Comparison of two different extracorporeal circuits on cerebral embolization during cardiopulmonary bypass in children

EEG features of brain injury during extracorporeal membrane oxygenation in children

OBJECTIVE

To examine EEG features of major pathophysiology in children undergoing extracorporeal membrane oxygenation (ECMO).

METHODS

This was a single-center, retrospective study of 201 pediatric patients on ECMO, using the first 24 hours of continuous EEG (cEEG) monitoring, collating background activity and electrographic seizures (ES) with imaging, ECMO type, and outcome.

RESULTS

Severely abnormal cEEG background occurred in 12% (25/201), and was associated with death (sensitivity 0.23, specificity 0.97). ES occurred in 16% (33/201) within 3.2 (0.6-20.3) hours (median [interquartile range]) of cEEG commencement, and higher ES burden was associated with death. ES was always associated with ipsilateral injury (p = 0.006), but occurred in only one-third of cases with abnormal imaging. In 28 patients with isolated hemisphere lesion, type of arterial ECMO cannulation was associated with side of injury: right carotid cannulation was associated with right hemisphere lesions, and ascending aorta cannulation with left hemisphere lesions (odds ratio, 0.29 [95% confidence interval, 0.08-0.98], p = 0.03).

CONCLUSIONS

After starting ECMO, cEEG background activity has the potential to inform prognosis. Type of arterial (carotid vs aortic) ECMO correlates with side of focal cerebral injury, which in ≈33% is associated with presence of ES. We hypothesize that the differential distribution reflects abnormal flow dynamics or embolic injury.

Neurologic complications of congenital heart disease and its treatment

Advances in surgical and medical management have dramatically improved the survival of individuals with congenital cardiac anomalies. Various neurologic complications occur in association with congenital heart disease, including cognitive impairment and ischemic stroke. The likelihood of stroke is greatest in individuals with severe structural cardiac defects such as tetralogy of Fallot, transposition of the great arteries, or hypoplastic left heart syndrome. A persistent foramen ovale adds little or no additional stroke risk unless it is associated with an atrial septal aneurysm or other anomaly. Individuals with congenital heart disease caused by genetic abnormalities are apt to have other anomalies as well. Complications related to correction of cardiac anomalies include seizures, ischemia, stroke, and movement disorders.

Generation, detection and prevention of gaseous microemboli during cardiopulmonary bypass procedure

Neuropsychological injury after cardiopulmonary bypass (CPB) is one of the most serious and costly complications arising from the procedure. Gaseous microemboli (GME) have long been implicated as one of the principal causes. There are two major sources of GME: surgical and manual manipulation of the heart and arteries; and the components of the extracorporeal circuit, including the type of pump, different perfusion modes, the design of the oxygenator and reservoir, and the use of vacuum assisted venous drainage (VAVD), all of which have a great impact on the delivery of existing GME to the patients. Transcranial cranial Doppler (TCD) has been used for more than two decades to assess and monitor the quality of extracorporeal perfusion with regard to the blood flow velocity of the middle cerebral arteries (MCA) and emboli detection, contributing to the achievement of better perfusion results. The Emboli Detection and Classification (EDAC) Quantifier has been able to detect and track microemboli in CPB circuits up to 1,000 microemboli per second at flow rates ranging from 0.2 L/min to 6.0 L/min. The deleterious effects of GME are multiple, including damage to the cerebral vascular endothelium, disruption of the blood-brain barrier, complement activation, leukocyte aggregation, increased platelet adherence, and fibrin deposition in the micro-vasculature. Improvements in perfusion equipment and in perfusion and surgical techniques have led to a dramatic reduction in the occurrence of GME during cardiac surgery. Although the clinical relevance of cerebral air embolization in causing neurological damage is unclear, every single person involved in perfusion and surgical technology should be aware of the risk of embolization and strictly regulate clinical behavior. Related research should also be done to improve the design of circuit components and clinical practice with a view to eliminating air bubbles during CPB procedure.

Transient cortical blindness after heart surgery in a child patient -A case report-

Visual loss occurring after pediatric cardiac surgery employing cardiopulmonary bypass (CPB) is relatively rare but the risk is substantial. Compromised cerebral perfusion due to a CPB related micro-embolization and inflammatory vascular changes as well as reduced oxygen carrying capacity in hemodilution and hypothermia during CPB might be major contributing factors to the development of postoperative visual loss after cardiac surgery with CPB. A case of immediate but transient postoperative visual loss was encountered in a 21-month-old male who underwent tricuspid valve surgery. Despite routine intraoperative measures to maintain an adequate perfusion pressure throughout the procedure, postoperative computed tomography revealed a subacute infarct in his occipital lobe. Recovery began on postoperative day 28, and the patient's vision was restored by 31 days.

High-intensity transient signals during laparoscopic surgery in children

BACKGROUND

Laparoscopic interventions in children gain increasing popularity. Pneumoperitoneum as applied during laparoscopic surgery can induce gas emboli formation, but it is unclear whether this is associated with cerebral embolic events. To investigate the hypothesis that pneumoperitoneum causes cerebral emboli in children, the number and intensity of high-intensity transient signals (HITS) detected using transcranial Doppler ultrasonography were assessed before and after induction of pneumoperitoneum.

METHODS

Twenty children were monitored during laparoscopic surgery. General anaesthesia was performed using sevoflurane and sufentanil or alfentanil. Pressure-controlled ventilation was adapted to maintain end-tidal Pco(2) (Pe'(co(2))) between 4.7 and 6.0 kPa. Baseline measurement of HITS rate, cerebral blood flow velocity, and mean arterial pressure (MAP) were recorded during steady-state anaesthesia before skin incision and during pneumoperitoneum with intra-abdominal pressure of 1.6-2.0 kPa applied using CO(2).

RESULTS

In 14 children (70%), HITS were detected during baseline and pneumoperitoneum. Three additional children (15%) developed HITS during pneumoperitoneum only and another three children (15%) presented no HITS during the investigation period. MAP and cerebral blood flow velocity increased with pneumoperitoneum.

CONCLUSIONS

HITS are present in 70% of paediatric surgical patients under balanced anaesthesia before surgical interventions. Pneumoperitoneum further increased the occurrence of HITS.

Complications relating to perfusion and extracorporeal circulation associated with the treatment of patients with congenital cardiac disease: consensus definitions from the Multi-Societal Database Committee for Pediatric and Congenital Heart Disease

The International Consortium for Evidence-Based Perfusion (www.bestpracticeperfusion.org) is a collaborative partnership of societies of perfusionists, professional medical societies, and interested clinicians, whose aim is to promote the continuous improvement of the delivery of care and outcomes for patients undergoing extracorporeal circulation. Despite the many advances made throughout the history of cardiopulmonary bypass, significant variation in practice and potential for complication remains. To help address this issue, the International Consortium for Evidence-Based Perfusion has joined the Multi-Societal Database Committee for Pediatric and Congenital Heart Disease to develop a list of complications in congenital cardiac surgery related to extracorporeal circulation conducted via cardiopulmonary bypass, extracorporeal membrane oxygenation, or mechanical circulatory support devices, which include ventricular assist devices and intra-aortic balloon pumps. Understanding and defining the complications that may occur related to extracorporeal circulation in congenital patients is requisite for assessing and subsequently improving the care provided to the patients we serve. The aim of this manuscript is to identify and define the myriad of complications directly related to the extracorporeal circulation of congenital patients.

Cerebral arterial air embolism in a child after intraosseous infusion

Cerebral arterial air embolism (CAAE) has been reported as a rare complication of medical intervention. There has been one reported case of CAAE after the use of an intraosseous infusion (IO) system. We report on a case of CAAE after tibial IO infusion in a 7-month-old girl during resuscitation.