The Effect of Perioperative Vitamin C on Postoperative Analgesic Consumption: A Meta-Analysis of Randomized Controlled Trials

Abstract

Because the analgesic effect of vitamin C against acute pain remains poorly addressed, this meta-analysis aimed at investigating its effectiveness against acute postoperative pain. A total of seven randomized controlled trials with placebo/normal controls were identified from PubMed, Cochrane Library, Medline, Google Scholar, and Embase databases. Pooled analysis showed a lower pain score (standardized mean difference (SMD) = −0.68, 95% CI: −1.01 to −0.36, p < 0.0001; I2 = 57%) and a lower morphine consumption (weighted mean difference (WMD) = −2.44 mg, 95% CI: −4.03 to −0.86, p = 0.003; I2 = 52%) in the vitamin group than that in the placebo group within postoperative 1–2 h. At postoperative 24 h, a lower pain score (SMD = −0.65, 95% CI: −1.11 to −0.19, p = 0.005; I2 = 81%) and lower morphine consumption (WMD = −6.74 mg, 95% CI: −9.63 to −3.84, p < 0.00001; I2 = 85%) were also noted in the vitamin group. Subgroup analyses demonstrated significant reductions in pain severity and morphine requirement immediately (1–2 h) and 24 h after surgery for patients receiving intravenous vitamin C but not in the oral subgroup. These findings showed significant reductions in pain score and opioid requirement up to postoperative 24 h, respectively, suggesting the effectiveness of perioperative vitamin C use. Further large-scale trials are warranted to elucidate its optimal intravenous dosage and effectiveness against chronic pain in the postoperative pain control setting.

Preclinical study in a postoperative pain model to investigate the action of ketamine, lidocaine, and ascorbic acid in reversing fentanyl-induced, non–glutamate-dependent hyperalgesia

“…It also seems to modulate glutamatergic transmission and blocks the NMDA receptors through altering the redox changes on the NMDA receptor. [10][11][12][13][14][15][16][17][18][19][20] Hung et al 10 attributed the antinociceptive effect of ascorbic acid to its antioxidant and neuromodulatory properties and its role as a free radical scavenger. However, in this work, the acute and subcutaneous administration of ascorbic acid was not able to inhibit mechanical allodynia and thermal hyperalgesia produced by fentanyl.…”

Analgesic efficacy and risk of low-to-medium dose intrathecal morphine in patients undergoing cardiac surgery: An updated meta-analysis

“…For the current study, visual analog scale (VAS) 0–10 cm or 0–100 mm, numerical rating scale (NRS) 0–10, and visual numeric scale (VNS) 0–10 were converted into VAS 0–10 cm for pain severity comparison ( 22 ). Regarding the comparison of opioid dosage across different studies, we converted all opioid dosages to morphine equivalents as previously described ( 23 ). We assessed heterogeneity with I 2 statistics and defined substantial heterogeneity as an I 2 over 50%.…”

Vitamin C—Sources, Physiological Role, Kinetics, Deficiency, Use, Toxicity, and Determination

“…Vitamin C is frequently added to oral preparations containing iron in order to increase iron absorption [ 5 , 154 ]. In a recent meta-analysis, patients who received intravenous vitamin C perioperatively had significant pain reduction and decreased morphine requirements [ 204 ].…”