Time used for ventilation in two-rescuer CPR with a bag-valve-mask device during out-of-hospital cardiac arrest

doi:10.1016/j.resuscitation.2007.11.005

Resuscitation

Volume 77, Issue 1, April 2008, Pages 57-62

https://doi.org/10.1016/j.resuscitation.2007.11.005 Get rights and content

Summary

Introduction

Professional rescuers only deliver chest compressions 39% of the available time before intubation during out-of-hospital cardiac arrest. In manikin-studies lay rescuers need approximately 15 s to deliver two ventilations. It is not known how much time professional rescuers use for two ventilations and we hypothesised that the time used for two ventilations with a bag-valve-mask device before tracheal intubation is longer than recommended and that the extended time contributes to the high no flow time.

Methods

Quality of CPR was available for analysis in 628 cases of out-of-hospital cardiac arrest in the ambulance service in Oslo, Akershus, London, and Stockholm from 2002 to 2005. The 2000 Guidelines were used as the reference. Ventilations were registered from changes in transthoracic impedance as measured through the standard defibrillation pads. We included episodes only with CPR with a 15:2 pattern for at least 1 min and identified all pauses between chest compressions before intubation.

Results

In the remaining 172 episodes we identified 3097 chest compression pauses. In 1587 (51%) of the pauses we identified two ventilations and a mean pause length for each episode was calculated. The median of these means was 5.5 s (IQR; 4.5, 7). These pauses comprised a median 9% (IQR; 4%, 15%) of the time before intubation in these episodes. In 892 (29%) of the pauses we identified a different number of ventilations, or other interventions in addition to ventilation. In the remaining 618 pauses (20%) no ventilations were registered.

Conclusions

Professional rescuers delivered two bag-valve-mask ventilations within the 5–6 s as indicated in the 2000 Guidelines, slightly longer than the 3–4 s recommended in the 2005 Guidelines. However, only half the pauses were used for two ventilations, and the total time for two ventilations accounted for only 27% of the time without chest compressions. Excessive time for ventilation cannot explain the high no-flow time during CPR by professional rescuers before intubation.

Introduction

The quality of CPR performed by professional rescuers during out-of-hospital cardiac arrest has been found to be substandard in several studies.1, 2, 3 In particular, the fraction of time without chest compressions (no flow time) has been too high. First responders performed chest compressions only 43% of the time during the resuscitation effort in unintubated patients in the study by Valenzuela et al.² and in our earlier study the ambulance personnel compressed the chest only 39% of the time before intubation.⁴

While lay rescuers have been shown to need approximately 15 s to deliver two ventilations in a number of manikin studies,5, 6, 7 a study from our group showed that ambulance personnel used 5 ± 1 s to deliver two ventilations with a bag-valve-mask device on manikins in a two-rescuer situation.⁸ This is within the interval indicated in the 2000 Guidelines which recommend 2 s per inflation⁹ while the 2005 Guidelines recommend a shorter interval of only 3–4 s with only 1 s per inflation.¹⁰ Although this shows that professional rescuers are capable of giving two ventilations close to guideline recommendations,9, 10 there may be differences between ventilating manikins in the laboratory or training station and ventilating real patients in the field.

It is not known how much time professional rescuers use to deliver two bag-valve-mask ventilations in a two-rescuer situation out-of-hospital, and we hypothesise that it is longer than recommended, and thus a central contributor to the high no flow time. We have analysed our previously published data from the ambulance services in London, Stockholm and Akershus1, 3 in more detail and added similar data from the ambulance service in Oslo, Norway, to calculate the contribution of bag-valve-mask ventilations to the time without chest compressions.

Section snippets

Materials and methods

The methods have been described in detail previously1, 3, 11 and a more condensed version is presented here.

Results

The quality of CPR was available for analysis in 628 cases of out-of-hospital cardiac arrest. Only 172 episodes had at least 1 min of CPR with 15 compressions and two ventilations before intubation and could be included in the analysis. In the 456 episodes that were excluded the signal quality was too poor in 83, while 373 episodes included less than the required minimum of 1 min of 15:2 CPR before intubation; in 52 episodes the patient was intubated within the first minute, in 60 before the

Discussion

In the present study bag-valve-mask ventilations were delivered within the 2000 Guideline timeframe of 5–6 s,⁹ slightly longer than the 3–4 s recommended in 2005¹⁰ and the compression pauses for series of two ventilations as recommended by the guidelines accounted for only 9% of the time before intubation. This increased to 15% when adding 5.5 s (the median compression pause observed for two ventilations) for each of the other ventilation pauses with a different number of ventilations or other

Conclusion

Professional rescuers can deliver bag-valve-mask ventilations close to the recommended guideline time frame. Excessive time for ventilation does not explain the unwarranted pauses in chest compressions seen during CPR by professional rescuers.

Conflict of interest statement

Authors Ødegaard, Pillgram, Berg, Olasveengen and Kramer-Johansen have no conflict of interests to declare.

Acknowledgements

We would like to thank all participating ambulance personnel who contributed to this study with their enthusiasm and efforts. We also thank Petter Andreas Steen for his critical review of the article and administrative support. The experimental defibrillators were kindly provided by Laerdal Medical, Stavanger, Norway and Philips Medical Systems, Andover, MA, USA. Code-Stat Reviewer was provided by Physio Control and Sister Studio by Laerdal Medical, both free of charge.

Funding: Funding for this

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Cited by (18)

Manual chest compression pause duration for ventilations during prehospital advanced life support – An observational study to explore optimal ventilation pause duration for mechanical chest compression devices
2022, Resuscitation
Citation Excerpt :
They might need more time to provide two insufflations when compared to ambulance nurses with more experience and a more advanced airway management technique. In a previous study by Ødegaard et al. in the prehospital ALS context, the median compression pause duration was 5.5 seconds (IQR 4.5–7).10 In all pauses analysed, two insufflations were detected in only 51%.
Mechanical chest compression devices in the 30:2 mode generally provide a pause of three seconds to give two insufflations without evidence supporting this pause duration. We aimed to explore the optimal pause duration by measuring the time needed for two insufflations, during advanced life support with manual compressions.
Prospectively collected data in the AmsteRdam REsuscitation STudies (ARREST) registry were analysed, including thoracic impedance signal and waveform capnography from manual defibrillators of the Amsterdam ambulance service. Compression pauses were analysed for number of insufflations, time interval from start of the compression pause to the end of the second insufflation, chest compression pause duration and ventilation subintervals.
During 132 out-of-hospital cardiac arrests, 1619 manual chest compression pauses to ventilate were identified. In 1364 (84%) pauses, two insufflations were given. In 28% of these pauses, giving two insufflations took more than three seconds. The second insufflation is completed within 3.8 seconds in 90% and within 5 seconds in 97.5% of these pauses. An increasing likelihood of achieving two insufflations is seen with increasing compression pause duration up to five seconds.
The optimal chest compression pause duration for mechanical chest compression devices in the 30:2 mode to provide two insufflations, appears to be five seconds, warranting further studies in the context of mechanical chest compression. A 5-second pause will allow providers to give two insufflations with a very high success rate. In addition, a 5-second pause can also be used for other interventions like rhythm checks and endotracheal intubation.
Optimizing airway management and ventilation during prehospital advanced life support in out-of-hospital cardiac arrest: A narrative review
2021, Best Practice and Research: Clinical Anaesthesiology
Airway management and ventilation are essential components of cardiopulmonary resuscitation to achieve oxygen delivery in order to prevent hypoxic injury and increase the chance of survival. Weighing the relative benefits and downsides, the best approach is a staged strategy; start with a focus on high-quality chest compressions and defibrillation, then optimize mask ventilation while preparing for advanced airway management with a supraglottic airway device. Endotracheal intubation can still be indicated, but has the largest downsides of all advanced airway techniques. Whichever stage of airway management, ventilation and chest compression quality should be closely monitored. Capnography has many advantages and should be used routinely. Optimizing ventilation strategies, harmonizing ventilation with mechanical chest compression devices, and implementation in complex and stressful environments are challenges we need to face through collaborative innovation, research, and implementation.
Impact of laryngeal tube use on chest compression fraction during out-of-hospital cardiac arrest. A prospective alternate month study
2015, Resuscitation
Citation Excerpt :
As a consequence, the 2010 European Resuscitation Council Guidelines for adult CPR emphasize the absolute necessity of minimizing chest compression pauses during CPR and expert consensus is that an 80% CCF should be targeted.1,8 Cardiac rhythm analysis by automated defibrillator and bag-valve mask (BVM) ventilation with a 30:2 ratio are the main causes of chest compression interruptions.9–11 About 25% of the interruptions is directly linked to the alternation of chest compressions and ventilations.10
Supraglottic devices are thought to allow efficient ventilation and continuous chest compressions during cardiac arrest. Therefore, the use of supraglottic devices could increase the chest compression fraction (CCF), a critical determinant of patient survival. The aim of this study was to assess the CCF in out-of-hospital cardiac arrest (OHCA) patients ventilated with a supraglottic device.
We conducted an open prospective multicenter study with temporal clusters. OHCA patients treated by emergency nurses received either intermittent chest compressions with bag-valve mask ventilations (30:2 rhythm; BVM group); or continuous chest compressions with asynchronous ventilations by laryngeal tube (LT group). The primary endpoint was the CCF assessed using an accelerometer connected to the defibrillator. We also investigated the ease of use of the laryngeal tube.
Eighty-two patients were included (41 in each group); 68% were male and the median age was 68 (54–80) years. Patients and cardiac arrest characteristics did not differ between groups. The CCF was 75% (68–79%) in the LT group and 59% (51–68%) in the BVM group (p < 0.01). LT insertion failed in nine out of 40 cases (23%). The median time of LT insertion was 26 s (11–56 s). CCF was significantly lower when LT insertion failed (58% (48–74%) vs. 76% (72–80%) when LT insertion succeeded; p = 0.01).
The use of the LT during OHCA increases the CCF when compared to standard BVM ventilation. However, the impact of LT use on mortality remains unclear.
Feasibility of automated rhythm assessment in chest compression pauses during cardiopulmonary resuscitation
2013, Resuscitation
Citation Excerpt :
Pauses shorter than 3 s were normally associated with exceeding ventilation rates or were caused by an overlap between the end of the second insufflation and the beginning of the chest compression series. Our result for the median of the mean durations of the pauses with two ventilations, 5.1 s (4.2–6.4 s), is similar to the value reported in a previous study,30 which was based on data extracted from the same original episodes.4 These durations are in accordance with the values established by the guidelines for two ventilations.
To demonstrate the feasibility of doing a reliable rhythm analysis in the chest compression pauses (e.g. pauses for two ventilations) during cardiopulmonary resuscitation (CPR).
We extracted 110 shockable and 466 nonshockable segments from 235 out-of-hospital cardiac arrest episodes. Pauses in chest compressions were already annotated in the episodes. We classified pauses as ventilation or non-ventilation pause using the transthoracic impedance. A high-temporal resolution shock advice algorithm (SAA) that gives a shock/no-shock decision in 3 s was launched once for every pause longer than 3 s. The sensitivity and specificity of the SAA for the analyses during the pauses were computed.
We identified 4476 pauses, 3263 were ventilation pauses and 2183 had two ventilations. The median of the mean duration per segment of all pauses and of pauses with two ventilations were 6.1 s (4.9–7.5 s) and 5.1 s (4.2–6.4 s), respectively. A total of 91.8% of the pauses and 95.3% of the pauses with two ventilations were long enough to launch the SAA. The overall sensitivity and specificity were 95.8% (90% low one-sided CI, 94.3%) and 96.8% (CI, 96.2%), respectively. There were no significant differences between the sensitivities (P = 0.84) and the specificities (P = 0.18) for the ventilation and the non-ventilation pauses.
Chest compression pauses are frequent and of sufficient duration to launch a high-temporal resolution SAA. During these pauses rhythm analysis was reliable. Pre-shock pauses could be minimised by analysing the rhythm during ventilation pauses when CPR is delivered at 30:2 compression:ventilation ratio.
Will medical examination gloves protect rescuers from defibrillation voltages during hands-on defibrillation?
2012, Resuscitation
Citation Excerpt :
Pauses in chest compressions during CPR are known to be detrimental to survival.1 The 2005 American Heart Association Guidelines eliminated some reasons for pauses,2 but interruptions still occur to allow intubation,3 ventilations,4 AED analyses, charging, and defibrillation shocks.5 While shock delivery accounts for a relatively minor fraction of the total hands-off time in most cases, elimination of the shock pause is consistent with the overall goal of minimizing hands-off time.
Continuing compressions during a defibrillation shock has been proposed as a method of reducing pauses in cardiopulmonary resuscitation (CPR) but the safety of this procedure is unproven. The medical examination gloves worn by rescuers play an important role in protecting the rescuer yet the electrical characteristics of these gloves are unknown. This study examined the response of medical examination gloves to defibrillation voltages.
Part 1 of this study measured voltage–current curves for a small sample (8) of gloves. Part 2 tested more gloves (460) to determine the voltage required to produce a specific amount of current flow. Gloves were tested at two current levels: 0.1 mA and 10 mA. Testing included four glove materials (chloroprene, latex, nitrile, and vinyl) in a single layer and double-gloved.
All gloves tested in part 1 allowed little current to flow (<1 mA) as the voltage was increased until breakdown occurred, at which point current flow increased precipitously. In part 2, 118 of 260 (45%) single gloves and 93 of 120 (77%) double gloves allowed at least 0.1 mA of current flow at voltages within the external defibrillation voltage range. Also, 6 of 80 (7.5%) single gloves and 5 of 80 (6.2%) double gloves allowed over 10 mA.
Few of the gloves tested limited the current to levels proven to be safe. A lack of sensation during hands-on defibrillation does not guarantee that a safety margin exists. As such, we encourage rescuers to minimize rather than eliminate the pause in compressions for defibrillation.
The challenge of CPR quality: Improvement in the real world
2008, Resuscitation

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^☆: A Spanish translated version of the summary of this article appears as Appendix in the final online version at doi:10.1016/j.resuscitation.2007.11.005.

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Clinical paperTime used for ventilation in two-rescuer CPR with a bag-valve-mask device during out-of-hospital cardiac arrest☆

Summary

Introduction

Methods

Results

Conclusions

Introduction

Section snippets

Materials and methods

Results

Discussion

Conclusion

Conflict of interest statement

Acknowledgements

Resuscitation

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Resuscitation

Clinical paper
Time used for ventilation in two-rescuer CPR with a bag-valve-mask device during out-of-hospital cardiac arrest☆