Intraoperative Cognitive Load in Anesthesia Nurses Across Anesthetic Phases (ENCOPER)

May 18, 2026 updated by: Víctor Caro, Hospital Clinic of Barcelona

Carga Cognitiva Intraoperatoria Del Enfermero/a de Anestesia Según la Fase Del Acto Anestésico: Estudio Observacional Con NASA-TLX

The goal of this observational study is to measure the cognitive load (mental effort) of anesthesia nurses during real surgical procedures at Hospital Clínic de Barcelona, Spain. The main questions it aims to answer are:

  • Does cognitive load vary across the three phases of anesthetic care (induction, maintenance, and emergence/recovery)?
  • Is cognitive load higher during general anesthesia than during spinal anesthesia with sedation?
  • How do surgical specialty and patient complexity relate to cognitive load?
  • How does monitor alarm perception relate to cognitive load during surgery?

Participants (anesthesia nurses) will complete the NASA Task Load Index (NASA-TLX) questionnaire - a validated 6-item tool measuring mental effort - three times per surgical case: after induction or spinal block, during maintenance, and after patient awakening or sedation reversal. They will also answer 4 brief questions about alarm management at the end of each case. No changes are made to clinical care. Participation adds approximately 11 minutes per surgical case.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Anesthesia nurses manage up to 72 tasks per hour during surgical procedures, including vital sign monitoring, drug administration, airway management, alarm response, and surgical team coordination. Despite this high workload, the cognitive load of anesthesia nurses has received little scientific attention. Most studies focus on simulation rather than real clinical settings.

This prospective observational study uses the Raw NASA Task Load Index (NASA-TLX) to quantify subjective cognitive load in anesthesia nurses across three phases of anesthetic care (T1: post-induction/spinal block; T2: maintenance; T3: extubation/wake up), comparing general anesthesia (endotracheal intubation or laryngeal mask) versus spinal anesthesia with sedation. Additionally, an exploratory module examines nurses' perception and management of monitor alarms and its association with cognitive load.

This is the first European study to measure cognitive load in anesthesia nurses using a validated instrument in a real surgical setting.

Study Type

Observational

Enrollment (Estimated)

50

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

  • Name: Victor Caro-Frechilla, RN, MSc
  • Phone Number: +34 633809919
  • Email: vcaro@clinic.cat

Study Locations

  • Spain
    • Catalonia
      • Barcelona, Catalonia, Spain, 08036
        • Hospital Clinic de Barcelona
        • Contact:
          • Victor Caro-Frechilla, RN, MSc
          • Phone Number: +34 633809919
          • Email: vcaro@clinic.cat
        • Principal Investigator:
          • Victor Caro-Frechilla, RN, MSc
        • Sub-Investigator:
          • Ariadna Munne Zafra, RN, MSc
        • Sub-Investigator:
          • Fernando Javier Dana Muzzio, RN, MSc, PhD(c)
        • Sub-Investigator:
          • Jessica Martinez de la Mata, RN, MSc
        • Sub-Investigator:
          • Carla Murias Verdugo, RN

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

Registered nurse anesthetists actively working at Hospital Clínic de Barcelona, a university tertiary care hospital, assigned to the following operating rooms: main surgical block, ambulatory surgery unit (CMA), interventional radiology suite (RIO), DIVAS intraoperative radiotherapy unit, and transplant operating room.

Description

Inclusion Criteria:

  • Registered nurse anesthetist actively working at Hospital Clínic de Barcelona.
  • Minimum 3 months in the current anesthesia nursing position.
  • Voluntary participation with signed informed consent.
  • Scheduled surgery (including deferred urgent surgery) or solid organ transplantation.
  • General anesthesia (endotracheal intubation or laryngeal mask airway) or spinal anesthesia with sedation.
  • Minimum duration of 30 minutes.

Exclusion Criteria:

  • Refusal to participate or withdrawal of informed consent.
  • Spinal anesthesia without sedation.
  • Exclusive regional anesthesia without sedation.
  • Sedation alone without regional technique.
  • Duration less than 30 minutes.
  • Cases involving an unexpected intraoperative emergency requiring urgent additional personnel.
  • Cases started under spinal anesthesia converted to general anesthesia for any clinical or technical reason.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
General Anesthesia (GA)
Anesthesia nurses managing surgical cases under general anesthesia (endotracheal intubation or laryngeal mask airway). Cognitive load measured at three phases: post-induction (T1), maintenance (T2), and post-extubation (T3).
Other: NASA Task Load Index (NASA-TLX)
The Raw NASA Task Load Index (NASA-TLX) is a validated self-report questionnaire measuring subjective cognitive load across six dimensions: mental demand, physical demand, temporal demand, performance, effort, and frustration (scale 0-100). Administered three times per surgical case (T1, T2, T3) by the participating anesthesia nurse. Additionally, four questions about monitor alarm perception and management are completed after T3.
Spinal Anesthesia with Sedation
Anesthesia nurses managing surgical cases under spinal anesthesia combined with intravenous sedation. Cognitive load measured at three phases: post-spinal block and sedation initiation (T1), maintenance (T2), and end of sedation (T3).
Other: NASA Task Load Index (NASA-TLX)
The Raw NASA Task Load Index (NASA-TLX) is a validated self-report questionnaire measuring subjective cognitive load across six dimensions: mental demand, physical demand, temporal demand, performance, effort, and frustration (scale 0-100). Administered three times per surgical case (T1, T2, T3) by the participating anesthesia nurse. Additionally, four questions about monitor alarm perception and management are completed after T3.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Global Raw NASA-TLX Score
Time Frame: At three time points per surgical case: T1 (5 minutes post-induction/spinal block), T2 (during maintenance, before surgical closure), and T3 (5 minutes after extubation/end of sedation ).
Subjective cognitive load measured using the Raw NASA Task Load Index (NASA-TLX), calculated as the arithmetic mean of six subscales (mental demand, physical demand, temporal demand, performance, effort, and frustration), each rated on a 0-100 scale. Administered three times per surgical case: after induction or spinal block (T1), during maintenance (T2), and after extubation or end of sedation (T3). Study duration: approximately 8 months.
At three time points per surgical case: T1 (5 minutes post-induction/spinal block), T2 (during maintenance, before surgical closure), and T3 (5 minutes after extubation/end of sedation ).

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
NASA-TLX Subscale Scores
Time Frame: Assessed at three intraoperative time points per surgical case: 5 minutes post-induction or post-spinal block, during maintenance before surgical closure, and 5 minutes post-extubation or end of sedation, over approximately 8 months of data collection.
Individual scores for each of the six NASA-TLX subscales (mental demand, physical demand, temporal demand, performance, effort, and frustration), each rated on a 0-100 scale, to identify which dimensions of cognitive load predominate at each anesthetic phase.
Assessed at three intraoperative time points per surgical case: 5 minutes post-induction or post-spinal block, during maintenance before surgical closure, and 5 minutes post-extubation or end of sedation, over approximately 8 months of data collection.
Monitor Alarm Perception Visual Analog Scale (VAS)
Time Frame: Assessed once per surgical case, immediately after patient awakening or sedation reversal, over approximately 8 months of data collection.
Exploratory measure of nurses' perceived alarm burden during each surgical case, rated on a visual analog scale from 0 (not at all) to 100 (extremely). Assessed after patient awakening or sedation reversal. Used to explore the association between alarm perception and cognitive load (NASA-TLX score).
Assessed once per surgical case, immediately after patient awakening or sedation reversal, over approximately 8 months of data collection.

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Alarm Management Behavior and Attention Interference During Intraoperative Care.
Time Frame: Perioperative - assessed once per surgical case, immediately after patient awakening or sedation reversal, over approximately 8 months of data collection.

Two exploratory Likert-scale items (1-5) completed after patient awakening or sedation reversal per surgical case:

Item 1 (Alarm Evaluation Behavior): "Non-urgent alarms have been clinically evaluated before silencing or ignoring them" (1 = Never, 5 = Always). Assesses whether nurses evaluate alarms before acting on them.

Item 2 (Alarm Interference with Attention): "Monitor alarms have interfered with my ability to pay attention to the patient during this case" (1 = Never, 5 = Always). Assesses the perceived impact of alarms on patient-focused attention.

Both items are exploratory given the absence of a validated alarm fatigue instrument in Spanish. Results will be presented with descriptive statistics and Spearman correlations with NASA-TLX scores.
Perioperative - assessed once per surgical case, immediately after patient awakening or sedation reversal, over approximately 8 months of data collection.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Hospital Clinic of Barcelona

Investigators

  • Principal Investigator: Victor Caro-Frechilla, RN, MSc, Hospital Clinic of Barcelona

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

June 1, 2026

Primary Completion (Estimated)

December 31, 2026

Study Completion (Estimated)

January 1, 2027

Study Registration Dates

First Submitted

April 28, 2026

First Submitted That Met QC Criteria

April 28, 2026

First Posted (Actual)

May 5, 2026

Study Record Updates

Last Update Posted (Actual)

May 20, 2026

Last Update Submitted That Met QC Criteria

May 18, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • ENCOPER-HCB-2026-001

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Individual participant data (IPD) to be shared includes the anonymized case-level dataset containing: NASA-TLX subscale scores (T1, T2, T3), surgical case characteristics (anesthetic technique, surgical specialty, ASA, duration), and exploratory alarm management variables (VAS, P1, P2, P3). Participant-level data (experience, training) will be included in anonymized form. No directly identifiable information will be shared.

IPD Sharing Time Frame

IPD and supporting documents will be available starting 6 months after publication of the primary results article (estimated 2027-2028) and will remain available for 5 years.

IPD Sharing Access Criteria

IPD will be available upon reasonable request to the principal investigator (vcaro@clinic.cat). Requestors must provide: (1) a brief description of the proposed use, (2) institutional affiliation, and (3) agreement to data use conditions. Data will be shared as anonymized datasets in CSV format. No individual participant can be identified from the shared data.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Performance

Clinical Trials on NASA Task Load Index (NASA-TLX)

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Benin

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe