Effect of remifentanil infusion rate on stress response in orthopedic surgery using a tourniquet application

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.

Keywords: Remifentanil; Stress response; Tourniquet pain.

Figures

Figure 1

Anesthetic protocol. *Case of hemodynamic suppression (bradycardia, hypotension). - systolic blood pressure (SBP) 80 mmHG continued for 1 min: administration of phenylephrine 0.1 mg or ephedrine 8 mg. - Heart rate (HR) 40 beats/min continued for 1 min: administration of atropine 0.5 mg. * Case in stress response (tachycardia, hypertension). - administration of remifentanil 1 μg/kg bolus (0.1 mL per 10 kg body weight). LOC, loss of consciousness. INTB, tracheal intubation. IV-PCA, intravenous patient controlled analgesia.

Figure 2

Changes in mean arterial blood pressure (MAP), and heart rate (HR). Data are expressed as the mean ± standard deviation. Changes from the baseline (ANES start) values were different (* P < 0.05, ** P < 0.01) between the groups using unpaired t-test. Mean value was different (# P < 0.05, ## P < 0.01) than at baseline within the same group using dunnett test. ANES start: Just before drug consumption for induction of anesthesia. TA: Tourniquet application.

Figure 3

Changes in adrenocorticotropic hormone (ACTH), cortisol, and antidiuretic hormone (ADH). Data are expressed as the mean ± standard deviation. Changes from the baseline (ANES start) values were different (* P < 0.05, ** P < 0.01) between the groups using unpaired t-test. Mean value was different (# P < 0.05, ## P < 0.01) than at baseline within the same group using dunnett test. ANES start: Just before drug consumption for induction of anesthesia. TA: Tourniquet application. Standard value: ACTH (7.2-63.3 pg/mL), cortisol (4.5-21.1 pg/mL), ADH (0.3-3.5 pg/mL).

Figure 4

Changes in adrenaline (Ad), noradrenaline (NAd), and dopamine (DOA). Data are expressed as the mean ± standard deviation. Changes from the baseline (ANES start) values were different (* P < 0.05, ** P < 0.01) between the groups using unpaired t-test. Mean value was different (# P < 0.05, ## P < 0.01) than at baseline within the same group using dunnett test. ANES start: Just before drug consumption for induction of anesthesia. TA: Tourniquet application. Standard value: Ad (<100 pg/mL), NAd (140–450 pg/mL), DOA (< 20 pg/mL).

Figure 5

Changes in insulin and blood glucose. Data are expressed as the mean ± standard deviation. Changes from the baseline (ANES start) values were different (* P < 0.05, ** P < 0.01) between the groups using unpaired t-test. Mean value was different (# P < 0.05, ## P < 0.01) than at baseline within the same group using dunnett test. ANES start: Just before drug consumption for induction of anesthesia. TA: Tourniquet application. Standard value: insulin (2.2-12.4 pg/mL), blood glucose (70–109 mg/dL).