How Personality Type Affects Pain and the Need for General Anesthesia in Patients Receiving an Arm Nerve Block for Wrist Fracture Surgery

This prospective observational study evaluates the association between affective temperament profiles and perioperative anesthetic outcomes in adult patients undergoing elective upper extremity surgery under ultrasound-guided axillary brachial plexus block.

Affective temperament was assessed preoperatively using the validated TEMPS-A (Temperament Evaluation of Memphis, Pisa, Paris, and San Diego - Autoquestionnaire). Based on established scoring methodology, participants were categorized into depressive, anxious, cyclothymic, hyperthymic, irritable, or non-dominant temperament types. The instrument is grounded in Akiskal's affective temperament model, which conceptualizes temperament as a stable trait influencing stress reactivity, emotional processing, and physiological responses.

All patients received a standardized anesthetic protocol. Ultrasound-guided axillary brachial plexus block was performed with identification of the radial, median, ulnar, and musculocutaneous nerves. A total of 20 mL of 0.25% bupivacaine was administered. Intravenous fentanyl (50 µg) was given prior to block placement. Intraoperative discomfort was managed with supplemental sedation. Conversion to general anesthesia was performed when regional anesthesia alone was insufficient to maintain surgical conditions. Block failure was defined as inability to complete the procedure using the regional technique alone.

Hemodynamic parameters (systolic blood pressure, diastolic blood pressure, mean arterial pressure, and heart rate) were recorded at baseline and at 5-minute intervals during surgery. Postoperative pain intensity was measured using the Visual Analog Scale at predefined perioperative time points.

Statistical analyses included correlation testing and multivariable modeling. LASSO regression was applied for variable selection and identification of predictors of increased postoperative pain scores. Ridge logistic regression was used to determine independent predictors of anesthesia escalation, accounting for multicollinearity among baseline hemodynamic variables and temperament types.

This study explores whether stable affective traits influence regional anesthesia adequacy, intraoperative physiological responses, and postoperative pain perception, with the aim of informing individualized perioperative management strategies.

Inclusion criteria

• Age between 18 and 65 years
• Scheduled for elective upper extremity surgery requiring axillary brachial plexus block
• American Society of Anesthesiologists (ASA) physical status I-III
• Ability to understand and complete the TEMPS-A questionnaire
• Provision of written informed consent

Exclusion criteria

• Refusal to participate
• Contraindication to regional anesthesia (e.g., local infection at injection site, coagulopathy)
• Known allergy to local anesthetics (bupivacaine)
• Cognitive impairment or inability to complete the temperament questionnaire
• Severe psychiatric disorder requiring active treatment
• Incomplete perioperative data or missing VAS assessments