David W Olson

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)

Should the elderly be resuscitated following out-of-hospital cardiac arrest?

PURPOSE Elderly and younger patients who were successfully resuscitated and hospitalized following out-of-hospital cardiac arrest were studied to determine if there was a significant difference in hospital course and long-term survival between the two groups. PATIENTS AND METHODS The study consisted of 214 consecutive patients, divided into two age groups: elderly (more than 70 years, n = 112) and younger (less than 70 years, n = 102). Hospital charts and paramedic run data were retrospectively reviewed for each patient and findings were compared between the two age groups. RESULTS Prior to cardiac arrest, 47 of 112 (42 percent) elderly patients had a history of heart failure, compared with 19 of 102 (18 percent) younger patients, and were more commonly taking digitalis (51 percent versus 29 percent) and diuretics (47 percent versus 26 percent). Younger patients, however, more often had an acute myocardial infarction at the time of the cardiac arrest (33 percent versus 16 percent). At the time of cardiac arrest, 83 percent of younger patients demonstrated ventricular fibrillation, compared with 71 percent of the elderly. In contrast, electromechanical dissociation was five times more common in the elderly patients. Although hospital deaths were more common in the elderly (71 percent versus 53 percent), the length of hospitalization and stay in intensive care units were not significantly different between the age groups. The number of neurologic deaths was similar in both age groups, as were residual neurologic impairments. Only five elderly patients and six younger patients required placement in extended-care facilities. Calculated long-term survival curves demonstrated similar survival in both age groups, with approximately 65 percent of hospital survivors alive at 24 months after hospital discharge. CONCLUSION Resuscitation of elderly patients in whom out-of-hospital cardiac arrest occurs is reasonable and appropriate, according to the findings of this study. Even though elderly patients are more likely than younger patients to die during hospitalization, the hospital stay of the elderly is not longer, the elderly do not have more residual neurologic impairments, and survival after hospital discharge is similar to that in younger patients.

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)

Prehospital External Cardiac Pacing: A Prospective, Controlled Clinical Trial

This prehospital prospective, controlled study was conducted to determine if prehospital cardiac pacing affects survival. The study involved 239 patients, 226 pulseless, nonbreathing patients (rhythms of asystole and electromechanical dissociation with heart rates less than 70) and 13 patients with hemodynamically significant bradycardia (heart rate less than 60; blood pressure less than 90 mm Hg; not responding to atropine). Patients were assigned to treatment or control groups on an every-other-day basis. One hundred three patients were treated with an external cardiac pacing device; 22 (21.4%) were resuscitated (arrival at admitting hospital with pulse and blood pressure) and seven (6.8%) were saved (survival to hospital discharge). One hundred thirty-six patients were not paced and served as controls; 28 (20.6%) were resuscitated (P = .90) and six (4.4%) were saved (P = .71). Analysis of pacing times showed increased resuscitation in patients paced early. All surviving paced patients were paced in 17 minutes or less. Analysis of rhythm subgroups showed no significant difference in the resuscitation or survival rates of paced and control groups for primary asystole, primary electromechanical dissociation, and secondary asystole and electromechanical dissociation occurring after countershock treatment of ventricular fibrillation when compared respectively. However, among patients with hypotensive bradycardia, six of six paced patients were resuscitated and five were saved, while only two of seven controls were resuscitated (P = .01) and one was saved (P = .01). Interpretation of the bradycardic patient data is limited by inequalities noted between control and treatment groups with regard to the administration of isoproterenol.(ABSTRACT TRUNCATED AT 250 WORDS)

Prehospital bicarbonate use in cardiac arrest: A 3-year experience

The American Heart Association no longer recommends the routine use of sodium bicarbonate in cardiac arrests. Reasons cited include the lack of documented effect on clinical outcome and potential adverse effects of metabolic alkalosis and hypernatremia. We reviewed 36 months of experience with 619 nontrauma adult, prehospital cardiac arrest patients to identify 273 successful resuscitations who had emergency department blood gases and electrolytes performed. Determination of complications associated with prehospital intravenous sodium bicarbonate and its impact on survival in resuscitated patients was undertaken. Fifty-eight patients did not receive sodium bicarbonate (NO HCO3 group) and had short cardiopulmonary resuscitation (CPR) times (7.4 +/- 5.5 minutes). Two hundred fifteen patients did receive sodium bicarbonate (HCO3 group) and had significantly longer CPR times (23.3 +/- 13.5 minutes, P less than or equal to .001). Both groups demonstrated routine early chest compression and hyperventilation as evidenced by no significant difference in paramedic response time or rate of intubations. Initial emergency department blood gas results of both groups were not significantly different. No patients in the NO HCO3 group had hypernatremia (sodium [Na]+ greater than 150), whereas four patients (2%) in the HCO3 group were hypernatremic. Eight patients (14%) in the NO HCO3 group and 37 patients (17%) in the HCO3 group were alkalotic with pH values greater than 7.49 (P = NS). Six patients (10%) of the NO HCO3 group and 24 patients (11%) of the HCO3 group had a metabolic component to the alkalosis as defined by a positive base excess value (P = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

A randomized comparison study of bretylium tosylate and lidocaine in resuscitation of patients from out-of-hospital ventricular fibrillation in a paramedic system

A prospective, randomized study using either bretylium tosylate (BT) or lidocaine (L) as the first-line antiarrhythmic for patients in refractory ventricular fibrillation was conducted using the Milwaukee County Paramedic System. If the patient did not respond to the initial American Heart Association protocol, BT (10 to 30 mg/kg total) or L (2 to 3 mg/kg total) was given randomly as the first antiarrhythmic. If the patient failed to convert, the alternate antiarrhythmic was given. In the L group, 81% (39/48) of the patients obtained an organized electrical rhythm and 56% (27/48) converted to a rhythm with a pulse. The resuscitation rate (admission to an emergency department with pulse) was 23% (11/48), and the save rate was 10.4% (5/48). In the BT group, 74% (32/43) obtained an organized electrical rhythm, 35% (15/43) were converted, 23% (10/43) were resuscitated, and 5% (2/43) were saved. The only significant difference in outcome was that L converted patients better than did BT (P less than .05). Of the 24 patients known to be on digitalis preparations prior to arrest, 41% (5/12) in the L group were resuscitated and 16% (2/12) were resuscitated in the BT group. Data were analyzed for witnessed arrest outcome and for patients given multiple antiarrhythmics.

Randomized study of epinephrine versus methoxamine in prehospital ventricular fibrillation

Experimental data suggest that a pure alpha-agonist, such as methoxamine, may improve the outcome of patients in ventricular fibrillation. A double-blind, randomized, prospective study was conducted in a paramedic system comparing the use of methoxamine with epinephrine in enhancing conversion of ventricular fibrillation while otherwise following American Heart Association protocols. One hundred two patients in ventricular fibrillation not responding to initial defibrillations with a pulsatile rhythm were randomized into one of two groups, each containing 51 patients. Equipressor doses of epinephrine (0.5 mg) and methoxamine (5 mg) were given intravenously and repeated according to American Heart Association guidelines. The mean age, sex ratio, and mean paramedic response times were comparable for the two groups. The mean time at scene until conversion was 22 +/- 10 minutes for methoxamine and 17 +/- 7 minutes for epinephrine (P = NS). The methoxamine group received 3.1 +/- 1.4 doses as compared with 2.8 +/- 1.3 doses for the epinephrine group (P = NS). Conversion rate, defined as the percentage of patients who developed a pulse during resuscitation, was 27.5% for the methoxamine group and 49.0% for the epinephrine group (P less than or equal to .03). Successful resuscitation, defined as the conveyance of a patient to an emergency department with a pulse and rhythm, was 17.7% for the methoxamine group and 39.2% for the epinephrine group (P less than or equal to .02). Save rate, defined as the percentage of patients discharged alive after hospitalization, was 7.8% for the methoxamine group and 19.6% for the epinephrine group (P less than or equal to .07).(ABSTRACT TRUNCATED AT 250 WORDS)

Emergency airway management in hanging victims

STUDY OBJECTIVE To determine the incidence, demographics, clinical indicators of survival, and frequency of cervical-spine fractures to define appropriate emergency airway management in hanging victims. DESIGN Medical examiner records, paramedic reports, and emergency department and hospital medical records were reviewed retrospectively for the period January 1, 1978, to January 1, 1990. SETTING Urban paramedic system with nine receiving hospitals. PARTICIPANTS A total of 160,724 medical examiner and paramedic records were reviewed to identify a total study population of 306 hanging victims. One hundred eighty-two victims (59%) were found dead at the scene, and the emergency medical system was not notified. An additional 57 (19%) were seen by paramedics and declared dead at the scene. Sixty-seven (22%) were treated and transported to nine receiving EDs; 39 of these 67 received oral or nasal endotracheal intubation. RESULTS The incidence of hanging was 0.19% of all medical examiner cases and paramedic runs during the 12-year study. Those hanging victims who survived to receive paramedic transport and treatment by physicians were typically male and attempted suicidal hanging in a public place (most frequently jail) with available bedding or clothes. No hanging victim treated and transported by paramedics had documentation of cervical-spine or spinal cord injury. CONCLUSION In nonjudicial hanging victims seen by paramedics and transported to an ED, cervical-spine injury is rare. Cerebral hypoxia rather than spinal cord injury is the probable cause of death and should be the primary concern in treatment of this patient population. Following external stabilization of the neck, nasal or oral endotracheal intubation is appropriate emergency airway management in hanging victims.

THE EFFECT OF BYSTANDER CPR ON NEUROLOGIC OUTCOME IN SURVIVORS OF PREHOSPITAL CARDIAC ARRESTS

The efficacy of CPR has been questioned. A major criticism is that neurologic outcomes have not been adequately studied. For a 26-month period, 138 patients from six major receiving hospitals were discharged alive following prehospital cardiac arrests. For 65/138 (47.1%) patients, either the patient or a direct family member was contacted for information concerning neurologic outcome. For 63/138 (45.7%) patients, contact with patient or family was unsuccessful, consequently neurologic outcome at time of discharge was obtained from the medical record. For 10/138 (7.2%) patients, no data on neurologic outcome was obtainable. Neurologic outcome was rated by a 5-point Cerebral Performance Categories Scale (CPC); (1) Minimal Disability; (2) Moderate; (3) Severe; (4) Vegetative; and (5) Brain Dead. The bystander/first responder CPR group had 55.1% CPC-1; 24.4% CPC-2; 16.7% CPC-3; and 3.8% CPC-4 outcomes. The bystander/first responder NO CPR group had 58.0% CPC-1; 18.0% CPC-2; 16.0% CPC-3; and 8.0% CPC-4 outcomes. There was no significant difference at any CPC level (P not significant). Furthermore, there was no statistical difference between either group when compared for age, response time, resuscitation time, witnessing of arrest or distribution of presenting rhythms. In conclusion, no significant effect in neurologic outcome among saved cardiac arrest victims was found between bystander/first responder CPR and bystander/first responder NO CPR groups in the paramedic program studied.