Eric R. Swanson

Clinical comparison of ocular irrigation fluids following chemical injury

This study tested the hypothesis that four ocular irrigating solutions were equally irritating during copious irrigation. We conducted a prospective, double-blind study of patients with chemical exposure to the eye. Each underwent cross-over irrigation with all of the following in random order: normal saline (NS), lactated Ringers (LR), normal saline adjusted to pH 7.4 with sodium bicarbonate (NS + Bicarb), and Balanced Saline Solution Plus (BSS Plus, Alcon Laboratories, Fort Worth, TX). Compared with traditional NS and LR, NS + Bicarb tended to be more comfortable. BSS Plus was statistically superior (P less than .05) to NS and preferred over LR and NS + Bicarb. Three patients demanded discontinuance of NS or NS + Bicarb infusions. All solutions had comparable normalization of conjunctival pH and degree of injection. Alternate solutions including BSS Plus should be considered for use in those patients whose poor tolerance to normal saline threatens to delay or interrupt eye irrigation following a chemical injury.

The use of etomidate for rapid-sequence intubation in the air medical setting.

Objective. To describe the use of etomidate for rapid-sequence intubation (RSI) in the air medical environment. Methods. This was a retrospective review of a consecutive series of patients receiving etomidate for RSI by a university hospital-based air medical program. Records of all patients more than 10 years of age requiring intubation during a 13-month period were reviewed. Data collected included demographics, site of intubation, person performing intubation, indication, diagnosis, medications administered, complications, and pre- and post-RSI vital signs. Results. Of 79 patients who underwent intubation, 53 (67%) received etomidate for RSI. Forty-two (79%) patients who received etomidate were also given succinylcholine. The overall intubation success rate was 96%. Two patients required a cricothyrotomy. Hemodynamic data were complete for 46 patients. The average systolic blood pressures (SBPs) were 139.11 ± 31.21 mm Hg prior to RSI and 137.85 ± 32.00 mm Hg after RSI. These were not significantly different (p = 0.82). The mean change in SBP was −1.26 ± 37.03 mm Hg (95% CI −6.61 to 4.09). The average heart rates (HRs) were 101.59 ± 23.95 beats/min prior to RSI and 97.76 ± 23.45 beats/min after RSI. These were also not significantly different (p = 0.15). The mean change in HR was −3.52 ± 15.67 beats/min (95% CI −5.79 to −1.26). Conclusion. This study supports the safety of etomidate for RSI in the air medical setting. The intubation success rate was comparable to those in other studies evaluating RSI. There was no significant change in average SBP or HR during RSI.

Cricothyrotomy in air medical transport.

BACKGROUND Airway management is an essential skill for air medical transport (AMT) providers. The endpoint of airway maneuvers is a cricothyrotomy which may be live-saving if other measures fail. We reviewed cricothyrotomy cases in our AMT program to evaluate the success rate and the circumstances surrounding the procedure. METHODS This was a retrospective review of cases in which a cricothyrotomy was performed at the University of Utah AirMed flight program during the years of 1995 to 2004. Data included incidence, indications, complications, neurologic outcome, and success rates of the procedure. RESULTS Of the 14,994 transports during the study period, 17 cricothyrotomies were performed. Airway obstruction by blood and/or vomit was the most frequent indication (47%) followed by airway edema/distorted anatomy (24%). The total number of cricothyrotomies decreased during the study period. Seven (41%) patients survived with a reasonable neurologic outcome. The remaining 10 patients died during initial treatment or subsequent hospitalization. Success rate of the procedure in our series was 100%. These results were compared with those of other cricothyrotomy studies. CONCLUSION Cricothyrotomy has become less common as an emergency rescue technique. However, AMT personnel have a high success rate when performing the cricothyrotomy procedure. This rate is as high as or higher than other emergency personnel.

Effect of an airway education program on prehospital intubation

INTRODUCTION The purpose of this study was to determine the impact of an airway education program (AEP) on prehospital intubation. SETTING University-based air medical program METHODS Retrospective review of 372 consecutive intubations for 3 years before and 3 years after the institution of an AEP. Descriptive statistics were used and comparisons were made using chi-square analysis. RESULTS Intubation success rate was 170/180 (94%) for the preAEP group and 186/192 (97%) for the postAEP group (P > 0.05). Neuromuscular blockade (NMB) was used in 113/180 (63%) of preAEP intubations and 145/192 (76%) of postAEP intubations (P < 0.01). NMB without sedation decreased from 62/113 (55%) in the preAEP group to 12/145 (8%) in the postAEP group (P < 0.001). Cricothyrotomy rate decreased from 10/180 (6%) in the preAEP group to 3/192 (2%) in the postAEP group (P < 0.05). Failed intubation rate in nonarrested patients during the 6-year period was 10/154 (6%) in patients receiving no medications or partial rapid sequence intubation (RSI) compared with 3/184 (2%) in patients who had full RSI (P < 0.025). CONCLUSION Establishment of an AEP resulted in an increase in NMB for intubation, a dramatic decrease in the use of NMB without sedation, and a decrease in cricothyrotomy rate. The rate of intubation failure in nonarrested patients was higher in those who received no medications or partial RSI compared with full RSI.

Outcomes of pediatric trauma patients transported from rural and urban scenes

OBJECTIVES Mortality differences exist between victims of urban and rural trauma. It is unknown if these differences persist in those patients who survive to HEMS transport. This study examined the in-hospital mortality, hospital LOS, and discharge status of pediatric blunt trauma victims transported by HEMS from rural and urban scenes. METHODS Retrospective review of pediatric (< 17) transports between 1997 and 2001. 130 rural and 419 urban pediatric patients transported to area trauma centers were identified from HEMS and registry records. RESULTS Total mileage, flight times, and scene times were significantly longer for rural flights (P < 0.05). There were no significant differences between the groups with regard to age, gender, vitals, hospital/ICU days, and mortality. After controlling for ISS and mechanism of injury, urban patients were 9 times more likely to die compared to rural patients. CONCLUSIONS Pediatric patients injured in urban areas had shorter total flight and scene times than pediatric patients flown from rural scenes. Higher adjusted in-hospital mortality rates in the urban group were likely a result of faster EMS response and transport times, which minimized out-of-hospital deaths. Factors prior to HEMS arrival may have more impact on the increased mortality rates of rural blunt trauma victims documented nationally.

Outcomes of Blunt Trauma Victims Transported by HEMS from Rural and Urban Scenes

Objective. Mortality differences exist between victims of urban andrural trauma; however, it is unknown if these differences persist in those patients who survive to HEMS transport. This study examined the in-hospital mortality, length of hospital stay, anddischarge status of adult blunt trauma victims transported by HEMS from rural andurban scenes to regional trauma centers. Methods. Retrospective review of all adult (age ≥ 15) HEMS transports in 2001; 271 urban and141 rural blunt trauma patients were identified from HEMS transport records andthe trauma registries at three level one trauma centers. Demographic data, scene andhospital interventions, as well as discharge status of the two groups were examined. Results. Total mileage [27 ± 12 vs. 119 ± 64, p < 0.001], total flight times (minutes) [30 ± 10 vs. 79 ± 40, p < 0.001], andscene times (minutes) [16 ± 8 vs. 21 ± 14, p < 0.001] were significantly longer for rural flights. There were no significant differences between the groups with regard to age, gender, receiving hospital, andinitial HEMS vitals. Injury Severity Score, ICU length of stay (LOS), total hospital LOS, andhospital mortality did not differ between the two groups. After controlling for age, gender, andISS, there were no significant mortality differences between the two groups (p = 0.074). Conclusions. Despite longer flight andscene times for rural patients, adjusted in-hospital mortality rates were similar for patients transported from urban andrural scenes. Factors prior to HEMS arrival may contribute to increased mortality rates of rural blunt trauma victims documented nationally.

Location of Airway Management in Air Medical Transport

Background. Prehospital providers are constantly challenged with the task of managing airways in unpredictable andoften inhospitable environments. Air medical transport (AMT) crews must be prepared to work in restrictive spaces with limited resources while in the aircraft. This study examines flight crew success rate andcircumstances surrounding airway management in different locations. Methods. This was a retrospective analysis of intubations performed by a university-based air medical transport team from January 1, 1995, to May 31, 2007. Patient records andprospectively gathered airway management quality assurance data were reviewed for location of intubation, patient characteristics, andsuccess rates. Success was defined as placing a cuffed tube in the trachea nonsurgically. Results. Nine hundred thirty-eight patients required 939 advanced airway management procedures, and936 cases had information sufficient for analysis. Six hundred twenty-seven (67%) of these intubations took place on scene, 235 (25.1%) at the referring hospital, 67 en-route (7.2%), andseven (0.7%) at the receiving hospital. The overall intubation success rate was 96% andthe highest rate was for hospital intubations (98.8%), followed by scene (94.9%) anden-route (89.6%) airway encounters. Intubation success was more likely in the hospital setting (odds ratio [OR] = 8.7, 95% confidence interval [CI] 2.2–35.0, p = 0.002] andon the scene [OR = 2.3, 95% CI 0.95–5.7, p = 0.065] compared with those en-route. Unanticipated patient deterioration was noted as the most common reason for in-flight airway management. Type of aircraft was not significantly associated with intubation success (p = 0.132). Conclusions. Airway management was performed with a high success rate in a variety of locations andpatient characteristics by our air medical crew. When in the hospital environment, flight crew success rates were comparable to those of other emergency personnel. Caution should be used, however, when considering intubating in-flight because of slightly lower success rates.

Air Ambulance Transport Times and Advanced Cardiac Life Support Interventions during the Interfacility Transfer of Patients with Acute ST-segment Elevation Myocardial Infarction

Abstract Objectives. To characterize transport times for the interfacility air ambulance transport of patients with acute ST-segment elevation myocardial infarction (STEMI), to estimate the proportion of patients at risk of in-transport clinical decompensation, and to explore associated risk factors for such. Methods. The electronic medical records of 35 air ambulance programs in the United States from December 2003 through December 2008 were reviewed. We defined clinical decompensation during transport as the combined outcome of either cardiopulmonary arrest or the receipt of any of a prespecified set of advanced life support (ALS) interventions. Multiple logistic regression employing generalized estimating equations to model autocorrelation of measures within air ambulance programs was used to explore the relationship between time from dispatch to transport and the outcome of interest. Results. Three thousand seven hundred sixty-seven transports of STEMI patients were identified during the period of interest. Eighty-five percent of rotor wing transports (median 80 minutes, interquartile range [IQR] 66–104) and 7% of fixed-wing transports (median 162 minutes, IQR 142–210) attained a total transfer time of ≤2 hours. Clinical decompensation in transport occurred in 182 of 3,767 (4.8%, 95% confidence interval [CI] 4.2–5.6%) transports. The most frequent critical ALS interventions were the administration of antiarrhythmics and the initiation of vasopressors. The odds ratios (ORs) for clinical decompensation comparing higher pretransport time quartiles with the lowest quartile (i.e., Q1: 6–50 minutes) were as follows: Q4: 82–1,500 minutes, OR 2.5 (95% CI 1.3–4.8, p = 0.007); Q3: 64–81 minutes, OR 1.9 (95% CI 1.0–3.6, p = 0.0499); and Q2: 51–63 minutes, OR 1.45 (95% CI 0.7–3.1, p = 0.34). Cardiac arrest or need for an ALS intervention prior to transport and a history of diabetes were also predictive of the outcome of interest. Conclusions. The majority of interfacility rotor-wing air ambulance transfers of patients with STEMI achieved a total transfer time of ≤2 hours. Clinical decompensation requiring ALS treatment occurred in a small percentage of patients. Diabetes, prior arrest or decompensation, and delays to transport were associated with clinical decompensation in the air. Efforts to reduce delays to transport may reduce this risk in transported patients.

Anthrax threats: a report of two incidents from Salt Lake City.

The threat of anthrax as an agent of bioterrorism in the U.S. is very real, with 47 incidents of possible exposure involving 5664 persons documented by the Federal Bureau of Investigation over a 14-month period in 1998 and 1999. The highly visible and potentially devastating effects of these threats require a well-coordinated and well-organized Emergency Medical Services (EMS) and Emergency Department (ED) response to minimize panic and reduce the potential spread of an active and deadly biologic agent. This requires planning and education before the event. We describe the events of two anthrax threats in a major metropolitan area. The appropriate EMS and ED response to these threats is outlined.

Pain medication use before ED arrival

The objective of this study was to determine the frequency and types of pain medications taken before ED arrival based on pain intensity, duration of pain, chief complaint, gender, age, and race. A convenience sample of patients in pain was enrolled in this university hospital-based prospective, observational study. A total of 1233 patients were enrolled. Five hundred thirty-nine of 1233 (44%) patients took pain medication before arrival. Two hundred three (38%) took ibuprofen, 147 of 539 (27%) took oral opioids, and 135 of 539 (25%) took acetaminophen, which were the most frequently used medications. Severity of pain, age, duration of pain, and chief complaint were associated (chi-squared P <.05) with variations in prior medication use. Race and gender were not associated (chi-squared P >.05) with differences in medication use before arrival. Many patients (44%) take medication before arrival in the ED. Age, severity and duration of pain, as well as chief complaint are associated with differences in frequency of self-administered medication.