Critical illness polyneuropathy in multiple organ dysfunction syndrome and weaning from the ventilator

Abstract

Background: Acute axonal polyneuropathy has been found in patients with multiple organ dysfunction syndrome. This 'critical illness polyneuropathy' (CIP) has been associated with difficult weaning from the ventilator in retrospective studies.

Objective: To test the hypothesis that CIP is related to the degree and number of organ dysfunctions, and to weaning problems.

Design: Prospective study of 18 months.

Setting: A multidisciplinary intensive care unit in a general hospital

Subjects: Thirty-eight patients under 75 years of age who had been mechanically ventilated for more than 7 days, without previous signs of or risk factors for polyneuropathy.

Measures: Organ dysfunctions were quantified using a dynamic scoring system (0-12 points). Electromyography studies were performed during mechanical ventilation to identify patients with and without CIP.

Results: CIP was present in 18 out of 38 patients and associated with an increased organ dysfunction score (5.3 +/- 1.8 vs. 3.6 +/- 1.5; p = 0.003) and number of organs involved [median (range): 4 (3-5) vs. 2 (1-4); p = 0.009], in particular cardiovascular (p = 0.003), renal (p = 0.04), and hematopoietic failure (p = 0.04). Patients with polyneuropathy were ventilated longer, but this was not clearly due to more difficult weaning [median: 16.5 (1-48) vs. 9.5 (1-38) days; p = 0.26]. Polyneuropathy was present in 2 of 4 patients with normal weaning.

Conclusions: Axonal polyneuropathy is related to the severity of multiple-organ-dysfunction syndrome. Its presence does not necessarily implicate difficult weaning from artificial ventilation.