Which muscle relaxants should be used in day surgery and when.

PURPOSE OF REVIEW: After myorelaxants, myalgia and residual curarization may complicate recovery. Local anaesthesia and minimally invasive airway management make myorelaxants disputable in many outpatient procedures; nevertheless, neuromuscular blockade may be necessary to facilitate intubation or maintain muscle relaxation. Agent selection criteria are discussed.

RECENT FINDINGS: Reduced hospital time is not associated with central neuraxial or peripheral nerve block. To reduce the risk for residual block, neuromuscular monitoring is mandatory. Use of reversal agents should not be restricted, although studies have shown higher incidence of postoperative nausea and vomiting following their use. Higher succinylcholine dosage is followed by lower incidence of myalgia. The relationship between fasciculation and myalgia is unclear. Sodium channel blockers or nonsteroidal antiinflammatory drugs may prevent myalgia. Sugammadex functions as a chelating agent.

SUMMARY: Ear-nose-throat, open eye surgery and laparoscopy may demand myoresolution. Regional and minimally invasive anaesthesia are alternative solutions. Central and peripheral nerve blocks are associated with increased induction time, reduced pain scores, and decreased need for analgesics. Central neuraxial block, however, is associated with prolonged outpatient unit stay. Bad intubating conditions may cause pharyngo-laryngeal complications: the decision to avoid myorelaxants for tracheal intubation appears illogical. Incidence of postoperative residual curarization remains very high. Sugammadex offers new perspectives.