A randomised crossover comparison of mouth-to-face-shield ventilation and mouth-to-pocket-mask ventilation by surf lifeguards in a manikin

Quality of Cardiopulmonary Resuscitation in Avalanche Victims with a Single Rescuer: A Prospective, Crossover, Manikin Pilot Study

Tanaka, Shota, Koshi Nakagawa, Yosuke Kanagawa, Takashi Katsurahara, Kazuki Kozakai, Ken Tsuhako, Fumitaka Yoshikawa, Soh Gotoh, Kensuke Osanai, Madoka Sono, Hironori Inoue, Shuji Sakanashi, Hiroyuki Takahashi, and Hideharu Tanaka. Quality of cardiopulmonary resuscitation in avalanche victims with a single rescuer: a prospective, crossover, manikin pilot study. High Alt Med Biol. 25:60-67, 2024. Background: Winter outdoor recreational activities such as off-piste skiing have gained popularity and, as a result, the number of avalanche-related deaths has increased. However, the quality of cardiopulmonary resuscitation (CPR) at avalanche sites remains unclear. Our study compared the quality of CPR performed in a simulated avalanche burial on a snowy mountain with that performed indoors. Methods: Ten prehospital health care providers participated in the crossover pilot study. Various methods, including over-the-head CPR (OTH-CPR) and standard CPR, were used to perform avalanche resuscitation, with five rescue breaths, followed by 30 chest compressions and two breaths. The quality CPR was judged by four variables of chest compression and ventilation. Results: The OTH-CPR performed indoors was better in quality: 5.33% [95% confidence interval (CI) -14.2 to 3.5] higher in adequate compression depth (94.3 ± 10.6% on the snow vs. 99.3 ± 1.1% indoors), 3.4% [95% CI -16.1 to 22.9] higher in adequate compression rate (70.4 ± 38.0% vs. 76.1 ± 35.7%), and 2.3% [95% CI -6.4 to 1.72] higher in adequate recoil (96.9 ± 4.8% vs. 99.2 ± 1.6%) than OTH-CPR on the snow. In terms of ventilation quality, OTH-CPR performed indoors had a 50% higher ventilation score [95% CI -73.0 to -27.0] than OTH-CPR on the snow (1.4 ± 4.3% vs. 45.9 ± 32.6%, Cohen's d = -1.81). Conclusions: Chest compression quality was slightly impaired in the avalanche scenarios on the snow than in indoor settings. Asphyxiation is the main cause of avalanche-related deaths; however, low ventilation quality was observed on snow compared with the indoor setting.

Surgical mask-to-mouth ventilation as an alternative ventilation technique during CPR: A crossover randomized controlled trial

INTRODUCTION

Chest compression with rescue breathing improves outcomes in cardiac arrest. However, the efficacy of rescue breathing through surgical masks has not been investigated.

OBJECTIVE

We aimed to compare the tidal volume generated by mouth-to-mouth ventilation (MMV) with that generated by surgical mask-to-mouth ventilation (SMV), mouth-to-surgical mask ventilation (MSV), and surgical mask-to-surgical mask ventilation (SSV) in a manikin.

METHODS

A crossover randomized controlled trial was conducted in 42 medical personnel volunteers randomly assigned to perform four ventilation techniques: MMV (no protective equipment), SMV (participant wearing a mask), MSV (manikin wearing a mask), and SSV, (both participant and manikin wearing a mask). The average tidal volume and the proportion of adequate ventilation, evaluated using a manikin, were compared across different ventilation methods.

RESULTS

The average tidal volume of MMV (828 ± 278 ml) was significantly higher than those of the MSV (648 ± 250 ml, P < 0.001) and SSV (466 ± 301 ml, P < 0.001), but not SMV (744 ± 288 ml, P = 0.054). Adequate ventilation was achieved in 144/168 (85.7%) cases in the MMV group, a proportion significantly higher than in the SMV (77.4%, P = 0.02), MSV (66.7%, P < 0.001) and SSV (39.3%, P < 0.001) groups. The willingness to perform SMV was higher than that to perform MMV.

CONCLUSIONS

MMV resulted in a superior average tidal volume when compared to both MSV and SSV. However, SMV achieved a comparable average tidal volume to MMV.

CPR with restricted patient access using alternative rescuer positions: a randomised cross-over manikin study simulating the CPR scenario after avalanche burial

Background

The aim of this manikin study was to evaluate the quality of cardiopulmonary resuscitation (CPR) with restricted patient access during simulated avalanche rescue using over-the-head and straddle position as compared to standard position.

Methods

In this prospective, randomised cross-over study, 25 medical students (64% male, mean age 24) performed single-rescuer CPR with restricted patient access in over-the-head and straddle position using mouth-to-mouth ventilation or pocket mask ventilation. Chest compression depth, rate, hand position, recoil, compression/decompression ratio, hands-off times, tidal volume of ventilation and gastric insufflation were compared to CPR with unrestricted patient access in standard position.

Results

Only 28% of all tidal volumes conformed to the guidelines (400–800 ml), 59% were below 400 ml and 13% were above 800 ml. There was no significant difference in ventilation parameters when comparing standard to atypical rescuer positions. Participants performed sufficient chest compressions depth in 98.1%, a minimum rate in 94.7%, correct compression recoil in 43.8% and correct hand position in 97.3% with no difference between standard and atypical rescuer positions. In 36.9% hands-off times were longer than 9 s.

Conclusions

Efficacy of CPR from an atypical rescuer position with restricted patient access is comparable to CPR in standard rescuer position. Our data suggest to start basic life-support before complete extrication in order to reduce the duration of untreated cardiac arrest in avalanche rescue. Ventilation quality provided by lay rescuers may be a limiting factor in resuscitation situations where rescue ventilation is considered essential.

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.

Measuring the physiological impact of extreme heat on lifeguards during cardiopulmonary resuscitation. Randomized simulation study

OBJECTIVE

Lifeguard teams carry out their work in extremely hot conditions in many parts of the world. The aim of this study was to analyze the impact of high temperatures on physiological parameters during cardiopulmonary resuscitation (CPR).

METHOD

A randomized quasi-experimental cross-over design was used to test physiological lifesaving demands (50 min acclimatization +10 min CPR) in two different thermal environments: Thermo-neutral environment (25 °C) vs Hyperthermic environment (37 °C).

RESULTS

The data obtained from 21 lifeguards were included, this covers a total of 420 min of resuscitation. The CPR performance was constantly maintained during the 10 min. The Oxygen uptake (VO 2) ranged from 17 to 18 ml/min/kg for chest compressions (CC) and between 13 and 14 ml/min/kg for ventilations (V) at both 25 °C and 37 °C, with no significant difference between environments (p > 0.05). The percentage of maximum heart rate (%HR max) increased between 7% and 8% at 37 °C (p < 0.001), ranging between 75% and 82% of HR max. The loss of body fluids (LBF) was higher in the hyperthermic environment; LBF: (37 °C: 400 ± 187 g vs 25 °C: 148 ± 81 g, p < 0.001). Body temperature was 1 °C higher at the end of the test (p < 0.001). The perceived fatigue (RPE) increased by 37° an average of 2 points on a scale of 10 (p = 0.001).

CONCLUSIONS

Extreme heat is not a limiting factor in CPR performance with two lifeguards. Metabolic consumption is sustained, with an increase in CC, so V can serve as active rest. Nevertheless, resuscitation at 37 °C results in a higher HR, is more exhausting and causes significant loss of fluids due to sweating.

Comparing Surf Lifeguards and Nurse Anesthetists' Use of the i-gel Supraglottic Airway Device - An Observational Simulation Study

Purpose

Using a supraglottic airway (SGA) may provide more effective ventilations compared with a mouth-to-pocket-mask for drowning victims. SGAs are widely used by nurse anesthetists but it is unknown whether surf lifeguards can use SGAs effectively. We aimed to compare the use of SGA by surf lifeguards and experienced nurse anesthetists.

Materials and Methods

Surf lifeguards inserted a SGA (i-gel O₂, size 4) in a resuscitation manikin during cardiopulmonary resuscitation (CPR) and nurse anesthetists inserted a SGA in a resuscitation manikin placed on a bed, and performed ventilations. Outcome measures: time to first ventilation, tidal volume, proportion of ventilations with visible manikin chest rise, and ventilations within the recommended tidal volume (0.5–0.6 L).

Results

Overall, 30 surf lifeguards and 30 nurse anesthetists participated. Median (Q1–Q3) time to first ventilation was 20 s (15–22) for surf lifeguards and 17 s (15–21) for nurse anesthetists (p=0.31). Mean (SD) tidal volume was 0.55 L (0.21) for surf lifeguards and 0.31 L (0.10) for nurse anesthetists (p<0.0001). Surf lifeguards and nurse anesthetists delivered 100% and 95% ventilations with visible manikin chest rise (p=0.004) and 19% and 5% ventilations within the recommended tidal volume, respectively (p<0.0001).

Conclusion

In a simulated setting, there was no significant difference between surf lifeguards and experienced nurse anesthetists in time to first ventilation when using a SGA. Surf lifeguards delivered a higher tidal volume, and a higher proportion of ventilations within guideline recommendations, but generally ventilations caused visible manikin chest rise for both groups.

Evaluation of a Multimodal Resuscitation Program and Comparison of Mouth-to-Mouth and Bag-Mask Ventilation by Relatives of Children With Chronic Diseases

OBJECTIVES

Children with chronic critical illness are at higher risk for cardiopulmonary arrests. Before chronically ill children are discharged from hospital, family members receive training in basic life support at many institutions. We evaluated whether a multimodal training program is able to teach adherence to current resuscitation guidelines and whether laypersons can be trained to perform both bag-mask ventilation and mouth-to-mouth ventilation equally effective in infants.

DESIGN

Prospective observational study.

SETTING

Pediatric critical care unit of a tertiary referral center.

SUBJECTS

Relatives of children with chronic illness prior to discharge from hospital.

INTERVENTIONS

Multimodal emergency and cardiopulmonary resuscitation training program.

MEASUREMENTS AND MAIN RESULTS

Following participation in our cardiopulmonary resuscitation training program 56 participants performed 112 simulated cardiopulmonary resuscitations (56 with mouth-to-mouth ventilation, 56 with bag-mask ventilation). Nearly all participants checked for consciousness and breathing. Shouting for help and activation of the emergency response system was only performed in half of the cases. There was almost full adherence to the resuscitation guidelines regarding number of chest compressions, chest compression rate, compression depth, full chest recoil, and duration of interruption of chest compression for rescue breaths. The comparison of mouth-to-mouth ventilation and bag-mask ventilation revealed no significant differences regarding the rate of successful ventilation (mouth-to-mouth ventilation: 77.1% ± 39.6%, bag-mask ventilation: 80.4% ± 38.0%; p = 0.39) and the cardiopulmonary resuscitation performance.

CONCLUSIONS

A standardized multimodal cardiopulmonary resuscitation training program for family members of chronically ill children is effective to teach good cardiopulmonary resuscitation performance and adherence to resuscitation guidelines. Laypersons could be successfully trained to equally perform mouth-to-mouth and bag-mask ventilation technique.

[Ventilation during cardiopulmonary resuscitation in the infant. Mouth to mouth and nose, or bag-valve-mask? A quasi-experimental study]

INTRODUCTION

It has been observed that health professionals have difficulty performing quality cardiopulmonary resuscitation (CPR). The aim of this study was to compare the quality of ventilations performed by Nursing students on an infant model using different methods (mouth-to-mouth-and-nose or bag-valve-mask).

MATERIAL AND METHODS

A quasi-experimental cross-sectional study was performed that included 46 second-year Nursing students. Two quantitative 4-minute tests of paediatric CPR were performed: a) mouth-to-mouth-and-nose ventilations, and b) ventilations with bag-valve-mask. A Resusci Baby QCPR Wireless SkillReporter® mannequin from Laerdal was used. The proportion of ventilations with adequate, excessive, and insufficient volume was recorded and analysed, as well as the overall quality of the CPR (ventilations and chest compressions).

RESULTS

The students were able to give a higher number of ventilations with adequate volume using the mouth-to-mouth-and-nose method (55±22%) than with the bag-valve-mask (28±16%, P<.001). The overall quality of the CPR was also significantly higher when using the mouth-to-mouth-and-nose method (60±19 vs. 48±16%, P<.001).

CONCLUSIONS

Mouth-to-mouth-and-nose ventilation method is more efficient than bag-valve-mask ventilations in CPR performed by nursing students with a simulated infant model.

Can surf-lifeguards perform a quality cardiopulmonary resuscitation sailing on a lifeboat? A quasi-experimental study

PURPOSE

Drowning is a high-priority public health problem around the world. The European Resuscitation Council Guidelines for Resuscitation 2015 put special emphasis on special environments like open waters. Stopping the drowning process as soon as possible and starting an early cardiopulmonary resuscitation (CPR) improve survival. Inflatable rescue boats (IRBs) are used around the world in the water rescue of drowning victims. Our objective was to test the quality of CPR performed by surf-lifeguards while sailing on an IRB.

METHODS

A quasi-experimental simulation trial was conducted in Tenerife (Canary Islands-Spain) on September 2015. Ten surf-lifeguards were asked to perform a 2 min CPR on manikins in four different scenarios: (1) onshore, (2) on adrift boat, (3) on a boat sailing at 5 knots and (4) on a boat sailing at 10 knots. CPR was performed individually and was measured by means of CPRmeter (Laerdal, Norway) located on the standard manikin. Repeated measures analysis of variance was used in order to analyse the differences between scenarios.

RESULTS

The composite of all CPR variables was over 84% in all conditions, but it was lower when CPR was performed on board: onshore (96.49±3.58%) versus adrift (91.80±3.56, p=0.04), sailing at 5 knots (88.65±5.54, p=0.03) and sailing at 10 knots (84.74±5.56, p=0.001).

CONCLUSION

Surf-lifeguards are able to deliver good-quality CPR even on a moving IRB, but their performance is lower than onshore. This fact should be considered in real cases to balance the risk and benefits of CPR on board.