Background: Although there is general agreement as to the pathophysiology and treatment of compartment syndrome and the importance of intramuscular pressure measurements, there are many methods described to obtain these measurements. Variations in experimental measurements using current electronic monitoring, needle, and catheter devices of 18 to 22 mmHg are reported and are enough to cause errors in clinical decision-making that could result in significant clinical consequences. Current unacceptable reliability has been reported with the use of bevel-tipped needles and the clinical Whitesides technique. Because this is contrary to the authors' cumulative clinical and research experience with various methods when properly used (with the small required saline flush to assure a fluid continuum between tissue and the pressure monitor), this study was designed to clarify these problems. Although the two Whitesides techniques (original and clinical) are not in current use where digital methods are available, the clinical method is still used in the Third World.
Methods: To eliminate comparative errors, a laboratory compartment syndrome model was devised to allow simultaneous testing of different devices in the same area of fusiform muscle against increasing intramuscular pressure using the same transducer and monitor. Slit catheters, side-ported bevel-tipped needles, and 18-gauge bevel-tipped needles were compared against each other. The two Whitesides methods using a capillary meniscus and a mercury manometer were compared against a current electronic transducer method using identical 18-gauge bevel-tipped needles and varying diameter capillary tubing.
Results: The side-ported needle, slit catheter, and 18-gauge bevel-tipped needle were found to measure equivalent pressure when compared statistically with each other in pairs. The original Whitesides method using a 1.25-mm capillary tube and the digital transducer method using 18-gauge bevel-tipped needles was also found to measure equivalent pressure. The clinical Whitesides method using current plastic intravenous tubing of 3.0-mm internal diameter fails to produce an obvious capillary meniscus, leading to diminished reliability in the measured pressure.
Conclusions: The slit catheter, side-ported bevel-tipped needle, or an 18-gauge needle, when appropriately used with current electronic transducer monitoring, may be used clinically with confidence. When digital methods are not available, the original Whitesides method using 1.25-mm glass capillary tubing is an accurate alternative but requires preplanning. When only 3-mm tubing is available, this method is relatively useful when electronic means are not available by averaging several consecutive measurements.