Drop In Core Body Temperature Research Articles

Guidelines for Prevention and Management of Complications Following Kidney Transplantation in Rats

Kidney transplantation in rats is a useful model for microsurgery, transplantation, and immunology studies. Our aim was to analyze various techniques of kidney transplantation in rats with emphasis on guidelines for the prevention and management of complications. Complications were categorized into general, vascular, and urological types and respectively attributed to long transplantation time, core body temperature drop, nonreplaced intraoperative blood loss, anastomosis failure, and ureteral anastomoses with stents or cannulas, which increase the risk of calculus formation. In conclusion, to decrease the complication rates the animal should be placed on a heating pad. For hemodynamic stability NaCl should be administered subcutaneously. To reduce the risk of thrombosis, ice-cold saline containing heparin should be administered. Vascular complications, which mainly depend on the microsurgeon’s expertise, can be prevented by meticulous surgical technique (preferably an end-in-end anastomosis). The main urinary complications can be minimized by avoiding stents and cannulas and focusing on using techniques like the bladder-patch technique.

Acute and phase-shifting effects of ocular and extraocular light in human circadian physiology.

Light can influence physiology and performance of humans in two distinct ways. It can acutely change the level of physiological and behavioral parameters, and it can induce a phase shift in the circadian oscillators underlying variations in these levels. Until recently, both effects were thought to require retinal light perception. This view was challenged by Campbell and Murphy, who showed significant phase shifts in core body temperature and melatonin using an extraocular stimulus. Their study employed popliteal skin illumination and exclusively considered phase-shifting effects. In this paper, the authors explore both acute effects and phase-shifting effects of ocular as well as extraocular light. Twelve healthy males participated in a within-subject design and received all of three light conditions--(1) dim ocular light/no light to the knee, (2) dim ocular light/bright extraocular light to the knee, and (3) bright ocular light/no light to the knee--on separate nights in random order. The protocol consisted of an adaptation night followed by a 26-h period of sustained wakefulness, during which a 4-h light pulse was presented at a time when maximal phase delays were expected. The authors found neither immediate nor phase-shifting effects of extraocular light exposure on melatonin, core body temperature (CBT), or sleepiness. Ocular bright-light exposure reduced the nocturnal circadian drop in CBT, suppressed melatonin, and reduced sleepiness significantly. In addition, the 4-h ocular light pulse delayed the CBT rhythm by -55 min compared to the drift of the CBT rhythm in dim light. The melatonin rhythm shifted by -113 min, which differed significantly from the drift in the melatonin rhythm in the dim-light condition (-26 min). The failure to find immediate or phase-shifting effects in response to extraocular light in a within-subjects design in which effects of ocular bright light are confirmed strengthens the doubts raised by other labs of the impact of extraocular light on the human circadian system.

Comparison of Traditional Thermal Support Devices With the Forced-Air Warmer System in Anesthetized Hispaniolan Amazon Parrots (Amazona ventralis)

Active warming of birds under general anesthesia is required to prevent hypothermia and its life-threatening consequences. The ability of a forced-air warming system to provide thermal homeostasis during isoflurane anesthesia of 10 Hispaniolan Amazon parrots (Amazona ventralis) was compared to a circulating-water blanket and an infrared heat emitter. Each bird was anesthetized once weekly for a 60-minute trial of each of 5 methods: no thermal support (control), surgical drape only, towel-covered circulating-water blanket and drape, infrared heat emitter and drape, and forced-air warmer and drape. An esophageal thermometer was used to measure the bird's core body temperature during each trial, and the temperature of the surgical area immediately adjacent to the bird as well as the ambient room temperature were also recorded. Time zero was 5 minutes after intubation. None of the warming methods prevented a significant decrease in core body temperature measured during the 60-minute trial period. A significant decrease in core body temperature was observed within 15 minutes with all warming methods except the forced-air warmer, which prevented a significant decrease in temperature before 30 minutes. Even though the forced-air warmer did not prevent a drop in core body temperature during the last 30 minutes of the trial, the temperature remained within the clinically acceptable range of 38.3–40.6°C. A significant increase occurred in the temperature of the surgical area immediately adjacent to each bird from 15 to 60 minutes for all warming methods, but the magnitude of the increase was not different among modalities. The forced-air warming system proved superior to traditional heating methods in restricting heat loss and is an effective modality for the prevention of hypothermia during isoflurane anesthesia of Hispaniolan Amazon parrots in clinical practice or a research setting.

Measurement of CO 2 hypothermia during laparoscopy and pelviscopy: How cold it gets and how to prevent it

To evaluate intraabdominal CO(2) temperature during a variety of standard operative laparoscopy procedures with different insufflators (BEI Medical, Snowden & Pencer, Storz Laparoflator, Storz Endoflator, Wolf) and devices to maintain body temperature (Bair Hugger, fluid warmer, Blanketrol blankets). Prospective, nonrandomized study (Canadian Task Force classification II-1). Community hospital in rural Alabama. Sixty-two consecutive patients (53 women, 9 men; average age 56.8 yrs, range 21-94 yrs). Patients underwent standard laparoscopic and pelviscopic procedures during which intraoperative temperature changes in the insufflation system, abdomen, and rectum were measured. Carbon dioxide was at room temperature in the insufflation hose ( approximately 23 degrees C). During insufflation, intraabdominal gas temperature decreased to as much as 27.7 degrees C (average 32.7 degrees C) depending on length of operation (23 min-5 hrs 8 min), amount of gas used (12.8-801 L), gas flow (up to 20 L/min), and leakage rate. Preoperative and postoperative temperature comparisons showed no decline in rectal temperature (average +0.18 degrees C) because warming equipment was sufficient. The decrease in intraoperative intraabdominal gas temperature is remarkable and can potentially harm the patient. It can be limited by restricting gas flow and leakage. In operations longer than 1 hour, substantial core body temperature drop should be prevented with appropriate heating and hydration devices. An insufflator with internal gas heating (Snowden & Pencer) had no significant clinical effect. (J Am Assoc Gynecol Laparosc 6(3):289-295, 1999)

Body temperature and the activity-stress ulcer in the rat

Rats which develop lesions after exposure to the activity-stress procedure show a drop in core body temperature. Body temperature and running activity are inversely related, thereby suggesting that excessive running is an attempt at behavioral thermoregulation. However, the restricted feeding schedule does not provide sufficient energy to support the high running activity. Rats placed in a cold environment (7°C) and fed only 1 hr daily also develop stomach lesions but not as extensive as rats housed in activity wheel cages and also fed 1 hr daily. These results suggest that the activity-stress procedure is a high energy demand situation and that subsequent stomach lesions represent a disturbance in energy metabolism.

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Study Objective. To evaluate intraabdominal CO2 temperature during a variety of standard operative laparoscopy procedures with different insufflators (BEI Medical, Snowden & Pencer, Storz Laparoflator, Storz Endoflator, Wolf) and devices to maintain body temperature (Bair Hugger, fluid warmer, Blanketrol blankets).Design. Prospective, nonrandomized study (Canadian Task Force classification II-1).Setting. Community hospital in rural Alabma.Patients. Sixty-two consecutive patients (53 women, 9 men; average age 56.8 yrs, range 21–94 yrs).Interventions. Patients underwent standard laparoscopic and pelviscopic procedures during which intraoperative temperature changes in the insufflation system, abdomen, and rectum were measured.Measurements and Main Results. Carbon dioxide was at room temperature in the insufflation hose (≈23°C). During insufflation, intraabdominal gas temperature decreased to as much as 27.7°C (average 32.7°C) depending on length of operation (23 min-5 hrs 8 min), amount of gas used (12.8–801 L), gas flow (up to 20 L/min), and leakage rate. Preoperative and postoperative temperature comparisons showed no decline in rectal temperature (average +0.18°C) because warming equipment was sufficient.Conclusion. The decrease in intraoperative intraabdominal gas temperature is remarkable and can potentially harm the patient. It can be limited by restricting gas flow and leakage. In operations longer than 1 hour, substantial core body temperature drop should be prevented with appropriate heating and hydration devices. An insufflator with internal gas heating (Snowden & Pencer) had no significant clinical effect.