Favorable Neurological Survival Research Articles

Abstract 18794: Systemic Heparin Use and Outcomes in Cardiac Arrest Patients Treated With Therapeutic Hypothermia Without Coronary Intervention

Introduction: The effects of hypothermia on hemostatic function are complex and poorly understood. While cardiac arrest and CPR can elicit a pro-inflammatory, pro-coagulant state, hypothermia may alter platelet count, activation and aggregation. Hypothesis: We hypothesized that treatment with systemic heparin during therapeutic hypothermia (TH) is associated with improved neurologic outcomes. Methods: We conducted a retrospective study of 157 cardiac arrest survivors treated with TH at our institution from 2007-2014. A priori, we excluded TH patients (pts) presenting with an acute coronary syndrome requiring percutaneous coronary intervention, pulmonary embolus, venous thrombosis or need for mechanical circulatory support. We used a multivariable logistic regression model to examine the relationship between systemic heparin and neurologic outcome (Cerebral Performance Category score 1-2=good; 3-5=poor) as well as inpatient survival. We also performed a chi-square analysis for the secondary endpoint of major bleeding. Results: Mean age was 57.0 (+/- 16.2) years; 86 (54%) pts were male; and 75 (47.8%) pts had an initial rhythm of ventricular tachycardia or ventricular fibrillation. At discharge, 48 (30.6%) pts had a good neurologic outcome and 23 (14.7%) pts suffered from a major bleed. Systemic heparin was administered to 48 (30.6%) pts, and was neither associated with favorable neurologic outcome (OR 0.99, CI 0.39-2.56, p=0.991) nor inpatient survival (OR 1.28, CI 0.54-3.05, p=0.574). The risk of bleeding with heparin was 2.08 (CI 0.99-4.38, p=0.052). Conclusions: In our cohort, indiscriminate use of systemic heparin during TH post-cardiac arrest was not associated with improved neurologic outcomes. Conversely, a trend towards increased risk of major bleeding was noted.

Alignment of Do-Not-Resuscitate Status With Patients' Likelihood of Favorable Neurological Survival After In-Hospital Cardiac Arrest.

After patients survive an in-hospital cardiac arrest, discussions should occur about prognosis and preferences for future resuscitative efforts. To assess whether patients' decisions for do-not-resuscitate (DNR) orders after a successful resuscitation from in-hospital cardiac arrest are aligned with their expected prognosis. Within Get With The Guidelines-Resuscitation, we identified 26,327 patients with return of spontaneous circulation (ROSC) after in-hospital cardiac arrest between April 2006 and September 2012 at 406 US hospitals. Using a previously validated prognostic tool, each patient's likelihood of favorable neurological survival (ie, without severe neurological disability) was calculated. The proportion of patients with DNR orders within each prognosis score decile and the association between DNR status and actual favorable neurological survival were examined. Do-not-resuscitate orders within 12 hours of ROSC. Likelihood of favorable neurological survival. Overall, 5944 (22.6% [95% CI, 22.1%-23.1%]) patients had DNR orders within 12 hours of ROSC. This group was older and had higher rates of comorbidities (all P < .05) than patients without DNR orders. Among patients with the best prognosis (decile 1), 7.1% (95% CI, 6.1%-8.1%) had DNR orders even though their predicted rate of favorable neurological survival was 64.7% (95% CI, 62.8%-66.6%). Among patients with the worst expected prognosis (decile 10), 36.0% (95% CI, 34.2%-37.8%) had DNR orders even though their predicted rate for favorable neurological survival was 4.0% (95% CI, 3.3%-4.7%) (P for both trends <.001). This pattern was similar when DNR orders were redefined as within 24 hours, 72 hours, and 5 days of ROSC. The actual rate of favorable neurological survival was higher for patients without DNR orders (30.5% [95% CI, 29.9%-31.1%]) than it was for those with DNR orders (1.8% [95% CI, 1.6%-2.0%]). This pattern of lower survival among patients with DNR orders was seen in every decile of expected prognosis. Although DNR orders after in-hospital cardiac arrest were generally aligned with patients' likelihood of favorable neurological survival, only one-third of patients with the worst prognosis had DNR orders. Patients with DNR orders had lower survival than those without DNR orders, including those with the best prognosis.

Favorable Outcome and Survival Using a Hypothermia Protocol After Successful Cardiopulmonary Resuscitation.

Use of mild therapeutic hypothermia to goal 32 34 °C, after return of spontaneous circulation (ROSC) in cardiac arrest patients, has been shown to increase the rates of survival and favorable neurological outcomes [1, 2]. The American Heart Association (AHA) recommends mild therapeutic hypothermia after ROSC for out-of-hospital cardiac arrest with an initial documented rhythm of ventricular fibrillation (class I, level of evidence B) [3]. International resuscitation guidelines also support mild therapeutic hypothermia as the best medical practice for shockable rhythms in patients resuscitated from cardiac arrest due to ventricular fibrillation and pulseless ventricular tachycardia after ROSC [4]. Herein, we wish to notify the readers on a case of therapeutic hypothermia after ROSC in a young man associated with favorable neurologic outcome and survival. A 34-yearold electrical worker is brought to the emergency department (ED) by co-workers having been injured by electrical strike at work. On arrival in the ED, he had a Glasgow coma score (GCS) of 3/15 and dilated sluggish pupils. Additionally, there were no heartbeats or respiration. Cardiac monitoring revealed ventricular fibrillation and the patient received treatment with 150-J biphasic waveform shock. Cardiopulmonary resuscitation (CPR) was immediately instituted after the shock. After 2 min of CPR, ROSC was achieved and his rhythm has restored to sinus rhythm. Neither epinephrine nor antidysrhythmic agents were administered. He was resuscitated succesufully but yet remained comatose after CPR at the ED, following vital signs: GCS 8, heart rate 110/min, and blood pressure 80/50 mm Hg. Advanced cardiac life support measures were initiated (i.e., controlled intravenous fluid support, administration of dopamine, adequate oxygenation, and support of respiration with bag ventilation) following ROSC in the ED. Furthermore, therapeutic hypothermia protocol was started immediately with ice packs in the ED to decrease the patient’s temperature below 34 °C. Two hours after admission to the ED, he was transferred to the intensive care unit (ICU) for optimal care. Therapeutic cooling was maintained for 24 h by gel-circulation cooling pads (temperature management system; Artric Sun® 5000) in the ICU, and the patient was discharged home with mild neurologic deficit on ICU day 20. Therapeutic hypothermia is associated with favorable neurologic outcome and survival in patients who have experienced cardiac arrest and resuscitated succesufully, as it was in the present case. This therapy should be started as quickly as possible in post-cardiac arrest care patients, particularly with shockable cardiac arrest rhythms.

Abstract 3: Defining the Association of Do-Not-Attempt-Resuscitate Orders with Patients’ Likelihood of Survival after In-Hospital Cardiac Arrest

Background: The long-term prognosis after In-Hospital Cardiac Arrest (IHCA) is variable, but often triggers discussions about further resuscitative efforts. Whether Do-Not-Attempt-Resuscitation (DNAR) orders after IHCA are aligned with patients’ likelihood of meaningful neurological survival is unknown. Methods: Using the Get With the Guidelines-Resuscitation registry, we identified 42,537 patients between 1/2000 and 9/2012 who achieved return of spontaneous circulation (ROSC) after IHCA. Each patient’s likelihood of meaningful survival without severe neurological disability (Cerebral Performance Category score ≤2) was calculated using the previously validated CASPRI prediction model. We examined the proportion of patients made DNAR within each CASPRI score decile to determine whether end-of-life decision-making was correlated with predicted likelihood of favorable neurological survival. Results: Overall, 26,198 patients (61.6%) were made DNAR after ROSC. These patients were older (68.7 ± 15.9 vs. 63.1 ± 17.1) and had higher rates of multiple comorbidities (all P &lt;0.05). Among those with the best prognostic CASPRI scores (Decile 1), 34.6% were made DNAR after ROSC, as compared with 74.2% among those with the worst prognosis (Decile 10; P for trend &lt;0.001). (Figure 1) Only 567 (2.2%) patients made DNAR survived to discharge without severe neurological disability. This rate was consistently low even in the CASPRI deciles with a high predicted likelihood of a good survival outcome (e.g., 6.4% in Decile 1). In contrast, 40.4% of patients not made DNAR survived without severe neurological disability, with a substantially higher rate in the lower CASPRI deciles (e.g., 74.7% in Decile 1). Conclusion: Among patients successfully resuscitated from IHCA, we found reassuring evidence that the decision to adopt DNAR status was generally aligned with a patient’s predicted likelihood of meaningful neurological survival. However, discordance between predicted and actual rates of this outcome among DNAR patients with the highest likelihood of survival suggest either competing, unmeasured interests or the need to inform physicians and patients about prognosis when discussing goals of care. Whether the use of the CASPRI score can further assist in these discussions requires prospective testing.

Using risk prediction tools in survivors of in-hospital cardiac arrest.

In-hospital cardiac arrests are common and associated with poor outcomes. Predicting the likelihood of favorable neurological survival following resuscitation from an in-hospital cardiac arrest could provide important information for physicians and families. In this article, we review the literature regarding predictors of survival following in-hospital cardiac arrest. Specifically, we describe the Cardiac Arrest Survival Postresuscitation In-hospital (CASPRI) score that was recently developed and validated using data from the Get With the Guidelines-Resuscitation registry. The CASPRI score includes 11 predictor variables: age, initial cardiac arrest rhythm, defibrillation time, baseline neurological status, duration of resuscitation, mechanical ventilation, renal insufficiency, hepatic insufficiency, sepsis, malignancy, and hypotension. The score is simple to use at the bedside, has excellent discrimination and calibration, and provides robust estimates of the probability of favorable neurological survival after an in-hospital cardiac arrest. Thus, CASPRI may be valuable in establishing expectations by physicians and families in the critical period after these high-risk events.

Course of quantitative ventricular fibrillation waveform measure and outcome following out-of-hospital cardiac arrest

Quantitative measures of the ventricular fibrillation waveform at the outset of resuscitation are associated with survival. However, little is known about the course of these measures during resuscitation and how this course is related to outcome. The purpose of this study was to determine how waveform measures change over the course of resuscitation and whether these changes might be used to guide resuscitation. We evaluated 390 persons treated by emergency providers following out-of-hospital ventricular fibrillation arrest. We assessed the ventricular fibrillation waveform using the amplitude spectrum area (AMSA) from the defibrillator's continuous electrocardiogram measured before each of the first three shocks. We used logistic regression to evaluate the relationship of AMSA and the change in AMSA with favorable neurologic survival as determined by the Cerebral Performance Category at hospital discharge 1-2. Of the 390 patients who received an initial shock, 273 required a second shock and 210 required a third shock. The mean (standard deviation) for AMSA was 9.64 (0.52) for the 873 total shock cycles. AMSA₁ measured before the first shock was strongly associated with favorable neurologic survival (odds ratio [OR] 3.40, 95% confidence interval [CI] [2.48, 4.66] for 1 SD change). We observed a similar relationship for second-shock AMSA₂ (OR 3.53, 95% CI [2.42, 5.14]) and third-shock AMSA₃ (OR 3.10, 95% CI [2.03, 4.73]). The median change in AMSA was 0.24 for ΔAMSA₁₋₂ and 0.21 for ΔAMSA₂₋₃. A positive median change in AMSA between shocks was associated with favorable neurologic survival (OR 1.44, 95% CI [1.16, 1.80] for ΔAMSA₁₋₂ and OR 1.31, 95% CI [1.01, 1.71] for ΔAMSA₂₋₃). Given their prognostic and dynamic qualities, quantitative waveform measures may provide an effective real-time strategy to guide individual treatment and improve survival.

Cardiac arrest caused by acute intoxication—insight from a registry

IntroductionThe aim of the study was to evaluate the epidemiology and outcome after cardiac arrest caused by intoxication. MethodsA retrospective analysis of 1991 to 2010 medical record of patients experiencing cardiac arrest caused by self-inflicted, intentional intoxication was performed. The setting was an emergency department of a tertiary care university hospital. The primary end point was the presentation of epidemiologic data in relation to favorable neurologic outcome, defined as cerebral performance categories 1 or 2 and 180-day survival. Furthermore, the patients were subdivided into a single-substance and polysubstance group, depending on the substances causing the intoxication. ResultsOf 3644 patients admitted to our department, 99 (2.7%) with a median age of 26 (interquartile range, 19-42) years (37% female) were included. Cardiac arrest was witnessed in 62 cases (63%). Eleven patients (11%) received basic life support by bystanders, and 11 (11%) had a shockable rhythm in the initial electrocardiogram. The combined end point “good survival” was achieved by 34 patients (34%). Cardiac arrest occurred out of hospital in 73 patients (74%) and in-hospital in 26 patients (26%). A single substance causing the intoxication was found in 56 patients (56%). Opiates were the leading substance, with 25 patients (25%) using them. ConclusionCardiac arrest caused by intoxication is found predominately in young patients. Overall, favorable neurologic survival was achieved in 34%. Opiate-related cardiac arrest was associated with poor survival and a high incidence of neurologic deficits.

Regional variability in survival outcomes of out-of-hospital cardiac arrest: The All-Japan Utstein Registry

ObjectiveThere is a paucity of studies on the degree of regional variability in out-of-hospital cardiac arrest (OHCA) outcomes, particularly in neurological outcome. This study aimed to determine whether there is a significant regional variation in survival outcomes of OHCA across Japan. MethodsWe analyzed a prospective, nation-wide, population-based database (All-Japan Utstein Registry) involving all Japanese individuals who had non-traumatic OHCA resuscitated by emergency responders from January 2005 through December 2010. The primary study endpoint was favourable neurological survival at 1 month, defined as Cerebral Performance Category 1 or 2. We compared unadjusted and multivariable-adjusted rates of the outcome among seven geographic regions. ResultsIn the total catchment population of 128 million, there were 539,641 non-traumatic OHCA patients. Unadjusted neurologically favourable survival varied across regions from 1.9% to 3.1% (rate difference, 1.2%; 95%CI, 1.0–1.3%); the Northeast region had a significantly lower rate compared to the Midwest region (unadjusted rate ratio, 0.62; 95%CI, 0.60–0.64). This disparity became larger after adjusting for patient- and prehospital-level confounders (adjusted rate ratio, 0.52; 95%CI, 0.51–0.54). Among 35,153 OHCA patients with return of spontaneous circulation, unadjusted neurologically favourable survival varied from 26.4% to 34.7% (rate difference, 8.3%; 95%CI, 6.6–10.1%); the East region had a significantly lower rate compared to the Midwest region (adjusted rate ratio, 0.72; 95%CI, 0.68–0.76). ConclusionIn this prospective, nation-wide, population-based study in Japan, we found a two-fold regional difference in neurologically favourable survival after OHCA, suggesting regional disparities in prehospital care and in-hospital post-resuscitation care.

Improved Early Postresuscitation EEG Activity for Animals Treated with Hypothermia Predicted 96 hr Neurological Outcome and Survival in a Rat Model of Cardiac Arrest

Purpose. To investigate the effect of hypothermia on 96 hr neurological outcome and survival by quantitatively characterizing early postresuscitation EEG in a rat model of cardiac arrest. Materials and Methods. In twenty male Sprague-Dawley rats, cardiac arrest was induced through high frequency transesophageal cardiac pacing. Cardiopulmonary resuscitation was initiated after 5 mins untreated arrest. Immediately after resuscitation, animals were randomized to either 2 hrs of hypothermia (N = 10) or normothermia (N = 10). EEG, ECG, aortic pressure, and core temperature were continuously recorded for 6 hrs. Neurological outcome was evaluated daily during the 96 hrs postresuscitation period. Results. No differences in the baseline measurements and resuscitation outcome were observed between groups. However, 96 hr neurological deficit score (204 ± 255 versus 500 ± 0, P = 0.005) and survival (6/10 versus 0/10, P = 0.011) were significantly better in the hypothermic group. Quantitative analysis of early postresuscitation EEG revealed that burst frequency and spectrum entropy were greatly improved in the hypothermic group and correlated with 96 hr neurological outcome and survival. Conclusion. The improved burst frequency during burst suppression period and preserved spectrum entropy after restoration of continuous background EEG activity for animals treated with hypothermia predicted favorable neurological outcome and survival in this rat model of cardiac arrest.

Abstract 259: National Variability in Survival Outcomes of Out-of-Hospital Cardiac Arrest: The All-Japan Utstein Registry

Introduction Health and policy implications of national variability in survival outcomes of out-of-hospital cardiac arrest (OHCA) remain to be determined. Hypothesis We tested the hypothesis that survival outcomes of OHCA would differ across geographic regions in Japan. Methods Analysis of a prospective nation-wide population-based dataset of the whole population across Japan involving all patients who had a non-traumatic OHCA resuscitated by emergency responders from January 2005 through December 2010. The study endpoints were 1-month survival and favorable neurological survival 1 month after an OHCA, defined as Cerebral Performance Category 1 or 2. We compared unadjusted and multivariable-adjusted rates of the outcomes among 7 geographic regions using regression model with generalized estimating equations to control for patient- and prehospital-level characteristics (Table). Results In the total catchment population of 128 million, 670 313 patients with OHCA were documented. Of 660 672 resuscitation attempts, 539 641 non-traumatic OHCA patients were eligible for analysis. The adjusted incidence of OHCA per 100 000 population ranged from 58.9 to 78.8 (median, 65.3). One-month survival ranged from 3.7% to 6.1%, with a median of 5.6%; we observed a large variation among regions in multivariable adjusted rate of 1-month survival, ranging from 3.8% to 6.5% (median, 4.7%). Similarly, neurologically favorable survival varied by region from 1.9% to 3.0%, with a median of 2.5%; adjusted rate of neurologically favorable survival ranged from 1.9% to 3.6% (median, 2.7%), with significant differences across regions (P&lt;.001). Conclusion In this nation-wide population-based study in Japan, there were significant and important regional differences in OHCA survival outcomes.

A Validated Prediction Tool for Initial Survivors of In-Hospital Cardiac Arrest

Accurate estimation of favorable neurological survival after in-hospital cardiac arrest could provide critical information for physicians, patients, and families. Within the Get With the Guidelines-Resuscitation registry, we identified 42,957 patients from 551 hospitals admitted between January 2000 and October 2009 who were successfully resuscitated from an in-hospital cardiac arrest. A simple prediction tool for favorable neurological survival in patients successfully resuscitated from an in-hospital cardiac arrest was developed using multivariate logistic regression, with two-thirds of the sample randomly selected as the derivation cohort and one-third as the validation cohort. Favorable neurological status was defined as the absence of severe neurological deficits (cerebral performance category score of ≤2). Rates of favorable neurological survival were similar in the derivation cohort (7052 patients [24.6%]) and validation cohort (3510 patients [24.5%]). Eleven variables were associated with favorable neurological survival: younger age, initial cardiac arrest rhythm of ventricular fibrillation or pulseless ventricular tachycardia with a defibrillation time of 2 minutes or less, baseline neurological status without disability, arrest location in a monitored unit, shorter duration of resuscitation, and absence of mechanical ventilation, renal insufficiency, hepatic insufficiency, sepsis, malignant disease, and hypotension prior to the arrest. The model had excellent discrimination (C statistic of 0.80 for both the derivation and validation cohorts) and calibration. The prediction tool demonstrated the ability to identify patients across a wide range of rates of favorable neurological survival: patients in the top decile had a 70.7% probability of this outcome, whereas patients in the bottom decile had a 2.8% probability. Among successfully resuscitated patients with an in-hospital cardiac arrest, a simple, bedside prediction tool provides robust estimates of the probability of favorable neurological survival. This tool permits accurate prognostication after cardiac arrest for physicians, patients, and families.

Preserved heart rate variability during therapeutic hypothermia correlated to 96 hrs neurological outcomes and survival in a pig model of cardiac arrest*

Therapeutic hypothermia initiated with cardiopulmonary resuscitation improves neurologic outcomes and survival after prolonged cardiac arrest. However, the potential mechanism by which hypothermia improves neurologic outcomes remains unclear. In the current study, we investigated the effect of rapid head cooling on 96-hr neurologic outcomes and survival by heart rate variability analysis in a pig model of prolonged cardiac arrest. Prospective randomized controlled animal study. University-affiliated research laboratory. Yorkshire-X domestic pigs (Sus scrofa). A protocol of 10 mins of untreated ventricular fibrillation followed by 5 mins of cardiopulmonary resuscitation in a pig model of cardiac arrest was used in this study. Sixteen male domestic pigs weighing between 39 and 45 kg were randomized into two groups, hypothermia (n = 8) and control (n = 8). For the hypothermia group, intranasal-induced head cooling was initiated with cardiopulmonary resuscitation and persisted for 4 hrs after resuscitation. For the control group, cardiopulmonary resuscitation was started with normothermia. Time and frequency domain heart rate variability was calculated in 5-min sections of electrocardiographic recordings at baseline and 4 hrs after resuscitation. Neurologic outcomes were evaluated every 24 hrs during the 96-hr postresuscitation observation period. No differences in the baseline measurement and resuscitation outcome were observed between the groups. However, the 96-hr cerebral performance categories of the hypothermic group were significantly lower than control (1.0 ± 0.0 vs. 4.0 ± 1.9, p = .003). Four hrs after resuscitation, mean RR interval, heart rate variability triangular index, and normalized very-low-frequency power were restored to baseline in the hypothermia group. Square root of the mean squared differences of successive RR intervals and SD of instantaneous RR intervals were significantly improved in the cooled animals compared with controls. A significant correlation between 4-hr heart rate variability and 96-hr cerebral performance category was observed in this study. Selective head cooling maintains a certain level of autonomic nervous system function in this pig model of cardiac arrest. The preserved heart rate variability during postresuscitation hypothermia was associated with favorable 96-hr neurologic recovery and survival.

Abstract 173: Cardiogenic Shock in Cardiac Arrest No Longer a Contraindication for Therapeutic Hypothermia

Introduction: Therapeutic hypothermia (TH) is neuroprotective and increases survival in cardiac arrest patients. Cardiac arrest is often seen in the setting of acute myocardial infarction (MI), and cardiogenic shock is a known poor prognostic factor. Methods: “Cool It” is a comprehensive TH protocol integrated into a regional STEMI network. From Feb 2006 to July 2010, 192 consecutive cardiac arrest patients who remained unresponsive following return of spontaneous circulation were enrolled in the Cool It protocol, regardless of initial rhythm or hemodynamic status. We hypothesize patients in cardiogenic shock secondary to MI treated with primary PCI will have greater survival and neurologic outcome than those without concurrent MI. Results: Of the 192 patients, 77 (40.1%) were in cardiogenic shock. Survival with favorable neurologic outcome (CPC 1 or 2) was poorer in cardiogenic shock patients than non-cardiogenic shock patients, 34/77 (44.2%) vs. 60/115 (52.2%) p=0.28, but not statistically significantly. Of those in cardiogenic shock, 32 (41.6%) had ST elevation on EKG, and a total of 42 (54.6%) were found to have an acute occlusion by angiography. Culprit arteries were: LAD n=19 (45.2%), RCA n=14 (33.3%), CMX n=5 (11.9%), L main n=4 (9.5%), and 39/42 (92.9%) and were successfully reperfused and stented. For patients with cardiogenic shock, survival with favorable neurologic outcome (CPC 1 or 2) was greater in patients with concurrent MI than without MI, 21/42 (50.0%) vs. 9/35 (25.7%) p=0.03. Cardiogenic shock with LAD lesions had the greatest favorable neurologic survival compared to other lesions, 13/19 (68.4%) vs. 8/23 (34.8%) p=0.03. Non-LAD lesion cardiogenic shock had no statistically significant survival or neurologic benefit over cardiogenic shock without concurrent MI, 8/23 (34.8%) vs. 9/35 (25.7%) p=0.46. Conclusion: TH should be the standard of care for unresponsive cardiac arrest patients in cardiogenic shock. Patients with cardiogenic shock and concurrent LAD STEMI have improved survival and neurologic outcomes than those cardiogenic shock patients without concurrent STEMI. Cardiogenic shock should no longer be considered a contraindication to TH, especially with concurrent STEMI.

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

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

Anesthesia Literature Review

Anesthesia Literature Review

Vasopressin for in-hospital pediatric cardiac arrest: Results from the American Heart Association National Registry of Cardiopulmonary Resuscitation*

To describe the landscape of vasopressin uses reported to the American Heart Association National Registry of cardiopulmonary resuscitation (CPR) and test the hypothesis that vasopressin use will be associated with improved return of a sustained circulation (ROSC) following in-hospital pediatric cardiac arrest. Multicentered, national registry of in-hospital CPR. One hundred seventy-six North American Hospitals reporting to registry from October 1999 to November 2004. Totally, 1293 consecutive pediatric patients with pulseless cardiac arrest meeting criteria for analysis identified from a registry of all patients resuscitated for cardiac arrest. Inclusion criteria were age <18 years, chest compressions and/or defibrillation, in-hospital location, and documented resuscitation record. None. Prearrest, event, cardiopulmonary resuscitation, and postresuscitation variables were collected. Primary outcome variable was ROSC >20 minutes. Secondary survival outcomes included 24 hour, discharge and favorable neurologic survival on hospital discharge. Descriptive, univariate, and multivariable analysis to evaluate the association of vasopressin with survival outcomes were performed. Only 5% of patients received vasopressin in this review. Vasopressin was most often given in a pediatric hospital (57%) and in and intensive care setting (76.6%). Patients who were given vasopressin had longer arrest duration (median 37 minutes) vs. those who did not (24 minutes) (p = 0.004). In multivariate analysis, vasopressin was associated with worse ROSC but no difference in 24 hours or discharge survival. Vasopressin was given infrequently in in-hospital cardiac arrest. It was most likely to be given in an intensive care setting, and in a pediatric hospital. Multivariate analysis shows an association with vasopressin use and worse ROSC.

Cerebral oximetry in out-of-hospital cardiac arrest: standard CPR rarely provides detectable hemoglobin–oxygen saturation to the frontal cortex

Favorable neurological survival in out-of-hospital cardiac arrest (OOHCA) may be influenced by cerebral perfusion during resuscitation. Cerebral oximetry (COx) provides a portable, noninvasive, real-time index of cerebral perfusion that has not been studied in OOHCA. This study examined the feasibility of using COx to measure cerebral perfusion during OOHCA. As a secondary aim, we tested the hypothesis that cerebral perfusion, measured by COx, would decrease with hyperventilation. Subjects were patients with medical OOHCA. A physician responded to the scene of cardiac arrest calls and applied an INVOS 3000 COx probe (Somanetics) to the frontal skull. In a cross-over design, readings were recorded for 2 min while ventilation rate was maintained at 10/min, then for 2 min at 24/min. COx readings were recorded by the oximeter and manually by the investigator. Statistical analyses were done using a paired t-test. Sixteen subjects were enrolled, four had return of pulses. COx reliably detected cortical oxygenation in only one subject during cardiac arrest. None of 16 patients exhibited consistently detectable levels of oxygen during cardiac arrest. In three subjects with ROSC, readings increased with return of pulses and with increasing blood pressure. In a fourth subject the protocol was completed and the device removed, subsequently ROSC was noted and the device re-applied. No patient exhibited any change in oxygen levels with variation of ventilation rates during CPR. The use of cerebral oximetry during OOHCA is feasible. In our sample of OOHCA patients, cerebral perfusion is rarely detectable using an oximeter during CPR. Ventilation rate does not alter the oximeter readings. It is possible that the current standard mechanical method of cardiopulmonary resuscitation provides little or no cerebral oxygenation during OOHCA.