The effect of water temperature on hand volume during volumetric measurement using the water displacement method.

This study evaluated the effect of water temperature on hand volume during volumetric measurement using the water displacement method. Four volumetric measurements were taken for 24 normal subjects using four different water temperatures--5 degrees C (41 degrees F), 20 degrees C (68 degrees F), 35 degrees C (95 degrees F), and 45 degrees C (113 degrees F). Between volumetric measurements the skin temperature of the hand was allowed to return to baseline levels using an Orion biofeedback unit. In comparing the two extreme temperatures, the average change in hand volume was +5.8 milliliters (ml), which represented a deviation of 1.4% of the mean (coefficient of variation). In using a t-test to determine significance, it was found that the change in volume between these two temperatures was significant at the 0.01 level. In comparing the two moderate temperatures, the average change in hand volume was +1.9 ml, representing a deviation of 0.5% of the mean, with no statistical significance. For research purposes, this study suggests the need to control for water temperature when using a volumeter to measure hand edema. For general clinical practice, however, the use of "cool" or "tepid" water does not appear to alter hand volume readings significantly to be of concern.