Bag-valve-mask Ventilation Research Articles

Gastric Perforation from Bag-Valve-Mask Ventilation Resulting in Tension Pneumoperitoneum and Arterial Insufficiency

We report the case of a 44-year-old woman who suffered gastric perforation after receiving bag-valve-mask (BVM) ventilation in the setting of alcohol intoxication. She had a markedly distended abdomen and cold, dusky lower extremities upon arrival to the emergency department. Imaging revealed a large volume intra-abdominal accumulation of air with compression of the aorta. Needle decompression relieved symptoms of lower extremity arterial insufficiency. However, the patient quickly decompensated and subsequent exploratory laparotomy confirmed gastric rupture. A subtotal gastrectomy was performed but the patient ultimately passed on post-operative day two due to multi-organ dysfunction. Although BVM ventilation is commonplace in both the hospital and field, there is a lack of awareness of the serious complications of abdominal air accumulation due to their rareness in the adult population. Checking for abdominal distention during resuscitation ought to be routine in all patients. Signs of arterial insufficiency accompanying abdominal distention, once confirmed by diagnostic imaging that shows extensive pneumoperitoneum, are indicators of having reached a life-threatening level of air accumulation, calling for immediate needle decompression and exploratory laparotomy.

Effects of weights applied to the apex of a bag-valve-mask and pinch strength on tidal volume: a prospective simulation study

A bag-valve-mask (BVM) is a first aid tool that can easily and quickly provide positive-pressure ventilation in patients with breathing difficulties. The most important aspect of BVM bagging is how closely the mask adheres to the patient’s face when the E–C technique is used. In particular, the greater the adhesion force at the apex of the mask, the greater the tidal volume. The purpose of this study was to investigate the effect of various weights applied to the mask’s apex and the pinch strength needed to perform the E–C technique, on tidal volume. In this prospective simulation study, quasi-experimental and equivalent time-series designs were used. A total of 72 undergraduate paramedic student from three universities were recruited using convenience sampling. The tidal volumes according to the weights (0 g, 100 g, 200 g, 300 g) applied to the apical area of the mask, handgrip strength, and pinch strength (tip pinch strength, key pinch strength, and tripod pinch strength) were measured. A linear mixed model analysis was performed. Linear mixed model analyses showed that tidal volume was significantly higher at 200 g (B = 43.38, p = 0.022) and 300 g (B = 38.74, p = 0.017) than at 0 g. Tripod pinch strength (B = 12.88, p = 0.007) had a significant effect on mask adhesion for effective BVM ventilation. Adding weight to the apical area of the mask can help maintain the E–C technique and enable effective ventilation. Future studies are required to develop specific strategies to improve the ventilation skills, which can be an important first-aid activity.

Abstract 280: Effectiveness of Bag-Valve-Mask Ventilation During Out-of-Hospital Pediatric CPR

Background: Few studies have measured ventilation during early cardiopulmonary resuscitation (CPR) before advanced airway placement. Resuscitation guidelines recommend pauses after every 15 or 30 chest compressions to deliver ventilations for children. The effectiveness of bag-valve-mask (BVM) ventilation delivered during the pause in chest compressions is unknown. Hypothesis: Lung inflation occurs infrequently with BVM ventilation during 30:2 (and 15:2) CPR. Aim: To determine the incidence of lung inflation with BVM ventilation during 15:2 or 30:2 CPR for pediatric OHCA. Methods: This is a retrospective, observational study of 63 OHCA patients, <18 years of age, with non-traumatic cardiac arrest from the Dallas-Fort Worth Center for Resuscitation Research registry. Emergency medical service rescuers provided 30:2 or 15:2 CPR with BVM ventilation and ≥ 2 min of recorded CPR. We measured bioimpedance ventilation (lung inflation) waveforms in the pauses between chest compression segments recorded through defibrillation pads. A detectable ventilation waveform had a bioimpedance amplitude ≥0.5 Ohm and duration ≥1 sec. We measured the incidence of ventilation in two pre-specified groups: patients with ventilation waveforms in <50% of pauses (Group 1) vs. those with waveforms in ≥50% of pauses (Group 2). Results: The mean duration of 30:2 or 15:2 CPR was 15(8) min prior to advanced airway placement. During this period, we identified 683 pauses in chest compressions, 386 measurable ventilations, and the median (IQR) number of ventilations was 2 (0-4). Of 20 advanced airway attempts, nine were successful.Group 1 (N=48) had a median 8 pauses and 1.5 ventilations/patient, Group 2 (N= 15) had a median 10 pauses and 12 ventilations/patient (Table). Return of spontaneous circulation for Group 1 (15%, 7/48) vs. Group 2 (33%, 5/15). Conclusion: This study shows that use of a BVM device results in infrequent lung inflation during 30:2 or 15:2 CPR in pediatric patients.

Abstract 163: Lung Inflation Occurs Infrequently In Most Patients During 30:2 CPR With Bag-Valve-Mask Ventilation

Background: Few studies have measured ventilation early in cardiopulmonary resuscitation (CPR) before advanced airway placement. In 30:2 CPR, there is a pause to give two ventilations after each round of 30 chest compressions. Recently, we developed a method to identify lung inflation (ventilation) waveforms from thoracic bioimpedance defibrillator recordings measured through defibrillator pads. Early work showed that in 75% of patients receiving bag-valve-mask (BVM) ventilation, lung inflation waveforms occurred in less than half of pauses in chest compressions during 30:2 CPR. Objective: To determine the incidence of lung inflation with BVM during 30:2 CPR in a multi-center study. Methods: Our study included adult out-of-hospital cardiac arrest patients from five sites of the Resuscitation Outcomes Consortium Trial of Continuous or Interrupted Chest Compressions during CPR. Patients had 30:2 CPR with ≥ two minutes of thoracic bioimpedance signal recorded with a defibrillator (Lifepak, Physio-control, Redmond, WA or MRx, Philips, Andover, MA). Previously, we defined a ventilation waveform as having a bioimpedance amplitude ≥0.5 Ohm (corresponding to ≥ 250 ml Vt) with a duration ≥1 sec. A valid pause was 3 sec to 15 sec. An automated program analyzed the recordings. We describe groups with ventilation waveforms in <50% or ≥50% of pauses. Results: We included 1,552 patients; mean age was 66 years, 67% were male, mean (±SD) duration of 30:2 CPR was 9.9 ±5.8 min from the start of chest compressions until advanced airway placement. During this period there was a total of 21,705 pauses in chest compressions, a median of 12 pauses in chest compressions, and a median of 5 ventilations; 56% of patients had ventilation waveforms in <50% of pauses (Group 1, N=868), and 44% had waveforms in > 50% of pauses (Group 2, N=678). The median (IQR) number of pauses in Group 1 vs. Group 2, was 12 (8, 20) vs. 12 (7, 17) and the median number of ventilations was 3 (1, 6) vs. 13 (7, 21), respectively, during 30:2 CPR. The median duration of pauses for Group 1 vs. Group 2, was 5.8s (5.0, 6.5) vs. 5.7s (5.0, 6.7). Conclusion: For most patients, this multi-center study showed that ventilation waveforms were present in less than 50% of pauses in chest compressions during 30:2 CPR with BVM ventilation.

Outcome of cardiopulmonary resuscitation with different ventilation modes in adults: A meta-analysis

BackgroundThe optimal airway management strategy for cardiac arrest remains unclear. This study aimed to compare the effects of different initial airway interventions on improving clinical outcomes based on the 2010 cardiopulmonary resuscitation (CPR) guidelines and later. MethodsWe searched PubMed, EMBASE, and the Cochrane Library for CPR articles tailored to each database from October 19, 2010, to July 31, 2021, to compare endotracheal intubation (ETI), supraglottic airway (SGA), or bag-valve-mask ventilation (BMV). The initial results and long-term results were investigated by meta-analysis. ResultsTwenty-five articles (n = 196,486) were included. The ROSC rate in the ETI group (ES = 0.49, 95% CI: 0.38–0.59) was significantly higher than that in the SGA group (ES = 0.27, 95% CI: 0.20–0.34) and BMV group (ES = 0.24, 95% CI: 0.17–0.31). The rate of ROSC upon admission to the hospital in the ETI group (ES = 0.27, 95% CI: 0.13–0.42) was significantly higher than that in the SGA group (ES = 0.18, 95% CI: 0.13–0.23) and BMV group (ES = 0.16, 95% CI: 0.10–0.22). Compared with the BMV group (ES = 0.09, 95% CI: 0.04–0.14) and the SGA group (ES = 0.08, 95% CI: 0.05–0.10), the ETI group (ES = 0.14, 95% CI: 0.10–0.17) had a higher discharge rate, but all of the groups had the same neurological outcome (ETI group [ES = 0.06, 95% CI: 0.04–0.08], BMV group [ES = 0.05, 95% CI: 0.03–0.08] and SGA group [ES = 0.04, 95% CI: 0.03–0.05]). ConclusionsOpening the airway is significantly associated with improved clinical outcomes, and the findings suggest that effective ETI based on mask ventilation should be implemented as early as possible once the patient has experienced cardiac arrest.

The impact of prehospital endotracheal intubation on mortality in traumatic brain injury

IntroductionOur study aimed to evaluate whether prehospital endotracheal intubation (ETI) affects the mortality of individuals who sustain traumatic brain injury (TBI) compared with bag-valve mask (BVM) ventilation, as well as to test the interaction effect of ETI on study outcome according to carbon dioxide level. MethodsOur retrospective study involving patients who experienced TBI between January 2019 and December 2020. The main exposure variable was the prehospital airway management technique (ETI vs. BVM) performed by emergency medical service technicians and the primary outcome was survival at hospital discharge and the secondary outcome was good functional recovery at hospital discharge and six-month survival. We performed multivariable logistic regression analysis and interaction analysis between the prehospital airway management and blood level of carbon dioxide for adjusted odds ratios (aORs) and 95% confidence intervals (CIs). ResultsOf 562 eligible patients, 79 (14.1%) underwent ETI and 483 (85.9%) underwent BVM ventilation. After adjusting for possible confounders, TBI patients in the ETI group has a significantly lower likehood of survival to discharge than those in the BVM group (aOR 0.57 (0.41–0.73). In interaction analysis, the rates of survival to discharge and 6-month survival with ETI were significantly lower only in groups with hypocarbia (AOR 0.61 [95% CI 0.49–0.72] and AOR 0.82 [95% CI 0.65–0.99], respectively). ConclusionAmong individuals who experienced severe TBI, prehospital intubation did not have a significant effect on survival outcomes and good functional recovery. Patients exhibiting hypocarbia measured on hospital arrival demonstrated lower survival outcomes in the interaction analysis.

Use of a novel pedal‐operated compressor is non‐inferior to the use of a standard hand‐compressed bag‐valve mask

BackgroundThe standard bag‐valve mask (BVM) used universally requires that a single healthcare practitioner affix the mask to the face with 1 hand while compressing a self‐inflating bag with the second hand. Studies have demonstrated that creating a 2‐handed seal (with 2 healthcare practitioners) is superior. Our study aims to assess the efficacy of a novel single‐practitioner BVM device that uses a foot pedal as the bag compressor, allowing both hands to be available for the seal to facilitate delivery of appropriate tidal volumes during single‐practitioner resuscitation.MethodsThis was a prospective, randomized, cross‐over study. Participants with various BVM ventilation experience performed 2 minutes of metronome‐guided BVM ventilation using a standard BVM and the pedal‐operated compressor on a high‐fidelity simulation mannequin. Analysis examining differences in mean tidal volume delivered was conducted using a regression model that adjusted for covariates. A secondary analysis using a series of Wilcoxon tests was conducted to compare differences in the additional out‐of‐range sensed breaths metrics to compare differences by prior BVM ventilation experience.ResultsA total of 58 subjects participated. The pedal‐operated compressor unadjusted mean tidal volume delivered was 446.5 mL (95% confidence interval [CI], 425.9–467.1) compared with 340.6 mL (95% CI, 312.2–369.0) by standard BVM (mean change, 105.9 mL [95% CI, 71.2–140.6]; P < .001). When modeling a generalized estimation equation regression model, standard BVM ventilation provided a mean difference of 105.9 mL less than pedal‐operated compressor ventilation after adjusting for covariates (P = 0.01). For the secondary outcome, the pedal‐operated compressor did have a significantly lower median number of out‐of‐range breaths (median, 3; interquartile range [IQR], 1–11.5) compared with the standard device (median, 13.5; IQR, 6–19; P < 0.001).ConclusionsUse of a novel pedal‐operated compressor may allow a single healthcare practitioner, regardless of prior experience, to deliver consistent, appropriate tidal volumes with more ease compared with the standard BVM during manual respiratory resuscitation.

Abstract 13216: Initial Survey of Respiratory Mechanics During Prehospital Bag Ventilation

Introduction: Respiratory mechanics, such as tidal volume and inspiratory pressures, affect outcome in hospitalized patients with respiratory failure. The ability to accurately measure respiratory mechanics in the prehospital setting is limited, thus the relationship between prehospital respiratory mechanics and clinical outcome is not well understood. In this feasibility study, we examined respiratory mechanics of bag-valve mask (BVM) ventilation by emergency medical services (EMS) using a novel in-line measuring device during a period when agencies switched from larger to smaller ventilation bags. Methods: This prospective cohort study included a convenience sample of adult patients who received BVM ventilation by EMS, from August 2018 to January 2020, in Bellevue, Washington. The airway monitoring device was applied by paramedics after intubation to passively record in black box mode, until termination of efforts or hospital arrival. Respiratory parameters included tidal volume, airway pressure, flow rates, end-tidal carbon dioxide, and respiratory rate. Prehospital agencies transitioned from large (1500 mL) to small (1000 mL) ventilation bags during the study period. Results: 7371 post-intubation breaths were measured in 54 patients, 32 treated for out-of-hospital cardiac arrest (OHCA) and 22 treated for non-arrest conditions, primarily respiratory etiology. EMS ventilated 19 patients with a small bag and 35 patients with a large bag. Ventilation with a smaller bag was characterized by less variability in tidal volumes and higher proportion of breaths delivered within 4-10 mL/kg of predicted body weight (Figure) (p&lt;0.05). Conclusions: Respiratory mechanics can be measured in EMS patients receiving BVM ventilation following intubation. Ventilation with a smaller bag might reduce variation in tidal volume, but further study is needed. These data provide the first evaluation of respiratory mechanics during manual ventilation provided by EMS.

Comparison between Pediatric-Sized and Adult-Sized Bag-Valve-Mask Ventilation for Achieving Appropriate Tidal Volume in Simulated Adult Out-of-Hospital Cardiac Arrest in a Moving Ambulance

Background: Previous studies proposed that ventilation with pediatric-sized bag-valve-mask (BVM) ventilation resulted in more appropriate tidal volume (Vt) in adult patients than adult-sized BVM ventilation. However, those studies were conducted in stationary, non-moving environment. The authors hypothesized that the result of BVM ventilation in this treatment setting may be different when the investigation was conducted in a moving ambulance. Objective: To compare pediatric-sized and adult-sized BVM ventilation for achieving appropriate Vt in simulated adult out-of-hospital cardiac arrest (OHCA) in a moving ambulance. Materials and Methods: The present study was a randomized crossover trial. Registered nurses (RNs) and basic emergency medical technicians (EMT-Bs) were recruited to perform resuscitation ventilation on a medical training manikin. All participants performed both the pediatric-sized at 500 cc, and the adult-sized at 1,600 cc, BVM ventilation during 30 to 2 chest compressions to ventilation ratio during simulated OHCA in a moving ambulance. Adult-sized mask was used for both scenarios. The manikin was ventilated for 10 minutes during each scenario. The percentage of appropriate Vt was compared between scenarios. The percentages of low Vt at less than 400 cc and high Vt at more than 600 cc between groups were also evaluated. Results: Fifty-two volunteers with 57.7% RNs and 42.3% EMT-Bs were included. Of those 52 volunteers, 44 had less than five years of pre-hospital ventilation experience. The mean Vt was 239.0 cc and 444.5 cc in the pediatric-sized and the adult-sized BVM groups, respectively (p&lt;0.001). Low Vt was observed in 100% of pediatric-sized BVM ventilation. In the adult-sized ventilation group, 52.1±25.6% had appropriate Vt, 11.4±18.6% had high Vt, and 36.5±29.1% had low Vt (p&lt;0.001). Conclusion: A comparison between pediatric-sized and adult-sized BVM ventilation in simulated adult OHCA in a moving ambulance demonstrated the superiority of the adult-sized BVM over the pediatric-sized BVM for achieving appropriate Vt in adult OHCA. Keywords: Bag-valve-mask ventilation; Tidal volume; Out-of-hospital cardiac arrest; Ambulance

Can bag-valve mask ventilation with positive end-expiratory pressure reduce hypoxia during intubation? A prospective, randomized, double-blind trial

BackgroundHypoxia is one of the life-threatening complications of endotracheal intubation. Supplemental oxygen and ventilation play a vital role in preventing hypoxia. Bag-valve mask (BVM) ventilation is frequently used before intubation, and its ability to improve oxygenation was recently confirmed. It is still unclear if positive end-expiratory pressure (PEEP) added to BVM ventilation can further reduce hypoxia during intubation.MethodsThis will be a prospective, randomized, double-blind trial to determine if PEEP combined with BVM ventilation can reduce the incidence of hypoxia during intubation compared with conventional BVM ventilation. The lowest oxygen saturation and incidence of complications will be compiled to verify the comparative effectiveness and safety of the two groups.DiscussionBMV ventilation with PEEP is hoped to further reduce the incidence of hypoxia during intubation.Trial registrationChinese Clinical Trial Registry ChiCTR2000035156. Registered on August 2, 2020. It had begun enrollment after passing ethical review but before registration.

ICU-free days as a more sensitive primary outcome for clinical trials in critically ill pediatric patients.

BackgroundOur objective was to assess the association between intensive care unit (ICU)‐free days and patient outcomes in pediatric prehospital care and to evaluate whether ICU‐free days is a more sensitive outcome measure for emergency medical services research in this population.MethodsThis study used data from a previous pediatric prehospital trial. The original study enrolled patients ≤12 years of age and compared bag‐valve‐mask‐ventilation (BVM) versus endotracheal intubation (ETI) during prehospital resuscitation. For the current study, we defined ICU‐free days as 30 minus the number of days in the ICU (range, 0–30 days) and assigned 0 ICU‐free days for death within 30 days. We compared ICU‐free days between the original study treatment groups (BVM vs ETI) and with the original trial outcomes of survival to hospital discharge and Pediatric Cerebral Performance Category (PCPC).ResultsMedian ICU‐free days for the BVM group (n = 404) versus ETI group (n = 416) was not statistically different: 0 ICU‐free days (interquartile range, 0–10) versus 0 (0–0), P = 0.219. Median ICU‐free days were greater for BVM group in 3 subgroups: foreign body aspiration 30 (0–30) versus 0 (0–21), P = 0.028; child maltreatment 0 (0–14.2) versus 0 (0‐0), P = 0.004; and respiratory arrest 25 (1–29) versus 7.5 (0–27.7), P = 0.015. In the original trial, neither survival nor PCPC demonstrated differences in all 3 subgroups—survival was greater with BVM for child maltreatment and respiratory arrest and favorable PCPC was greater with BVM for foreign body aspiration. Overall, in the current study, patients with more ICU‐free days also had greater survival to hospital discharge and more favorable PCPC scores.ConclusionsThis initial study of the association between ICU‐free days and patient outcomes during prehospital pediatric resuscitation appears to support the use of ICU‐free days as a clinical endpoint in this population. ICU‐free days may be more sensitive than either mortality or PCPC alone while capturing aspects of both measures.

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

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

Gastric Perforation Secondary to Bag-Valve Mask Ventilation Following Opioid Overdose.

Gastric Perforation Secondary to Bag-Valve Mask Ventilation Following Opioid Overdose.

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

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. 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. 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. 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.

Effect of tidal volume on gas exchange during rescue ventilation

Tidal volume VT required for mouth-to-mouth (MTM) and bag-valve-mask (BVM) rescue ventilation remains debatable owing to differences in physiology and end-point objectives. Analysis of gas transport may clarify minimum necessary VT and its determinants. Alveolar and arterial O2 and CO2 responses to MTM and air BVM ventilation for VT between 0.4 and 1.2 liters were computed using a model of gas exchange that incorporates inspired gas concentrations, airway dead space, cardiac output, pulmonary shunt, blood gas dissociation curves, tissue compartments, and metabolic rate. Parameters were adjusted to match published human data. Steady state arterial oxygen saturation reached plateaus at VT above 0.7 liters with MTM and 0.6 liters with air ventilation at 12 breaths per minute. Increasing shunt shifted oxygenation plateaus downward, but larger tidal volumes did not improve oxygen saturation. Carbon dioxide retention occurred at VT below 2.3 liters for MTM ventilation and 0.6 liters for air ventilation. Results establish a physiological foundation for tidal volume requirements during resuscitation.

Does the Number of Fingers on the Bag Influence Volume Delivery? A Randomized Model Study of Bag-Valve-Mask Ventilation in Infants.

We sought to compare the effectiveness of two versus five fingers used for bag-valve-mask (BVM) ventilation on effective tidal volume (VTeff) delivery in an infant resuscitation model. In a randomised cross-over study, 40 healthcare professionals ventilated a modified leak-free infant resuscitation manikin with both two and five fingers, using a self-inflating bag. The delivered and effective tidal volumes, ventilation rate, and mask leak were measured and recorded using a respiratory function monitor. We found no significant differences in the VTeff (five-finger 61.7 ± 23.9 vs. two-finger 58.8 ± 16.6 mL; p = 0.35) or ventilatory minute volume (2.71 ± 1.59 vs. 2.76 ± 1.24 L/min; p = 0.40) of both BVM ventilation techniques. However, there was an increase in the delivered tidal volume (VTdel) and mask leak when using the five-finger technique compared with the two-finger technique (VTdel 96.1 ± 19.4 vs. 87.7 ± 15.5 mL; p < 0.01; and mask leak 34.6 ± 23.0 vs. 30.0 ± 21.0%; p = 0.02). Although the five-finger technique was associated with an increased mask leak, the number of fingers used during the BVM ventilation had no effect on VTeff in an infant resuscitation model.

Abstract P-019: COMPARISON BETWEEN SYNCHRONIZED AND NON-SYNCHRONIZED VENTILATION AND BETWEEN GUIDED AND NON-GUIDED CHEST COMPRESSIONS DURING RESUSCITATION IN A PEDIATRIC ANIMAL MODEL AFTER ASPHYXIAL CARDIAC ARREST

Aims & Objectives: To compare between synchronized and non-synchronized bag-valve-mask ventilation (BVMV) with chest compression and between guided and non-guided chest compression (CC) with a real-time feedback-device in a pediatric animal model of asphyxial cardiac arrest (CA). Methods Experimental model of asphyxial CA in piglets. Piglets were randomized for cardiopulmonary resuscitation (CPR) into four groups according to BVMV (synchronized and non-synchronized with CC) and to CC feedback (with and without CC feedback accelerometer, ZOLL®): Group A, guided-CC and synchronized ventilation; B, guided-CC and non-synchronized ventilation; C, non-guided CC and synchronized ventilation; D, non-guided CC and non-synchronized ventilation. Systolic, diastolic and mean blood pressure (SBP, DBP and MBP), and return of spontaneous circulation (ROSC) were compared between all groups. Results 43 piglets (median weight 11.8 kg) were studied. Twenty (46.5%) achieved ROSC: group A 36.4%, group B 75%, group C 30% and group D 46.5% (p=0.13). Survival rates was higher in group B than in A+C+D (75% vs 35.5%, p=0.02). ROSC was higher with non-synchronized ventilation (B+D 59.1% vs A+C 33.3%, p=0.091) and with guided-CC (A+B 56.5% vs C+D 35%, p=0.16). BP after 3 minutes of resuscitation are shown in Table 1. Non-synchronized ventilation was associated with higher SBP and MBP. No significant differences were found regarding blood pressures between group B and the rest of groups.Conclusions In a pediatric animal model of CA, non-synchronized ventilation and guided CPR obtained significantly higher survival rates. Better SBP and MBP after 3 minutes of resuscitation were achieved with non-synchronized ventilation.

LO38: Does spaced instructional design result in improved retention of pediatric resuscitation skills? A randomized education study

Introduction: Survival from cardiac arrest has been linked to the quality of resuscitation care. Unfortunately, healthcare providers frequently underperform in these critical scenarios, with a well-documented deterioration in skills weeks to months following advanced life support courses. Improving initial training and preventing decay in knowledge and skills are a priority in resuscitation education. The spacing effect has repeatedly been shown to have an impact on learning and retention. Despite its potential advantages, the spacing effect has seldom been applied to organized education training or complex motor skill learning where it has the potential to make a significant impact. The purpose of this study was to determine if a resuscitation course taught in a spaced format compared to the usual massed instruction results in improved retention of procedural skills. Methods: EMS providers (Paramedics and Emergency Medical Technicians (EMT)) were block randomized to receive a Pediatric Advanced Life Support (PALS) course in either a spaced format (four 210-minute weekly sessions) or a massed format (two sequential 7-hour days). Blinded observers used expert-developed 4-point global rating scales to assess video recordings of each learner performing various resuscitation skills before, after and 3-months following course completion. Primary outcomes were performance on infant bag-valve-mask ventilation (BVMV), intraosseous (IO) insertion, infant intubation, infant and adult chest compressions. Results: Forty-eight of 50 participants completed the study protocol (26 spaced and 22 massed). There was no significant difference between the two groups on testing before and immediately after the course. 3-months following course completion participants in the spaced cohort scored higher overall for BVMV (2.2 ± 0.13 versus 1.8 ± 0.14, p=0.012) without statistically significant difference in scores for IO insertion (3.0 ± 0.13 versus 2.7± 0.13, p= 0.052), intubation (2.7± 0.13 versus 2.5 ± 0.14, p=0.249), infant compressions (2.5± 0.28 versus 2.5± 0.31, p=0.831) and adult compressions (2.3± 0.24 versus 2.2± 0.26, p=0.728) Conclusion: Procedural skills taught in a spaced format result in at least as good learning as the traditional massed format; more complex skills taught in a spaced format may result in better long term retention when compared to traditional massed training as there was a clear difference in BVMV and trend toward a difference in IO insertion.

Impact of prehospital airway management on combat mortality

IntroductionAnalysis of modern military conflicts suggests that airway compromise remains the second leading cause of preventable death of combat fatalities. This study compares outcomes of combat casualties that received prehospital airway interventions, specifically bag valve mask (BVM) ventilation, cricothyrotomy, and supraglottic airway (SGA) placement. The goal is to compare the effectiveness of airway management strategies used in the military pre-hospital setting. MethodsThis retrospective chart review of 1267 US Army medical evacuation patient care records, compared outcomes of casualties that received prehospital advanced airway interventions. The patients consisted of US military injured in Operation Enduring Freedom January 2011–March 2014. Compared outcomes consisted of vent-, ICU-, and hospital-free days. ResultsThose with SGA placement experienced fewer vent-free days, ICU-free days, and hospital-free days compared to BVM and cricothyrotomy patients. The groups did not significantly differ in rates of 30-day survival. The odds for survival were not significantly higher for BVM versus SGA patients (OR 1.5, 95% CI 0.2–9.8), cricothyrotomy versus SGA patients (OR 3.9, 95% CI 0.6–24.9), or cricothyrotomy versus BVM patients (OR 2.7, 95% CI 0.5–13.8) in a logistic regression model adjusting for GCS. ConclusionThis study supports prehospital BVM ventilation as a possible alternative to cricothyrotomy as there was no difference in measured outcomes between the groups. It further cautions against SGA use in the prehospital combat setting due to higher morbidity demonstrated by fewer ventilator, hospital, and ICU free days than those receiving cricothyrotomy or BVM ventilation. There was no difference in 30-day survival between the groups.

Bag Valve Mask Ventilation as a Perceptual-Cognitive Skill.

Objective This study used a high-fidelity infant mannequin to examine the relationship between the quality of bag valve mask ventilation (BVMV) and how providers of varying levels of experience use visual feedback (e.g., electronic vital signs) to guide their performance. Background BVMV is a common and critical procedure for managing pediatric respiratory emergencies. However, providers do not consistently deliver effective BVMV. Efforts to improve BVMV have ignored the question of how providers effectively use feedback often available during BVMV. Method Six expert and six novice respiratory therapists completed two simulations of an infant requiring BVMV. In one, the technology failed to display SpO2, an important but somewhat redundant visual cue. Eye movements, verbal reports, and ventilation rate (in breaths per minute) were measured in each simulation. Results Regardless of SpO2 availability, eye movements and verbal reports suggested that novices depended strongly on electronic vital signs and when SpO2 was absent ventilated at a faster rate (exceeding the recommended range of ventilation rates) than when SpO2 was present. Experts' ventilation rates were comparable and within the recommended range in both conditions. When SpO2 was absent, experts emphasized information from direct observation of the patient that novices neglected. Conclusion Individual differences in the use of feedback during BVMV contribute to the quality of BVMV. This work bears on the theoretical discussions involving the use of automation and nontechnological cues to guide performance. Application These results have the potential to expand the current understanding of factors underlying effective BVMV with implications for training novice providers.