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Summary Introduction Methods Results Discussion Evidence to support intra‐operative lidocaine infusion regimens in patients with obesity is lacking, risking underdosing or toxicity. We aimed to measure the plasma concentrations of lidocaine and its active metabolites to develop a pharmacokinetic model and optimised dosing regimen in patients with obesity.A standardised weight‐based intravenous lidocaine regimen was administered to patients with a BMI ≥ 30 kg.m‐2 undergoing elective laparoscopic abdominal surgery. Using lean body weight, a 1.5 mg.kg‐1 loading dose over 10 min and infusion of 1.5 mg.kg‐1.h‐1 was administered intra‐operatively. Arterial blood was sampled during and after the infusion. The total and unbound plasma concentrations of lidocaine, monoethylglycinexylidide and glycinexylidide were measured using liquid chromatography‐mass spectrometry. Monolix was used for population pharmacokinetic analysis. Dosing simulations were performed using Simulx to develop a regimen that best targeted a therapeutic plasma concentration between 2.5 and 5 μg.ml‐1.Thirty patients provided 221 plasma samples (median (IQR [range]) age 51 (44–61 [32–76]) y and 21 female). Median (IQR [range]) total body weight was 107.0 (91.8–132.5 [80.0–189.0]) kg and BMI was 37.7 (33.6–46.5 [30.2–58.4]) kg.m‐2. Using total and unbound plasma concentrations of lidocaine, monoethylglycinexylidide and glycinexylidide, a four‐compartment model was developed. Unbound lidocaine volume of distribution was 2.1 l.kg‐1 and clearance 1.7 l.kg‐1.h‐1. Simulations showed that doses used currently had a low probability of target attainment of 0%. A loading dose of 2 mg.kg‐1 over 20 min followed by an infusion of 3 mg.kg‐1.h‐1 based on lean body weight improved probability of target attainment to 18.6%. The infusion should be reduced to 2 mg.kg‐1.h‐1 after 80 min.Our simulated dosing regimen achieved therapeutic concentrations more successfully in patients with obesity. Further studies should evaluate the clinical safety and efficacy of this dosing regimen. [ABSTRACT FROM AUTHOR]

A retrospective audit at Prince of Wales Hospital and Sydney Children's Hospital evaluated the impact of implementing a preoperative team huddle in theatre settings. The study found that the team huddle led to increased frequency of full multidisciplinary attendance, improving awareness, communication, and efficiency among staff. While there was a slight decrease in staff attitudes towards safety and teamwork, the team huddle was well-received and positively impacted theatre operations. The report, authored by a diverse group of individuals, emphasizes the importance of effective communication and teamwork in enhancing perioperative care. [Extracted from the article]

The coronavirus disease 2019 (COVID-19) pandemic in Australia resulted in significant additional infection control precautions for consumers and the health workforce. Prior to widespread vaccine availability, substantial changes were made to the operating theatre management of patients presenting for surgery with suspected or diagnosed COVID-19. This study aimed to calculate the actual costs of operating theatre care for patients with confirmed or suspected COVID-19. Data were prospectively collected for all patients presenting for surgery with confirmed or suspected COVID-19 at the Royal Brisbane and Women's Hospital. Information collected included patient characteristics, surgical and anaesthesia details, equipment, theatre utilisation, staffing and cleaning. The associated variable costs and usual costs of care were calculated according to the Australian National Efficient Price. We compared estimated usual costs with those estimated for patients with confirmed or suspected COVID-19. Twenty-four patients with suspected COVID-19 infection underwent surgery between May 2020 and February 2021. Cost analysis revealed a mean (standard deviation (SD), range) increase in costs of providing perioperative care for COVID-19 suspect patients of A$2252 (A$2570, A$315.85–10,398); that is, a mean of 207.5% more than usual care costs. This was primarily due to the increased number of staff and time required to complete these cases with appropriate infection control. [ABSTRACT FROM AUTHOR]

• Plasma protein binding affects free drug concentrations. • Lidocaine is a lipophilic local anaesthetic that is highly protein-bound. • In the presence of propofol, lidocaine protein-binding was unchanged. • In vitro unbound lidocaine concentrations were unchanged in the presence of propofol. Intravenous lidocaine is increasingly used as an analgesic adjunct during general anaesthesia. Lidocaine is highly protein-bound and changes to binding can alter drug efficacy or toxicity. We aimed to measure the effect of various propofol and lidocaine plasma concentration combinations on the protein binding and concentration of lidocaine in vitro. Known targeted concentrations of propofol and lidocaine were added to drug-free human plasma in vitro. Samples were prepared and analysed in various clinically relevant concentration combinations; propofol at 0, 2, 4 and 6 µg/mL, and lidocaine at 1, 3 and 5 µg/mL. The total and unbound concentrations of lidocaine were measured by ultra-high performance liquid chromatography-mass spectrometry and percentage protein binding was determined. Data were presented as mean and standard deviation (SD) and differences between groups analysed. The overall mean protein binding of lidocaine was 68.8% (SD 5.5, range 57.5–80.9%). Beta regression analysis revealed no statistically significant difference in lidocaine percentage binding across a range of propofol and lidocaine concentration combinations. Propofol did not alter the unbound and free pharmacologically active proportion of lidocaine at different clinically targeted concentrations of propofol and lidocaine in plasma in vitro. The percentage of plasma protein binding of lidocaine in this study was consistent with previously published results. [ABSTRACT FROM AUTHOR]

Objective: In patients with obesity, it was determined what proportion had an arm slant angle (SA) < 83° and which measure best predicted arm conicity. Patient experience with noninvasive blood pressure measurement was evaluated.Methods: Arm SA was calculated from arm measurements. Linear regression determined whether BMI, weight, or right midarm circumference (MAC) best predicted conicity. Patient experiences were evaluated by survey and conventional content analysis of free-text comments.Results: One hundred participants had a median (interquartile range; range) BMI of 44.1 (39.1-53.1; 31.1-80.8). Thirty-three (33%) had a right arm SA < 83°. Seven (7%) had a right MAC outside the recommended range. BMI, weight, and the right MAC showed low correlation with and explained little of the variation (with age and sex adjustment) in right arm SA (r = -0.29, -0.27, -0.31; P = 0.003, 0.007, 0.002; R2  = 0.09, 0.08, 0.10). Forty-two (42%) reported noninvasive blood pressure measurement caused severe pain, and 30 (30%) reported skin damage. Themes identified in free-text responses were "problems with equipment," "feelings and experiences," and "concerns about accuracy."Conclusions: Current equipment is inadequate for patients with obesity based on MAC and conicity. Pain and skin damage contributed to negative experiences of these patients. [ABSTRACT FROM AUTHOR]