Jennifer C. Poste

Hospital Bed Surge Capacity in the Event of a Mass-Casualty Incident

INTRODUCTION Traditional strategies to determine hospital bed surge capacity have relied on cross-sectional hospital census data, which underestimate the true surge capacity in the event of a mass-casualty incident. OBJECTIVE To determine hospital bed surge capacity for the County more accurately using physician and nurse manager assessments for the disposition of all in-patients at multiple facilities. METHODS Overnight- and day-shift nurse managers from each in-patient unit at four different hospitals were approached to make assessments for each patient as to their predicted disposition at 2, 24, and 72 hours post-event in the case of a mass-casualty incident, including transfer to a hypothetical, onsite nursing facility. Physicians at the two academic institutions also were approached for comparison. Age, gender, and admission diagnosis also were recorded for each patient. RESULTS A total of 1,741 assessments of 788 patients by 82 nurse managers and 25 physicians from the four institutions were included. Nurse managers assessed approximately one-third of all patients as dischargeable at 24 hours and approximately one-half at 72 hours; one-quarter of the patients were assessed as being transferable to a hypothetical, on-site nursing facility at both time points. Physicians were more likely than were nurse managers to send patients to such a facility or discharge them, but less likely to transfer patients out of the intensive care unit (ICU). Inter-facility variability was explained by differences in the distribution of patient diagnoses. CONCLUSIONS A large proportion of in-patients can be discharged within 24 and 72 hours in the event of a mass-casualty incident (MCI). Additional beds can be made available if an on-site nursing facility is made available. Both physicians and nurse managers should be included on the team that makes patient dispositions in the event of a MCI.

The Safety andEfficacy of Prehospital Needle andTube Thoracostomy by Aeromedical Personnel

Background.Aeromedical crews routinely use needle thoracostomy (NT) andtube thoracostomy (TT) to treat major trauma victims (MTVs) with potential tension pneumothorax; however, the efficacy of prehospital NT andTT is unclear.Objectives.To explore the efficacy of aeromedical NT andTT in MTVs.Methods.A retrospective chart review was performed using prehospital medical records andthe county trauma registry over a seven-year period. All MTVs undergoing placement of NT or TT by aeromedical personnel were included; patients with incomplete data were excluded. Descriptive statistics were used to report the incidence of air release, clinical improvement (improved breath sounds or compliance if intubated, decreased dyspnea if nonintubated), andvital signs improvements (systolic blood pressure [SBP] increase to ≥90 mm Hg or increase by 5 mm Hg if < 90 mm Hg; heart rate improvement to 60–100 beats/min, increase by 10 beats/min if < 60 BPM, or decrease by 10 beats/min if > 100 beats/min; oxygen saturation increase if < 95%) for both NT andTT as documented in prehospital medical records. Survival andimprovement in SBP based on trauma registry data were recorded for patients stratified by initial SBP.Results.A total of 136 procedures (89 NTs and47 TTs) in 81 patients were identified using prehospital medical records over a four-year period. Response rates to NT (60% overall, 32% vital signs) andTT (75% overall, 60% vital signs) were high. Vital signs improvements were observed more often in patients with a pulse andin nonintubated patients. A total of 168 patients were identified in the trauma registry over the seven-year study period. Normalization of SBP was observed in two-thirds of patients with a field SBP ≤ 90 mm Hg andone-third of patients in whom field SBP could not be obtained. A small but significant proportion of patients undergoing prehospital NT andTT, including some with prehospital hypotension andhigh injury severity, survived to hospital discharge. The incidence of complications was low.Conclusions.Aeromedical crews appear to appropriately select MTVs to undergo field NT or TT. A low incidence of complications anda small but significant group of unexpected survivors support continued use of this procedure by aeromedical personnel.Key words:aeromedical crews; trauma; needle thoracostomy; tube thoracostomy; survival; pneumothorax; efficacy.

Ventilation patterns in patients with severe traumatic brain injury following paramedic rapid sequence intubation

Introduction: Inadvertent hyperventilation has been documented during aeromedical transports but has not been studied following paramedic rapid sequence intubation (RSI). The San Diego Paramedic RSI Trial was designed to study the impact of paramedic RSI on outcome in patients with severe head injury. This analysis explores ventilation patterns in a cohort of trial patients undergoing end-tidal CO2 (ETCO2) monitoring.Methods: Adult patients with severe head injury (Glasgow Coma Score: 3–8) unable to be intubated without RSI were prospectively enrolled in the trial. Midazolam and succinylcholine were used for RSI; rocuronium was administered following tube confirmation. Standardized ventilation protocols were used by most paramedics; however, one agency instituted ETCO2 monitoring during the second trial year, with paramedics instructed to target ETCO2 values of 30 to 35 mmHg. The incidence and duration of inadvertent hyperventilation (ETCO2:<30 mmHg) and severe hyperventilation (ETCO2:<25 mmHg) were explored for patients undergoing ETCO2 monitoring. The initial, final, minimum, and maximum values for ETCO2 and the maximum and minimum ventilatory rate values were also calculated using descriptive statistics (95% confidence interval). The pattern of ETCO2 values over time and distribution of recorded ventilatory rate values were explored graphically.Results: A total of 76 trial patients had adequate ETCO2 data for this analysis. The mean values for initial, final, maximum, and minimum ETCO2 were 40.8 (range: 37.5–44.2), 28.4 (range: 25.4–31.4), 45.1 (range: 41.4–48.8), and 23.5 mmHg (range: 21.4–25.5), respectively. The mean maximum and minimum ventilatory rate values were 36.0/minute (range: 33.5–38.5) and 12.8/minute (range: 11.9–13.7), respectively. ETCO2 values less than 30 and 25 mmHg were documented in 79% and 59% of patients, respectively, with mean durations of 485 (range: 378–592) and 390 seconds (range: 285–494).Conclusion: Inadvertent hyperventilation is common following paramedic RSI, despite ETCO2 monitoring and target parameters.

Predictors of Intubation Success andTherapeutic Value of Paramedic Airway Management in a Large, Urban EMS System

Background. Endotracheal intubation (ETI) is commonly used by paramedics for definitive airway management. The predictors of success andtherapeutic value with regard to oxygenation are not well studied. Objectives. 1) To explore the relationship between intubation success andperfusion status, Glasgow Coma Scale (GCS) score, andend-tidal carbon dioxide (EtCO2); 2) to describe the incidence of unrecognized esophageal intubations with use of continuous capnometry; and3) to document the incremental benefit of invasive versus noninvasive airway management techniques in correcting hypoxemia. Methods. This was a prospective, observational study conducted in a large urban emergency medical services system. Paramedics completed a telephone debriefing interview with quality assurance personnel following delivery of all patients in whom invasive airway management had been attempted. Continuous capnometry was used for confirmation of tube position in all patients. Descriptive statistics were used to document airway management performance, including first-attempt ETI success, overall ETI success, andCombitube insertion (CTI) success. In addition, the incidence of unrecognized esophageal intubation was recorded. The relationship between intubation success andperfusion status, GCS score, andinitial EtCO2 value was explored using logistic regression. Finally, recorded SpO2 values andthe incidence of hypoxemia (SpO2 < 90%) at baseline, following noninvasive airway maneuvers, andafter invasive airway management were compared for perfusing patients. Results. A total of 703 patients were enrolled over 12 months. First-attempt ETI success was 61%, andoverall ETI success was 81%; invasive airway management (ETI or CTI) was unsuccessful in 11% of patients. A single unrecognized esophageal intubation was observed (0.1%). A clear relationship between airway management success andperfusion status, GCS score, andinitial EtCO2 value was observed. Only EtCO2 demonstrated an independent association with ETI success after adjusting for the other variables. Significant improvements in mean SpO2 andthe incidence of hypoxemia over baseline were observed with both noninvasive andinvasive airway management techniques in 168 perfusing patients. Conclusions. A relationship between intubation success andperfusion status, GCS score, andinitial EtCO2 value was observed. Capnometry was effective in eliminating unrecognized esophageal intubations. Both noninvasive andinvasive airway management strategies were effective in increasing SpO2 values anddecreasing the incidence of hypoxemia, with additional benefit observed with invasive airway maneuvers in some patients.