Influence of Patient Weight on Prehospital Advanced Airway Procedure Success Rates.

OBJECTIVE: Previous investigations of the relationship between obesity and difficult airway management have provided mixed results. Almost universally, these studies were conducted in the hospital setting, and the influence of patient body weight on successful prehospital airway management remains unclear. Because patient weight could be one readily identifiable risk factor for problematic airway interventions, we sought to evaluate this relationship. METHODS: We conducted a retrospective analysis using the 2020 ESO Data Collaborative dataset. The inclusion criteria consisted of adult patients weighing >30kg with an attempted orotracheal intubation (OTI) and/or blind insertion airway device (BIAD) placement. Separate logistic regression models were developed to determine the influence of weight (dichotomized at 100 kg) on cumulative procedure success for OTI and BIAD, and linear regression models were used to identify trends for each across weight strata. RESULTS: A total of 45,344 patients met inclusionary criteria, among which 40,668(89.7%) suffered from a medical emergency, followed by 3,130(6.9%) with traumatic injuries, and 1,546(3.4%) attributable to a combined medical-trauma etiology. Cardiac arrest occurred either prior to EMS arrival or at some point during EMS care in 38,210(84.3%) patients. OTI was attempted in 18,153(40.0%) patients, while 21,597(47.6%) had a BIAD attempt and 5,594(12.3%) had both airway types attempted. The overall cumulative insertion success rates for OTI and BIAD were 79.5% and 92.7%, respectively. Altogether, 2,711(6.0%) had no advanced airway of any type successfully placed, which represents the overall failed advanced airway rate. After controlling for patient age, sex, minority status, and call type (medical vs. trauma), weight >100kg was associated with decreased likelihood of cumulative OTI success (OR = 0.64, p < 0.001), but higher likelihood of cumulative BIAD success (OR = 1.31, p < 0.001). Cumulative OTI success was associated with a negative 0.6% linear trend per 5 kg of body weight (p < 0.001) while cumulative BIAD success had a 0.2% positive trend (p < 0.001). CONCLUSION: This retrospective analysis of a national EMS database revealed that increasing patient weight was negatively associated with intubation success. A positive, but smaller, linear trend was observed for BIAD placement. Patient weight may be an easily identifiable predictor of difficult oral intubation and may be a consideration when selecting an airway management strategy.

Probability of Return of Spontaneous Circulation as a Function of Timing of Vasopressor Administration in Out-of-Hospital Cardiac Arrest.

INTRODUCTION: Vasopressors (epinephrine and vasopressin) are associated with return of spontaneous circulation (ROSC). Recent retrospective studies reported a greater likelihood of ROSC when vasopressors were administered within the first 10 minutes of arrest. However, it is unlikely that the relationship between ROSC and the timing of vasopressor administration is a binary function (i.e., ≤10 vs. >10 minutes). More likely, this relationship is a function of time measured on a continuum, with diminishing effectiveness even within the first 10 minutes of arrest, and potentially, some lingering benefit beyond 10 minutes. However, this relationship remains undefined. OBJECTIVE: To develop a model describing the likelihood of ROSC as a function of the call receipt to vasopressor interval (CRTVI) measured on a continuum. METHODS: We conducted a retrospective study of cardiac arrest using the North Carolina Prehospital Care Reporting System (PREMIS). Inclusionary criteria were all adult patients suffering a witnessed, nontraumatic arrest during January-June 2012. Chi-square and t-tests were used to analyze the relationships between ROSC and CRTVI; patient age, race, and gender; endotracheal intubation (ETI); automated external defibrillator (AED) use; presenting cardiac rhythm; and bystander cardiopulmonary resuscitation (CPR). A multivariate logistic regression model calculated the odds ratio (OR) of ROSC as a function of CRTVI while controlling for potential confounding variables. RESULTS: Of the 1,122 patients meeting inclusion criteria, 542 (48.3%) experienced ROSC. ROSC was less likely with increasing CRTVI (OR = 0.96, p < 0.01). Compared to patients with shockable rhythms, patients with asystole (OR = 0.42, p < 0.01) and pulseless electrical activity (OR = 0.52, p < 0.01) were less likely to achieve ROSC. Males (OR = 0.64, p = 0.02) and patients receiving bystander CPR (OR = 0.42, p < 0.01) were less likely to attain ROSC, although emergency medical services response times were significantly longer among patients receiving bystander CPR. Race, age, ETI, and AED were not predictors of ROSC. CONCLUSIONS: We found that time to vasopressor administration is significantly associated with ROSC, and the odds of ROSC declines by 4% for every 1-minute delay between call receipt and vasopressor administration. These results support the notion of a time-dependent function of vasopressor effectiveness across the entire range of administration delays rather than just the first 10 minutes. Large, prospective studies are needed to determine the relationship between the timing of vasopressor administration and long-term outcomes.

Interevaluator reliability of a mock paramedic practical examination.

INTRODUCTION: Prior to graduation, paramedic students must be assessed for terminal competency and preparedness for national credentialing examinations. Although the procedures for determining competency vary, many academic programs use a practical and/or oral examination, often scored using skill sheets, for evaluating psychomotor skills. However, even with validated testing instruments, the interevaluator reliability of this process is unknown. Objective. We sought to estimate the interevaluator reliability of a subset of paramedic skills as commonly applied in terminal competency testing. METHODS: A mock examinee was videotaped performing staged examinations mimicking adult ventilatory management, oral board, and static and dynamic cardiac stations during which the examinee committed a series of prespecified errors. The videotaped performances were then evaluated by a group of qualified evaluators using standardized skill sheets. Interevaluator variability was measured by standard deviation and range, and reliability was evaluated using Krippendorff's alpha. Correlation between scores and evaluator demographics was assessed by Pearson correlation. RESULTS: Total scores and critical errors varied considerably across all evaluators and stations. The mean (± standard deviation) scores were 24.77 (±2.37) out of a possible 27 points for the adult ventilatory management station, 11.69 (±2.71) out of a possible 15 points for the oral board station, 7.79 (±3.05) out of a possible 12 points for the static cardiology station, and 22.08 (±1.46) out of a possible 24 points for the dynamic cardiology station. Scores ranged from 18 to 27 for adult ventilatory management, 7 to 15 for the oral board, 2 to 12 for static cardiology, and 19 to 24 for dynamic cardiology. Krippendorff's alpha coefficients were 0.30 for adult ventilatory management, 0.01 for the oral board, 0.10 for static cardiology, and 0.48 for dynamic cardiology. Critical criteria errors were assigned by 10 (38.5%) evaluators for adult ventilatory management, five (19.2%) for the oral board, and nine (34.6%) for dynamic cardiology. Total scores were not correlated with evaluator demographics. CONCLUSIONS: There was high variability and low reliability among qualified evaluators using skill sheets as a scoring tool in the evaluation of a mock terminal competency assessment. Further research is needed to determine the true overall interevaluator reliability of this commonly used approach, as well as the ideal number, training, and characteristics of prospective evaluators.