Inhaled nitrous oxide versus placebo as an analgesic and anxiolytic adjunct to peripheral intravenous cannulation.

The objective was to determine whether an inhaled 50:50 mixture of nitrous oxide and oxygen (N(2)O/O(2)) provides significant pain and anxiety relief during intravenous cannulation in healthy adults. The study was conducted at the ED of a military teaching hospital. Participants included adult volunteers aged 18 to 50 years. Excluded were those with allergy to N(2)O, anemia, cardiac disease, pregnancy, asthma, or bone marrow disorder. A prospective, randomized, double-blind, placebo-controlled crossover design was used comparing a 50:50 mixture of N(2)O/O(2) versus O(2). After recording baseline nonhatched 100mm visual analog scales (VAS) for pain and anxiety, subjects inhaled gas 1 for 120 seconds, followed by antecubital intravenous cannulation, discontinuance of gas and VAS rating of procedural pain and anxiety. After 15 minutes, the experiment was repeated with gas 2. Ten subjects would detect a 12mm difference in pain or anxiety with a standard deviation of 10 mm, an alpha error under 0.05 and a power over 80%. Differences between VAS were compared by matched 2-tailed t-test. Eleven subjects were enrolled. One withdrew because of dizziness while inhaling gas (N(2)O). The 10 remaining subjects reported significantly less pain (N(2)O/O(2) 14.5mm, SD 18; O(2) 34.3mm, SD 23.4; P < .01) and anxiety (N(2)O/O(2) - 7.9mm, SD 7.8; O(2) 6.0mm, SD 11.6; P < .02) when inhaling N(2)O/O(2) than when inhaling O(2) alone. N(2)O/O(2) provided significant pain and anxiety reductions during intravenous cannulation. Some patients may experience adverse perceptions while using N(2)O, limiting its utility. Further studies defining the role of N(2)O as an anxiolytic agent, efficacy in actual patients, and cost comparisons with intravenous conscious analgesia/sedation, are warranted.

U.S. Army MEDEVAC in the new millennium: a medical perspective.

The U.S. Army Aeromedical Evacuation community (MEDEVAC) possesses a long-standing tradition of excellence in the care and transportation of combat casualties. Recent developments in civilian air medical transport and quantitative review of MEDEVAC operations have identified potential areas for improvement, concentrating on enhanced flight medic standards, training, sustainment and medical oversight of the air ambulance system. These proposed changes are discussed in detail, from the perspective of current emergency medicine and aviation medicine standards of practice. If instituted, these changes would facilitate the emergence of a true air medical transport capability comparable with the civilian community standard.

U.S. Army air ambulance operations in El Paso, Texas: a descriptive study and system review.

OBJECTIVES: To analyze a high-volume military air ambulance unit and review the U.S. Army air medical transport system and Military Assistance to Safety and Traffic (MAST) program. METHODS: The setting was a remote medical system with numerous ground emergency medical services. All patients transported between January 1, 1996, and February 28, 1998, were included. Patients who were dead on scene or for whom records were unavailable were excluded. A retrospective review of transport and available inpatient records was conducted. RESULTS: Five hundred seventeen patients were transported during the study period; 461 patients met inclusion criteria (89%). Of these, 70% were classified as trauma; 30% possessed medical or other surgical diagnoses. Prehospital responses numbered 71.6%, while 28.4% were interhospital transfers. Missions averaged 23.4 minutes per flight, with no major aircraft mishaps. Prehospital utilization review showed appropriate use; 35% of interhospital trauma and 11% of interhospital nontrauma missions were staffed inadequately by these criteria. Time intervals, procedures, and program impact are discussed. CONCLUSION: This and similar units participating in the MAST program provide effective air transport in settings underserved by civilian programs. Quality and wartime readiness could be improved by centralized medical direction, treatment and transfer protocols, and enhanced training of medics. Further investigations of the clinical impact of advanced training and a two-medic aircrew model are warranted.

Military assistance to safety and traffic services in El Paso: a retrospective analysis.

This study was performed to evaluate the performance of military rotary air medical transport in the El Paso, Texas, region with regard to mortality. A retrospective review of transport and inpatient medical records was undertaken. All trauma patients air transported from January 1, 1996, to February 28, 1998, were included. Patients for whom records were unavailable were excluded. Mean time intervals for prehospital and interhospital transport were calculated. Injury severity and survival data were calculated using Revised Trauma Score, Injury Severity Score, and Trauma and Injury Severity Score (TRISS) methodology. Two hundred sixty-seven patients were eligible for analysis (83% of the total). TRISS analysis predicted 241 survivors; the actual number of survivors was 241 (mean = 0.98, z = 0.03) despite the fact that 6 individuals died who were predicted to live and 3 individuals lived who were predicted to die. We conclude that the actual mortality rate of those patients transported by military aeromedical lift equaled that predicted by TRISS methodology.

Adenosine conversion of supraventricular tachycardia associated with high-dose epinephrine therapy for cardiac arrest.

Adenosine has received wide acceptance as the drug of choice for initial treatment of supraventricular tachycardias (SVT), and as a diagnostic adjunct in hemodynamically stable, wide-complex tachycardias. This report describes the successful use of adenosine for the treatment of SVT occurring after successful initial resuscitation from ventricular fibrillation, in which a high dose of the epinephrine protocol was used.

Field deployment of automated external defibrillators to a Federal Fire Service unit under medical direction of a military emergency service.

Automated external defibrillators (AEDs) have been proven in numerous studies to decrease the time interval from cardiac arrest to defibrillation, thus improving the survival rate for victims of ventricular fibrillation and pulseless ventricular tachycardia, the most common causes of reversible sudden cardiac death. Recent Department of Defense initiatives have mandated increased participation of Federal Fire Service units in the conduct of prehospital emergency medical care on military and other federal installations. This report describes the development and deployment of an AED program for a fire department serving a U.S. military installation under the medical direction of that installation's medical treatment facility. This "first step" in the integration of Federal Fire Services into emergency medical care, as well as potential future military applications for AEDs, are discussed.

Intravenous adenosine as first-line prehospital management of narrow-complex tachycardias by EMS personnel without direct physician control.

This study was conducted to evaluate the safety and efficacy of intravenous adenosine therapy for prehospital treatment of narrow-complex tachycardias with a presumptive field diagnosis of paroxysmal supraventricular tachycardia (PSVT) by paramedics without direct physician control. A ten-month prospective case series was designed in an urban EMS system that has paramedics operating under standing orders before physician radio contact. All patients with PSVT field diagnosis were included. Diagnosis of PSVT was made by regular, narrow-complex tachycardia with a heart rate greater than 160 beats/min by field ECG. Interpretation was performed solely by paramedics; ECG transmission was not available. In hemodynamically stable patients, vagal maneuvers were followed by intravenous placement and administration of adenosine was recommended by the manufacturer. If three adenosine boluses failed to convert the arrhythmia, patients were monitored and transported, with electrical cardioversion available. Data collection included demographic, history, medications, vital signs, and EGG tracings. Of 14 included patients, 31 were correctly diagnosed with PSVT (75.6%), with mean ventricular rate of 205 beats/min (SD 7 beats/min); one had sinus tachycardia; nine had atrial fibrillation (AF) (22%). Of the 31 cases correctly diagnosed as PSVT, 28 converted to sinus rhythm after adenosine (90.3%). Of those converted, 16 required a single dose (57.1%), nine required one additional dose (32.1%), and three required two additional doses (10.8%). None reverted to PSVT after adenosine conversion during the study period (conversion to arrival at emergency department). No significant difference in length of asystolic pause or in outcome was detected between the true PSVT cases and the AF cases receiving adenosine.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of in vitro chemosensitivity of perioperative human ovarian malignancies by adenosine triphosphate chemosensitivity assay.

We report the in vitro chemosensitivity of primary and recurrent human ovarian tumor samples analyzed by adenosine triphosphate chemosensitivity assay. We defined sensitivity as a greater than or equal to 70% decrease in intracellular adenosine triphosphate versus control at 20% of the reported peak plasma concentration per agent tested. Twenty of 21 assays (95.24%) were completed successfully. Single-agent and combined dose-response patterns consisting of decreasing viability with increasing drug concentration were observed consistently. Thirteen primary tumors were assayed, with 15.4% sensitive to cisplatin, 7.7% sensitive to 4-hydroxycyclophosphamide and 53.8% sensitive to their combination. Seven recurrent tumors were assayed, with 14.3% sensitive to cisplatin, 28.6% sensitive to 5-fluorouracil, and 42.9% sensitive to their combination. Dose-response characteristics and in vitro sensitivity rates reported in this article are consistent with reports of patient response in the literature. We conclude that adenosine triphosphate chemosensitivity assay is an efficient and reliable instrument for the in vitro chemosensitivity assessment of human tumors and warrants further clinical investigation.

Comparative efficacy of short-term versus long-term cefoxitin prophylaxis against postoperative infection after radical hysterectomy: a prospective study.

We report the results of a randomized, double-blind comparison of short-term versus long-term cefoxitin prophylaxis against infections after radical abdominal hysterectomy with pelvic and para-aortic lymphadenectomy. Of 113 evaluable patients, 54 (47.8%) received short-term (three doses) and 59 (52.2%) long-term (12 doses) prophylaxis with intravenous cefoxitin (2 g per dose). No significant differences in demographics, preoperative risk factors, or clinical course were detected between the two groups; nor did we detect significant differences in the incidence of surgical-site-related infections (7.4 versus 5.1%, respectively, P = .61), postoperative urinary tract infection, or other febrile morbidity. We conclude that short-term and long-term cefoxitin prophylaxis are equally effective for the prevention of post-operative surgical-site-related infections after radical hysterectomy.