Elsevier

Resuscitation

Volume 61, Issue 1, April 2004, Pages 55-61
Resuscitation

Performing chest compressions in a confined space

https://doi.org/10.1016/j.resuscitation.2003.11.012Get rights and content

Abstract

Standard cardiopulmonary resuscitation (CPR) may be difficult to perform in a confined space. This study set out to evaluate alternative techniques of chest compression, which may be easier to perform in such situations. Nineteen airline employees, trained in basic life support (BLS), were recruited to take part in the study. Following refresher training in standard one- and two-person CPR, they were taught two alternative techniques of chest compression: one-person over-the-head (OTH) and two-person straddle (STR). Their performances of chest compression during one-person standard CPR (St-1) and two-person standard CPR (St-2) were then compared with their performances during OTH and STR using a recording manikin. There were no statistically significant differences between the two-person methods of compression (St-2 and STR) for any of the parameters measured. There were no statistically significant differences between the one-person methods of chest compression (St-1 and OTH) for the average compression rate, the number of chest compressions achieved in a minute, or the average hands-off time per cycle. For OTH the average compression depth was significantly less than for St-1 (P=0.0149) and there were more compressions of incorrect depth (P=0.0400). The average duty cycle was significantly higher for OTH (P=0.0045). 30.4% of compressions were incorrectly placed for OTH compared with 7.7% for St-1 (P=0.0025). It was concluded that the quality of chest compression during two-person straddle CPR compares favorably with chest compression during standard two-person CPR, and may be useful in situations where space is limited. If only one rescuer is available to perform CPR, and limited space makes it impossible to carry out standard CPR, over-the-head CPR is an alternative method. However, in this study, hand placement during chest compression was poor, and additional training may be necessary before it can be considered a safe technique.

Sumàrio

A Reanimação Cardio-Pulmonar (CPR) standard pode ser difı́cil de realizar num espaço confinado. Este estudo foi desenhado para avaliar técnicas alternativas de compressão torácica, que podem ser mais fáceis de executar nessas circunstâncias. Foram recrutados para participar no estudo dezanove empregados das linhas aéreas, treinados em Suporte Básico de Vida (SBV). Depois de uma revisão de treino em reanimação cardio-pulmonar standard com um ou dois reanimadores, foram ensinadas duas técnicas alternativas de compressão torácica: uma pessoa do lado da cabeça (OTH) e duas pessoas “posicionada em cela sobre a vı́tima” (STR). O seu desempenho das compressões torácicas durante a reanimação standard com uma pessoa (St-1) e duas pessoas (St-2) foi então comparado com o seu desempenho durante OTH e STR utilizando um manequim de registo. Não existiram diferenças estatisticamente significativas entre os métodos de compressões torácicas com duas pessoas (St-2 e STR) para nenhum dos parâmetros medidos. Não existiram diferenças estatisticamente significativas entre os métodos de compressões torácicas com uma pessoa (St-1 e OTH) para a taxa de compressão média, o número de compressões torácicas obtidas num minuto, ou o número médio de tempo por ciclo “sem mãos a reanimar”. Para a OTH a média e profundidade das compressões foi significativamente menor do que para a St-1 (P=0.0149) e houve mais compressões de profundidade incorrecta (P=0.0400). O tempo médio do ciclo obrigatório foi significativamente maior para OTH (P=0.045). Nas OTH 30.4% das compressões foram incorrectamente posicionadas comparativamente com 7.7% para St-1 (P=0.0025). Concluı́mos que a qualidade das compressões torácicas durante a reanimação STR com duas pessoas é favorável em comparação com o método standard, e pode ser útil nas situações em que o espaço é limitado. Quando só está disponı́vel um reanimador para realizar CPR, e a disponibilidade de espaço não permite a realização de CPR standard, CPR com uma pessoa do lado da cabeça é um método alternativo. Contudo, neste estudo, a posição das mãos durante a compressão torácica foi má, e pode ser necessário treino adicional antes desta poder ser considerada uma técnica segura.

Resumen

La reanimación cardiopulmonar estándar (CPR) puede ser difı́cil de realizar en un espacio confinado. Este estudio busca evaluar técnicas alternativas de compresión torácica, las que pueden ser mas fáciles de realizar en tales situaciones. Se reclutaron 19 empleados de lı́nea aérea, entrenados en soporte vital básico (BLS), para tomar parte en este estudio. Después de un entrenamiento para refrescar conocimientos en CPR estándar con uno y dos operadores, se les enseñó dos técnicas alternativas de compresiones torácicas: un operador sobre la cabeza (OTH) y dos operadores a horcajadas(STR).Se compararon sus desempeños en compresiones torácicas durante CPR estándar de un operador (St-1) y CPR estándar con dos operadores(St-2) con los desempeños en OTH y STR, usando un maniquı́ con sistema de registro. No hubo diferencias estadı́sticamente significativas entre los métodos de compresión para dos operadores (St-2 ySTR) para ninguno de los parámetros medidos. No hubo diferencias estadı́sticamente significativas entre los métodos de compresión para un operador (St-1 y OTH) en frecuencia de compresión promedio, numero de compresiones realizadas en un minuto o en el tiempo promedio sin compresiones por ciclo. En OTH la profundidad promedio de las compresiones fue significativamente menor que para St-1 (P=0.0149) y hubo mas compresiones de profundidad incorrecta (P=0.0400). La facción de ciclo promedio fue significativamente más alta para OTH (P=0.0045). Con OTH el 30.4% de las compresiones estuvieron incorrectamente ubicadas comparadas con el 7.7% con St-1 (P=0.0025). Se concluyó que la calidad de las compresiones torácicas durante el CPR con dos personas a horcajadas se compara favorablemente con compresiones torácicas CPR estándar de dos operadores, y puede ser útil en situaciones donde el espacio está limitado. Si hay solo un reanimador disponible para realizar CPR, y el espacio limitado hace imposible realizar CPR estándar, el método alternativo es el método sobre la cabeza. Sin embargo, en este estudio, la ubicación de las manos durante las compresiones fue pobre, y puede ser necesario entrenamiento adicional antes de poder considerarlo una técnica segura.

Introduction

The guidelines for basic life support (BLS) published by the Resuscitation Council (UK) [1], the European Resuscitation Council (ERC) [2], and the International Liaison Committee on Resuscitation (ILCOR) [3], all describe the technique for manual chest compression. Although none of the publications state that the rescuer giving chest compressions should kneel by the side of the victim, this is implied in the text and shown in the accompanying illustrations.

There are situations when cardiac arrest may occur in a confined space, making it difficult to kneel by the side of the victim; examples are in an aircraft or in an ambulance. Anecdotally, rescuers have performed chest compression whilst kneeling at the head of the victim or straddling the upper part of the legs, leaning forwards to give the compressions.

Two studies of one-person over-the-head (OTH) cardiopulmonary resuscitation (CPR) have been reported. In the first, it was concluded that the quality of CPR using this technique was as good as that during two-person standard CPR, except that fewer chest compressions were delivered each minute [4]. In the second study, over-the-head chest compression was combined with bag-valve-mask ventilation; this resulted in CPR that conformed closely to ERC guidelines [5].

Airline cabin crew in the UK are taught basic life support in accordance with the guidelines of the ERC, but use a two-person mouth-to-mask technique with added oxygen for ventilation [6], [7]. In the confines of an aircraft aisle, it may be difficult to perform standard CPR with one or two rescuers kneeling at the side of the victim. An alternative for a single rescuer is to ventilate and compress whilst at the head of the victim. For two rescuers, it is possible for one rescuer to ventilate from the head and the other to perform chest compression whilst straddling the victim’s legs.

The purpose of this study was to compare, on a manikin, the efficacy of chest compression during four methods of CPR, two of which would potentially be easier to perform in a confined space, specifically the aisles of an aircraft.

Section snippets

Ethics

For a previous similar study (comparing the outcome of training) the local (Colchester) Ethics Committee Chairman declared that such a study did not require ethical approval. No database was kept that would allow identification of the individuals concerned. All those acting as volunteers were from the training department of one of the airlines interested in the practical aspects of resuscitation on board an aircraft.

Material and methods

A total of 19 volunteers were recruited from the crew training staff of Virgin Atlantic Airways Ltd. Six of these taught CPR as part of their duties but all nineteen had received training and regular re-training in standard one- and two-person CPR.

The nature of the study was explained to each volunteer, and his or her verbal consent to participate was obtained.

Although names were recorded for identification purposes, these were deleted from the subsequent analysis sheets to maintain

Data recording

The Laerdal AED Resusci© Anne manikin has sensing devices and computer software that allowed continuous recording of the following data:

  • (a)

    total number of compressions given;

  • (b)

    average rate of chest compression per minute;

  • (c)

    average number of compressions given per minute;

  • (d)

    depth of each chest compression: correct; too shallow; too deep (parameters for correct”=38±2 mm to 51±2 mm);

  • (e)

    position of hands on manikin chest (each compression): correct; high; low; left; right (“correct” = over lower half of sternum;

Statistical methods

The data were analyzed using two-way analysis of variance (ANOVA), the two factors being the individual and the CPR technique. Pair-wise analysis, using each individual as their own control and transformation of the percentage data to stabilize variance estimates, did not produce any different conclusions and are not presented.

Results

A total of 19 volunteers took part, 9 male and 10 female, ranging in age from 26 to 52 years. Each was tested performing four cycles of CPR (60 compressions) using each of the four methods (St-1; OTH; St-2; STR). Three volunteers inadvertently gave a total of 61 compressions, one gave 62 compressions and one gave 58 compressions, each on one occasion only. These small errors were ignored as being insignificant as far as overall performance was concerned, particularly as errors in compression

Discussion

The manikin was able to record variables in performance of ventilation (number of ventilations; rate of delivery; volume of air), but these are not included in the results for two reasons. First, the main objective of the study was to compare the differences in chest compression technique during the four methods of CPR. Second, none of the volunteers had been taught the use of a Pocket Mask as a single rescuer.

Certain aspects of performance were common to all four methods. Thus, around 50% of

Conclusions

The quality of chest compression during the straddle method, performed as part of two-person CPR, appears to be as good as that during standard two-person CPR. It may be a more useful method in situations where space is limited, for example in an aircraft aisle.

In this study, chest compressions were performed as well during over-the-head as during standard one-person CPR with the exception of hand position on the chest. Sufficient of the compressions were placed dangerously low to conclude that

Acknowledgements

The authors are very grateful for the statistical help given by David Irvine, Epidemiologist, of British Airways Plc, and to the members of the AirCrew Training Department of Virgin Atlantic Airways Ltd who acted as volunteers. Laerdal Medical Ltd kindly loaned the manikin and laptop used in the study and provided the necessary software. The project was supported by a research grant from the Resuscitation Council (UK).

Conflict of interests: Dr. Anthony Handley is Chairman of the BLS/AED

References (15)

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