Intraoperative core temperature depends on both distribution of heat within the body and in system heat balance. During the first hour of anesthesia core to peripheral redistribution of heat is the primary cause of core hypothermia. Subsequently, however, hypothermia results from heat loss exceeding heat production. Core temperature during this phase therefore depends on system heat balance. Because anesthetics profoundly impair thermoregulatory control factors that increase thermogenesis or reduce loss of heat to the environment, they moderate the rate at which intraoperative hypothermia develops.
Little attention has been paid to prevent the development of anesthesia-induced hypothermia by stimulating the generation of heat.
This present study was designed to evaluate the ability of amino acids infusion to prevent anesthesia induced hypothermia and postoperative shivering in patients receiving general anesthesia.
The study included 80 patients, who were randomly allocated into 2 groups, each one subdivided into two groups:
Group I: 40 patients (under general anesthesia): subdivided into two groups Group Ia: composed of 20 patients who received amino acids intravenously infusion. Group Ib: composed of 20 patients who received corresponding volumes of nutrient-free saline solution intravenously infused.
Group II: 40 patients (under spinal anesthesia) Subdivided into two groups:
Group IIa: this group was composed of 20 patients who received amino acids intravenously infusion. Group IIb (control group): this group was composed of 20 patients who received corresponding volumes of nutrient-free saline solution intravenously infused.
Routine vital signs monitoring of heart rate, blood pressure, oxygen saturation, end tidal CO2 and ECG was continuously displayed.
Core body temperature was continuously monitored via rectal thermistor probe, Surface (skin) temperature was monitored; Monitoring was started just before amino acids infusion (base line), and then continuously performed for six hours started just before the induction of anesthesia. Arterial blood gases and pH analysis, serum cortical, serum glucose and serum lactate was done every 30 min. starting just before the starting of amino acids infusion till six hours from the induction of anesthesia.
All patients were assessed every 30 min in the first 2 hours c Pain at rest was scored on the visual analogue scale (VAS).
The study revealed that preoperative amino acids infusion decreased significantly the magnitude of anesthesia induced hypothermia and enhanced the rate od recovery from it.
It was found that infusion of amino acids before the anesthesia significantly recovered anesthesia induced hypothermia.
The rate of postoperative shivering was significantly reducing in amino acids treated groups. Hypothermia induced postoperative adverse effects as hypertention and shivering associated increased postoperative pain and hypoventilation were significantly reduced by the infusion of amino acids.
Arterial blood gases, pH analysis, serum glucose, serum cortical and serum lactate were nearly comparable in the studied groups, suggesting that the amino acids infusion did not produce uncompensated metabolic or respiratory stress for patients receiving it.
It can be concluded that amino acids infusions restor cor body temperature and almost eliminated postoperative shivering.
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