Comparison of wick and fibreoptic catheters in measurement of interstitial pressures in burned extremities.

We have performed simultaneous compartmental pressure monitoring in 14 burned extremities using both the established wick catheter and the recently developed fibreoptic catheter system. Initial pressures recorded by both systems correlated well. Discrepancies in subsequent values were considered to be either due to improper limb positioning or because of catheter damage or obstruction. Both systems are position sensitive, but the problem can be minimized by careful anchoring of the catheters. The fibreoptic catheter is more fragile, but the wick catheter, despite a constant slow infusion of heparinized fluid, is liable to obstruct. While it has proven difficult to compare cost-effectiveness for the two systems, it is our impression that the fibreoptic system offers advantages in terms of ease of placement and maintenance and long-term reliability of measurements. Experience from other burn groups with the two systems will be important. Finally, the parallel use of the two catheters emphasizes the potential fallibility of either system, and the necessity of applying clinical judgement in evaluating circumferentially burned extremities even though direct pressure monitoring is employed.