Clinical Real‐Time Monitoring of Gaseous Microemboli in Pediatric Cardiopulmonary Bypass

Abstract

We describe the occurrence and distribution of gaseous microemboli with real-time monitoring in a pediatric cardiopulmonary bypass (CPB) circuit and in the cerebral circulation of patients using the Emboli Detection and Classification (EDAC) system and transcranial Doppler (TCD). Four patients (weights 3.2-13.8 kg) were studied. EDAC monitors were located on the venous line and on the postfilter arterial line to measure gaseous microemboli in the CPB circuit. TCD was used to measure high-intensity transient signals (HITS) in the middle cerebral artery. Before the initiation of CPB, EDAC detected gaseous microemboli in two cases when giving volume through the arterial line. At the initiation of CPB, gross air appeared in the venous line and gaseous microemboli were detected in the arterial line in all patients. EDAC detected a total of 3192-14 699 gaseous microemboli in the arterial line during the whole CPB period, more than 99% of which were smaller than 40 microns. After cessation of CPB, EDAC detected gaseous microemboli in the arterial line in all cases. The TCD detected HITS in two cases (25 and 315), and detected no HITS in two cases. We observed that the venous line acted as a principal source of gaseous microemboli, particularly when using vacuum-assisted venous drainage, and that a significant number of these gaseous microemboli smaller than 40 microns were subsequently transferred to the patient. Using EDAC and TCD together could strengthen the monitoring of gaseous microemboli in the extracorporeal circuit and cerebral circulation.

Improved Cerebral Oxygen Saturation and Blood Flow Pulsatility With Pulsatile Perfusion During Pediatric Cardiopulmonary Bypass

“…Although present findings support the conclusion that pulsatile flow has distinct advantages over nonpulsatile flow in brain protection during CPB, at least at advanced time points (24) or emboli detection and classification (EDAC) quantification (25), measures which may have enhanced results obtained. TCD data indicated that nonpulsatile rather than pulsatile perfusion resulted a lower decrease in PI at the before XC time point, which may possibly have been because of the variances in hemodynamic stability as surgical teams prepared for XC administration.…”

Impact of Translational Research on Optimization of Neonatal Cardiopulmonary Bypass Circuits and Techniques—The Penn State Health Approach

“…In our operating room, two Emboli Detection and Classification (EDAC) probes are inserted into the venous and arterial lines to monitor GME entry into the circuit and delivery to the patient. Our clinical studies demonstrated that the venous line is the main source of GME, particularly when using VAVD (21,22). The negative pressure in the venous reservoir added by VAVD may increase the formation and delivery of GME.…”

Generation, Detection and Prevention of Gaseous Microemboli during Cardiopulmonary Bypass Procedure

“…wang et al observed that GMe were detected in the arterial line during volume administration both before and after cPB. they concluded the circuit priming technique should be optimized to eliminate GMe in the extracorporeal circuit before cPB (33). cO 2 flushing of the empty circuit and arterial line filter decrease the number of gaseous emboli in the prime compared with a conventional circuit that contains air before being primed with fluid (92,93).…”

“…Most tcd systems utilize pulsed-wave ultrasound to detect cerebral emboli based on the measurement of the backscatter from the emboli. when microemboli are detected, brief transient increases in the ultrasonic signal are generated and recorded as HItS (33). the vast majority of published literature relating to embolus detection concerns tcd ultrasound in which a 1 MHz to 2 MHz probe is placed over the temporal lobe of the head in order to insonate the McA (34).…”