Change in survival from out-of-hospital cardiac arrest and its effect on coronary heart disease mortality, Minneapolis-St. Paul. The Minnesota Heart Survey.

Emergency medical services with advanced life support systems were implemented in the Minneapolis-St. Paul, Minnesota, area in the mid-1970s. To assess the impact of emergency medical services on coronary heart disease mortality, the authors reviewed ambulance records and hospital emergency room logs for possible out-of-hospital cardiac arrest cases in the period 1972-1982. Potential cases, and their survival to discharge, were validated by hospital record review and were checked against Minnesota death certificates for the year of cardiac arrest and the year following cardiac arrest. Age-adjusted rates of survival to 1 year after cardiac arrest (per 100,000 population) for survivors of out-of-hospital cardiac arrest aged 30-74 years increased significantly from 1972 to 1982 for men (1.8 vs. 11.7; p less than 0.00001) and for women (0.5 vs. 3.5; p less than 0.01). Coronary heart disease mortality rates declined in that period by 34.9% for men (from 527.5 per 100,000 to 343.3 per 100,000) and by 41.7% for women (from 168.6 per 100,000 to 98.3 per 100,000). The authors estimate that improved survival from out-of-hospital cardiac arrest contributed 5.4% (9.9 of 184.2) of the mortality decline for men and 4.3% (3.0 of 70.3) of the decline for women. This was a significant contribution to the decline in coronary heart disease mortality, but it explains only a small part of it.

Analyses of the relationship between blood alcohol and nasal breath alcohol concentrations: implications for assessment of trauma cases.

To prevent serious complications and facilitate efficient and effective management of patients admitted to the emergency department or intensive care settings, it is extremely important to differentiate, quickly, between elevated concentrations of alcohol in the blood and compromised neurological status due to brain injury or other pathology. This research analyzed the relationship between blood alcohol concentrations (BACs) estimated from venous blood samples and those estimated from breath samples that were obtained using the Alco-Sensor III device with an attached tube for passive nasal breath sampling. Blood and breath samples, as well as brief medical histories and demographic and environmental data, were obtained and recorded for 35 adult trauma patients admitted to two major urban emergency departments. Passively expired nasal breath provided an excellent estimate of BAC measured from venous blood (range, 0 to 0.32) as evidenced in the extremely high regression coefficient (r = 0.99; slope = 1.22; p less than 0.0001). BAC assessment and monitoring, through the application of passive nasal breath sampling, provides a means of rapidly estimating BAC, and thus can facilitate diagnosis and the initiation of appropriate management and treatment.

Cardiac arrest under age 40: etiology and prognosis.

Between January 1979 and December 1982, 84 patients between the ages of 1 and 39 years presented to the emergency department in a state of cardiac arrest. There were 58 male patients (69%) and 26 female patients (31%) in the group. Presenting rhythms were ventricular fibrillation (37%), asystole (37%), idioventricular rhythm (14%), heart block (4%), bradycardia (4%), ventricular tachycardia (3%), and electromechanical dissociation (3%). Thirty-two percent had bystander CPR. Of 21 patients initially resuscitated (25%), only four (5%) survived to discharge from the hospital. All survivors were neurologically intact. Seventy-five of the 80 patients who died (90%) underwent autopsy. Cause of death in the five remaining patients was inferred from clinical history. Etiologies of the cardiac arrests were the following: toxic exposure or ingestion (26%), atherosclerotic heart disease (23%), undetermined (11%), pulmonary embolism (6%), hemorrhage (6%), epilepsy (2%), cardiomyopathy (7%), myocarditis (2%), pneumonia (4%), and one case each of airway obstruction, asthma, peptic disease, and septic shock. Diverse etiologies should lead to a diagnostic search for reversible conditions in young patients. The prognosis for hospital discharge is poorer in the young population than is reported in our overall cardiac arrest population; however, numbers of neurologically intact survivors are similar in the young and the overall cardiac arrest population.

MAST usage in cardiopulmonary resuscitation.

The medical antishock trouser (MAST) has been advocated as potentially beneficial in the resuscitation of patients in cardiac arrest. Currently available data indicate that the MAST will increase the blood pressure generated by external cardiopulmonary resuscitation. In addition, there may be an increased survival of patients found in cardiac arrest with an initial cardiac rhythm of pulseless idioventricular rhythm when the MAST is used. The physiologic parameters affected by the MAST may be similar to those caused by vasopressor agents in animal studies and implicated in increased survival rates. The clinical implications of these data and their relation to future investigations are discussed.

Effect of pneumatic trousers on intracranial pressure in hypovolemic dogs with an intracranial mass.

Thirty-six dogs under chloralose anesthesia were studied in groups of six. Arterial pressure (BP), central venous pressure (CVP), intracranial pressure (ICP), and arterial blood gases were monitored. The group underwent: 1) anesthesia only; 2) phlebotomy (P) (40% of blood volume) and reinfusion (RI) of half the shed blood plus Ringer's lactate solution; 3) P followed by pneumatic trousers (PT), and then RI; 4) inflation of an epidural 2-cc Foley catheter (EFC); 5) P followed by EFC and then RI; and 6) P followed by EFC and then by PT and RI. Group 1 was stable. In Group 2, P lowered BP (49 torr systolic +/- 6 SEM), CVP, and ICP. RI restored these. In Group 3, the PT improved BP (P less than .05) without increasing ICP. In Group 4, EFC increased ICP (P less than .05) to 15 +/- 4 torr. In Groups 5 and 6, ICP was not significantly increased by EFC or PT and RI.

Augmentation of systolic blood pressure during external cardiac compression by use of the MAST suit.

External cardiac compression has been shown to circulate blood effectively, but the systolic pressures obtained are less than normal cardiac functioning. This study was undertaken to determine whether applying the military anti-shock trouser (MAST) suit resulted in improving systolic blood pressure while using external cardiac compression during cardiac resuscitation. Individuals admitted to the emergency department in cardiac arrest had external cardiac massage applied at a constant rate and force. Intra-arterial blood pressure monitoring was established and baseline systolic blood pressure obtained. In eight patients, the average increase in systolic blood pressure utilizing the MAST suit was 15 mm Hg. The implications of these findings, as well as other means to increase cardiac output in the cardiac arrest patient, are discussed. These findings will be related to both prehospital and emergency department care of patients in cardiac arrest.

Intravenous glucagon in the management of esophageal food obstruction.

The use of intravenous glucagon in patients with obstructing esophageal food impaction of at least 24-hours duration has recently been described. Two cases of acute esophageal obstruction were relieved within ten minutes by intravenous infusion of 1 mg of glucagon. Esophagram performed both before and after glucagon administration confirmed the original obstruction and the passage of the food bolus. Therapy for bolus obstruction of the esophagus has classically included proteolytic enzyme digestion, as well as esophagoscopy with manual extraction. Each entails risk of esophageal perforation and mediastinitis. Also, the dose of proteolytic enzymes, such as papain, may take several hours to administer while endoscopic examination is generally not feasible as an outpatient emergency procedure. Intravenous glucagon can dissolve food other than meat and has the further advantage of safety in the patient in which anticholinergics, another occasionally employed therapy, are contraindicated. A protocol for management of these patients is included.

Clinical assessment of patients undergoing CPR in the emergency department.

A problem frequently encountered in the emergency department is assessing the effectiveness of cardiopulmonary resuscitation (CPR), particularly when it is continued over a period of time. To evaluate the effectiveness of CPR in our emergency department we use a mechanical cardiopulmonary resuscitator (Michigan Instruments, Thumper) together with early invasive monitoring of pulse and blood pressure. This also allows for frequent monitoring of blood gases. Three patients are presented who underwent longterm CPR (ie, longer than one hour), and invasive monitoring. Results indicate that better management of the clinical status of patients undergoing prolonged resuscitation can be obtained by using continuous blood pressure and pulse monitoring, and frequent blood gas analysis. In addition, when frequent arrhythmias are taking place, this system allows for better determination of appropriate procedures and medications.