Bladder Temperature Research Articles

Low Dose Protamine for Heparin Reversal in 40 Consecutive Cardiopulmonary Bypass Patients

(J. Extra-Corpor. Technol. 19[3] p. 348-351 Fall 1987, 13 ref.) Reversal of systemic heparinization in cardiac surgery has been a subject of controversy for some time. For reversal, protamine sulfate (PS) is given in as high a dose as 2:1. We heparinize our patients with 2.0 mg./kg. of beef lung heparin and reverse this with 70% of the total heparin dose. The mean preoperative activated clotting time (ACT) was 148 seconds. The mean ACT on cardiopulmonary bypass (CPB) was 446 seconds. After successfully weaning the patients from CPB at a bladder temperature of 37°C or greater, the 70% dose of PS was given resulting in a mean ACT of 134 seconds post bypass. The mean post-operative blood loss was 695cc (230cc-3120cc) with only 32% (13 patients) requiring platelet administration and 22% (9 patients) requiring fresh frozen plasma (FFP). No patient required re-operation for hemorrhage. There were 33 coronary artery bypass grafts, all of which were on aspirin and persantine, four aortic valve replacements and three atrial septal defects. These data strongly suggest that heparin reversal can be obtained with low dose PS when these patients are weaned from CPB at 37°C bladder temperature.

Sweating, hemodynamic responses, and thermal equilibration during hyperthermia in humans.

Hyperthermia, to 42 degrees C, for treatment of cancer, was induced 23 times in 13 anesthetized patients utilizing an extracorporeal heat-exchange circuit. Sweating rate over the chest, abdomen, arm and forearm ranged from 0.2 to 0.9 mg sweat X min-1 X cm-2. Cardiac index (CI), stroke volume index (SVI), left ventricular stroke work index, and right ventricular stroke work index initially increased to 221 +/- 12.5, 162 +/- 9.6, 142 +/- 11, and 203 +/- 29% but later fell to 169-173, 113-120, 69, and 148-117% of control, respectively. Heart rate initially rose to 145 +/- 5.9% and then stabilized at 160-162% of control. Pulmonary arterial occlusion pressure and central venous pressure initially fell to 82 +/- 8 and 93 +/- 9% but later rose to 87-102 and 105-120% of control levels, respectively. The hemodynamic response to severe heat stress in anesthetized humans was characterized by peripheral vasodilation accompanied by compensatory increases in heart rate and CI. Ventricular function, as reflected by SVI and CI, declined with continued heat stress, despite reduced afterload and stable or increased filling pressures. Pulmonary arterial temperature rose fastest, followed by the esophageal, rectal, and bladder temperatures, respectively. Jugular bulb temperature also rose rapidly.

Urinary bladder temperature monitoring: a new index of body core temperature.

A new method of core body temperature monitoring is introduced and compared to currently used methods. A close correlation exists between urinary bladder temperatures and each of the techniques studied. The correlation is good when compared to esophageal and rectal temperature and best when compared to pulmonary arterial blood temperature. During rapid rewarming after extracorporeal circulation, the urine temperature consistently increases faster than rectal or esophageal and seemingly is a better measure of blood temperature rather than muscle mass temperature. Urine temperature monitoring is reliable, safe, convenient, and accurate for routine intraoperative and postoperative continuous use in adult patients with urethral catheterization.

Thermal Control Dynamics of a Dairy Cow Obtained by Pulse Testing

ABSTRACT ANON-LACTATING Holstein cow-was subjected to pulse changes in environmental air temperature, and bladder, tympanic and skin tempera-tures, carbon dioxide production and total water vapor loss were measured. Impulse testing techniques were applied to the transient responses of the animal's skin and core tempera-ture to evaluate the thermoregulatory system in the frequency domain. Results indicated impulse test methods could be used to evaluate an animal's thermo control system. Analysis of two tests suggested that the animal used feed forward control coupled with feed back control for regulation of body core temperature. Skin temperature response to changing air temperature would be similar to a first order system for frequencies up to 0.37 cycles/hr.

Tunnel paved with concrete blocks

Since hyperthermia selectively kills lung cancer cells, we developed a venovenous perfusion-induced systemic hyperthermia system for advanced lung cancer therapy. Our objective was to test the safety and accuracy of our venovenous perfusion-induced systemic hyperthermia system in 5-day sheep survival studies, following Good Laboratory Practice standards.Our venovenous perfusion-induced systemic hyperthermia system, which included a double-lumen cannula (Avalon Elite, Rancho Dominguez, Calif), a centrifugal pump (Bio-Pump 560; Medtronic Inc, Minneapolis, Minn), a heat exchanger (BIOtherm; Medtronic Perfusion Systems, Brooklyn Park, Minn), and a heater/cooler (modified Blanketrol IIIl Cincinnati Subzero, Cincinnati, Ohio), was tested in healthy adult sheep (n = 5). The perfusion circuit was primed with prewarmed Plasma-Lyte A (Baxter Healthcare Corp, Deerfield, Ill) and de-aired. Calibrated temperature probes were placed in the right and left sides of the nasopharynx, bladder, and blood in/out tubing in the animal. The double-lumen cannula was inserted through the jugular vein into the superior vena cava, with the tip in the inferior vena cava.Therapeutic core temperature (42°C-42.5°C), calculated from the right and left sides of the nasopharynx and bladder temperatures, was achieved in all sheep. Heating time was 21 ± 5 minutes. Therapeutic core temperature was maintained for 120 minutes followed by a cooling phase (35 ± 6 minutes) to reach baseline temperature. All sheep recovered from anesthesia with spontaneous breathing within 4 hours. Arterial, pulmonary, and central venous pressures were stable. Transient increases in heart rate, cardiac output, and blood glucose occurred during hyperthermia but returned to normal range after venovenous perfusion-induced systemic hyperthermia termination. Electrolytes, complete blood counts, and metabolism enzymes were within normal to near normal range throughout the study. No significant venovenous perfusion-induced systemic hyperthermia–related hemolysis was observed. Neurologic assessment showed normal brain function all 5 days.Our venovenous perfusion-induced systemic hyperthermia system safely delivered the hyperthermia dose with no significant hyperthermia-related complications.