Amplitude-integrated EEG (aEEG) predicts outcome after cardiac arrest and induced hypothermia

Objective To evaluate the use of continuous amplitude-integrated EEG (aEEG) as a prognostic tool for survival and neurological outcome in cardiac arrest patients treated with hypothermia.Design Prospective, observational study.Setting Multidisciplinary intensive care unit in a university hospital.Intervention Comatose survivors of cardiac arrest were treated with induced hypothermia for 24 h. An aEEG recording was initiated upon arrival at the ICU and continued until the patient regained consciousness or, if the patient remained in coma, no longer than 120 h. The aEEG recording was not available to the ICU physician, and the aEEG tracings were interpreted by a neurophysiologist with no knowledge of the patient's clinical status. Only clinically visible seizures were treated. Measurements and results Thirty-four consecutive hypothermia-treated cardiac arrest survivors were included. At normothermia (mean 37 h after cardiac arrest), the aEEG pattern was discriminative for outcome. All 20 patients with a continuous aEEG at this time regained consciousness, whereas 14 patients with pathological aEEG patterns (flat, suppression-burst or status epilepticus) did not regain consciousness and died in hospital. Patients were evaluated neurologically upon discharge from the ICU and after 6 months, using the Cerebral Performance Category (CPC) scale. Eighteen patients were alive with a good cerebral outcome (CPC 1--2) at 6-month follow-up. Conclusion A continuous aEEG pattern at the time of normothermia was discriminative for regaining consciousness. aEEG is an easily applied method in the ICU setting.     

心搏骤停后昏迷患者神经功能预后评估的研究进展

心肺复苏后昏迷患者早期神经功能预后评估作为心搏骤停(CA)后管理的重要组成部分,具有显著的临床意义.本文从神经系统检查、脑电图、诱发电位、神经影像学及血清生物标志物等方面,结合亚低温治疗对神经功能评估的影响,综述了CA后昏迷患者神经功能预后评估的研究进展.     

Therapeutic hypothermia after cardiac arrest: A retrospective comparison of surface and endovascular cooling techniques

Objectives

Therapeutic hypothermia (32-34 °C) is recommended for comatose survivors of cardiac arrest; however, the optimal technique for cooling is unknown. We aimed to compare therapeutic hypothermia using either surface or endovascular techniques in terms of efficacy, complications and outcome.

Design

Retrospective cohort study.

Setting

Thirty-bed teaching hospital intensive care unit (ICU).

Patients

All patients (n = 83) undergoing therapeutic hypothermia following cardiac arrest over a 2.5-year period. The mean age was 61 ± 16 years; 88% of arrests occurred out of hospital, and 64% were ventricular fibrillation/tachycardia.

Interventions

Therapeutic hypothermia was initiated in the ICU using iced Hartmann's solution, followed by either surface (n = 41) or endovascular (n = 42) cooling; choice of technique was based upon endovascular device availability. The target temperature was 32-34 °C for 12-24 h, followed by rewarming at a rate of 0.25 °C h⁻¹.

Measurements and main results

Endovascular cooling provided a longer time within the target temperature range (p = 0.02), less temperature fluctuation (p = 0.003), better control during rewarming (0.04), and a lower 48-h temperature load (p = 0.008). Endovascular cooling also produced less cooling-associated complications in terms of both overcooling (p = 0.05) and failure to reach the target temperature (p = 0.04). After adjustment for known confounders, there were no differences in outcome between the groups in terms of ICU or hospital mortality, ventilator free days and neurological outcome.

Conclusion

Endovascular cooling provides better temperature management than surface cooling, as well as a more favorable complication profile. The equivalence in outcome suggested by this small study requires confirmation in a randomized trial.     

Empirical hospital and professional charges for patient care associated with out of hospital cardiac arrest before and after implementation of therapeutic hypothermia for comatose survivors

Objective

The objectives of this study are to characterize the total hospital and professional charges for patients with out of hospital cardiac arrest both with and without therapeutic hypothermia treatment.

Methods

Retrospective cohort study of all adult patients with non-traumatic out of hospital cardiac arrest brought to the ED of a single tertiary care hospital over 20 months preceding and 20 months following implementation of therapeutic hypothermia for comatose survivors. Billing and clinical data were obtained from administrative databases and the electronic medical record using explicit audited abstraction. Demographic, payer characteristics, median charges and reimbursements with interquartile ranges are described before and after implementation, stratified by patient outcome.

Results

Two hundred and twenty-three patients met study criteria. The median charge was $3,112 among the 135 patients (60.5%) that did not survive to admission and $94,916 among the 88 (39.5%) that did. Median charges before and after implementation of therapeutic hypothermia were $6,324 and $15,537 respectively. Medicare was the most frequent payer. Good neurological outcome occurred in 11/115 patients (9.6%) prior to implementation and 22/108 patients (20.4%) after. Among 23 patients treated with hypothermia, good neurological outcome occurred in 11 patients (47.8%). Good neurological outcome and treatment with hypothermia were associated with increased procedure utilization and higher charges.

Conclusion

Empirical patient level data confirm that charges for patients with out of hospital cardiac arrest are substantial, even among patients that do not survive to hospital admission. Treatment with therapeutic hypothermia is associated with better outcomes, more procedures, and higher charges.     

Efficacy of diffusion-weighted magnetic resonance imaging performed before therapeutic hypothermia in predicting clinical outcome in comatose cardiopulmonary arrest survivors

Aim of the studyTo develop a clinically relevant and qualitative brain magnetic resonance imaging (MRI) scoring system for acute stage comatose cardiac arrest patients.MethodsConsecutive comatose post-cardiopulmonary arrest patients were prospectively enrolled. Routine brain MRI sequences were scored by two independent and blinded experts. Predefined brain regions were qualitatively scored on diffusion-weighted imaging (DWI) sequences according to the severity of the abnormality on a scale from 0 to 4. The mean score provided by the raters determined poor outcome defined under the Cerebral Performance Categories 3, 4, or 5. DWI scans were repeated after therapeutic hypothermia (TH). The same qualitative scoring system was applied and results were compared to the initial scores.ResultsOut of 24 recruited patients, 19 with brain MRI scans were included. Of the 19 included patients, seven showed a good outcome at hospital discharge and 12 patients showed poor neurologic outcome. Median time from the arrest to the initial DWI was 166 min (IQR 114–240 min). At 100% specificity, the overall, cortex, and cortex plus deep grey nuclei scores predicted poor patient outcome with a sensitivity of 91.7–100% (95% CI). Follow-up DWI scans after TH showed worse results than initial scans.ConclusionA qualitative MRI scoring system effectively assessed the severity of hypoxic-ischaemic brain injury following cardiopulmonary arrest. The scoring system may provide useful prognostic information in comatose cardiopulmonary arrest patients.     

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.     

Combining brain computed tomography and serum neuron specific enolase improves the prognostic performance compared to either alone in comatose cardiac arrest survivors treated with therapeutic hypothermia

Aim of the study

We determined whether combining the grey-to-white matter ratio (GWR) on brain computed tomography (CT) and serum neuron specific enolase (NSE) improves the prognostic performance when compared to either alone in cardiac arrest patients treated with therapeutic hypothermia (TH).

Methods

We performed a retrospective study of a cohort of cardiac arrest patients treated with TH. The Hounsfield unit was measured in the caudate nucleus (CN), putamen (P), posterior limb of internal capsule (PIC) and corpus callosum (CC); GWR was calculated as CN/PIC and P/CC. The NSE value was obtained at 0, 24, and 48 h after restoration of spontaneous circulation (ROSC). We analysed the prognostic performance of GWR and NSE, singly and in combination, in predicting poor neurologic outcome (cerebral performance category 3–5).

Results

Of the 224 included patients, 82 showed good neurologic outcome at hospital discharge, while 142 showed poor neurologic outcome. The P/CC (area under receiver operating characteristics (AUROC) 0.864, sensitivity/specificity 52.9%/100%) showed better prognostic performance than did the CN/PIC (AUROC 0.721, sensitivity/specificity 19.8%/100%). The NSE value at 48 h after ROSC (AUROC 0.895, sensitivity/specificity 60.2%/100%) showed the highest prognostic value among the three NSE time points. Analysis of 119 patients undergoing both brain CT and NSE at 48 h indicated that combining P/CC and NSE improved the sensitivity (78.6%) compared to either alone (48.6%, 62.9%).

Conclusion

Combining brain CT and serum NSE improves the prognostic performance when compared to either alone in predicting poor neurologic outcome in cardiac arrest patients treated with TH.     

Clinical examination for prognostication in comatose cardiac arrest patients

Objective

To build new algorithms for prognostication of comatose cardiac arrest patients using clinical examination, and investigate whether therapeutic hypothermia influences the value of the clinical examination.

Methods

From 2000 to 2007, 500 consecutive patients in non-traumatic coma were prospectively enrolled, 200 of whom were post-cardiac arrest. Outcome was determined by modified Rankin Scale (mRS) score at 6 months, with mRS ≤ 3 indicating good outcome. The clinical examination was performed on days 0, 1, 3 and 7 post-arrest, and clinical variables analyzed for importance in prognostication of outcome. A classification and regression tree analysis (CART) was used to develop a predictive algorithm.

Results

Good outcome was achieved in 9.9% of patients. In CART analysis, motor response was often chosen as a root node, and spontaneous eye movements, pupillary reflexes, eye opening and corneal reflexes were often chosen as splitting nodes. Over 8% of patients with absent or extensor motor response on day 3 achieved a good outcome, as did 2 patients with myoclonic status epilepticus. The odds of achieving a good outcome were lower in patients who suffered asystole (OR 0.187, 95% CI: 0.039–0.875, p = 0.033) compared with ventricular fibrillation or non-perfusing ventricular tachycardia, but some still achieved good outcome. The absence of pupillary and corneal reflexes on day 3 remained highly reliable for predicting poor outcome, regardless of therapeutic hypothermia utilization.

Conclusion

The clinical examination remains central to prognostication in comatose cardiac arrest patients in the modern area. Future studies should incorporate the clinical examination along with modern technology for accurate prognostication.     

Public health impact of full implementation of therapeutic hypothermia after cardiac arrest

AIM: Induced hypothermia improves outcomes in patients resuscitated successfully after cardiac arrest due to ventricular fibrillation. However, a minority of US physicians currently use the therapy. The aim of this study was to project the public health impact of implementing hypothermia in all eligible US out-of-hospital cardiac arrest (OHCA) survivors. METHODS: The number of OHCA patients expected to have a good outcome after hypothermia was calculated using a linear model. Literature-derived input variables included OHCA incidence rates and US 2000 census data, percent with return to spontaneous circulation (ROSC), percent eligible for hypothermia, and the expected benefit from hypothermia. Sensitivity analyses were performed to calculate a plausible range around the reference case. RESULTS: An additional 2298 US patients per year are expected to have a good neurological outcome if US physicians implement hypothermia fully in comatose survivors of OHCA. The two-way sensitivity analyses found that this number ranged from 766 to 5171 patients. This model is similarly sensitive to varying the incidence of OHCA, percent with ROSC, percent of patients eligible for hypothermia, and the number needed to treat. CONCLUSIONS: If US physicians adopt therapeutic hypothermia fully in eligible patients with OHCA, 2298 additional patients per year would be expected to achieve a good neurological outcome, a substantial public health impact. Barriers to adoption should be researched and addressed to increase acceptance and use by US physicians.     

温州地区开展亚低温治疗对心肺复苏后昏迷患者预后影响的研究

目的探讨温州地区推广亚低温治疗（HT）对心肺复苏（CPR）后昏迷患者预后的影响。 方法温州地区成立1家推广示范基地及10家推广基地,自2014年1月至2016年12月,对CPR后昏迷患者实施HT。记录所有患者亚低温治疗相关信息,比较推广期间3年患者ICU出院存活率、神经功能恢复良好率及严重致残率。 结果推广期间共对133例CPR后昏迷患者实施HT,推广第1年、第2年、第3年分别为28、46、59例。推广第1年、第2年、第3年达到目标体温时间[8.0（3.0,18.8）、10.0（4.8,20.0）、6.0（2.0,12.0）h]、药物使用率[17（60.7%）、43（93.5%）、42（71.2%）]及肌松剂使用率[0（0%）、1（2.2%）、13（22.0%）]比较,差异均有统计学意义（H = 10.475,P = 0.005;χ² = 12.250,P = 0.002;χ² = 17.647,P < 0.001）。推广期间ICU出院存活率呈现逐年上升趋势,严重致残率呈现逐年下降趋势;但3年间比较差异均无统计学意义（χ² = 2.537,P = 0.281;χ² = 0.308,P = 0.857）。推广3年间神经功能恢复良好率比较,差异有统计学意义（χ² = 12.232,P =0.002）,且推广第3年较第1年及第2年神经功能恢复良好率更高[16（27.1%）、1（3.6%）、3（6.5%）,P均< 0.017]。 结论规范化的HT能有效地促进神经功能恢复。     

The pituitary-adrenal axis is activated more in non-survivors than in survivors of cardiac arrest, irrespective of therapeutic hypothermia

OBJECTIVE: To investigate the effect of therapeutic hypothermia in the prognostic value of the pituitary-adrenal axis in comatose patients after cardiac arrest. DESIGN: Prospective observational study in intensive care units (ICU) of a university and an affiliated regional hospital. PATIENTS: Twenty-nine consecutive patients, in coma after cardiac arrest, admitted to the ICU and treated by hypothermia. MEASUREMENTS: On ICU-admission (T=1), at reaching the target of 32-33 degrees C during therapeutic hypothermia (T=2), at the end of hypothermia (T=3) and 48h later (T=4), plasma adrenocorticotrophic hormone (ACTH), serum cortisol, albumin and corticosteroid-binding globulin (CBG) were measured. A short 250mug ACTH test was performed at each time-point, except at T=1. The free cortisol index (FCI) and free cortisol calculated by Coolens method were also evaluated. RESULTS: The ICU mortality was 59%, including withdrawal of life-sustaining treatment in 45% because of negative somatosensory evoked potentials. ACTH and (free) cortisol levels (mean 13.1pmol/L vs. 6.0pmol/L and 1250nmol/L vs. 596nmol/L, respectively) were higher in non-survivors than in survivors. Levels decreased in time, but the relative difference between outcome groups was maintained until T=4. The cortisol response to ACTH was lower in non-survivors at T=3 (P=0.047) only. CONCLUSIONS: In comatose patients resuscitated from cardiac arrest, the pituitary-adrenal axis is activated particularly in those dying in the ICU, irrespective of therapeutic hypothermia. Hence, activation of the axis may be a marker of fatal cerebral damage. There is no firm evidence for relative adrenal insufficiency associated with death and a transiently blunted cortisol response to ACTH in non-survivors may be attributed to higher baseline values.     

Therapeutic hypothermia is associated with improved neurologic outcome and survival in cardiac arrest survivors of non-shockable rhythms

Background

Therapeutic hypothermia improves neurologic outcomes in patients resuscitated from cardiac arrest due to ventricular fibrillation. However, its role in patients with cardiac arrest due to non-shockable rhythms (pulseless electrical activity (PEA) and asystole) is unclear. We hypothesized that therapeutic hypothermia favorably impacts neurologic outcome and survival in patients resuscitated from cardiac arrest due to non-shockable rhythms.

Methods

Retrospectively collected data on consecutive adult patients admitted to Hartford Hospital from 1/1/2004 to 11/1/2010 who survived a cardiac arrest due to PEA or asystole were analyzed. Patients who underwent therapeutic hypothermia (1/1/2007-11/1/2010) formed the hypothermia group while patients admitted prior to the institution of therapeutic hypothermia (1/1/2004-1/1/2007) at Hartford Hospital formed the control group. The primary end-point was measured using the Pittsburgh cerebral performance category (CPC) scale and patients were assessed for a good (CPC 1 and 2) or poor (CPC 3-5) neurological outcome prior to discharge from hospital. A secondary end-point was measured as survival at discharge from hospital.

Results

Of 100 post-cardiac arrest patients included in the study, 15/52 (29%) patients in the hypothermia group had a good neurologic outcome as compared to 5/43 (10%) patients in the control group (P = 0.021). On multivariate analysis, the odds ratio for good neurologic outcome and survival at discharge from the hospital with therapeutic hypothermia as compared to control were 4.35 (95% CI 1.10-17.24, P = 0.04) and 5.65 (CI 1.66-19.23, P = 0.006) respectively.

Conclusion

Therapeutic hypothermia is associated with favorable neurologic outcome and survival in patients resuscitated after cardiac arrest due to non-shockable rhythms.     

Prognostic factors associated with hospital survival in comatose survivors of cardiac arrest

AIM: To identify patient, cardiac arrest and management factors associated with hospital survival in comatose survivors of cardiac arrest.METHODS: A retrospective, single centre study of comatose patients admitted to our intensive care unit (ICU) following cardiac arrest during the twenty year period between 1993 and 2012. This study was deemed by the Human Research Ethics Committee (HREC) of Monash Health to be a quality assurance exercise, and thus did not require submission to the Monash Health HREC (Research Project Application, No. 13290Q). The study population included all patients admitted to our ICU between 1993 and 2012, with a discharge diagnosis including “cardiac arrest”. Patients were excluded if they did not have a cardiac arrest prior to ICU admission (i.e., if their primary arrest was during their admission to ICU), or were not comatose on arrival to ICU. Our primary outcome measure was survival to hospital discharge. Secondary outcome measures were ICU and hospital length of stay (LOS), and factors associated with survival to hospital discharge.RESULTS: Five hundred and eighty-two comatose patients were admitted to our ICU following cardiac arrest, with 35% surviving to hospital discharge. The median ICU and hospital LOS was 3 and 5 d respectively. There was no survival difference between in-hospital and out-of-hospital cardiac arrests. Males made up 62% of our cardiac arrest population, were more likely to have a shockable rhythm (56% vs 37%, P < 0.001), and were more likely to survive to hospital discharge (40% vs 28%, P = 0.006). On univariate analysis, therapeutic hypothermia, regardless of method used (e.g., rapid infusion of ice cold fluids, topical ice, “Arctic Sun”, passive rewarming, “Bair Hugger”) and location initiated (e.g., pre-hospital, emergency department, intensive care) was associated with increased survival. There was however no difference in survival associated with target temperature, time at target temperature, location of initial cooling, method of initiating cooling, method of maintaining cooling or method of rewarming. Patients that survived were more likely to have a shockable rhythm (P < 0.001), shorter time to return of spontaneous circulation (P < 0.001), receive therapeutic hypothermia (P = 0.03), be of male gender (P = 0.006) and have a lower APACHE II score (P < 0.001). After multivariate analysis, only a shockable initial rhythm (OR = 6.4, 95%CI: 3.95-10.4; P < 0.01) and a shorter time to return of spontaneous circulation (OR = 0.95, 95%CI: 0.93-0.97; P < 0.01) was found to be independently associated with survival to hospital discharge.CONCLUSION: In comatose survivors of cardiac arrest, shockable rhythm and shorter time to return of spontaneous circulation were independently associated with increased survival to hospital discharge.     

Cold saline infusion and ice packs alone are effective in inducing and maintaining therapeutic hypothermia after cardiac arrest

Aim of the study

Hypothermia treatment with cold intravenous infusion and ice packs after cardiac arrest has been described and used in clinical practice. We hypothesised that with this method a target temperature of 32-34 °C could be achieved and maintained during treatment and that rewarming could be controlled.

Materials and methods

Thirty-eight patients treated with hypothermia after cardiac arrest were included in this prospective observational study. The patients were cooled with 4 °C intravenous saline infusion combined with ice packs applied in the groins, axillae, and along the neck. Hypothermia treatment was maintained for 26 h after cardiac arrest. It was estimated that passive rewarming would occur over a period of 8 h. Body temperature was monitored continuously and recorded every 15 min up to 44 h after cardiac arrest.

Results

All patients reached the target temperature interval of 32-34 °C within 279 ± 185 min from cardiac arrest and 216 ± 177 min from induction of cooling. In nine patients the temperature dropped to below 32 °C during a period of 15 min up to 2.5 h, with the lowest (nadir) temperature of 31.3 °C in one of the patients. The target temperature was maintained by periodically applying ice packs on the patients. Passive rewarming started 26 h after cardiac arrest and continued for 8 ± 3 h. Rebound hyperthermia (>38 °C) occurred in eight patients 44 h after cardiac arrest.

Conclusions

Intravenous cold saline infusion combined with ice packs is effective in inducing and maintaining therapeutic hypothermia, with good temperature control even during rewarming.     

Prognostic value of electrographic postanoxic status epilepticus in comatose cardiac-arrest survivors in the therapeutic hypothermia era

Background

The independent prognostic significance of postanoxic status epilepticus (PSE) has not been evaluated prospectively since the introduction of therapeutic hypothermia. We studied 1-year functional outcomes and their determinants in comatose survivors of cardiac arrest (CA), with special attention to PSE.

Methods

106 comatose CA survivors admitted to the intensive care unit in 2005–2010 were included in a prospective observational study. The main outcome measure was a Cerebral Performance Category scale (CPC) of 1 or 2 (favorable outcome) 1 year after CA.

Results

CA occurred out-of-hospital in 89 (84%) patients and was witnessed from onset in 94 (89%). Median times were 6 min (IQR, 0–11) from CA to first-responder arrival and 23 min (14–40) from collapse to return of spontaneous circulation. PSE was diagnosed in 33 (31%) patients at a median of 39 h (4–49) after CA. PSE was refractory in 24 (22%) cases and malignant in 19 (20%). After 1 year, 31 (29.3%) patients had favorable outcomes including 2 (6.44%) with PSE. Factors independently associated with poor outcome (CPC ≥ 3) were PSE (odds ratio [OR], 14.28; 95% confidence interval [95% CI], 2.77–50.0; P = 0.001), time to restoration of spontaneous circulation (OR, 1.04/min; 95% CI, 1–1.07; P = 0.035), and LOD score on day 1 (OR, 1.28/point; 95% CI, 1.08–1.54; P = 0.003).

Conclusion

PSE strongly and independently predicts a poor outcome in comatose CA survivors receiving therapeutic hypothermia, but some patients with PSE survive with good functional outcomes. PSE alone is not sufficient to predict failure to awaken after CA in the era of therapeutic hypothermia.     

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.     

Predictors of poor neurologic outcome in patients after cardiac arrest treated with hypothermia: a retrospective study

Introduction

Outcome studies in patients with anoxic-ischemic encephalopathy focus on the early and reliable prediction of an outcome no better than a vegetative state or severe disability. We determined the effect of mild therapeutic hypothermia on the validity of the currently used clinical practice parameters.

Methods

We conducted a retrospective cohort study of adult comatose patients after cardiac arrest treated with hypothermia. All data were collected from medical charts and laboratory files and analyzed from the day of admission to the intensive care unit until day 7, discharge from the intensive care unit or death using the Utstein definitions for the registration of the data.

Results

We analyzed the data of 103 patients. The combination of an M1 or M2 on the Glasgow Coma Scale or absent pupillary reactions or absent corneal reflexes on day 3 was present in 80.6% of patients with an unfavourable and 11.1% of patients with a favourable outcome. The combination of M1 or M2 and absent pupillary reactions to light and absent corneal reflexes on day 3 was present in 14.9% of patients with an unfavourable and none of the patients with a favourable outcome. None of the patients with a favourable outcome had a bilaterally absent somatosensory evoked potential of the median nerve. The value of electroencephalogram patterns in predicting outcome was low, except for reactivity to noxious stimuli.

Conclusions

No single clinical or electrophysiological parameter has sufficient accuracy to determine prognosis and decision making in patients after cardiac arrest, treated with hypothermia.     

Postresuscitation hemodynamics during therapeutic hypothermia after out-of-hospital cardiac arrest with ventricular fibrillation: A retrospective study

Aims of the study

To evaluate the incidence of postresuscitation myocardial depression (PRMD) and hemodynamical parameters associated with PRMD in patients treated with therapeutic hypothermia (TH) after out-of-hospital cardiac arrest with ventricular fibrillation (OHCA-VF).

Methods

Analysis of hemodynamical data from computerized clinical databases of two academic ICUs during two year period. We analyzed hemodynamical data from a subgroup of patients with pulmonary artery catheter (PAC). We defined PRMD as a cardiac index (CI) less than 1.5 l/(min m²) any time during the first 12 h and compared clinical variables and hemodynamical parameters in patients with or without PRMD.

Results

Of 120 included patients PAC monitoring was used in 47 (39%). Of 47, 31 (66%, 95% CI 52% to 80%) developed PRMD. There was no difference in urinary output, lactate, mean arterial or central venous pressures or mixed venous saturation between patients with or without PRMD. Low CI was reversed with dobutamine infusion. Presence or absence PRMD was not associated with 6-month neurological outcome.

Conclusion

Two-thirds of the OHCA-VF patients develops transient postresuscitation myocardial depression not easily detected without monitoring of CI during therapeutic hypothermia. Further controlled studies are warranted to evaluate the value of different hemodynamic targets and monitoring after cardiac arrest in terms of outcome.     

Survey on current practices for neurological prognostication after cardiac arrest

PurposeTo investigate current practices and timing of neurological prognostication in comatose cardiac arrest patients.MethodsAn anonymous questionnaire was distributed to the 8000 members of the European Society of Intensive Care Medicine during September and October 2012. The survey had 27 questions divided into three categories: background data, clinical data, decision-making and consequences.ResultsA total of 1025 respondents (13%) answered the survey with complete forms in more than 90%. Twenty per cent of respondents practiced outside of Europe. Overall, 22% answered that they had national recommendations, with the highest percentage in the Netherlands (>80%). Eighty-nine per cent used induced hypothermia (32–34 °C) for comatose cardiac arrest patients, while 11% did not. Twenty per cent had separate prognostication protocols for hypothermia patients. Seventy-nine per cent recognized that neurological examination alone is not enough to predict outcome and a similar number (76%) used additional methods. Intermittent electroencephalography (EEG), brain computed tomography (CT) scan and evoked potentials (EP) were considered most useful. Poor prognosis was defined as cerebral performance category (CPC) 3–5 (58%) or CPC 4–5 (39%) or other (3%). When prognosis was considered poor, 73% would actively withdraw intensive care while 20% would not and 7% were uncertain.ConclusionNational recommendations for neurological prognostication after cardiac arrest are uncommon and only one physician out of five uses a separate protocol for hypothermia treated patients. A neurological examination alone was considered insufficient to predict outcome in comatose patients and most respondents advocated a multimodal approach: EEG, brain CT and EP were considered most useful. Uncertainty regarding neurological prognostication and decisions on level of care was substantial.