This study looked at whether a person's emotional personality type affects how they experience pain and how well a regional anesthesia technique works during arm surgery.

We studied patients who underwent wrist or upper arm surgery using an axillary nerve block (a type of regional anesthesia that numbs the arm). Before surgery, patients completed a questionnaire measuring their emotional temperament, including anxious, depressive, cyclothymic, irritable, and other personality traits.

We found that patients with an anxious personality type were more likely to need conversion to general anesthesia during surgery. They also reported higher pain scores after surgery. Patients with depressive traits also experienced higher pain levels. In contrast, some other temperament types reported lower pain levels.

These findings suggest that emotional characteristics may influence how patients respond to anesthesia and pain after surgery. Understanding a patient's temperament before surgery may help doctors better plan anesthesia, provide additional support when needed, and improve overall comfort and safety.

This research supports a more personalized approach to anesthesia care, taking into account not only physical health but also psychological factors.

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

The study population consists of adult patients undergoing elective upper extremity surgery at Kırşehir Ahi Evran University Training and Research Hospital, a tertiary academic medical center in Turkey. Participants were recruited from patients evaluated in the preoperative anesthesia outpatient clinic and scheduled to receive ultrasound-guided axillary brachial plexus block as the primary anesthetic technique.

Individual participant data will not be made publicly available. De-identified data may be made available from the corresponding author upon reasonable request, subject to institutional and ethical approval.