Journal of Anaesthesiology, Clinical Pharmacology最新文献

Background and aims: Although thoracic paravertebral blockade (TPVB) is employed in thoracic surgery to ensure satisfactory postoperative analgesia, large doses of anesthetics are required and manifestations of local anesthetic systemic toxicity (LAST) may appear. Currently, there are limited data on the pharmacokinetics of ropivacaine after continuous TPVB. The aim of this prospective study was to investigate ropivacaine kinetics, in the arterial and venous pools, after continuous TPVB and assess the risk of LAST.

Material and methods: Immediately after induction of general anesthesia, an ultrasound-guided continuous TPVB at T5 or T6 or T7 thoracic level was performed in 18 adult patients subjected to open thoracotomy. A 25-ml single bolus injection of ropivacaine 0.5% was administered through thoracic paravertebral catheter, followed by a 14 ml/h continuous infusion of ropivacaine 0.2% starting at the end of surgery. Quantification of total ropivacaine concentrations was performed using a validated high-performance liquid chromatography method. Population pharmacokinetic models were developed separately for arterial and venous ropivacaine data.

Results: The best model was one-compartment disposition with an additional pre-absorption compartment corresponding to thoracic paravertebral space. Gender had a significant effect on clearance, with females displaying lower elimination than males. Some patients had ropivacaine concentrations above the toxic threshold, but none displayed evidence of LAST. Continuous thoracic paravertebral nerve blocks provided adequate postoperative analgesia.

Conclusion: Ropivacaine doses at the upper end of clinical use (800 mg/d) did not inflict the manifestations of LAST and provided adequate postoperative pain control. Pharmacokinetic models were developed, and the effect of gender was identified.

Background and aims: Simulation is increasingly used in medical teaching. Various studies have evaluated different simulation models for training of regional anesthesia (RA). We compared the use of human cadaver and blue phantom models for training of regional anesthesia to novice postgraduate students of anesthesiology.

Material and methods: Fifty students were taught knobology of the ultrasonography (USG) machine. They were divided into two equal groups by computer-generated random number table, and the groups assigned were kept in sealed envelopes. In group BP, students were trained on a blue phantom model, and in group HC, students were trained on human cadaver. After training, a didactic video of sonoanatomy of the supraclavicular block was shown to all participants. The block performance was then judged on patients requiring supraclavicular block. The primary objective of the study was to compare the block performance time, and secondary objectives were the quality of image acquired, orientation of transducer to the target, identification of ultrasound artifacts, errors committed, complications, and success rate.

Results: The mean block performance time was shorter in group HC compared to group BP (451.96 ± 50.25 and 526.48 ± 43.486 s, respectively; P < 0.001). The image quality score, transducer orientation to the target, and identification of USG artifacts were better in group HC compared to group BP, with lesser number of needle passes.

Conclusion: Cadaver-based training produced better results compared to blue phantom simulator model for teaching of ultrasound-guided RA to novice postgraduate trainees of anesthesiology.

Background and aims: The objective of the study was to evaluate the performances of qCON and qNOX indices in pediatric populations undergoing surgery under general anesthesia (GA), focusing on the induction and recovery periods. Both the indices are derived from electroencephalogram (EEG) and implemented in the CONOX monitor (Fresenius Kabi, Germany).

Material and methods: After approval of the institutional ethics committee, this prospective observational study was conducted in pediatric patients of either sex in the age group of 1-12 years belonging to the American Society of Anesthesiology (ASA) grade I and II undergoing elective surgery under GA. Anesthetic technique was GA with or without regional analgesia (RA). All patients underwent inhalation induction and maintenance using sevoflurane. Patients were monitored with the use of a CONOX monitoring system (Fresenius Kabi, Germany), connected via a set of electrodes placed over the forehead. qCON and qNOX scores were recorded during awake (on operating table premedicated with oral midazolam 0.5 mg/kg), at induction, at loss of eyelash reflex, intubation/laryngeal mask airway (LMA) insertion, before and after regional anesthesia, surgical incision, at cessation of anesthesia, emergence, extubation, and eye-opening. Registered results were also analyzed compared with the minimum alveolar concentration of sevoflurane (MAC).

Results: A total of 46 pediatric patients were enrolled in the study with a mean age of 5.6 years. All the patients were either ASA I or II. There was a simultaneous fall and rise of qCON and qNOX upon induction and recovery, respectively. There was a rise in qNOX with surgical incision irrespective of RA. However, there was a greater rise in qNOX following surgical incision in those who did not receive RA (P = 0.33) Also both qCON (P = 0.06) and qNOX (P = 0.41) were poorly correlated with MAC values of sevoflurane during GA in the pediatric population.

Conclusions: Both qCON and qNOX values change predictably with changes in the conscious level and with different noxious stimuli. Further studies are required to confirm the findings taking into account the postoperative assessment of delirium and recall of intraoperative events.

Background and aims: Erector spinae plane block (ESPB) has been found to be simple, safe, and effective at thoracic and lumbar levels. There is no randomized controlled trial evaluating its effectiveness at sacral level. The present study was conducted to evaluate its effectiveness at sacral level for postoperative analgesia in pediatric patients undergoing hypospadias repair.

Material and methods: Forty children of 2-7 years with ASA grade I or II were included. They were randomly allocated to one of the two groups of 20 patients each. After induction of general anesthesia, patients of group I were given ultrasound-guided sacral ESPB with 1 ml/kg of 0.25% bupivacaine, and patients of group II were not given block. Postoperatively, pain was assessed using face, legs, activity, cry, consolability (FLACC) scale at 0 hour, every 15 min up to 1 hour, every half an hour up to 2 hours, 2 hourly up to 12 hours, and at 18^th hour and 24^th hour postoperatively. At FLACC score ≥4, rescue analgesia was given using 15 mg/kg paracetamol infusion. Primary objective was to compare postoperative analgesic (paracetamol) consumption, and secondary objective was time to first rescue analgesia.

Results: Mean postoperative paracetamol consumption was 360 ± 156.60 mg in group I and 997.50 ± 310.87 mg in group II (P = 0.001). Time to first rescue analgesia was 906 ± 224.51 min in group I and 205.00 ± 254.92 min in group II (P = 0.001).

Conclusion: Sacral ESPB has been found to be effective in reducing postoperative analgesic consumption in pediatric patients undergoing hypospadias repair.

Dexamethasone is routinely used in anesthesia practice and has been regarded as one of the ideal perioperative agents. It is a synthetic glucocorticoid with potent antiinflammatory action. It reduces postoperative nausea and vomiting, pain, postoperative opioid requirements after general anaesthesia as well as spinal anaesthesia. It has been used via intravenous, epidural and perineural routes. It has been used successfully in fascial blocks. It significantly decreases fatigue, shivering and postoperative sore throat and improves quality of recovery.