Old age does not negate good cerebral outcome after cardiopulmonary resuscitation: analyses from the brain resuscitation clinical trials. The Brain Resuscitation Clinical Trial I and II Study Groups.

OBJECTIVE: To assess survival after cardiac arrest and to determine whether age is an independent determinant of late mortality or poor neurologic outcome. DESIGN: Analyses using results of Brain Resuscitation Clinical Trial I (1979 to 1984) and Brain Resuscitation Clinical Trial II (1984 to 1989), two randomized, double-blind studies of outcome following cardiac arrest. SETTING: A multicenter study in 12 acute care hospitals in nine countries (Brain Resuscitation Clinical Trial I), and 24 hospitals in eight countries (Brain Resuscitation Clinical Trial II). PATIENTS: A total of 774 patients who were initially comatose after successful resuscitation from cardiac arrest. The analyses include both in- and out-of-hospital cardiac arrests. RESULTS: The 6-month mortality rate for the entire group was 81%. Mortality rate was 94% for the oldest group (> 80 yrs) compared with 68% for the youngest group (< or = 45 yrs) (p < .01). Other independent predictors of mortality were history of diabetes mellitus, inhospital arrests, arrest time of > 5 mins, history of congestive heart failure, a noncardiac cause of arrest, and cardiopulmonary resuscitation time of > 20 mins. Of the 774 patients, 27% recovered good neurologic function. There was no statistically significant difference in neurologic recovery rates by age. Multivariate analysis showed that independent predictors of good neurologic recovery were: no history of diabetes mellitus, a cardiac cause of arrest, short arrest time, and short cardiopulmonary resuscitation time. CONCLUSION: Increasing age was a factor in postresuscitation mortality, but was not an independent predictor of poor neurologic outcome.

Defibrillation and cardioversion.

To optimize the success of defibrillation, the clinician needs to minimize impedance, choose the proper energy level, apply the proper interface, select the appropriate paddle size, and deliver the shock at the earliest possible time. Other factors that may contribute to effective defibrillation include defibrillation during exhalation, maintenance of an effective airway, and correction of electrolyte abnormalities. Open chest defibrillation can be achieved at a lower dose of between 10 J and 20 J. Automated external defibrillators have increased survival of prehospital arrests. Cardioversion can generally be accomplished safely either as an elective or emergent procedure. Selection of the proper indications, protection of the airway, anticoagulation if necessary, correction of digitalis toxicity, and the utilization of adjuvant therapy ensure an optimal outcome.

Airway pressure release ventilation during acute lung injury: a prospective multicenter trial.

OBJECTIVE: To evaluate the feasibility of airway pressure release ventilation (APRV) in providing ventilatory support to patients with acute lung injury of diverse etiology and mild-to-moderate severity. DESIGN: Prospective, multicenter, nonrandomized crossover trial. SETTING: ICUs in six major referral hospitals. PATIENTS: Fifty adult patients with respiratory failure requiring mechanical ventilation and positive end-expiratory airway pressure. INTERVENTIONS: After optimization of continuous positive airway pressure (CPAP), conventional ventilation and APRV were administered sequentially for 30 mins. During APRV, the CPAP level and airway pressure release level were adjusted to prevent hypoxemia, while the degree of ventilatory support was adjusted by altering the frequency of pressure release. MEASUREMENTS AND MAIN RESULTS: Circulatory and ventilatory pressures, arterial blood gases and pH, heart rate, and respiratory rate were measured. Alveolar ventilation was augmented adequately in 47 of 50 patients by APRV. Adjustment of APRV required an increase in mean CPAP from 13 +/- 3 (SD) to 21 +/- 9 cm H2O and a release pressure of 6 +/- 5 cm H2O. This airway pressure pattern produced a mean airway pressure comparable to that pressure achieved during conventional ventilation. Failure of APRV in three patients could be attributed to an inadequate level of CPAP or an inadequate APRV rate. While maintaining oxygenation of arterial blood and circulatory function, APRV allowed a substantial (55 +/- 17%; p less than .0001) reduction in peak airway pressure compared with conventional positive pressure ventilation adjusted to deliver a comparable or lower level of ventilatory support. CONCLUSIONS: APRV is a feasible alternative to conventional mechanical ventilation for augmentation of alveolar ventilation in patients with acute lung injury of mild-to-moderate severity.

Cardiac tamponade associated with a multilumen central venous catheter.

Two patients experienced cardiac tamponade after catheterization with a multilumen central venous catheter. The authors review the problem, including recommendations for central line placement to decrease the incidence of this potentially lethal complication.