ABSTRACT
BACKGROUND: Currently, in the field of general anesthesia, balanced anesthesia in combination with analgesic, hypnotic, and muscle relaxant is commonly used. Remifentanil is the standard analgesic used in balanced anesthesia, and has contributed greatly to reduce the physical stress of the patient during surgery. We compared the stress response suppression effect of remifentanil by measuring stress hormones in 2 groups treated with different analgesic doses in orthopedic surgery using a tourniquet. METHODS: Twenty patients were randomly divided into 2 groups (10 patients each) undergoing maintenance of general anesthesia with 0.25 µg/kg/min remifentanil and sevoflurane (Group A) and 1.0 µg/kg/min remifentanil and sevoflurane (Group B). Hemodynamic changes, adrenocorticotropic hormone (ACTH), cortisol, antidiuretic hormone (ADH), adrenaline (Ad), noradrenaline (NAd), dopamine (DOA), insulin, and blood glucose were measured at the initiation of general anesthesia,10 minutes after the initiation of tourniquet application, and immediately before and 10 minutes after the completion of tourniquet application. RESULTS: ACTH, CORTISOL, ADH, AD, AND NAD LEVELS IN GROUP B WERE SIGNIFICANTLY LOWER (ACTH AND CORTISOL: P < 0.01, ADH, Ad, and NAd: P < 0.05) than those in Group A. No significant differences were noted in DOA, insulin, or blood glucose levels between the groups. CONCLUSION: Anesthesia management with high-dose remifentanil (1.0 µg/kg/min) suppressed intraoperative tourniquet pain-induced stress hormone release, suggesting its usefulness in stabilizing hemodynamics. TRIAL REGISTRATION: JMA-IIA00094.
ABSTRACT
PURPOSE: The hemodynamic profiles of KRN2391-induced hypotension have been reported to be a hyperdynamic state. However, the endocrine effects of KRN2391-induced hypotension remain to be elucidated. We investigated the endocrine and metabolic effects of KRN2391-induced hypotension on the plasma concentrations of catecholamines, aldosterone, cortisol, glucose, and lactic acid and on plasma renin activity. METHODS: Eight dogs were anesthetized with 087% halothane in oxygen. After a baseline period, mean arterial pressure (MAP) was lowered to 60 mmHg for 60min by the infusion of KRN2391. RESULTS: KRN2391-induced hypotension resulted in a 50% decrease (P<0.01) in MAP due to a 80% reduction (P<0.01) in systemic vascular resistance associated with a 224% increase (P<0.01) in cardiac index. Plasma norepinephrine concentrations increased (P<0.01) after 60 min of hypotension. Plasma epinephrine concentrations and plasma renin activity both increased (P<0.05) during the hypotensive period. Plasma aldosterone concentrations remained unchanged during the hypotensive period, but then increased (P<0.05) after termination of KRN2391. Plasma cortisol concentrations remained unchanged throughout the observation period. Plasma glucose concentrations increased (P<0.01) during the hypotensive period. Plasma lactic acid concentrations increased (P<0.01) throughout the observation period. CONCLUSION: KRN2391-induced hypotension activates the sympathetic nervous system and consequently may modulate the renin-angiotensin-aldosterone axis and carbohydrate metabolism.
