Ma. Warner et al., ULNAR NEUROPATHY - INCIDENCE, OUTCOME, AND RISK-FACTORS IN SEDATED ORANESTHETIZED PATIENTS, Anesthesiology, 81(6), 1994, pp. 1332-1340
Background: Ulnar neuropathy is well-recognized as a potential complic
ation of procedures performed on anesthetized patients. However, repor
ted outcomes and risk factors for this problem are based on small seri
es and anecdotes. Methods: We retrospectively reviewed the perioperati
ve courses of 1,129,692 consecutive patients who underwent diagnostic
and noncardiac surgical procedures with concurrent anesthetic manageme
nt at the Mayo Clinic from 1957 through 1991 (inclusive). The medical
diagnoses of patients who had these procedures were scanned for 26 dia
gnoses associated with neuropathy. Persistent neuropathy of an ulnar n
erve was defined as a sensory or motor deficit of greater than 3 month
s' duration. Risk factors anecdotally associated with persistent neuro
pathy were analyzed by comparing patients with an ulnar neuropathy wit
h control subjects in a 1:3 case-control study. Results:Persistent uln
ar neuropathies were identified in 414 patients, a rate of 1 per 2,729
patients. Of these, 38 (9%) patients had bilateral neuropathies. Appr
oximately equal numbers of the neuropathies included sensory loss only
or mixed sensory and motor loss. Initial symptoms for most neuropathi
es were noted more than 24 h after the procedure. Factors associated w
ith persistent ulnar neuropathy included male gender and a duration of
hospitalization of more than 14 days (P < 0.01). Neuropathy was more
likely to develop in very thin and obese patients than in patients wit
h average body habitus. Neither the type of anesthetic technique nor t
he patient position was found to be associated with this neuropathy. O
f the 382 patients who survived the Ist postoperative yr, 53% regained
complete motor function and sensation and were asymptomatic. Of those
with neuropathies persisting for more than 1 yr, most had moderate or
greater disability from pain or weakness. Conclusions: These data sug
gest that perioperative ulnar neuropathies are associated with factors
other than general anesthesia and intraoperative positioning. Men at
the extremes of body habitus who have prolonged hospitalizations are p
articularly susceptible to development of ulnar neuropathies.