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.

BACKGROUND: The 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. METHODS: MBV 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. RESULTS: Between 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). CONCLUSIONS: Compared 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.

Effect of Bag-Mask Ventilation vs Endotracheal Intubation During Cardiopulmonary Resuscitation on Neurological Outcome After Out-of-Hospital Cardiorespiratory Arrest: A Randomized Clinical Trial.

Importance: Bag-mask ventilation (BMV) is a less complex technique than endotracheal intubation (ETI) for airway management during the advanced cardiac life support phase of cardiopulmonary resuscitation of patients with out-of-hospital cardiorespiratory arrest. It has been reported as superior in terms of survival. Objectives: To assess noninferiority of BMV vs ETI for advanced airway management with regard to survival with favorable neurological function at day 28. Design, Settings, and Participants: Multicenter randomized clinical trial comparing BMV with ETI in 2043 patients with out-of-hospital cardiorespiratory arrest in France and Belgium. Enrollment occurred from March 9, 2015, to January 2, 2017, and follow-up ended January 26, 2017. Intervention: Participants were randomized to initial airway management with BMV (n = 1020) or ETI (n = 1023). Main Outcomes and Measures: The primary outcome was favorable neurological outcome at 28 days defined as cerebral performance category 1 or 2. A noninferiority margin of 1% was chosen. Secondary end points included rate of survival to hospital admission, rate of survival at day 28, rate of return of spontaneous circulation, and ETI and BMV difficulty or failure. Results: Among 2043 patients who were randomized (mean age, 64.7 years; 665 women [32%]), 2040 (99.8%) completed the trial. In the intention-to-treat population, favorable functional survival at day 28 was 44 of 1018 patients (4.3%) in the BMV group and 43 of 1022 patients (4.2%) in the ETI group (difference, 0.11% [1-sided 97.5% CI, -1.64% to infinity]; P for noninferiority = .11). Survival to hospital admission (294/1018 [28.9%] in the BMV group vs 333/1022 [32.6%] in the ETI group; difference, -3.7% [95% CI, -7.7% to 0.3%]) and global survival at day 28 (55/1018 [5.4%] in the BMV group vs 54/1022 [5.3%] in the ETI group; difference, 0.1% [95% CI, -1.8% to 2.1%]) were not significantly different. Complications included difficult airway management (186/1027 [18.1%] in the BMV group vs 134/996 [13.4%] in the ETI group; difference, 4.7% [95% CI, 1.5% to 7.9%]; P = .004), failure (69/1028 [6.7%] in the BMV group vs 21/996 [2.1%] in the ETI group; difference, 4.6% [95% CI, 2.8% to 6.4%]; P < .001), and regurgitation of gastric content (156/1027 [15.2%] in the BMV group vs 75/999 [7.5%] in the ETI group; difference, 7.7% [95% CI, 4.9% to 10.4%]; P < .001). Conclusions and Relevance: Among patients with out-of-hospital cardiorespiratory arrest, the use of BMV compared with ETI failed to demonstrate noninferiority or inferiority for survival with favorable 28-day neurological function, an inconclusive result. A determination of equivalence or superiority between these techniques requires further research. Trial Registration: clinicaltrials.gov Identifier: NCT02327026.

Comparison of clinical-based and ECG-based triage of acute chest pain in the Emergency Department.

In the Emergency Department, chest pain triage systems are based on either clinical features or ECG recording. In this prospective, single-center, observational study, we aimed to compare the diagnostic performance of these triage systems in distinguishing acute coronary syndromes (ACS) from diseases of mild severity. Patients were sorted into the triage systems based on collected data at admission and on a systematic 12-lead ECG performed at triage. The final diagnosis was determined after a 30-day follow-up. For ACS, we determined a high-acuity triage score (Level 1 or 2) as being adequate, and for mild severity diseases a low-acuity triage score (Level 3, 4 or 5) as being adequate. The diagnostic performance of all studied systems was moderate (AUC from 0.644 to 0.694), with no statistically significant difference found between them. However, characteristics of the systems differed because the clinical-based systems had a higher sensitivity (87-91%) but lower specificity (32-39%) compared with the ECG-based system (sensitivity 62% and specificity 64%). A higher sensitivity limits the risk of a patient with acute coronary syndrome staying unsafely in the waiting room, while a higher specificity prevents overcrowding. ECG at triage also ensures that no STEMIs or high-risk NSTEMIs are missed. Based on these findings, each Emergency Depatment could more accurately select the triage system that fits their local particularities.

Capnography as a diagnostic tool for pulmonary embolism: a meta-analysis.

STUDY OBJECTIVE: Multiple studies have evaluated capnography for the diagnosis of pulmonary embolism; accordingly, we conduct a meta-analysis of these trials. METHODS: We performed a systematic search from 1990 to 2011, using MEDLINE, EMBASE, and the Cochrane Library, including studies evaluating capnography as a diagnostic tool alone or in conjunction with other tests. After study quality evaluation, we calculated the pooled sensitivity, specificity, likelihood ratios, and diagnostic odds ratios. RESULTS: We included 14 trials with 2,291 total subjects, with a 20% overall prevalence of pulmonary embolism. The pooled diagnostic accuracy for capnography was sensitivity 0.80 (95% confidence interval [CI] 0.76 to 0.83), specificity 0.49 (95% CI 0.47 to 0.51), negative likelihood ratio 0.32 (95% CI 0.23 to 0.45), positive likelihood ratio 2.43 (95% CI 1.70 to 3.46), and diagnostic odds ratio 10.4 (95% CI 6.33 to 17.1). The area under the summary receiver operating characteristic curve was 0.84. To reach pulmonary embolism posttest probabilities less than 1%, 2%, or 5%, pulmonary embolism prevalence or pretest probability had to be less than 3%, 5%, or 10% respectively. Because of interstudy differences in dead space measurements methodologies, the best cutoff in alveolar dead space or end tidal CO2 conferring the best negative likelihood ratio could not be evaluated. CONCLUSION: Pooled data suggest a potential diagnostic role for capnography when the pulmonary embolism pretest probability is 10% or less, perhaps after a positive D-dimer test result.

Lactic acidosis following intentional overdose by inhalation of salmeterol and fluticasone.

Salmeterol, a long-acting ß2-adrenergic receptor agonist used for the treatment of asthma and chronic obstructive pulmonary disease, has an adverse effects profile that is similar to that of salbutamol and other ß2-agonists. We report a sympathomimetic syndrome with metabolic acidosis and hyperlactatemia after intentional inhalation of salmeterol in a suicide attempt. A 16-year-old female patient was admitted to the emergency department approximately 2 hours after having inhaled 60 puffs of a combination of salmeterol xinafoate 25 µg and fluticasone propionate 50 µg. She presented in an anxious state with complaints of palpitations and chest pain. The electrocardiogram demonstrated sinus tachycardia and ST-segment depression in the inferior and anterolateral leads. Laboratory findings showed hypokalemia, hypophosphatemia, and lactic acidosis. Cardiac troponin I and creatine kinase MB remained within the normal range. Treatment was supportive and included intravenous fluids and cautious potassium supplementation. The next day, electrocardiographic and laboratory findings returned to normal. We hypothesize that stimulation of ß2-adrenergic receptors by inhalation of salmeterol caused this patient's lactic acidosis. This observation is consistent with the hypothesis that the hyperlactatemia observed during asthma attacks is due in part to the administration of high doses of ß2-agonists. Salmeterol overdose by inhalation appears to be sufficient to cause lactic acidosis.