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.
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.
Refusal to participate or withdrawal of informed consent.
Spinal anesthesia without sedation.
Exclusive regional anesthesia without sedation.
Sedation alone without regional technique.
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.
Cohort
Prospective
NASA Task Load Index (NASA-TLX)
Other interventionThe 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.
Global Raw NASA-TLX Score
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.
NASA-TLX Subscale Scores
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.
Monitor Alarm Perception Visual Analog Scale (VAS)
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).
Alarm Management Behavior and Attention Interference During Intraoperative Care.
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.
Estimated Percentage of Non-Actionable Monitor Alarms (P1)
Exploratory measure of nurses' perception of non-actionable monitor alarms per surgical case. After patient awakening or sedation reversal, nurses estimate the percentage of alarms that did NOT require immediate clinical action, using four categories: less than 25%, 25-50%, 51-75%, or more than 75%. Used to explore the association between alarm burden and cognitive load (NASA-TLX score). Assessed given the absence of a validated alarm fatigue instrument in Spanish.
Patient Discharge Destination After Surgery
Categorization of the patient's discharge destination at the end of the surgical procedure, as recorded by the anesthesia nurse: Post-Anesthesia Care Unit (PACU/URPA), Intensive Care Unit (ICU), Intermediate Care Unit, or General Ward (Hospitalization). Used as a contextual variable to characterize case complexity and patient severity in relation to cognitive load.
Airway Status at Operating Room Discharge
Categorization of the patient's airway management status at the end of the surgical procedure, as recorded by the anesthesia nurse. Four categories: (1) Endotracheal intubation (ETT) - patient transferred intubated; (2) Extubated - no respiratory support; (3) Extubated with Venturi mask (VMK); (4) Extubated with non-invasive mechanical ventilation (NIV/VMNI). Used as a contextual variable characterizing the clinical complexity of the emergence phase in relation to cognitive load.
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