Assessment of microcirculatory alteration by a vascular occlusion test using near-infrared spectroscopy in pediatric cardiac surgery: effect of cardiopulmonary bypass.

OBJECTIVES: Cardiopulmonary bypass cause microcirculatory alterations. Near infrared spectroscopic measurement of tissue oxygen saturation and vascular occlusion test are novel technologies for assessing the microcirculatory function of peripheral tissue specifically in patients undergoing cardiac surgery with cardiopulmonary bypass.Our study aimed to evaluate dynamic microcirculatory function using the vascular occlusion testing during cardiac surgery in pediatric patients. METHODS: 120 pediatric patients were scheduled. Children had continuous regional oxygen saturation monitoring using near infrared spectroscopy and vascular occlusion test. Vascular occlusion test was performed five times; before induction (T1), after induction (T2), then during cardiopulmonary bypass with full flow (T3), after the termination of CPB (T4) and after sternum closure (T5). RESULTS: Basal value was the lowest at T3 and this value was significantly different among measurements (p < 0,01).Values for maximum and minimum tissue oxygen saturation were the lowest at T3 (83,4 and 52,9%).The occlusion slope varied significantly among measurements (p < 0,01).Reperfusion slopes were significantly different among measurements (p < 0,01) with a further progressive decrease in reperfusion slope with duration of cardiopulmonary bypass. CONCLUSION: Microcirculatory function can assessed using VOT with forearm Near-infrared spectroscopy derived variables during cardiopulmonary bypass in pediatric cardiac surgery. Noninvasive assessment of microcirculatory perfusion during cardiopulmonary bypass can further help evaluate and improve circulatory support techniques. TRIAL REGISTRATION: The research Project was registered at ClinicalTrials.gov (NCT06191913).

Introduction to a Norwood program in an emerging economy: learning curve of a single center.

BACKGROUND: There has been a notable improvement in the outcome of stage 1 palliation for hypoplastic left heart syndrome (HLHS) in recent years. Nevertheless, developing a new Norwood program requires a steep learning curve, especially in emerging economies where rapid population growth brings a high volume of patients but, on the other hand, resources are limited. In this paper we aimed to summarize the initial results of a single center. METHODS: Hospital records of 21 patients were reviewed for all patients having a stage 1 palliation procedure for HLHS between May 2011 and May 2013. There were 13 male (62%) and 8 female (38%) patients. Median age was 14 days (range, 4-74 days) and median weight was 3030 g (2600-3900 g). HLHS was defined as mitral or aortic stenosis or atresia (or both) in the presence of normally related great vessels and a hypoplastic left ventricle. Transthoracic echocardiography was the diagnostic modality used in all patients. All procedures but one were performed using an antegrade selective cerebral perfusion method and moderate hypothermia. Cerebral perfusion was monitored with cerebral oximetry in all patients. Modified ultrafiltration was routinely used in all patients. RESULTS: Overall hospital mortality was 47.6% (n = 10). Mortality rates considerably decreased from the first year to second year (69% and 12.5% respectively). No risk factors were identified for mortality. CONCLUSIONS: Surgical palliation of neonates with hypoplastic left heart syndrome continues to be a challenge. To decrease the overall mortality nationwide and improve outcomes, a referral center with a dedicated team is necessary in emerging economies.