Effect of physical fatigue on the quality CPR: a water rescue study of lifeguards: physical fatigue and quality CPR in a water rescue

Increasing ventilation in drowning resuscitation - A cross-over randomized simulation study of ventilation during automated external defibrillator analysis pauses

Objective

The aim of this study was to analyze the feasibility of a new resuscitation strategy in which breaths are provided during automated external defibrillator (AED) rhythm analysis, and to evaluate its impact on chest compressions (CC) quality and the peri-analysis time.

Method

A randomized simulation study, comparing two cardiopulmonary resuscitations strategies, has been conducted: the standard strategy (S1) with strategy involving ventilation during AED analysis (S2). Thirty lifeguards have performed both strategies in a cross-over study design during 10 min of CPR.

Results

The number of ventilations per 10 min increases from 47 (S1) to 72 (S2) (p < 0.001). This results in the delivery of an additional 17.1 L of insufflated air in S2 compared to S1 (p < 0.001). There have been no significant changes in frequency and total number of CC. These findings correspond to a reduction of the non-ventilation period from 176 s (S1) to 48 s (S2).

Conclusions

This simulation study suggests that it is feasible to increase the number of ventilations during resuscitation following drowning, without affecting the quantity and quality of chest compressions. The results of this study may serve as a foundation for further investigation into optimal ventilation strategies in this context.

How Does Rescuer's Position Setting Impact Quality of Chest Compression: A Randomized Crossover Simulation Study on Unexperienced Clinicians

Background

High-quality chest compression (CC) is the crux of survival for cardiac arrest patients. While, rescuers' position setting relative to patients during CC was unrecommended in the present guidelines. We aimed to assess the impact of position settings on CC quality during cardiopulmonary resuscitation (CPR) and to test the heterogeneity related to rescuers' characteristics.

Methods

We conducted randomized, crossover, simulation trials with clinical students unfamiliar with CPR. The participants received standard training on performing CC and were divided randomly into two groups. The two groups separately performed CC with standing and kneeling positions in turn, forming the crossover design. The trials were performed with standard manikin models. CC quality indicator data were recorded by the tracking and feedback system automatically.

Result

156 participants finished at least one round of trial, with 126 participants finishing both rounds. Records for CC with kneeling and standing positions showed statistically significant differences in the correct rate, pause happening, average depth, and happening of over-depth compression. Regression analysis also implied that larger compression depths with the standing position were related to larger height and BMI of the participants.

Conclusion

When performing CC, the standing position will lead to lower CC quality by larger chance of pause happening and over-depth compression. In addition, compression depth gaps between CC with kneeling and standing position were related with rescuer characteristics including height and BMI, with a threshold effect.

Is It Feasible to Perform Infant CPR during Transfer on a Stretcher until Cannulation for Extracorporeal CPR? A Randomization Simulation Study

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) improves infant survival outcomes after cardiac arrest. If not feasible at the place of arrest, victims must be transported to a suitable room to perform ECMO while effective, sustained resuscitation maneuvers are performed. The objective of this simulation study was to compare the quality of resuscitation maneuvers on an infant manikin during simulated transfer on a stretcher (stretcher test) within a hospital versus standard stationary resuscitation maneuvers (control test).

METHODS

A total of 26 nursing students participated in a randomized crossover study. In pairs, the rescuers performed two 2 min tests, consisting of five rescue breaths followed by cycles of 15 compressions and two breaths. The analysis focused on CPR variables (chest compression and ventilation), CPR quality, the rate of perceived exertion and the distance covered.

RESULTS

No differences were observed in the chest compression quality variable (82 ± 10% versus 84 ± 11%, p = 0.15). However, significantly worse values were observed in the test for ventilation quality on the stretcher (18 ± 14%) compared to the control test (28 ± 21%), with a value of p = 0.030. Therefore, the overall CPR quality was worse in the stretcher test (50 ± 9%) than in the control test (56 ± 13%) (p = 0.025).

CONCLUSIONS

Infant CPR performed by nursing students while walking alongside a moving stretcher is possible. However, in this model, the global CPR quality is less due to the low ventilation quality.

Assessing student paramedics' measurements of fatigue and quality of cardiopulmonary resuscitation on a simulated cardiac arrest case

OBJECTIVE

The International Liaison Committee on Resuscitation (ILCOR) and the Australian Resuscitation Council (ARC) recommend that high-quality cardiopulmonary resuscitation (CPR) is the key to performance outcomes, emphasising compression and rotation through this process. The proposed study has a two-stage approach to evaluating cardiopulmonary resuscitations effectiveness by out-of-hospital practitioners. The first stage aimed to evaluate the influence of providing real-time biofeedback using the Q-CPR system on the provision of CPR by student paramedics. Secondly, the study quantified the effects of physical fatigue on maintaining quality cardiopulmonary resuscitation performed by paramedic students.

METHODS

Forty paramedic students completed cardiopulmonary resuscitation on an instrumented manikin with and without audio-visual biofeedback (Q-CPR within the Phillips MRx defibrillator) in a balanced cross-over fashion. To quantify the quality of cardiopulmonary resuscitation concerning the percentage of applied compressions that meet the current ARC guidelines in terms of rate, depth, and recoil time, a manikin feedback system (SimMan 3 G; Laerdal, Norwegian) was used.

RESULTS

When using the Q-CPR prompt with bio-feedback, overall, the depth and fatigue levels increased significantly, highlighting a correlation between correct depth and increased fatigue.

CONCLUSIONS

Audio prompts improved compression depth; however, fatigue levels increased. The depth during manual compression compared to the Q-CPR prompt was not statistically significant.

Association of Training in Basic Life Support with the Evolution of Cardiopulmonary Resuscitation Performed by Firefighters

Introduction

This study aimed to compare the results of professional technical and anthropometric anamnesis data with the transmission of external chest compressions performed by military firefighters at different execution times.

Objective

The objective was to evaluate the performance and perceived effort of the sequence of external chest compressions performed in two minutes, as well as the evolution of the technique over time.

Materials and Methods

This was a descriptive, correlational study involving adult firefighters who were members of a specific firefighter group, comprising a population of 105 individuals with a voluntary sample of 44 participants. The study used a Bayesian statistical approach to provide probabilistic expressions.

Results

The participants had an average work experience of 17 years, an average age of 38.6 years, an average weight of 81.48 kilograms, an average height of 176 centimeters, and an average of 2.5 qualifications. The results indicated that the firefighters performed external chest compressions with excellent technique and a moderate level of perceived effort in a two-minute evaluation. The evaluation of the evolution of the technique over time showed that the participants were able to maintain high-quality compressions for an average of 6 minutes, with a maximum of 20 uninterrupted minutes.

Conclusion

The study underscores the critical role of professional firefighters in performing and maintaining high-quality external chest compressions, which has the potential to reduce morbidity and mortality in cases of cardiorespiratory arrest.

Why Percussive Massage Therapy Does Not Improve Recovery after a Water Rescue? A Preliminary Study with Lifeguards

The aim of this study was to analyze the effects of percussive massage therapy (PMT) on lifeguards’ recovery after a water rescue, in comparison with passive recovery. Methods: A quasi-experimental crossover design was conducted to compare passive recovery (PR) and a PMT protocol. A total of 14 volunteer lifeguards performed a simulated 100 m water rescue and perceived fatigue and blood lactate were measured as recovery variables after the rescue and after the 8-min recovery process. Results: There were no differences between PMT and PR in lactate clearance (p > 0.05), finding in both modalities a small but not significant decrease in blood lactate. In perceived fatigue, both methods decreased this variable significantly (p < 0.001), with no significant differences between them (p > 0.05). Conclusions: PMT does not enhance recovery after a water rescue, in comparison with staying passive. Despite PMT appearing to be adequate for recovery in other efforts, it is not recommended for lifeguards’ recovery after a water rescue.

Relationship between psychological characteristics, personality traits, and training on performance in a neonatal resuscitation scenario: A machine learning based analysis

BACKGROUND

In life-threatening emergency events, prompt decision-making and accurate reactions are essential for saving a human's life. Some of these skills can be improved by regular simulation trainings. However, besides these factors, individual characteristics may play a significant role in the patients' outcome after a resuscitation event. This study aimed to differentiate personality characteristics of team members who take responsibility for their actions, contextualizing the effect of training on resuscitation performance.

METHODS

Six hundred and two third-year medical students were asked to answer psychological and personality questionnaires. Fifty-five of them performed in a neonatal simulation resuscitation scenario. To assess participants' performances in the NLS scenario, we used a scenario-based designed NLS checklist. A machine learning design was utilized to better understand the interaction of psychological characteristics and training. The first model aimed to understand how to differentiate between people who take responsibility for their actions vs. those who do not. In a second model, the goal was to understand the relevance of training by contextualizing the effect of training to other important psychological and personality characteristics like locus of control, anxiety, emotion regulation, openness to experience, conscientiousness, extraversion, agreeableness, and neuroticism.

RESULTS

No statistically significant differences were found for psychological characteristics between the training group and the no training group. However, as expected, differences were noted in favor of the training group for performance and within gender for psychological characteristics. When correcting for all these information in a model, anxiety and gender were the most important factors associated with taking responsibility for an action, while training was the only relevant factor in explaining performance during a neonatal resuscitation scenario.

CONCLUSION

Training had a significantly stronger effect on performance in medical students in a neonatal resuscitation scenario than individual characteristics such as demographics, personality, and trait anxiety.

Performance of Basic Life Support by Lifeboat Crewmembers While Wearing a Survival Suit and Life Vest: A Randomized Controlled Trial

Introduction: Crewmembers of the “Royal Netherlands Sea Rescue Institution” (KNRM) lifeboats must wear heavy survival suits with integrated lifejackets. This and the challenging environment onboard (boat movements, limited space) might influence Basic Life Support (BLS) performance. The primary objective of this study was to assess the impact of the protective gear on single-rescuer BLS-quality.

Material and Methods: Sixty-five active KNRM crewmembers who had recently undergone a BLS-refresher course were randomized to wear either their protective gear (n = 32) or their civilian clothes (n = 33; control group) and performed five 2-min sessions of single rescuer BLS on a mannequin on dry land. BLS-quality was assessed according to Dutch and European Resuscitation guidelines. A between group analysis (Mann-Whitney U) and a repeated within group analysis of both groups (Friedman test) were performed.

Results: There were no major demographic differences between the groups. The protective gear did not significant impair BLS-quality. It was also not associated with a significant increase in the perceived exertion of BLS (Borg's Rating scale). Compression depth, compression frequency, the percentage of correct compression depth and of not leaning on the thorax, and ventilation volumes in both groups were suboptimal when evaluated according to the BLS-guidelines.

Conclusions: The protective gear worn by KNRM lifeboat-crewmembers does not have a significant influence on BLS-quality under controlled study conditions. The impact and significance on outcome in real life situations needs to be studied further. This study provides valuable input for optimizing the BLS-skills of lifeboat crewmembers.

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.

Does a short intervention with vibration foam roller recover lifeguards better after a water rescue? A pilot study

PURPOSE

The aim of this study was to analyze the effects of a recovery program based on foam roller with and without vibration on blood lactate clearance and perceived fatigue after a water rescue.

METHODS

A quasi-experimental crossover design was carried out to compare passive (PR) recovery and a short protocol of foam roller (FR) and vibration foam roller (VFR) recovery after a 100 m water rescue in 7 volunteer lifeguards. Blood lactate and perceived exertion were measured before and after the rescue, and also after the 5-min recovery intervention.

RESULTS

Blood lactate levels decrease significantly with foam roller (p = 0.013; effect size = 0.97) and vibration foam roller recovery (p < 0.001; effect size = 1.62). Passive recovery did not show significant differences clearing out blood lactate. Fatigue perceived decrease significantly with all the recovery methods, but foam roller has higher effects on the global fatigue and VFR on the legs.

CONCLUSION

FR and VFR clear out more blood lactate and decrease fatigue more than PR, with the subsequently increase of the physical conditioning to perform another effort.

Mapping Trends in Drowning Research: A Bibliometric Analysis 1995-2020

Drowning is public health issue requiring global, national and community responses. The multisectoral nature of drowning prevention reinforces the need for multidisciplinary research, which can play a key role in identifying patterns, factors and interventions and contributes to evidence-informed prevention. This study presents a biometric analysis of drowning research published in 1995–2020 and identifies temporal trends in research themes, journals, countries and authorship to assist in the planning of future research. This study identified 935 studies, representing authors from 80 countries. Publications grew 103-fold, and 41.2% (n = 385) were published since 2014. The top 20 journals are all injury prevention, public health, or medical journals. The top 5 accounted for 24.5% (n = 229) of total publications (TP). Research from the United States (TP = 313, 25.0%) and Australia (TP = 192, 15.3%) dominates the field. Growth is highest in low–middle-income countries (LMICs) including China (TP = 54, 4.3%, 32-fold), India (TP = 30, 2.4%, 17-fold) and Bangladesh (TP = 47, 3.7%, 7-fold). The study identifies significant growth in epidemiologic studies reporting burden and risk factors. Research in LMICs is increasing but lags relative to the burden. The role of multilateral and nongovernment organisations in evidence generation is evident and needs investigation, as do gaps in evidence for interventions and partnerships to progress the drowning prevention field.

Relationship between the Performance in a Maximum Effort Test for Lifeguards and the Time Spent in a Water Rescue

The main objective of this study was to analyse the relationship between the performance in a maximum incremental test for lifeguards, the IPTL, and the effectiveness of a 200 m water rescue on the beach. Initially, 20 professional lifeguards carried out the IPTL in the pool and then they performed a 200 m water rescue on the beach. The maximum oxygen uptake (VO_2max) in the IPTL was estimated. In both tests, heart rate (HR), blood lactate (La) and time achieved were measured. The VO_2max estimated in the IPTL (VO_2IPTL) was 44.2 ± 4.7 mL·kg·min⁻¹, the time reached in the IPTL (Time_IPTL) was 726 ± 72 s and the time spent in the rescue (Time_Rescue) was 222 ± 14 s. The results showed that the time reached in the pool (Time_IPTL) was the best predictor variable of the performance in water rescue (Time_Rescue) (R² = 0.59; p < 0.01). A significant correlation was also observed between the estimated maximum oxygen uptake and the beach rescue performance (R² = 0.37; p = 0.05). These results reveal that the IPTL, a maximum incremental test specific to lifeguards, allows the estimation of the effectiveness of a 200 m rescue on the beach.

The feasibility of emergency medical technicians performing intermittent high-quality cardiopulmonary resuscitation

Background: Whether intermittent chest compressions have an effect on the quality of CPR is worthy of discussion. The purpose of this study was to investigate differences in the chest compression quality of emergency medical technicians (EMTs) performing cardiopulmonary resuscitation (CPR) with different rest intervals. Methods: Seventy male firefighters with EMT licenses participated in this study. Participants completed body composition measurements and three CPR quality tests, as follows: (1) CPR-uninterrupted for 10 minutes; (2) after 2 days of rest, CPR 10s-intermittent (CPR-10s), for 2 minutes each time and 5 cycles; (3) after another 2 days of rest, CPR 20s-intermittent (CPR-20s), for 2 minutes each time and 5 cycles. Results: Body composition results showed that body mass (BM), body mass index (BMI), upper limb muscle mass (ULMM), core muscle mass (CMM), and upper limb-core muscle mass (UL+CMM) were positively correlated with chest compression depth (CCD) (p < 0.05). Analysis of the three different modes of CPR quality analysis indicated significant differences in the chest compression fraction (CCF, F = 6.801, p = 0.001), chest compression rebound rate (CCRR, F = 3.919, p = 0.021), and ratings of perceived exertion (RPE, F = 23.815, p < 0.001). Among the different performance cycles of CPR-10s, significant differences were found in CCF, CCD, CCR (chest compression rate), and RPE (p < 0.05). On the other hand, among the different performance cycles of CPR-20s, significant differences were found in CCD, CCR, and RPE (p < 0.05). Moreover, the CCF, CCD, and RPE scores of the two tests reached significant differences in specific phases (p < 0.05). Conclusions: This study confirmed that the upper limb muscle mass or the weight of the upper body of EMTs is positively correlated with the quality of CPR. In addition, intermittent chest compressions with safe interruption intervals can reduce fatigue caused by long-term chest compressions and maintain better chest compression quality.

Physiological Response of Quality Cardiopulmonary Resuscitation, Crossover Trial on Mannequin in Extreme Temperature Conditions

BACKGROUND

To determine the relationship between physiological fatigue and the quality of cardiopulmonary resuscitation (CPR) in trained resuscitators in hostile thermal environments (extreme cold and heat) simulating the different conditions found in an out-of-hospital cardiorespiratory arrest.

METHODS

Prospective observational study involving 60 students of the health sciences with training in resuscitation, who simulated CPR on a mannequin for 10 min in different thermal environments: thermo-neutral environment (21 °C and 60% humidity), heat environment (41 °C and 98% humidity) and cold environment (-35 °C and 80% humidity). Physiological parameters (heart rate and lactic acid) and CPR quality were monitored.

RESULTS

We detected a significant increase in the number of compressions per minute in the "heat environment" group after three minutes and in the mean rate after one minute. We observed a negative correlation between the total number of compressions and mean rate with respect to mean depth. The fraction of compressions (proportion of time in which chest compressions are carried out) was significant over time and the mean rate was higher in the "heat environment". Physiological parameters revealed no differences in heart rate depending on the resuscitation scenario; however, there was a greater and faster increase in lactate in the "heat environment" (significant at minute 3). The total proportion of participants reaching metabolic fatigue was also higher in the "heat environment".

CONCLUSIONS

A warm climate modifies metabolic parameters, reducing the quality of the CPR maneuver.

Assessing the quality of CPR performed by a single lifeguard, two lifeguards and a lifeguard with a bystander after water rescue: a quasi-experimental trial

BACKGROUND

High-quality cardiopulmonary resuscitation (CPR) could improve survival of drowning victims. The purpose of the study is to assess the impact of fatigue caused by water rescue on subsequent CPR quality and the influence of a bystander's participation on CPR quality in a lifeguard rescue.

METHODS

This was a simulated quasi-experimental study with a sample of 14 lifeguards and 13 laypersons. Each lifeguard performed 2 min single-rescuer CPR as baseline measurement. In three separate trials, a single lifeguard swam 50 m to perform a water rescue in a pool and returned with the manikin another 50 m. After each rescue, 10 min of CPR was performed by a single lifeguard, two lifeguards or a lifeguard with a layperson with no CPR training. Paired t-test and repeated analysis of variance were used to analyse CPR quality variables.

RESULTS

Baseline CPR quality was adequate for most measures except compression depth and re-expansion. After water rescue, the single lifeguard trial showed no significant differences compared with baseline. CPR score and ventilation score of the single-lifeguard trial was higher than that of the lifeguard-bystander trial (p=0.027, p<0.001). Both the two-lifeguard trial (p=0.025), and lifeguard-bystander trial (p=0.010) had a lower percentage of breaths with correct ventilation volume and higher percentage of breaths with excessive ventilation volume (p=0.007, p=0.011, respectively) than the single-lifeguard trial. No-flow time of the lifeguard-bystander trial was longer than other trials (p<0.001).

CONCLUSIONS

Although CPR given by the lifeguard was not optimal, fatigue generated by a water rescue has no impact on the quality of subsequent CPR performed by a trained lifeguard for 10 min. Untrained bystanders assisting in CPR in a drowning event is unlikely to be helpful.

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

AIM

To analyse the effect of oxygen fraction reduction (O2 14%, equivalent to 3250 m) on Q-CPR and rescuers' physiological demands.

METHODOLOGY

A quasi-experimental study was carried out in a sample of 9 Q-CPR proficient health care professionals. Participants, in teams of 2 people, performed 10 min CPR on a Laerdal ResusciAnne mannequin (30:2 compression/ventilation ratio and alternating roles between rescuers every 2 min) in two simulated settings: T21-CPR at sea level (FiO2 of 21%) and T14 - CPR at 3250 m altitude (FiO2 of 14%). Effort self-perception was rated from 0 (no effort) to 10 (maximum demand) points.

RESULTS

Quality of chest compressions was good and similar in both conditions (T21 vs T14). However, the percentage of ventilations with adequate tidal volume was lower in altitude than at sea level conditions (35.9 ± 25.2% vs. 54.7 ± 23.2%, p = 0.035). The subjective perception of effort was significantly higher at simulated altitude (5 ± 2) than at sea level (3 ± 2) (p = 0.038). Maximum heart rate during the tests was similar in both conditions; however, mean oxygen saturation was significantly lower in altitude conditions (90.5 ± 2.5% vs. 99.3 ± 0.5%, p < 0.001).

CONCLUSION

Although performing CPR under simulated hypoxic altitude conditions significantly increases the physiological demands and subjective feeling of tiredness compared to sea level CPR, trained rescuers are able to deliver good Q-CPR in such conditions, at least in the first 10 min of resuscitation.

Coastal Fishermen as Lifesavers While Sailing at High Speed: A Crossover Study

Purpose

Starting basic cardiopulmonary resuscitation (CPR) early improves survival. Fishermen are the first bystanders while at work. Our objective was to test in a simulated scenario the CPR quality performed by fishermen while at port and while navigating at different speeds.

Methods

Twenty coastal fishermen were asked to perform 2 minutes of CPR (chest compressions and mouth-to-mouth ventilations) on a manikin, in three different scenarios: (A) at port on land, (B) on the boat floor sailing at 10 knots, and (C) sailing at 20 knots. Data was recorded using quality CPR software, adjusted to current CPR international guidelines.

Results

The quality of CPR (QCPR) was significantly higher at port (43% ± 10) than sailing at 10 knots (30% ± 15; p = 0.01) or at 20 knots (26% ± 12; p = 0.001). The percentage of ventilation that achieved some lung insufflation was also significantly higher when CPR was done at port (77% ± 14) than while sailing at 10 knots (59% ± 18) or 20 knots (57% ± 21) (p = 0.01).

Conclusion

In the event of drowning or cardiac arrest on a small boat, fishermen should immediately start basic CPR and navigate at a relatively high speed to the nearest port if the sea conditions are safe.

Prehospital Emergency Medicine at the Beach: What Is the Effect of Fins and Rescue Tubes in Lifesaving and Cardiopulmonary Resuscitation After Rescue?

OBJECTIVE

To analyze the influence of fins and rescue tube use in a water rescue, assessed by time and distance to salvage position, physiological parameters, and cardiopulmonary resuscitation (CPR).

METHODS

Twenty professional lifeguards (10 men, 10 women) conducted 3 tests: a baseline test of 5 minutes of CPR and 2 water rescues, 1 without rescue equipment (NRE), and the other with fins and rescue tube (FRT). They also had to perform 5 minutes of CPR after each rescue. Time and distance of the rescues, physiological parameters (blood lactate concentration and heart rate), and quality of CPR were analyzed.

RESULTS

CPR quality worsened by 26 to 28% (P < .001) after rescue. However, there were no differences using FRT. The use of rescue equipment reduced the time (FRT: 216±57 seconds; NRE: 319±127 seconds; P < .001) and distance covered (FRT: 265±52 m; NRE: 326±41 m; P < .001). No differences were found in lactate levels between FRT and NRE just after the rescues, but there were some after 5 minutes of subsequent CPR (FRT: 10.7±2.2 mmol/L; NRE: 12.6±1.8 mmol/L; P < .001). Comparing women with men, we found significant differences in lactate concentrations only in FRT (women: 9.6±1.4 mmol/L; men: 8.1±1.2 mmol/L; P = .031).

CONCLUSIONS

The use of fins and rescue tube provides a comprehensive benefit in an aquatic emergency. However, FRT did not have any effect on the quality of the postrescue CPR.

How can lifeguards recover better? A cross-over study comparing resting, running, and foam rolling

PURPOSE

The aim of this study is to compare the effectiveness of active recovery in form of running or foam rolling on clearing blood lactate compared to remain sitting after a water rescue.

METHOD

A quasi experimental cross-over design was used to test the effectiveness of two active recovery methods: foam rolling (FR) and running (RR), compared with passive recovery (PR) on the blood lactate clearance after performing a water rescue. Twelve lifeguards from Marín (Pontevedra) completed the study. The participants performed a 100-meter water rescue and a 25-minute recovery protocol.

RESULTS

The post recovery lactate levels were significantly lower for foam rolling (4.4±1.5mmol/l, P=0.005, d=0.94) and running (4.9±2.3mmol/l, P=0.027, d=1.21) compared with resting (7.2±2.5mmol/l); there was no significant difference between foam rolling and running (P=1.000).

CONCLUSIONS

We found that surf lifesavers clear out blood lactate more efficient when performing an active recovery protocol. Foam rolling is an effective method of increasing the rate of blood lactate clearance. These two recovery methods are also adequate for surf lifeguards as they do not interfere with the surveillance aspect of their job.

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.

Cardiopulmonary Resuscitation Quality by Helicopter Rescue Swimmers While Flying

OBJECTIVE

Our objective was to assess the cardiopulmonary resuscitation (CPR) quality by helicopter rescue swimmers (HRSs) while flying.

METHODS

Twenty HRSs from the Spanish Maritime Safety took part in this study. The research protocol included 2 phases: a baseline test (5 minutes of CPR on land) and a challenge test (5 minutes of CPR on a Sikorsky S-61N helicopter in-flight). A Laerdal Resusci Anne mannequin with Laerdal PC Skill Reporting (Stavanger, Norway) was used to register CPR variables.

RESULTS

CPR quality on land versus in-flight was not significantly different. The mean chest compression (CC) depth (52.6 mm on land vs. 51.9 mm in-flight) was inside the recommended range, but mean CC rate (133 vs. 132 per minute), tidal volume (752 vs. 888 mL), and hands-off time (9 per cycle in both tests) were above the 2015 recommended goal. Incomplete chest re-expansion was observed in 19% of on land and 26% in-flight CCs. CPR quality was maintained throughout the 5-minute challenges.

CONCLUSION

HRSs are able to perform CPR in a flying helicopter with similar quality to CPR on land. They need additional training to avoid excessive CC rates, tidal volumes, and hands-off times and to permit chest re-expansion.

Assessing the efficacy of rescue equipment in lifeguard resuscitation efforts for drowning

PURPOSE

The whole drowning process usually occurs within seconds to a few minutes. An early rescue may stop and/or prevent most medical complications. Fins, rescue tube, and rescue board (RB) are the equipment most frequently used by lifeguards. Our objective was to compare, in a water rescue quasiexperimental trial, these different pieces of rescue equipment to define the safest and with the lower rescue time as well as to assess their effects on the lifeguards' physiological state and cardiopulmonary resuscitation (CPR) performance.

METHOD

A controlled trial was conducted to study the time effect of 4 different rescue techniques and assess CPR quality, along with the physiological effects of each rescue technique (blood lactate and subjective Borg's scale effort perception) on 35 lifeguards.

RESULTS

Among the final sample subjects (n = 23), a total of 92 rescues were completed. Total water rescue time was longer without equipment (NE). The total rescue time was significantly lower using RB (P < .001). Similar good quality of CPR before and after water rescue was observed in all trials (P > .05), although correct ventilations represented less than 50% of total in all trials. Blood lactate increased after all rescues. The subjective effort Borg's scale showed significantly less effort using RB vs without equipment, fins, and fins and rescue tube.

CONCLUSION

The use of propelling and/or floating equipment saves precious time with repercussions in the reduction of drowning mortality and morbidity. The RB offers a significant advantage. Lifeguards need more CPR training, especially considering the importance of efficient ventilations for drowning victims.

Quality of continuous chest compressions performed for one or two minutes

OBJECTIVES

This study was designed to assess cardiopulmonary resuscitation quality and rescuer fatigue when rescuers perform one or two minutes of continuous chest compressions.

METHODS

This prospective crossover study included 148 lay rescuers who were continuously trained in a cardiopulmonary resuscitation course. The subjects underwent a 120-min training program comprising continuous chest compressions. After the course, half of the volunteers performed one minute of continuous chest compressions, and the others performed two minutes, both on a manikin model. After 30 minutes, the volunteers who had previously performed one minute now performed two minutes on the same manikin and vice versa.

RESULTS

A comparison of continuous chest compressions performed for one and two minutes, respectively, showed that there were significant differences in the average rate of compressions per minute (121 vs. 124), the percentage of compressions of appropriate depth (76% vs. 54%), the average depth (53 vs. 47 mm), and the number of compressions with no errors (62 vs. 47%). No parameters were significantly different when comparing participants who performed regular physical activity with those who did not and participants who had a normal body mass index with overweight/obese participants.

CONCLUSION

The quality of continuous chest compressions by lay rescuers is superior when it is performed for one minute rather than for two minutes, independent of the body mass index or regular physical activity, even if they are continuously trained in cardiopulmonary resuscitation. It is beneficial to rotate rescuers every minute when performing continuous chest compressions to provide higher quality and to achieve greater success in assisting a victim of cardiac arrest.

Mechanical chest compression with a medical parallel manipulator for cardiopulmonary resuscitation

BACKGROUND

Chest compression is the primary technique in emergency situations for resuscitating patients who have a cardiac arrest. Even for experienced personnel, it is difficult to perform chest compressions at the correct compression rate and depth.

METHODS

We describe a new translational three-revolute-revolute-revolute (3-RRR) parallel manipulator designed for delivering chest compressions. The kinematic and chest analyses have been carried out analytically. The motion of the parallel manipulator while performing chest compressions was simulated under experimental conditions and the results were verified in MSC ADAMS software.

RESULTS

Simulation and experimental results had more or less similar results. The proposed parallel manipulator was able to achieve 120 compressions/min (cpm) with a depth in the range 38-51 mm during cardio-pulmonary resuscitation (CPR).

CONCLUSIONS

The design of the manipulator makes it easy to deploy for performing chest compressions at the correct compression rate and depth, as outlined in the 2010 resuscitation guidelines.