International variation in survival after out-of-hospital cardiac arrest: A validation study of the Utstein template

INTRODUCTION

Out-of-hospital cardiac arrest (OHCA) survival varies greatly between communities. The Utstein template was developed and promulgated to improve the comparability of OHCA outcome reports, but it has undergone limited empiric validation. We sought to assess how much of the variation in OHCA survival between emergency medical services (EMS) across the globe is explained by differences in the Utstein factors. We also assessed how accurately the Utstein factors predict OHCA survival.

METHODS

We performed a retrospective analysis of patient-level prospectively collected data from 12 OHCA registries from 12 countries for the period 1 Jan 2006 through 31 Dec 2011. We used generalized linear mixed models to examine the variation in survival between EMS agencies (n=232).

RESULTS

Twelve registries contributed 86,759 cases. Patient arrest characteristics, EMS treatment and patient outcomes varied across registries. Overall survival to hospital discharge was 10% (range, 6% to 22%). Overall survival with Cerebral Performance Category of 1 or 2 (available for 8/12 registries) was 8% (range, 2% to 20%). The area-under-the-curve for the Utstein model was 0.85 (Wald CI: 0.85-0.85). The Utstein factors explained 51% of the EMS agency variation in OHCA survival.

CONCLUSIONS

The Utstein factors explained 51% of the variation in survival to hospital discharge among multiple large geographically separate EMS agencies. This suggests that quality improvement and public health efforts should continue to target modifiable Utstein factors to improve OHCA survival. Further study is required to identify the reasons for the variation that is incompletely understood.

Hypoxic liver injury after in- and out-of-hospital cardiac arrest: Risk factors and neurological outcome

BACKGROUND

Hypoxic liver injury (HLI) is a frequent and life-threatening complication in critically ill patients that occurs in up to ten percent of critically ill patients. However, there is a lack of data on HLI following cardiac arrest and its clinical implications on outcome. Aim of this study was to investigate incidence, outcome and functional outcome of patients with HLI after in-hospital cardiac arrest (IHCA) and out-of-hospital cardiac arrest (OHCA).

METHODS

We conducted an analysis of a cardiac arrest registry data over a 7-year period. All patients with non-traumatic OHCA and IHCA with return of spontaneous circulation (ROSC) treated at the emergency department of a tertiary care hospital were included in the study. HLI was defined according to established criteria. Predictors of HLI, occurrence, clinical and neurological outcome were assessed using multivariable regression.

RESULTS

Out of 1068 patients after IHCA and OHCA with ROSC, 219 (21%) patients developed HLI. Rate of HLI did not differ significantly in IHCA and OHCA patients. Multivariate regression analysis identified time-to-ROSC [OR 1.18, 95% CI (1.01-1.38); p < 0.05], presence of cardiac failure [OR 2.57, 95% CI (1.65-4.01); p < 0.001] and Charlson comorbidity index [OR 0.83, 95% CI (0.72-0.95); p < 0.01] as independent predictors for occurrence of HLI. Good functional outcome was significantly lower in patients suffering from HLI after 28-days (35% vs. 48%, p < 0.001) and 1-year (34% vs. 44%, p < 0.001). Occurrence of HLI was associated with unfavourable neurological outcome [OR 1.74, 95% CI (1.16-2.61); p < 0.01] in multivariate regression analysis.

CONCLUSION

New onset of HLI is a frequent finding after IHCA and OHCA. HLI is associated with increased mortality, unfavourable neurological and overall outcome.

Survival to hospital discharge with biphasic fixed 360 joules versus 200 escalating to 360 joules defibrillation strategies in out-of-hospital cardiac arrest of presumed cardiac etiology

INTRODUCTION

Guidelines recommend constant or escalating energy levels for shocks after the initial defibrillation attempt. Studies comparing survival to hospital discharge with escalating vs fixed high energy level shocks are lacking. We compared survival to hospital discharge for 200 J escalating to 360 J vs fixed 360 J in patients with initial ventricular fibrillation/pulseless ventricular tachycardia in a post-hoc analysis of the Circulation Improving Resuscitation Care trial database.

METHODS AND RESULTS

Pre-shock rhythm, rhythm 5 s after shock, shock energy levels, termination of ventricular fibrillation/pulseless ventricular tachycardia (TOF), and survival to hospital discharge were recorded. Association between defibrillation strategy and survival to hospital discharge was investigated with multivariable logistic regression. The escalating energy group included 260 patients and 883 shocks vs 478 patients and 1736 shocks in the fixed-high energy group. There was no difference in survival to hospital discharge between escalating (70/255 patients, 28%) and fixed energy group (132/478 patients, 28%) (unadjusted OR 1.00, 95% CI 0.72-1.42 and adjusted OR 0.81, 95% CI 0.54-1.22, p = 0.32). First shock TOF was 86% in the escalating group compared to 83% in the fixed-high group, p = 0.27.

CONCLUSION

There was no difference in survival to hospital discharge or the frequency of TOF between escalating energy and fixed-high energy group. ClinicalTrials.gov Identifier: NCT00597207.

Age-dependent effect of targeted temperature management on outcome after cardiac arrest

BACKGROUND

In elder patients after out-of-hospital cardiac arrest, diminished neurologic function as well as reduced neuronal plasticity may cause a low response to targeted temperature management (TTM). Therefore, we investigated the association between TTM (32-34°C) and neurologic outcome in cardiac arrest survivors with respect to age.

MATERIAL AND METHODS

This retrospective cohort study included patients 18 years of age or older suffering a witnessed out-of-hospital cardiac arrest with presumed cardiac cause, which remained comatose after return of spontaneous circulation. Patients were a priori split by age into four groups (<50 years (n = 496); 50-64 years (n = 714); 65-74 years (n = 395); >75 years (n = 280)). Subsequently, within these groups, patients receiving TTM were compared to those not treated with TTM.

RESULTS

Out of 1885 patients, 921 received TTM for 24 hours. TTM was significantly associated with good neurologic outcome in patients <65 years of age whereas showing no effect in elders (65-74 years: OR: 1.49 (95% CI: 0.90-2.47); > 75 years: OR 1.44 (95% CI 0.79-2.34)).

CONCLUSION

In our cohort, it seems that TTM might not be able to achieve the same benefit for neurologic outcome in all age groups. Although the results of this study should be interpreted with caution, TTM was associated with improved neurologic outcome only in younger individuals, patients with 65 years of age or older did not benefit from this treatment.

Added value of the DIC score and of D-dimer to predict outcome after successfully resuscitated out-of-hospital cardiac arrest

BACKGROUND

Recent Korean data suggest a high prevalence of overt disseminated intravascular coagulation (DIC) and a good predictive performance of the ISTH DIC score in successfully resuscitated out-of-hospital cardiac arrest.

OBJECTIVES

We hypothesised that in a European cohort of resuscitated out-of-hospital cardiac arrest patients the prevalence of DIC is substantially lower. Furthermore, the determination of D-dimer levels at admission, but not the DIC score, could improve mortality prediction above traditional predictors.

PATIENTS/METHODS

Data were extracted from a prospective cardiac arrest registry including patients admitted between 2006 and 2015, who achieved return of spontaneous circulation and had parameters for DIC score calculation available. The primary outcome was the prevalence of overt DIC at admission. Secondary outcomes included the association of overt DIC with 30-day mortality and the contribution of the DIC score and D-dimer levels to 30-day mortality prediction using logistic regression. Three stepwise models were evaluated by receiver-operating-characteristic analysis.

RESULTS

Out of 1179 patients 388 were included in the study. Overt DIC was present in 8% of patients and associated with substantial 30-day mortality (83% vs. 39%). The AUC for model 1, including traditional mortality predictors, was 0.83. The inclusion of D-dimer levels significantly improved prognostication above traditional predictors (model 3, AUC 0.89), whereas the inclusion of the DIC Score had no effect on mortality prediction (model 2, AUC 0.83).

CONCLUSION

Overt DIC was rare in a European cohort of out-of-hospital cardiac arrest patients. D-dimer levels improved 30-day mortality prediction and provided added value to assess early mortality risk after successful resuscitation.

Out-of-hospital initiation of hypothermia in ST-segment elevation myocardial infarction: a randomised trial

Objective

To evaluate the effect of prereperfusion hypothermia initiated in the out-of-hospital setting in awake patients with ST-segment elevation myocardial infarction (STEMI) on myocardial salvage measured by cardiac MRI (CMR).

Methods

Hypothermia was initiated within 6 hours of symptom onset by the emergency medical service with surface cooling pads and cold saline, and continued in the cath lab with endovascular cooling (target temperature: ≤35°C at time of reperfusion). Myocardial salvage index (using CMR) was compared in a randomised, controlled, open-label, endpoint blinded trial to a not-cooled group of patients at day 4±2 after the event.

Results

After postrandomisation exclusion of 19 patients a total of 101 patients were included in the intention-to-treat analysis (control group: n=54; hypothermia group: n=47). Target temperature was reached in 38/47 patients (81%) in the intervention group. Study-related interventions resulted in a delay in time from first medical contact to reperfusion of 14 min (control group 89±24 min; hypothermia group 103±21 min; p<0.01). Myocardial salvage index was 0.37 (±0.26) in the control group and 0.43 (±0.27) in the hypothermia group (p=0.27). No differences in cardiac biomarkers or clinical outcomes were found. In a CMR follow-up 6 months after the initial event no significant differences were detected.

Conclusion

Out-of-hospital induced therapeutic hypothermia as an adjunct to primary percutaneous coronary intervention did not improve myocardial salvage in patients with STEMI.

Trial registration number

NCT01777750

The impact of cardiopulmonary resuscitation (CPR) manikin chest stiffness on motivation and CPR performance measures in children undergoing CPR training-A prospective, randomized, single-blind, controlled trial

BACKGROUND

Cardio-pulmonary-resuscitation (CPR) training starting at the age of 12 years is recommended internationally. Training younger children is not recommended because young children lack the physical ability to perform adequate CPR and discouragement to perform CPR later is apprehended. The aim of this study was to answer the following questions: Are younger children discouraged after CPR training? Is discouragement caused by their lack in physical ability to perform adequate chest compressions on a standard manikin and would the use of manikins with a reduced resistance affect their motivation or performance?

METHODS

We investigated the motivation and CPR performance of children aged 8-13 years after CPR training on manikins of different chest stiffness in a prospective, randomized, single-blind, controlled trial. 322 children underwent randomization and received 30 minutes CPR training in small groups at school. We used two optically identical resuscitation manikins with different compression resistances of 45kg and 30kg. Motivation was assessed with a self-administered questionnaire. Performance was measured with the Resusci®Anne SkillReporter™.

FINDINGS

Motivation after the training was generally high and there was no difference between the two groups in any of the questionnaire items on motivation: Children had fun (98 vs. 99%; P = 0.32), were interested in the training (99 vs. 98%; P = 0.65), and were glad to train resuscitation again in the future (89 vs. 91%; P = 0.89). CPR performance was generally poor (median compression score (8, IQR 1-45 and 29, IQR 11-54; P<0.001) and the mean compression depth was lower in the 45kg-resistance than in the 30kg-resistance group (33±10mm vs. 41±9; P<0.001).

CONCLUSIONS

Compression resistances of manikins, though influencing CPR performance, did not discourage 8 to 13 year old children after CPR training. The findings refute the view that young children are discouraged when receiving CPR training even though they are physically not able to perform adequate CPR.

Initial electrical frequency predicts survival and neurological outcome in out of hospital cardiac arrest patients with pulseless electrical activity

BACKGROUND

Outcome is generally poor in out of hospital cardiac arrests (OHCA) with initial non-shockable rhythms. Termination of resuscitation rules facilitate early prognostication at the scene to cease resuscitation attempts in futile situations and to proceed advanced life support in promising conditions. As pulseless electrical activity (PEA) is present as first rhythm in every 4th OHCA we were interested if the initial electrical frequency in PEA predicts survival.

METHODS

All patients >18 years of age with non-traumatic OHCA and PEA as first rhythm between August 2013 and August 2015 from the Vienna Cardiac Arrest Registry were included in this retrospective observational study. Defibrillator and epidemiological data from the emergency medical system as survival data were processed considering the initial electrical activity in PEA and 30 days survival.

RESULTS

Out of 2149 OHCA patients, a total of 504 PEA patients were eligible for analyses. These patients were stratified into 4 groups according the initial electrical frequency in PEA: 10-24/min, 25-39/min, 40-59/min, >60/min. Compared to a frequency >60/min all other subgroups were associated with higher mortality especially those with an initial electrical frequency 10-24 (adjusted OR 0.56 (0.39-0.79) p = .001 for each category chance). QRS duration in PEA did not influence outcome. Patients in the >60/min group showed a 30-days-survival rate of 22% and a good neurological outcome in 15% of all patients - comparable to shockable cardiac arrest rhythms.

CONCLUSION

Regardless of other resuscitation factors, higher initial electrical frequency in PEA is associated with increased odds of survival and good neurological outcome.

Regional cerebral oxygen saturation during cardiopulmonary resuscitation as a predictor of return of spontaneous circulation and favourable neurological outcome - A review of the current literature

INTRODUCTION

Regional cerebral oxygen saturation (rSO2) can be measured non-invasively even at no- or low-flow states. It thus allows assessment of brain oxygenation during CPR. Certain rSO2 values had been associated with return of spontaneous circulation (ROSC) and neurological outcome in the past. Clear-cut thresholds for the prediction of beneficial outcome, however, are still lacking.

METHODS

We conducted a database search to extract all available investigations on rSO2 measurement during CPR. Mean, median, and ΔrSO2 values were either taken from the studies or calculated. Thresholds for the outcome "ROSC" and "neurological outcome" were sought.

RESULTS

We retrieved 26 publications for the final review. The averaged mean rSO2 for patients achieving ROSC was 41 ± 12% vs. 30 ± 12% for non-ROSC (p = .009). ROSC was not observed when mean rSO2 remained <26%. In ROSC patients, ΔrSO2 was 22 ± 16% vs. 7 ± 10% in non-ROSC patients (p = .009). A rSO2 threshold of 36% predicted ROSC with a sensitivity of 67% and specificity of 69% while ΔrSO2 of 7% showed a sensitivity of 100% and a specificity of 86% (AUC = 0.733 and 0.893, respectively). Mean rSO2 of 47 ± 11% was associated with favourable and 38 ± 12% with poor neurological outcome. There was, however, a great overlap between groups due to scarce data.

CONCLUSION

Higher rSO2 consistently correlated with increased rates of ROSC. The discriminatory power of rSO2 to prognosticate favourable neurological outcome remains unclear. Measuring rSO2 during CPR could potentially facilitate clinical decision-making.

Reduction of Serious Adverse Events Demanding Study Exclusion in Model Development: Extracorporeal Life Support Resuscitation of Ventricular Fibrillation Cardiac Arrest in Rats

Extracorporeal life support is a promising concept for selected patients in refractory cardiogenic shock and for advanced life support of persistent ventricular fibrillation cardiac arrest. Animal models of ventricular fibrillation cardiac arrest could help to investigate new treatment strategies for successful resuscitation. Associated procedural pitfalls in establishing a rat model of extracorporeal life support resuscitation need to be replaced, refined, reduced, and reported.Anesthetized male Sprague-Dawley rats (350-600 g) (n = 126) underwent cardiac arrest induced with a pacing catheter placed into the right ventricle via a jugular cannula. Rats were resuscitated with extracorporeal life support, mechanical ventilation, defibrillation, and medication. Catheter and cannula explantation was performed if restoration of spontaneous circulation was achieved. All observed serious adverse events (SAEs) occurring in each of the experimental phases were analyzed.Restoration of spontaneous circulation could be achieved in 68 of 126 rats (54%); SAEs were observed in 76 (60%) experiments. Experimental procedures related SAEs were 62 (82%) and avoidable human errors were 14 (18%). The most common serious adverse events were caused by insertion or explantation of the venous bypass cannula and resulted in lethal bleeding, cannula dislocation, or air embolism.Establishing an extracorporeal life support model in rats has confronted us with technical challenges. Even advancements in small animal critical care management over the years delivered by an experienced team and technical modifications were not able to totally avoid such serious adverse events. Replacement, refinement, and reduction reports of serious adverse events demanding study exclusions to avoid animal resources are missing and are presented hereby.

Outcome of in- and out-of-hospital cardiac arrest survivors with liver cirrhosis

Background

Organ failure increases mortality in patients with liver cirrhosis. Data about resuscitated cardiac arrest patients with liver cirrhosis are missing. This study aims to assess aetiology, survival and functional outcome in patients after successful cardiopulmonary resuscitation (CPR) with and without liver cirrhosis.

Methods

Analysis of prospectively collected cardiac arrest registry data of consecutively hospital-admitted patients following successful CPR was performed. Patient’s characteristics, admission diagnosis, severity of disease, course of disease, short- and long-term mortality as well as functional outcome were assessed and compared between patients with and without cirrhosis.

Results

Out of 1068 patients with successful CPR, 47 (4%) had liver cirrhosis. Acute-on-chronic liver failure (ACLF) was present in 33 (70%) of these patients on admission, and four patients developed ACLF during follow-up. Mortality at 1 year was more than threefold increased in patients with liver cirrhosis (OR 3.25; 95% CI 1.33–7.96). Liver cirrhosis was associated with impaired neurological outcome (OR for a favourable cerebral performance category: 0.13; 95% CI 0.04–0.36). None of the patients with Child–Turcotte–Pugh (CTP) C cirrhosis survived 28 days with good neurological outcome. Overall nine (19%) patients with cirrhosis survived 28 days with good neurological outcome. All patients with ACLF grade 3 died within 28 days.

Conclusion

Cardiac arrest survivors with cirrhosis have worse outcome than those without. Although one quarter of patients with liver cirrhosis survived longer than 28 days after successful CPR, patients with CTP C as well as advanced ACLF did not survive 28 days with good neurological outcome.

Electronic supplementary material

The online version of this article (doi:10.1186/s13613-017-0322-1) contains supplementary material, which is available to authorized users.

The impact of airway strategy on the patient outcome after out-of-hospital cardiac arrest: A propensity score matched analysis

BACKGROUND

While guidelines mentioned supraglottic airway management in the case of out-of- hospital cardiac arrest, robust data of their impact on the patient outcome remain scare and results are inconclusive.

METHODS

To assess the impact of the airway strategy on the patient outcome we prospectively enrolled 2224 individuals suffering cardiac arrest who were treated by the Viennese municipal emergency medical service. To control for potential confounders, propensity score matching was performed. Patients were matched in four groups with a 1:1:1:1 ratio ( n=210/group) according to bag-mask-valve, laryngeal tube, endotracheal intubation and secondary endotracheal intubation after primary laryngeal tube ventilation.

RESULTS

The laryngeal tube subgroup showed the lowest 30-day survival rate among all tested devices ( p<0.001). However, in the case of endotracheal intubation after primary laryngeal tube ventilation, survival rates were comparable to the primary endotracheal tube subgroup. The use of a laryngeal tube was independently and directly associated with mortality with an adjusted odds ratio of 1.97 (confidence interval: 1.14-3.39; p=0.015). Additionally, patients receiving laryngeal tube ventilation showed the lowest rate of good neurological performance (6.7%; p<0.001) among subgroups. However, if patients received endotracheal intubation after initial laryngeal tube ventilation, the outcome proved to be significantly better (9.5%; p<0.001).

CONCLUSION

We found that the use of a laryngeal tube for airway management in cardiac arrest was significantly associated with poor 30-day survival rates and unfavourable neurological outcome. A primary endotracheal airway management needs to be considered at the scene, or an earliest possible secondary endotracheal intubation during both pre-hospital and in-hospital post-return of spontaneous circulation critical care seems crucial and most beneficial for the patient outcome.

Improvements in the quality of advanced life support and patient outcome after implementation of a standardized real-life post-resuscitation feedback system

BACKGROUND

Educational aspects in the training of advanced life support (ALS) represent a key role in critical care management of patients with out-of-hospital cardiac arrest (OHCA) and received special attention in guidelines of various international societies. While a positive association of feedback on ALS performance in training conditions is well established, data on the impact of a real-life post-resuscitation feedback on both ALS quality and outcome remain scarce and inconclusive. We aimed to elucidate the impact of a standardized post-resuscitation feedback on quality of ALS and improvements in patient outcome, in a real-life out-of-hospital setting.

METHODS

We prospectively enrolled and analyzed 2209 patients presenting with OHCA receiving resuscitation attempts by the municipal emergency medical service (EMS) of Vienna over a two-year period. A standardized post-resuscitation feedback protocol was delivered to the respective EMS-team to elucidate its impact on the quality of ALS.

RESULTS

We observed that both chest compression rates and ratios were in accordance to recommendations of recent guidelines. While interruptions of chest compressions longer than 30s declined during the observation period (-6.5%) rates of the recommended chest compressions during defibrillator-charging periods increased (+8.9%). Since the percentage of ROSC and 30-day survival remained balanced, the frequencies of both survival until hospital discharge (+6.3%) and favorable neurological outcome (+16%) in survivors significantly increased during the observation period.

CONCLUSION

Improvements in the quality of advanced life support as well the patient outcome were observed after the implementation of a standardized post-resuscitation feedback protocol.

Continuous versus intermittent neuromuscular blockade in patients during targeted temperature management after resuscitation from cardiac arrest-A randomized, double blinded, double dummy, clinical trial

AIM OF THE STUDY

Current guidelines recommend targeted temperature management to improve neurological outcome after cardiac arrest. Evidence regarding an ideal sedative/analgesic regimen including skeletal muscle paralysis is limited.

METHODS

Patients were randomized to either a continuous administration of rocuronium (continuous-NMB-group) or to a continuous administration of saline supplemented by rocuronium bolus administration if demanded (bolus-NMB-group). The primary outcome was the number of shivering episodes. Secondary outcomes included survival and neurological status one year after cardiac arrest, time to awakening, length of stay as well as required cumulative dose of rocuronium, midazolam and fentanyl.

RESULTS

Sixty-three patients (32 continuous-NMB-group; 31 bolus-NMB-group) were enrolled. Differences in baseline characteristics were not significant. Shivering episodes were detected in 94% of the patients in the bolus-NMB-group compared to 25% of the patients receiving continuous rocuronium infusion (p<0.01). The continuous-NMB-group received significant lower doses of midazolam (4.3±0.8mg/kg vs. 5.1±0.9mg/kg, p<0.01) and fentanyl (62±14μg/kg vs. 71±7μg/kg, p<0.01), but higher cumulative doses of rocuronium (7.8±1.8mg/kg vs. 2.3±1.6mg/kg, p<0.01). Earlier awakening (2 [IQR 2;3] vs. 4 [IQR 2;7.5] days, p=0.04) and decreased length of stay at the ICU (6 [IQR 3;5.9] vs. 10 [IQR 5;15] days, p=0.03) were observed in the continuous-NMB-group. There were no significant differences in survival and quality of life 12 months after cardiac arrest.

CONCLUSIONS

Continuous neuromuscular blockade during the first day after resuscitation reduced shivering, midazolam and fentanyl requirement, time to awakening and discharge from intensive care unit. There were no differences in overall survival, cooling rate and time to target temperature.

Observed survival benefit of mild therapeutic hypothermia reanalysing the Circulation Improving Resuscitation Care trial

BACKGROUND

Mild therapeutic hypothermia is argued being beneficial for outcome after cardiac arrest.

MATERIALS AND METHODS

Retrospective analysis of Circulation Improving Resuscitation Care (CIRC) trial data to assess if therapeutic cooling to 33 ± 1 °C core temperature had an association with survival. Of 4231 adult, out-of-hospital cardiac arrests of presumed cardiac origin initially enrolled, eligibility criteria for therapeutic hypothermia were met by 1812. Logistic regression was undertaken in a stepwise fashion to account for the impact on outcome of each significant difference and for the variable of interest between the groups.

RESULTS

Out-of- and in-hospital cooled were 263 (15%), only after admission cooled were 230 (13%) and not cooled were 357 (20%) patients. The group cooled out of- and in hospital had 98 (37%) survivors as compared to the groups cooled in hospital only [80 (35%)] and of those not cooled [68 (19%)]. After adjusting for known covariates (sex, age, witnessed cardiac arrest, no- and low-flow time, shockable initial rhythm, random allocation, bystander cardiopulmonary resuscitation and percutaneous coronary intervention), the odds ratio for survival comparing no cooling to out-of- plus in-hospital cooling was 0·53 [95% confidence interval (CI): 0·46-0·61, P < 0·001], and comparing to in-hospital cooling only was 0·67 (95% CI: 0·50-0·89, P = 0·006).

CONCLUSION

Mild therapeutic hypothermia initiated out of hospital and/or in hospital was associated with improved survival within this secondary analysis of the CIRC cohort compared to no therapeutic hypothermia.

Mortality in patients resuscitated from out-of-hospital cardiac arrest based on automated blood cell count and neutrophil lymphocyte ratio at admission

INTRODUCTION

The neutrophil lymphocyte ratio(NLR) is a marker of systemic inflammation. We hypothesized that admission NLR is related to mortality and that epinephrine application during resuscitation influences NLR in patients after successful resuscitation from out of hospital cardiac arrest (OHCA).

METHODS

This retrospective cohort study is based on a registry including all OHCA patients who had a presumed cardiac cause of cardiac arrest and achieved sustained ROSC prior to admission between 2005 and 2014. Patients were categorized into three groups according to the calculated NLR at admission (NLR <6, ≥6, and 'abnormal differential' indicating no differential blood cell count on patients report due to exceedance of machine predefined parameter limits). The primary outcome measure was long-term mortality after OHCA. Cox proportional hazards models were used for multivariable analysis.

RESULTS

Out of 2273 OHCA patients during the study period a total of 1188(52%) patients were eligible for analysis, of those 274(23%) were female and mean age was 64 (25-75 IQR:52-72). Compared to a NLR<6 (n=442), adjusted hazard ratio for long-term mortality was significantly higher in patients with a NLR≥6 (n=447; 1.52 (95%CI 1.03-2.24)) and in patients with abnormal differential (n=299; 3.16 (95%CI 2.02-4.97)). Epinephrine application during resuscitation did not explain the effect of NLR on mortality.

CONCLUSION

In this large retrospective cohort study of altogether >1000 OHCA patients, hospital admission NLR<6 compared to abnormal differential or NLR≥6 was associated with mortality independently from epinephrine application.

Towards an algorithm for automatic accelerometer-based pulse presence detection during cardiopulmonary resuscitation

Manual palpation is still the gold standard for assessment of pulse presence during cardiopulmonary resuscitation (CPR) for professional rescuers. However, this method is unreliable, time-consuming and subjective. Therefore, reliable, quick and objectified assessment of pulse presence in cardiac arrest situations to assist professional rescuers is still an unmet need. Accelerometers may present a promising sensor modality as pulse palpation technology for which pulse detection at the carotid artery has been demonstrated to be feasible. This study extends previous work by presenting an algorithm for automatic, accelerometer-based pulse presence detection at the carotid site during CPR. We show that accelerometers might be helpful in automated detection of pulse presence during CPR.