Interval Neurophysiological Changes in Non Septic Critically Ill Mechanically Ventilated Patients

Abstract

Peripheral nerve changes in critically ill patients are common, sepsis being the most important risk factor. The aim of our study is to investigate interval neurophysiological changes in non septic mechanically ventilated critically ill patients, a group who has not been the focus of previous studies. Consecutive non septic mechanically ventilated critically ill patients were included. Baseline nerve conduction studies (NCS) were done within 3 days of intensive care unit admission, and 48 hours after the initiation of mechanical ventilation, and were followed up 7-8 days later. Sural and ulnar sensory, and median and peroneal motor nerves were tested. Nine patients were studied, five (56%) showed significant changes in their NCS compared to baseline. The peroneal and sural nerve amplitudes significantly dropped in all of the five affected patients, with drop of those of the median motor nerves in two, and ulnar sensory nerves in three patients. In conclusion, interval changes in peripheral nerves can exist in critically ill mechanically ventilated non septic patients. The pattern is similar to critically ill patients with sepsis. Theories of possible pathophysiology of critical illness neuropathy should not merely depend on the presence of sepsis as a trigger and other mechanisms should be investigated.