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summary
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The incidence of systemic local anesthetic toxicity showed different risk profiles at different injection sites. In order of decreasing incidence of systemic toxicity events:
1. Paravertebral – OR 3.62 [95% CI, 1.33–7.86]
2. Upper limb — OR 1.75 [95% CI, 0.93–2.99]
3. Lower limb — OR 0.24 [95% CI, 0.05–0.71]
4. Trunk — 0.00 [95% CI, 0–0.94]
Of the 25,336 peripheral nerve blocks in the study, there were only 22 episodes of local anesthetic toxicity. 12 events occurred in the 20,401 PNBs performed with ultrasound guidance and 10 events in the 4,745 blocks performed without ultrasound.
Barrington MJ Kluger R. Ultrasound guidance reduces the risk of local anesthetic systemic toxicity following peripheral nerve blockade. Reg Anesth Pain Med. 2013 Jul 1; 38 (4): 289-99.
  Daniel Jolley
comment
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Important to note that the 9 studies included for meta-analysis (524 patients in total) were quite heterogenous: 7 performed under spinal anaesthesia and 2 under general; TAP performed using anatomical landmarks in 3 and ultrasound in 6; spinals used various doses of fentanyl and/or morphine; and the TAP blocks used ropivacaine (4), bupivacaine (4) or levobupivacaine (1). Post-operative analgesic regimes also varied.
Thus these findings should be cautiously applied to your local setting.
Mishriky BM, George RB, Habib AS. Transversus abdominis plane block for analgesia after Cesarean delivery: a systematic review and meta-analysis. Can J Anaesth. 2012 Aug 1; 59 (8): 766-78.
  Daniel Jolley
summary
1
Meta-analysis of 10 RCTs totalling 633 subjects showed that while pain at rest following laparoscopic surgery was reduced by transverse abdominis plane block, early (0-4 h) pain was only moderately reduced (-2.4 cm) and late pain (24 hours) minimally reduced (-1.3 cm). Pain with movement was not significantly different between TAP blocks and controls.
De GS, Castro-Alves LJ, Nader A et al. Transversus abdominis plane block to ameliorate postoperative pain outcomes after laparoscopic surgery: a meta-analysis of randomized controlled trials. Anesth. Analg. 2014 Feb 1;118(2):454-63.
  Daniel Jolley
summary
3
POISE showed that for every 1000 patients receiving metoprolol, 15 were prevented from suffering a myocardial infract, 3 from requiring cardiac revascularization along with 7 new cases of atrial fibrillation, but at a cost of causing an excess 8 deaths, 5 strokes, 53 hypotensive events and 42 episodes of bradycardia.
The harm associated with perioperative beta-blockade, at least in the form of non-titrated extended-release metoprolol, is greater than the demonstrated benefit. For every two cases of myocardial infract avoided there is one excess death.
POISE Study Group, Devereaux PJ, Yang H et al. Effects of extended-release metoprolol succinate in patients undergoing non-cardiac surgery (POISE trial): a randomised controlled trial. Lancet. 2008 May 31;371(9627):1839-47.
  Daniel Jolley
summary
1
Retrospective studies show that a single anesthesia exposure before age 3 may undermine language acquisition and abstract reasoning, and exposure to two or more anesthetics before age 2 almost doubles the risk of attention-deficit hyperactivity disorder, although in both cases causality has not yet been established.
Olsen EA Brambrink AM. Anesthesia for the young child undergoing ambulatory procedures: current concerns regarding harm to the developing brain. Curr Opin Anaesthesiol. 2013 Dec 1;26(6):677-84.
  Daniel Jolley
summary
0
Nerve block duration may be extended by adrenaline, clonidine, dexmedetomidine, dexamethasone, and possibly midazolam, tramadol and magnesium. Other than adrenaline there is however no longterm data demonstrating safety. Intra-articular adjuvant benefit has been shown for tramadol, magnesium, dexmedetomidine, clonidine, ketamine, ketorolac and morphine, but the evidence is not strong enough to support routine use.
Barreveld A, Witte J, Chahal H et al. Preventive analgesia by local anesthetics: the reduction of postoperative pain by peripheral nerve blocks and intravenous drugs. Anesth. Analg. 2013 May 1;116(5):1141-61.
  Daniel Jolley
summary
1
Barreveld et al. show that LA administered either IV or via block; before, during or after surgery, significantly reduces postoperative pain and opioid consumption.
Specifically in:
• Total knee arthroplasty (femoral, sciatic and lumbar plexus b., single-shot or continuous)
• Total hip arthroplasty (continuous lumbar plexus; intra-articular LA)
• Knee arthroscopy (single-shot lumbar plexus; IA LA; single-shot femoral nerve ± sciatic).
• Arthroscopic shoulder surgery - interscalene b., single-shot or continuous. IA is not beneficial.
• Hand & forearm surgery - axillary b. offers analgesic benefits only on day of surgery.
• TAP block is beneficial for laparoscopic, open appendectomy, abdominal surgery, cesarean section, and TAH.
Barreveld A, Witte J, Chahal H et al. Preventive analgesia by local anesthetics: the reduction of postoperative pain by peripheral nerve blocks and intravenous drugs. Anesth. Analg. 2013 May 1;116(5):1141-61.
  Daniel Jolley
summary
1
Monitoring neuromuscular blockade with TOF at the eye muscles (orbicularis oculi) results in a 5 times greater risk (adjusted odds ratio) of postoperative residual curarization (PORC) than monitoring at the hand (adductor pollicis) when PORC is defined by TOFR < 90% using acceleromyography.
PORC was nonetheless common in both groups, occurring in 52% and 22% respectively.
Thilen SR, Hansen BE, Ramaiah R et al. Intraoperative neuromuscular monitoring site and residual paralysis. Anesthesiology. 2012 Nov 1;117(5):964-72.
  Daniel Jolley
summary
1
Fink & Hollman describe and refute several commonly-held myths regarding neuromuscular pharmacology. Their evidence-supported arguments are:
1. Intubating patients without muscle relaxants is less safe and sub-optimal.
2. Even if you know muscle relaxant pharmacokinetics, it is sufficiently unpredictable that neuromuscular monitoring and reversal is still necessary.
3. Post-operative residual curarization (PORC) is clinically significant with real consequences.
4. Postoperative residual curarization (PORC) is common.
5. Postoperative residual curarisation (PORC) (TOFR < 0.9) can only be diagnosed with a quantitative neuromuscular monitor. Clinical tests are insufficient and poorly sensitive.
Fink H Hollmann MW. Myths and facts in neuromuscular pharmacology. New developments in reversing neuromuscular blockade. Minerva Anestesiol. 2012 Apr 1;78(4):473-82.
  Daniel Jolley
summary
1
Perioperative lidocaine (1.5 mg/kg bolus then 1.5 mg/kg/h until 1 h after skin closure) reduces the incidence of persistent post-surgical pain after breast cancer surgery at 3 months.
Grigoras A, Lee P, Sattar F et al. Perioperative intravenous lidocaine decreases the incidence of persistent pain after breast surgery. Clin J Pain. 2012 Sep 1;28(7):567-72.
  Daniel Jolley