneous circulation (ROSC). Mortality for historic controls who qualified for the PCAR protocol was 78% (14/18); mortality for those treated with the PCAR protocol was 50% (9/18) (p = 0.15).ConclusionsIn patients with ROSC after OHCA, EGDHO and TH can be implemented simultaneously.     

History of diabetes mellitus as a neurologic predictor in comatose survivors of cardiac arrest of cardiac origin treated with mild hypothermia

AimTo investigate the impact of a history of diabetes mellitus on the neurologic outcome in comatose survivors of cardiac arrest of cardiac origin treated with mild hypothermia.MethodsA prospective observational study was performed between September 2003 and July 2008. Eighty comatose survivors of cardiac arrest of cardiac origin were treated with mild hypothermia. Neurologic outcome at the time of hospital discharge, 30-day survival, and complications were assessed.ResultsTwenty-four of the 80 patients (30%) had a history of diabetes. The rate of favorable neurologic outcome was significantly lower in diabetic (17%) than in nondiabetic patients (46%) (p = 0.01). The rate of 30-day survival was lower in diabetic (33%) than in nondiabetic patients (54%), but the difference was not significant (p = 0.10). Multivariate analysis suggested that a history of diabetes was an independent predictor of unfavorable neurologic outcome (odds ratio 7.00, 95% confidence interval 1.42–46.19, p = 0.03), but not for 30-day survival. There was no significant difference in the prevalence of complications.ConclusionA history of diabetes is associated with poor neurologic outcome in comatose survivors of cardiac arrest treated with mild hypothermia.     

Diffusion and perfusion MRI of the brain in comatose patients treated with mild hypothermia after cardiac arrest: A prospective observational study

BackgroundOutcome for resuscitated cardiac arrest (CA) patients is poor. The 1-year survival rate with favourable neurological outcome (CPC 1-2) after out-of-hospital CA is reported to be 4%. Among resuscitated patients treated within an ICU, approximately 50% regain consciousness, whereas the other 50% remain comatose before they die. Induced hypothermia significantly improves the neurological outcome and survival in patients with primary CA who remain comatose after return of spontaneous circulation.AimTo evaluate magnetic resonance imaging (MRI) changes in resuscitated CA patients remaining in coma after treatment with hypothermia.MethodsThis prospective, observational study comprised 20 resuscitated CA patients who remained in coma 3 days after being treated with mild hypothermia (32–34 °C during 24 h). Diffusion and perfusion MRI of the entire brain was performed approximately 5 days after CA. Autopsy was done on two patients.ResultsThe largest number of diffusion changes on MRI was found in the 16 patients who died. The parietal lobe showed the largest difference in number of acute ischaemic MRI lesions in deceased compared with surviving patients. Perfusion changes, ≥±2 SD compared with healthy volunteers from a previously published cerebral perfusion study, were found in seven out of eight patients. The autopsies showed lesions corresponding to the pathologic changes seen on MRI.ConclusionDiffusion and perfusion MRI are potentially helpful tools for the evaluation of ischaemic brain damage in resuscitated comatose patients treated with hypothermia after CA.     

Sinus bradycardia during hypothermia in comatose survivors of out-of-hospital cardiac arrest – A new early marker of favorable outcome?

BackgroundBradycardia is a common finding in patients undergoing therapeutic hypothermia (TH) following out-of-hospital cardiac arrest (OHCA), presumably as a normal physiological response to low body temperature. We hypothesized that a normal physiological response with sinus bradycardia (SB) indicates less neurological damage and therefore would be associated with lower mortality.MethodsWe studied 234 consecutive comatose survivors of OHCA with presumed cardiac etiology and shockable primary rhythm, who underwent a full 24-h TH-protocol (33 °C) at a tertiary heart center (years: 2004–2010). Primary endpoint was 180-day mortality; secondary endpoint was favorable neurological outcome (180-day cerebral performance category: 1–2).ResultsSB, defined as sinus rhythm <50 beats per minute during TH, was present in 115 (49%) patients. Baseline characteristics including sex, witnessed arrest, bystander cardiopulmonary resuscitation and time to return of spontaneous circulation were not different between SB- and no-SB patients. However, SB-patients were younger, 57 ± 14 vs. 63 ± 14 years, p < 0.001 and less frequently had known heart failure (7% vs. 20%, p < 0.01).Patients experiencing SB during the hypothermia phase of TH had a 17% 180-day mortality rate compared to 38% in no-SB patients (p < 0.001), corresponding to a 180-day hazard ratio (HR_adjusted = 0.45 (0.23–0.88, p = 0.02)) in the multivariable analysis. Similarly, SB during hypothermia was directly associated with lower odds of unfavorable neurological outcome (OR_unadjusted = 0.42 (0.23–0.75, p < 0.01).ConclusionSinus bradycardia during therapeutic hypothermia is independently associated with a lower 180-day mortality rate and may thus be a novel, early marker of favorable outcome in comatose survivors of OHCA.     

Outcomes of asphyxial cardiac arrest patients who were treated with therapeutic hypothermia: A multicentre retrospective cohort study

IntroductionWhile therapeutic hypothermia (TH) is in clinical use, its efficacy in certain patient groups is unclear. This study was designed to describe the characteristics and outcomes of patients with out-of-hospital cardiac-arrest (OHCA) caused by asphyxia, who were treated with TH.Patients and methodsA multicentre, retrospective, registry-based study was performed using data from the period 2007–2012. Comatose patients who were treated with TH after asphyxial cardiac arrest were included, while those who with cardiac arrest attributed to hanging, drowning or gas intoxication were excluded.ResultsOf a total of 932 OHCA patients in the registry, 111 were enrolled in this study. The mean age was 65.8 ± 16.3 years with individuals who were ≥65 years of age accounted for 61.3% of the cohort. Foreign-body airway obstruction was the most common cause (70.3%) of the cardiac arrest. Eighty patients (72.1%) presented with an initial non-shockable rhythm. In all institutions target TH temperatures were 32–34 °C, but TH maintenance times varied. A total of 52 patients (46.8%) survived, of whom six patients (5.4%) showed a good neurologic outcome (cerebral performance category scale 1–2). The pupil light reflex, corneal reflex and time to return of spontaneous circulation (p = 0.012, 0.015 and 0.032, respectively) were associated with survival. Witnessed arrest, age, previous lung disease, bystander basic life support and time factors were not associated with survival.ConclusionAbout half of patients who underwent TH after asphyxial cardiac arrest survived, but a very small number showed a good neurologic outcome. The TH maintenance times were not uniform in these patients. Additional research regarding both the appropriate TH guidelines for patients with asphyxial cardiac arrest and improvement of their neurologic outcome is needed.     

Bispectral index (BIS) helps predicting bad neurological outcome in comatose survivors after cardiac arrest and induced therapeutic hypothermia

Aim of the studyDetermine the use of bispectral index (BIS) as prognostic tool in therapeutic hypothermia (TH) treated comatose survivors after cardiac arrest (CA), regardless of initial rhythm, location or cause.MethodsProspective, single-centre, unblinded, observational cohort study in an 18 bed general ICU in a tertiary teaching hospital. 45 consecutive comatose patients admitted after CA and treated with TH were included. All patients were sedated with a standardised protocol including neuromuscular blockade. Induced TH was started as soon as possible after arrival in the hospital and continued for 24 h before slow rewarming. Sedation was stopped after reaching normothermia (36 °C). All patients benefited from maximal supportive intensive care and no therapeutic withdrawal or withholding was done unless bad neurological status was confirmed. Continuous BIS monitoring was performed over 72 h in all patients.Results14 patients presented BIS values of zero (0) during their ICU stay. At 6 months 11 patients were dead, 1 remained comatose and 2 had severe neurological sequelae (CPC3). No patient of this group had good neurological outcome or improved his neurological outcome between ICU and 6-month follow-up. 31 patients had BIS values higher than 0. At 6 months of those, 11 died, none remained comatose, 3 had bad neurological outcome (CPC3) and 17 had no or minor neurological sequelae (CPC1-2). Thus no correlation between good outcome and BIS values higher than 0 is possible.ConclusionsBIS values of 0 help predict bad neurological outcome after CA and induced hypothermia.     

Neurocognitive outcomes following successful resuscitation from cardiac arrest

IntroductionCardiac arrest commonly results in varying degrees of cognitive injury. Standard outcome measures used in the cardiac arrest cohort do not rigorously evaluate for these injury patterns. We examined the utility of the Computerized Assessment for Mild Cognitive Injury (CAMCI) in cardiac arrest (CA) survivors. We hypothesized that cognitive deficits would be more severe in patients who were comatose on hospital arrival.MethodsProspective cohort of CA survivors at a single tertiary care facility where participants received neurocognitive testing using CAMCI. CAMCI results were subdivided into memory, attention, and executive functions. Scores between subjects who were initially comatose and were not comatose following resuscitation were compared using the Mann–Whitney test.ResultsOf 72 subjects included, the majority (N = 44) were initially comatose following resuscitation with mean age of 54 (±14) years. The majority experienced a good neurologic outcome based on Cerebral Performance Category (N = 47; 66%) and Modified Rankin Scale (N = 38; 53%). Time from resuscitation to CAMCI testing was not associated with total CAMCI score in this cohort (Pearson's r² value −0.1941, p = 0.20). Initially comatose and not comatose subjects did not differ in their CAMCI overall scores (p = 0.33), or in any subtest areas. The not comatose cohort had 1 subtest for which there was a Moderate Risk for mild cognitive impairment (Nonverbal Accuracy), and 2 for which there was a Moderately Low Risk (Verbal Accuracy and Executive Accuracy). The Comatose cohort had 4 subtests, which were deemed Moderately Low Risk for cognitive impairment (Verbal Accuracy, Attention Accuracy, Executive Accuracy and Nonverbal Accuracy).ConclusionsIn-hospital CAMCI testing suggests memory, attention and executive impairment are commonly in patients following resuscitation from cardiac arrest. Outcome evaluations should test for deficits in memory, attention, and executive function.     

Characteristics and outcome of cardiopulmonary resuscitation in hospitalised African children

ObjectiveTo review the characteristics and outcome of cardiopulmonary resuscitation in children at a rural hospital in Kenya.Patients and methodAll children aged 0–14 years who experienced ≥1 episode of respiratory or cardiopulmonary arrest during April 2002–2004 were prospectively identified. Demographic variables, cause of hospitalisation, type and duration of arrest, resuscitation measures taken and outcomes were determined.Results114 children experienced at least one episode of respiratory arrest (RA) or cardiopulmonary arrest (CPA). Cardiopulmonary resuscitation (CPR) was performed on all children. “Do not resuscitate order” (DNR) was given in 15 patients after initial resuscitation. Eighty two patients (72%) had RA and 32 (28%) had CPA. 25/82 (30%) patients with RA survived initial CPR compared to 5/32 (16%) with CPA. Survival at discharge was 22% (18/82) in children who had RA while no one with CPA survived at discharge. The leading underlying diseases were severe malaria, septicaemia and severe malnutrition. Prolonged resuscitation beyond 15 min and receiving adrenaline [epinephrine] (at least one dose of 10 μg/kg IV) were predictive of poor final outcome.ConclusionCardiopulmonary arrest after admission has a very poor prognosis in our hospital. Infectious diseases are the main underlying causes of arrest. If a child fails to respond to the basic tenements of PALS within 15 min then it is unlikely that further efforts to sustain life will be fruitful in hospitals where ventilation facilities are not present.     

Prophylactic antibiotics are associated with a lower incidence of pneumonia in cardiac arrest survivors treated with targeted temperature management

IntroductionProphylactic antibiotics (PRO) reduce the incidence of early-onset pneumonia in comatose patients with structural brain injury, but have not been examined in cardiac arrest survivors undergoing targeted temperature management (TTM). We investigated the effect of PRO on the development of pneumonia in that population.MethodsWe conducted a retrospective cohort study comparing patients treated with PRO to those not receiving PRO (no-PRO) using Northern Hypothermia Network registry data. Cardiac arrest survivors ≥18 years of age with a GCS < 8 at hospital admission and treated with TTM at 32–34 °C were enrolled in the registry. Differences were analyzed in univariate analyses and with logistic regression models to evaluate independent associations of clinical factors with incidence of pneumonia and good functional outcome.Results416 of 1240 patients (33.5%) received PRO. Groups were similar in age, gender, arrest location, initial rhythm, and time from collapse to return of spontaneous circulation. PRO patients had less pneumonia (12.6% vs. 54.9%, p < 0.001) and less sepsis (1.2 vs. 5.7%, p < 0.001) compared to no-PRO patients. ICU length of stay (98 vs. 100 h, p = 0.2) and incidence of a good functional outcome (41.1 vs. 36.6%, p = 0.19) were similar between groups. Backwards stepwise logistic regression demonstrated PRO were independently associated with a lower incidence of pneumonia (OR 0.09, 95% 0.06–0.14, p < 0.001) and a similar incidence of good functional outcome.ConclusionsProphylactic antibiotics were associated with a reduced incidence of pneumonia but a similar rate of good functional outcome.     

Higher achieved mean arterial pressure during therapeutic hypothermia is not associated with neurologically intact survival following cardiac arrest

IntroductionTo determine if higher achieved mean arterial blood pressure (MAP) during treatment with therapeutic hypothermia (TH) is associated with neurologically intact survival following cardiac arrest.MethodsRetrospective analysis of a prospectively collected cohort of 188 consecutive patients treated with TH in the cardiovascular intensive care unit of an academic tertiary care hospital.ResultsNeurologically intact survival was observed in 73/188 (38.8%) patients at hospital discharge and in 48/162 (29.6%) patients at a median follow up interval of 3 months. Patients in shock at the time of admission had lower baseline MAP at the initiation of TH (81 versus 87 mmHg; p = 0.002), but had similar achieved MAP during TH (80.3 versus 83.7 mmHg; p = 0.11). Shock on admission was associated with poor survival (18% versus 52%; p < 0.001). Vasopressor use among all patients was common (84.6%) and was not associated with increased mortality. A multivariable analysis including age, initial rhythm, time to return of spontaneous circulation, baseline MAP and achieved MAP did not demonstrate a relationship between MAP achieved during TH and poor neurological outcome at hospital discharge (OR 1.28, 95% CI 0.40–4.06; p = 0.87) or at outpatient follow up (OR 1.09, 95% CI 0.32–3.75; p = 0.976).ConclusionWe did not observe a relationship between higher achieved MAP during TH and neurologically intact survival. However, shock at the time of admission was clearly associated with poor outcomes in our study population. These data do not support the use of vasopressors to artificially increase MAP in the absence of shock. There is a need for prospective, randomized trials to further define the optimum blood pressure target during treatment with TH.     

Early targeted brain COOLing in the cardiac CATHeterisation laboratory following cardiac arrest (COOLCATH)

IntroductionTrials demonstrate significant clinical benefit in patients receiving therapeutic hypothermia (TH) after cardiac arrest. However, incidence of mortality and morbidity remains high in this patient group. Rapid targeted brain hypothermia induction, together with prompt correction of the underlying cause may improve outcomes in these patients. This study investigates the efficacy of Rhinochill^®, an intranasal cooling device over Blanketrol^®, a surface cooling device in inducing TH in cardiac arrest patients within the cardiac catheter laboratory.Methods70 patients were randomized to TH induction with either Rhinochill^® or Blanketrol^®. Primary outcome measures were time to reach tympanic ≤34 °C from randomisation as a surrogate for brain temperature and oesophageal ≤34 °C from randomisation as a measurement of core body temperature. Secondary outcomes included first hour temperature drop, length of stay in intensive care unit, hospital stay, neurological recovery and all-cause mortality at hospital discharge.ResultsThere was no difference in time to reach ≤34 °C between Rhinochill^® and Blanketrol^® (Tympanic ≤34 °C, 75 vs. 107 mins; p = 0.101; Oesophageal ≤34 °C, 85 vs. 115 mins; p = 0.151). Tympanic temperature dropped significantly with Rhinochill^® in the first hour (1.75 vs. 0.94 °C; p < 0.001). No difference was detected in any other secondary outcome measures. Catheter laboratory-based TH induction resulted in a survival to hospital discharge of 67.1%.ConclusionIn this study, Rhinochill^® was not found to be more efficient than Blanketrol^® for TH induction, although there was a non-significant trend in favour of Rhinochill^® that potentially warrants further investigation with a larger trial.     

EEG reactivity to pain in comatose patients: Importance of the stimulus type

IntroductionElectroencephalogram (EEG) background reactivity is a potentially interesting outcome predictor in comatose patients, especially after cardiac arrest, but recent studies report only fair interrater reliability. Furthermore, there are no definite guidelines for its testing. We therefore investigated the EEG effect of standardized noxious stimuli in comatose patients not reactive to auditory stimuli.MethodsIn this prospective study we applied a protocol using three different painful stimuli (bilateral nipple pinching, pinprick at the nose base, finger-nail compression on each side), grouped in three distinct clusters with an alternated sequence, during EEG recordings in comatose patients. We only analyzed recordings showing any reactivity to pain. Fisher and χ² tests were used as needed to assess contingency tables.ResultsOf 42 studies, 12 did not show any background reactivity, 2 presented SIRPIDs, and 2 had massive artefacts; we thus analyzed 26 EEGs recorded in 17 patients (4 women, 24%). Nipple pinching more frequently induced a change in EEG background activity (p < 0.001), with a sensitivity of 97.4% for reactivity. Neither the order of the stimuli in the cluster (p = 0.723), nor the cluster order (p = 0.901) influenced the results.ConclusionIn this pilot study, bilateral, synchronous nipple pinching seems to be the most efficient method to test nociceptive EEG reactivity in comatose patients. This approach may enhance interrater reliability, but deserves confirmation in larger cohorts.     

Correlation between initial serum levels of lactate after return of spontaneous circulation and survival and neurological outcomes in patients who undergo therapeutic hypothermia after cardiac arrest

ObjectivesWe analysed the relationship between serum levels of lactate within 1 h of return of spontaneous circulation (ROSC) and survival and neurological outcomes in patients who underwent therapeutic hypothermia (TH).MethodsThis was a multi-centre retrospective and observational study that examined data from the first Korean Hypothermia Network (KORHN) registry from 2007 to 2012. The inclusion criteria were out-of-hospital cardiac arrest (OHCA) and examination of serum levels of lactate within 1 h after ROSC, taken from KORHN registry data. The primary endpoint was survival outcome at hospital discharge, and the secondary endpoint was poor neurological outcome (Cerebral Performance Category, CPC, 3–5) at hospital discharge. Initial lactate levels and other variables collected within 1 h of ROSC were analysed via multivariable logistic regression.ResultsData from 930 cardiac arrest patients who underwent TH were collected from the KORHN registry. In a total of 443 patients, serum levels of lactate were examined within 1 h of ROSC. In-hospital mortality was 289/443 (65.24%), and 347/443 (78.33%) of the patients had CPCs of 3–5 upon hospital discharge. The odds ratios of lactate levels for CPC and in-hospital mortality were 1.072 (95% confidence interval (CI) 1.026–1.121) and 1.087 (95% CI = 1.031–1.147), respectively, based on multivariate ordinal logistic regression analyses.ConclusionHigh levels of lactate in serum measured within 1 h of ROSC are associated with hospital mortality and high CPC scores in cardiac arrest patients treated with TH.     

Impact of intensified postresuscitation treatment on outcome of comatose survivors of out-of-hospital cardiac arrest according to initial rhythm

AimWe investigated the impact of intensified postresuscitation treatment in comatose survivors of out-of-hospital cardiac arrest (OHCA) of presumed cardiac etiology according to the initial rhythm at the emergency medical team arrival.MethodsInterventions and survival with Cerebral Performance Category (CPC) 1–2 within each group were retrospectively compared between the periods of conservative (1995–2003) and intensified (2004–2012) postresuscitation treatment.ResultsIn shockable group, therapeutic hypothermia (TH) increased from 1 to 93%, immediate invasive coronary strategy from 28 to 78%, intraaortic balloon pump from 4 to 21%, vasopressors/inotropes from 47 to 81% and antimicrobial agents from 65 to 86% during the intensified period as compared to conservative period (p < 0.001). This was associated with increased survival with CPC 1–2 from 27 to 47% (p < 0.001). After adjusting for age, sex and prehospital confounders, TH (OR = 2.12, 95% CI 1.25–3.61), percutaneous coronary intervention (OR 1.77, 95% CI 1.15–2.73) and antimicrobial agents (OR = 12.21, 95% CI 5.13–29.08) remained associated with survival with CPC 1–2. In non-shockable patients, TH also significantly increased from 1 to 74%, immediate invasive coronary strategy from 8 to 51%, intraaortic balloon pump from 2 to 9% and vasopressors/inotropes from 56 to 84% during intensified period without concomitant increase in survival with CPC 1–2 (7% vs. 9%; p = 0.27). After adjustment, only antimicrobial agents (OR = 8.43, 95% CI: 1.05–67.72) remained associated with survival with CPC 1–2.ConclusionIntensified postresuscitation treatment was associated with doubled survival in comatose survivors of OHCA with shockable rhythm. Such association could not be demonstrated in patients with non-shockable rhythm.     

Continuous electrodermal activity as a potential novel neurophysiological biomarker of prognosis after cardiac arrest – A pilot study

AimsNeurological outcome prognosis remains challenging in patients undergoing therapeutic hypothermia (TH) after cardiac resuscitation. Technological advances allow for a novel wrist-worn device to continuously record electrodermal activity (EDA), a measure of pure sympathetic activity.MethodsA prospective cohort study was performed to determine the yield of continuous EDA in patients treated with TH for coma after cardiac arrest during hypothermia and normothermia. Association between EDA parameters (event-related and nonspecific electrodermal responses (ER-EDR, NS-EDR)) and outcome measures (cerebral performance category [CPC]) (Full Outline in UnResponsivenss (FOUR) score) were assessed.ResultsEighteen patients were enrolled. Total number of EDR (66.4 vs 12.0/24 h, p = 0.02), ER-EDR (39.5 vs 11.2/24 h, p = 0.009), median amplitude change of all EDR (0.08 vs 0.03 μSI, p = 0.03) and ER-EDR (0.14 vs 0.05 μSI, p = 0.025) were higher in patients with favorable (CPC 1–2) versus poor outcome (CPC 3–5) during hypothermia. Greater differences in EDA parameters were observed during hypothermia than normothermia. The FOUR score was correlated to the number of all EDR and median amplitudes.ConclusionsContinuous EDA potentially opens a new avenue for autonomic function monitoring in neurocritically ill patients. It is feasible in the ICU setting, even during hypothermic states. As a measure of a complete neurophysiological circuit, it may be a novel neurophysiologic biomarker of outcome after cardiac resuscitation.     

Serum S-100B is superior to neuron-specific enolase as an early prognostic biomarker for neurological outcome following cardiopulmonary resuscitation

IntroductionMost patients with cardiac arrest (CA) admitted to hospitals after successful cardiopulmonary resuscitation (CPR) are discharged with various degree of neurological deficits. To determine predictor of neurological outcome early and accurately, and to determine cutoff values, serum levels of protein S-100B and neuron-specific enolase (NSE) within 24 h after CA were assessed.Methods and resultsA multicenter prospective observational study was conducted between May 2007 and April 2008 at three medical institutions in Japan on 107 consecutive non-traumatic CA patients with return of spontaneous circulation after CPR. Based on “best-ever achieved” Glasgow-Pittsburgh cerebral performance categories (CPC) score within 6 months after CA, patients were classified into a “poor neurological outcome” group (CPC3 to CPC5) (n = 67) and “favorable neurological outcome” group (CPC1 and CPC2) (n = 13). Blood was sampled on admission, at 6 and 24 h after CA. Serum S-100B and NSE in “poor outcome” group were higher than those in “favorable outcome” group (P < 0.01). On ROC analysis, area under the curve of S-100B was 0.85, 0.94 and 1.0, respectively. These were greater than those of NSE at all sampling points. The “100%-specific” cutoff values of S-100B predictive of poor neurological outcome were 1.41, 0.21, and 0.05 ng/mL, respectively. These values corresponded to sensitivities of 20.9%, 62.8%, and 100%, respectively, each of which was higher than those of NSE.ConclusionsS-100B is more reliable as an early predictor of poor neurological outcome within 24 h after CA than NSE and can be applied clinically.     

The influence of rewarming after therapeutic hypothermia on outcome after cardiac arrest

IntroductionTreatment with hypothermia has been shown to improve outcome after cardiac arrest (CA). Current consensus is to rewarm at 0.25–0.5 °C/h and avoid fever. The aim of this study was to investigate whether active rewarming, the rate of rewarming or development of fever after treatment with hypothermia after CA was correlated with poor outcome.MethodsThis retrospective cohort study included adult patients treated with hypothermia after CA and admitted to the intensive care unit between January 2006 and January 2009. The average rewarming rate from end of hypothermia treatment (passive rewarming) or start active rewarming until 36 °C was dichotomized in a high (≥0.5 °C/h) or normal rate (<0.5 °C/h). Fever was defined as > 38 °C within 72 h after admission. Poor outcome was defined as death, vegetative state, or severe disability after 6 months.ResultsFrom 128 included patients, 56% had a poor outcome. Actively rewarmed patients (38%) had a higher risk for poor outcome, OR 2.14 (1.01–4.57), p < 0.05. However, this effect disappeared after adjustment for the confounders age and initial rhythm, OR 1.51 (0.64–3.58). A poor outcome was found in 15/21 patients (71%) with a high rewarming rate, compared to 54/103 patients (52%) with a normal rewarming rate, OR 2.61 (0.88–7.73), p = 0.08. Fever was not associated with outcome, OR 0.64 (0.31–1.30), p = 0.22.ConclusionsThis study showed that patients who needed active rewarming after therapeutic hypothermia after CA did not have a higher risk for a poor outcome. In addition, neither speed of rewarming, nor development of fever had an effect on outcome.     

Initial end-tidal carbon dioxide as a prognostic indicator for inpatient PEA arrest

AimInvestigate the relationship of initial PetCO2 values of patients during inpatient pulseless electrical activity (PEA) cardiopulmonary arrest with return of spontaneous circulation (ROSC) and survival to discharge.MethodsThis study was performed in two urban, academic inpatient hospitals. Patients were enrolled from July 2009 to July 2013. A comprehensive database of all inpatient resuscitative events is maintained at these institutions, including demographic, clinical, and outcomes data. Arrests are stratified by primary etiology of arrest using a priori criteria. Inpatients with PEA arrest for whom recorded PetCO2 was available were included in the analysis. Capnography data obtained after ROSC and/or more than 10 min after initiation of CPR were excluded. Multivariable logistic regression was used to explore the association between initial PetCO2 >20 mmHg and both ROSC and survival-to-discharge.ResultsA total of 50 patients with PEA arrest and pre-ROSC capnography were analyzed. CPR continued an average of 11.8 min after initial PetCO2 was recorded confirming absence of ROSC at time of measurement. Initial PetCO2 was higher in patients with versus without eventual ROSC (25.3 ± 14.4 mmHg versus 13.4 ± 6.9 mmHg, P = 0.003). After adjusting for age, gender, and arrest location (ICU versus non-ICU), initial PetCO2 >20 mmHg was associated with increased likelihood of ROSC (adjusted OR 4.8, 95% CI 1.2–19.2, P = 0.028). Initial PetCO2 was not significantly associated with survival-to-discharge (P = 0.251).ConclusionsInitial PetCO2 >20 mmHg during CPR was associated with ROSC but not survival-to-discharge among inpatient PEA arrest victims. This analysis is limited by relatively small sample size.     

A randomised, double-blind, multi-centre trial comparing vasopressin and adrenaline in patients with cardiac arrest presenting to or in the Emergency Department

ObjectiveTo compare vasopressin and adrenaline in the treatment of patients with cardiac arrest presenting to or in the Emergency Department (ED).DesignA randomised, double-blind, multi-centre, parallel-design clinical trial in four adult hospitals.MethodEligible cardiac arrest patients (confirmed by the absence of pulse, unresponsiveness and apnea) aged >16 (aged > 21 for one hospital) were randomly assigned to intravenous adrenaline (1 mg) or vasopressin (40 IU) at ED. Patients with traumatic cardiac arrest or contraindication for cardiopulmonary resuscitation (CPR) were excluded. Patients received additional open label doses of adrenaline as per current guidelines. Primary outcome was survival to hospital discharge (defined as participant discharged alive or survival to 30 days post-arrest).Main resultsThe study recruited 727 participants (adrenaline = 353; vasopressin = 374). Baseline characteristics of the two groups were comparable. Eight participants (2.3%) from adrenaline and 11 (2.9%) from vasopressin group survived to hospital discharge with no significant difference between groups (p = 0.27, RR = 1.72, 95% CI = 0.65–4.51). After adjustment for race, medical history, bystander CPR and prior adrenaline given, more participants survived to hospital admission with vasopressin (22.2%) than with adrenaline (16.7%) (p = 0.05, RR = 1.43, 95% CI = 1.02–2.04). Sub-group analysis suggested improved outcomes for vasopressin in participants with prolonged arrest times.ConclusionsCombination of vasopressin and adrenaline did not improve long term survival but seemed to improve survival to admission in patients with prolonged cardiac arrest. Further studies on the effect of vasopressin combined with therapeutic hypothermia on patients with prolonged cardiac arrest are needed.