Postoperative Cardiac Arrest in Cardiac Surgery–How to Improve the Outcome?

BACKGROUND: In the early postoperative period after cardiac surgery the heart may be temporarily dysfunctional and prone to arrhythmias due to the phenomenon of myocardial stunning, vasoplegic syndrome, systemic inflammatory response syndrome (SIRS), electrolyte disturbances, operative trauma and myocardial edema. Most cases of cardiac arrest after cardiac surgery are reversible. OBJECTIVE: To analyse the factors that may influence the outcome of cardiac arrest after adult and pediatric cardiac surgery. METHODS: Retrospective analysis that included cardiac surgical procedures (886 adult and 749 pediatric patients) performed during the 18 month period of this study at Queen Alia Heart Institute/ Amman, Jordan. All cardiac arrest events were recorded and analysed. Data was collected on Utstein style templates designed for the purpose of this study. The outcome of cardiac arrest is examined as an early outcome (ROSC or lethal outcome) and late outcome (full recovery, recovery with complications, or in-hospital mortality). Factors that may influence the outcome of cardiac arrest were recorded and statistically analysed. Ethical committee approval obtained. RESULTS: The overall mortality rate was 3.3%. Cardiac arrest occurred in 114 patients (6.97%). The age of patients ranged from 5 days to 82 years and constituted 66 pediatric and 48 adult patients. Most pediatric cardiac arrests manifested as non-shockable rhythms (77%). Most in-hospital cardiac arrests occurred in the intensive care unit (86.5%). The majority of patients were mechanically ventilated at the time of occurrence of arrest (62.5% and 54.5% in adult and pediatric patients, respectively). Average time of cardiopulmonary resuscitation was 32.24 minutes. Overall, CA survival was 20% higher in the paediatric sub-group (full recovery rate of 51.5%). Neurological injury was slightly lower in pediatric than adult cardiac arrest survivals. (2% vs. 3%). CONCLUSION: Shockable rhythms are more common in adult cardiac arrest, while non-shockable rhythms are more frequent in the pediatric sub-population. Hemodynamic monitoring, witnessed-type of cardiac arrest, non-interrupted cardiac massage, and early recognition of cardiac tamponade are the factors associated with higher rates of survival.