Effect of an air-fluidized bed on insensible water loss.

Air-fluidized beds are increasingly used for patients with burns, decubitus ulcers, trauma, and generalized debility. Fluidized beds provide a medium that is more dense than water for patients to float on by pumping air through silicone-coated microspheres separated from the patient by a monofilament polyester sheet. A continuous stream of warm air flowing across the patient increases insensible evaporative water loss and may lead to dehydration. The air-fluidized bed has a wide range of operating temperatures (82 degrees to 102 degrees F), but surprisingly few data are available on the amount of water loss at different bed temperatures. This lack of information is probably secondary to difficulties in obtaining accurate fluid balance measurements in patients. Our objective was to construct a nomogram of insensible water loss for the fluidized bed using healthy volunteers under controlled conditions. We then prospectively compared this nomogram to data obtained from hospitalized patients.

Hemodynamic and metabolic effects of exercise in Crotalaria-induced pulmonary hypertension in rats.

The hemodynamic and metabolic effects of exercise were measured in Crotalaria-induced pulmonary hypertension in rats. The Crotalaria group had increased preexercise heart rate, mean pulmonary arterial pressure (PAP), arteriovenous O2 content difference, right ventricular work index (RVWI), and total pulmonary vascular resistance index (TPVRI) and decreased mean systemic blood pressure (BP), arterial O2 content (CaO2), venous O2 content (CvO2), cardiac index (CI), stroke volume index (SVI), and left ventricular work index (LVWI). The Crotalaria group during exercise had increased PAP, RVWI, TPVRI, and total systemic vascular resistance index and decreased BP, O2 consumption, CaO2, CvO2, CI, SVI, LVWI, O2 pulse index, and exercise duration. It is hypothesized that abnormal right ventricular function was a primary factor in the reduced exercise tolerance of the Crotalaria group.