James R Mateer

Prehospital hypertonic saline/dextran infusion for post-traumatic hypotension. The U.S.A. Multicenter Trial.

The safety and efficacy of 7.5% sodium chloride in 6% dextran 70 (HSD) in posttraumatic hypotension was evaluated in Houston, Denver, and Milwaukee. Multicentered, blinded, prospective randomized studies were developed comparing 250 mL of HSD versus 250 mL of normal crystalloid solution administered before routine prehospital and emergency center resuscitation. During a 13-month period, 422 patients were enrolled, 211 of whom subsequently underwent operative procedures. Three hundred fifty-nine patients met criteria for efficacy analysis, 51% of whom were in the HSD group. Seventy-two per cent of all patients were victims of penetrating trauma. The mean injury severity score (19), Trauma Score plus Injury Severity Score (TRISS) probability of survival, revised trauma scores (5.9), age, ambulance times, preinfusion blood pressure, and etiology distribution were identical between groups. The total amount of fluid administered, white blood cell count, arterial blood gases, potassium, or bicarbonate also were identical between groups. The HSD group had an improved blood pressure (p = 0.024). Hematocrit, sodium chloride, and osmolality levels were significantly elevated in the Emergency Center. Although no difference in overall survival was demonstrated, the HSD group requiring surgery did have a better survival (p = 0.02), with some variance among centers. The HSD group had fewer complications that the standard treatment group (7 versus 24). A greater incidence of adult respiratory distress syndrome, renal failure, and coagulopathy occurred in the standard treatment group. No anaphylactoid nor Dextran-related coagulopathies occurred in the HSD group. Although this trial demonstrated trends supportive of HSD in hypotensive hemorrhagic shock patients requiring surgery, a larger sample size will be required to establish which subgroups of trauma patients might maximally benefit from the prehospital use of a small volume of hyperosmolar solution. This study demonstrates the safety of administering 250 mL 7.5% HDS to this group of patients.

Intraosseous infusion: An alternative route of pediatric intravascular access

Substantial difficulties can be encountered when establishing rapid intravascular access in critically ill children. The historic technique of tibial intraosseous infusion is presented as an alternate intravenous route in children less than 3 years old. Review of the literature reveals this technique to be a rapid, reliable method with an acceptably low complication rate. Substances absorbed through the marrow, flow rates, technical difficulties, and complications are discussed.

Model Curriculum for Physician Training in Emergency Ultrasonography

A model curriculum for the implementation and training of physicians in emergency medicine ultrasonography is described. Widespread use of limited bedside ultrasonography by emergency physicians will improve diagnostic accuracy and efficiency, increase the quality of care, and prove to be a cost-effective technique for the practice of emergency medicine.

Prehospital experience with defibrillation of coarse ventricular fibrillation: A ten-year review

Early defibrillation of patients with coarse ventricular fibrillation has been implicated as a predictor of survival in prehospital cardiac arrest. A retrospective study of our experience with prehospital defibrillation was conducted to define the relationship between rapid delivery of first countershock and survival, determine whether a relationship exists between the number of countershocks delivered and the save rate, and assist clinicians with general guidelines for termination of advanced life support efforts in the presence of ventricular fibrillation refractory to multiple defibrillation attempts. During the ten-year study period, adult, nontraumatic, nonpoisoned, witnessed arrests with an initial rhythm of coarse ventricular fibrillation were reviewed. Of 1,497 patients, 25% survived, 13% were paramedic-witnessed (PW) arrests, and 87% were non-paramedic-witnessed (NPW) arrests. The mean PW shock time, defined as time from arrest to first shock, was 1.6 +/- 3.7 minutes with a save rate of 37%. The mean NPW shock time was 10.2 +/- 5.1 minutes with a save rate of 23% (P less than or equal to .001). Thirty-two percent of PW arrests were converted to a spontaneous rhythm with pulses after the first countershock compared with 9% of NPW arrests (P less than or equal to .001). There was a dramatic decrease in PW arrests obtaining a perfusing rhythm after the first countershock attempt with each minute delay in electrical countershock up to three minutes; a plateau effect was evident after three minutes.(ABSTRACT TRUNCATED AT 250 WORDS)

Pre-hospital IAC-CPR versus standard CPR: Paramedic resuscitation of cardiac arrests

Recent studies evaluating interposed abdominal compression cardiopulmonary resuscitation (IAC-CPR) have demonstrated a significant increase in cardiac output, mean arterial pressure, and cerebral perfusion, as compared with standard CPR. A clinical evaluation of IAC-CPR effectiveness on resuscitation outcome has not been reported. A prospective randomized study comparing IAC-CRP with standard CPR for resuscitation of prehospital cardiopulmonary arrest was undertaken using the Milwaukee County Paramedic System. The patients were randomized following endotracheal intubation into IAC-CPR and standard CPR groups. Since October 1983, 291 patients have qualified for the study group. Of these, 146 patients had standard CPR, and 45 (31%) were successfully resuscitated. Of the 145 patients treated with IAC-CPR, 40 (28%) were successfully resuscitated. Chi-square analysis reveals no significant difference between these groups. To determine whether abdominal compression increases regurgitation, the frequency of emesis before and after intubation was analyzed. No significant difference was found between the IAC-CPR and standard CPR groups. Thus, IAC-CPR applied by paramedics in the field to patients following intubation does not improve cardiac resuscitation rates.

Bystander/first responder CPR: Ten years experience in a paramedic system

The effectiveness of bystander CPR recently has been challenged. We undertook a ten-year retrospective review of our prehospital experience with witnessed cardiorespiratory arrest to ascertain save rates in patients receiving and not receiving CPR before paramedic advanced life support (ALS). Traumatic and poisoning arrests and children less than 18 years old were excluded. A total of 1,905 patients presenting to a paramedic system from November 1, 1973, to October 31, 1983, were bystander-witnessed arrests and attempted paramedic resuscitations. Four hundred five paramedic-witnessed arrests were excluded. One hundred eighty-two of 1,248 (14.6%) who had CPR initiated before paramedic ALS arrival were saves, compared to 38 of 252 (15%) who had no CPR initiated until paramedic arrival (P = NS). A save was defined as a patient discharged from the hospital. The respective save rates for coarse ventricular fibrillation were 148 of 628 (23.6%) (CPR before paramedic arrival) vs 35 of 151 (CPR delayed until paramedic arrival) (23.2%); electromechanical dissociation (EMD), 11 of 209 (5.3%) vs 0 of 38; asystole, 19 of 401 (4.7%) vs 3 of 61 (4.9%); and ventricular tachycardia, four of ten (40%) vs 0 of two. In this prehospital system, bystander/first responder CPR was found not to improve hospital discharge rates except in patients with initially documented rhythm of EMD.

Decision making in prehospital sudden cardiac arrest

Many studies of prehospital resuscitation report on selected populations. We examined a series of 445 unselected nontraumatic cardiac arrests. Emergency cardiac care (ECC) was not initiated in 126 (28%). ECC was begun in 319 (78%), but was terminated in 132 (33%). Ninety-four (21%) were admitted to the hospital with palpable pulses and organized rhythm (successful resuscitation/save rate for patients presenting in ventricular fibrillation was 50%/25%. Multivariate regression analysis was used to identify the relative importance of significant variables in predicting survival, and the analysis identified the presence of ventricular fibrillation, short paramedic response times, and short paramedic treatment times.

EMT-defibrillation: The Wisconsin experience

The survival rate for patients with prehospital cardiac arrest has improved in some communities with early defibrillation by emergency medical technician-defibrillators (EMT-Ds). In rural areas, previous studies on survival with defibrillation by EMT-Ds have been variable. We conducted an EMT-D study to determine effectiveness in various prehospital settings. Sixty-four ambulance services from communities ranging in size from rural areas to city suburbs participated in our prospective study. EMTs were trained in rhythm recognition and the use of a manual defibrillator during a standardized 20-hour course. Over 18 months, data were collected locally for central analysis. Five hundred sixty-six patients with primary cardiac arrest were included in our study: 36 (6.4%) survived. Retrospective review revealed survival before EMT-D implementation to be 3.6% (P less than .02). Three hundred four patients (54%) had an initial rhythm of ventricular fibrillation, with 33 (11%) surviving. The survival rate for EMT-D-witnessed arrest with an initial rhythm of ventricular fibrillation was 42%. Patients with asystole were countershocked in our study; however, there were no survivors from this group. The neurologic status of survivors at time of hospital discharge was normal in 72%. The average response time, defined as time of emergency medical services activation to the time of EMT-D arrival, was 7.3 +/- 5.8 and 3.7 +/- 2.0 minutes for nonsurvivors and survivors, respectively (P less than .002). There were no survivors when the response time was more than eight minutes.(ABSTRACT TRUNCATED AT 250 WORDS)

Outcome analysis of a protocol including bedside endovaginal sonography in patients at risk for ectopic pregnancy.

STUDY OBJECTIVES To determine whether bedside endovaginal sonography (EVS) performed by emergency physicians reduces complications associated with ectopic pregnancy (EP) including missed EP and EP rupture. METHODS Our setting was an urban trauma center emergency department. We assembled a prospective convenience sample (n=314) with a historical EP control group (n=56) of women 18 years or older with a positive pregnancy test and any signs, symptoms, or risk factors for EP. Bedside EVS for all subjects and immediate quantitative serum human chorionic gonadotropin determination for patients with no definite intrauterine pregnancy by EVS. RESULTS Retrospective chart review identified 56 EP patients in the historical control group who had had no bedside EVS. Twenty-four of these patients (43%; 95% confidence interval [CI], 30% to 56%) were discharged from the ED, 12 of whom (50%; 95% CI, 30% to 70%) were later categorized as having ruptured EP. During the prospective study period, 40 patients were diagnosed as having EP; 11 (28%; 95% CI, 14% to 42%) were discharged from the ED (P=NS), and only 1 (9%; 95% CI, 0% to 26%) of the discharged patients was later determined to have a ruptured EP (P<.05). CONCLUSION An EP protocol incorporating bedside EVS performed by emergency physicians significantly reduced the incidence of discharged patients with subsequent EP rupture, compared with historical controls.

Prospective evaluation of abdominal sonography for the diagnosis of bowel obstruction.

OBJECTIVE The authors determined the utility of sonography compared with plain x-rays in the diagnosis of bowel obstruction. In a contemporaneous group of patients, they compared the cost of operative versus nonoperative management of small bowel obstruction. SUMMARY BACKGROUND DATA Nonoperative treatment of simple bowel obstruction usually succeeds. However, because of the difficulty in assured diagnosis and the possibility of strangulation or other complication, exploration of suspected bowel obstruction is recommended. Most of these explorations could be avoided if diagnostic accuracy were better, yielding a desirable decrease in the overall cost of managing bowel obstruction. METHODS Fifty patients whose clinical or plain x-ray findings suggested bowel obstruction underwent prospective evaluation by abdominal sonography and by flat and upright abdominal x-rays. Presence or absence of bowel obstruction was determined at laparotomy and by clinical evolution of the abdominal episode. Direct costs of care were determined from the hospital and physician bills of 54 patients treated contemporaneously with the sonography study. RESULTS Sonography demonstrated bowel obstruction by showing fluid-filled dilated bowel loops proximal to collapsed bowel in 22 patients with one false-positive and three false-negative examinations. X-rays demonstrated bowel obstruction in 32 patients with nine false-positive and one false-negative examination. Cost data showed that operative treatment of simple bowel obstruction increased costs nearly eightfold. CONCLUSIONS Sonography is as sensitive but more specific than plain x-rays in the diagnosis of bowel obstruction. Management based on sonographic findings has the potential to reduce costs of surgical care.