Joseph P. Condle

Incidence of Rearrest After Return of Spontaneous Circulation in Out-of-Hospital Cardiac Arrest

Abstract Background. Return of spontaneous circulation (ROSC) occurs in 35.0 to 61.0% of emergency medical services (EMS)-treated out-of-hospital cardiac arrests (OHCAs); however, not all patients achieving ROSC survive to hospital arrival or discharge. Previous studies have estimated the incidence of some types of rearrest(RA) at 61.0 to 79.0%, and the electrocardiogram (ECG) waveform characteristics of prehospital RA rhythms have not been previously described. Objectives. We sought to determine the incidence of RA in OHCA, to classify RA events by type, and to measure the time from ROSC to RA. We also conducted a preliminary analysis of the relationship between first EMS-detected rhythms and RA, as well as the effect of RA on survival. Methods. The Pittsburgh Regional Clinical Center of the National Heart, Lung, and Blood Institute (NHLBI) -sponsored Resuscitation Outcomes Consortium (ROC) provided cases from a population-based cardiac arrest surveillance program, ROC Epistry. Only OHCA cases of nontraumatic etiology with available and adequate ECG files were included. We analyzed defibrillator–monitor ECG tracings (Philips MRX), patient care reports (PCRs), and defibrillator audio recordings from EMS-treated cases of OHCA spanning the period from October 2006 to December 2008. We identified ROSC and RA through interpretation of ECG tracings and audio recordings. Rearrest events were categorized as ventricular fibrillation (VF), pulseless ventricular tachycardia (VT), asystole, and pulseless electrical activity (PEA) based on ECG waveform characteristics. Proportions of RA rhythms were stratified by first EMS rhythm and compared using Pearsons chi-square test. Logistic regression was used to test the predictive relationship between RA and survival to hospital discharge. Results. Return of spontaneous circulation occurred in 329 of 1,199 patients (27.4% [95.0% confidence interval (CI): 25.0–30.0%]) treated for cardiac arrest. Of these, 113 had ECG tracings that were available and adequate for analysis. Rearrest occurred in 41 patients (36.0% [95.0% CI: 26.0–46.0%]), with a total of 69 RA events. Survival to hospital discharge in RA cases was 23.1% (95.0% CI: 11.1–39.3%), compared with 27.8% (95.0% CI: 17.9–39.6%) in cases without RA. Counts of RA events by type were as follows: 17 VF (24.6% [95% CI: 15.2–36.5%]), 20 pulseless VT (29.0% [95.0% CI: 18.7–41.2%]), 26 PEA (37.0% [95.0% CI: 26.3–50.2%]), and six asystole (8.8% [95.0% CI: 3.3–18.0%]). Rearrest was not predictive of survival to hospital discharge; however, initial EMS rhythm was predictive of RA shockability. The overall median (interquartile range) time from ROSC to RA among all events was 3.1 (1.6–6.3) minutes. Conclusion. In this sample, the incidence of RA was 38.0%. The most common type of RA was PEA. Shockability of first EMS rhythm was found to predict subsequent RA rhythm shockability.

Documentation discrepancies of time-dependent critical events in out of hospital cardiac arrest

OBJECTIVES The timing of and interval between events in prehospital care is important for system design, patient outcome, and prehospital research. Since these data can guide treatment recommendations, it is imperative that time-based prehospital documentation is accurate and precise, especially for time-sensitive conditions such as out-of-hospital cardiac arrest (OHCA). We compared the times of select events documented in the medical record (PCR) with times from time-stamped audio recordings in the monitor-defibrillator (AUD). METHODS A retrospective cohort of prehospital, adult, atraumatic OHCA resuscitations from two regional EMS agencies over a 10-month period was performed. Primary outcome was absolute difference (minutes) between PCR and AUD documented times for select events during OHCA resuscitation (IV access, IO access, first epinephrine administration, supraglottic airway insertion, endotracheal intubation, and return of spontaneous circulation). We describe the magnitude and direction of differences, and estimate the potential error in time intervals abstracted from the medical record. RESULTS Of 411 patients treated by EMS, 192 had complete data for ≥1 event and 136 had complete data for ≥2 events. 422 total events were identifiable in both PCR and AUD. Median absolute time discrepancy between PCR and AUD was 2 (IQR 1-4) min. Median differences between the smallest and largest PCR-AUD discrepancy was 2 (IQR 1-4.5) min. Discrepancies were both positive and negative, and not consistent within individual records. CONCLUSION We found a 2 (IQR 1-4) min imprecision in the documented timing of select events during OHCA resuscitation. This imprecision contributes to uncertainty in analyses that incorporate time-stamped variables.

A randomized trial of continuous versus interrupted chest compressions in out-of-hospital cardiac arrest: rationale for and design of the Resuscitation Outcomes Consortium Continuous Chest Compressions Trial.

The Resuscitation Outcomes Consortium is conducting a randomized trial comparing survival with hospital discharge after continuous chest compressions without interruption for ventilation versus currently recommended American Heart Association cardiopulmonary resuscitation with interrupted chest compressions in adult patients with out-of-hospital cardiac arrest without obvious trauma or respiratory cause. Emergency medical services perform study cardiopulmonary resuscitation for 3 intervals of manual chest compressions (each ~2 minutes) or until restoration of spontaneous circulation. Patients randomized to the continuous chest compression intervention receive 200 chest compressions with positive pressure ventilations at a rate of 10/min without interruption in compressions. Those randomized to the interrupted chest compression study arm receive chest compressions interrupted for positive pressure ventilations at a compression:ventilation ratio of 30:2. In either group, each interval of compressions is followed by rhythm analysis and defibrillation as required. Insertion of an advanced airway is deferred for the first ≥6 minutes to reduce interruptions in either study arm. The study uses a cluster randomized design with every-6-month crossovers. The primary outcome is survival to hospital discharge. Secondary outcomes are neurologically intact survival and adverse events. A maximum of 23,600 patients (11,800 per group) enrolled during the post-run-in phase of the study will provide ≥90% power to detect a relative change of 16% in the rate of survival to discharge, 8.1% to 9.4% with overall significance level of 0.05. If this trial demonstrates improved survival with either strategy, >3,000 premature deaths from cardiac arrest would be averted annually.

A randomized trial of continuous versus interrupted chest compressions in out-of-hospital cardiac arrest

The Resuscitation Outcomes Consortium is conducting a randomized trial comparing survival with hospital discharge after continuous chest compressions without interruption for ventilation versus currently recommended American Heart Association cardiopulmonary resuscitation with interrupted chest compressions in adult patients with out-of-hospital cardiac arrest without obvious trauma or respiratory cause. Emergency medical services perform study cardiopulmonary resuscitation for 3 intervals of manual chest compressions (each ~2 minutes) or until restoration of spontaneous circulation. Patients randomized to the continuous chest compression intervention receive 200 chest compressions with positive pressure ventilations at a rate of 10/min without interruption in compressions. Those randomized to the interrupted chest compression study arm receive chest compressions interrupted for positive pressure ventilations at a compression:ventilation ratio of 30:2. In either group, each interval of compressions is followed by rhythm analysis and defibrillation as required. Insertion of an advanced airway is deferred for the first ≥6 minutes to reduce interruptions in either study arm. The study uses a cluster randomized design with every-6-month crossovers. The primary outcome is survival to hospital discharge. Secondary outcomes are neurologically intact survival and adverse events. A maximum of 23,600 patients (11,800 per group) enrolled during the post-run-in phase of the study will provide ≥90% power to detect a relative change of 16% in the rate of survival to discharge, 8.1% to 9.4% with overall significance level of 0.05. If this trial demonstrates improved survival with either strategy, >3,000 premature deaths from cardiac arrest would be averted annually.

Effect of Fatigue Training on Safety, Fatigue, and Sleep in Emergency Medical Services Personnel and Other Shift Workers: A Systematic Review and Meta-Analysis

Abstract Background: Fatigue training may be an effective way to mitigate fatigue-related risk. We aimed to critically review and synthesize existing literature on the impact of fatigue training on fatigue-related outcomes for Emergency Medical Services (EMS) personnel and similar shift worker groups. Methods: We performed a systematic literature review for studies that tested the impact of fatigue training of EMS personnel or similar shift workers. Outcomes of interest included personnel safety, patient safety, personnel performance, acute fatigue, indicators of sleep duration and quality, indicators of long-term health (e.g., cardiovascular disease), and burnout/stress. A meta-analysis was performed to determine the impact of fatigue training on sleep quality. Results: Of the 3,817 records initially identified for review, 18 studies were relevant and examined fatigue training in shift workers using an experimental or quasi-experimental design. Fatigue training improved patient safety, personal safety, and ratings of acute fatigue and reduced stress and burnout. A meta-analysis of five studies showed improvement in sleep quality (Fixed Effects SMD −0.87; 95% CI −1.05 to −0.69; p < 0.00001; Random Effects SMD −0.80; 95% CI −1.72, 0.12; p < 0.00001). Conclusions: Reviewed literature indicated that fatigue training improved safety and health outcomes in shift workers. Further research is required to identify the optimal components of fatigue training programs to maximize the beneficial outcomes.

Effects of Napping During Shift Work on Sleepiness and Performance in Emergency Medical Services Personnel and Similar Shift Workers: A Systematic Review and Meta-Analysis

Abstract Background: Scheduled napping during work shifts may be an effective way to mitigate fatigue-related risk. This study aimed to critically review and synthesize existing literature on the impact of scheduled naps on fatigue-related outcomes for EMS personnel and similar shift worker groups. Methods: A systematic literature review was performed of the impact of a scheduled nap during shift work on EMS personnel or similar shift workers. The primary (critical) outcome of interest was EMS personnel safety. Secondary (important) outcomes were patient safety; personnel performance; acute states of fatigue, alertness, and sleepiness; indicators of sleep duration and/or quality; employee retention/turnover; indicators of long-term health; and cost to the system. Meta-analyses were performed to evaluate the impact of napping on a measure of personnel performance (the psychomotor vigilance test [PVT]) and measures of acute fatigue. Results: Of 4,660 unique records identified, 13 experimental studies were determined relevant and summarized. The effect of napping on reaction time measured at the end of shift was small and non-significant (SMD 0.12, 95% CI −0.13 to 0.36; p = 0.34). Napping during work did not change reaction time from the beginning to the end of the shift (SMD −0.01, 95% CI −25.0 to 0.24; p = 0.96). Naps had a moderate, significant effect on sleepiness measured at the end of shift (SMD 0.40, 95% CI 0.09 to 0.72; p = 0.01). The difference in sleepiness from the start to the end of shift was moderate and statistically significant (SMD 0.41, 95% CI 0.09 to 0.72; p = 0.01). Conclusions: Reviewed literature indicated that scheduled naps at work improved performance and decreased fatigue in shift workers. Further research is required to identify the optimal timing and duration of scheduled naps to maximize the beneficial outcomes.

Effect of Task Load Interventions on Fatigue in Emergency Medical Services Personnel and Other Shift Workers: A Systematic Review.

Abstract Background: Modifying the task load of Emergency Medical Services (EMS) personnel may mitigate fatigue, sleep quality and fatigue related risks. A review of the literature addressing task load interventions may benefit EMS administrators as they craft policies related to mitigating fatigue. We conducted a systematic review of the peer-reviewed literature to address the following question: “In EMS personnel, do task load interventions mitigate fatigue, mitigate fatigue-related risks, and/or improve sleep?” (PROSPERO 2016:CRD42016040114). Methods: We performed a systematic review of the literature that described use of randomized controlled trials, quasi-experimental studies, and observational study designs. We retained and reviewed research that involved EMS personnel or similar shift worker groups 18 years of age and older. Studies of ‘healthy volunteers’ and non-shift worker populations were excluded. Studies were included where the methodology of the study implied a theoretical framework of task load (or workload) affecting fatigue, and then fatigue related outcomes. Outcomes of interest included personnel safety, patient safety, personnel performance, acute fatigue, and cost to system. We used the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology to summarize findings and assess quality of evidence from very low to high quality. Results: The search strategy yielded 3,394 unique records resulting in 58 records included as potentially eligible. An additional 69 studies were reviewed in full following searches of bibliographies. We detected wide variation in the description and measurement of task load in the retained and excluded research. Among 127 potentially relevant studies reviewed in full, five were judged eligible. None of the retained studies reported findings germane to personnel safety, patient safety, or cost to system. We judged most studies to have serious or very serious risk of bias. Conclusions: The effect of task load interventions on fatigue, fatigue-related risks, and/or sleep quality was not estimable and the overall quality of evidence was judged low or very low. There was considerable heterogeneity in how task load was defined and measured.

Systematic Review and Meta-analysis of the Effects of Caffeine in Fatigued Shift Workers: Implications for Emergency Medical Services Personnel

Abstract Background: Emergency Medical Services (EMS) workers may experience fatigue as a consequence of shift work. We reviewed the literature to determine the impact of caffeine as a countermeasure to fatigue in EMS personnel and related shift workers. Methods: We employed the GRADE methodology to perform a systematic literature review and search multiple databases for research that examined the impact of caffeine on outcomes of interest, such as patient and EMS personnel safety. For selected outcomes, we performed a meta-analysis of pooled data and reported the pooled effect in the form of a Standardized Mean Difference (SMD) with corresponding 95% confidence intervals. Results: There are no studies that investigate caffeine use and its effects on EMS workers or on patient safety. Four of 8 studies in shift workers showed that caffeine improved psychomotor vigilance, which is important for performance. Caffeine decreased the number of lapses on a standardized test of performance [SMD = 0.75 (95% CI: 0.30 to 1.19), p = 0.001], and lessened the slowing of reaction time at the end of shifts [SMD = 0.52 (95% CI: 0.19 to 0.85); p = 0.002]. Finally, 2 studies reported that caffeine reduced sleep quality and sleep duration. Conclusions: Although the quality of evidence was judged to be low to moderate, when taken together, these studies demonstrate that caffeine can improve psychomotor performance and vigilance. However, caffeine negatively affects sleep quality and sleep duration. More systematic, randomized studies need to be conducted in EMS workers in order to address the critical outcomes of health and safety of EMS personnel and patients. The risk/benefit ratio of chronic caffeine use in shift workers is currently unknown.

Shorter Versus Longer Shift Durations to Mitigate Fatigue and Fatigue-Related Risks in Emergency Medical Services Personnel and Related Shift Workers: A Systematic Review

ABSTRACT Background: This study comprehensively reviewed the literature on the impact of shorter versus longer shifts on critical and important outcomes for Emergency Medical Services (EMS) personnel and related shift worker groups. Methods: Six databases (e.g., PubMed/MEDLINE) were searched, including one website. This search was guided by a research question developed by an expert panel a priori and registered with the PROSPERO database of systematic reviews (2016:CRD42016040099). The critical outcomes of interest were patient safety and personnel safety. The important outcomes of interest were personnel performance, acute fatigue, sleep and sleep quality, retention/turnover, long-term health, burnout/stress, and cost to system. Screeners worked independently and full-text articles were assessed for relevance. Data abstracted from the retained literature were categorized as favorable, unfavorable, mixed/inconclusive, or no impact toward the shorter shift duration. This research characterized the evidence as very low, low, moderate, or high quality according to the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. Results: The searched yielded n = 21,674 records. Of the 480 full-text articles reviewed, 100 reported comparisons of outcomes of interest by shift duration. We identified 24 different shift duration comparisons, most commonly 8 hours versus 12 hours. No one study reported findings for all 9 outcomes. Two studies reported findings linked to both critical outcomes of patient and personnel safety, 34 reported findings for one of two critical outcomes, and 64 did not report findings for critical outcomes. Fifteen studies were grouped to compare shifts <24 hours versus shifts ≥24 hours. None of the findings for the critical outcomes of patient and personnel safety were categorized as unfavorable toward shorter duration shifts (<24 hours). Nine studies were favorable toward shifts <24 hours for at least one of the 7 important outcomes, while findings from one study were categorized as unfavorable. Evidence quality was low or very low. Conclusions: The quality of existing evidence on the impact of shift duration on fatigue and fatigue-related risks is low or very low. Despite these limitations, this systematic review suggests that for outcomes considered critical or important to EMS personnel, shifts <24 hours in duration are more favorable than shifts ≥24 hours.