Novel Negative Pressure Procedural Tent Reduces Aerosolized Particles in a Simulated Prehospital Setting.

BACKGROUND/OBJECTIVE: The coronavirus disease 2019 (COVID-19) pandemic has challenged the ability of Emergency Medical Services (EMS) providers to maintain personal safety during the treatment and transport of patients potentially infected. Increased rates of COVID-19 infection in EMS providers after patient care exposure, and notably after performing aerosol-generating procedures (AGPs), have been reported. With an already strained workforce seeing rising call volumes and increased risk for AGP-requiring patient presentations, development of novel devices for the protection of EMS providers is of great importance.Based on the concept of a negative pressure room, the AerosolVE BioDome is designed to encapsulate the patient and contain aerosolized infectious particles produced during AGPs, making the cabin of an EMS vehicle safer for providers. The objective of this study was to determine the efficacy and safety of the tent in mitigating simulated infectious particle spread in varied EMS transport platforms during AGP utilization. METHODS: Fifteen healthy volunteers were enrolled and distributed amongst three EMS vehicles: a ground ambulance, an aeromedical-configured helicopter, and an aeromedical-configured jet. Sodium chloride particles were used to simulate infectious particles and particle counts were obtained in numerous locations close to the tent and around the patient compartment. Counts near the tent were compared to ambient air with and without use of AGPs (non-rebreather mask, continuous positive airway pressure [CPAP] mask, and high-flow nasal cannula [HFNC]). RESULTS: For all transport platforms, with the tent fan off, the particle generator alone, and with all AGPs produced particle counts inside the tent significantly higher than ambient particle counts (P <.0001). With the tent fan powered on, particle counts near the tent, where EMS providers are expected to be located, showed no significant elevation compared to baseline ambient particle counts during the use of the particle generator alone or with use of any of the AGPs across all transport platforms. CONCLUSION: Development of devices to improve safety for EMS providers to allow for use of all available therapies to treat patients while reducing risk of communicable respiratory disease transmission is of paramount importance. The AerosolVE BioDome demonstrated efficacy in creating a negative pressure environment and workspace around the patient and provided significant filtration of simulated respiratory droplets, thus making the confined space of transport vehicles potentially safer for EMS personnel.

Novel Negative Pressure Helmet Reduces Aerosolized Particles in a Simulated Prehospital Setting.

BACKGROUND/OBJECTIVE: The coronavirus disease 2019 (COVID-19) pandemic has created challenges in maintaining the safety of prehospital providers caring for patients. Reports have shown increased rates of Emergency Medical Services (EMS) provider infection with COVID-19 after patient care exposure, especially while utilizing aerosol-generating procedures (AGPs). Given the increased risk and rising call volumes for AGP-necessitating complaints, development of novel devices for the protection of EMS clinicians is of great importance.Drawn from the concept of the powered air purifying respirator (PAPR), the AerosolVE helmet creates a personal negative pressure space to contain aerosolized infectious particles produced by patients, making the cabin of an EMS vehicle safer for providers. The helmet was developed initially for use in hospitals and could be of significant use in the prehospital setting. The objective of this study was to determine the efficacy and safety of the helmet in mitigating simulated infectious particle spread in varied EMS transport platforms during AGP utilization. METHODS: Fifteen healthy volunteers were enrolled and distributed amongst three EMS vehicles: a ground ambulance, a medical helicopter, and a medical jet. Sodium chloride particles were used to simulate infectious particles, and particle counts were obtained in numerous locations close to the helmet and around the patient compartment. Counts near the helmet were compared to ambient air with and without use of AGPs (non-rebreather mask [NRB], continuous positive airway pressure mask [CPAP], and high-flow nasal cannula [HFNC]). RESULTS: Without the helmet fan on, the particle generator alone and with all AGPs produced particle counts inside the helmet significantly higher than ambient particle counts. With the fan on, there was no significant difference in particle counts around the helmet compared to baseline ambient particle counts. Particle counts at the filter exit averaged less than one despite markedly higher particle counts inside the helmet. CONCLUSION: Given the risk to EMS providers by communicable respiratory diseases, development of devices to improve safety while still enabling use of respiratory therapies is of paramount importance. The AerosolVE helmet demonstrated efficacy in creating a negative pressure environment and provided significant filtration of simulated respiratory droplets, thus making the confined space of transport vehicles potentially safer for EMS personnel.

Defining a Theory-Driven Ultrasound Curriculum for Prehospital Providers.

Advances in point-of-care ultrasound technology have allowed for the extension of emergency medicine ultrasound beyond the walls of the emergency department. Emergency medical system providers may benefit from the use of ultrasound. It has previously been shown that with a brief introductory course, novices can obtain and correctly interpret focused ultrasound examinations. The purpose of this study was to design a theory-driven point-of-care ultrasound curriculum to assess and develop ultrasound skill in prehospital providers. The resultant curriculum outlined in this paper encompasses a large array of skills that may be useful for different prehospital services to use to develop curriculum for their own needs.

Inhaled nitric oxide to improve oxygenation for safe critical care transport of adults with severe hypoxemia.

BACKGROUND: Inhaled nitric oxide (iNO) is a rescue treatment for severe hypoxemia in the intensive care unit setting. OBJECTIVE: To evaluate the effectiveness and safety of iNO in adult patients with severe hypoxemia before and during transport to a tertiary care center. METHODS: Prospective data were examined in a retrospective cohort study. Patients with severe hypoxemia and cardiopulmonary failure (n=139) at referring hospitals in whom conventional therapy was unsuccessful were treated with iNO in the intensive care units in anticipation of transfer to a tertiary center. Treatment wih iNO was initiated by the critical care transport team in 114 patients and continued in 25 patients. Arterial blood gas analysis was done before and after iNO treatment. RESULTS: Patients treated with iNO had significant improvement in oxygenation: mean (SD) for PaO2 increased from 60.7 (20.2) to 72.3 (40.6) mm Hg (P=.008), and mean (SD) for ratio of PaO2 to fraction of inspired oxygen (P:F) increased from 62.4 (26.1) to 73.1 (42.6) (P= .03). Use of iNO was continued through transport in 102 patients, all of whom were transported without complication. The P:F continued to improve, with a mean (SD) of 109.7 (73.8) from 6 to 8 hours after arrival at the tertiary center (P< .001 relative to values both before and after treatment). Among patients treated with iNO, 60.2% survived to discharge. In 35 nonresponders, iNO was discontinued, and 15 patients could not be transferred owing to life-threatening hypoxemia; 2 were later transferred on extracorporeal membrane oxygenation. Of 18 patients transported without iNO, 9 (50%) survived. CONCLUSIONS: Use of iNO significantly improves oxygenation of patients with severe hypoxemia and allows safe transfer to a tertiary care center.

Airway management success and hypoxemia rates in air and ground critical care transport: a prospective multicenter study.

OBJECTIVE: To assess critical care transport (CCT) crews' endotracheal intubation (ETI) attempts, success rates, and peri-ETI oxygenation. METHODS: Participants were adult and pediatric patients undergoing attempted advanced airway management during the period from July 2007 to December 2008 by crews from 11 CCT programs varying in geography, crew configuration, and casemix; all crews had access to neuromuscular-blocking agents. Data collected included airway management variables defined per national consensus criteria. Descriptive analysis focused on ETI success rates (reported with exact binomial 95% confidence intervals [CIs]) and occurrence of new hypoxemia (oxygen saturation [SpO(2)] dropping below 90% during or after ETI); to assess categorical variables, Fisher's exact test, Pearson chi(2), and logistic regression were employed to explore associations between predictor variables and ETI failure or new hypoxemia. For all tests, p < 0.05 defined significance. RESULTS: There were 603 total attempts at airway management, with successful oral or nasal ETI in 582 cases, or 96.5% (95% CI 94.7-97.8%). In 182 cases (30.2%, 95% CI 26.5-34.0%), there were failed ETI attempts prior to CCT crew arrival; CCT crew ETI success on these patients (96.2%, 95% CI 92.2-98.4%) was just as high as in the patients in whom there was no pre-CCT ETI attempt (p = 0.81). New hypoxemia occurred in only six cases (1.6% of the 365 cases with ongoing SpO(2) monitoring; 95% CI 0.6-3.5%); the only predictor of new hypoxemia was pre-ETI hypotension (p < 0.001). A requirement for multiple ETI attempts by CCT crews was not associated with new hypoxemia (Fisher's exact p = 0.13). CONCLUSIONS: CCT crews' ETI success rates were very high, and even when ETI required multiple attempts, airway management was rarely associated with SpO(2) derangement. CCT crews' ETI success rates were equally high in the subset of patients in whom ground emergency medical services (EMS) ETI failed prior to arrival of transport crews.

Critical care transport of patients who have acute neurological emergencies.

This article reviews the special questions and issues in critical care transport related specifically to the care of patients who have neurologic emergencies. It first considers potential indications for transport and reviews attempts to create a hierarchical stroke center system akin to that developed for trauma care. It then discusses therapeutic concerns relating to the transport environment and the use of specific interventions, including the effects of end-tidal CO(2) monitoring on intracranial pressure, patient outcomes after traumatic brain injury, and opportunities to initiate therapeutic hypothermia in comatose survivors of cardiac arrest during transport. Finally, the cost of critical care transport of patients who have neurologic emergencies is considered.

Quality of emergency care on the night shift.

OBJECTIVES: To determine whether performance decrements at night actually translate into worsened measures of quality of patient care in the emergency department (ED). Emergency physicians and healthcare workers are sleepier and less cognitively proficient at night than during the day. Despite a lack of data, medical errors have been attributed to these deficits, and pharmacologic solutions recently have been suggested. METHODS: The authors studied 36 months of emergency care and measured quality indicators, including early mortality (deaths occurring after arrival in the ED or within 48 hours of hospital admission), frequency of return after ED discharge, time to thrombolysis in acute myocardial infarction (AMI), frequency of aspirin use in AMI, and performance of endotracheal intubation. Comparisons were by time of day in eight-hour epochs. RESULTS: There were 345,000 patient encounters in the study period. The distribution in time was determined for 25,079 sampled ED visits, 3,666 admissions, and 507 early deaths. Estimated early mortality was 0.5% (95% CI = 0.0 to 1.0%) greater at night compared with during the day. There was no effect of time of day on 1,828 returns with admission after ED discharge. In 257 patients who received thrombolytics for AMI, mean time-to-treatment and frequency of aspirin use were not worse at night. In 443 emergent endotracheal intubations, there was no difference at night in the duration or number of attempts required, or in protocol adherence. CONCLUSIONS: Quality indicators used in this study do not demonstrate marked deficits in patient care occurring at night. A very small, but measurable, increase in early mortality was identified. Improved measures to counter circadian disruption warrant study but may result in minimal improvements in patient care.

Cost-effectiveness of helicopter transport of stroke patients for thrombolysis.

OBJECTIVES: Treatment with intravenous (IV) or intra-arterial (IA) thrombolysis in patients with acute ischemic stroke demands careful patient selection and specialized institutional capabilities. Physicians at hospitals without these resources may prefer patient transfer for acute treatment. Helicopter transport for these patients has been described but without analysis of the effects of its additional cost. The authors examined the cost-effectiveness of helicopter transport for patients with acute stroke. METHODS: Costs per additional good outcome and per quality-adjusted life-year (QALY) were calculated using a computer model. Input variables included flight, thrombolytic agent, and angiography costs; annual cost per patient for long-term care of symptomatic stroke; percentage of transported patients treated; percentage of patients receiving IV versus IA therapy; discount rate; absolute probability of good outcome; annual mortality with and without treatment; and quality-of-life modifier. Sensitivity analysis was performed. RESULTS: Helicopter transport of acute stroke patients to tertiary care centers for thrombolytic therapy costs $35,000 per additional good outcome and $3,700 per QALY for the reference case. Cost-effectiveness was sensitive to the effectiveness of thrombolysis but minimally sensitive to most other input values. Cost per QALY ranged from $0 to $50,000, as the absolute increase in good outcomes (minimal or no deficit) ranged from 20% to 5%. Cost-effectiveness was not sensitive to ranges of helicopter flight costs or the proportion of flown patients undergoing treatment. CONCLUSIONS: This model indicates helicopter transfer of patients with suspected acute ischemic stroke for potential thrombolysis is cost-effective for a wide range of system variables.

Long-term air medical services system performance using APACHE-II and mortality benchmarking.

OBJECTIVE: Air medical transport programs have been in existence for two decades. During this time, no outcome measures have been developed for these services. The authors examined severity scoring and mortality data from their air medical service to characterize its performance and to identify trends in acuity and mortality over a 15-year period. METHODS: APACHE-II scores derived at the time of transport and hospital mortality data have been concurrently recorded in the flight database for adult transports since 1986. The authors analyzed these data and examined the correlation between APACHE-II score at the time of transport and hospital mortality for the 15-year period 1986-2001. RESULTS: 13,808 adult transports were identified. APACHE data were available for 8,204 patients (59%) and mortality for 10,845 (79%), respectively. The number of transports increased from 935 to 1,231 per year. Mean APACHE-II for all patients was 11.6 +/- 8.4. Overall mortality was 22%. Both patient acuity and mortality were trending upward over time. The correlation between APACHE-II and mortality was close and linear (mortality = 0.018 x APACHE-II -0.0243, R2 = 0.97). CONCLUSIONS: Both severity of illness and mortality of air-transported patients appear to be increasing slowly over time in response to changes in the health care system. The strong correlation between APACHE-II performed at the time of transport and mortality validates this technique for benchmarking. The slope of this correlation is an outcome-based characteristic of system performance that may allow monitoring of a system over time and comparisons between systems.