Analgesic efficacy of bilateral superficial cervical plexus block for thyroid surgery: meta-analysis and systematic review.

BACKGROUND: Thyroid surgery is moderately painful, but is increasingly being considered as a day-case procedure. Bilateral superficial cervical plexus block (BSCPB) provides an adjuvant technique to facilitate this approach, but there is great evidential heterogeneity in randomised controlled trials (RCTs) about its use. METHODS: A systematic search, critical appraisal, and analysis of RCTs was performed. Trials investigating preoperative or postoperative BSCPB compared with control in patients undergoing thyroid surgery via neck incision were included. Odds ratio (OR) and 95% confidence interval (95% CI) were calculated for dichotomous data, whilst continuous data were analysed using standard mean difference. Primary outcome was rescue analgesic requirement in the first 24 postoperative hours. Secondary outcomes were visual analogue scale (VAS) scores at 0, 4, and 24 h, time until first analgesic request, intraoperative analgesic requirements, length of hospital stay, and incidence of postoperative nausea and vomiting (PONV). RESULTS: Fourteen RCTs published between 2001 and 2016 including 1154 patients were included. The overall effect of BSCPB compared with control showed a reduction in analgesic requirement (OR 0.30; 95% CI 0.18, 0.51; P<0.00001). There was improvement in VAS scores (P<0.002) and time to first analgesic requirement in the BSCPB group (P<0.00001). Length of hospital stay was reduced by 6 h by use of BSCPB. There was no significant change in the incidence of PONV with its use (OR 0.82; 95% CI 0.49-1.37; P=0.44). CONCLUSIONS: BSCPB offers analgesic efficacy in the early postoperative period for up to 24 h after thyroid surgery, with reduced length of hospital stay, but without any beneficial effect on PONV.

Reversal of residual neuromuscular block: complications associated with perioperative management of muscle relaxation.

The use of anticholinesterases to reverse residual neuromuscular block at the end of surgery became routine practice in the 1950s. These drugs could only be used when recovery from block was established [two twitches of the train-of-four (TOF) count detectable] and concern was expressed about their cholinergic side-effects. By the 1990s, it was recognized that failure to reverse residual block adequately to a TOF ratio (TOFR) >0.7 was associated with increased risk of postoperative pulmonary complications (POPCs) following the long-acting non-depolarizing neuromuscular blocking drug (NDNMBD) pancuronium. By 2003, and the introduction of acceleromyography, a TOFR ≥0.9 was considered necessary to protect the airway from aspiration before tracheal extubation. It was also considered that four, not two, twitches of the TOF should be detectable before neostigmine was given. Use of any NDNMBD was subsequently shown to be associated with increased risk of POPCs, but it was thought that neostigmine reduced that risk. Recently, there has been conflicting evidence that use of neostigmine might increase the incidence of POPCs. Although sugammadex has been shown to rapidly reverse profound neuromuscular block from aminosteroidal agents, there is currently no evidence that sugammadex is superior to neostigmine in its effect on POPCs. Other new antagonists, including cysteine to degrade CW002 and calabadion 1 and 2 to antagonize aminosteroidal and benzylisoquinolium NDNMBDs, are being studied in preclinical and clinical trials. Quantitative neuromuscular monitoring is essential whenever a NDNMBD is used to ensure full recovery from neuromuscular block.

Effect of intrathecal magnesium in the presence or absence of local anaesthetic with and without lipophilic opioids: a systematic review and meta-analysis.

Spinal anaesthesia is the primary anaesthetic technique for many types of surgery. Adjuncts to the local anaesthetics (LA) used in spinal anaesthesia can exhibit undesirable side-effects, limiting their use, but magnesium may have advantages in this respect. We sought randomized control trials (RCTs) in patients undergoing all types of surgery and in women in labour to compare the effect of intrathecal magnesium sulphate ± LA ± lipophilic opioid (experimental group) with the use of either intrathecal lipophilic opioids ± LA or LA only (control group). The primary outcome was the duration of spinal anaesthesia. Secondary outcomes were: onset and time to maximal sensory blockade, onset of motor block, and duration of sensory and motor blockade. We found 15 RCTs comprising 980 patients. The duration of spinal anaesthesia was significantly increased in the experimental group [standardized mean difference (SMD) -1.05 (-1.70, -0.41) (P = 0.001)], compared with the control group. This increased duration of spinal anaesthesia was seen in non-obstetric studies, SMD -1.38 (-2.11, -0.66) (P = 0.0002), but not in obstetric studies, SMD -0.55 (-1.87, 0.77) (P = 0.41). There was no delay in the onset of sensory or motor blockade. The incidence of hypotension and pruritus was similar in both groups. Heterogeneity was high in all outcome measures. The duration of spinal anaesthesia may be increased by the addition of magnesium to lipophilic opioids ± LA.

Reversal of profound rocuronium or vecuronium-induced neuromuscular block with sugammadex in isoflurane-anaesthetised dogs.

This study evaluated the use of sugammadex for reversal of profound neuromuscular blockade induced with rocuronium or vecuronium in dogs. Anaesthesia was induced and maintained with isoflurane in oxygen in eight dogs on two occasions. Neuromuscular blockade was monitored using peroneal nerve stimulation and acceleromyography. Rocuronium 0.6 mg/kg or vecuronium 0.1mg/kg was administered intravenously (IV), followed 5 min later by sugammadex 8 mg/kg IV. Lag and onset time of rocuronium and vecuronium, lag time from sugammadex injection to recovery of first twitch response, recovery of T1/T0 to 25% and 75%, recovery index, and time to recovery of the train-of-four ratio (T4/T1) to 0.9 were recorded. Cardiovascular and respiratory parameters were also noted. Statistical analysis was performed using one-way ANOVA. Onset time for rocuronium (37 ± 18s; [mean ± SD]) was significantly shorter than for vecuronium (62 ± 15s) (P<0.04). No other significant differences were found between the two groups. After both rocuronium and vecuronium blockade, T4/T1 recovered to 0.9 in under 2 min after sugammadex (58.1 ± 67.8s and 98.1 ± 70.3s, respectively; P<0.32). Sugammadex can reverse profound neuromuscular blockade induced by vecuronium or rocuronium safely and rapidly in isoflurane-anaesthetised dogs.