Improvement in postoperative pain control by combined use of intravenous dexamethasone with intravenous dexmedetomidine after interscalene brachial plexus block for arthroscopic shoulder surgery: A randomised controlled trial.

BACKGROUND: Intravenous dexamethasone or dexmedetomidine is reported to prolong the duration of analgesia after single-shot interscalene brachial plexus block (ISBPB). However, the effect of co-administration of these agents on the duration of analgesia has not been evaluated. OBJECTIVES: We evaluated the difference in time to first rescue analgesic request between patients receiving co-administered intravenous dexamethasone and dexmedetomidine and patients receiving intravenous dexamethasone alone after single-shot ISBPB for arthroscopic shoulder surgery. DESIGN: A randomised controlled study. SETTING: A single tertiary care centre, study period from August 2017 to January 2018. PATIENTS: Sixty-six patients undergoing arthroscopic shoulder surgery with ISBPB with 15 ml of 0.5% ropivacaine with 1 : 200 000 epinephrine. INTERVENTIONS: We randomly assigned the patients to one of three groups: intravenous 0.9% saline (control), intravenous dexamethasone 0.11 mg kg (D1 group), or co-administered intravenous dexamethasone 0.11 mg kg and intravenous dexmedetomidine 1.0 µg kg (D2 group). MAIN OUTCOME MEASURES: The primary outcome was the time to first rescue analgesic request. RESULTS: The median [interquartile range] time to first rescue analgesic request was significantly longer for the D2 group (66.3 h [23.3 to 72]) than the D1 (17.4 h [14.9 to 36], P = 0.002) and control (10.9 h [10.1 to 12.2], P < 0.001) groups. The D1 and D2 groups both had reduced pain scores, reduced postoperative opioid consumption, less sleep disruption and improved patient satisfaction compared with the control group. There were no significant elevations in blood glucose concentrations in patients receiving dexamethasone (D1 and D2 groups) compared with the control group at postoperative day 1. CONCLUSION: Co-administration of intravenous dexamethasone (0.11 mg kg) with dexmedetomidine (1.0 µg kg) significantly prolonged the time to first rescue analgesic request after single-shot ISBPB in patients undergoing arthroscopic shoulder surgery. TRIAL REGISTRATION: Clinical Trial Registry of Korea; https://cris.nih.go.kr/cris/index.jsp and identifier: KCT0002569.

Clonidine premedication prevents preoperative hypokalemia.

STUDY OBJECTIVE: To test the hypothesis that clonidine premedication could prevent an increase of plasma epinephrine occurring as a result of anxiety, and a decrease of the serum potassium (K+) levels before the induction of anesthesia. DESIGN: Randomized, double-blinded study. SETTING: University Hospital of Seoul. PATIENTS: 44 ASA physical status I and II patients, aged 20 to 50 years, scheduled for knee, ear, or nose surgery. INTERVENTION: 44 patients were randomly allocated into one of two groups: 22 patients (clonidine group) received clonidine 300 microg orally at 120 minutes before the induction of anesthesia. The other 22 patients (control group) received a placebo. MEASUREMENTS AND MAIN RESULTS: Anxiety level, serum K+, and plasma epinephrine were measured at an outpatient clinic, and immediately before the induction of anesthesia. There were no differences between groups in degree of anxiety experienced, serum K+, or plasma epinephrine levels as measured at the out-patient clinic. Immediately before the induction of anesthesia, the serum K+ levels of the clonidine group were higher than those of the control group (3.89 +/- 0.26 mEq/L vs. 3.50 +/- 0.36 mEq/L), and anxiety and plasma epinephrine levels of clonidine group were lower than those of the control group (p < 0.05). The frequency of hypokalemia (K+ < or = 3.5 mEq/L) of the clonidine group immediately before the induction of anesthesia was significantly lower than that of the control group (0% vs. 50%). CONCLUSIONS: Clonidine premedication was effective in preventing hypokalemic episodes occurring before the induction of anesthesia.