Preventing Cardiac Arrest in a Pediatric Cardiac ICU-Situational Awareness and Early Intervention Work Together!

Cardiac arrests (CAs) occur in 2.6–6% of hospitalized children with heart disease and 4–6 times more frequently in cardiac than noncardiac PICUs (1, 2). Abrupt hemodynamic deterioration leading to CA remains a common event in pediatric cardiac ICU (CICU) patients due to many etiologies that include, to name some; palliated parallel circulation physiology, shunt dependent pulmonary or systemic circulation, low cardiac output states after complex repairs, propensity to arrhythmia and poor myocardial function due to myocarditis or cardiomyopathy. Additional risk factors for CA in children with cardiac disease include neonatal age group, higher complexity of congenital heart lesion, complexity of surgical repair, and patients with single ventricle physiology after stage 1 palliation (3). Monitoring surgical and nonsurgical CICU patients for indications that CA may be imminent has focused on markers of decreased oxygen delivery such as serial lactate measurement (4), near-infrared spectroscopy (5) and “next generation” analysis of clinical variables to create an oxygen delivery index (Etiometry) (1). Combining physiologic components into pragmatic checklists (6) and clinical decision support tools (7) have shown high sensitivity and specificity in predicting CA events in PICUs. In addition to determining who is at risk of CA, it is also important to implement and assess interventions to prevent, slow down progression of instability toward CA and improve the chances of successful resuscitation from CA when it occurs. In this issue of Critical Care Medicine, Ferguson et al (8) report the results of a well-designed multiple component quality improvement intervention aimed at reducing the rate of CA in a pediatric CICU with a large population of complex surgical and nonsurgical patients, including a large number with decompensated heart failure due to myocarditis and cardiomyopathy with and without mechanical support devices. Their intervention bundle, study duration, subject number, and durable results are impressive and worthy of note. Recognizing through audit that a large percentage of CAs in their unit began with abrupt hypotension, the investigators implemented a multiple component bundle of interventions centered around early, nurse driven, administration of 1 μg/ kg of epinephrine in the event of hypotension. Over a 6-year period, a durable 56% (17.2 per 1,000 patient days to 7.6 per 1,000 patient days) decrease in rate of CA was found. An epinephrine dose, prepared based on daily physician order and stored at the bedside, was administered by the bedside nurse in the event that a patient’s blood pressure decreased to a level established on morning patient rounds by the attending cardiac intensivist. The use of 10 μg/mL concentration epinephrine boluses (“dwindle dose,” “epi spritzer,” “micro dose,” “peppinephrine”) to treat hypotension has been reported to be safe and effective and has become widespread in cardiac and noncardiac PICUs (9, 10). Low dose epinephrine administration for hypotension and bradycardia is recommended by the American Heart Association in its guidelines for cardiopulmonary resuscitation (CPR) in infants and children with cardiac disease (2). For the study by Ferguson et al (8), a decision was made to use an epinephrine dose of 1 μg/kg (1/10th “code” dose) prepared in a volume of 1 mL instead of using a dilute fixed concentration of epinephrine (10 μg/mL) in a calculated volume in order to avoid issues related to dose calculation and low administration volumes in small patients. Having an order written daily on rounds to administer the epinephrine for a set indication conceivably saved time that otherwise would have been used finding an ordering provider, preparing a bolus either of fluid or pressor or waiting for an increased vasopressor or inotrope infusion rate to have an effect. If the blood pressure rose with the epinephrine bolus, the team had additional time to figure out what was happening and potentially intervene definitively. If hemodynamics did not improve the team knew from previously published data (10), and confirmed in their study, that the outcome was likely to be challenging. Although early administration of low dose epinephrine for hypotension is the centerpiece of this article and a point that is easy to take away, there is far more here that may have had equal, if not greater impact, on the positive outcome of the study by Ferguson et al (8). The components of the bundle included a daily assessment by the rounding team of whether or not each *See also p. e542.