Adjunctive dexamethasone palmitate use for intercostal nerve block after video-assisted thoracoscopic surgery: A prospective, randomized control trial

Abstract

Objectives: The efficacy of dexamethasone palmitate in extending durations of local anesthetic blocks is uncertain. In a randomized, double-blind study of patients undergoing video-assisted thoracoscopic surgery, we tested whether intravenous or perineural dexamethasone palmitate caused prolonged analgesia after intercostal nerve block.

Methods: A total of 90 patients subjected to video-assisted thoracoscopic surgery between May and December 2022 were randomly assigned to one of three intercostal nerve blocks study arms (n = 30 each), requiring the addition of 0.5% ropivacaine (23 ml) as follows: controls (C group), 2 ml saline; IV-DXP group, 2 ml saline + 2 ml (8 mg) intravenous dexamethasone palmitate; and PN-DXP group, 2 ml (8 mg) perineural dexamethasone palmitate. Time to first postoperative remedial analgesia served as primary outcome measure. Secondary endpoints included postoperative opioid consumption, pain scores by Visual Analog Scale, analgesia satisfaction, and related adverse effects.

Results: Compared with controls or the IV-DXP group, time to first postoperative remedial analgesia was longer and postoperative opioid consumption for rescue analgesia was lower in the PN-DXP group (p < 0.01). Similarly, the Visual Analog Scale scores in patients at 8, 12, 18, and 24 h postoperatively were lower in the PN-DXP group than in controls and the IV-DXP group (p < 0.01). Patient satisfaction was statistically lower in the PN-DXP group, compared with either the control or IV-DXP group (p < 0.05). Clinically, the three groups did not differ significantly in occurrences of adverse effects during the 48-h postoperative monitoring period (p > 0.05).

Conclusions: Perineural dexamethasone palmitate is a promising adjunct to ropivacaine intercostal nerve block by prolonging analgesia with almost no related adverse effects.

Keywords: Anesthesia; Dexamethasone palmitate; Intercostal nerve block; Postoperative analgesia; Video-assisted thoracoscopic surgery.

Fig. 1

CONSORT flow diagram of participant enrollment, allocation, follow-up and analysis Abbreviations: CONSORT, Consolidated Standards of Reporting Trials.

Fig. 2

Kaplan-Meier plots of times to first analgesic request. The times to first analgesic request showed a significant difference in relation to time. ^#P < 0.05 between IV-DXP and C group. *p < 0.01 between PN-DXP and C group. ^&p < 0.01 between PN-DXP and IV-DXP group.

Fig. 3

Postoperative opioid consumption at different times in each group. In all groups, the opioid consumption (MME) showed a significant difference in relation to time. *p < 0.01 between PN-DXP and C group. ^&p < 0.01 between PN-DXP and IV-DXP group.Abbreviations: MME, morphine milligram equivalent.

Fig. 4

Postoperative VAS scoring at different times in each group. A. VAS scoring at rest and coughing; B. VAS scoring at coughing. In all groups, the VAS score showed a significant difference in relation to time. VAS (0–10, 0 = no pain, 10 = unbearable pain). ^#p < 0.05 between IV-DXP and C group; *p < 0.01 between PN-DXP and C group; ^&p < 0.01 between PN-DXP and IV-DXP group.

Fig. 5

Postoperative blood glucose concentrations at different times in each group. In all groups, the blood glucose concentrations showed a significant difference in relation to time. ^#p < 0.05 between IV-DXP and C group; *p < 0.05 between PN-DXP and C group; ^&p < 0.01 between PN-DXP and IV-DXP group.