Physiological demands of quality cardiopulmonary resuscitation performed at simulated 3250 meters high

Feasibility of Mouth-to-Mouth Ventilation through FPP2 Respirator in BLS Training during COVID-19 Pandemic (MOVERESP Study): Simulation-Based Study

Background: Due to the COVID-19 pandemic, Basic Life Support (BLS) training has been limited to compression-only or bag–mask ventilation. The most breathable nanofiber respirators carry the technical possibility for inflation of the mannequin. The aim of this study was to assess the efficacy of mouth-to-mouth breathing through a FFP2 respirator during BLS. Methods: In the cross-over simulation-based study, the medical students performed BLS using a breathable nanofiber respirator for 2 min on three mannequins. The quantitative and qualitative efficacy of mouth-to-mouth ventilation through the respirator in BLS training was analyzed. The primary aim was the effectivity of mouth-to-mouth ventilation through a breathable respirator. The secondary aims were mean pause, longest pause, success in achieving the optimal breath volume, technique of ventilation, and incidence of adverse events. Results: In 104 students, effective breath was reached in 951 of 981 (96.9%) attempts in Adult BLS mannequin (Prestan), 822 of 906 (90.7%) in Resusci Anne, and 1777 of 1857 (95.7%) in Resusci Baby. In Resusci Anne and Resusci Baby, 28.9%/15.9% of visible chest rises were evaluated as low-, 33.0%/44.0% as optimal-, and 28.8%/35.8% as high-volume breaths. Conclusions: Mouth-to-mouth ventilation through a breathable respirator had an effectivity greater than 90%.

Analysis of Physiological Response during Cardiopulmonary Resuscitation with Personal Protective Equipment: A Randomized Crossover Study

The use of personal protective equipment (PPE) is required for the self-protection of healthcare workers during cardiopulmonary resuscitation (CPR) in patients at risk of aerosol transmission of infectious agents. The aim of this study was to analyze the impact of personal protective equipment on physiological parameters during CPR. A randomized, quasi-experimental, crossover design was used. The study was carried out in a training and simulation emergency box and the total sample consisted of 20 healthcare professionals. Two CPR tests were compared with the recommended sequence of 30 chest compressions and 2 ventilations. The duration of each test was 20 min. One of the CPR tests was carried out without using any PPE (CPR_control), i.e., performed with the usual clothing of each rescuer. The other test was carried out using a CPR test with PPE (i.e., CPR_PPE). The main variables of interest were: CPR quality, compressions, ventilations, maximum heart rate, body fluid loss, body temperature, perceived exertion index, comfort, thermal sensation and sweating. The quality of the CPR was similar in both tests. The maximum heart rate was higher in the active intervals (compressions + bag-valve-mask) of the test with PPE. CPR_PPE meant an increase in the perceived effort, temperature at the start of the thermal sensation test, thermal comfort and sweating, as opposed to CPR performed with usual clothing. Performing prolonged resuscitation with PPE did not influence CPR quality, but caused significant physiological demands. Rescuers were more fatigued, sweated more and their thermal comfort was worse. These results suggest that physical preparation should be taken into account when using PPE and protocols for physiological recovery after use should also be established.

Chest Compression Duration May Be Improved When Rescuers Breathe Supplemental Oxygen

BACKGROUND: At sea level, performing chest compressions is a demanding physical exercise. On a commercial flight at cruise altitude, the barometric pressure in the cabin is approximately equal to an altitude of 2438 m. This results in a Po₂ equivalent to breathing an F_Io₂ of 15% at sea level, a condition under which both the duration and quality of cardiopulmonary resuscitation (CPR) may deteriorate. We hypothesized that rescuers will be able to perform fewer rounds of high-quality CPR at an F_Io₂ of 15%.METHODS: In this crossover simulation trial, 16 healthy volunteers participated in 2 separate sessions and performed up to 14 2-min rounds of chest compressions at an F_Io₂ of either 0.15 or 0.21 in randomized order. Subjects were stopped if their S_po₂ was below 80%, if chest compression rate or depth was not achieved for 2/3 of compressions, or if they felt fatigued or dyspneic.RESULTS: Fewer rounds of chest compressions were successfully completed in the hypoxic than in the normoxic condition, (median [IQR] 4.5 [3,8.5]) vs. 5 [4,14]). The decline in arterial S_po₂ while performing chest compressions was greater in the hypoxic condition than in the normoxic condition [mean (SD), 6.19% (4.1) vs. 2% (1.66)].DISCUSSION: Our findings suggest that the ability of rescuers to perform chest compressions in a commercial airline cabin at cruising altitude may be limited due to hypoxia. One possible solution is supplemental oxygen for rescuers who perform chest compressions for in-flight cardiac arrest.Clebone A, Reis K, Tung A, OConnor M, Ruskin KJ. Chest compression duration may be improved when rescuers breathe supplemental oxygen. Aerosp Med Hum Perform. 2020; 91(12):918922.