Intraoperative Cognitive Load in Anesthesia Nurses Across Anesthetic Phases

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.

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.

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).

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.

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.

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.

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.

Categorization of the patient's neurological and behavioral status at discharge from the operating room, as recorded by the anesthesia nurse. Only assessed for extubated patients. Four categories: (1) Awake and cooperative; (2) Awake and agitated; (3) Drowsy / Partial emergence; (4) No emergence / Unresponsive. Used as a contextual variable characterizing the clinical complexity of the T3 phase in relation to cognitive load.

Operational classification of each surgical case data collection record, assessed by the investigator: (1) Complete - all three NASA-TLX phases (T1, T2, T3) and alarm management variables were collected; (2) Incomplete - one or more phases were not collected due to clinical circumstances but the case is included in partial analyses; (3) Drop-out - the case is excluded from all analyses, with the reason documented (e.g., intraoperative emergency, protocol deviation, participant withdrawal). Used to track data quality and guide the missing data management strategy.