Evaluation of manual and automatic manually triggered ventilation performance and ergonomics using a simulation model

Using gel for difficult mask ventilation on the bearded patients: a simulation-based study

The beard is a well-known cause of difficult mask ventilation due to excessive air leaks. Various techniques have been proposed to overcome this difficulty, such as applying a gel on the mask edge. Our objective was to determine whether the gel technique will improve ventilation and to assess the comfort of the provider. A randomized crossover design was conducted to assess the efficacy of gel in a bearded simulation model. Respiratory therapists (RT) were recruited by convenience sampling to hold the mask using a two-handed technique for a two-minute ventilation session. During the session, the ventilator provided a fixed Tidal Volume (TV) of 550 mL and a respiratory rate of 12 per minute, and the simulated model measured the received volumes. We compared the median TV and number of failed ventilation attempts with or without the gel. The comfort level while using the gel was assessed with constructed questions. We recruited 74 respiratory therapists working in Riyadh city. More than half of the participants had more than 5 years experience. The median tidal volume for standard mask ventilation without the gel was 283 mL [interquartile range (IQR) 224, 327], whereas that with the gel was 467 mL [451, 478], respectively (p < 0.01). The number of successful ventilations was recorded out of 24 breaths during the 2-min ventilation period for each technique; the proportion of successful ventilations increased significantly by 65% (95% CI 51-75%, p < 0.01) with the gel. In addition, only nine participants believed the technique was not comfortable, while the remaining individuals found it comfortable or natural. In our bearded simulation model, applying the gel significantly improved ventilation without negatively affecting comfort. Further studies and education are encouraged in the field of basic airway management.

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.

Human Factors and Simulation in Emergency Medicine

This consensus group from the 2017 Academic Emergency Medicine Consensus Conference "Catalyzing System Change through Health Care Simulation: Systems, Competency, and Outcomes" held in Orlando, Florida, on May 16, 2017, focused on the use of human factors (HF) and simulation in the field of emergency medicine (EM). The HF discipline is often underutilized within EM but has significant potential in improving the interface between technologies and individuals in the field. The discussion explored the domain of HF, its benefits in medicine, how simulation can be a catalyst for HF work in EM, and how EM can collaborate with HF professionals to effect change. Implementing HF in EM through health care simulation will require a demonstration of clinical and safety outcomes, advocacy to stakeholders and administrators, and establishment of structured collaborations between HF professionals and EM, such as in this breakout group.

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.

Reliability of manikin-based studies: an evaluation of manikin characteristics and their impact on measurements of ventilatory variables

Findings from manikin-based studies on ventilation are commonly directly extrapolated to clinical practice. The aim of this study was to determine how the use of manikins affects measurements of ventilatory variables. We connected a lung simulator to a manikin, which was then ventilated at different inspiratory flows. We defined three experimental models to compare measurements of ventilatory variables between the mechanical ventilator and the lung simulator. Even when no leakage occurred, significant tidal volume deviations were observed; from a mean (SD) of 21 (2) ml to 49 (9) ml, and from 40 (4) ml to 88 (5) ml for invasive and non-invasive ventilation, respectively (p < 0.001). Significant peak pressure deviations from 0.7 (0.1) cmH2 O to 10.6 (0.3) cmH2 O were also recorded during non-invasive ventilation (p < 0.001). Evaluation of manikin resistance and airway dead space may be essential to limit study bias. We suggest a recalibration of the recorded data if comparisons are made between different tests performed at different inspiratory flows.