Body weight does not affect defibrillation, resuscitation, or survival in patients with out-of-hospital cardiac arrest treated with a nonescalating biphasic waveform defibrillator

[Cardiac arrest under special circumstances]

These guidelines of the European Resuscitation Council (ERC) Cardiac Arrest under Special Circumstances are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. This section provides guidelines on the modifications required for basic and advanced life support for the prevention and treatment of cardiac arrest under special circumstances; in particular, specific causes (hypoxia, trauma, anaphylaxis, sepsis, hypo-/hyperkalaemia and other electrolyte disorders, hypothermia, avalanche, hyperthermia and malignant hyperthermia, pulmonary embolism, coronary thrombosis, cardiac tamponade, tension pneumothorax, toxic agents), specific settings (operating room, cardiac surgery, cardiac catheterization laboratory, dialysis unit, dental clinics, transportation [in-flight, cruise ships], sport, drowning, mass casualty incidents), and specific patient groups (asthma and chronic obstructive pulmonary disease, neurological disease, morbid obesity, pregnancy).

A simple ABCD score to stratify patients with respect to the probability of survival following in-hospital cardiopulmonary resuscitation

BACKGROUND

Cardiopulmonary resuscitation (CPR) is occurring more frequently at community hospitals but most patients undergoing CPR do not survive to discharge. Tools to predict CPR survival can be improved by the identification of high-yield clinical indicators.

OBJECTIVE

To identify variables associated with survival to discharge following in-hospital cardiac arrest.

METHODS

Retrospective cohort study of 463,530 hospital admissions from the Nationwide Inpatient Sample (2012-2016). The analysis includes adults (age ≥50) who underwent in-hospital CPR at US community hospitals.

RESULTS

Overall survival to discharge was 29.8% (95% CI: 29.5-30.1%). Age was the strongest predictor of survival and had greater prognostic value than the Charlson comorbidity index. Obesity was associated with improved survival (35.9%, 95% CI: 35.1-36.7%), whereas underweight patients had decreased survival (24.0%, 95% CI: 22.2-25.7%). Acute indicators of poor survival included hyperkalemia, hypercalcemia, and sepsis. We generated an ABCD index based upon four high-yield variables (age, body habitus, comorbidity, day of hospital admission). An ABCD score of 2 or less was a sensitive but non-specific predictor of post-CPR survival (96.8% sensitivity, 95% CI: 96.6-97.0), and those with extreme scores differed 3.8-fold with respect to post-CPR survival probability (46.0% versus 12.1%).

CONCLUSION

Age is the strongest predictor of post-CPR survival, but body habitus is also an important indicator that may currently be underutilized. Our results support improved post-CPR survival of obese patients, consistent with an 'obesity paradox'. The ABCD score provides an efficient means of risk-stratifying patients and can be calculated in less than 1 minute.

European Resuscitation Council Guidelines 2021: Cardiac arrest in special circumstances

These European Resuscitation Council (ERC) Cardiac Arrest in Special Circumstances guidelines are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. This section provides guidelines on the modifications required to basic and advanced life support for the prevention and treatment of cardiac arrest in special circumstances; specifically special causes (hypoxia, trauma, anaphylaxis, sepsis, hypo/hyperkalaemia and other electrolyte disorders, hypothermia, avalanche, hyperthermia and malignant hyperthermia, pulmonary embolism, coronary thrombosis, cardiac tamponade, tension pneumothorax, toxic agents), special settings (operating room, cardiac surgery, catheter laboratory, dialysis unit, dental clinics, transportation (in-flight, cruise ships), sport, drowning, mass casualty incidents), and special patient groups (asthma and COPD, neurological disease, obesity, pregnancy).

Association of body mass index with clinical outcomes for in-hospital cardiac arrest adult patients following extracorporeal cardiopulmonary resuscitation

BACKGROUND

Obesity might be associated with disturbance of cannulation in situation of extracorporeal cardiopulmonary resuscitation (ECPR). However, limited data are available on obesity in the setting of ECPR. Therefore, we investigated the association between body mass index (BMI) and clinical outcome in patients underwent ECPR.

METHODS

From January 2004 to December 2013, in-hospital cardiac arrest patients who had ECPR were enrolled from a single-center registry. We divided patients into four group according to BMI defined with the WHO classification (underweight, BMI < 18.5, n = 14; normal weight, BMI = 18.5-24.9, n = 118; overweight, BMI = 25.0-29.9, n = 53; obese, BMI ≥ 30, n = 15). The primary outcome was survival to hospital discharge.

RESULTS

Analysis was carried out for a total of 200 adult patients (39.5% females). Their median BMI was 23.20 (interquartile range, 20.93-25.80). The rate of survival to hospital discharge was 31.0%. There was no significant difference in survival to hospital discharge among the four groups (underweight, 35.7%; normal, 31.4%; overweight, 30.2%; obese, 26.7%, p = 0.958). Neurologic outcomes (p = 0.85) and procedural complications (p = 0.40) were not significantly different among the four groups either. SOFA score, initial arrest rhythm, and CPR to extracorporeal membrane oxygenation (ECMO) pump on time were significant predictors for survival to discharge, but not BMI.

CONCLUSION

BMI was not associated with in-hospital mortality who underwent ECPR. Neurologic outcomes at discharge or procedural complications following ECPR were not related with BMI either.

The impact of body mass index on the wearable cardioverter defibrillator shock efficacy and patient wear time

BACKGROUND

The impact of body mass index (BMI) on the shock efficacy and patient adherence among patients using a wearable cardioverter defibrillator (WCD) is unknown.

METHODS

Patients prescribed the WCD between January 1, 2008 and June 1, 2013, who experienced at least one episode of sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) and who received appropriate WCD therapy, were identified within a registry maintained by the manufacturer for regulatory, reimbursement, and administrative purposes. The registry contained patients' Body Mass Index (BMI) which was categorized as normal (18.0<BMI<25.0), overweight (25.0≤BMI<30.0) or obese (30.0≥BMI). Demographics, indication for WCD prescription and other clinical information were reviewed. Device-stored ECG, transthoracic impedance (TTI) and time worn were downloaded for analyses. A post-shock rhythm which was no longer VT or VF was considered a successful tachyarrhythmia conversion. Only the first-shock arrhythmia conversion and TTI were included in the analyses.

RESULTS

A total of 574 patients were included in the final analyses. Patient characteristics were similar across all groups except the obese group (60±11 years) was younger than the normal (63±16 years) and overweight (64±12 years, P=.001) groups. Mean length of use for normal, overweight and obese groups was 79±131, 82±202 and 55±97 days (P=.12), respectively; the median daily wear time was 21 hours among all groups. In a total of 623 VT/VF events, the median TTI was 44 ohms, 51 ohms and 65 ohms for normal, overweight and obese groups, respectively; TTI was positively correlated to BMI (r=0.33, P<.01). First-shock conversion rate was 92.9% in the normal group, 93.6% and 93.9% in the overweight and obese groups, respectively (P=.93). There was no difference in 24-hour survival among the three groups (91.9%, 94.1% and 92.3%, P=.66).

CONCLUSION

The WCD first-shock success rate and post-event 24-hour survival were high and independent from BMI. TTI was positively correlated with BMI but did not impact early clinical outcome. WCD was safe to all BMI groups and the patient wear time was excellent across all groups.

Influence of body mass index on the prognosis of patients successfully resuscitated from out-of-hospital cardiac arrest treated by therapeutic hypothermia

BACKGROUND

Obesity prevalence has dramatically increased over recent years and is associated with cardiovascular diseases, but data are lacking on its prognostic impact in out-of-hospital cardiac arrest (OHCA) patients.

METHODS

Data of all consecutive OHCA patients admitted in two cardiac arrest centers from Paris and suburbs between 2005 and 2012 were prospectively collected. Patients treated by therapeutic hypothermia (TH) were included in the analysis. Logistic and Cox regression analyses were used to quantify the association between body mass index (BMI) at hospital admission and day-30 and 1-year mortality respectively.

RESULTS

818 patients were included in the study (median age 60.9 [50.8-72.7] year, 70.2% male). Obese patients (BMI>30kgm^-2) were older, more frequently male and evidenced more frequently cardiovascular risk factors than normally (18.5<BMI<25kgm^-2) or overweight patients (25<BMI<30kgm^-2). Post-resuscitation shock and therapeutic hypothermia failure were more frequent in obese patients. Overall mortality at day-30 and one-year was 63.8 and 67.2%, respectively. After multivariate adjustment, BMI>30kgm^-2 was independently associated with day-30 mortality (Odds ratio [OR] in comparison with normally weight patients 2.45; 95% confidence interval [95%CI: 1.32-4.56; p<0.01]). Obesity was not associated with one-year mortality (Hazard ratio [HR] 0.99, 95%CI 0.21,4.67; p=0.99) while underweight was associated with one-year mortality in this subgroup of patients (Hazard ratio [HR] 3.94, 95%CI 1.11,14.01; p=0.03).

CONCLUSION

In the present study, obesity was independently associated with day-30 mortality in successfully resuscitated ICU TH OHCA patients. Further studies are needed to understand the mechanisms that underpin this finding.

Relation of Obesity to Survival After In-Hospital Cardiac Arrest

Previous studies have shown that obesity is paradoxically associated with improved outcomes in many cardiovascular (CV) disease states; however, whether obesity affects survival after in-hospital cardiac arrest (IHCA) has not been well examined. We queried the 2003 to 2011 Nationwide Inpatient Sample databases to identify all patients aged ≥18 years who underwent cardiopulmonary resuscitation for IHCA. Obese patients were identified using the co-morbidity variable for obesity, as defined in Nationwide Inpatient Sample databases. Survival to hospital discharge was compared between obese and nonobese patients using multivariate regression models. Of 836,289 patients with IHCA, 67,216 (8.0%) were obese. Obese patients were younger and more likely to be women compared with nonobese patients. Despite being younger, obese patients had significantly higher prevalence of most CV co-morbidities such as dyslipidemia, coronary artery disease, previous myocardial infarction, heart failure, diabetes mellitus, hypertension, peripheral vascular disease, and chronic renal failure (p <0.001 for all). Obese patients were more likely to have ventricular tachycardia or ventricular fibrillation as the initial cardiac arrest rhythm (22.3% vs 20.9%; p <0.001). After multivariate risk adjustment, obese patients had improved survival to hospital discharge compared with nonobese patients (31.4% vs 24.1%; unadjusted odds ratio 1.44, 95% CI 1.42 to 1.47, p <0.001; adjusted odds ratio 1.15, 95% CI 1.13 to 1.17, p <0.001). Similar results were seen in patients with CV or non-CV conditions as the primary diagnosis and in those with ventricular tachycardia/ventricular fibrillation or pulseless electrical activity/asystole as the cardiac arrest rhythm. In conclusion, this large retrospective analysis of a nationwide cohort of patients with IHCA demonstrated higher risk-adjusted odds of survival in obese patients, consistent with an "obesity paradox."

Sudden cardiac death and obesity

For individuals and the society as a whole, the increased risk of sudden cardiac death in obese patients is becoming a major challenge, especially since obesity prevalence has been increasing steadily around the globe. Traditional risk factors and obesity often coexist. Hypertension, diabetes, obstructive sleep apnea and metabolic syndrome are well-known risk factors for CV disease and are often present in the obese patient. Although the bulk of evidence is circumstantial, sudden cardiac death and obesity share common traditional CV risk factors. Structural, functional and metabolic factors modulate and influence the risk of sudden cardiac death in the obese population. Other risk factors such as left ventricular hypertrophy, increased number of premature ventricular complexes, altered QT interval and reduced heart rate variability are all documented in both obese and sudden cardiac death populations. The present review focuses on out-of-hospital sudden cardiac death and potential mechanisms leading to sudden cardiac death in this population.

Body mass index and survival after in-hospital cardiac arrest

BACKGROUND

The quality and effectiveness of resuscitation processes may be influenced by the patient's body mass index (BMI); however, the relationship between BMI and survival after in-hospital cardiac arrest has not been previously studied.

METHODS AND RESULTS

We evaluated 21 237 adult patients with an in-hospital cardiac arrest within the National Registry for Cardiopulmonary Resuscitation (NRCPR). We examined the association between BMI (classified as underweight [<18.5 kg/m(2)], normal [18.5 to 24.9 kg/m(2)], overweight [25.0 to 29.9 kg/m(2)], obese [30.0 to 34.9 kg/m(2)], and very obese [≥35.0 kg/m(2)]) and survival to hospital discharge using multivariable logistic regression, after stratifying arrests by rhythm type and adjusting for patient characteristics. Of 4499 patients with ventricular fibrillation or pulseless ventricular tachycardia as initial rhythm, 1825 (40.6%) survived to discharge. After multivariable adjustment, compared with overweight patients, underweight (odds ratio [OR], 0.59; 95% confidence interval [CI], 0.41 to 0.84; P=0.003), normal weight (OR, 0.75; 95% CI, 0.63 to 0.89; P<0.001), and very obese (OR, 0.78; 95% CI, 0.63 to 0.96; P=0.02) had lower rates of survival, whereas obese patients had similar rates of survival (OR, 0.87; 95% CI, 0.72 to 1.06; P=0.17). In contrast, of 16 738 patients with arrests caused by asystole or pulseless electric activity, only 2501 (14.9%) survived. After multivariable adjustment, all BMI groups had similar rates of survival except underweight patients (OR, 0.67; 95% CI, 0.54 to 0.82; P<0.001).

CONCLUSIONS

For cardiac arrest caused by shockable rhythms, underweight, normal weight, and very obese patients had lower rates of survival to discharge. In contrast, for cardiac arrest caused by nonshockable rhythms, survival to discharge was similar across BMI groups except for underweight patients. Future studies are needed to clarify the extent to which BMI affects the quality and effectiveness of resuscitation measures.