Cerebral Oxygenation During Pediatric Cardiac Surgery Using Deep Hypothermia Circulatory Arrest

Background Deep hypothermic circulatory arrest is a widely used technique in pediatric cardiac surgery that carries a risk of neurologic injury. Previous work in neonates identified distinct changes in cerebral oxygenation during surgery. This study sought to determine whether the intraoperative changes in cerebral oxygenation vary between neonates, infants, and children and whether the oxygenation changes are associated with postoperative cerebral dysfunction. Methods The study included eight neonates, ten infants, and eight children without preexisting neurologic disease. Cerebrovascular hemoglobin oxygen saturation (SCO2), an index of brain oxygenation, was monitored intraoperatively by near-infrared spectroscopy. Body temperature was reduced to 15 degrees C during cardiopulmonary bypass (CPB) before commencing circulatory arrest. Postoperative neurologic status was judged as normal or abnormal (seizures, stroke, coma). Results Relative to preoperative levels, the age groups experienced similar changes in SCO2 during surgery: SCO2 increased 30 +/- 4% during deep hypothermic CPB, it decreased 62 +/- 5% by the end of arrest, and it increased 20 +/- 5% during CPB recirculation (all P < 0.001); after rewarming and removal of CPB, SCO2 returned to preoperative levels. During arrest, the half-life of SCO2 was 9 +/- 1 min in neonates, 6 +/- 1 min in infants, and 4 +/- 1 min in children (P < 0.001). Postoperative neurologic status was abnormal in three (12%) patients. The SCO2 increase during deep hypothermic CPB was less in these patients than in the remaining study population (3 +/- 2% versus 33 +/- 4%, P < 0.001). There were no other significant SCO2 differences between outcome groups. Conclusions Brain oxygenation changed at distinct points during surgery in all ages, reflecting fundamental cerebral responses to hypothermic CPB, ischemia, and reperfusion. However, the changes in SCO2 half-life with age reflect developmental differences in the rate of cerebral oxygen utilization during arrest, consistent with experimental work in animals. Certain intraoperative cerebral oxygenation patterns may be associated with postoperative cerebral dysfunction and require further study.

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Cerebral Oxygenation during Pediatric Cardiac Surgery: Identification of Vulnerable Periods using Near-infrared Spectroscopy

Research & Innovation in Anesthesia ◽

10.5005/jp-journals-10049-0004 ◽

2016 ◽

Vol 1 (1) ◽

pp. 15-18

Author(s):

Mehul Mange ◽

Manjula Sarkar

Keyword(s):

Cardiac Surgery ◽

Infrared Spectroscopy ◽

Near Infrared Spectroscopy ◽

Near Infrared ◽

Cerebral Oxygenation ◽

Circulatory Arrest ◽

Supply And Demand ◽

Pediatric Cardiac Surgery ◽

Promising Tool ◽

Neurologic Sequelae

ABSTRACT Objective Neurologic sequelae remain a well-recognized complication of pediatric cardiac surgery. The aetiology of neurologic injury is almost certainly multifactorial, imbalance between cerebral oxygen supply and demand is likely to play an important role. We sought to measure regional cerebral oxygenation in children undergoing cardiac surgery using nearinfrared spectroscopy to ascertain such vulnerable periods. Materials and methods This study is an observational study of 18 children (median age 1.3 years) undergoing cardiac surgery. Regional cerebral oxygenation was monitored using the INVOS3100 cerebral oximeter and related to hemodynamic parameters at each stage of the procedure. Results Prior to the onset of bypass, 10 patients had a decrease in regional cerebral oxygenation, reaching a saturation less than 35% in 5 cases. The most common cause was handling and dissection around the heart prior to and during caval cannulation. With institution of bypass, regional cerebral oxygenation increased. Discontinuation of bypass caused a precipitous decrease in regional cerebral oxygenation in three patients, reaching less than 40%. Conclusions These observations suggest that the pre- and early post-bypass periods are vulnerable times for provision of adequate cerebral oxygenation. Near-infrared spectroscopy is a promising tool for monitoring O2 supply/demand relationships especially during circulatory arrest. How to cite this article Mange M, Sarkar M. Cerebral Oxygenation during Pediatric Cardiac Surgery: Identification of Vulnerable Periods using Near-infrared Spectroscopy. Res Inno Anaesth 2016;1(1):15-18.

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The Role of Deep Hypothermia in Cardiac Surgery

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18137061 ◽

2021 ◽

Vol 18 (13) ◽

pp. 7061

Author(s):

Radosław Gocoł ◽

Damian Hudziak ◽

Jarosław Bis ◽

Konrad Mendrala ◽

Łukasz Morkisz ◽

...

Keyword(s):

Cardiac Surgery ◽

Aortic Arch ◽

Cerebral Oxygenation ◽

Circulatory Arrest ◽

Deep Hypothermia ◽

Body Core Temperature ◽

Congenital Defects ◽

Acute Type ◽

Organ Protection ◽

Blood Temperature

Hypothermia is defined as a decrease in body core temperature to below 35°C. In cardiac surgery, four stages of hypothermia are distinguished: mild, moderate, deep, and profound. The organ protection offered by deep hypothermia (DH) enables safe circulatory arrest as a prerequisite to carrying out cardiac surgical intervention. In adult cardiac surgery, DH is mainly used in aortic arch surgery, surgical treatment of pulmonary embolism, and acute type-A aortic dissection interventions. In surgery treating congenital defects, DH is used to assist aortic arch reconstructions, hypoplastic left heart syndrome interventions, and for multi-stage treatment of infants with a single heart ventricle during the neonatal period. However, it should be noted that a safe duration of circulatory arrest in DH for the central nervous system is 30 to 40 min at most and should not be exceeded to prevent severe neurological adverse events. Personalized therapy for the patient and adequate blood temperature monitoring, glycemia, hematocrit, pH, and cerebral oxygenation is a prerequisite and indispensable part of DH.

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