Development of the Geop-Pain questionnaire for multidisciplinary assessment of pain sensitivity.

BACKGROUND: To assess the multidisciplinary aspects of pain, various self-rating questionnaires have been developed, but there have not been sufficient relevant studies on this topic in South Korea. The aim of this study was to develop a new pain sensitivity-related questionnaire in the Korean language that would be simple and would well reflect Koreans' senses. METHODS: A new pain assessment questionnaire was developed through a pre-survey on "geop", which is the Korean word expressing fear, anxiety, or catastrophizing. We named the new assessment questionnaire the Geop-Pain Questionnaire (GPQ). The GPQ was composed of 15 items divided into three categories and rated on a 5-point scale. As a preliminary study, internal consistency and test-retest reliability analyses were conducted. Subsequently, 109 individuals completed the GPQ along with three pain-related questionnaires translated into Korean (Pain Sensitivity Questionnaire [PSQ], Pain Anxiety Symptoms Scale [PASS], and Pain Catastrophizing Scale [PCS]), and the correlations were analyzed. RESULTS: All items in the GPQ showed appropriate internal consistency, and the test-retest reliability analysis showed no statistically significant differences. The correlations between the GPQ and the existing questionnaires revealed that the GPQ scores had mid-positive correlations with the PSQ scores and strong positive correlations with the PASS and PCS scores. CONCLUSIONS: This study attempted to develop a questionnaire assessing pain sensitivity multidimensionally using the Korean word geop for the first time. The self-rating GPQ showed high correlations with the existing questionnaires and demonstrated potential to be utilized as a pain prediction index in clinical practice.

A Pilot Study of the Correlation between the Numeric Rating Scale used to Evaluate "Geop" and Questionnaires on Pain Perception.

BACKGROUND: The word "geop" is a unique Korean term commonly used to describe fright, fear and anxiety, and similar concepts. The purpose of this pilot study is to examine the correlation between the Numeric Rating Scale (NRS) score of geop and three different questionnaires on pain perception. METHODS: Patients aged 20 to 70 years who visited our outpatient pain clinics were evaluated. They were requested to rate the NRS score (range: 0-100) if they felt geop. Next, they completed questionnaires on pain perception, in this case the Korean version of the Pain Sensitivity Questionnaire (PSQ), the Pain Catastrophizing Scale (PCS), and the Pain Anxiety Symptoms Scale (PASS). The correlations among each variable were evaluated by statistical analyses. RESULTS: There was no statistically significant correlation between the NRS score of geop and the PSQ score (r = 0.075, P = 0.5605). The NRS score of geop showed a significant correlation with the PCS total score (r = 0.346, P = 0.0063). Among the sub-scales, Rumination (r = 0.338, P = 0.0077) and Magnification (r = 0.343, P = 0.0069) were correlated with the NRS score of geop. In addition, the NRS score of geop showed a significant correlation with the PASS total score (r = 0.475, P = 0.0001). The cognitive (r = 0.473, P = 0.0002) and fear factors (r = 0.349, P = 0.0063) also showed significant correlations with the NRS score of geop. CONCLUSIONS: This study marks the first attempt to introduce the concept of "geop." The NRS score of geop showed a moderate positive correlation with the total PCS and PASS score. However, further investigations are required before the "geop" concept can be used practically in clinical fields.

Effects of prophylactic ramosetron and ondansetron on corrected QT interval during general anesthesia.

STUDY OBJECTIVE: To evaluate whether ramosetron increases the corrected QT (QTc) interval. DESIGN: Prospective, randomized, controlled study. SETTING: Operating room. PATIENTS: 135 patients undergoing elective laparoscopic cholecystectomy. INTERVENTION: Patients were allocated to three groups to receive ondansetron 4 mg (Group O4), ramosetron 0.3 mg (Group R), or ondansetron 8 mg (Group O8). The study drugs were administered intravenously approximately 15 minutes before the end of surgery. MEASUREMENT: The QT interval for 10 minutes after administration was recorded. The QTc interval was calculated according to the Fridericia (QTcF) formula. The primary outcome was the QTcF interval among the three groups during the 10 minutes after administration of the study drugs. MAIN RESULTS: The QTcF interval was not significantly prolonged after administration of ondansetron 4 mg and ramosetron. It was significantly increased from one minute after administration until 7 minutes after ondansetron 8 mg (Group O8). The QTcF interval was significantly longer in Group O8 at 1, 2, 3, 4, and 5 minutes. CONCLUSIONS: The prophylactic administration 0.3 mg of ramosetron does not increase the QTc interval. Ondansetron 8 mg increases the QTc interval more so than 4 mg of ondansetron.

The Effect of Low-dose Ketamine on Post-caesarean Delivery Analgesia after Spinal Anesthesia.

BACKGROUND: Ketamine, an N-methyl-D-aspartate receptor antagonist, might play a role in postoperative analgesia, but its effect on postoperative pain after caesarean section varies with study design. We investigated whether the preemptive administration of low-dose intravenous ketamine decreases postoperative opioid requirement and postoperative pain in parturients receiving intravenous fentanyl with patient-controlled analgesia (PCA) following caesarean section. METHODS: Spinal anesthesia was performed in 40 parturients scheduled for elective caesarean section. Patients in the ketamine group received a 0.5 mg/kg ketamine bolus intravenously followed by 0.25 mg/kg/h continuous infusion during the operation. The control group received the same volume of normal saline. Immediately after surgery, the patients were connected to a PCA device set to deliver 25-µg fentanyl as an intravenous bolus with a 15-min lockout interval and no continuous dose. Postoperative pain was assessed using the cumulative dose of fentanyl and visual analog scale (VAS) scores at 2, 6, 24, and 48 h postoperatively. RESULTS: Significantly less fentanyl was used in the ketamine group 2 h after surgery (P = 0.033), but the difference was not significant at 6, 12, and 24 h postoperatively. No significant differences were observed between the VAS scores of the two groups at 2, 6, 12, and 24 h postoperatively. CONCLUSIONS: Intraoperative low-dose ketamine did not have a preemptive analgesic effect and was not effective as an adjuvant to decrease opioid requirement or postoperative pain score in parturients receiving intravenous PCA with fentanyl after caesarean section.

Effect of epidural magnesium on the incidence of chronic postoperative pain after video-assisted thoracic surgery.

OBJECTIVE: The aim of this study was to determine whether the epidural administration of magnesium during the perioperative period decreased the incidence of chronic postoperative pain (CPOP) at 3 months after video-assisted thoracic surgery. DESIGN: Prospective, randomized, and blinded. SETTING: A university hospital. PARTICIPANTS: Patients. INTERVENTIONS: Before the induction of anesthesia, the patients were assigned randomly to receive normal saline, 5 mL, (group C, n = 72) or magnesium sulfate, 100 mg (group M, n = 72), epidurally. At the end of surgery, group C received a continuous infusion of a mixture of 0.2% ropivacaine, 226 mL, and fentanyl, 1,200 µg, through a patient-controlled epidural analgesia pump for 48 hours. In group M, magnesium sulfate, 500 mg, was added to the infusion. MEASUREMENTS AND MAIN RESULTS: The incidence and severity of CPOP were assessed by a telephone survey 3 months after surgery. Patients were asked whether they experienced pain and to rank the severity of the pain using a 3-point scale (1, mild; 2, moderate; 3, severe). The incidences of CPOP were 42.4% in group C and 49.1% in group M. The severities of pain in the patients with CPOP were 1.0 (1-2) in group C and 1.0 (1-2) in group M. The incidence and severity of CPOP did not differ between the 2 groups. CONCLUSIONS: The epidural administration of magnesium from before the induction of anesthesia to 48 hours postoperatively did not decrease significantly the incidence or severity of CPOP in patients undergoing video-assisted thoracic surgery.

Quadriceps muscle rupture mimicking lumbar radiculopathy.

STUDY DESIGN: Case report. OBJECTIVE: To report an unusual case of vastus lateralis muscle rupture not accompanied by any history of major trauma or the presence of a risk factor in a patient with spinal stenosis. Isolated vastus lateralis muscle rupture without an obvious cause is very rare. Localized pain and claudication are the most common symptoms and can be misdiagnosed as lumbar radiculopathy. METHODS: A 70-year-old patient presented with right lower extremity and back pain, diagnosed as spinal stenosis. He was initially treated with caudal epidural block and transforaminal epidural block, which resulted in nearly complete relief of his symptoms. However, he subsequently experienced a pain that was no longer responsive to treatment. The ultrasonographic exam revealed a partial tear of the right vastus lateralis muscle. RESULT: Injection of local anesthetics relieved the patient's symptoms. At 1-month follow-up, he remained pain-free. CONCLUSIONS: In patients with lower back and leg pain, physicians should consider non-spinal conditions that can cause signs and symptoms mimicking lumbar radiculopathy.

A questionnaire study investigating the prevalence of chronic postoperative pain.

BACKGROUND: Chronic postoperative pain (CPOP) is defined as pain of at least 2 months duration after a surgical procedure. Until recently, it has been a neglected topic, because it can occur after a wide spectrum of operations; however, little is known regarding its underlying mechanism, prevalence, risk factors, and treatments. We investigated characteristics of CPOP after various operations via a questionnaire. METHODS: Patients were contacted at > 2 months after surgery, irrespective of sex, type of operation or anesthesia method, and a follow-up pain questionnaire was administered by phone. RESULTS: One hundred forty-five of 400 patients (36.3%) described CPOP. The prevalence of CPOP was significantly lower in laparoscopic surgery (29/159, 18.2%) than open surgery (116/241, 48.1%). The prevalence of CPOP was higher with the use of PCA (patient controlled analgesia), (45.3%) than without PCA (24.6%). There were no significant differences regarding sex, anesthetic method, or duration of operation. CONCLUSIONS: Our results indicate that the prevalence of CPOP may be related to use of an endoscope and PCA. However, it is difficult to completely explain the correlation, because this is a complex area of research. More research is needed to improve the quality of pain relief.

Ropivacaine for ultrasound-guided interscalene block: 5 mL provides similar analgesia but less phrenic nerve paralysis than 10 mL.

PURPOSE: Interscalene brachial plexus block (interscalene block) complications usually depend on the dose administered. The objective of this study was to determine whether ultrasound-guided interscalene block with a 5-mL dose of 0.75% ropivacaine would have sufficient analgesic efficacy after shoulder arthroscopic surgery when compared with a 10-mL dose. METHODS: Patients undergoing arthroscopic rotator cuff repair surgery (n = 60) were assigned randomly to one of two groups receiving 5 mL (Group 5) or 10 mL (Group 10) of 0.75% ropivacaine. Ultrasound-guided interscalene block was performed using the in-plane technique, and general anesthesia was administered. Time to first analgesic request was recorded, and the following issues were assessed in the postanesthesia care unit at six, 12, 24, and 48 hr postoperatively: postoperative pain as determined by a visual analogue scale (VAS), patient satisfaction, hemidiaphragmatic paralysis, other block-related complications, and postoperative nausea and vomiting (PONV). RESULTS: There was no significant difference between groups in time to first analgesic requirement (median [interquartile range] for Group 5: 16 [12-48] hr, Group 10: 18 [12-48] hr; P = 0.907). The postoperative pain VAS score was similar in both groups. The incidence of hemidiaphragmatic paralysis on postoperative chest x-ray was 33% in Group 5 and 60% in Group 10 (P = 0.035). However, the incidences of other block-related complications, PONV, and patient satisfaction were not significantly different between groups. CONCLUSION: Interscalene block performed under ultrasound guidance with 0.75% ropivacaine 5 mL showed analgesic efficacy similar to that with 0.75% ropivacaine 10 mL, but with a lower incidence of hemidiaphragmatic paralysis.

The effect of target-controlled infusion of low-dose ketamine on heat pain and temporal summation threshold.

PURPOSE: We investigated the heat pain threshold (HPT) and temporal summation threshold (TST) before and after target-controlled infusion (TCI) of ketamine with an effect-site concentration (Ce) of 30 and 60 ng/ml. METHODS: Healthy young volunteers (n = 20) were enrolled. A thermode was applied to the volar side of each volunteer's right forearm, and HPT and TST were measured before and after TCI of ketamine. Vital signs and psychedelic effects according to ketamine infusion were also observed before and after TCI of ketamine. RESULTS: Mean HPT after TCI of ketamine with a Ce of 30 and 60 ng/ml did not increase significantly. However, mean TST after TCI of ketamine with a Ce of 30 and 60 ng/ml increased significantly, in a dose-dependent fashion, compared with the value before ketamine TCI. Vital signs showed no significant difference before and after ketamine TCI. The visual analog scale score of psychedelic symptoms was higher with a Ce of 60 ng/ml than with 30 ng/ml. CONCLUSIONS: TCI of ketamine with a Ce of 30 and 60 ng/ml increased TST but not HPT.

A comparison of sufentanil and fentanyl for patient-controlled epidural analgesia in arthroplasty.

BACKGROUND: The use of lipid soluble opioids such as fentanyl, alfentanil and sufentanil are recently on the increase for patient-controlled epidural analgesia (PCEA). In this study, the effects and adequate dose of sufentanil in arthroplasty were investigated. METHODS: Eighty patients scheduled for arthroplasty were enrolled for the study. Seventy-one patients (ASA physical status I-III) were randomly allocated into four groups. All groups received 0.1% ropivacaine through PCEA and each group received either fentanyl (group F: fentanyl 4 µg/ml) or sufentanil (group S1: sufentanil 0.5 µg/ml, group S2: sufentanil 0.75 µg/ml, and group S3: sufentanil 1.0 µg/ml). Postoperative pain scores were evaluated using VAS (visual analog scale, 0-10) and side effects such as hypotension, nausea/vomiting, pruritus and the degree of satisfaction were evaluated at 1, 6, 12, 24, 48 hours after surgery. RESULTS: Postoperative pain score (VAS) decreased gradually and the highest VAS score was recorded at 1 hour postoperative for all four groups. There were no differences in the degree of satisfaction and postoperative pain score between all groups. The incidence of pruritus was significantly lower in group S1 than in groups S2 and S3. CONCLUSIONS: The incidence of side effects were significantly lower in group S1 (0.1% ropivacaine plus sufentanil 0.5 µg/ml). Therefore, 0.5 µg/ml of sufentanil through PCEA is the recommended dose for postoperative pain control in arthroplasty.

Application of triamcinolone acetonide paste to the endotracheal tube reduces postoperative sore throat: a randomized controlled trial.

PURPOSE: This study was performed to examine whether applying triamcinolone acetonide paste as a lubricant to endotracheal tubes (ETTs) reduces the incidence and severity of postoperative sore throat (POST) more effectively than applying chlorhexidine gluconate jelly. METHODS: This was a randomized controlled clinical trial. Patients enrolled in the study were ages 20 to 70 yr, American Society of Anesthesiologists' physical status I and II, and scheduled for elective laparoscopic cholecystectomy. The patients were divided randomly into two groups, the chlorhexidine group and the triamcinolone group. Prior to endotracheal intubation, ETTs in the chlorhexidine group were lubricated with 0.1% chlorhexidine gluconate jelly, whereas the ETTs in the triamcinolone group were lubricated with 0.1% triamcinolone acetonide paste 0.5 mg. During the 24 hr after the operation, we recorded the incidence and severity of POST and the incidence of cough, hoarseness, dysphagia, nausea, and dry throat. RESULTS: Of the 150 patients initially enrolled, 143 patients were included in the study. The incidence of POST was significantly lower in the triamcinolone group compared with the chlorhexidine group (difference = 52.4%; 95% confidence interval, 36.8% to 64.2%; P < 0.001). The severity score for the triamcinolone group was significantly lower than that for the chlorhexidine group. The frequencies of coughing, hoarseness, dysphagia, nausea, and dry throat were similar in the two groups for the first 24 hr after surgery. CONCLUSIONS: Triamcinolone acetonide paste applied along the length of the ETT resulted in clinically important and statistically significant decreases in the incidence and severity of POST compared with the application of chlorhexidine jelly. (ClinicalTrials.gov number, NCT00908817).

Prophylactic effect of dexamethasone in reducing postoperative sore throat.

BACKGROUND: This study was performed to compare the effectiveness of prophylactic dexamethasone and postintubation dexamethasone in reducing the incidence and severity of postoperative sore throat (POST). METHODS: This was a prospective, randomized, double-blind clinical trial. The study population consisted of 70 patients between 20 and 60 years old who were classified as American Society of Anesthesiologists I-II and were scheduled for elective laparoscopic cholecystectomy. The patients were divided randomly into two groups. Patients in the prophylactic and postintubation groups received intravenous injection of 10 mg of dexamethasone 30 min before or after tracheal intubation, respectively. The patients were interviewed 1, 6, and 24 h after the operation. The incidence and severity of POST were recorded. RESULTS: The severity scores of POST at 1 and 6 h after the operation were significantly lower in the prophylactic group than in the postintubation group. There were no significant differences in the incidence of POST during the 24 h after the operation between the two groups (22/32 in the prophylactic group vs. 27/34 in the postintubation group, P = 0.403). CONCLUSIONS: Intravenous injection of 10 mg of dexamethasone was more effective in reducing the severity of POST when administered before tracheal intubation compared with after tracheal intubation.

Thyroid surgery under monitored anesthesia care (MAC).

BACKGROUND: Thyroid surgery is usually performed under general anesthesia, but thyroid surgery under monitored anesthesia care (MAC) has become re-introduced. We report our experiences of 40 cases of thyroid surgery under MAC. METHODS: Forty patients were enrolled in this study. Bilateral superficial cervical plexus block (BSCPB) was performed by using 1% mepivacaine with 1 : 200,000 epinephrine. After BSCPB, patients were sedated with propofol and fentanyl. Postoperative pain, sore throat, hoarseness, and postoperative nausea and vomiting (PONV) were assessed. RESULTS: Mean postoperative pain VAS were 1.3, 1.2, 1.0, 0.8 and postoperative sore throat VAS 1.4, 1.4, 1.1, 0.9 at PACU (post-anesthesia care unit) and postoperative 3, 6, 12 h, respectively. The incidence of hoarseness was 25, 5, 2.5%, and 0% and PONV were 0, 5, 10%, and 7.5% at PACU and postoperative 3, 6, 12 h, respectively. CONCLUSIONS: Thyroid surgery under MAC may be a suitable alternative to general anesthesia.

The effect of rocuronium on heart rate variability in diabetic patients.

BACKGROUND: Clinically rocuronium, a muscle relaxant, has no significant inhibitory effect on the autonomic nervous system in the healthy population. However, there has been no study done on rocuronium in diabetic patients. Therefore, we used heart rate variability (HRV) as a biomarker to investigate cardiac autonomic function after rocuronium administration to diabetic patients. METHODS: In 21 diabetic adult patients, heart rate (HR), mean arterial blood pressure (BP), low frequency (LF, 0.04-0.15 Hz) power, high frequency (HF, 0.15-0.4 Hz) power, LF/HF ratio, SD1 and SD2 in the Poincare plot before induction of anesthesia, and immediately before and after rocuronium administration were calculated and compared. RESULTS: HR, mean BP, LF, LF/HF ratio and SD2 after rocuronium administration did not differ significantly from the measurements taken before rocuronium administration. HF and SD1 decreased significantly after rocuronium administration (P = 0.022, P = 0.019 respectively). Covariates such as age, gender, weight, duration of diabetes mellitus and hypertension did not alter the effect of rocuronium on the autonomic nervous system. CONCLUSIONS: Rocuronium produced a significant decrease in parasympathetic activity. Therefore, further study will be needed to determine whether vagal reduction caused by rocuronium could have potential to deteriorate hemodynamics in diabetic patients.

The effects of epidural magnesium on postoperative pain management in patients with patient-controlled epidural analgesia after a thoracotomy.

BACKGROUND: Magnesium presents analgesic effects by blocking the non-competitive N-methyl-D-aspartate receptor in the spinal cord. The purpose of this study was to evaluate the effects of epidural magnesium on cumulative dose of ropivacaine in patients with patient-controlled epidural analgesia (PCEA) after a thoracotomy. METHODS: In a randomized, prospective, double-blind trial, we enrolled 40 patients undergoing PCEA after a thoracotomy. Control group (n = 20) received an initial dose of 0.375% ropivacaine 0.1 ml/kg, and following demand doses of 0.2% ropivacaine 2 ml with 15 min lockout interval on the patient demand. Magnesium group (n = 20) additionally received MgSO4 100 mg in the initial dose and 4 mg in the demand doses. Cumulative dose of ropivacaine, the resting and coughing visual analog scale (VAS) score were measured at 3, 6, 12, 24, and 48 hours after surgery. RESULTS: Magnesium group showed lower cumulative dose of ropivacaine than control group at 12, 24, and 48 hours after the surgery (P<0.05), but not at 3 and 6 hours (P < 0.05). The VAS score was not different between 2 groups (P < 0.05). CONCLUSIONS: Epidural magnesium may be useful as an adjuvant to ropivacaine after a thoracotomy. However, because magnesium showed no beneficial effect at the early period after the surgery, more investigation about proper initial dose is required.

Epidural tezampanel, an AMPA/kainate receptor antagonist, produces postoperative analgesia in rats.

BACKGROUND: We evaluated the epidural administration of tezampanel, a non-N-methyl-d-aspartate receptor antagonist, in a rat model for postoperative pain. We sought to determine if this drug affects nociception when administered epidurally by testing its effects on responses to heat in normal rats. The effects of epidural tezampanel on pain-related behaviors in rats that underwent plantar incision were also studied. METHODS: Rats were anesthetized and epidural catheters were placed. One day after epidural catheterization, the baseline heat withdrawal latency was measured. Epidural tezampanel or morphine was tested for analgesia by examining their effects against heat withdrawal latency. Motor function was also tested. Comparisons to subcutaneous drug administration were made. Other rats underwent plantar incision after epidural catheterization to assess pain behavior caused by incision. The effects of epidural tezampanel on the cumulative pain scoring, based on guarding, the withdrawal threshold to von Frey filament application, and the withdrawal latency to heat, were measured. The effects of epidural tezampanel on arterial blood pressure and heart rate were also tested. RESULTS: Both epidural morphine and epidural tezampanel increased withdrawal latency to heat. Only subcutaneous morphine affected heat withdrawal latency. After plantar incision, epidural tezampanel decreased the median guarding pain score, increased the heat withdrawal latency and increased the mechanical withdrawal threshold indicating analgesic effects. Arterial blood pressure and heart rate did not change after epidural drug administration. CONCLUSION: These experiments demonstrate that epidural administration of tezampanel produces analgesia to heat, motor side effects in some rats, and reduces pain behaviors caused by incision. No systemic analgesia was apparent using the largest dose.