Blood in blood out 5 hour version plus#

Both esophageal and rectal temperatures were measured to the nearest 0.1вЊ with a YSI Model 46TUC temperature meter. The dogs were placed on a cooling blanket connected to a Blanketrol heater/cooler set to 0вЊ and covered with Ziploc bags of crushed ice. Hypothermia was initiated by surface cooling. During asanguineous perfusion, the animals were ventilated with intermittent deep sighs using a bag-valve device to prevent atelectasis. A rate of 12-18 respirations per minute, with an inspiration to expiration ratio of 1:3 and a tidal volume of 18 ml/kg, was used during initial induction of hypothermia respiratory rate and tidal volume were subsequently adjusted to maintain paO2 and paCO2 in the desired ranges during cooling and rewarming. The animals were intubated with cuffed endotracheal tubes and ventilated with a Harvard dual-phase control ventilator using room air. The animals were premedicated with 50 mg of chlorpromazine administered intramuscularly, and were anesthetized with 30 mg/kg of sodium pentobarbital (Nembutal) administered intravenously through an 18 ga Angiocath placed in the medial foreleg vein. Six mongrel dogs of both sexes, weighing from 22 to 27 kg, were fasted for 12 hours before the induction of anesthesia, but were allowed water ad lib. Six liters of perfusate were prepared the night before each experiment and stored on ice.ДЄll animals received humane care in compliance with the Principles of Laboratory Animal Care formulated by the National Society for Medical Research and the Guide for the Care and use of Laboratory Animals prepared by the National Institutes of Health (NIH Publication No. The composition of the perfusate used for total body washout is given in Table 1. The results reported here confirm this prediction and demonstrate for the first time that systemic hypothermia can be maintained for periods as long as 5 hours with consistently satisfactory recovery after warming. We felt that for the periods that are clinically pertinent for hypothermic surgery and related applications, a much simpler and considerably less expensive perfusate based on mannitol would be equally effective. Lactobionate, however, is required for 24-48 hour organ preservation, not for 2-6 hour preservation.

Blood in blood out 5 hour version plus#

In particular, a lactobionate-based perfusate has been shown to permit 2 hours of safe whole-body asanguineous hypothermia below 10вЊ, or one hour of cardiac arrest plus one hour of low-flow asanguineous perfusion (26, 27). Recent experiments strongly suggest that these difficulties stem from the same factors that limited clinical organ preservation prior to the development of solutions that precluded cell swelling during cold exposure. Clinical attempts to cool to lower temperatures to attain longer periods of safe circulatory arrest have been precluded by unacceptably high rates of respiratory, neurological, and hematological complications (1, 6, 17). However, the complexity of these procedures has been sharply limited by the relatively brief period during which circulatory arrest can be tolerated at 18вЊ. Hypothermia has provided extended periods of circulatory arrest for open-heart surgery (7, 21), aortic aneurysm repair (10), resection of renal cell carcinomas (19), and neurosurgical procedures (5). These results confirm the feasibility of applying the lessons learned from clinical organ preservation research to the problems of systemic hypothermia and support and extend recent reports of canine survival following hypothermia with lactobionate-based perfusates. All dogs survived without long-term sequelae. During warming, the asanguineous perfusate was replaced with blood and hemodialysis was instituted to normalize serum electrolytes. Perfusion continued for at least 4 hours at or below 9вЊ and for 2 hrs. The animals were then exsanguinated by perfusion with 4 L of a solution containing 210 mM mannitol and 35 mM KCl in place of NaCl as cooling continued to a rectal temperature of 4-5вЊ.

Dogs were placed on femoral-femoral bypass and supported with cardiopulmonary bypass during cooling to a rectal temperature of 10-12вЊ.

The purpose of this study was to test the hypothesis that a mannitol-based, potassium-enriched perfusate similar in concept to standard organ preservation solutions would be effective for prolonged whole body asanguineous hypothermia. This work was carried on from 1984 thru 1987