Andersons pediatric cardiology 1718

saturation, PA pressure, and pulmonary capillary wedge pressure, and to measure cardiac output by thermodilution The PA catheter can be particularly helpful in conditions where pressure changes and assessment of response to interventions are immediately needed, such as treatment of severe pulmonary hypertension or the response to (or appropriateness of) fluid administration However, the PA catheter, once considered a cornerstone in the management of critically ill patients, has been overshadowed by complications associated with its insertion and placement, as well as inaccuracies and difficulties with the interpretation of data.10 In patients with congenital heart disease with intracardiac shunts or valvar regurgitation, PA catheter data can be misleading or invalid Pulse Index Continuous Cardiac Output System The pulse index continuous cardiac output (PiCCO, Maquet Cardiopulmonary) is an invasive, continuous cardiac output monitor The PiCCO system utilizes transcardiopulmonary thermodilution and pulse contour analysis obtained from intraarterial and central venous catheterization The PiCCO system may present fewer technical challenges than PA catheters, and studies have demonstrated close correlation in the data generated between systems.11 Some of the identified challenges with this PiCCO system are its invasive nature and the necessity of frequent calibration due to data drift from the pulse contour analysis techonology.12 Another downside of this system is its invasive nature, requiring arterial catheterization with a 3F or 4F catheter, often necessitating cannulation of the femoral artery for smaller patients, which presents an additional risk of arterial compromise Near-Infrared Spectroscopy NIRS monitoring provides a noninvasive tool for continuous monitoring of regional tissue oxygen saturation or oximetry in critically ill children.13 The NIRS monitor analyzes the concentration and ratio of oxygenated to deoxygenated hemoglobin and assists at determining the balance between oxygen supply and demand, and is most commonly used to monitor brain and somatic oxygen saturation The NIRS monitor employs single-use adhesive patches with an integrated near infrared light source and photodetector, which are applied close to the tissue of interest, for example the forehead or abdomen In contrast to pulse oximetry, the NIRS monitor evaluates the nonpulsatile signal, reflecting the oxygen saturation of the microcirculation The data derived from NIRS cerebral oximetry monitoring have demonstrated good correlation with jugular venous saturations.14,15 The cerebral NIRS also assesses regional cerebral oxygen saturation and can identify inadequate cerebral perfusion that is linked to neurologic injury and adverse outcomes.16 Single-site cerebral and two-site NIRS (cerebral and somatic) are being increasingly used in patients with heart disease, and there is growing data to support that this may predict adverse outcomes including the need for extracorporeal membrane oxygenation (ECMO), neurodevelopmental impairment or death in selected patient groups.16–18 Management of Acute Circulatory Failure The management of acute circulatory failure varies according to its etiology In children with congenital heart disease the presentation is more predictable, giving the opportunity for timely preventative interventions Conversely, in children with cardiomyopathy presenting with acute circulatory failure, such prevention is not possible In this case, a more reactive approach with early investigations, establishment of therapeutic targets, and appropriate intervention is necessary Early Recognition Early recognition, appropriate treatment, and rapid reversal of acute circulatory failure or any shock state have been shown to influence outcomes in critically ill patients A recent study in pediatrics revealed that the predominant factor that reduces mortality and neurologic morbidity in children transported to tertiary care pediatric hospitals is the reversal of shock through early recognition and resuscitation in the referring emergency department.19 Detailed Investigation In children with circulatory instability early after surgery for congenital heart disease or in those where the cause of this is unclear, electrocardiography (seeking out arrhythmias) echocardiography, cardiac catheterization, or computed tomographic angiography (investigating cardiac function and residual lesions) may be necessary for the identification of the underlying cause Therapeutic Targets One of the fundamental tenets of the management of acute circulatory failure is to restore the systemic oxygen balance by manipulating one or more of the following: ■ Systolic function ■ Diastolic function ... patients A recent study in pediatrics revealed that the predominant factor that reduces mortality and neurologic morbidity in children transported to tertiary care pediatric hospitals is the reversal of shock through early recognition and