title: Brachial plexus nerve block exhibits prolonged duration in the elderly.
abstract: BACKGROUND
  Upper limb trauma occurs frequently in elderly patients for whom peripheral nerve blocks are often preferred for anesthesia. The characteristics of such regional blocks have, however, never been described in an elderly population. Therefore, the authors assessed prospectively the onset and duration of upper extremity peripheral nerve block (the mid-humeral block) in elderly and young patients undergoing emergency upper extremity surgery.
  
  
  METHODS
  Consecutive patients aged > 70 yr or < 70 yr received a mid-humeral block with a small volume of ropivacaine, 0.75%. Five milliliters was injected onto each of the musculocutaneous, radial, ulnar, and median nerves. Time to complete sensory and motor block and durations of complete sensory and motor block were assessed. Results are shown as median and its 95% confidence interval.
  
  
  RESULTS
  Median ages were 77 yr (95% CI, 72-81 yr) and 39 yr (95% CI, 27-46 yr) in the two groups. Both groups had similar times to complete sensory blockade. The elderly group had longer durations of complete sensory (390 min [range, 280-435 min] vs.150 min [range, 105-160 min]; P< 0.05) and motor (357 min [range, 270-475 min] vs. 150 min [range, 90-210 min]; P< 0.05) blockade. Duration of complete sensory block was significantly correlated with age (rho = 0.56; P< 0.05).
  
  
  CONCLUSIONS
  Age is a major determinant of duration of complete motor and sensory blockade with peripheral nerve block, perhaps reflecting increased sensitivity to conduction failure from local anesthetic agents in peripheral nerves in the elderly population.
authors.affiliation: Department of Anesthesiology, Emergency Medicine and Surgery, Centre Hospitalier Universitaire (CHU) Pitié-Salpêtrière, Paris, France. xavier.paqueron@psl.ap-hop-paris.fr
authors.forename: Xavier
authors.initials: X
authors.lastname: Paqueron
authors.forename: Gilles
authors.initials: G
authors.lastname: Boccara
authors.forename: Mouhssine
authors.initials: M
authors.lastname: Bendahou
authors.forename: Pierre
authors.initials: P
authors.lastname: Coriat
authors.forename: Bruno
authors.initials: B
authors.lastname: Riou
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001917:Brachial Plexus / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009407:Nerve Block; D013997:Time Factors