Kasner M, Grosse J, Krebs M, Kaczmarczyk G
Clinic of Anesthesiology and Operative Intensive Medicine, Universitätsklinikum Rudolf Virchow, Free University of Berlin, Germany.
Anesthesiology. 1995 Jun;82(6):1396-405. doi: 10.1097/00000542-199506000-00011.
Anesthetic agents influence central regulations. This study investigated the effects of methohexital anesthesia on renal and hormonal responses to acute sodium and water loading in dogs in the absence of surgical stress.
Fourteen experiments (two in each dog) were performed in seven well-trained, chronically tracheotomized beagle dogs kept in highly standardized environmental and dietary conditions (2.5 mmol sodium and 91 ml water/kg body weight daily). Experiments lasted 3 h, while the dogs were conscious (7 experiments) or, after 1 h control, while they were anesthetized (7 experiments) with methohexital (initial dose 6.6 mg/kg body weight and maintenance infusion 0.34 mg.min-1.kg-1 body weight) over a period of 2 h. In both experiments, extracellular volume expansion was performed by intravenous infusion of a balanced isoosmolar electrolyte solution (0.5 ml.min-1.kg-1 body weight). Normal arterial blood gases were maintained by controlled mechanical ventilation. In another five dogs the same protocol was used, and vasopressin (0.05 mU.min-1.kg-1 body weight) was infused intravenously during methohexital anesthesia.
Values are given as means. During methohexital anesthesia, mean arterial pressure decreased from 108 to 101 mmHg, and heart rate increased from 95 to 146 beats/min. Renal sodium excretion decreased; urine volume increased; and urine osmolarity decreased from 233 to 155 mosm/l, whereas plasma osmolarity increased from 301 to 312 mosm/l because of an increase in plasma sodium concentration from 148 to 154 mmol/l. Plasma renin activity, plasma aldosterone concentration, plasma atrial natriuretic peptide, and plasma antidiuretic hormone concentrations (range 1.8-2.8 pg/ml) did not change in either protocol. In the presence of exogenous vasopressin (antidiuretic hormone 3.3 pg/ml), water diuresis did not occur, and neither plasma osmolarity nor the plasma concentration of sodium changed.
Methohexital may impair osmoregulation by inhibiting adequate pituitary antidiuretic hormone release in response to an osmotic challenge.
麻醉剂会影响中枢调节。本研究在无手术应激的情况下，探究了甲己炔巴比妥麻醉对犬急性钠水负荷时肾脏及激素反应的影响。
在7只训练有素、长期行气管切开术的比格犬身上进行了14项实验（每只犬进行2项），这些犬饲养于高度标准化的环境和饮食条件下（每日2.5 mmol钠和91 ml水/千克体重）。实验持续3小时，其中7项实验中犬处于清醒状态，另外7项实验中，在1小时的对照期后，用甲己炔巴比妥（初始剂量6.6 mg/千克体重，维持输注0.34 mg·min⁻¹·kg⁻¹体重）麻醉犬2小时。在两项实验中，均通过静脉输注平衡等渗电解质溶液（0.5 ml·min⁻¹·kg⁻¹体重）来进行细胞外液扩容。通过控制机械通气维持正常动脉血气。在另外5只犬中采用相同方案，在甲己炔巴比妥麻醉期间静脉输注血管加压素（0.05 mU·min⁻¹·kg⁻¹体重）。
数据以平均值表示。在甲己炔巴比妥麻醉期间，平均动脉压从108 mmHg降至101 mmHg，心率从95次/分钟增至146次/分钟。肾钠排泄减少；尿量增加；尿渗透压从233 mosm/l降至155 mosm/l，而血浆渗透压从301 mosm/l增至312 mosm/l，这是由于血浆钠浓度从148 mmol/l增至154 mmol/l。两种方案中，血浆肾素活性、血浆醛固酮浓度、血浆心钠素和血浆抗利尿激素浓度（范围1.8 - 2.8 pg/ml）均未改变。在存在外源性血管加压素（抗利尿激素3.3 pg/ml）的情况下，未出现水利尿，血浆渗透压和血浆钠浓度均未改变。
甲己炔巴比妥可能通过抑制垂体在渗透压刺激下释放足够的抗利尿激素而损害渗透压调节。
