Acta anaesthesiologica Scandinavica
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Acta Anaesthesiol Scand · Aug 1987
Randomized Controlled Trial Clinical TrialPostoperative ventilatory and circulatory effects of heating after aortocoronary bypass surgery. Postoperative external heat supply.
The effects of postoperative external heat supply on shivering, oxygen uptake, carbon dioxide production, ventilatory requirements and haemodynamic variables were studied postoperatively after aortocoronary bypass surgery in 24 men with stable angina pectoris. After hypothermic cardiopulmonary bypass (CPB) at 25 degrees C, the patients were rewarmed to a nasopharyngeal temperature of at least 38 degrees C, resulting in a rectal temperature of about 34 degrees C before termination of CPB. Twelve patients, forming the control group, were given no other external heat supply. ⋯ Shivering, oxygen uptake, CO2 production and ventilation volumes were significantly reduced compared with the control group. Cardiac index and stroke index were higher and systemic oxygen extraction was lower in the radiant heat supply group. Postoperative hypertension and vasoconstriction were greatly decreased, suggesting that residual hypothermia is an important cause of the postoperative vasoconstriction.
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Acta Anaesthesiol Scand · Aug 1987
Thoracolumbar epidural anaesthesia blocks the circulatory response to laryngoscopy and intubation.
Laryngoscopy and endotracheal intubation cause a stress reaction resulting in an increase in heart rate and systemic blood pressure. This haemodynamic response is considered to be due to a sympathetic discharge caused by stimulation of the upper respiratory tract. This stress reaction during laryngoscopy and endotracheal intubation was studied in patients with total thoracolumbar epidural anaesthesia (EDA). ⋯ The epidural anaesthesia caused a reduction of the mean arterial blood pressure (MAP) by 25%, and a reduction of the heart rate (HR) by 7%, but neither the induction with thiopentone nor the laryngoscopy and intubation caused any changes in mean arterial blood pressure or heart rate. However, in the control group MAP increased 29% and HR 16% following intubation. Thus, the T1-L2 epidural anaesthesia with 2% mepivacaine with adrenaline blocked the blood pressure reaction to laryngoscopy and intubation, and consequently the efferent sympathetic nervous system was completely blocked.
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Acta Anaesthesiol Scand · Aug 1987
Randomized Controlled Trial Clinical TrialPostoperative ventilatory and circulatory effects of heating after aortocoronary bypass surgery. Extended rewarming during cardiopulmonary bypass and postoperative radiant heat supply.
Twenty-four patients with stable angina pectoris were studied after aortocoronary bypass surgery with hypothermic cardiopulmonary bypass (CPB). Twelve patients (radiant heat supply group) were rewarmed during CPB to a nasopharyngeal temperature of at least 38 degrees C and a mean rectal temperature of 34.4 degrees C. Postoperatively they received radiant heat supply from a thermal ceiling. ⋯ The combination of extended rewarming during CPB and postoperative radiant heat supply significantly reduced oxygen uptake, carbon dioxide production and the required ventilation volumes during early recovery as compared with the values in the radiant heat supply group. The reduced metabolic demands were accompanied by lower cardiac index and oxygen delivery, which, however, were sufficient for adequate tissue perfusion as judged by the similarity in oxygen extraction and arterial base excess values in the two groups. The metabolic demands and ventilatory requirements were reduced to a level at which safe early extubation is possible.