Factors influencing the occurrence of thrombophlebitis after post-surgical long-term intravenous catheterization of colic horses: a study of 38 cases.

Thrombophlebitis is a well-known complication of the use of long-term in-dwelling catheters. In humans, catheter material has been shown to strongly influence the occurrence of thrombophlebitis. In the horse, the influence of catheter material has been studied in healthy experimental animals, but information on the relative importance of this factor is lacking. To investigate which factors have most impact on the frequency of jugular vein thrombosis in post-surgical colic horses, a clinical study was performed on 38 animals. Horses were randomly divided into two groups. In one group a polytetrafluoroethylene catheter was used, in the other a polyurethane catheter. Both groups were clinically monitored and screened for signs of thrombophlebitis. Seven out of 38 horses developed thrombophlebitis. The type of catheter material used had no influence on thrombophlebitis development. Dwell time was significantly longer in horses that developed thrombophlebitis compared with those that did not. There was no relationship between the occurrence of thrombophlebitis and underlying disease or surgical treatment, suggesting that the general state of debilitation these horses experienced was the most important determinant for the development of thrombophlebiris. This was further stressed by the fact that seven horses developed thrombophlebitis of the contralateral vein that had been used for the induction of anaesthesia (this incidence is much higher than in horses anaesthetized for elective surgery). It is concluded that the state of debilitation is the most important determining factor for the occurrence of thrombophlebitis after the use of long-term in-dwelling intravenous catheters. This makes a substantial reduction of the incidence of thrombophlebitis difficult, but some progress can be made by consequently restricting dwell time.