Cardiac arrest related to accidental hypothermia may occur at temperatures below 32 °C. Our goal was to describe the clinical characteristics and outcomes of patients who suffered from witnessed ...hypothermic cardiac arrest (CA) and assess the occurrence of hypothermic CA as a function of patient body temperature.
We conducted a systematic review of the literature on cases of hypothermic CA due to rescue collapse. Patient information data from hypothermic CA patients were collected and combined with additional unpublished data to assess the clinical characteristics and outcome of hypothermic CA patients.
A total of 214 patients was included in this systematic review. Of the 206 witnessed hypothermic CA patients with a recorded body temperature, the average body temperature was 23.9 ± 2.7 °C with five patients (2.4%) having a core body temperature of >28 °C. The highest temperature of a patient surviving hypothermic witnessed cardiac arrest without other associated risk factors for cardiac arrest was 29.4 °C. The first recorded cardiac rhythm was asystole in 33 of the 112 patients (30%) for whom this information was available. The survival rate at hospital discharge of these hypothermic cardiac arrest patients was 73% (153 of 210 patients) and most survivors had favourable neurological outcome (89%; 102 of 105 patients).
CA that is solely caused by hypothermia did not occurs for patients with a body temperature >30 °C. Our findings provide valuable new information that can be incorporated into the international clinical management guidelines of accidental hypothermia.
BackgroundOut-of-hospital cardiac arrest (OHCA) survival remains poor worldwide, especially for patients with non-shockable rhythms. A physiologically-distinct neuroprotective (NP) cardiopulmonary ...resuscitation (CPR) strategy combining automated head-up positioning (AHUP), an impedance threshold device (ITD), and manual active compression-decompression (ACD) and/or an automated suction-cup based compression device was recently shown in animal models to increase cerebral blood flow1 and neurologically-intact survival2. We assessed the effectiveness of NP-CPR on overall survival and favorable neurological survival after OHCA.MethodThis Institutional Review Board-approved observational study from a prospective NP-CPR registry compared patients treated with NP-CPR (n=227) from 6 United States pre-hospital systems with individual conventional (C) CPR control subjects (n=5,352) with data obtained from three large published North American OHCA randomized controlled trials. The primary endpoint was hospital survival. Favorable neurological function was a secondary endpoint. Multivariate logistic regression analyses (MLRA) and propensity-score 4:1 (C-CPR:NP-CPR) matching analyses (PSMA) were performed.ResultsRegardless of the presenting rhythm, faster initiation of NP-CPR was associated with higher adjusted odds ratios (ORs)95% confidence interval(CI) of survival and favorable neurological survival, using MLRA and PSMA. Specifically when NP-CPR was initiated <10 and <15 minutes after the emergency call for help, the ORsCI for survival were 4.01.7–9.6 and 2.01.1–3.8, respectively, with PSMA. When NP-CPR was initiated <12 minutes after the emergency call, the ORsCI for survival with favorable neurological function were 2.291.04–5.04 and 3.351.42–7.89 with MLRA and PSMA, respectively.ConclusionCompared with matched C-CPR controls rapid NP-CPR application was associated with a significantly higher probability of overall survival and favorable neurological survival after OHCA.ReferencesMoore JC, Segal N, Lick MC, et al. Head and thorax elevation during active compression decompression cardiopulmonary resuscitation with an impedance threshold device improves cerebral perfusion in a swine model of prolonged cardiac arrest. Resuscitation. Aug 05 2017;doi:10.1016/j.resuscitation.2017.07.03Moore JC, Salverda B, Rojas-Salvador C, Lick M, Debaty G, G Lurie K. Controlled sequential elevation of the head and thorax combined with active compression decompression cardiopulmonary resuscitation and an impedance threshold device improves neurological survival in a porcine model of cardiac arrest. Resuscitation. Jan 2021;158:220–227. doi:10.1016/j.resuscitation.2020.09.030Conflict of interestNo authors have a conflict of interest except for Keith Lurie, who is a co-inventor of the automated head up positioning device used in the study and a co-founder of AdvancedCPR Solutions LLC that funded the study.FundingAdvancedCPR Solutions LLC paid for the IRB application and provided some of the test devices to some of the test sites.
Efficient ventilation is important during cardiopulmonary resuscitation (CPR). Nevertheless, there is insufficient knowledge on how the patient’s position affects ventilatory parameters during ...mechanically assisted CPR. We studied ventilatory parameters at different positive end-expiratory pressure (PEEP) levels and when using an inspiratory impedance valve (ITD) during horizontal and head-up CPR (HUP-CPR).
In this human cadaver experimental study, we measured tidal volume (VT) and pressure during CPR at different randomized PEEP levels (0, 5 or 10 cmH2O) or with an ITD. CPR was performed, in the following order: horizontal (FLAT), at 18° and then at 35° head-thorax elevation. During the inspiratory phase we measured the net tidal volume (VT) adjusted to predicted body weight (VTPBW), reversed airflow (RAF), and maximum and minimum airway pressure (Pmax and Pmin).
Using ten thawed fresh-frozen cadavers we analyzed the inspiratory phase of 1843 respiratory cycles, 229 without CPR and 1614 with CPR. In a mixed linear model, thoracic position and PEEP significantly impacted VTPBW (p < 0.001 for each), and the insufflation time, thoracic position and PEEP significantly affected the RAF (p < 0.001 for each) and Pmax (p < 0.001). For Pmin, only PEEP was significant (p < 0.001). In subgroup analysis, at 35° VTPBW and Pmax were significantly reduced compared with the flat or 18° position.
When using mechanical ventilation during CPR, it seems that the PEEP level and patient position are important determinants of respiratory parameters. Moreover, tidal volume seems to be lower when the thorax is positioned at 35°.
The end-tidal carbon dioxide (ETCO2) is frequently measured in cardiac arrest (CA) patients, for management and for predicting survival. Our goal was to study the PaCO2 and ETCO2 in hypothermic ...cardiac arrest patients.
We included patients with refractory CA assessed for extracorporeal cardiopulmonary resuscitation. Hypothermic patients were identified from previously prospectively collected data from Poland, France and Switzerland. The non-hypothermic CA patients were identified from two French cohort studies. The primary parameters of interest were ETCO2 and PaCO2 at hospital admission. We analysed the data according to both alpha-stat and pH-stat strategies.
We included 131 CA patients (39 hypothermic and 92 non-hypothermic). Both ETCO2 (p < 0.001) and pH-stat PaCO2 (p < 0.001) were significantly lower in hypothermic compared to non-hypothermic patients, which was not the case for alpha-stat PaCO2 (p = 0.15). The median PaCO2-ETCO2 gradient was greater for hypothermic compared to non-hypothermic patients when using the alpha-stat method (46 mmHg vs 30 mmHg, p = 0.007), but not when using the pH-stat method (p = 0.10). Temperature was positively correlated with ETCO2 (p < 0.01) and pH-stat PaCO2 (p < 0.01) but not with alpha-stat PaCO2 (p = 0.5). The ETCO2 decreased by 0.5 mmHg and the pH-stat PaCO2 by 1.1 mmHg for every decrease of 1° C of the temperature. The proportion of survivors with an ETCO2 ≤ 10 mmHg at hospital admission was 45% (9/25) for hypothermic and 12% (2/17) for non-hypothermic CA patients.
Hypothermic CA is associated with a decrease of the ETCO2 and pH-stat PaCO2 compared with non-hypothermic CA. ETCO2 should not be used in hypothermic CA for predicting outcome.
Mountainous areas pose a challenge for the out-of-hospital cardiac arrest (OHCA) chain of survival. Survival rates for OHCAs in mountainous areas may differ depending on the location. Increased ...survival has been observed compared to standard location when OHCA occurred on ski slopes. Limited data is available about OHCA in other mountainous areas. The objective was to compare the survival rates with a good neurological outcome of OHCAs occurring on ski slopes (On-S) and off the ski slopes (OffS) compared to other locations (OL).
Analysis of prospectively collected data from the cardiac arrest registry of the Northern French Alps Emergency Network (RENAU) from 2015 to 2021. The RENAU corresponding to an Emergency Medicine Network between all Emergency Medical Services and hospitals of 3 counties (Isère, Savoie, Haute-Savoie). The primary outcome was survival at 30 days with a Cerebral Performance Category scale (CPC) of 1 or 2 (1: Good Cerebral Performance, 2: Moderate Cerebral Disability).
A total of 9589 OHCAs were included: 213 in the On-S group, 141 in the Off-S group, and 9235 in the OL group. Cardiac etiology was more common in On-S conditions (On-S: 68.9% vs OffS: 51.1% vs OL: 66.7%, p < 0.001), while Off-S cardiac arrests were more often due to traumatic circumstances (OffS: 39.7% vs On-S: 21.7% vs OL: 7.7%, p < 0.001). Automated external defibrillator (AED) use before rescuers' arrival was lower in the Off-S group than in the other two groups (On-S: 15.2% vs OL: 4.5% vs OffS: 3.7%; p < 0.002). The first AED shock was longer in the Off-S group (median time in minutes: OffS: 22.0 (9.5–35.5) vs On-S: 10.0 (3.0–19.5) vs OL: 16.0 (11.0–27.0), p = 0.03). In multivariate analysis, on-slope OHCA remained a positive factor for 30-day survival with a CPC score of 1 or 2 with a 1.96 adjusted odds ratio (95% confidence interval (CI), 1.02–3.75, p = 0.04), whereas off-slope OHCA had an 0.88 adjusted odds ratio (95% CI, 0.28–2.72, p = 0.82).
OHCAs in ski-slopes conditions were associated with an improvement in neurological outcomes at 30 days, whereas off-slopes OHCAs were not. Ski-slopes rescue patrols are efficient in improving outcomes.
To provide an overview of cadaver models for cardiac arrest and to identify the most appropriate cadaver model to improve cardiopulmonary resuscitation through a systematic review.
The search ...strategy included PubMed, Embase, Current contents, Pascal, OpenSIGLE and reference tracking. The search concepts included “heart arrest”, “cardiopulmonary resuscitation” and “cadavers”. All studies, published until February 2019, in English or French, on research or simulation in the field of cardiac arrest and using cadaver models were eligible for inclusion.
Overall, 29 articles out of the 244 articles located were selected. The characteristics of the studies and the cadaver models were heterogenous. Indeed, 31% of the studies lacked a proper description of the model used and its specificities. Fresh cadavers were used in 55% of the studies and chest compressions were performed in 90%. This model was appreciated for its realism in terms of mechanical properties and tissue conservation. Thiel-embalmed cadavers also showed promising results concerning lung and chest compliance. The lack of circulation stood out as the strongest limitation of all types of human cadaver models.
Four types of cadaver models are used in cardiac arrest research. The great heterogeneity of these models coupled with unequal quality in reporting makes comparisons between studies difficult. There is a need for uniform reporting and standardisation of human cadaver models in cardiac arrest research.
To date, the decision to set up therapeutic extra-corporeal life support (ECLS) in hypothermia-related cardiac arrest is based on the potassium value only. However, no information is available about ...how the analysis should be performed. Our goal was to compare intra-individual variation in serum potassium values depending on the sampling site and analytical technique in hypothermia-related cardiac arrests.
Adult patients with suspected hypothermia-related refractory cardiac arrest, admitted to three hospitals with ECLS facilities were included. Blood samples were obtained from the femoral vein, a peripheral vein and the femoral artery. Serum potassium was analysed using blood gas (BGA) and clinical laboratory analysis (CL).
Of the 15 consecutive patients included, 12 met the principal criteria, and 5 (33%) survived. The difference in average potassium values between sites or analytical method used was ≤1 mmol/L. The agreement between potassium values according to the three different sampling sites was poor. The ranges of the differences in potassium using BGA measurement were - 1.6 to + 1.7 mmol/L; - 1.18 to + 2.7 mmol/L and - 0.87 to + 2 mmol/L when comparing respectively central venous and peripheral venous, central venous and arterial, and peripheral venous and arterial potassium.
We found important and clinically relevant variability in potassium values between sampling sites. Clinical decisions should not rely on one biological indicator. However, according to our results, the site of lowest potassium, and therefore the preferred site for a single potassium sampling is central venous blood. The use of multivariable prediction tools may help to mitigate the risks inherent in the limits of potassium measurement.
ClinicalTrials.gov Identifier: NCT03096561.
Early airway management during cardiopulmonary resuscitation (CPR) prevents aspiration of gastric contents. Endotracheal intubation is the gold standard to protect airways, but supraglottic airway ...devices (SGA) may provide some protection with less training. Bag-mask ventilation (BMV) is the most common method used by rescuers. We hypothesized that SGA use by first rescuers during CPR could increase ventilation success rate and also decrease intragastric pressure and pulmonary aspiration.
We performed a randomized cross-over experimental trial on human cadavers. Protocol A: we assessed the rate of successful ventilation (chest rise), intragastric pressure, and CPR key time metrics. Protocol B: cadaver stomachs were randomized to be filled with 300 mL of either blue or green serum saline solution through a Foley catheter. Each rescuer was randomly assigned to use SGA or BMV during a 5-minute standard CPR period. Then, in a crossover design, the stomach was filled with the second color solution and another 5-minute CPR period was performed using the other airway method. Pulmonary aspiration, defined as the presence of colored solution below the vocal cords, was assessed by a blinded operator using bronchoscopy. A generalized linear mixed model was used for statistical analysis.
Protocol A: Forty-eight rescuers performed CPR on 11 cadavers. Median ventilation success was higher with SGA than BMV: 75.0% (IQR: 59.8-87.3) vs. 34.7% (IQR: 25.0-50.0), (p = 0.003). Gastric pressure and differential (maximum minus minimum) gastric pressure were lower in the SGA group: 2.21 mmHg (IQR: 1.66; 2.68) vs. 3.02 mmHg (IQR: 2.02; 4.22) (p = 0.02) and 5.70 mmHg (IQR: 4.10; 7.60) vs. 8.05 mmHg (IQR: 5.40; 11.60) (p = 0.05). CPR key times were not different between groups. Protocol B: Ten cadavers were included with 20 CPR periods. Aspiration occurred in 2 (20%) SGA procedures and 5 (50%) BMV procedures (p = 0.44).
Use of SGA by rescuers improved the ventilation success rate, decreased intragastric pressure, and did not affect key CPR metrics. SGA use by basic life support rescuers appears feasible and efficient.
Although mortality due to acute heart failure has decreased, its prevalence in France is still high. The aim of this study was to examine the quality of acute heart failure treatment in French ...emergency departments (EDs) with reference to subsequently published European Society of Cardiology (ESC) recommendations.
The medical records of patients with acute pulmonary oedema (as a marker for acute heart failure) admitted to the EDs of 11 French hospitals in 2013 were reviewed retrospectively.
A total of 834 patients were included (median interquartile range age 84 78–89 years; 48.6% male). Rates of compliance of initial management in 2013 to subsequently published 2015 recommendations were as follows: (1) thoracic ultrasound was performed in 17.3%; (2) loop diuretics were given in 75.9%; at a correct dose (among those for whom this was calculable) in 40.0% (3); intravenous nitrates were given in 21.7% of patients with systolic blood pressure>110mmHg; (4) non-invasive ventilation was initiated in 22.0% of patients with respiratory distress. Discharge summaries most often lacked a scheduled cardiologist follow-up (89.4%) and discharge patient weight (78.9%).
The early management of patients with acute pulmonary oedema (as a marker of acute heart failure) in France in 2013 was quite different to recommendations published in 2015. A programme to implement the new recommendations is in place, and a repeat evaluation will be conducted in 2017.
Malgré une diminution de la mortalité liée à l’insuffisance cardiaque aiguë, sa prévalence en France reste élevée. Le but de notre étude était d’évaluer la qualité de la prise en charge de l’insuffisance cardiaque aiguë en France dans les services d’urgence et en préhospitalier d’après les recommandations de l’European Society of Cardiology.
Les dossiers médicaux des patients admis aux urgences ou prise en charge en préhospitalier pour un tableau d’œdème pulmonaire aiguë cardiogénique (comme marqueur d’insuffisance cardiaque) dans 11 hôpitaux français en 2013 étaient analysés rétrospectivement.
Huit cent trente-quatre patients ont été inclus (âge médian 84 78–89 ans, 48,6 % d’hommes). Les taux d’adéquation en 2013 avec les recommandations publiées en 2015 étaient comme suit : (1) l’échographie thoracique était réalisée dans 17,3 % des cas ; (2) les diurétiques de l’anse étaient administrés chez 75,9 % des patients, à la dose recommandée dans 40,0 % des cas (parmi les patients chez qui elle était calculable) ; (3) les dérivés nitrés intraveineux étaient administrés pour 21,7 % des patients chez qui la pression artérielle systolique était supérieure à 110mmHg ; (4) la ventilation non invasive était mise en place pour 22,0 % des patients présentant des critères de détresse respiratoire aiguë. Le poids de sortie et un rendez-vous de suivi avec un cardiologue était le plus souvent absents des courriers de sortie d’hospitalisation (respectivement 78,9 % et 89,4 %).
La prise en charge initiale de l’œdème aiguë pulmonaire cardiogénique aux urgences et en préhospitalier en France en 2013 diffère de celle proposée dans les recommandations publiées en 2015. Un programme de diffusion des nouvelles recommandations est en cours et une évaluation de son impact sur la prise en charge des patients sera conduit en 2017.
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