The role of polyneuropathy in motor convalescence after prolonged mechanical ventilation.

OBJECTIVE

To test the hypothesis that prolonged motor recovery after long-term 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 studies in the intensive care unit (ICU). During a 1-year follow-up, amount of time was recorded to reach a rehabilitation end point.

SETTING

The general ICU of a community hospital.

PATIENTS

Fifty patients younger than 75 years who were receiving mechanical ventilation for more than 7 days.

MAIN OUTCOME MEASURES

A rehabilitation end point was defined as return of normal muscle strength and ability to walk 50 m independently.

RESULTS

In 29 of 50 patients, an EMG diagnosis of polyneuropathy was made in the ICU. Patients with polyneuropathy had a higher mortality in the ICU (14 vs 4; P = .03), probably related to multiple organ failure (22 vs 11; P = .08) or aminoglycoside treatment of suspected gram-negative sepsis (17 vs 4; P = .05). Rehabilitation was more prolonged in 12 patients with polyneuropathy than in 12 without polyneuropathy (P = .001). Of nine patients with delays beyond 4 weeks, eight had polyneuropathy, five of whom had persistent motor handicap after 1 year. In particular, axonal polyneuropathy with conduction slowing on EMG indicated 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.