The Comparison of the Effects of Different Doses of Levobupivacaine Infiltration on Wound Healing

[Effects of local anesthetics on wound healing]

INTRODUCTION

Local anesthetic infiltration is used widely for post-operative analgesia in many situations. However the effects of local anesthetics on wound healing are not demonstrated clearly. This study planned to evaluate the effects of lidocaine, prilocaine, bupivacaine and levobupivacaine on wound healing, primarily on wound tensile strength and on collagen ultrastructure.

METHODS

This study was conducted on male Sprague Dawley rats. On days 0, 8th, 15th, and 21st, all animals were weighed and received a preincisional subcutaneous infiltration of 3mL of a solution according the group. Control saline (C), lidocaine (L) 7mg.kg^-1, prilocaine (P) 2mg.kg^-1, bupivacaine (B) 2mg.kg^-1 and levobupivacaine (LVB) 2.5mg.kg^-1. The infiltrations were done at the back region 1.5cm where incision would be performed at the upper, middle and lower part along the midline, under general anesthesia. Wound tensile strengths were measured after 0.7cm×2cm of cutaneous and subcutaneous tissue samples were obtained vertical to incision from infiltrated regions. Tissue samples were also obtained for electron microscopic examination. Evaluations were on the 8th, 15th and 21st days after infiltration.

RESULTS

There was no difference between groups in the weights of the rats at the 0th, 8th, 15th and 21st days. The collagen maturation was no statistically different between groups at the 8th and 15th days. The maturation scores of the B and L groups at the 21st day was significantly lower than the Group C (1.40, 1.64 and 3.56; respectively). The wound tensile strength was no statistically different between groups at the 8th and 15th days but at the 21st day the Groups B and LVB had significantly lower value than Group C (5.42, 5.54 and 6.75; respectively).

CONCLUSION

Lidocaine and prilocaine do not affect wound healing and, bupivacaine and levobupivacaine affect negatively especially at the late period.

Beneficial effects of levobupivacaine regional anaesthesia on postoperative opioid induced hyperalgesia in diabetic mice

Background

Diabetic neuropathy is one of the most common complications of diabetes and causes various problems in daily life. The aim of this study was to assess the effect of regional anaesthesia on post surgery opioid induced hyperalgesia in diabetic and non-diabetic mice.

Methods

Diabetic and non-diabetic mice underwent plantar surgery. Levobupivacaine and sufentanil were used before surgery, for sciatic nerve block (regional anaesthesia) and analgesia, respectively. Diabetic and non-diabetic groups were each randomly assigned to three subgroups: control, no sufentanil and no levobupivacaine; sufentanil and no levobupivacaine; sufentanil and levobupivacaine. Three tests were used to assess pain behaviour: mechanical nociception; thermal nociception and guarding behaviours using a pain scale.

Results

Sufentanil, alone or in combination with levobupivacaine, produced antinociceptive effects shortly after administration. Subsequently, sufentanil induced hyperalgesia in diabetic and non-diabetic mice. Opioid-induced hyperalgesia was enhanced in diabetic mice. Levobupivacaine associated to sufentanil completely prevented hyperalgesia in both groups of mice.

Conclusion

The results suggest that regional anaesthesia can decrease opioid-induced hyperalgesia in diabetic as well as in non-diabetic mice. These observations may be clinically relevant for the management of diabetic patients.

The effect of gabapentin and pregabalin on intestinal incision wound healing in rabbits

AIM

To evaluate the macroscopic and histologic effects of pregabalin (PG) gabapentin (GB) on longitudinal intestinal wound healing in New Zealand rabbits.

MATERIALS AND METHODS

The animals were divided into three groups randomly; the control group (n=6), PG group (n=6) and GB group (n=6). All animals were premedicated with xylazine HCI, 5 mg/kg i.m. and general anaesthesia was performed by ketamine HCI 50 mg/kg i.m injection. A 4 cm incision in the caecum through median laparotomy was achieved under aseptic surgery. Intestinal wound was closed with double-sutured. All animals were received parenteral antibiotic treatment for 5 days. PG and GB groups were treated by PG (30 mg/kg, oral, daily) and GB (30 mg/kg, oral, daily) for 10 days respectively. Control group did not receive any treatment. The animals were euthanized on day 10 and the caecum was examined by laparotomy. Adhesion formation was observed, and tissue samples were taken from suture lines for histologic examination. Cellular infiltration (polymorphonuclear white blood cells and mononuclear cells), accumulation of connective tissue, vascularization and extent of necrosis were evaluated and scored separately for each of mucosal, submucosal, muscular and serosal layers of caecum.

RESULTS

Adhesions were more severe in the GB group compared to other groups. No statistically significant differences were detected among the three groups about the wound healing.

CONCLUSION

It was suggested that the use of gabapentinoids had no significant effect on wound healing in patients undergoing gastrointestinal surgery and further studies with treatment periods longer than 10 days are needed.

Comparison of the effects of bupivacaine, lidocaine, and tramadol infiltration on wound healing in rats

BACKGROUND AND OBJECTIVES

The aim of this study was to investigate the effects of saline solution, bupivacaine, lidocaine and tramadol infiltration on wound healing in rats.

METHOD

Thirty-two male Wistar Albino rats were randomly separated into four groups, receiving 3 mL saline solution in control group (Group C, n=8), 3 mL of 2% lidocaine in lidocaine group (Group L, n=8), 3 mL of 0.5% bupivacaine in bupivacaine group (Group B, n=8), and 3 mL of 5% tramadol in tramadol group (Group T, n=8). Breaking-strength measurements, collagen bundle counting, and histopathologic evaluation were evaluated in the tissue samples taken from the rats.

RESULTS

Comparing the control group with the groups where bupivacaine and lidocaine were used for wound infiltration, collagen production was lower, breaking-strength measurements showed reduced resistance while significantly high edema, vascularity, inflammation scores were found (p<0.0125). Between the control and the tramadol group there were no significant differences in collagen production, breaking-strength measurements, and edema, vascularity, inflammation scores (p>0.0125).

CONCLUSION

In our study, we found bupivacaine and lidocaine reduced the collagen production, wound breaking strength, and caused significantly high scores for edema, vascularity, and inflammation when compared to the control group. There was no significant difference between the control and the tramadol group. Results of this experimental preliminary study on rats support the idea that tramadol can be used for wound infiltration anesthesia without adverse effect on the surgical healing process. These results need to be verified in humans.

Effects of levobupivacaine on wound healing

BACKGROUND

Local anesthetic infiltration along the incision may be used to provide surgical anesthesia or postoperative analgesia. However, the effect of local anesthetics on wound healing remains controversial. In this investigation, we evaluated the effects of levobupivacaine on wound healing.

METHODS

Sixty Wistar albino female rats weighing 230±20 g were included, with 10 rats in each group: group early c (early control): 3 mL isotonic saline; group early l1.25 (early levobupivacaine 1.25): 1.25 mg/kg per 3 mL levobupivacaine; group early l2.5 (early levobupivacaine 2.5): 2.5 mg/kg per 3 mL levobupivacaine; group late c (late control): 3 mL isotonic saline; group late l1.25 (late levobupivacaine 1.25): 1.25 mg/kg per 3 mL levobupivacaine; and group late l2.5 (late levobupivacaine 2.5): 2.5 mg/kg per 3 mL levobupivacaine. Rats in groups early c to early l2.5 were euthanized on the 8th day. Rats in groups late c to late l2.5 were euthanized on the 21st day. Wound tension strength, tissue hydroxyproline, and fibrotic index levels of the tissue samples from the early c and early l2.5 and late c and late l2.5 groups, respectively, on the 8th and 21st days were examined.

RESULTS

Levobupivacaine decreased wound tension strength on the 8th day, especially a 2.5 mg/kg dose (P<0.001), and increased it on the 21st day (P<0.001). It also increased the inflammatory response (P<0.001) and collagen synthesis (8th day, P=0.109; 21st day, P=0.103) on both the 8th and 21st days.

CONCLUSIONS

While levobupivacaine had a positive effect on wound healing during the early period, negative effects were observed thereafter. Additional studies at the molecular level are necessary to determine the cause of these apparently opposite effects.

[Wound infiltration with local anesthetics for postoperative analgesia. Results of a national survey about its practice in France]

BACKGROUND AND OBJECTIVE

Local wound infiltration is a component of multimodal postoperative (p.o.) analgesia. Its implementation in current clinical practice remains unknown. Pain and Regional Anesthesia Committee of the French Anaesthesia and Intensive Care Society (Sfar) aimed to appraise its practice.

METHOD

Postal sample survey based on representative sample of national activity were sent to heads of anaesthesiology departments. The questionnaires included 36 items on single-shot and continuous wound infiltrations (CWI) with considerations about modality of administration, drugs and development limitations. Results in mean [CI95 %].

RESULTS

Response rate was 32 % (n=120). Sample was in accordance with national representation of health institutions. Local infiltration was included in 85 % [79-91] of the p.o. analgesia protocols. Regardless of the surgery, single-shot wound infiltration and CWI were used in more than 50 % of the patients by respectively 58 % [49-67] and 18 % [11-25] of the responders. However, a significant part of the surgeons remained reluctant to CWI. Lack of information and fear of septic complications were the most reported barriers. Peritoneal instillation after laparoscopy was rarely performed, in contrast with intra-articular infiltration after knee arthroscopy, performed systematically or very frequently by 60 % [50-70] of the responders.

CONCLUSION

The practice of local wound infiltration for p.o. analgesia seems presently well established, especially for single-shot injections. CWI is less commonly performed. Several surgical reluctances remain to be overcome. Better information about effectiveness and safety are likely to still improve their practices.

Clinically relevant doses of lidocaine and bupivacaine do not impair cutaneous wound healing in mice

BACKGROUND

Lidocaine and bupivacaine are commonly infiltrated into surgical cutaneous wounds to provide local anaesthesia after surgical procedures. However, very little is known about their effects on cutaneous wound healing. If an inhibitory effect is demonstrated, then the balance between the benefits of postoperative local anaesthesia and the negatives of impaired cutaneous wound healing may affect the decision to use local anaesthesia or not. Furthermore, if a difference in the rate of healing of lidocaine- and bupivacaine-treated cutaneous wounds is revealed, or if an inhibitory effect is found to be dose-dependent, then this may well influence the choice of agent and its concentration for clinical use.

METHODS

Immediately before incisional wounding, we administered lidocaine and bupivacaine intradermally to adult female mice, some of which had been ovariectomized to act as a model of post-menopausal women (like post-menopausal women, ovariectomized mice heal wounds poorly, with increased proteolysis and inflammation). Day 3 wound tissue was analysed histologically and tested for expression of inflammatory and proteolytic factors.

RESULTS

On day 3 post-wounding, wound areas and extent of re-epithelialization were comparable between the control and local anaesthetic-treated animals, in both intact and ovariectomized groups. Both tested drugs significantly increased wound activity of the degradative enzyme matrix metalloproteinase-2 relative to controls, while lidocaine also increased wound neutrophil numbers.

CONCLUSIONS

Although lidocaine and bupivacaine influenced local inflammatory and proteolytic factors, they did not impair the rate of healing in either of two well-established models (mimicking normal human wound healing and impaired age-related healing).