Bag-valve Ventilation Research Articles

Oxygenation and ventilation during prolonged experimental cardiopulmonary resuscitation with either continuous or 30:2 compression-to-ventilation ratios together with 10 cmH20 positive end-expiratory pressure

BackgroundIn refractory out-of-hospital cardiac arrest, the patient is commonly transported to hospital with mechanical continuous chest compressions (CCC). Limited data are available on the optimal ventilation strategy. Accordingly, we compared arterial oxygenation and haemodynamics during manual asynchronous continuous ventilation and compressions with a 30:2 compression-to-ventilation ratio together with the use of 10 cmH2O positive end-expiratory pressure (PEEP).MethodsIntubated and anaesthetized landrace pigs with electrically induced ventricular fibrillation were left untreated for 5 min (n = 31, weight ca. 55 kg), after which they were randomized to either the CCC group or the 30:2 group with the the LUCAS® 2 piston device and bag-valve ventilation with 100% oxygen targeting a tidal volume of 8 ml/kg with a PEEP of 10 cmH2O for 35 min. Arterial blood samples were analysed every 5 min, vital signs, near-infrared spectroscopy and electrical impedance tomography (EIT) were measured continuously, and post-mortem CT scans of the lungs were obtained.ResultsThe arterial blood values (median + interquartile range) at the 30-min time point were as follows: PaO2: 180 (86–302) mmHg for the 30:2 group; 70 (49–358) mmHg for the CCC group; PaCO2: 41 (29–53) mmHg for the 30:2 group; 44 (21–67) mmHg for the CCC group; and lactate: 12.8 (10.4–15.5) mmol/l for the 30:2 group; 14.7 (11.8–16.1) mmol/l for the CCC group. The differences were not statistically significant. In linear mixed models, there were no significant differences between the groups. The mean arterial pressures from the femoral artery, end-tidal CO2, distributions of ventilation from EIT and mean aeration of lung tissue in post-mortem CTs were similar between the groups. Eight pneumothoraces occurred in the CCC group and 2 in the 30:2 group, a statistically significant difference (p = 0.04).ConclusionsThe 30:2 and CCC protocols with a PEEP of 10 cmH2O resulted in similar gas exchange and vital sign outcomes in an experimental model of prolonged cardiac arrest with mechanical compressions, but the CCC protocol resulted in more post-mortem pneumothoraces.

A retrospective comparison of mechanical cardio-pulmonary ventilation and manual bag valve ventilation in non-traumatic out-of-hospital cardiac arrests: A study from the Belgian cardiac arrest registry

BackgroundThe optimal ventilation modalities to manage out-of-hospital cardiac arrest (OHCA) remain debated. A specific pressure mode called cardio-pulmonary ventilation (CPV) may be used instead of manual bag ventilation (MBV). We sought to analyse the association between mechanical CPV and return of spontaneous circulation (ROSC) in non-traumatic OHCA. MethodsMBV and CPV were retrospectively identified in patients with non-traumatic OHCA from the Belgian Cardiac Arrest Registry. We used a two-level mixed-effects multivariable logistic regression analysis to determine the association between the ventilation modalities and outcomes. The primary and secondary study criteria were ROSC and survival with a Cerebral Performance Category (CPC) score of 1 or 2 at 30 days. Age, sex, initial rhythm, no-flow duration, low-flow duration, OHCA location, use of a mechanical chest compression device and Rankin status before arrest were used as covariables. ResultsBetween January 2017 and December 2021, 2566 patients with OHCA who fulfilled the inclusion criteria were included. 298 (11.6%) patients were mechanically ventilated with CPV whereas 2268 were manually ventilated. The use of CPV was associated with greater probability of ROSC both in the unadjusted (odds ratio: 1.28, 95% confidence interval [CI]: 1.01–1.63; p = 0.043) and adjusted analyses (adjusted odds ratio [aOR]: 2.16, 95%CI 1.37–3.41; p = 0.001) but not with a lower CPC score (aOR: 1.44, 95%CI 0.72–2.89; p = 0.31). ConclusionsCompared with MBV, CPV was associated with an increased risk of ROSC but not with improved an CPC score in patients with OHCA. Prospective randomised trials are needed to challenge these results.

374 Comparison of Arterial Oxygen Levels of Mechanical Ventilators Versus Bag-Valve Ventilation During Cardiopulmonary Resuscitation: A Randomized Trial

374 Comparison of Arterial Oxygen Levels of Mechanical Ventilators Versus Bag-Valve Ventilation During Cardiopulmonary Resuscitation: A Randomized Trial

The effects of mechanical versus bag-valve ventilation on gas exchange during cardiopulmonary resuscitation in emergency department patients: A randomized controlled trial (CPR-VENT)

IntroductionEffective ventilation is crucial for successful cardiopulmonary resuscitation (CPR). Previous studies indicate that higher arterial oxygen levels (PaO2) during CPR increase the chances of successful resuscitation. However, the advantages of mechanical ventilators over bag-valve ventilation for achieving optimal PaO2 during CPR remain uncertain. MethodWe conducted a randomized trial involving non-traumatic adult cardiac arrest patients who received CPR in the ED. After intubation, patients were randomly assigned to ventilate with a mechanical ventilator (MV) or bag valve ventilation (BV). In MV group, ventilation settings were: breath rate 10/minute, tidal volume 6–7 ml/kg, inspiratory time 1 second, positive end-expiratory pressure 0 cm water, inspiratory oxygen fraction (FiO2) 100%. The primary outcome was to compare the difference in PaO2 from arterial blood gases (ABG) obtained 4–10 minutes later during CPR between both groups. ResultsSixty patients were randomized (30 in each group). The study population consisted of: 57% male, median age 62 years, 37% received bystander CPR, and 20% had an initial shockable rhythm. Median time from arrest to intubation was 24 minutes. The median PaO2 was not significantly different in the BV compared to MV [36.5 mmHg (14.0–70.0) vs. 29.0 mmHg (15.0–70.0), P = 0.879]. Other ABG parameters and rates of return of spontaneous circulation and survival were not different. ConclusionsIn ED patients with refractory cardiac arrest, arterial oxygen levels during CPR were comparable between patients ventilated with MV and BV. Mechanical ventilation is at least feasible and safe during CPR in intubated cardiac arrest patients.

Use of a Portable Mechanical Ventilator during Cardiopulmonary Resuscitation is Feasible, Improves Respiratory Parameters, and Prevents the Decrease of Dynamic Lung Compliance.

For practical and protective ventilation during cardiopulmonary resuscitation (CPR), a 150-grams mechanical ventilator (VLP2000E) that limits peak inspiratory pressure (PIP) during simultaneous ventilation with chest compressions was developed. To evaluate the feasibility of VLP2000E ventilation during CPR and to compare monitored parameters versus bag-valve ventilation. A randomized experimental study with 10 intubated pigs per group. After seven minutes of ventricular fibrillation, 2-minute CPR cycles were delivered. All animals were placed on VLP2000E after achieving return of spontaneous circulation (ROSC). Bag-valve and VLP2000E groups had similar ROSC rate (60% vs. 50%, respectively) and arterial oxygen saturation in most CPR cycles, different baseline tidal volume [0.764 (0.068) vs. 0.591 (0.123) L, p = 0.0309, respectively] and, in 14 cycles, different PIP [52 (9) vs. 39 (5) cm H2O, respectively], tidal volume [0.635 (0.172) vs. 0.306 (0.129) L], ETCO2[14 (8) vs. 27 (9) mm Hg], and peak inspiratory flow [0.878 (0.234) vs. 0.533 (0.105) L/s], all p < 0.0001. Dynamic lung compliance (≥ 0.025 L/cm H2O) decreased after ROSC in bag-valve group but was maintained in VLP2000E group [0.019 (0.006) vs. 0.024 (0.008) L/cm H2O, p = 0.0003]. VLP2000E ventilation during CPR is feasible and equivalent to bag-valve ventilation in ROSC rate and arterial oxygen saturation. It produces better respiratory parameters, with lower airway pressure and tidal volume. VLP2000E ventilation also prevents the significant decrease of dynamic lung compliance observed after bag-valve ventilation. Further preclinical studies confirming these findings would be interesting.

Ventilation during continuous compressions or at 30:2 compression-to-ventilation ratio results in similar arterial oxygen and carbon dioxide levels in an experimental model of prolonged cardiac arrest

BackgroundIn refractory out-of-hospital cardiac arrest, transportation to hospital with continuous chest compressions (CCC) from a chest compression device and ventilation with 100% oxygen through an advanced airway is common practice. Despite this, many patients are hypoxic and hypercapnic on arrival, possibly related to suboptimal ventilation due to the counterpressure caused by the CCC. We hypothesized that a compression/ventilation ratio of 30:2 would provide better ventilation and gas exchange compared to asynchronous CCC during prolonged experimental cardiopulmonary resuscitation (CPR).MethodsWe randomized 30 anaesthetized domestic swine (weight approximately 50 kg) with electrically induced ventricular fibrillation to the CCC or 30:2 group and bag-valve ventilation with a fraction of inspired oxygen (FiO2) of 100%. We started CPR after a 5-min no-flow period and continued until 40 min from the induction of ventricular fibrillation. Chest compressions were performed with a Stryker Medical LUCAS® 2 mechanical chest compression device. We collected arterial blood gas samples every 5 min during the CPR, measured ventilation distribution during the CPR using electrical impedance tomography (EIT) and analysed post-mortem computed tomography (CT) scans for differences in lung aeration status.ResultsThe median (interquartile range [IQR]) partial pressure of oxygen (PaO2) at 30 min was 110 (52–117) mmHg for the 30:2 group and 70 (40–171) mmHg for the CCC group. The median (IQR) partial pressure of carbon dioxide (PaCO2) at 30 min was 70 (45–85) mmHg for the 30:2 group and 68 (42–84) mmHg for the CCC group. No statistically significant differences between the groups in PaO2 (p = 0.40), PaCO2 (p = 0.79), lactate (p = 0.37), mean arterial pressure (MAP) (p = 0.47) or EtCO2 (p = 0.19) analysed with a linear mixed model were found. We found a deteriorating trend in PaO2, EtCO2 and MAP and rising PaCO2 and lactate levels through the intervention. There were no differences between the groups in the distribution of ventilation in the EIT data or the post-mortem CT findings.ConclusionsThe 30:2 and CCC protocols resulted in similar gas exchange and lung pathology in an experimental prolonged mechanical CPR model.

Contrived Breathing Circuit Connection for Emergency Percutaneous Transtracheal Ventilation by Needle Cricothyrotomy in the Field.

Surgical airway approaches are, at times, last resort options in difficult airway management. In Special Operations these interventions confront distorted anatomy from combat trauma, extreme conditions, and may be performed by non-medically trained personnel. Under these circumstances, needle cricothyroidotomy using a large bore intravenous catheter can be considered. A small syringe connected to the needle can confirm transtracheal placement through air aspiration before passing the angiocatheter over the needle. Button activated retracting needles should be avoided for this when possible. We recommend a 3-mL Luer-lock syringe because a small syringe is better suited for generating pressure and once the catheter is in the trachea, this same syringe can be connected to bag valve ventilation by replacing its plunger with a connector from a 6.5-, 7-, or 7.5-mm endotracheal tube. Adding these small and light high-yield items to the Tactical Combat Casualty Care medic inventory should be considered in future revisions.

Tidal volume measurements via transthoracic impedance waveform characteristics: The effect of age, body mass index and gender. A single centre interventional study

Background and aimMeasuring tidal volumes (TV) during bag-valve ventilation is challenging in the clinical setting. The ventilation waveform amplitude of the transthoracic impedance (TTI-amplitude) correlates well with TV for an individual, but poorer between patients. We hypothesized that TV to TTI-amplitude relations could be improved when adjusted for morphometric variables like body mass index (BMI), gender or age, and that TTI-amplitude cut-offs for ventilations with adequate TV (>400ml) could be established. Materials and methodsTwenty-one consenting adults (9 female, and 9 overall overweight) during positive pressure ventilation in anaesthesia before scheduled surgery were included. Seventeen ventilator modes were used (⩾ five breaths per mode) to adjust different TVs (150–800 ml), ventilation frequencies (10–30 min−1) and insufflation times (0.5–3.5 s). TTI from the defibrillation pads was filtered to obtain ventilation TTI-amplitudes. Linear regression models were fitted between target and explanatory variables, and compared (coefficient of determination, R2). ResultsThe TV to TTI-amplitude slope was 1.39 Ω/l (R2=0.52), with significant differences (p<0.05) between male/female (1.04 Ω/l vs 1.84 Ω/l) and normal/overweight subjects (1.65 Ω/l vs 1.04 Ω/l). The median (interquartile range) TTI-amplitude cut-off for adequate TV was 0.51 Ω(0.14–1.20) with significant differences between males and females (0.58 Ω/0.39 Ω), and normal and overweight subjects (0.52 Ω/0.46 Ω). The TV to TTI-amplitude model improved (R2=0.66) when BMI, age and gender were included. ConclusionsTTI-amplitude to TV relations were established and cut-offs for ventilations with adequate TV determined. Patient morphometric variables related to gender, age and BMI explain part of the variability in the measurements.

P038: A procedural skills needs assessment targeting physicians providing emergency department coverage in rural Newfoundland and Labrador

Introduction: Maintaining competence in high-acuity low-occurrence (HALO) procedures is often difficult due to their infrequent occurrence. While simulation is a valuable tool to hone skills, providing effective simulation-based education (SBE) to learners outside academic centers can be challenging. Utilizing a mobile tele-simulation unit (MTU) with expert instruction from a geographically separated mentor could prove a valuable approach to overcoming barriers in this setting. However, to maximize benefit and buy-in, the training modules developed for this unique delivery method must align with the needs of those practicing in rural settings. Objectives: - To evaluate the procedural skills training needs of emergency medicine (EM) physicians in rural Newfoundland and Labrador (NL) - To inform the development of simulation modules designed for use in a MTU Methods: A web-based needs assessment was distributed to physicians registered with the NL Medical Association, working in rural locations, and having EM listed as their primary specialty. Participants evaluated their comfort, performance frequency and desire to have further training for 12 HALO procedures. Two EM physicians selected these from a broader list of core procedural skill competencies for CCFP-EM residents at Memorial University. Participants were also able to suggest other procedures that might benefit from SBE. Results: The data collection occurred for 8 weeks with a 68% response rate (N = 22). No respondents had formal EM training outside of exposure in family medicine residency. 60% had 10+ years practicing EM. Chest tube insertion (100%), difficult intubation (92.3%) and surgical airway (92.3%) were the procedures that most respondents felt required more SBE. In practice, they most often performed bag-valve ventilation, splint application and procedural sedation (&amp;gt;10 per year). Additional procedures felt to require SBE were central venous line placement and trauma assessment. Opportunities to participate in SBE were limited (66.7%-less than annually). Despite this, most participants agreed SBE would be a significant benefit if accessible (93.3%). The greatest barriers to SBE included lack of equipment, rural location, and time necessary for travel to larger centres. Conclusion: The provision of medical care in rural settings can be particularly challenging when HALO procedures must be performed. Unique delivery methods of SBE targeted to the needs of rural practitioners may help bridge gaps in knowledge and technical skills.

Effectiveness of Manual Ventilation in Intubated Helicopter Emergency Services–Transported Trauma Patients

BackgroundHelicopter Emergency Medical Services agencies frequently transport intubated patients to definitive care. No evidence exists to determine the type of ventilation in this population. Practice varies amongst programs from bag-valve-mask to mechanical ventilation. Study ObjectiveEvaluate the effectiveness of bag-valve ventilation in intubated trauma patients. We hypothesized manual ventilation provides adequate support to maintain physiologic ETCO2. MethodsFrom June to December 2015, twenty patients were enrolled in this prospective, observational study. Included were endotracheally intubated trauma patients transported by this HEMS program. Excluded were interfacility transports, non-scene calls, and patients with supraglottic devices. ETCO2 was recorded every 30 seconds during the flight. As a descriptive pilot study, power was not considered. Results20 patients provided over 500 cumulative minutes of manual ventilation data. The percentage of cumulative time spent with adequate oxygen saturations was 83.6%. The percentage of cumulative time spent with adequate ETCO2 was 48.7%, with 34.6% of time spent under and 16.7% above this range. ConclusionManual ventilation maintained a physiologic ETCO2 only 16.7% of the time. Significant variability existed, resulting in intermittent hypoxia and hyperventilation. Prior research linked such events to increased morbidity and mortality. Further studies are warranted to compare manual against mechanically ventilated patients.

Effectiveness of positive pressure ventilation during newborn care unit evacuation

ObjectiveAssess the utility of high fidelity simulation in understanding effectiveness of bag-valve ventilation in a simulated newborn intensive care unit vertical evacuation. ParticipantsA total of 70 participants, (13 teams of 4–6 staff) including physicians, nurses, respiratory therapists and other support personnel participated in a 90-min evacuation sessions. MethodsTwo wireless high-fidelity newborn mannequins (Gaumand ScientificR) provided real-time data of ventilation support during a NICU evacuation exercise. Trained evaluators also recorded data related to performance. Following the exercises, the simulator data were downloaded and analyzed for rate and consistency of respirations. ResultsUsing the data from the simulators and evaluator comments, it was found the infants received proper airway management during the evacuation only 58% of the time. This study highlights the need for ongoing training for NICU staff around safe, effective, coordinated, and timely care of these fragile newborns in the event of an evacuation.

Evaluation of six different airway devices regarding regurgitation and pulmonary aspiration during cardio-pulmonary resuscitation (CPR) – A human cadaver pilot study

BackgroundChest compressions and ventilation are lifesaving tasks during cardio-pulmonary resuscitation (CPR). Besides oxygenation, endotracheal intubation (ETI) during CPR is performed to avoid aspiration of gastric contents. If intubation is difficult or impossible, supraglottic airway devices are utilized. We tested six different airway devices regarding their potential to protect against regurgitation and aspiration during CPR in a randomized experimental human cadaver study. MethodsFive-hundred ml of 0.01% methylene-blue-solution were instilled into the stomach of 30 adult human cadavers via an oro-gastric tube. The cadavers were then randomly assigned to one of six groups, resulting in 5 cadavers in each group. Airway management was performed with either bag-valve ventilation, Laryngeal Tube, EasyTube, Laryngeal Mask (Classic), I-Gel, or ETI. Thereafter 5min of CPR were performed according to the 2010 Guidelines of the European Resuscitation Council. Pulmonary aspiration was defined as the presence of methylene-blue-solution below the vocal cords or the ETI cuff as assessed by fiber-optic bronchoscopy. ResultsThirty cadavers were included (14 females, 16 males). Aspiration was detected in three out of five cadavers receiving bag-valve ventilation and in two out of five intubated with LMA or I-Gel. In cadavers intubated with the LT, aspiration occurred in one out of five cases. No aspiration could be detected in cadavers intubated with ETI and EasyTube. ConclusionThis study provides experimental evidence that, during CPR, ETI offers superior protection against regurgitation and pulmonary aspiration of gastric contents than supraglottic airway devices or bag-valve ventilation.

Prehospital tidal volume influences hospital tidal volume: A cohort study

PurposeThe purposes of the study are to describe current practice of ventilation in a modern air medical system and to measure the association of ventilation strategy with subsequent ventilator care and acute respiratory distress syndrome (ARDS). Materials and methodsRetrospective observational cohort study of intubated adult patients (n = 235) transported by a university-affiliated air medical transport service to a 711-bed tertiary academic center between July 2011 and May 2013. Low tidal volume ventilation was defined as tidal volumes less than or equal to 8 mL/kg predicted body weight. Multivariable regression was used to measure the association between prehospital tidal volume, hospital ventilation strategy, and ARDS. ResultsMost patients (57%) were ventilated solely with bag valve ventilation during transport. Mean tidal volume of mechanically ventilated patients was 8.6 mL/kg predicted body weight (SD, 0.2 mL/kg). Low tidal volume ventilation was used in 13% of patients. Patients receiving low tidal volume ventilation during air medical transport were more likely to receive low tidal volume ventilation in the emergency department (P < .001) and intensive care unit (P = .015). Acute respiratory distress syndrome was not associated with prehospital tidal volume (P = .840). ConclusionsLow tidal volume ventilation was rare during air medical transport. Air transport ventilation strategy influenced subsequent ventilation but was not associated with ARDS.

The contribution of on-call, volunteer first responders to mass-casualty terrorist attacks in Israel.

To describe the contributions of on-call, volunteer first responders to mass-casualty terrorist attacks in Israel during the Second Intifada. Descriptive study evaluating data obtained from postevent debriefings after 15 terrorist attacks in Israel between 2001 and 2004. An average of 7.9 deaths (median 7.0, interquartile range [IQR] 2.5-12.5) and 53.8 injuries (median 50.0, IQR 34.0-62.0) occurred in each of these attacks. The average number of volunteers responding to each event was 50.3 (median 43.0, IQR 27.5-55.5). The volunteers were involved in extricating victims from imminent danger, and performing emergent tasks such as bag-valve ventilation, tourniquet application, and intravenous line insertion. They were also integral to the rapid evacuation of casualties from the scene. On-call, volunteer first responders are an integral part of Israel's emergency medical response to mass-casualty terrorist attacks. This system may be used as a model for the development of similar services worldwide.

49 Lung Protective Ventilation is Uncommon During Aeromedical Transport: An Observational Study

Mechanical ventilation is common during aeromedical transport, and emerging data suggests that routine application of low-tidal volume lung protective ventilation may decrease complications of critical illness. This study was designed to describe mechanical ventilation practices for intubated patients transported by air ambulance and to assess the effect of mechanical ventilation strategy on clinical outcomes. Our hypotheses were (1) lung protective ventilation would be uncommon in the out-of-hospital setting, (2) out-of-hospital ventilation practices would influence initial ventilator management in the hospital, and (3) non-lung protective ventilation would increase the incidence of acute respiratory distress syndrome (ARDS). Retrospective, observational cohort study of all adult patients transported by a university-affiliated aeromedical transport service to a 711-bed tertiary academic medical center (July 2011 to May 2013). Patients were excluded for (1) death within 72 hours of hospital arrival or (2) admission to an outside hospital prior to transfer. Data was collected on ventilator settings and clinical outcomes from the electronic medical record. Univariate descriptive analyses were performed and linear regression was used to test the hypothesis that hospital ventilation strategy was influenced by out-of-hospital ventilation settings. The association between lung protective ventilation and clinical outcomes was measured with a logistic regression model. Lung protective ventilation was defined a priori as ≤ 8 mL/kg predicted body weight (PBW). The Institutional Review Board approved the study under waiver of informed consent. A total of 235 patients were included in the analysis. The majority of patients (57%) were ventilated solely with bag-valve ventilation during transport. The mean tidal volume of mechanically ventilated patients was 8.6 mL/kg PBW (SD 1.7 ml/kg PBW). Lung-protective ventilation was used in 13% of patients (n= 31). Patients receiving non-protective ventilation during aeromedical transport were significantly more likely to be exposed to non-protective ventilation in the emergency department (P<0.001) and intensive care unit (P=0.015). Out-of-hospital lung-protective ventilation was associated with a decrease in mechanical ventilation days (2.1 versus 3.6 day, P=0.027), but there was no association with the incidence of ARDS, length of stay, or mortality. Low tidal volume ventilation was rare during aeromedical transport and was associated with a “therapeutic momentum” of non-lung protective ventilation during early in-hospital care. Prehospital tidal volumes were associated with a decrease in mechanical ventilation days, but not associated with development of ARDS or mortality. The out-of-hospital aeromedical environment offers a unique opportunity to study the impact of early prophylactic therapies on complications of critical illness, and further study is needed to better characterize the role of lung protective ventilation on ARDS prevention.

Analysis of prehospital endotracheal intubation performed by emergency physicians: retrospective survey of a single emergency medical center in Japan

Advanced airway management in the prehospital setting is a serious issue in Japan because emergency medical technicians are not authorized to perform such management, whereas physicians-who are authorized to perform advanced airway management-do not usually engage in prehospital emergency medical activity. The purpose of this investigation was to investigate the success rate for endotracheal intubation (ETI) procedures and other methods of airway management employed by physicians in the prehospital setting in a single institution, as well as to examine the risk factors associated with difficult or failed endotracheal intubation (D/F ETI). We performed a retrospective survey of patients treated in the prehospital setting by emergency physicians of the Hyogo Emergency Medical Center from 2004 to 2011. Patients were divided into two groups: a cardiopulmonary arrest (CPA) group and a non-CPA group. Data on cases of D/F ETI were obtained, and risk factors for these two groups were identified using univariate and statistical analysis. During the investigation period, ETI was attempted in the prehospital setting on 742 eligible patients; in 30 (4.04%) of these cases, the attempts at ETI proved difficult or failed. Of those 30 patients, 13 patients received a surgical airway (attempts to provide a surgical airway failed in two patients), a blind ETI was performed in four, a video-assisted airway device was used in another four, and esophageal intubation was performed in four patients. Bag-valve ventilation alone was performed in one patient. The incidence of D/F ETI was higher in the non-CPA group than in the CPA group (6.27 vs. 2.63%: p<0.05). Facial or neck injury was a risk factor for D/F ETI in the prehospital setting in the CPA group (odds ratio 7.855; 95% CI 1.754-36.293: p=0.042). On the other hand, no risk factors for D/F ETI in the prehospital setting in the non-CPA group were identified. The success rate for ETI performed by physicians in the prehospital setting at a single emergency medical center was high, and the incidence of D/F ETI was 4.31%. The success rate for ETI in the CPA group was greater than that in the non-CPA group.

Lessons learned from airway pressure release ventilation

The aim of this article is to review a single institution's experience with airway pressure release ventilation (APRV) with respect to safety, complications, and efficacy at correcting hypercarbia and hypoxemia. Patients transitioned from either volume- or pressure-targeted ventilation to APRV in a university hospital surgical intensive care unit were retrospectively reviewed. Patients whose ventilator strategy started with APRV were excluded. Abstracted data included age, sex, diagnosis, ventilation parameters, indication for altering the ventilator strategy, laboratory values, and ventilator-associated complications. Data before and after transitioning to APRV were compared using a two-tailed unpaired t test or χ2 test as appropriate; significance assumed for p ≤ 0.05. Patient mix (n = 38) was 43% trauma, 32% sepsis, 8% cardiac surgery, 12% vascular surgery, and 5% other. Transitioning to APRV was undertaken most often for hypoxemia (88%) and less frequently for hypercarbia (12%). The mean time to correct hypoxemia (SA(O2) >92%) was 7 minutes ± 4 minutes, while the mean time to correct P(CO2) (P(CO2) ≤40 mm Hg) was 42 minutes ± 7 minutes. The mean time to maximal CO2 clearance was 66 minutes ± 12 minutes. The mean minute ventilation decreased on APRV by 3.3 L/min ± 0.9 L/min but achieved superior CO2 clearance and oxygenation. The mean time to FIO2 ≤0.6 was 5.2 hours ± 0.9 hours. Four of the 38 patients developed a pneumothorax. Ninety-seven percent of patients on APRV who were transported out of the intensive care unit using bag-valve ventilation (with appropriate positive end-expiratory pressure valve settings) with P(high) ≥20 cm H2O developed hypoxemia within 5 minutes. Hundred percent of patients with a P(high) ≤20 cm H2O were safely hand ventilated during transport without developing hypoxemia. APRV is a safe mode of ventilation for hypoxemic or hypercarbic respiratory failure. Improvements in PO2 and PCO2 are achieved at lower minute ventilations than with volume- or pressure-targeted modes. III.

Performance and skill retention of intubation by paramedics using seven different airway devices—A manikin study

Introduction Endotracheal intubation (ETI) is the most widespread method for emergency airway management. Several studies reported that ETI requires considerable skill and experience and if performed incorrectly, may result in serious adverse events. Unrecognized tube misplacement or oesophageal intubation is associated with high prehospital morbidity. This study investigates the usability of supraglottic airway devices compared to ETI and the skill retention of 41 previously inexperienced paramedics following training using a manikin model. Methods 41 paramedics participated in this study. None had prior experience in airway management, apart from bag-valve ventilation. After a standardised audio-visual lecture lasting 45 min, the paramedics participated in a practical demonstration using the advanced patient simulator SimMan ® (Laerdal Medical, Stavanger, Norway). Afterwards, paramedics were instructed to perform airway-management using seven different techniques to secure the airway (ETI, Laryngeal mask unique [LMA], Proseal, Laryngeal tube disposable [LT-D ®], I-Gel ®, Combitube ®, and EasyTube ®) following a randomized sequence. Participants underwent reassessment after 3 months without any further training or practice in airway-management. Results During the initial training session, ETI was successfully performed in 78% of cases, while 3 months later the success rate was 58%. For the supraglottic airway devices, five out of six were successfully used by all paramedics at both time points, the exception being Proseal ®. Our data show successful skill retention (success rate: 100%) after 3 months for five out of six supraglottic airway devices. Time to ventilation (T3) was significantly less for LMA, LT-D ® and I-Gel ® at all time points compared to ETI. Conclusion ETI performed by inexperienced paramedics is associated with a low success rate. In contrast, supraglottic airway devices like LMA, LT-D ®, I-Gel ®, Combitube ® and EasyTube ® are fast, safe and easy-to-use. Within the limitations of a manikin-study, this study suggests that inexperienced medical staff might benefit from using supraglottic airway devices for emergency airway management.

End-tidal carbon dioxide monitoring during bag-valve ventilation: The use of a new portable device

BackgroundFor healthcare providers in the prehospital setting, bag-valve mask (BVM) ventilation could be as efficacious and safe as endotracheal intubation. To facilitate the evaluation of efficacious ventilation, capnographs have been further developed into small and convenient devices able to provide end- tidal carbon dioxide (ETCO2). The aim of this study was to investigate whether a new portable device (EMMA™) attached to a ventilation mask would provide ETCO2 values accurate enough to confirm proper BVM ventilation.MethodsA prospective observational trial was conducted in a single level-2 centre. Twenty-two patients under general anaesthesia were manually ventilated. ETCO2 was measured every five minutes with the study device and venous PCO2 (PvCO2) was simultaneously measured for comparison. Bland- Altman plots were used to compare ETCO2, and PvCO2.ResultsThe patients were all hemodynamically and respiratory stable during anaesthesia. End-tidal carbon dioxide values were corresponding to venous gases during BVM ventilation under optimal conditions. The bias, the mean of the differences between the two methods (device versus venous blood gases), for time points 1-4 ranges from -1.37 to -1.62.ConclusionThe portable device, EMMA™ is suitable for determining carbon dioxide in expired air (kPa) as compared to simultaneous samples of PvCO2. It could therefore, be a supportive tool to asses the BVM ventilation in the demanding prehospital and emergency setting.

Mass Critical Care: Pediatric Considerations in Extending and Rationing Care in Public Health Emergencies

This article applies developing concepts of mass critical care (MCC) to children. In public health emergencies (PHEs), MCC would improve population outcomes by providing lifesaving interventions while delaying less urgent care. If needs exceed resources despite MCC, then rationing would allocate interventions to those most likely to survive with care. Gaps between estimated needs and actual hospital resources are worse for children than adults. Clear identification of pediatric hospitals would facilitate distribution of children according to PHE needs, but all hospitals must prepare to treat some children. Keeping children with a family member and identifying unaccompanied children complicate PHE regional triage. Pediatric critical care experts would teach and supervise supplemental providers. Adapting nearly equivalent equipment compensates for shortages, but there is no substitute for age-appropriate resuscitation masks, IV/suction catheters, endotracheal/gastric/chest tubes. Limitations will be encountered using adult ventilators for infants. Temporary manual bag valve ventilation and development of shared ventilators may prolong survival until the arrival of ventilator stockpiles. To ration MCC to children most likely to survive, the Pediatric Index of Mortality 2 score meets the criteria for validated pediatric mortality predictions. Policymakers must define population outcome goals in regard to lives saved versus life-years saved.