Annette O. Arthur

Helicopter EMS: Research Endpoints and Potential Benefits.

Patients, EMS systems, and healthcare regions benefit from Helicopter EMS (HEMS) utilization. This article discusses these benefits in terms of specific endpoints utilized in research projects. The endpoint of interest, be it primary, secondary, or surrogate, is important to understand in the deployment of HEMS resources or in planning further HEMS outcomes research. The most important outcomes are those which show potential benefits to the patients, such as functional survival, pain relief, and earlier ALS care. Case reports are also important “outcomes” publications. The benefits of HEMS in the rural setting is the ability to provide timely access to Level I or Level II trauma centers and in nontrauma, interfacility transport of cardiac, stroke, and even sepsis patients. Many HEMS crews have pharmacologic and procedural capabilities that bring a different level of care to a trauma scene or small referring hospital, especially in the rural setting. Regional healthcare and EMS systems benefit from HEMS by their capability to extend the advanced level of care throughout a region, provide a “backup” for areas with limited ALS coverage, minimize transport times, make available direct transport to specialized centers, and offer flexibility of transport in overloaded hospital systems.

Hemodynamic consequences of ketamine vs etomidate for endotracheal intubation in the air medical setting

OBJECTIVE Recent drug shortages have required the occasional replacement of etomidate for endotracheal intubation (ETI) by helicopter emergency medical services (HEMS), with ketamine. The purpose of this study was to assess whether there was an association between ketamine vs etomidate use as the main ETI drug, with hemodynamic or clinical (airway) end points. METHODS This retrospective study used data entered into medical records at the time of HEMS transport. Subjects, 50 ketamine and 50 etomidate, were accrued from 3 US HEMS programs. The study period was from August 2011 through May 2012. Data collection included demographics, diagnostic category, ETI drugs use, ETI success, and complications. Hemodynamic parameters were assessed for up to 2 sets of vital signs before airway management and up to 5 sets of post-ETI vital signs. Significance was defined at the P < .05 level. RESULTS Patients on ketamine and etomidate were similar (P > .05) with respect to age, sex, scene/interfacility mission type, trauma vs nontrauma, neuromuscular blocking agent use, and rates of coadministration of fentanyl or midazolam. All patients had successful airway placement. Peri-ETI hypoxemia was seen in 10% of etomidate and 16% of ketamine cases (P = .55). The pre-ETI and post-ETI were similar between the ketamine and etomidate groups with respect to systolic blood pressure and heart rate at every vital signs assessment after ETI. CONCLUSION Initial assessment of ETI success and complication rates, as well as peri-ETI hemodynamic changes, suggests no concerning complications associated with large-scale replacement of etomidate with ketamine as the major airway management drug for HEMS.

Helicopter Transport Effectiveness of Patients for Primary Percutaneous Coronary Intervention

BACKGROUND For patients with ST-elevated myocardial infarction (STEMI), time to primary percutaneous coronary intervention (PCI) is an important factor in saving myocardium. Helicopter emergency medical service (HEMS) has become a vital component in regionalized cardiac care. The objective of this study is to assess the logistics of HEMS and ground EMS for interfacility transport of STEMI patients for primary PCI and to determine the effectiveness of HEMS transports in terms of the number of lives saved per 100 flights. METHODS This is a retrospective database and records review of interfacility transports of STEMI patients for primary PCI to a single medical center. The study period consisted of 18 months (January 2010 through June 2011). RESULTS Ninety-seven of 120 patients met the criteria for review. Of these, 66% were transported by HEMS. The pretransport patient handling times were similar for the HEMS and ground EMS groups. Door-to-PCI in < 120 minutes was achieved in 35.5% (11 of 31) of ground EMS and 24.2% (16 of 66) of HEMS. Patients transported by ground EMS were more likely to get to PCI in < 90 minutes (9.7%, 3 of 31). HEMS patients traveled significantly farther distances, 51 miles (IQR 43-68) than ground EMS, 37 miles (IQR 18-51). This equates to a 38% longer distance for patients transported by HEMS. An estimate of the driving time for HEMS-transported patients suggests HEMS transports saved a median of 41 minutes (IQR 33-48). The proportion of HEMS flights saving more than 30 minutes was 78.8% (95% CI 67.0-87.9%). CONCLUSION The results did not show a time savings for HEMS- versus ground EMS-transported patients. When estimates of time spent for ground EMS of actual HEMS transported patients are analyzed, HEMS provides a median savings of 41 minutes, with a savings of at least 30 minutes in 78.8% of the HEMS patients. Based on estimates used in this study, conservative calculations arrived at a time-based mortality effectiveness of HEMS of about 1.2 lives saved per 100 flights.

Pneumothorax Volume Expansion in Helicopter Emergency Medical Services Transport

OBJECTIVE In accordance with Boyles law (as barometric pressure decreases, gas volume increases), thoracostomy is often recommended for patients with pneumothoraces before helicopter EMS (HEMS) transport. We sought to characterize altitude-related volume changes in a pneumothorax model, aiming to improve clinical decisions for preflight thoracostomy in HEMS patients. METHODS This prospective study used 3 devices to measure air expansion at HEMS altitudes. The main device was an artificial pneumothorax model that mimicked a human pulmonary system with a 40 mL pneumothorax. In addition, volume changes were calculated in 2 spherical balloons (6 L and 25 L) by measuring equatorial circumferences. Measurements were recorded at 500-foot altitude increments from 1000 to 5000 feet above ground level. RESULTS The 3 models exhibited volume increases of 12.7%-16.2% at 5000 feet compared to ground level. Univariate linear regression yielded similar increases, 1.27%-1.52%, in volume per 500-foot altitude increase for all 3 models. Bivariate indexed linear regression identified no association between volume increase and assessment model (P values .19 and .29). Locally weighted scatterplot smoothing (lowess) plots indicated linearity of the altitude-volume relationship. CONCLUSION This study demonstrated predictable pneumothorax volume changes at typical HEMS altitudes. Increased understanding of altitude-related volume changes will aid decision making before transport.

Helicopter Emergency Medical Services Crew Administration of Antibiotics for Open Fractures

This study had 3 major aims: (1) to ascertain the degree to which helicopter emergency medical services (HEMS) administration of antibiotics (Abx) can streamline the time to Abx in open fracture patients, (2) to determine whether any clinical outcome improvements were associated with HEMS Abx therapy, and (3) to calculate the cost-effectiveness of prehospital HEMS Abx. The design of the study was a prospective, nonrandomized, nonintervention, natural study of timing and clinical outcomes for patients with suspected open extremity fracture. There were 138 scene trauma cases transported by 8 participating HEMS programs from July 2009 to June 2010. The participating HEMS programs were both urban and rural. The diagnosis of an open fracture by the HEMS crews had an accuracy rate of 97.8% (95% confidence interval, 90.8%-98.4%). The time from the incident to Abx was 30 minutes shorter (P = .0001) when Abx were administered by HEMS crews. There was no statistical significance (P = 1.0) regarding the endpoint of infection or nonunion development in HEMS- versus hospital-administered Abx. In conclusion, the administration of Abx by HEMS crews to patients diagnosed with open extremity fractures is feasible, it may decrease the time to Abx by 30 minutes, and the effect magnitude (40.3% relative risk reduction) was promising.

A Review of Transbuccal Fentanyl Use in the Emergency Department

Patients with severe, painful injuries and illnesses treated in the emergency department are commonly administered opioid medications. Intravenous administration provides the most rapid onset of pain relief and is readily titrated. Fentanyl, administered intravenously, is well documented as an effective medication for pain management in the emergency department. It is preferred in many settings due to its minimal hemodynamic effects, as compared to other commonly used opioids. However, not all patients require intravenous access. These patients are given orally administered pain medications. The oral route is effective at minimizing pain but has a much slower onset of action when compared to the intravenous route. As an alternative to the slower onset of action seen with oral opioids, this paper discusses the use of fentanyl buccal tablet for pain management in the emergency department. Fentanyl buccal tablets are readily absorbed, with a bioavailability of approximately 65%, and have a more rapid onset of action than achieved with traditional oral opioids used in the emergency department.

EMS Stretcher "Misadventures" in a Large, Urban EMS System: A Descriptive Analysis of Contributing Factors and Resultant Injuries

Purpose. There is a paucity of data regarding EMS stretcher-operation-related injuries. This study describes and analyzes characteristics associated with undesirable stretcher operations, with or without resultant injury in a large, urban EMS agency. Methods. In the study agency, all stretcher-related “misadventures” are required to be documented, regardless of whether injury results. All stretcher-related reports between July 1, 2009 and June 30, 2010 were queried in retrospective analysis, avoiding Hawthorne effect in stretcher operations. Results. During the year studied, 129,110 patients were transported. 23 stretcher incidents were reported (0.16 per 1,000 transports). No patient injury occurred. Four EMS providers sustained minor injuries. Among contributing aspects, the most common involved operations surrounding the stretcher-ambulance safety latch, 14/23 (60.9%). From a personnel injury prevention perspective, there exists a significant relationship between combative patients and crew injury related to stretcher operation, Fishers exact test 0.048. Conclusions. In this large, urban EMS system, the incidence of injury related to stretcher operations in the one-year study period is markedly low, with few personnel injuries and no patient injuries incurred. Safety for EMS personnel and patients could be advanced by educational initiatives that highlight specific events and conditions contributing to stretcher-related adverse events.

Subcutaneous Fluid Administration: A Potentially Useful Tool in Prehospital Care

Mass casualty incidents (MCIs) and disaster medical situations are ideal settings in which there is need for a novel approach to infusing fluids and medications into a patients intravascular space. An attractive new approach would avoid the potentially time-consuming needlestick and venous cannulation requiring a trained practitioner. In multiple-patient situations, trained practitioners are not always available in sufficient numbers to enable timely placement of intravenous catheters. The novel approach for intravascular space infusion, described in this paper involves the preadministration of the enzyme, human recombinant hyaluronidase (HRH), into the subcutaneous (SC) space, via an indwelling catheter. The enzyme “loosens” the SC space effectively enhancing the absorption of fluids and medication.

Identifying Patient Door-to-Room Goals to Minimize Left-Without-Being-Seen Rates

Introduction Emergency department (ED) patients in the leave-without-being-seen (LWBS) group risk problems of inefficiency, medical risk, and financial loss. The goal at our hospital is to limit LWBS to <1%. This study’s goal was to assess the influence on LWBS associated with prolonging intervals between patient presentation and placement in an exam room (DoorRoom time). This study’s major aim was to identify DoorRoom cutoffs that maximize likelihood of meeting the LWBS goal (i.e. <1%). Methods We conducted the study over one year (8/13–8/14) using operations data for an ED with annual census ~50,000. For each study day, the LWBS endpoint (i.e. was LWBS <1%: “yes or no”) and the mean DoorRoom time were recorded. We categorized DoorRoom means by intervals starting with ≤10min and ending at >60min. Multivariate logistic regression was used to assess for DoorRoom cutoffs predicting high LWBS, while adjusting for patient acuity (triage scores and admission %) and operations parameters. We used predictive marginal probability to assess utility of the regression-generated cutoffs. We defined statistical significance at p<0.05 and report odds ratio (OR) and 95% confidence intervals (CI). Results Univariate results suggested a primary DoorRoom cutoff of 20′, to maintain a high likelihood (>85%) of meeting the LWBS goal. A secondary DoorRoom cutoff was indicated at 35′, to prevent a precipitous drop-off in likelihood of meeting the LWBS goal, from 61.1% at 35′ to 34.4% at 40′. Predictive marginal analysis using multivariate techniques to control for operational and patient-acuity factors confirmed the 20′ and 35′ cutoffs as significant (p<0.001). Days with DoorRoom between 21–35′ were 74% less likely to meet the LWBS goal than days with DoorRoom ≤20′ (OR 0.26, 95% CI [0.13–0.53]). Days with DoorRoom >35′ were a further 75% less likely to meet the LWBS goal than days with DoorRoom of 21–35′ (OR 0.25, 95% CI [0.15–0.41]). Conclusion Operationally useful DoorRoom cutoffs can be identified, which allow for rational establishment of performance goals for the ED attempting to minimize LWBS.

Mathematical Modeling of the Impact of Hospital Occupancy: When Do Dwindling Hospital Beds Cause ED Gridlock?

Objectives. The time emergency department (ED) patients spend from presentation to admittance is known as their length of stay (LOS). This study aimed to quantify the inpatient occupancy rate (InptOcc)/ED LOS relationship and develop a methodology for identifying resource-allocation triggers using InptOcc-LOS association-curve inflection points. Methods. This study was conducted over 200 consecutive days at a 700-bed hospital with an annual ED census of approximately 50,000 using multivariate spline (piecewise) regression to model the InptOcc/LOS relationship while adjusting for confounding covariates. Nonlinear modeling was used to assess for InptOcc/LOS associations and determine the inflection point where InptOcc profoundly impacted LOS. Results. At lower InptOcc, there was no association. Once InptOcc reached ≥88%, there was a strong InptOcc/LOS association; each 1% InptOcc increase predicted a 16-minute (95% CI, 12–20 minutes) LOS prolongation, while the confounder-adjusted analysis showed each 1% InptOcc increase >89% precipitating a 13-minute (95% CI, 10–16 minutes) LOS prolongation. Conclusions. The study hospital’s InptOcc was a significant predictor of prolonged ED LOS beyond the identified inflection point. Spline regression analysis identified a clear inflection point in the InptOcc-LOS curve that potentially identified a point at which to optimize inpatient bed availability to prevent increased costs of prolonged LOS.