A retrospective observational study of neuromuscular monitoring practice in 30,430 cases from six Danish hospitals.

Timely application of objective neuromuscular monitoring can avoid residual neuromuscular blockade. We assessed the frequency of objective neuromuscular monitoring with acceleromyography and the last recorded train-of-four ratio in a cohort of Danish patients. We extracted data from all patients receiving general anaesthesia from November 2014 to November 2016 at six hospitals in the Zealand Region of Denmark. Acceleromyography was available in all operating rooms and data were recorded automatically. The primary outcome measure was acceleromyography use in patients receiving neuromuscular blocking agents, divided into non-depolarising agents and succinylcholine only. The dataset included 76,743 cases, of which 30,430 received a neuromuscular blocking drug. Non-depolarising drugs were used in 16,525 (54%) and succinylcholine as the sole drug in 13,905 (46%) cases. Acceleromyography was used in 14,463 (88%) patients who received a non-depolarising neuromuscular blocking drug and in 4224 (30%) receiving succinylcholine alone. Acceleromyography use varied between the departments from 58% to 99% for non-depolarising drugs and from 3% to 79% for succinylcholine alone. The median (IQR [range]) of the last recorded train-of-four ratio before tracheal extubation was 0.97 (0.90-1.06 [0.01-2.20]) when non-depolarising drugs were used, and was less than 0.9 in 22% of cases. The OR for oxygen desaturation was higher with the use of succinylcholine [2.51 (95%CI 2.33-2.70) p < 0.001] and non-depolarising drugs [2.57 (95%CI 2.32-2.84) p < 0.001] as compared with cases where no neuromuscular blockade drug was used. In conclusion, acceleromyography was almost always used in cases where non-depolarising neuromuscular blocking drugs were used, but a train-of-four ratio of 0.9 was not always achieved. Monitoring was used in less than 30% of cases where succinylcholine was the sole drug used.

Sensory distribution of the lateral femoral cutaneous nerve block - a randomised, blinded trial.

BACKGROUND: The lateral femoral cutaneous nerve (LFCN) block may be used for post-operative pain management in patients undergoing total hip arthroplasty. The aim of this trial was to investigate the sensory coverage of the posterior and the lateral incision lines and the involvement of the femoral nerve after an LFCN block. METHODS: The study was a randomised, blinded trial in 20 healthy volunteers. All subjects received a bilateral LFCN block randomised to 8 ml ropivacaine on the right side and 8 ml isotonic saline on the left side, or vice versa. An orthopaedic surgeon depicted the incision lines (invisible to the investigators) prior to block performance. The distribution of the blocked area and the coverage of the incision lines were assessed with temperature discrimination and pinprick test before unblinding the incision lines. Pain during tonic heat stimulation and involvement of the femoral nerve by measuring quadriceps strength were assessed. RESULTS: The mean difference in block coverage of the posterior (primary outcome) and the lateral incision lines tested with temperature discrimination were 5.8% (95% CI: -2.2 to 14.0%, P = 0.146) and 18.9% (95% CI: 6.5-31.4%, P = 0.005), respectively, comparing the active with the placebo side. A varying anatomic distribution area was observed. No clinically significant differences for experimental pain and quadriceps muscle strength were found. The block failure rate was 15%. CONCLUSION: An LFCN block consisting of 8 ml 0.75% ropivacaine had limited coverage of the posterior and lateral incision lines.

Lateral femoral cutaneous nerve block after total hip arthroplasty: a randomised trial.

BACKGROUND: Peripheral regional nerve blocks are commonly used for pain management after lower extremity surgery, but motor blockade can be a significant concern. The lateral femoral cutaneous nerve (LFCN) is a purely sensory nerve from the lumbar plexus. We hypothesised that an LFCN block would reduce movement-related pain after total hip arthroplasty (THA) in patients with moderate-to-severe pain. METHODS: Sixty patients with visual analogue scale (VAS) score > 40 mm during 30-degree active flexion of the hip on either the first or second postoperative day after THA were included in this prospective, randomised, blinded, placebo-controlled trial. Group A received an LFCN block with 8 ml of 0.75% ropivacaine followed after 45 min by an additional LFCN block with 8 ml of saline. Group B received an LFCN block with 8 ml of saline followed after 45 min by an additional LFCN block with 8 ml of 0.75% ropivacaine. RESULTS: We found a difference of 17 mm (95% CI, 4-31 mm; P < 0.02) in VAS pain score during 30-degree flexion of the hip 45 min after the first block (primary outcome) in favour of group A. No other significant difference between groups regarding pain during mobilisation and at rest was found. The overall non-responder rate (< 15 mm pain reduction) was 42%. CONCLUSIONS: LFCN block reduced movement-related pain in patients with moderate-to-severe pain after THA. The substantial non-responder rate limits recommendations of this block as part of a standard analgesic treatment regimen.