Digoxin levels in prehospital sudden-death syndrome.

Digitalis toxicity is common and has been associated with ventricular dysrhythmias. Digoxin levels in patients who suffer prehospital sudden death have never been studied. This study measured digoxin levels in a population of sudden-death patients. During the 15-week study period, 252 patients in cardiac arrest were seen by an urban paramedic system. During daytime hours, paramedics were requested to obtain a blood sample from sudden-death patients; the samples were subsequently analyzed for digoxin by means of radioimmunoassay. Thirty-nine patients had measured digoxin levels drawn; 28 (71.8%) were in the therapeutic range (0.5-2.1 ng/mL), and four (10.2%) were in the toxic range (greater than 2.1 ng/mL). The patients with toxic dogoxin levels and those with nontoxic levels had similar resuscitation rates (50.0% vs. 34.3%, P = NS), but none were found in ventricular fibrillation. Emergency medical services personnel should consider digoxin toxicity as a potential etiology of arrest.

Successful resuscitation using transcutaneous cardiac pacing.

Reported here is the case of a patient suffering from hemodynamically significant bradycardia in which the use of transcutaneous cardiac pacing resulted in successful resuscitation, obviating the need for invasive pacing. During pacing, intra-arterial recordings of blood pressure demonstrated higher pulse pressures for paced beats than for the patient's own escape beats. Recent data regarding the use of non-invasive transcutaneous cardiac pacing is also reviewed.

Prehospital cardiac arrest--a critical analysis of factors affecting survival.

During a 10-year period, 5631 cardiac arrests were treated in our paramedic system. In all, 4216 resuscitations were attempted, of which 533 (12.6%) resulted in saves, defined as hospital discharges. Patients presenting with an initial rhythm of coarse ventricular fibrillation or ventricular tachycardia were found to have significantly increased save rates in comparison to those presenting with an initial arrest rhythm of asystole/fine ventricular fibrillation or electromechanical dissociation (P less than or equal to 0.01). When controlling for witnessed arrest, 303 of 1905 (15.9%) of all witnessed arrests were saves vs. 230 of 2311 (10%) of unwitnessed arrests (P less than or equal to 0.01). Witnessed bystander/first responder external cardiac compression- cardiopulmonary resuscitation (ECC-CPR) was found not to influence save rate. One hundred eighty-one of 1248 bystander/first responder witnessed arrests (14.5%) who had external ECC-CPR initiated before paramedic advanced life support arrival were saves, compared with 38 of 252 (15.1%) who had no ECC-CPR initiated until paramedic arrival; this was not statistically significant. Advanced life support response times in saved patients with witnessed cardiac arrests were analyzed. Ninety-five percent of all saves had a response time of less than 10 min. We conclude that, when evaluating the effectiveness of CPR, the variables of witnessing of arrest, presenting arrest rhythm, and respective response times must be controlled or analyzed.

Electromechanical dissociation: six years prehospital experience.

Electromechanical dissociation (EMD) is the presenting rhythm in approximately 17% of all prehospital cardiorespiratory arrests. Yet, we know comparatively little about the demographic profile of these patients. The purpose of this study was to review historical and resuscitative parameters to help create a demographic profile. For a 6-year period of time from January 1st, 1980 to December 31st, 1985, 503 adult patients presented to a prehospital system in non-traumatic, nonpoisoned, cardiorespiratory arrest with an initial rhythm of electromechanical dissociation. The overall average response time was 6.1 +/- 3.2 min. Sixty percent of the patients were witnessed arrests and 65% had bystander initiated CPR. Forty-six percent of the patients had a cardiac history: myocardial infarction 13%, CHF 11% and other 21%. Other pertinent past medical history included diabetes 15%, COPD 10% and seizures 3%. The average age was 69.8 +/- 13.7 years. Fifty-seven percent were male. Forty-three percent were on cardiac medication including: digoxin, 24%; nitroglycerin, 12%; potassium supplements, 9%; propranolol, 8%; isordil, 6%; quinidine, 3%; nitropaste, 3%; and other cardiac medications, 15%. One hundred forty-eight (29%) patients developed a pulse at some time during resuscitative efforts, of these 17 (3.4%) patients responded with a pulse immediately after intubation. The mean time of resuscitation to sustaining pulse was 20 +/- 11 min and the mean resuscitation time to sustaining pressure was 22 +/- 11 min. Nineteen percent were successfully resuscitated, defined as a conveyance of a patient with a pulse and a rhythm to an emergency department. Four point four percent were saved, defined as a patient discharged alive from the hospital. Approximately 53% of the successfully resuscitated patients and 45% of the save patients were determined to have a probable respiratory event as the primary etiology of their arrest. This study attempts to provide some insight into the demographic profile of the patients in EMD.

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.

Interventions in the therapy of electromechanical dissociation.

Electromechanical dissociation (EMD) is a major arrest rhythm for which there is often inadequate treatment. The purpose of this study was to evaluate the different pharmacological and non-pharmacological interventions considered in the treatment of EMD. During the 6-year period, January 1st, 1980 to December 31st, 1985, 503 evaluable adult patients presented in a non-traumatic, non-poisoning cardiopulmonary arrest with the initial rhythm of EMD. One hundred nineteen patients obtained a pulse during resuscitation efforts following drug administration. The average time to obtaining pulses after the last drug administration was 1.97 +/- 2.21 min. The following drugs were last administered prior to transient pulses: bicarbonate, 31/119 (26%); epinephrine, 26/119 (22%); atropine, 26/119 (22%); dopamine, 13/119 (11%); calcium, 11/119 (9%); isoproterenol, 7/119 (6%); other drugs, 5/119 (4%). Ninety-five percent of the successful resuscitations received eight or less drug interventions and all saves received three or less drug interventions. Two hundred twenty-four patients (44.5%) had 288 non-pharmacological interventions. Twenty-three patients developed a pulse after intervention in the following distribution: MAST suit (N = 9), pericardiocentesis (N = 6), fluid challenge (N = 5), needle thoracostomy (N = 1), and intervention combinations (N = 2). The time interval between intervention and the onset of pulse was as follows: MAST suit, 4 +/- 2.8 min; pericardiocentesis, 3.7 +/- 3.6 min; fluid challenge, 4.8 +/- 4.1 min; needle thoracostomy, 6 min. The overall save rate for intervention patients was 0.9% whereas for those not having intervention it was 7.2% (P less than or equal to 0.0003).(ABSTRACT TRUNCATED AT 250 WORDS)

Defining electromechanical dissociation: morphologic presentation.

Electromechanical dissociation (EMD) is inconsistently defined in the literature. Our definition is the presence of discernible electrical complexes (excluding ventricular tachycardia and ventricular fibrillation) and the absence of palpable pulses. It has been noted that EMD may present with a variety of morphological complexes. It was the purpose of this study to categorize the electrical morphologic characteristics of patients presenting in EMD and to correlate morphology with patient outcome and response to therapy. From the 6-year period, January 1st, 1980 to December 31st, 1985, 503 evaluable adult patients presented to an urban paramedic system in non-traumatic, non-poisoned, cardiorespiratory arrest and were determined to be in EMD. The rhythm strips obtained from paramedics on all patients were retrospectively reviewed and were arbitrarily categorized in the following manner: Group 1, normal QRS width, isoelectric ST and normal appearing T-waves; Group 2A, atrial activity, widened QRS width (greater than or equal to 0.12 ms) or abnormal ST and/or T-waves (ST depression, elevation, slurring or T-wave inversion); Group 2B, same as Group 2A but without atrial activity; Group 3, essentially monophasic, slurred RST complexes. The respective initial distribution was Group 1, 147 (29%); Group 2A, 248 (49%); Group 2B, 60 (12%); Group 3, 48 (10%). The relative frequency of morphologies preceding the attainment of a pulse was as follows: Group 1, 30 (24%); Group 2A, 82 (65%); Group 2B, 8 (6%); Group 3, 6 (5%) (P less than or equal to 0.01 with no significant difference between Group 2B and 3).(ABSTRACT TRUNCATED AT 250 WORDS)

Electrocardiographic characteristics in EMD.

Little has been written concerning the initial electrocardiographic (EKG) characteristics and/or changes which occur as the result of treatment in the electromechanical dissociation (EMD) patient. The purpose of this retrospective study was to determine predictive indicators of successful resuscitation in EMD by evaluating various EKG parameters. During 72 months, ending December 31st, 1985, there were 503 non-poisoned, prehospital adult cardiac arrest patients whose initial rhythm was EMD. All patients had their initial prehospital EKG rhythm strip evaluated for rhythm type, rate, the presence of P waves, QT interval and QRS interval. In successfully resuscitated patients, the prehospital initial rhythm analysis and the rhythm analysis on emergency department presentation were compared. Successfully resuscitated patients presenting with EMD had significantly faster initial rates, higher incidences of P waves and average QRS and QT intervals shorter than patients not responding to therapy. Furthermore, successfully resuscitated patients had significantly increased heart rates, developed new onset of P waves, and shortened QT intervals in response to treatment. Successfully resuscitated and save patients had average initial and final QRS complex lengths within normal limits. Organized atrial activity on the initial EKG was also correlated with successful resuscitation. No patient with an initial EKG rhythm of second or third degree AV block survived to hospital discharge. No patient who presented to the emergency department with atrial fibrillation survived to hospital discharge. Similarly, supraventricular tachycaydia following resuscitative efforts appeared to be associated with a negative outcome. Rate normalization following treatment was correlated with save rate. Wide complex rhythms without atrial activity were most highly associated with unsuccessful resuscitation. We believe these observed electrocardiographic characteristics and/or changes in response to treatment may have predictive value in evaluating patients with EMD.

A hazardous material episode: sulfur trioxide.

Twelve people working next to a chemical plant noted an emission of 2 h. Nine patients complained of a variety of symptoms, including 3 who had pleuritic chest pain, 2 with chest tightness, 2 with vague chest discomfort, 3 with eye irritation, 2 with dizziness, 1 with light-headedness, 1 with cough and 1 with an acidic taste in the mouth associated with nasal irritation. Pulmonary function was 100% of predicted in 5; 77.4, 85.7, 95.7, and 96.7% of predicted in the other 4. Three of the 4 with initial decreased FEV1's (forced expiratory volume in 1 sec) improved. At follow-up, 1 had burning sensation of the tongue and mouth; a second noted burning sensation of his throat, tip of his tongue, and nostrils; and a third had superficial exfoliative-type lesions at the junction of her forehead and scalp. Two complained of continuous pleuritic chest pain. Sulfur trioxide exposure caused self-limited irritant effects.

Continuous pulse oximetry during emergency endotracheal intubation.

STUDY OBJECTIVE: To determine whether continuous pulse oximetry improves the recognition and management of hypoxemia during emergency endotracheal intubation. DESIGN: A prospective, serial 14-month study. SETTING: Emergency department, Level I trauma center. TYPE OF PARTICIPANTS: All adult patients requiring emergency intubation for whom data collection would not compromise patient care. INTERVENTIONS: All samples were obtained from a finger site at a five-second sampling interval and stored in computer memory. Patients were intubated by the nasotracheal or orotracheal route. MEASUREMENTS AND MAIN RESULTS: One hundred ninety-one consecutive adult patients qualified for the study and 211 intubation attempts were analyzed. Hypoxemia (O2 saturation, less than 90%) occurred during an intubation attempt in 30 of 111 nonmonitored versus 15 of 100 monitored attempts (P < .05), and the duration of severe hypoxemia (O2 saturation, less than 85%) was significantly greater for nonmonitored attempts (P < .05). CONCLUSION: Continuous pulse oximetry monitoring reduces the frequency and duration of hypoxemia associated with emergency intubation attempts.

Lack of effectiveness of calcium chloride in refractory asystole.

The effectiveness of calcium chloride in asystole has been challenged; retrospective studies have not supported its use. We conducted a prospective, randomized, blinded study comparing the effectiveness of calcium chloride with saline in the prehospital paramedic setting. Seventy-three patients who had received epinephrine, bicarbonate, and atropine and were in refractory asystole were included in the study, which was conducted from October 1982 to October 1983. Traumatic and pediatric arrests were excluded. The successful resuscitation rate was three of 39 in the calcium group versus one of 34 in the saline group (P less than .37). A successful resuscitation was defined as the conveyance of a patient with a pulse and a rhythm to an emergency department. Groups were analyzed for sex, age, and witnessed arrests. There was no statistically significant difference between the groups. No patient who was resuscitated successfully in the field was discharged from the hospital alive. We conclude that calcium chloride is not of value in resuscitating patients from refractory asystole in the prehospital cardiac arrest setting.

The effectiveness of calcium chloride in refractory electromechanical dissociation.

The effectiveness of calcium in electromechanical dissociation (EMD) has been challenged. Retrospective studies have been contradictory. To determine its effectiveness a prospective, randomized, blinded study comparing calcium chloride and saline in refractory EMD was carried out in the pre-hospital setting from October 1982 to October 1983. Only patients who had received epinephrine and bicarbonate and were refractory were entered in the study. All trauma and pediatric arrests were excluded. Ninety patients presented in refractory EMD. Overall, eight of 48 who received calcium were resuscitated successfully in the field; two of 42 who received saline were resuscitated successfully (P less than .07). A successful resuscitation was defined as the conveyance of a patient with a pulse and a rhythm to an emergency department. Patients were analyzed for age, sex, and witnessing of arrest. There was no statistical difference in demographic data. When the group of EMD patients was broken down into subgroups based on the width of QRS, it was noted that patients with a QRS width less than 0.12 did not respond to calcium, whereas the successfully resuscitated in the group with widened QRS or ischemic changes (N = 70) was eight of 39, compared with one of 31 not receiving calcium (P less than .028). Only one patient who was resuscitated successfully was discharged from the hospital alive. Calcium has been shown to be effective in the cardiac resuscitation of patients in refractory EMD. There may be a subset of patients with widened QRS complexes or ischemic changes who will benefit to a greater extent from the use of calcium chloride.

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.

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)

50% dextrose: antidote or toxin?

The empiric administration of 50% dextrose to all patients presenting to the ED with altered mental status is a standard of care predicated on the assumption that glucose administration is harmless to non-hypoglycemic patients. Considerable evidence now disputes this assumption. Glucose administration before complete cerebral ischemia in experimental animals worsens neurologic and histologic outcome. Administration of glucose during severe incomplete ischemia has a similar detrimental effect. The translation of these experimental findings into clinical practice has been slow, perhaps hindered by the frequent use of rodent models and large bolus doses of glucose. However, evidence is now provided by primate and human studies and by experimental designs using clinically relevant doses of glucose. These clinical and experimental findings in conjunction with the wide availability of a rapid bedside screen for hypoglycemia provide the rationale for an alteration in the standard of care. The empiric administration of glucose should be avoided in patients at risk for cerebral ischemia, such as those with acute stroke, impending cardiac arrest, or severe hypotension or receiving CPR. A bedside fingerstick blood glucose estimation should be performed immediately on all patients presenting with altered mental status. The administration of 50% dextrose should be reserved for those patients in whom hypoglycemia is demonstrated; this practice will uphold Hippocrates' most basic principle of clinical medicine, "The physician must ... do no harm."

50% dextrose: antidote or toxin?

The empiric administration of 50% dextrose to all patients presenting to the ED with altered mental status is a standard of care predicated on the assumption that glucose administration is harmless to nonhypoglycemic patients. Considerable evidence now disputes this assumption. Glucose administration before complete cerebral ischemia in experimental animals worsens neurologic and histologic outcome. Administration of glucose during severe incomplete ischemia has a similar detrimental effect. The translation of these experimental findings into clinical practice has been slow, perhaps hindered by the frequent use of rodent models and large bolus doses of glucose. However, evidence is now provided by primate and human studies and by experimental designs using clinically relevant doses of glucose. These clinical and experimental findings in conjunction with the wide availability of a rapid bedside screen for hypoglycemia provide the rationale for an alteration in the standard of care. The empiric administration of glucose should be avoided in patients at risk of cerebral ischemia, such as those with acute stroke, impending cardiac arrest, or severe hypotension or receiving CPR. A bedside fingerstick blood glucose estimation should be performed immediately on all patients presenting with altered mental status. The administration of 50% dextrose should be reserved for those patients in whom hypoglycemia is demonstrated; this practice will uphold Hippocrates' most basic principle of clinical medicine, "The physician must...do no harm."

Inhalational and percutaneous methanol toxicity in two firefighters.

We present two cases of adult inhalational and percutaneous methanol toxicity resulting from transient exposure to vaporized methanol. Both patients complained only of a mild headache at the time of the emergency department evaluation and had normal physical examinations, normal anion gaps, and peak methanol levels of 23 and 16 mg/dL, respectively. Emergency physicians should recognize the potential for toxic transcutaneous absorption of methanol. Because of the varying relationship between clinical symptoms, physical examination findings, and anion gap values to potentially toxic methanol exposures, acquisition of empiric serum methanol levels appears warranted in appropriate situations.

Interposed abdominal compression CPR versus standard CPR in prehospital cardiopulmonary arrest: preliminary results.

Recent studies evaluating interposed abdominal compression cardiopulmonary resuscitation (IAC-CPR) have demonstrated a significant increase in cardiac output, mean arterial pressure, and cerebral perfusion compared with standard CPR. A clinical evaluation of IAC-CPR effectiveness on resuscitation outcome has not been reported. A prospective, randomized study comparing IAC-CPR with standard CPR for resuscitation of prehospital cardiopulmonary arrest was developed utilizing the Milwaukee County Paramedic System. When the paramedics arrive, standard CPR is initiated or continued, and countershocks are delivered when appropriate. The patients are randomized into IAC-CPR and standard CPR groups immediately following endotracheal intubation. Abdominal compression force is standardized to 100 mm Hg +/- 20 mm Hg by using a simple airfilled bladder and gauge to monitor each compression. Resuscitations are conducted according to standard advanced cardiac life support guidelines through continuous radio-telemetry contact with a base physician. Since October 1983, 140 patients have qualified for the study group. Seventy patients had standard CPR and 30% (21/70) were admitted to the emergency department with a rhythm and pulse, as were 34% (24/70) of the patients treated with IAC-CPR. The difference between study groups was not significant. To determine if 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.(ABSTRACT TRUNCATED AT 250 WORDS)