Geoff Stroh

Intranasal naloxone is a viable alternative to intravenous naloxone for prehospital narcotic overdose.

Objective. To compare the prehospital time intervals from patient contact and medication administration to clinical response for intranasal (IN) versus intravenous (IV) naloxone in patients with suspected narcotic overdose. Methods. This was a retrospective review of emergency medical services (EMS) and hospital records, before and after implementation of a protocol for administration of intranasal naloxone by the Central California EMS Agency. We included patients with suspected narcotic overdose treated in the prehospital setting over 17 months, between March 2003 and July 2004. Paramedics documented dose, route of administration, and positive response times using an electronic record. Clinical response was defined as an increase in respiratory rate (breaths/min) or Glasgow Coma Scale score of at least 6. Main outcome variables included time from medication to clinical response and time from patient contact to clinical response. Secondary variables included numbers of doses administered and rescue doses given by an alternate route. Between-group comparisons were accomplished using t-tests and chi-square tests as appropriate. Results. One hundred fifty-four patients met the inclusion criteria, including 104 treated with IV and 50 treated with IN naloxone. Clinical response was noted in 33 (66%) and 58 (56%) of the IN and IV groups, respectively (p = 0.3). The mean time between naloxone administration and clinical response was longer for the IN group (12.9 vs. 8.1 min, p = 0.02). However, the mean times from patient contact to clinical response were not significantly different between the IN and IV groups (20.3 vs. 20.7 min, p = 0.9). More patients in the IN group received two doses of naloxone (34% vs. 18%, p = 0.05), and three patients in the IN group received a subsequent dose of IV or IM naloxone. Conclusions. The time from dose administration to clinical response for naloxone was longer for the IN route, but the overall time from patient contact to response was the same for the IV and IN routes. Given the difficulty and potential hazards in obtaining IV access in many patients with narcotic overdose, IN naloxone appears to be a useful and potentially safer alternative.

Biphasic Defibrillation Does not Improve Outcomes Compared to Monophasic Defibrillation in Out-of-Hospital Cardiac Arrest

Study Objective. To compare the outcomes of out-of hospital cardiac arrest (OHCA) victims treated with monophasic truncated exponential (MTE) versus biphasic truncated exponential (BTE) defibrillation in an urban EMS system. Methods. We conducted a retrospective review of electronic prehospital andhospital records for victims of OHCA between August 2000 andJuly 2004, including two years before andafter implementation of biphasic defibrillators by the Fresno County EMS agency. Main outcome measures included: return of spontaneous circulation (ROSC), number of defibrillations required for ROSC, survival to hospital discharge, anddischarge to home versus an extended care facility. Results. There were 485 cases of cardiac arrest included. Baseline characteristics between the monophasic andbiphasic groups were similar. ROSC was achieved in 77 (30.6%, 95% CI 25.2–36.5%) of 252 patients in the monophasic group, andin 70 (30.0% 95% CI 24.5–36.2%) of 233 in the biphasic group (p =. 92). Survival to hospital discharge was 12.3% (95% CI 8.8–17%) for monophasic and10.3% (95% CI 7.0–14.9%) for biphasic (p =. 57). Discharge to home was accomplished in 20 (7.9%, 95% CI 5.1–12.0%) of the monophasic, andin 15 (6.4%, 95% CI 3.9–10.4%) of the biphasic group (p =. 60). More defibrillations were required to achieve ROSC (3.5 vs. 2.6, p =. 015) in the monophasic group. Conclusions. We found no difference in ROSC or survival to hospital discharge between MTE andBTE defibrillation in the treatment of OHCA, although fewer defibrillations were required to achieve ROSC in those treated with biphasic defibrillation.

An Experimental Study of Warming Intravenous Fluid in a Cold Environment

Abstract Objective.—Numerous studies support the use of warmed intravenous fluids in hypothermic patients. The most effective method to accomplish this goal in a cold prehospital, wilderness, or combat setting is unknown. We evaluated various methods of warming intravenous fluids for a bolus infusion in a cold remote environment. Methods.—One liter and 500 mL bags of intravenous fluid at 5°C were heated using various methods in a 5°C cold room. Methods included attachment of 3 types of chemical heat packs and heating the fluid in a pot on a camping stove. For all methods, fluids were run at a wide-open rate through an intravenous line with an 18-gauge catheter attached to the end to simulate a bolus infusion. The temperature of the fluid at the end of the intravenous line was measured. Each method was tested twice. Equipment weight and setup times are reported. Mean infusion temperatures for the various methods are compared. Results.—Equipment weights ranged from 19 to 665 gm. Setup times ranged from 5 to 11 minutes. The 2 methods which achieved the desired mean infusion temperature of 35 to 42°C without excessive maximum temperatures were 1) 2 Meal Ready to Eat hot packs attached to a 500 mL bag of fluid for 10 minutes prior to infusion, and 2) a camping stove heating the surface of a 500 mL bag of fluid to 75°C prior to infusion. Other methods, including the use of commonly available heat packs and a commercially available IV fluid warmer were ineffective, with mean infusion temperatures ranging from 7 to 12°C. Conclusions.—Heating of cold intravenous fluids in a cold environment is possible using either Meal Ready to Eat heat packs or a camping stove. Further study is needed to evaluate the ability of either method to consistently produce an appropriate fluid temperature given various ambient and initial fluid temperatures.

A Lightning Multiple Casualty Incident in Sequoia and Kings Canyon National Parks

Multiple casualty incidents (MCIs) are uncommon in remote wilderness settings. This is a case report of a lightning strike on a Boy Scout troop hiking through Sequoia and Kings Canyon National Parks (SEKI), in which the lightning storm hindered rescue efforts. The purpose of this study was to review the response to a lightning-caused MCI in a wilderness setting, address lightning injury as it relates to field management, and discuss evacuation options in inclement weather incidents occurring in remote locations. An analysis of SEKI search and rescue data and a review of current literature were performed. A lightning strike at 10,600 feet elevation in the Sierra Nevada Mountains affected a party of 5 adults and 7 Boy Scouts (age range 12 to 17 years old). Resources mobilized for the rescue included 5 helicopters, 2 ambulances, 2 hospitals, and 15 field and 14 logistical support personnel. The incident was managed from strike to scene clearance in 4 hours and 20 minutes. There were 2 fatalities, 1 on scene and 1 in the hospital. Storm conditions complicated on-scene communication and evacuation efforts. Exposure to ongoing lightning and a remote wilderness location affected both victims and rescuers in a lightning MCI. Helicopters, the main vehicles of wilderness rescue in SEKI, can be limited by weather, daylight, and terrain. Redundancies in communication systems are vital for episodes of radio failure. Reverse triage should be implemented in lightning injury MCIs. Education of both wilderness travelers and rescuers regarding these issues should be pursued.

Hot and Cold Drugs: National Park Service Medication Stability at the Extremes of Temperature

Abstract Study Objective: National Park Service (NPS) Parkmedics provide medical care in austere environments. The objective of this study was to evaluate the stability of specific medications used by Parkmedics at extremes of temperatures likely to be faced in the field. Methods: This is a bench research study conducted in the laboratory setting over a 4-week period. Parenteral medications were separated into 4 temperature exposure groups: A) 45°C (hot); B) −20°C (cold); C) hot then cold temperatures alternating weekly; and D) cold then hot temperatures alternating weekly. At study start and the end of each week, three aliquots from each group were sampled to determine the remaining drug concentration through liquid chromatography-quadrupole time-of-flight mass spectrometry (Agilent LC 1260- QTOF/MS 6550). Quantitative analysis was done using Agilent MassHunter Quantitative Analysis software. The mean drug concentration from triplicate aliquots was expressed as percentage of its baseline concentration to monitor the drugs stability during storage. Results: Eight medications were analyzed (atropine, diphenhydramine, fentanyl, hydromorphone, midazolam, morphine, naloxone, ondansetron). Hydromorphone, morphine, and ondansetron showed the greatest stability, at above 90% of original concentration in all study arms. Diphenhydramine, fentanyl and midazolam showed heat independent degradation, degrading the same way regardless of heat exposure. By the end of the study period, 51–56% midazolam remained in all groups. Atropine and naloxone showed heat dependent degradation, degrading more when exposed to heat. Atropine had the most degradation, being undetectable after 4 weeks of heat exposure. Conclusions: We recommend that EMS providers replace atropine, naloxone, diphenhydramine, fentanyl, and midazolam frequently if they are practicing in low call volume or high-temperature environments. Further studies will be needed to determine if re-dosing midazolam, naloxone, and atropine is the appropriate clinical strategy in this setting if adequate clinical effect is not reached with a single dose.

Pediatric Tape: Accuracy and Medication Delivery in the National Park Service.

Introduction The objective is to evaluate the accuracy of medication dosing and the time to medication administration in the prehospital setting using a novel length-based pediatric emergency resuscitation tape. Methods This study was a two-period, two-treatment crossover trial using simulated pediatric patients in the prehospital setting. Each participant was presented with two emergent scenarios; participants were randomized to which case they encountered first, and to which case used the National Park Service (NPS) emergency medical services (EMS) length-based pediatric emergency resuscitation tape. In the control (without tape) case, providers used standard methods to determine medication dosing (e.g. asking parents to estimate the patient’s weight); in the intervention (with tape) case, they used the NPS EMS length-based pediatric emergency resuscitation tape. Each scenario required dosing two medications (Case 1 [febrile seizure] required midazolam and acetaminophen; Case 2 [anaphylactic reaction] required epinephrine and diphenhydramine). Twenty NPS EMS providers, trained at the Parkmedic/Advanced Emergency Medical Technician level, served as study participants. Results The only medication errors that occurred were in the control (no tape) group (without tape: 5 vs. with tape: 0, p=0.024). Time to determination of medication dose was significantly shorter in the intervention (with tape) group than the control (without tape) group, for three of the four medications used. In case 1, time to both midazolam and acetaminophen was significantly faster in the intervention (with tape) group (midazolam: 8.3 vs. 28.9 seconds, p=0.005; acetaminophen: 28.6 seconds vs. 50.6 seconds, p=0.036). In case 2, time to epinephrine did not differ (23.3 seconds vs. 22.9 seconds, p=0.96), while time to diphenhydramine was significantly shorter in the intervention (with tape) group (13 seconds vs. 37.5 seconds, p<0.05). Conclusion Use of a length-based pediatric emergency resuscitation tape in the prehospital setting was associated with significantly fewer dosing errors and faster time-to-medication administration in simulated pediatric emergencies. Further research in a clinical field setting to prospectively confirm these findings is needed.

Emergency Medical Services and Remote Medical Oversight in Sequoia and Kings Canyon National Parks, 2011–2013

INTRODUCTION The University of California San Francisco Fresno Department of Emergency Medicine provides base hospital support for the Sequoia and Kings Canyon National Parks (SEKI) emergency medical services (EMS) system. This descriptive epidemiologic study reports reasons the park EMS system is used and interventions provided, detailing the nature of patient encounters, type and frequency of injuries and interventions, reasons for base hospital contact, and patient dispositions. METHODS Patient charts for all EMS encounters in SEKI from 2011 to 2013 were included, and relevant data were extracted by a single reviewer. RESULTS Of the 704 charts reviewed, 570 (81%) were frontcountry patient encounters (within 1.6 km [1 mi] of a paved road); 100 (14%) were backcountry; and 34 (5%) occurred in undefined locations. Regarding sex and age, 58% of patients were men; 22% were younger than 18 y, and 15% were 65 y or older. More than 80% of calls occurred during the months of June through August. The most common complaints were extremity trauma (24%), torso trauma (13%), and lacerations (9%). Almost 50% of patients were transferred to a higher level of care. Medications were administered to 37% of patients, with oxygen being the most common. Procedures were performed 49% of the time, primarily intravenous access and splinting. Base hospital contact was made 38% of the time, most commonly (54%) for advice regarding disposition. CONCLUSIONS SEKI EMS providers encounter a wide variety of patients in various settings, including the backcountry. Resource allocation, training, and protocol development should be tailored to meet their needs.