Early detection of ICU-acquired weakness in septic shock patients ventilated longer than 72 hours

Abstract

Purpose: ICU acquired weakness, comprising Critical Illness Polyneuropathy (CIP) and Myopathy (CIM) is associated with immobilization and prolonged mechanical ventilation. This study aims to assess feasibility of early detection of CIP and CIM by peroneal nerve test (PENT) and sensory sural nerve action potential (SNAP) screening in patients with septic shock invasively ventilated for more than 72 hours and to investigate risk factors associated with CIP and CIM. Methods: We performed repetitive PENT screening from 72 hours after intubation until detecting a pathological response. We tested SNAPs in pathological PENT to differentiate CIP from CIM. Muscle strength examination was performed in awake patients and time from intubation to first in-bed and out-of-bed mobilization were recorded.Results: Eighteen patients were screened with PENT and 88.9% had abnormal responses. Mean time between intubation and first screening was 94.38 (+ 22.41) hours. Seven patients (38.9%) had CIP, 2 (11.1%) had CIM, 1 (5.6%) had CIP and CIM, 6 (33.3%) had a pathological response at PENT associated with ICU acquired weakness but no SNAP could be performed to differentiate between CIP and CIM and 2 patients had (11.1%) had no peripheral deficit. In the patients where it could be performed, muscle strength testing concorded with electrophysiological findings. Twelve patients (66.7%) had out-of-bed mobilization 10.8 (+ 7.4) days after admission. Conclusion: CIP and CIM are frequent in septic patients and can be detected before becoming symptomatic with simple bedside tools. Early detection of CIP and CIM opens new possibilities for timely management of CIP and CIM through preventive measures such as passive and active mobilization.