Platelet Function and Coagulability during Cardiopulmonary Bypass in Children: Analysis by Sonoclot with a Heparinase Glass-Beads Cuvette

 [2003 SPA/JSPA Joint Meeting SR16]

Platelet Function and Coagulability during Cardiopulmonary Bypass in Children: Analysis by Sonoclot with a Heparinase Glass-Beads Cuvette.

Y. Toyoshima, A. Kimura, M. Nawa, S. Kawana

Departments of Anesthesiology, Hokkaido Children’s Hospital and Medical Center

 

Introduction: It has been difficult to evaluate platelet function during cardiopulmonary bypass (CPB) due to the effect of heparin. Sonoclot analysis with a heparinase glass-beads cuvette enables bedside monitoring of platelet function and coagulability in heparinized blood. In this preliminary study, we measured platelet function and coagulability during CPB in children with congenital heart disease (CHD).

 

Methods: Approval for the study was obtained from our institutions review board, and informed consent was obtained from the parents of the children. The subjects were five children with CHD (1.2-4.5 yrs old) who were scheduled to undergo cardiac surgery under CPB. Blood samples were withdrawn from an arterial catheter. Measured parameters were platelet count and the following parameters for Sonoclot analysis: Sonoclot activated clotting time (s-ACT), clot rate (CR), time to peak amplitude (TP) and angle of the peak. S-ACT is the time until onset of fibrin formation and the end of the liquid phase. CR reflects the rate of fibrin formation and amount of available fibrinogen. TP and angle of the peak, which reflect clot retraction away from the surface of the probe, are indicators of platelet function. Sampling points were (a) after induction of anesthesia, (b) 10 min after the start of CPB, (c) termination of CPB and (d) 1 hr after termination of CPB.

 

Results: Average values of measurements are shown in the table.

s-ACT(sec)	CR	TP(min)		angle(°)	PLT(×103/mm2)
(a)	225.8±42.22	16.2±3.70	12.2±3.96	80.6±41.06	327.6±125.69
(b)	245.0±15.81	14.1±4.98	14.7±6.32	83.8±31.55	213.4±99.59
(c)	219.0±11.25	16.0±3.78	14.3±5.89	56.6±19.36	170.0±85.74
(d)	225.2±24.08	15.1±6.88	18.8±9.65	106.6±42.89	114.8±79.91

 

Discussion and conclusion: Our results clearly showed changes in platelet function and coagulability during CPB. Although basic characteristics must be elucidated, Sonoclot analysis with a heparinase glass-beads cuvette is useful for monitoring platelet function and coagulability in pediatric cardiac surgery.