Quantification of intracompartmental pressure and volume under plaster casts.

UNLABELLED: Infusion lines (to elevate intracompartmental pressure experimentally) and wick catheters (to monitor the pressure produced) were inserted into hind-limb muscle compartments in twenty-six dogs. A padded plaster cast was then applied. The effect of the cast on intracompartmental pressure and volume and the effect of first splitting the cast and then cutting the padding were determined. Three different padding were used: dry Webril, Webril soaked in blood and Betadine (povidone-iodine), and Webril soaked in blood and Betadine and then dried. The cast was found to restrict expansion of the compartment volume by approximately 40 per cent. The most significant reductions in pressure in all groups occurred after the cast was cut and spread (mean reduction, 65 per cent). An additional pressure reduction of 10 to 20 per cent occurred after cutting the Webril. After removal of the cast, all limbs maintained some residual elevation of the intracompartmental pressure. CLINICAL RELEVANCE: This study demonstrates the need in clinical practice for continued evaluation and monitoring of a limb even after the cast has been completely removed because of signs and symptoms of a compartmental syndrome.