Efficacy of topical atorvastatin-loaded emulgel and nano-emulgel 1% on post-laparotomy pain and wound healing: A randomized double-blind placebo-controlled clinical trial

This study aimed to develop atorvastatin-loaded emulgel and nano-emulgel dosage forms and investigate their efficiency on surgical wound healing and reducing post-operative pain. This double-blind randomized clinical trial was conducted in a surgical ward of a tertiary care hospital affiliated with university of medical sciences. The eligible patients were adults aged 18 years or older who were undergoing laparotomy. The participants were randomized in a 1:1:1 ratio to one of three following groups of atorvastatin-loaded emulgel 1% (n = 20), atorvastatin-loaded nano-emulgel 1% (n = 20), and placebo emulgel (n = 20) twice a day for 14 days. The primary outcome was the Redness, Edema, Ecchymosis, Discharge, and Approximation (REEDA) scores to determine the rate of wound healing. The Visual Analogue Scale (VAS) and quality of life were the secondary outcomes of this study. A total of 241 patients assessed for eligibility; of them, 60 patients completed the study and considered for final evaluation. A significant decrease in REEDA score was observed on Days 7 (63%) and 14 (93%) of treatment with atorvastatin nano-emulgel (p-value < 0.001). A significant decrease of 57% and 89% in REEDA score was reported at Days 7 and 14, respectively, in atorvastatin the emulgel group (p-value < 0.001). Reduction in pain VAS in the atorvastatin nano-emulgel was also recorded at Days 7 and 14 of the intervention. The results of the present study suggested that both topical atorvastatin-loaded emulgel and nano-emulgel 1% were effective in acceleration of wound healing and alleviation of pain of laparotomy surgical wounds, without causing intolerable side effects.

Burrowing behavior as an indicator of post-laparotomy pain in mice

Detection of persistent pain of a mild-to-moderate degree in laboratory mice is difficult because mice do not show unambiguous symptoms of pain or suffering using standard methods of short-term observational or clinical monitoring. This study investigated the potential use of burrowing performance - a spontaneous and highly motivated behavior - as a measure of post-operative pain in laboratory mice. The influence of minor surgery on burrowing was investigated in adult C57BL/6J mice of both genders in a modified rodent burrowing test (displacement of food pellets from a pellet-filled tube) within the animal's home cage. Almost all (98%) healthy mice burrowed (mean latency 1.3 h, SEM 0.5 h). After surgery without pain treatment, latency of burrowing was significantly prolonged (mean Δ latency 10 h). Analgesic treatment using the anti-inflammatory drug carprofen (5 mg/kg bodyweight) decreased latency of burrowing after surgery (mean Δ latency 5.5 h) to the level found in mice that had been anesthetized (mean Δ latency 5.4 h) or had received anesthesia and analgesia (mean Δ latency 4.6 h). Analgesia during surgery was associated with a significantly earlier onset of burrowing compared to surgery without pain treatment. A distinct gradation in burrowing performance was found ranging from the undisturbed pre-operative status to the intermediate level following anesthesia/analgesia and surgery with analgesia, to the pronounced prolongation of latency to burrow after surgery without pain relief. In conclusion, post-surgical impairment of general condition, probably mainly attributable to pain, can be conveniently assessed in laboratory mice on the basis of the burrowing test.