Intraoperative Anaesthesia Awareness Following Induction of Anaesthesia (ConsCIOUS)

An International Multi-Centre Cohort Study of the Incidence of Anaesthesia Awareness Following Laryngoscopy and Intubation: The CONSciousness, Connectedness and IntraOperative Unresponsiveness Study (ConsCIOUS)

A primary aim of anaesthesia is to prevent awareness of surgery; ablation of the experience of surgery is the most secure way to prevent awareness with recall. Fortunately the incidence of awareness with recall (the patient can spontaneously remember the intraoperative event) is very rare (0.1-0.2%). However the investigators systematic review suggests that consciousness of intraoperative events may occur in approximately 37% of patients in experimental studies (as identified by the validated clinical procedure the isolated forearm test that does not require postoperative recall of the event). In this international cohort study, recruiting a minimum sample of 200 patients, the investigators will investigate the incidence of anaesthesia awareness (as identified by the isolated forearm test) following the induction of anaesthesia and before surgery.

Study Overview

• Status: Completed
• Conditions: Anaesthesia

• Study Type: Observational
• Enrollment (Actual): 260

Contacts and Locations

Study Locations

• New Zealand
  • Waikato
    • Hamilton, Waikato, New Zealand
      • University of Auckland
• United States
  • Michigan
    • Ann Arbor, Michigan, United States
      • University of Michigan
  • Wisconsin
    • Madison, Wisconsin, United States
      • University of Wisconsin

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Adult patients undergoing anaesthesia requiring intubation and layngoscopy

Description

Inclusion Criteria:

• Adult patients clinically requiring intubation will be included in this cohort.
• Patients must be able to follow the isolated forearm technique commands when awake and prior to their operation will be included in this cohort.

Exclusion Criteria:

• Contraindication to isolated forearm technique test such as unable to have tourniquet on arm for the isolated forearm technique (e.g. lymphedema or operative site).

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of isolated forearm test responsiveness following laryngoscopy and intubation	Following induction of anaesthesia, and securing the airway (laryngoscopy and intubation) the patient will be asked to squeeze the anaesthetist's hand as a surrogate of awareness under anaesthesia.	The test will occur within one minute of securing the airway (laryngoscopy and intubation).

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of isolated forearm test responsiveness before laryngoscopy and intubation	Following induction of anaesthesia, and prior to securing the airway (before laryngoscopy and intubation) if safe to do so, the patient will be asked to squeeze the anaesthetist's hand as a surrogate of anaesthesia awareness.	The test will occur in the minute prior to securing the airway (laryngoscopy and intubation).
Incidence of anaesthesia awareness with recall	After the operation and emergence from anaesthesia, and within 24 hours of the operation, the patient will be asked, using the structured Modified Brice questionnaire, about recall of intraoperative events (anaesthesia awareness).	Within 24 hours of the operation
Patient satisfaction questionnaire	Within 24 hours of the operation and emergence from anaesthesia, the patient will be asked to complete a patient satisfaction questionnaire rating the anaesthetic care they received. This will cover the preoperative information they were given, their emergence from anaesthesia, their pain control, experience of nausea and vomiting and their general experience. They will be asked to rate their care from four options: very satisfied, satisfied, dissatisfied and very dissatisfied.	Within 24 hours of the operation and emergence from anaesthesia

Collaborators and Investigators

• Sponsor: University of Wisconsin, Madison
• Collaborators: University College London Hospitals; University of Michigan; RWTH Aachen University; University of Witten/Herdecke; University of Groningen; University of Auckland, New Zealand; Centre Hospitalier Régional de la Citadelle
• Investigators: Principal Investigator: Robert D Sanders, MBBS PhD FRCA, University of Wisconsin, Madison

Publications and helpful links

General Publications

• Gaskell AL, Hight DF, Winders J, Tran G, Defresne A, Bonhomme V, Raz A, Sleigh JW, Sanders RD. Frontal alpha-delta EEG does not preclude volitional response during anaesthesia: prospective cohort study of the isolated forearm technique. Br J Anaesth. 2017 Oct 1;119(4):664-673. doi: 10.1093/bja/aex170.

Study record dates

Study Major Dates

• Study Start: March 1, 2015
• Primary Completion (Actual): September 1, 2015
• Study Completion (Actual): October 1, 2015

Study Registration Dates

• First Submitted: September 2, 2014
• First Submitted That Met QC Criteria: September 22, 2014
• First Posted (Estimate): September 25, 2014

Study Record Updates

• Last Update Posted (Estimate): April 6, 2016
• Last Update Submitted That Met QC Criteria: April 4, 2016
• Last Verified: April 1, 2016

More Information

Terms related to this study

• Keywords: Anaesthesia; Intubation; Laryngoscopy; Responsiveness; Isolated forearm test
• Additional Relevant MeSH Terms: Pathologic Processes; Intraoperative Complications; Intraoperative Awareness
• Other Study ID Numbers: ConsCIOUS