Prehospital oral endotracheal intubation by rural basic emergency medical technicians.

STUDY OBJECTIVE: To determine whether basic emergency medical technicians (EMT-B) can perform prehospital oral endotracheal intubation with success rates comparable to those of paramedics. METHODS: This was a nonrandomized, controlled trial using historical controls. Seven basic life support emergency medical services systems in six counties and their corresponding emergency departments in rural Indiana participated. Eighty-seven full-time EMTs with no prior or concurrent paramedic training volunteered for intubation training. Apneic prehospital patients aged 16 years or older without an active gag reflex or massive facial trauma were eligible for intubation and study enrollment. The EMTs completed a 9-hour didactic and airway manikin training course in direct laryngoscopic endotracheal intubation. The course was adapted from the national paramedic curriculum. RESULTS: Thirty-four (39%) of the EMT-Bs attempted to intubate 57 eligible patients. In 49.1% of these patients, successful endotracheal tube placement was confirmed by the receiving physician (95% confidence interval, 36.4% to 61.9%); in contrast, the prehospital intubation success rates from three previous studies of manikin-trained paramedics ranged from 76.9% to 90.6% (P < .001). Complications included five (9%) inadvertent extubations, two endotracheal tube cuff ruptures, two prolonged intubation attempts, and one mainstem bronchus intubation. There were no unrecognized esophageal intubations. Two of the seven EMS agencies did not report any intubation data. CONCLUSION: Rural EMTs with didactic and airway manikin training failed to achieve prehospital intubation success rates comparable to those of paramedic controls. Possible explanations include training deficiencies, poor skill transference from manikin to human intubation, infrequent intubation experiences, and inconsistent supervision.

Prehospital pearls, pitfalls, and updates.

The rapid proliferation of emergency medical services in the United States has led to numerous controversies concerning delivery, interventions, and efficacy. This article presents a brief overview of the important literature in this expanding field. Important clinical topics, including first-responder defibrillation, rapid sequence intubation, and airway management, are reviewed. In addition, several important medicolegal topics pertaining to pre-hospital care are analyzed.

Pain and tissue-interface pressures during spine-board immobilization.

STUDY OBJECTIVES: Although spine boards are one of the main EMS means of immobilization and transportation, few studies have addressed the discomfort and potential harmful consequences of using this common EMS tool. We compared the levels of pain and tissue-interface (contact) pressures in volunteers immobilized on spine boards with and without interposed air mattresses. DESIGN: Prospective crossover study. SETTING: Emergency department of Methodist Hospital of Indiana, Indianapolis, Indiana. PARTICIPANTS: Twenty healthy volunteers who had not taken any analgesic drugs in the preceding 24 hours, were not experiencing any pain at the time of the study, and did not have history of chronic back pain. INTERVENTIONS: To simulate prehospital transport conditions, we immobilized volunteers with hard cervical collars and single-buckle chest straps on wooden spine boards with or without commercially available medical air mattresses. The crossover order was randomized. After 80 minutes, immobilization measures were discontinued and the subjects were allowed to get off the boards for a recovery period of 60 minutes. Subjects were then studied for a second 80-minute period with the opposite intervention. At baseline and at 20-minute intervals, the level of pain was rated with a 100-mm visual analog scale. Tissue-interface pressures were measured at the occiput, sacrum, and left heel. RESULTS: Mean pain on the visual analog scale was 9.7 mm at the end of the mattress period and 37.5 mm at the end of the no-mattress period (P = .0001). Although there were no significant differences in pain between the two groups at time 0, volunteers reported significantly more pain during the no-mattress period at 20 (P = .003), 40 (P = .0001), and 60 minutes (P = .0001). All 20 subjects reported that immobilization on the spine board with the mattress was "much better" (five-point scale) than that without the mattress. Interface pressure levels were significantly less in the mattress period than in the no-mattress period measured at occiput (P = .0001), sacrum (P = .0001), and heel (P = .0001). CONCLUSION: In a simulated immobilization experiment, healthy volunteers reported significantly less pain during immobilization on a spine board with an interposed air mattress than during that on a spine board without a mattress. Tissue-interface pressures were significantly higher on spine boards without air mattresses. This and previous studies suggest that immobilization on rigid spine boards is painful and may produce tissue-interface pressure high enough to result in the development of pressure necrosis ("bedsores"). Emergency care providers should consider the use of interposed air mattresses to reduce the pain and potential tissue injury associated with immobilization on rigid spine boards.

Does anybody really know what time it is? Does anybody really care?

STUDY OBJECTIVE: To evaluate the difference among time sources in an emergency medical system. DESIGN: Prospective; comparison to a criterion standard. SETTING: Five emergency departments and three emergency medical services systems in Indianapolis, Indiana. INTERVENTIONS: Coordinated Universal Time (UTC), generated by the atomic clock in Boulder, Colorado, and broadcast by the US Commerce Department's National Institute of Standards and Technology, was used as the time standard. The investigators, on a single day, made unannounced visits to the five EDs and the ambulances and fire stations in the three emergency medical services systems. The times displayed on all time sources at each location were recorded. The accuracy to the second of each time source compared to UTC was calculated. RESULTS: Three time sources were excluded (two defibrillator clocks and one ED wall clock that varied more than three hours from UTC). Of the 152 time sources, 72 had analog displays, 74 digital, three both, and three other. The average absolute difference from UTC was 1 minute 45 seconds (SEM, 9 seconds) with a range of 12 minutes 34 seconds slow to 7 minutes 7 seconds fast. Thus, two timepieces could have varied by as much as 19 minutes 41 seconds. Compared to UTC, 47 timepieces (31%) were slow, 100 (66%) were fast, and five (3%) were accurate to the second. Fifty-five percent of the time sources varied one minute or more from UTC. CONCLUSION: Time sources in this health care system varied considerably. Time recording in medicine could be made more precise by synchronizing medical clocks to UTC, using computers to automatically "time stamp" data entries and using only digital time sources with second displays.

Disorders of calcium and magnesium metabolism.

Although relatively common, aberrations in divalent cation homeostasis may be overlooked in Emergency Department patients. The intracellular concentration of ionized calcium is the major regulator of cellular function. Patients may present with signs and symptoms of deranged calcium homeostasis that range from the mild and nonspecific to the truly life threatening. Critically ill patients may develop profound, life-threatening hypocalcemia either as a result of their underlying illness or as a complication of resuscitation. Patients with hypercalcemia may present with symptoms that are so vague and nonspecific that the diagnosis may not be considered. An understanding of the pathophysiology of calcium metabolism allows the emergency physician to identify patients at risk for abnormal calcium homeostasis, and to intervene in an appropriate manner. Magnesium is an essential cofactor in a host of important biochemical reactions. Magnesium deficiency is fairly common in certain groups of patients and can cause serious complications. The diagnosis is often difficult to make in the Emergency Department setting. The emergency physician should be aware of clinical situations that predispose to magnesium deficiency and be prepared to institute empiric therapy if indicated. Severe hypermagnesemia is rather uncommonly encountered in the Emergency Department. The magnesium ion is an effective calcium channel blocker, and patients with severe hypermagnesemia develop profound cardiovascular and neuromuscular dysfunction as a result. In pharmacologic doses, magnesium's unique calcium channel antagonism may be clinically useful, and there is growing interest in its potential use as an antiarrhythmic, anticonvulsant, and smooth muscle relaxant.