Peri-operative continuation of metformin does not improve glycaemic control in patients with type 2 diabetes: A randomized controlled trial.

Historically, metformin was withheld before surgery for fear of metformin-associated lactic acidosis. Currently, however, this risk is deemed to be low and guidelines have moved towards the continuation of metformin. We hypothesized that continuing metformin peri-operatively would lower postoperative serum glucose level without an effect on plasma lactate levels. We performed a single-blind multicentre randomized controlled trial in people with type 2 diabetes mellitus scheduled for non-cardiac surgery and continued (MF+ group) or withheld (MF- group) metformin before surgery. The main outcome measures were the differences in peri-operative plasma glucose and lactate levels. We randomized 70 patients (37 MF+ group and 33 MF- group) with type 2 diabetes mellitus. Postoperative glucose levels were similar in the MF+ and the MF- groups (8.2 ± 1.8 vs 8.3 ± 2.3 mmol/L P = .95) Although preoperative lactate levels were slightly higher in the MF+ group compared with the MF- group (1.5 vs 1.2 mmol/L; P = .02), the postoperative lactate levels were not significantly different (1.2 vs 1.0 mmol/L; P = .18). In conclusion, continuation of metformin during elective non-cardiac surgery does not improve glucose control or raise lactate levels to a clinically relevant degree.

Perioperative pain management in hip arthroscopy; what options are there?

Hip arthroscopy is a fast growing orthopedic field of expertise. As in any field of surgery adequate postoperative pain management regimes are of utmost importance. The purpose of this review is to provide an overview of current knowledge on anesthetic options for perioperative pain management for hip arthroscopy. We searched the Pubmed/Medline and Embase database for literature and included 10 studies for our analysis. Because of the variety of pain scales and different ways of measured pain no meta-analysis could be performed and a descriptive review is performed. There are several types of pain regimens that can mostly be divided in two groups: local anesthetics and nerve blocks. Included studies show a rather large variation in reported visual analogue scale scores, post anesthesia care unit admission time and opioid usage. There are several anesthetic options available for hip arthroscopy. Different studies use different dosages, anesthetic regimens and different protocols; this partly explains the differences between studies with similar techniques. Peripheral nerve blocks seems promising but regarding current literature no clear recommendation can be made about what the best perioperative pain management option is, an overview of all reported techniques is given.