Smaller self-inflating bags produce greater guideline consistent ventilation in simulated cardiopulmonary resuscitation

Performances and limits of Bag-Valve-Device for pre-oxygenation and manual ventilation: A comparative bench and cadaver study

INTRODUCTION

Bag-Valve-Device (BVD) is the most frequently used device for pre-oxygenation and ventilation during cardiopulmonary resuscitation (CPR). A minimal expired fraction of oxygen (FeO2) above 0.85 is recommended during pre-oxygenation while insufflated volume (VTi) should be reduced during manual ventilation. The objective was to compare the performances of different BVD in simulated conditions.

METHODS

Nine BVD were evaluated during pre-oxygenation: spontaneous breathing patients were simulated on a test lung (mild and severe conditions). FeO2 was measured with and without positive end-expiratory pressure (PEEP). CO2 rebreathing was evaluated. Then, manual ventilation was performed by 36 caregivers (n = 36) from three hospitals on a specific manikin; same procedure was repeated by 3 caregivers (n = 3) on two human cadavers with three of the nine BVD: In non-CPR scenario and during mechanical CPR with Interrupted Chest Compressions strategy (30:2).

RESULTS

Pre-oxygenation: FeO2 was lower than 0.85 for three BVD in severe condition and for two BVD in mild condition. FeO2 was higher than 0.85 in eight of nine BVD with an additional PEEP valve (PEEP 5 cmH2O). One BVD induced CO2 rebreathing. Manual ventilation: For non-CPR manual ventilation, mean VTi was within the predefined lung protective range (4-8 mL/kg PBW) for all BVD on the bench. For CPR manual ventilation, mean VTi was above the range for three BVD on the bench. Similar results were observed on cadavers.

CONCLUSIONS

Several BVD did not reach the FeO2 required during pre-oxygenation. Manual ventilation was significantly less protective in three BVD. These observations are related to the different BVD working principles.

Prehospital Manual Ventilation: An NAEMSP Position Statement and Resource Document

Manual ventilation using a self-inflating bag device paired with a facemask (bag-valve-mask, or BVM ventilation) or invasive airway (bag-valve-device, or BVD ventilation) is a fundamental airway management skill for all Emergency Medical Services (EMS) clinicians. Delivery of manual ventilations is challenging. Several strategies and adjunct technologies can increase the effectiveness of manual ventilation. NAEMSP recommends:All EMS clinicians must be proficient in bag-valve-mask ventilation.BVM ventilation should be performed using a two-person technique whenever feasible.EMS clinicians should use available techniques and adjuncts to achieve optimal mask seal, improve airway patency, optimize delivery of the correct rate, tidal volume, and pressure during manual ventilation, and allow continual assessment of manual ventilation effectiveness.

Tidal volume according to the 4-point sealing forces of a bag-valve-mask: an adult respiratory arrest simulator-based prospective, descriptive study

Background

For adequate ventilation during bag-valve-mask ventilation, rescuers should ensure a proper mask seal using the one-handed or two-handed technique. Little is known about the magnitude of sealing forces of a bag-valve-mask needed for adequate ventilation. This study aimed to explore the effect of the 4-point sealing forces of a bag-valve-mask on tidal volume while using the one-handed technique, focusing on the moderating effect of C length (the distance from the thumb to the index finger in the C shape of the one-hand EC grip).

Methods

A prospective, descriptive simulation study was conducted. A convenience sample of 125 undergraduate paramedic students from two universities was recruited. A self-reported questionnaire was used to collect subjective variables. Tidal volumes, 4-point sealing forces of the mask, peak pressure, and C length of the C shape in the one-hand EC grip were measured using the mechanical lung model under a simulated adult respiratory arrest. Hierarchical regression analysis was used to determine the moderating effect of C length on tidal volume in bag-valve-mask ventilation.

Results

The average C length, peak pressure, and tidal volume were 7.54 (± 1.85) cm, 11.62 (± 5.40) cmH₂O, and 321.66 (± 135.18) mL, respectively. The average range of the 4-point sealing forces was 0.03–0.69 N. The apex sealing force was the weakest among the 4-point sealing forces. Hierarchical regression analysis demonstrated that tidal volume accounted for 62.7% of the variance by C length, peak pressure, and apex sealing force during bag-valve-mask ventilation (F = 9.676, p < 0.001). C length moderated the effect of the apex sealing force and peak pressure on the tidal volume, meaning the higher the peak pressure and apex sealing force, the more the tidal volume and the longer the C length.

Conclusion

This first simulation study measuring the 4-point sealing forces during bag-valve-mask ventilation provides effective advice that can be adopted in clinical practice without side effects and underpins the importance of continuous retraining and assessment focused on individual physical characteristics, such as C length and bag-valve-mask sealing forces.

Optimizing airway management and ventilation during prehospital advanced life support in out-of-hospital cardiac arrest: A narrative review

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.

Ventilation feedback device for manual ventilation in simulated respiratory arrest: a crossover manikin study

Background

Studies have shown that providing adequate ventilation during CPR is essential. While hypoventilation is often feared by most caregivers on the scene, the most critical problem remains hyperventilation. We developed a Ventilation Feedback Device (VFD) for manual ventilation which monitors ventilatory parameters and provides direct feedback about ventilation quality to the rescuer. This study aims to compare the quality of conventional manual ventilation to ventilation with VFD on a simulated respiratory arrest patient.

Methods

Forty healthcare providers were enrolled and instructed to ventilate a manikin simulating respiratory arrest. Participants were instructed to ventilate the manikin for 5 min with and without the VFD in random order. They were divided in two groups of 20 people, one group ventilating through a mask and the other through an endotracheal tube.

Results

Ventilation with the VFD improved from 15 to 90% (p < 0.001) with the mask and from 15 to 85% (p < 0.001) with the endotracheal tube (ETT) by significantly reducing the proportion of hyperventilation. The mean ventilation rates and tidal volumes were in the recommended ranges in respectively 100% with the mask and 97.5% of participants with the ETT when using the VFD.

Conclusion

VFD improves the performance of manual ventilation by over 70% in different simulated scenarios. By providing the rescuer direct feedback and analysis of ventilatory parameters, this device can significantly improve ventilation while performing CPR and thus save lives.

Real-time tidal volume feedback guides optimal ventilation during simulated CPR

PURPOSE

We performed this study to investigate whether real-time tidal volume feedback increases optimal ventilation and decreases hyperventilation during manikin-simulated cardiopulmonary resuscitation (CPR).

BASIC PROCEDURES

We developed a new real-time tidal volume monitoring device (TVD) which estimated tidal volume in real time using a magnetic flowmeter. The TVD was validated with a volume-controlled mechanical ventilator with various tidal volumes. We conducted a randomized, crossover, manikin-simulation study in which 14 participants were randomly divided into a control (without tidal volume feedback, n = 7) and a TVD group (with real-time tidal volume feedback, n = 7) and underwent manikin simulation. The optimal ventilation was defined as 420-490 mL of tidal volumes for a 70-kg adult manikin. After 2 weeks of the washout period, the simulation was repeated via the participants' crossover.

MAIN FINDINGS

In the validation study, 97.6% and 100% of the difference ratios in tidal volumes between the mechanical ventilator and TVD were within ±1.5% and ±2.5%, respectively. During manikin-simulated CPR, TVD use increased the proportion of optimal ventilation per person. Its median values (range) of the control group and the TVD group were 37.5% (0.0-65.0) and 87.5% (65.0-100.0), respectively, P < .001). TVD use also decreased hyperventilation. The proportions of hyperventilation in the control group and the TVD group were 25.0% vs 8.9%, respectively (P < .001).

PRINCIPAL CONCLUSIONS

Real-time tidal volume feedback using the new TVD guided the rescuers to provide optimal ventilation and to avoid hyperventilation during manikin-simulated CPR.

Performance of manual ventilation: how to define its efficiency in bench studies? A review of the literature

Bench studies have become the preferred way to evaluate the performance of airway equipment, since clinical trials are not specifically required before marketing these devices. However, it is difficult to assess the efficiency of ventilation without recording physiological data. This review analyses how efficiency of manual ventilation has been defined in recent studies, and how their results may be affected. We searched electronic databases from 2000 to April 2014. The main inclusion criterion was the analysis of performance of ventilation. Nine relevant articles were selected from 53 eligible publications. Most studies used the same parameters; tidal volume and ventilation rate. However, there were significant differences between the definitions of performance of ventilation, both in terms of criteria of judgement and methods of analysis. None of these approaches is able to provide a clear understanding of variability of ventilation during a given period. A new definition may increase the relevance of bench studies to clinical medicine, by more appropriately assessing the performance of ventilation.

Mapping the use of simulation in prehospital care - a literature review

Background

High energy trauma is rare and, as a result, training of prehospital care providers often takes place during the real situation, with the patient as the object for the learning process. Such training could instead be carried out in the context of simulation, out of danger for both patients and personnel. The aim of this study was to provide an overview of the development and foci of research on simulation in prehospital care practice.

Methods

An integrative literature review were used. Articles based on quantitative as well as qualitative research methods were included, resulting in a comprehensive overview of existing published research. For published articles to be included in the review, the focus of the article had to be prehospital care providers, in prehospital settings. Furthermore, included articles must target interventions that were carried out in a simulation context.

Results

The volume of published research is distributed between 1984- 2012 and across the regions North America, Europe, Oceania, Asia and Middle East. The simulation methods used were manikins, films, images or paper, live actors, animals and virtual reality. The staff categories focused upon were paramedics, emergency medical technicians (EMTs), medical doctors (MDs), nurse and fire fighters. The main topics of published research on simulation with prehospital care providers included: Intubation, Trauma care, Cardiac Pulmonary Resuscitation (CPR), Ventilation and Triage.

Conclusion

Simulation were described as a positive training and education method for prehospital medical staff. It provides opportunities to train assessment, treatment and implementation of procedures and devices under realistic conditions. It is crucial that the staff are familiar with and trained on the identified topics, i.e., intubation, trauma care, CPR, ventilation and triage, which all, to a very large degree, constitute prehospital care. Simulation plays an integral role in this. The current state of prehospital care, which this review reveals, includes inadequate skills of prehospital staff regarding ventilation and CPR, on both children and adults, the lack of skills in paediatric resuscitation and the lack of knowledge in assessing and managing burns victims. These circumstances suggest critical areas for further training and research, at both local and global levels.

Cardiopulmonary resuscitation quality: [corrected] improving cardiac resuscitation outcomes both inside and outside the hospital: a consensus statement from the American Heart Association

The "2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care" increased the focus on methods to ensure that high-quality cardiopulmonary resuscitation (CPR) is performed in all resuscitation attempts. There are 5 critical components of high-quality CPR: minimize interruptions in chest compressions, provide compressions of adequate rate and depth, avoid leaning between compressions, and avoid excessive ventilation. Although it is clear that high-quality CPR is the primary component in influencing survival from cardiac arrest, there is considerable variation in monitoring, implementation, and quality improvement. As such, CPR quality varies widely between systems and locations. Victims often do not receive high-quality CPR because of provider ambiguity in prioritization of resuscitative efforts during an arrest. This ambiguity also impedes the development of optimal systems of care to increase survival from cardiac arrest. This consensus statement addresses the following key areas of CPR quality for the trained rescuer: metrics of CPR performance; monitoring, feedback, and integration of the patient's response to CPR; team-level logistics to ensure performance of high-quality CPR; and continuous quality improvement on provider, team, and systems levels. Clear definitions of metrics and methods to consistently deliver and improve the quality of CPR will narrow the gap between resuscitation science and the victims, both in and out of the hospital, and lay the foundation for further improvements in the future.