To intubate or not: ventilation is the question. A manikin-based observational study

Prehospital airway management for out-of-hospital cardiac arrest: A nationwide multicenter study from the KoCARC registry

AIM

This study investigated whether prehospital advanced airway management (AAM) is associated with improved survival of out-of-hospital cardiac arrest (OHCA) compared with conventional bag-valve-mask (BVM) ventilation.

METHODS

We investigated the neurologically favorable survival of adult patients with OHCA who underwent BVM or AAM using the Korean Cardiac Arrest Research Consortium (KoCARC), a multicenter OHCA registry of Korea. The differences in clinical characteristics were adjusted by matching or weighting the clinical propensity for use of AAM or by least absolute shrinkage and selection operator (LASSO). The primary outcome was 30-day survival with neurologically favorable status defined by cerebral performance category 1 or 2.

RESULTS

Of the 9,616 patients enrolled (median age = 71 years; 65% male), there were 6,243 AAM and 3,354 BVM patients. In unadjusted analysis, the 30-day neurologically favorable survival was lower in the AAM group compared with the BVM group (5.5% vs. 10.0%; hazard ratio [HR] = 1.21, 95% confidence interval [CI] = 1.16 to 1.27; all p < 0.001). In propensity score matching-adjusted analysis, these differences were not found (9.6% vs. 10.0%; HR = 0.98, 95% CI = 0.93 to 1.03, p > 0.05). Inverse probability of treatment weighting- and LASSO-adjusted analyses replicated these results.

CONCLUSIONS

In this nationwide real-world data analysis of OHCA, the 30-day neurologically favorable survival did not differ between prehospital AAM and BVM after adjustment for clinical characteristics.

Bag-Valve-Mask versus Laryngeal Mask Airway Ventilation in Cardiopulmonary Resuscitation with Continuous Compressions: A Simulation Study

INTRODUCTION

The 2017 International Liaison Committee on Resuscitation (ILCOR) guideline recommends that Emergency Medical Service (EMS) providers can perform cardiopulmonary resuscitation (CPR) with synchronous or asynchronous ventilation until an advanced airway has been placed. In the current literature, limited data on CPR performed with continuous compressions and asynchronous ventilation with bag-valve-mask (BVM) are available.

STUDY OBJECTIVE

In this study, researchers aimed to compare the effectiveness of asynchronous BVM and laryngeal mask airway (LMA) ventilation during CPR with continuous chest compressions.

METHODS

Emergency medicine residents and interns were included in the study. The participants were randomly assigned to resuscitation teams with two rescuers. The cross-over simulation study was conducted on two CPR scenarios: asynchronous ventilation via BVM during a continuous chest compression and asynchronous ventilation via LMA during a continuous chest compression in cardiac arrest patient with asystole. The primary endpoints were the ventilation-related measurements.

RESULTS

A total of 92 volunteers were included in the study and 46 CPRs were performed in each group. The mean rate of ventilations of the LMA group was significantly higher than that of the BVM group (13.7 [11.7-15.7] versus 8.9 [7.5-10.3] breaths/minute; P <.001). The mean volume of ventilations of the LMA group was significantly higher than that of the BVM group (358.4 [342.3-374.4] ml versus 321.5 [303.9-339.0] ml; P = .002). The mean minute ventilation volume of the LMA group was significantly higher than that of the BVM group (4.88 [4.15-5.61] versus 2.99 [2.41-3.57] L/minute; P <.001). Ventilations exceeding the maximum volume limit occurred in two (4.3%) CPRs in the BVM group and in 11 (23.9%) CPRs in the LMA group (P = .008).

CONCLUSION

The results of this study show that asynchronous BVM ventilation with continuous chest compressions is a reliable and effective strategy during CPR under simulation conditions. The clinical impact of these findings in actual cardiac arrest patients should be evaluated with further studies at real-life scenes.

Effects of Bag Mask Ventilation and Advanced Airway Management on Adherence to Ventilation Recommendations and Chest Compression Fraction: A Prospective Randomized Simulator-Based Trial

The role of advanced airway management (AAM) in cardiopulmonary resuscitation (CPR) is currently debated as observational studies reported better outcomes after bag-mask ventilation (BMV), and the only prospective randomized trial was inconclusive. Adherence to CPR guidelines ventilation recommendations is unknown and difficult to assess in clinical trials. This study compared AAM and BMV with regard to adherence to ventilation recommendations and chest compression fractions in simulated cardiac arrests. A total of 154 teams of 3–4 physicians were randomized to perform CPR with resuscitation equipment restricting airway management to BMV only or equipment allowing for all forms of AAM. BMV teams ventilated 6 ± 6/min and AAM teams 19 ± 8/min (range 3–42/min; p < 0.0001 vs. BMV). 68/78 BMV teams and 23/71 AAM teams adhered to the ventilation recommendations (p < 0.0001). BMV teams had lower compression fractions than AAM teams (78 ± 7% vs. 86 ± 6%, p < 0.0001) resulting entirely from higher no-flow times for ventilation (9 ± 4% vs. 3 ± 3 %; p < 0.0001). Compared to BMV, AAM leads to significant hyperventilation and lower adherence to ventilation recommendations but favourable compression fractions. The cumulative effect of deviations from ventilation recommendations has the potential to blur findings in clinical trials.

Outcomes With the Use of Bag-Valve-Mask Ventilation During Out-of-hospital Cardiac Arrest in the Pragmatic Airway Resuscitation Trial

BACKGROUND

While emergency medical services (EMS) often use endotracheal intubation (ETI) or supraglottic airways (SGA), some patients receive only bag-valve-mask (BVM) ventilation during out-of-hospital cardiac arrests (OHCA). Our objective was to compare patient characteristics and outcomes for BVM ventilation to advanced airway management (AAM) in adults with OHCA.

METHODS

Using data from the Pragmatic Airway Resuscitation Trial, we identified patients receiving AAM (ETI or a SGA), BVM ventilation only (BVM-only), and BVM ventilation as a rescue after at least one failed attempt at advanced airway placement (BVM-rescue). The outcomes were return of spontaneous circulation (ROSC), 72-hour survival, survival to hospital discharge, neurologically intact survival (Modified Rankin Scale ≤ 3), and the presence of aspiration on a chest radiograph. Comparisons were made using generalized mixed-effects models while adjusting for age, sex, initial rhythm, EMS-witnessed status, bystander cardiopulmonary resuscitation, response time, study cluster, and advanced life support first on scene.

RESULTS

Of 3,004 patients enrolled, there were 282 BVM-only, 2,129 AAM, and 156 BVM-rescue patients with complete covariates. Shockable initial rhythms (34% vs. 18.6%) and EMS-witnessed arrests (21.6% vs. 11.3%) were more likely in BVM-only than AAM but similar between BVM-rescue and AAM. Compared to AAM, BVM-only patients had similar ROSC (odds ratio [OR] = 1.29, 95% confidence interval [CI] = 0.96 to 1.73), but higher 72-hour survival (OR = 1.96, 95% CI = 1.42 to 2.69), survival to discharge (OR = 4.47, 95% CI = 3.03 to 6.59), and neurologically intact survival (OR = 7.05, 95% CI = 4.40 to 11.3). Compared to AAM, BVM-rescue patients had similar ROSC (OR = 0.73, 95% CI = 0.47 to 1.12) and 72-hour survival (OR = 1.08, 95% CI = 0.66 to 1.77) but higher survival to discharge (OR = 2.15, 95% CI = 1.17 to 3.95) and neurologically intact survival (OR = 2.64, 95% CI = 1.20 to 5.81). Aspiration incidence was similar.

CONCLUSIONS

Bag-valve-mask-only ventilation is associated with improved OHCA outcomes. Despite similar rates of ROSC and 72-hour survival, BVM-rescue ventilation was associated with improved survival to discharge and neurologically intact survival compared to successful AAM.

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.