A multistate Kalman filter for neonatal clotting time prediction and earlydetection of coagulation disturbances

The multistate Kalman filter was applied to develop a heparin dose proposal system and to detect coagulation disturbances during neonatal extracorpore al membrane oxygenation (ECMO). A system containing this filter was based o n the activated clotting time (ACT) values and the heparin doses administer ed every hour during ECMO. If the ACT value can be predicted accurately fro m the previous heparin dose, a heparin dose proposal can be given to achiev e or maintain the required ACT level. The analysis was done on 6,356 ACT le vel measurements in 44 ECMO neonates. The multistate Kalman filter techniqu e showed an unbiased prediction of ACT, with a standard deviation of 23 sec onds. Two out of three cases of disseminated intravascular coagulation (DIC ) were detected. ACT values were predicted sufficiently accurately by the m ultistate Kalman filter technique to justify a prospective study on the per formance of the heparin dose proposal system and its ability to detect DIG.