THE ROLE OF POLYNEUROPATHY IN MOTOR CONVALESCENCE AFTER PROLONGED MECHANICAL VENTILATION

Objective.-To test the hypothesis that prolonged motor recovery after longterm ventilation may be due to polyneuropathy and can be foreseen at an early stage by electromyography (EMG). Design.-Cohort study with an entry period of 18 months. Polyneuropathy was identified by EMG st udies in the intensive care unit (ICU). During a 1-year followup, amou nt of time was recorded to reach a rehabilitation end point. Setting.- The general ICU of a community hospital. Patients.-Fifty patients youn ger than 75 years who were receiving mechanical ventilation for more t han 7 days. Main Outcome Measures.-A rehabilitation end point was defi ned as return of normal muscle strength and ability to walk 50 m indep endently. Results.-In 29 of 50 patients, an EMG diagnosis of polyneuro pathy was made in the ICU. Patients with polyneuropathy had a higher m ortality in the ICU (14 vs 4; P=.03), probably related to multiple org an failure (22 vs 11; P=.08) oraminoglycoside treatment of suspected g ram-negative sepsis (17 vs 4; P=.05). Rehabilitation was more prolonge d in 12 patients with polyneuropathy than in 12 without polyneuropathy (P=.001). Of nine patients with delays beyond 4 weeks, eight had poly neuropathy, five of whom had persistent motor handicap after 1 year. I n particular, axonal polyneuropathy with conduction slowing on EMG ind icated a poor prognosis. Conclusions.-Polyneuropathy in the critically ill is related to multiple organ failure and gram-negative sepsis, is associated with higher mortality, and causes important rehabilitation problems. EMG recordings in the ICU can identify patients at risk.