Cerebral physiology in paediatric cardiopulmonary bypass

Abstract

FKCPCPurpose: To analyze studies of neurological injury after open-heart surgery in infants and children and to discuss the effects of cardiopulmonary bypass, hypothermia and deep hypothermic circulatory arrest on cerebral blood flow, cerebral metabolism and brain temperature. Source: Articles were obtained from the databases, Current Science and Medline, from 1966 to present. Search terms include cardiopulmonary bypass(CPB), hypothermia, cerebral blood flow(CBF), cerebral metabolism and brain temperature. Information and abstracts obtained from meetings on the topic of brain and cardiac surgery helped complete the collection of information. Principal findings: In adults the incidence of neurological morbidity is between 7 to 87% with stroke in about 2-5%, whereas the incidence of neurological morbidity increases to 30% in infants and children undergoing cardiopulmonary bypass. Besides the medical condition of the patient, postoperative cerebral dysfunction and neuronal ischaemia associated with cardiac surgery in infants and small children are a combination of intraoperative factors. Deep hypothermic circulatory arrest impairs CBF and cerebral metabolism even after termination of CPB. Inadequate and/or non-homogenous cooling of the brain before circulatory arrest, as well as excessive rewarming of the brain during reperfusion are also major contributory factors. Conclusion: Newer strategies, including the use of low-flow CPB, pulsatile CPB, pH-stat acid-base management and a cold reperfusion, are being explored to ensure better cerebral protection, Advances in monitoring technology and better understanding of the relationship of cerebral blood flow and metabolism during the different modalities of cardiopulmonary bypass management will help in the medical and anaesthetic development of strategies to improve neurological and developmental outcomes.Objectif: Examiner les Etudes portant sur les atteintes neurologiques survenues apr& une chirurgie b. coeur ouvert chez les bEbEs et les enfants et discuter des effets de la circulation extracorporelle, de l'hypothermie et de l'arr~t circulatoire sous hypothermie profonde sur le debit sanguin c&~bral, sur le m&abolisme c&Ebral et sur la temperature du cerveau. Sources documentaires : Des articles ont &E choisis ~ partir de bases de donnEes, Current Science et Medline, de 1966 ~ aujourd'hui. Les mots-cl& utilis& Etaient : circulation extracorporelle (CEC), hypothermie, debit sanguin cErEbral (DSC), mEtabolisme cErEbral et temperature du cerveau. Les informations et les rEsumEs obtenus & la suite de sEminaires sur le cerveau et la chirurgie cardiaque ont permis de completer la cueillette de donn&s. I)onn&s principales : Chez les adultes, l'incidence de morbiditE neurologique avec accident vasculaire est de 7 87 % clans 2 ~. S % des cas tandis que l'incidence de morbiditE neurologique augmente & 30 % chez les bEb~s et les enfants subissant une circulation extracorporelle. La condition mEdicale du patient raise & part, le d&~glement cErEbral postop&atoire et l'ischEmie neu...

Aortic Outflow Cannula Tip Design and Orientation Impacts Cerebral Perfusion During Pediatric Cardiopulmonary Bypass Procedures

“…Clinical studies have suggested several aspects of patient management before and after the circulatory arrest (i.e., during low-flow CPB) that are as important in protecting the patient, including hemodynamic factors like flow pulsatility, thermal factors like adequate cooling of the brain, cold reperfusion and re-warming time, 37 as well as clinical factors that predispose neurological risk during CPB, like perioperative glucose levels. 13 While inferences in regard to these factors is difficult to obtain from retrospective studies and randomized clinical trials may help unravel some of these mysteries, lack of uniformity of in equipment and clinical practice makes data collection for CPB procedures in different institutions practically difficult.…”

“…Despite advances in surgical techniques leading to decreased mortality after repair of complex congenital cardiac conditions, neurologic morbility is still significant. Given that the incidence of neurological morbidity is as high as 30% in infants and children 8,37 undergoing CPB in sharp contrast with 2-5% amongst adults, the issue of aortic perfusion during CPB deserves attention in young patients.…”

Cerebral Blood Flow and Autoregulation After Pediatric Traumatic Brain Injury

“…Thereafter, CMRglu decreases, and approaches adult rates (19-33 μmol/100g/min) [26]. The higher CMRO 2 and CMRglu in children may be related to the higher age-related changes in CBF and may be due to intact flow-metabolism coupling [22,26,37]. It appears that changes in CMRO 2 , CMRglu, and CBF mirror each other and peak during early childhood; possibly reflecting maturational changes during this period.…”

“…Most cerebrovascular data in children are derived from critically ill neonates [1][2][3]. The paucity of information in this area leaves clinicians without a clear understanding of how to manage hemodynamics, particularly during critical illness.…”

Plasma cytokines do not reflect expression of pro‐ and anti‐inflammatory cytokine mRNA at organ level after cardiopulmonary bypass in neonatal pigs*

“…Plasma cytokines do not reflect expression of pro-and anti-inflammatory cytokine mRNA at organ level after cardiopulmonary bypass in neonatal pigs # Acta Anaesthesiologica Scandinavica 47 (2003) C ARDIOVASCULAR, pulmonary and renal dysfunction are common complications after cardiac surgery performed with cardiopulmonary bypass (CPB) and are especially pronounced in the paediatric patient (1)(2)(3). This postoperative temporary organ dysfunction is thought to be a consequence of the systemic inflammatory response elicited by cardiac surgery and CPB (4).…”