Local anaesthetic delivery regimens for peripheral nerve catheters: a systematic review and network meta-analysis.

There are numerous possible techniques for delivering local anaesthetic through peripheral nerve catheters. These include continuous infusions, patient-controlled boluses and programmed intermittent boluses. The optimal delivery regimen of local anaesthetic is yet to be conclusively established. In this review, we identified prospective trials of delivery regimens through peripheral nerve catheters. Our primary outcome was visual analogue scale scores for pain at 48 h. Secondary outcomes were: visual analogue scores at 24 h; patient satisfaction scores; rescue opioid use; local anaesthetic consumption; and nausea and vomiting. Network meta-analysis was used to compare these outcomes. Predefined sub-group analyses were performed. Thirty-three studies enrolling 1934 participants were included. In comparison with continuous infusion, programmed intermittent boluses improved visual analogue pain scores at both 48 and 24 h, the weighted mean difference (95%CI) being -0.63 (-1.12 to -0.14), p = 0.012 and -0.48 (-0.92 to -0.03), p = 0.034, respectively. Programmed intermittent boluses also improved satisfaction scores, the weighted mean difference (95%CI) being 0.70 (0.10-1.31), p = 0.023, and reduced rescue opioid use, the weighted mean difference (95%CI) in oral morphine equivalent at 24 h being -23.84 mg (-43.90 mg to -3.77 mg), p = 0.020. Sub-group analysis revealed that these findings were mostly confined to lower limb and truncal catheter studies; there were few studies of programmed intermittent boluses for upper limb catheters. Programmed intermittent boluses may provide optimal delivery of a local anaesthetic through peripheral nerve catheters. Further research is warranted, particularly to delineate the differences between upper and lower limb catheter locations, which will help clarify the clinical relevance of these findings.

Design and validation of the Regional Anaesthesia Procedural Skills Assessment Tool.

The aim of this study was to create and evaluate the validity, reliability and feasibility of the Regional Anaesthesia Procedural Skills tool, designed for the assessment of all peripheral and neuraxial blocks using all nerve localisation techniques. The first phase was construction of a 25-item checklist by five regional anaesthesia experts using a Delphi process. This checklist was combined with a global rating scale to create the tool. In the second phase, initial validation by 10 independent anaesthetists using a test-retest methodology was successful (Cohen kappa ≥ 0.70 for inter-rater agreement, scores between test to retest, paired t-test, p > 0.12). In the third phase, 70 clinical videos of trainees were scored by three blinded international assessors. The RAPS tool exhibited face validity (p < 0.026), construct validity (p < 0.001), feasibility (mean time to score < 3.9 min), and overall reliability (intraclass correlation coefficient 0.80 (95% CI 0.67-0.88)). The Regional Anaesthesia Procedural Skills tool used in this study is a valid and reliable assessment tool to score the performance of trainees for regional anaesthesia.

Incidence of residual neuromuscular blockade in a post-anaesthetic care unit.

We conducted a prospective observational study to assess the incidence of residual neuromuscular blockade (RNMB) in a post-anaesthetic care unit (PACU) of a tertiary hospital. The subjects were 102 patients undergoing general anaesthesia with neuromuscular blockade (NMB). The procedural anaesthetists were unaware of their patients' inclusion in the study, and the choice of muscle relaxant and use of reversal agents were at the anaesthetists' discretion. On arrival to the PACU, the train-of-four ratio was assessed using electromyography, repeated every five minutes until the train-of-four ratio exceeded 0.9. RNMB was defined as a train-of-four ratio < 0.9. The requirement for airway support, incidence of desaturation while in the PACU and time to eligibility for PACU discharge were recorded. The mean interval between the last dose of relaxant and arrival in the PACU for patients with RNMB was 81 minutes. An intermediate-acting muscle relaxant had been used for most patients. Despite this, RNMB was observed in 31% (95% confidence interval 25 to 47%) of patients. Our findings suggest that RNMB in the PACU is common. As RNMB may predispose to postoperative complications, anaesthetists should utilise quantitative monitoring to assess neuromuscular blockade and optimise reversal use. Anaesthetists should be aware that intervals between the last dose of relaxant of well over one hour do not exclude the possibility of RNMB, even when using intermediate-acting neuromuscular blockade agents.

Management of a parturient with respiratory failure secondary to cystic fibrosis.

A 21-year-old with end-stage respiratory failure and cor pulmonale due to cystic fibrosis became pregnant. Her forced expiratory volume in 1 s (FEV1) was 17% of that predicted antenatally, and termination was strongly advised on the grounds that continuing pregnancy was likely to be fatal. She elected to continue with the pregnancy and gave birth by lower segment caesarean section at 29 weeks and 5 days' gestation. Despite a problematic postnatal course, she was successfully discharged home and, 7 months postnatally, continues to live at home with her partner and their baby. There are no previous reports of cystic fibrosis patients with this level of respiratory impairment surviving pregnancy.