The study included a total of 80 patients aged 20–65 years with ASA 1–2 scores on the American Society of Anesthesiologists (ASA) physical status classification and who were electively scheduled for EUS under sedation in the endoscopy unit. All EUS procedures included in the study were diagnostic. EUS requiring invasive procedures was excluded. The inclusion criteria were as follows: educational background and mental status sufficient to be able to fill out the scales and surveys intended for assessment, no psychiatric or neurological disorders, no use of psychiatric medications or alcohol consumption, and no significant cardiovascular, respiratory, or liver diseases. Eighty of 98 patients who underwent EUS during the 3-month study period met the criteria. Approval for the study was obtained from the Bezmialem Vakif University Medical Faculty Clinical Research Ethics Board (approval no. 71306642-050.01.04). The study was conducted according to the Helsinki Declaration of 1964 and its later amendments and the International Association for the Study of Pain (IASP) guidelines for pain research in animals and humans. The investigators personally and thoroughly informed all participants of the study’s aims and structure. Patients were informed that participation was voluntary and anonymous, and would not affect their care. Informed consent for participation in the study was obtained from each patient.
Patients were instructed to fill out the STAI and PSQ forms that they were given for preoperative assessment before the procedure. Patients received a detailed explanation of each form and completed the forms in a quiet room. The patients were educated on the scoring of the visual analog scale (VAS, 0–10) for postoperative pain evaluation.
Assessment of Anxiety
Spielberger's STAI used in the measurement of anxiety consists of two parts. State anxiety (STAI-S) assesses the state of anxiety depending on the intensity of the current emotional event affecting anxiety. Trait anxiety (STAI-T) assesses more persistent anxiety, which is stable over time and is not affected by the intensity of momentary emotional states . The STAI has been translated into Turkish and its reliability and validity confirmed by Oner and Le Compte .
Assessment of Pain Sensitivity
The PSQ was developed by Ruscheweyh et al. to assess pain sensitivity . It is a non-invasive, easy, and reliable survey that assesses pain sensitivity by imagining painful situations occurring in everyday life. The PSQ is a self-administered rating of pain sensitivity and was found to yield results similar to the pain sensitivity assessed by experimental methods . The PSQ is based on the rating of 17 different painful conditions in everyday life on an 11-point scale (0 = no pain; 10 = the most severe pain). It can be completed within 5–10 min. Three items (5, 9, 13) describe situations that are not normally considered painful by healthy individuals (for example, taking a hot shower) and are not included in the total score. In addition to the PSQ total score, two other scores, i.e., PSQ minor pain score and PSQ moderate pan score, were also created. These two sub-scores were defined by factor analysis in the previous study . PSQ minor includes seven cases that cause minor pain (mean score of < 4 on the 11-point scale), and the PSQ moderate includes seven other cases causing moderate pain (mean score of 4–6 on the 11-point scale). The PSQ total score was calculated as the average score of items 1, 2, 3, 4, 6, 7, 8, 10, 11, 12, 14, 15, 16, and 17 (excluding three painless cases). The PSQ minor score was calculated as the average score of items 3, 6, 7, 10, 11, 12, and 14, and the PSQ moderate score was calculated as the average score of items 1, 2, 4, 8, 15, 16, and 17.
All patients were taken into the procedure room without premedication prior to the procedure. Basal values of heart rate (HR), systolic arterial pressure, diastolic arterial pressure, oxygen saturation (SpO2), and respiratory rate were measured in patients who were under standard monitoring. Vascular access was established through a 20-gauge IV catheter.
A bispectral index (BIS; Aspect Medical Systems/Covidien, MA, USA) was used for monitoring to measure the depth of anesthesia . During BIS measurements, patients were asked to close their eyes and not to speak or move. Noncommissioned personnel in the procedure room were asked to leave the room, and unnecessary lights were switched off .
All patients were given oxygen through a nasal cannula at a dose of 2 L min−1 starting from the beginning of sedation. For sedation, 0.03 mg kg−1 midazolam, 1 mg kg−1 lidocaine, 1 µ kg−1 fentanyl, and then a bolus dose of 1 mg kg−1 propofol were administered intravenously using an infusion pump over 60 s. The elapsed time until the BIS value reached 75 was recorded. For maintenance of the anesthesia, 2 mg kg−1 h−1 propofol infusion was started. Medium-deep sedation was ensured with a BIS value of 65–75 during the procedure . In the case of sedation failure, an additional dose of 0.1 mg kg−1 of propofol (IV) was administered, and the propofol infusion was halted once the BIS value dropped below 65.
The total duration of the procedure, the total amount of propofol consumed during this time, and the number of additional doses of propofol needed were recorded.
Potential cardiopulmonary conditions and the interventions performed were recorded. Intravenous administration of 0.001 mg kg−1 atropine was planned in the event of bradycardia (HR < 50 min−1), while reduction of propofol dosage, 0.9% isotonic fluid loading, and intravenous administration of 5 mg ephedrine as needed were planned in the case of hypotension (systolic arterial pressure < 80 mmHg), and increasing oxygen flow, lifting the jaw, discontinuation of propofol, stopping the procedure, and implementing mask ventilation if necessary were planned in the event of hypoxia (SpO2 < 90%) development.
The patients were taken to the recovery unit for monitoring once their hemodynamics were appropriate following the completion of the procedure. Eligibility for transfer from the recovery room to the service was assessed using the Aldrete recovery score (ARS). The duration of stay in the recovery room until reaching an ARS score of 9 was recorded; patients with an ARS score of 9 were sent to their services. The numeric rating scale was used for postoperative nausea and vomiting, while the visual analog scale (VAS, 0–10) was used for postoperative pain assessment. VAS was assessed at 1 h and 2 h. In the case of a VAS value of ≥ 4, 20 mg kg−1 paracetamol was administered intravenously. All data were recorded.
Intraoperative and postoperative parameters were assessed by an independent anesthesiologist who was blinded to the assessment of preoperative anxiety and pain sensitivity.
The Statistical Package for the Social Sciences version 22.0 (IBM Corporation, Armonk, NY, USA) program was used for the statistical analysis. Descriptive values of the obtained data were calculated as mean ± SD, number, and frequency in percentage. The independent-samples t-test was used to compare the two sexes in terms of STAI-S, STAI-T, PSQ minor, PSQ moderate, and PSQ total scores. Relations between preoperative anxiety and pain sensitivity levels and other numerical clinical and sociodemographic characteristics were examined using Pearson’s correlation analysis. A value of p < 0.05 was considered as indicating statistical significance.
The sample size was calculated using simple random sampling from the study population, which identified a total of 98 patients, and the required values were substituted in the formula and yielded a minimum number of 78 patients for adequate statistical power [n = (98)(1.96)2(0.5)(0.5)/ (0.05)2(98–1) + (1.96)2(0.5)(0.5)] (p = 0.5 is considered).