A comparative randomized study of awareness during two anesthetic induction techniques in old aged patients using isolated forearm technique

Abstract

Background & Objective: Awareness under anesthesia is defined as intraoperative consciousness and/or postoperative recall of surgical events. The isolated forearm technique (IFT) is a technique that has the ability to assess consciousness of the external world through a verbal command during general anesthesia. It provides live information about the presence of consciousness. We compared inhalational induction technique versus intravenous induction technique regarding awareness during laryngoscopy and intubation in elderly patients. Design: A prospective, randomized trial Methodology: A total of 50 patients scheduled for elective surgery under general anesthesia; aged 60 to 80 years were recruited. Patients were randomized into either Group A (inhalational induction group) or Group B (total intravenous induction group). Awareness reaction using IFT technique was observed during laryngoscopy and intubation phase to identify awareness incidence. A patient was considered a responder if IFT score > 2. Results: At laryngoscopy and intubation phase, 32% of cases had an awareness reaction in intravenous induction group (Group B): While in the inhalational induction group (Group A), only 8% of cases had an awareness reaction. Additionally, none of the patients, suffered from postoperative explicit recall as detected by modified Brice questionnaire (MBQ). Conclusions: On the basis of the results of our study, we conclude that intravenous induction of general anesthesia may subject old aged patients to a higher incidence of awareness when compared to inhalational induction technique. Trial Registration: NCT05019560 Abbreviations: TIVA - Total intravenous anesthesia; IFT - Isolated forearm technique; MBQ - Modified Brice questionnaire; BISTM -Bispectral Index™; ETAC - End-tidal anesthetic concentration; MAC – Minimum alveolar concentration Key words: Awareness; The modified Brice questionnaire; Elderly patients; Isolated forearm technique; Sevoflurane; TIVA Citation: Ibrahim TH, Ayoub AH, Ibrahim IM, Ismaiel MAA, Mostafa RH. A comparative randomized study of awareness during two anesthetic induction techniques in old aged patients using isolated forearm technique. Anaesth. pain intensive care 2022;26(1):81-88. DOI: 10.35975/apic.v26i1.1772 Received: November 14, 2021, Reviewed: December 18, 2021, Accepted: December 22, 2021