Immediate countershock treatment of asystole

Apparent asystole: are we missing a lifesaving opportunity?

The use of ultrasonography is rapidly expanding in emergency medicine. Real-time assessment offers clues to prompt diagnosis and creates opportunities for speedy intervention. We present a case of 'cardiac monitor asystole' that proved to be ventricular fibrillation on ultrasound examination. Uniquely this case demonstrates that this, typically unrecognised, form of ventricular fibrillation responds to desynchronised defibrillation, with restoration of perfusion for approximately 30 min. With increasing access to ultrasound we believe that further research is indicated to determine whether some cases of apparent asystole may best be treated by defibrillation, presenting an opportunity to save more lives than current protocols achieve.

Mastering pediatric cardiopulmonary resuscitation

Premature and unexpected death, especially in children, is tragic and very unacceptable. Effective treatments for sudden death of pediatric patients continue to emerge. Modern cardiopulmonary resuscitation function began with the widespread introduction of closed-chest cardiac massage in 1960; however, despite 35 years of research and refinement, more than 90% of children who receive cardiopulmonary resuscitation do not survive. This article summarizes and expands on current treatment concepts for pediatric sudden death. Emphasis is placed on procedures and techniques that likely are accessible in most medical centers caring for critically ill and injured children.

Initial countershock in the treatment of asystole

BACKGROUND

Routine provision of defibrillatory countershock (CS) in the initial management of asystolic cardiac arrest has been advocated because certain cases of ventricular fibrillation (VF) may present as asystole (AS).

OBJECTIVE

To determine the value of initial CS versus endotracheal intubation and pharmacologic therapy alone in the treatment of asystolic cardiac arrest.

DESIGN/PARTICIPANTS

A retrospective analysis of data collected prospectively during a multicenter study of out-of-hospital cardiac arrest. The study subjects were all patients whose initial cardiac arrest rhythm was AS and were treated with standard advanced cardiac life support (ACLS).

SETTING

Six urban emergency medical services (EMS) systems.

INTERVENTION

Patients in AS were treated initially with CS followed by ACLS therapy (CS Group), and were compared to those patients receiving endotracheal intubation and pharmacologic therapy alone (No CS Group).

OUTCOME MEASURES

Those receiving initial CS were compared to those not receiving CS using both Chi-square and logistic regression analysis. Outcome parameters included: rates of return of spontaneous circulation (ROSC), emergency department admission, hospital admission and hospital discharge.

RESULTS

Of the 194 patients presenting with AS, 77 received CS as their initial therapy. Of these, 13 (16.9%) had ROSC compared to 27 of the 117 (23.1%) from the No CS Group (P = 0.30). Emergency department and hospital admission rates were not significantly different; 13.0% versus 18.0% (P = 0.36), and 13.0% versus 11.1% (P = 0.69) for CS versus No CS, respectively. None of the patients in the CS Group were discharged alive versus two (1.7%) from No CS (P = 0.52). Of 42 patients with bystander-witnessed cardiac arrests, 13.3% in the CS Group had ROSC compared to 40.7% in the No CS Group (P = 0.07). Emergency department admission rates were 6.7% for the CS Group and 33.3% for the No CS Group (P = 0.07); while hospital admission rates were 6.7% and 22.2%, respectively (P = 0.39). When these comparisons were adjusted for bystander-initiated CPR, CPR interval, and paramedic response interval, the P-values became 0.10, 0.05 and 0.17, respectively.

CONCLUSIONS

Although, statistically, the results for both groups were not distinguishable, outcomes for asystolic patients had a tendency to be better when the initial therapy did not involve CS. Larger study populations are recommended to confirm these preliminary observations.

Prehospital countershock treatment of pediatric asystole

Prehospital care was retrospectively reviewed in 117 pulseless nonbreathing (PNB) pediatric patients (0 to 18 years of age) to determine the effects of immediate countershock treatment of asystole. Of 90 (77%) children with an initial rhythm of asystole, 49 (54%) received countershock treatment. Rhythm change occurred in ten (20%) of the asystolic children who received countershock treatment. Three of the countershocked asystolic children were successfully resuscitated, but none survived. Rhythm change occurred in nine (22%) of the asystolic children not countershocked. Six were successfully resuscitated, and one survived. The two groups (countershocked asystole v noncountershocked asystole) did not differ significantly in age, sex, witnessed arrest, witnessed arrest with bystander basic life support (BLS), prehospital endotracheal intubation, both intubation and vascular access success, or diagnosis. However, prehospital vascular access was successfully established in a significantly greater number of countershocked patients (P less than .05). The mean times to the scene, at the scene, and to the hospital for the countershocked v noncountershocked asystolic patients were 6.2, 23.8, and 6.1 v 5.9, 14.7 and 7.0 minutes. The mean time at the scene was significantly greater in the countershock group (P less than .001). The successful performance of prehospital endotracheal intubation was significantly associated with rhythm change (P less than .05). Patients age, witnessed arrest, witnessed arrest with bystander BLS, successful establishment of prehospital vascular access, diagnosis, and countershock treatment were not significantly associated with rhythm change. In conclusion, prehospital countershock treatment prolonged prehospital care time and was not associated with rhythm change in asystolic children. Therefore, prehospital countershock treatment of asystolic children is not recommended.

The frequency of 'occult' ventricular fibrillation masquerading as a flat line in prehospital cardiac arrest

We investigated the frequency with which a "vector of ventricular fibrillation" may exist in persons in prehospital cardiac arrest. Emergency medical technicians trained in defibrillation were directed to record the rhythm in three different monitor leads whenever they noted an initial flat line. Before these lead switches, the technicians performed a flat line protocol that included inspection of the lead connections to the patient and to the defibrillator, and checks of the calibration and battery status of the devices. They performed this flat line protocol for 127 cardiac arrest patients; 118 were in confirmed asystole after technical problems were corrected. Ventricular fibrillation was detected in only three (2.5%) when the monitor lead was switched. Initial technical problems were more frequent and were identified for ten patients (8%). The frequency of occult ventricular fibrillation (three of 118 asystolic patients) yields a 95% confidence that the true frequency is no greater than 8% to 9%. This suggests that ventricular fibrillation masquerading as asystole is rare. These data do not support protocols for empiric countershocks of patients with an initial flat line on the monitor.

Prehospital care of the pulseless, nonbreathing pediatric patient

The performance of life-saving procedures by prehospital care personnel was reviewed in the cases of 114 pulseless, nonbreathing pediatric patients. Children 18 months to 18 years of age had a significantly greater chance of having prehospital endotracheal intubation and vascular access established compared to children younger than 18 months of age. For all patients, witnessed arrest and initial rhythm of ventricular fibrillation were significantly associated with survival. In the younger children, endotracheal intubation also was associated significantly with survival. Nine (8%) patients survived, and only three of the survivors were without neurologic sequelae. The number of neurologically intact survivors was too small to show a statistically significant association with these factors.

Cardiopulmonary resuscitation. A current perspective

Cardiopulmonary resuscitation is effective if established early and coupled with specific therapeutic interventions. Most cardiopulmonary arrest is due to ventricular fibrillation and early defibrillation offers the highest probability of success. External cardiac compression alone is inadequate to provide adequate perfusion to vital organs and, therefore, cannot sustain life unless coupled with advanced therapeutic interventions. Many new techniques for increasing flow have been developed, but have not been established clinically. The American Heart Association guidelines for CPR are still valid and are the basis for our current CPR. A practical perspective is presented whereby the therapeutic interventions are pursued systematically in an expeditious and coordinated fashion so that the key interventions are made within the first 10 to 15 minutes of the arrest.

Traumatic cardiac arrest: scope of paramedic services

The challenge of the 1960s to ambulance care provision was the stimulus for the emergence of prehospital advanced life support (ALS) being provided by paramedic personnel. While services for cardiac disease have been accepted, paramedic activities for the trauma victim continue to be a concern for many trauma surgeons. The capability and success rate of treatment, and the time spent at the scene and during transport to the hospital have raised questions about the overall need for paramedic services. Our study period was from January 1, 1981, to December 31, 1982, and it covered 95 clinically dead trauma victims who were first seen and subsequently treated by paramedics working in a medically controlled emergency medical services system. Endotracheal intubation was successful in 81 of the patients (85%). Esophageal obturator airway use was viewed as unsuccessful intubation. Intravenous (IV) access utilizing 16-gauge angiocaths was placed successfully by a peripheral or jugular vein in 70 patients (74%). Thirty-three patients averaged 860 mL volume infusion (30 to 3,000 mL). Average scene time was 22 minutes. Scene time of patients with unsuccessful IV and endotracheal intubation was 14 minutes (P = .07). Fourteen patients (14.7%) were admitted to the operating room or intensive care unit. Only three of the study group (3.2%) survived.