Pharmacokinetics of levobupivacaine with epinephrine in transversus abdominis plane block for postoperative analgesia after Caesarean section.

BACKGROUND: Transversus abdominis plane block is increasingly used for post-Caesarean section analgesia. Cases of toxicity and the limited pharmacokinetic information during pregnancy motivated this study. The objective of the study was to characterise and compare the pharmacokinetics of levobupivacaine with epinephrine in tranversus abdominis plane block, in post-Caesarean section patients and healthy volunteers. METHODS: After approval by the Ethics Committee, we collected data from 12 healthy parturients after elective Caesarean section (Study 1) and data from 11 healthy male volunteers from a previous study (Study 2). Transversus abdominus plane block was performed under ultrasound guidance. The following injectates were used: levobupivacaine 0.25%, 20 ml with epinephrine 5 µg ml-1 (Study 1) per side; 20 ml of the same solution (unilateral block) (study 2). The plasma venous concentration of levobupivacaine was measured serially for 90 min. Pharmacokinetic parameters (volume of distribution, clearance, and absorption half-life) were estimated using a non-linear mixed effects model (NONMEM). Simulation in 1000 patients estimated the maximum concentration and the time to reach it after bilateral transversus abdominis plane block. RESULTS: Venous concentrations were below toxic levels (2.62 mg L-1). Levobupivacaine volume of distribution after Caesarean section was higher than in healthy volunteers [172 L (70 kg)-1 (95% confidence interval: 137-207) vs 94.3 L (70 kg)-1 (95% CI: 62-128); P<0.01]. Clearance and absorption half-life were similar. The simulation showed that maximum levobupivacaine concentration is lower and occurs later in postpartum patients (P<0.01). Postoperative analgesia was effective. CONCLUSIONS: Postpartum women reached relatively low plasma concentrations of levobupivacaine after transversus abdominal plane block given a volume of distribution 80% higher than volunteers, which could confer a greater margin of safety. CLINICAL TRIAL REGISTRATION: NCT02852720.

Simulation-based training program with deliberate practice for ultrasound-guided jugular central venous catheter placement.

BACKGROUND: Current evidence supports the utility of simulation training for bedside procedures such as ultrasound-guided jugular central venous catheter (CVC) insertion. However, a standardized methodology to teach procedural skills has not been determined yet. The aim of this study was to evaluate the effectiveness of a simulation-based training program for improving novice technical performance during ultrasound-guided internal jugular CVC placement. METHODS: Postgraduate year 1 (PGY-1) residents from anesthesiology, emergency medicine, cardiology, ICU, and nephrology specialties were trained in four deliberate practice sessions. Learning objectives included principles of ultrasound (US), preparation (gown, glove, draping), procedural skills I (US scanning and puncture), and procedural skills II (catheter insertion). CVC technical proficiency was tested pre- and post-training using hand-motion analysis with the Imperial College Surgical Assessment Device (ICSAD) and a global rating scale (GRS). RESULTS: Thirty-five PGY-1 residents successfully completed the program. These novices' GRS scores improved significantly after the training (P < 0.001). Total path length measured with the ICSAD decreased significantly after the training (P = 0.008). Procedural time decreased significantly after training from 387 (310-501) seconds to 200 (157-261) seconds (median and interquartile range) (P = 0.029). CONCLUSION: This simulation-training program based on deliberate practice significantly increased the technical skills of residents in US-guided short-axis, out-of-plane internal jugular CVC placement. Data also confirm the validity of the ICSAD as an assessment tool for ultrasound-guided internal jugular CVC placement learning.

Current practice in regional anaesthesia in South America: An online survey. / Práctica actual de la anestesia regional en América del Sur: encuesta en línea.

OBJECTIVE: A survey was conducted in order to obtain a profile of the practice of regional anesthesia in South America, and determine the limitations of its use. METHODS: After institutional ethics committee approval, a link to an online questionnaire was sent by e-mail to anaesthesiologists in Argentina, Bolivia, Chile, Colombia, Panamá, Paraguay, Perú, and Uruguay. The questionnaire was processed anonymously. RESULTS: A total of 1,260 completed questionnaires were received. The results showed that 97.6% of the anaesthesiologists that responded used regional anaesthesia in clinical practice, 66.9% performed peripheral nerve block (PNB) regularly, 21.6% used continuous PNB techniques, and 4.6% used stimulating catheters. The primary source of training was residency programs. As regards PNB, the most common performed were interscalene (52.3%), axillary (45.1%), femoral (43.2%), and ankle block (43%). As regards the localisation technique employed, 16% used paraesthesia, 44.2% used a peripheral nerve stimulator, and 18.1% ultrasound guidance. CONCLUSIONS: Regional anaesthesia and PNB are commonly used among South American anaesthesiologists. Considering that each country has its own profile for use, this profile should guide training in clinical practice, especially in residency programs.

[Bringing clinical simulation into an Anesthesia residency training program in a university hospital. Participants' acceptability assessment]. / Inserción de la simulación clínica en el currículum de Anestesiología en un hospital universitario. Evaluación de la aceptabilidad de los participantes.

INTRODUCTION: Clinical simulation is currently an integral part of the curriculum of the Anesthesiology residency programs in other countries. We aimed to describe and evaluate the insertion of simulation in an anesthesia residency training program. METHODS: Activities feasible to be used for training in a simulated environment were classified into 2 modules: workshops for technical skills conducted with first year residents, and high fidelity simulation scenarios performed with second and third year residents. After each activity, and using an anonymous questionnaire, residents assessed their satisfaction and objectives accomplished. RESULTS: A total of 18 activities: 6 skills workshops and 12 high fidelity scenarios were assessed. A total of 206 questionnaires were analyzed, corresponding to 41 residents. Almost all (96%) of respondents agreed or strongly agreed that workshops met the objectives and should be mandatory in the anesthesia curriculum; however, 11% agreed that the activity caused anxiety and/or nervousness. The high fidelity scenarios were considered realistic and consistent with the objectives by 97% of residents, and 42% felt that workshops caused anxiety and/or nervousness. CONCLUSIONS: The inclusion of simulation has been well accepted by the residents. The activities have been described as realistic, and limited to the objectives, essential points in adult education, as according to Kolb's learning model this is associated with profound, useful and long lasting knowledge.

Evaluation of the effect of intravenous lidocaine on propofol requirements during total intravenous anaesthesia as measured by bispectral index.

BACKGROUND: I.V. lidocaine is increasingly used as an adjuvant during general anaesthesia. The aim of this study was to evaluate the effect of i.v. lidocaine in reducing propofol anaesthetic requirements during total i.v. anaesthesia (TIVA) maintenance and to evaluate its effect on early recovery from anaesthesia. METHODS: Forty adult patients undergoing elective laparoscopic cholecystectomy under TIVA were randomly allocated into the lidocaine group (administered 1.5 mg kg(-1) i.v. lidocaine over 5 min followed by 2 mg kg(-1) h(-1)) and the control group (administered an equal volume of saline). Propofol was administered using a target-controlled infusion to maintain the bispectral index values between 40 and 60. After surgery, all infusions were discontinued and the time to extubation was recorded. Serial arterial blood samples were drawn to assess drug plasma levels. RESULTS: The maintenance dose of propofol was significantly lower in the lidocaine group [6.00 (0.97) mg kg(-1) h(-1)] vs the control group [7.25 (1.13) mg kg(-1) h(-1); P=0.01]. Propofol plasma levels measured at the end of the infusion were 3.71 (0.89) µg ml(-1) in the lidocaine group and 3.67 (1.28) µg ml(-1) in the control group (P=0.91). The median time to extubation was longer (11.0 min; range: 10.0-21.0) in the lidocaine group vs the control group (8.3 min; range: 5.5-12.5; P=0.02). CONCLUSIONS: I.V. lidocaine reduces propofol requirements during the maintenance phase of TIVA, particularly during surgical stimulation. This sparing effect is associated with an increased time to extubation. Owing to its effect on early recovery from anaesthesia, i.v. lidocaine should be taken into account when used as a component of i.v. anaesthesia.

Pre-oxygenation in the obese patient: effects of position on tolerance to apnoea.

BACKGROUND: In obese patients, reduced functional residual capacity exacerbated by supine position might decrease the effectiveness of pre-oxygenation and the tolerance to apnoea. The aim of this study was to compare the effect of body posture during pre-oxygenation, sitting or supine, on its effectiveness in obese patients. METHODS: Forty obese patients (BMI > or =35 kg m(-2)) undergoing surgery with general anaesthesia were randomly assigned to one of two groups: Group 1 (sitting, n=20) or Group 2 (supine, n=20). In the predetermined body position, pre-oxygenation was achieved with eight deep breaths within 60 s and an oxygen flow of 10 litre min(-1). After rapid sequence induction of anaesthesia in decubitus position, the trachea was intubated and the patient was left apneic and disconnected from the anaesthesia circuit until Sp(o2) decreased to 90%. The time taken for desaturation to 90% from the end of induction of anaesthesia was recorded. Arterial blood oxygen tension was measured before (baseline) and after pre-oxygenation. Values were compared with two-way anova and unpaired Student's t-test. RESULTS: Oxygen and carbon dioxide tensions were similar between groups, both at baseline and after pre-oxygenation. However, the mean time to desaturation to 90% was significantly longer in the sitting group compared with the supine group [mean (SD): 214 (28) vs 162 (38) s, P<0.05]. CONCLUSIONS: Pre-oxygenation in sitting position significantly extends the tolerance to apnoea in obese patients when compared with the supine position.