Here we report on the development of a selective and sensitive high-performance liquid chromatographic method for the determination of lidocaine in human serum. The extraction of lidocaine and procainamide (internal standard) from serum (0.25 mL) was achieved using diethyl ether under alkaline conditions. After liquid–liquid extraction, the separation of analytes was accomplished using reverse phase extraction. The mobile phase, a combination of acetonitrile and monobasic potassium phosphate, was pumped isocratically through a C18 analytical column. The ultraviolet (UV) wavelength was at 277 nm for the internal standard, and subsequently changed to 210 for lidocaine. The assay exhibited excellent linearity (r2 > 0.999) in peak response over the concentration ranges of 50–5000 ng/mL lidocaine HCl in human serum. The mean absolute recoveries for 50 and 1000 ng/mL lidocaine HCl in serum using the present extraction procedure were 93.9 and 80.42%, respectively. The intra- and inter-day coefficients of variation in the serum were <15% at the lowest, and <12% at other concentrations, and the percent error values were less than 9%. The method displayed a high caliber of sensitivity and selectivity for monitoring therapeutic concentrations of lidocaine in human serum.

Objectives Rectus sheath blocks are an established option for analgesia following abdominal surgery, but pharmacokinetic data are limited. This study sought to characterise the absorption of lidocaine injectate and the pharmacokinetics of lidocaine after rectus sheath injection. Methods Bilateral rectus sheath single‐injection blocks were given to 10 patients undergoing general or urological surgery. Afterwards, serial lidocaine serum levels and ultrasound measurements of the rectus sheath injectate reservoir were collected. Key findings Injectate within the rectus sheath was visible with ultrasound up to 12 h after injection. However, the rate of drug absorption exceeded that of injectate disappearance. Peak serum concentration occurred within 30 min with average peak concentrations of 1.65 μg/ml. Lidocaine clearance was lower than reported in young healthy subjects. The body mass index positively correlated with lidocaine terminal phase half‐life, and clearance negatively correlated with age. Conclusions The study provides the first data describing lidocaine pharmacokinetics after rectus sheath injection. Peak serum concentrations transiently achieved systemic levels associated with pain relief after a single bolus injection. The data from this study could be used to develop a regime using single shot rectus sheath blockade with a bolus of lidocaine followed by infusion using bilateral rectus sheath catheters.

Bariatric patients are difficult to assess clinically for signs of postoperative complication. Diagnostic laparoscopy (DL) is used to investigate patients suspicious for complications such as anastomotic leak (AL) and intra-abdominal hemorrhage (IH). Most bariatric surgeons use DL in the presence of sustained tachycardia; however, the rate of this procedure and its clinical value have not been sufficiently investigated.A retrospective review of patients undergoing bariatric surgery from January 2010 to December 2011 was performed. Data from 4 collaborative bariatric centres of excellence were included in this analysis. From among all elective bariatric procedures, cases that required early reoperation were selected for further evaluation.A total of 1001 elective bariatric procedures were identified. Of these, 952 (95%) were primary bariatric procedures, including 866 (91%) Roux-en-Y gastric bypasses and 86 (9%) sleeve gastrectomies. The remaining 48 cases represented revisional proced ures. Of these, 11 patients (1.1%) returned to the operating room within 72 hours for DL: 64% were primary cases (n = 7) and 36% revisional cases (n = 4). Intraoperative findings included AL (45%, n = 5), IH (27%, n = 3), no pathology identified (18%, n = 2) and small bowel obstruction (9%, n = 1). Of the 9 patients with complications, all were tachycardic (heart rate > 100 beats/min), and 4 of the 5 patients with AL were febrile (t > 37.5). There were no reported adverse events directly related to the use of DL.Diagnostic laparoscopy is a useful and safe option for both the diagnosis and treatment of suspected complications after bariatric surgery. The majority of patients returning to operating room had significant findings, and all were treated laparoscopically. Persistent postoperative tachycardia or fever were highly predictive of positive findings during DL. An emphasis on early decisionmaking and expeditious return to the operating room for laparoscopy should be the standard for bariatric patients on clinical suspicion of a postoperative complication. 4Changes of active and total ghrelin, GLP-1 and PYY following restrictive bariatric surgery and their impact on satiety: comparison of sleeve gastrectomy and adjustable gastric banding. A

Orthostatic convulsive syncope is defined as a decrease in cerebral blood supply resulting in convulsive, seizure-like symptoms. The authors present the first case report of orthostatic convulsive syncope in a burn patient. There are many causes of transient loss of consciousness in patients. An algorithm is presented to aid in the workup and management strategies for this diagnosis. This approach in conjunction with a neurology consult should add in the assessment and treatment of transient loss of consciousness and orthostatic convulsive syncope in a burn patient.