LUCAS Device Use Associated with Prolonged Pauses during Application and Long Chest Compression Intervals.

BACKGROUND: Tenets of high-quality out-of-hospital cardiac arrest (OHCA) resuscitation include early recognition and treatment of shockable rhythms, and minimizing interruptions in compressions. Little is known about how use of a mechanical compression device affects these elements. We hypothesize that use of such a device is associated with prolonged pauses in compressions to apply the device, and long compression intervals overall. METHODS: We systematically abstracted CPR metrics from 4 months of adult non-traumatic OHCA cases, each of which had at least 10 minutes of resuscitation, used a LUCAS device, and had a valid monitor file attached to the patient care report. Our primary outcomes of interest were the duration of each pause in compressions and the duration of compressions between pauses, stratified by whether or not the LUCAS device was used/applied during the segment. Each pause was further evaluated for a possible associated procedure based on pre-defined criteria. Descriptive statistics, chi-square, and Kruskal-Wallis tests were used as appropriate. RESULTS: Fifty-eight cases were included, median age 62.5 years (IQR 49.3-70.8), 47% female, 66% nonwhite. Overall, 633 compression-pause segments were analyzed (517 with and 116 without LUCAS applied). Spacing of pauses was significantly longer with the LUCAS than without [median (IQR) 133 (82-213) seconds vs. 38 (18-62) seconds, p < 0.05]. When using a LUCAS, compressions were continuous for at least 3 min in 166/517 segments, at least 4 min in 89/517 segments, and at least 5 min in 56/517 segments. Without a LUCAS, compressions were longer than 3 min in 7/116 segments. Pauses exceeded 10 s more frequently with LUCAS application (32/38) than airway management or defibrillation (27/80, p < 0.05). Peri-LUCAS pauses exceeded 30 s in 6/38 cases. CONCLUSION: LUCAS use was associated with long compression intervals without identifiable pauses to assess for pulse or cardiac rhythm, and device application was associated with longer pauses than airway management or defibrillation. The clinical significance and effect on patient outcomes remain uncertain and require further study.

Ventilation rates measured by capnography during out-of-hospital cardiac arrest resuscitations and their association with return of spontaneous circulation.

BACKGROUND: Clinical guidelines for adult out-of-hospital cardiac arrest (OHCA) recommend a ventilation rate of 8-10 per minute yet acknowledge that few data exist to guide recommendations. The goal of this study was to evaluate the utility of continuous capnography to measure ventilation rates and the association with return of spontaneous circulation (ROSC). METHODS: This was a retrospective observational cohort study. We included all OHCA during a two-year period and excluded traumatic and pediatric patients. Ventilations were recorded using non-invasive continuous capnography. Blinded medically trained team members manually annotated all ventilations. Four techniques were used to analyze ventilation rate. The primary outcome was sustained prehospital ROSC. Secondary outcomes were vital status at the end of prehospital care and survival to hospital admission. Univariable and multivariable logistic regression models were constructed. RESULTS: A total of 790 OHCA were analyzed. Only 386 (49%) had useable capnography data. After applying inclusion and exclusion criteria, the final study cohort was 314 patients. The median ventilation rate per minute was 7 (IQR 5.4-8.5). Only 70 (22%) received a guideline-compliant ventilation rate of 8-10 per minute. Sixty-two (20%) achieved the primary outcome. No statistically significant associations were observed between any of the ventilation parameters and patient outcomes in both univariable and multivariable logistic regression models. CONCLUSIONS: We failed to detect an association between intra-arrest ventilation rates measured by continuous capnography and proximal patient outcomes after OHCA. Capnography has poor reliability as a measure of ventilation rate. Achieving guideline-compliant ventilation rates remains challenging.