The concentration of desflurane preventing spectral entropy change during surgical stimulation: A prospective randomized trial.

STUDY OBJECTIVE: To determine the concentration of desflurane necessary to blunt changes in spectral entropy during surgical incision when two different target-controlled effect-site concentrations of remifentanil (1 and 3ng/ml) were infused. DESIGN: Prospective, randomized controlled study. SETTING: Operating room of a university hospital. INTERVENTIONS: Forty-two patients undergoing general anesthesia for elective surgery were enrolled and randomly allocated to the R1 (1ng/ml of remifentanil, n=21) or R3 (3ng/ml of remifentanil, n=21) group. After at least a 10-min administration of target-controlled remifentanil concentration and predetermined end-tidal desflurane following endotracheal intubation, changes in spectral entropy in response to surgical incision were evaluated. MEASUREMENTS: Concentration of desflurane necessary to blunt changes in spectral entropy during surgical incision for each group was determined using Dixon's up-and-down method. Hemodynamic variables including mean arterial pressure (MAP) and heart rate (HR) were measured. MAIN RESULTS: Concentration of desflurane necessary to blunt changes in spectral entropy during surgical incision in 50% of patients (EC50) was 4.1% (95% CI: 3.5-4.7%) for the R1 group and 3.4% (95% CI: 3.0-3.8%) for the R3 group (P=0.033). Additionally, the calculated EC95 values using the logistic regression analysis for the R1 and R3 groups were 5.8% (95% CI: 5.0-10.8%) and 5.1% (95% CI: 4.3-10.6%), respectively. MAPs and HRs were significantly higher in the R1 than in the R3 group after surgical incision. CONCLUSIONS: Desflurane 4.1% with remifentanil 1ng/ml and desflurane 3.4% with remifentanil 3ng/ml significantly blunt the change in spectral entropy after surgical incision in 50% of patients.

Stepwise tapering of remifentanil at the end of surgery decreased postoperative pain and the need of rescue analgesics after thyroidectomy.

BACKGROUND: This study was designed to investigate whether stepwise tapering of remifentanil at the end of surgery could decrease postoperative pain scores and requirements of rescue analgesics after remifentanil-desflurane anesthesia in patients with thyroidectomy. METHODS: Sixty two patients undergoing thyroidectomy under general anesthesia were randomly allocated into two groups. All patients were anesthetised with desflurane and high-dose remifentanil. Remifentnail was infused at the rate of 0.3 µg/kg/min until the end of surgery in patients of the control group (group A) whereas remifentanil was tapered gradually from 0.3 to 0.1 µg/kg/min until the end of surgery for at least 30 minutes in patients with group B. Pain scores (0-100 numerical rating scale, NRS), rescue analgesic requirements and adverse events were assessed at 30 min, 2 h, 6 h, 12 h, and 24 h after operation. RESULTS: There was a significant decrease in pain scores at 30 min (20 [0-80] vs. 50 [0-100], P = 0.002) and 2 h (30 [10-60] vs. 40 [20-80], P = 0.018) after surgery in group B compared with group A. In addition, rescue analgesics are less required in group B than in group A postoperatively (2 [1-3] vs. 3 [2,3], P = 0.039). There were no significant differences in adverse events between the two groups. CONCLUSIONS: Tapering of remifentanil at the end of surgery decreased postoperative pain scores immediately after thyroidectomy with desflurane and high-dose remifentanil anesthesia. TRIAL REGISTRATION: Clinical Research information Service (CRiS, registration number KCT0000589).

The simultaneous application of positive-end expiratory pressure with the Trendelenburg position minimizes respiratory fluctuations in internal jugular vein size.

BACKGROUND: The respiratory cycle alters the size of the right internal jugular vein (RIJV). We assessed the changes in RIJV size during the respiratory cycle in patients under positive pressure ventilation. Moreover, we examined the effects of positive-end expiratory pressure (PEEP) and the Trendelenburg position on respiratory fluctuations. METHODS: A prospective study of 24 patients undergoing general endotracheal anesthesia was performed. Images of the RIJV were obtained in the supine position with no PEEP (baseline, S0) and after applying three different maneuvers in random order: (1) a PEEP of 10 cmH2O (S10), (2) a 10° Trendelenburg tilt position (T0), and (3) a 10° Trendelenburg tilt position combined with a PEEP of 10 cmH2O (T10). Using the images when the area was smallest and largest, cross-sectional area (CSA), anteroposterior diameter, and transverse diameter were measured. RESULTS: All maneuvers minimized the fluctuation in RIJV size (all P = 0.0004). During the respiratory cycle, the smallest CSA compared to the largest CSA at S0, S10, T0, and T10 decreased by 28.3 8.5, 8.0, and 4.4%, respectively. Furthermore, compared to S0, a 10° Trendelenburg tilt position with a PEEP of 10 cmH2O significantly increased the CSA in the largest areas by 83.8% and in the smallest areas by 169.4%. CONCLUSIONS: A 10° Trendelenburg tilt position combined with a PEEP of 10 cmH2O not only increases the size of the RIJV but also reduces fluctuation by the respiratory cycle.

Effect of adjusted cuff pressure of endotracheal tube during thyroidectomy on postoperative airway complications: prospective, randomized, and controlled trial.

BACKGROUND: Postoperative sore throat (POST) is a common complaint after general anesthesia, especially following thyroidectomy. MATERIALS AND METHODS: We examined the effect of adjusting the endotracheal tube cuff pressure during thyroidectomy on the incidence of airway complications. Ninety patients scheduled for elective thyroidectomy were randomized into two groups: control (group A, n = 45) and experimental (group B, n = 45). All patients underwent total intravenous anesthesia with propofol and remifentanil. In group A, the cuff pressure was set to 25 cm H2O initially and then monitored continuously without adjustment during thyroidectomy. In group B, the cuff pressure was maintained at approximately 25 cm H2O throughout the operation. The incidences and the severity of POST, hoarseness, dysphagia, and cough were recorded at 2 and 24 h postoperatively. RESULTS: Cuff pressures in group A changed significantly over time (P < 0.05) and were higher than those of group B during thyroidectomy (P < 0.05). The incidences of POST were lower in group B than in group A at 2 and 24 h postoperatively (P < 0.05), and there was a significant difference in the severity of POST at 2 h postoperatively between the two groups. There were no differences in the incidences of hoarseness, dysphagia, and cough between the two study groups (P > 0.05). Adjusting the endotracheal cuff pressure during thyroidectomy decreased the incidence and degree of POST. CONCLUSIONS: Intraoperative monitoring and adjustment of the cuff pressure can reduce POST in patients undergoing thyroidectomy.

Randomized, controlled trial of multimodal shoulder injection or intravenous patient-controlled analgesia after arthroscopic rotator cuff repair.

PURPOSE: The aim of this study was to compare the effect of postoperative pain control and adverse effects of intravenous patient-controlled analgesia (IV PCA) and multimodal shoulder injection after arthroscopic rotator cuff repair. METHODS: Seventy patients scheduled for elective arthroscopic rotator cuff repair were prospectively randomized to receive either IV PCA or multimodal shoulder injections. Postoperative pain, nausea, vomiting, and other adverse effects were assessed at 2, 6, 12, 24, and 48 h after surgery. Use of rescue analgesics and antiemetics, level of satisfaction, and cost for both modalities were recorded. RESULTS: Pain was better controlled in the multimodal shoulder injection group at 2 h postoperatively (P = 0.001). However, the use of additional analgesics was greater in the multimodal shoulder injection group during 12-48 h after surgery (P < 0.001). The incidence of nausea within 12-24 h after surgery in the multimodal shoulder injection group (5.7 %) was less significant compared with that in the IV PCA group (31.4 %, P = 0.012), but no difference in overall incidence of the use of rescue antiemetics was observed between the groups (n.s.). No differences in adverse effects were noted between the groups. Patient satisfaction also showed no differences (n.s.). Costs required for both modalities were $20.3 for the multimodal shoulder injection and $157.8 for the IV PCA. CONCLUSIONS: Multimodal shoulder injection is a safe and effective modality for management of pain after arthroscopic rotator cuff repair. Considering the expense and need of special devices for IV PCA, multimodal shoulder injection may be an effective and safe alternative to IV PCA for postoperative analgesia after arthroscopic rotator cuff repair.

Effect of airway pressure on lumbar epidural pressure during positive pressure ventilation.

BACKGROUND: The purpose of this study was to measure lumbar epidural pressure (EP) during the insertion of a Tuohy needle under general anesthesia and to evaluate the influence of airway pressure on EP. METHODS: Lumbar EP was measured directly through a Tuohy needle during intermittent positive pressure ventilation in fifteen patients. Mean and peak EP were recorded after peak inspiratory pressures (PIP) of 0, 15, and 25 cmH(2)O. RESULTS: All measured lumbar EPs were positive, with the pressure increasing during inspiration and decreasing during expiration. Median EP was 6.0 mmHg (interquartile range, 4.0-8.0) at 0 cmH(2)O of PIP, 6.5 mmHg (4.5-8.5) at 15 cmH(2)O, and 8.5 mmHg (6.0-10.5) at 25 cmH(2)O, increasing significantly at 15 cm H(2)O PIP, and further increasing at 25 cmH(2)O (P < 0.001). CONCLUSIONS: We demonstrate the influence of increased airway pressure on lumbar EP measured directly through a Tuohy needle. Lumbar EPs were positive, and increasing PIP levels significantly increased lumbar EP.

Spreading pattern of contrast medium in the high thoracic epidural space in rabbits: the effect of neck flexion and extension.

BACKGROUND: Neck flexion has been shown to increase cranial spread of contrast agent when a small fixed volume was injected into the high thoracic epidural space. The purpose of this study was to evaluate the effect of volume of contrast medium on its distribution through the high thoracic epidural space during neck extension and flexion using the rabbit model. METHODS: An epidural catheter was introduced into the epidural space of New Zealand white rabbits with the tip located at the T3-4 intervertebral level. The neck was extended or flexed (n = 8 for each group), and the contrast medium was injected with the volume increasing by increments of 0.1 ml/kg, up to 0.3 ml/kg. The spread of contrast medium was determined by counting the number of vertebral body units using lateral epidurographic images. RESULTS: In both groups, the total spread of contrast medium was similar, increasing continuously with injected volume. The cranial spread was greater in the flexion group than the extension group. However, the caudal spread was greater in the extension than in the flexion group. In the extension group, the contrast medium spread caudally about twice as far as it spread cranially, but there was no statistically significant difference between cranial and caudal spread in the flexion group. CONCLUSIONS: In the high thoracic epidural space of rabbit, the contrast medium of varying doses showed limited cranial spread. The flexion of the neck increased cranial spread and extension of the neck increased caudal spread.

A survey on informed consent process for epidural analgesia in labor pain in Korea.

BACKGROUND: There is a legal obligation to explain the procedure and use of epidural analgesia in labor primarily due to the possibility of potential risks and associated complications. The present study details on the survey carried out to ascertain the current status of obtaining informed consent (IC) for explaining the epidural analgesia in labor. METHODS: The present study is based on a survey through a telephone questionnaire that covered all the hospitals in Korea where the anesthesiologists' belonged to and are registered with Korean Society of Anesthesiologists. The questionnaire included questions pertaining to administration of epidural analgesia to a parturient, information on different steps of obtaining an IC, whether patient status was evaluated, when the consent was obtained, and the reasons behind, if the consent had not being given. RESULTS: A total of 1,434 respondents took part in the survey, with a response rate of 97% (1,434/1,467). One hundred seventy-four hospitals had conducted epidural analgesia on the parturient. The overall rate of obtaining IC for epidural analgesia during labor was 85%, of which only 13% was conducted by anesthesiologists. The rate of evaluating preoperative patient status was 74%, of which 45% was conducted by anesthesiologists. Almost all of the consent was obtained prior to the procedure. CONCLUSIONS: The rate of obtaining IC for epidural analgesia in labor is relatively high (85%) in Korea. However, it is necessary to discuss the content of the consent and the procedure followed for obtaining IC during the rapid progress of labor.

Dental caries prevalence of medieval Korean people.

OBJECTIVES: Prevalence and distribution of dental caries in medieval Korean society were evaluated. MATERIALS AND METHODS: Two thousand and nine hundred teeth samples of 126 individuals collected from 16th to 18th century Korean tombs. RESULTS: Preservation status of sample was good. The prevalence of ante- and postmortem tooth loss was 4.4% and 14.2%, respectively. The total caries prevalence was 3.9%. The tooth surface most frequently affected by dental caries was occlusal (4.5%), followed by approximal (2.1%), buccal (1.5%), and lingual (1.1%) surfaces. DISCUSSION: The prevalence of dental caries in Joseon Dynasty skeleton collection was lower than have been found in other collections of similar chronology. The low consumption of refined sugar in medieval Korean society might be a possible explanation, though the technical limitations inherent in such comparison studies preclude definitive conclusions.

Does skin temperature difference as measured by infrared thermography within 6 months of acute herpes zoster infection correlate with pain level?

BACKGROUND: Changes in the temperature distribution of the skin follows herpes zoster (HZ). Infrared thermography is a non-invasive, non-ionizing diagnostic tool that provides information about normal and abnormal functioning of the sensory and sympathetic nervous systems. This study examined the usefulness of infrared thermography as a predictor of post-herpetic neuralgia (PHN). METHODS: Infrared thermography was performed on the affected body regions of 110 patients who had been diagnosed with acute HZ. Demographic data collected included age, gender, time of skin lesions onset, development of PHN, and comorbidities. The temperature differences between the unaffected and affected dermatome were calculated. Differences >0.6 degrees C for the mean temperature across the face and trunk were considered abnormal. RESULTS: The affected side was warmer in 35 patients and cooler in 33 patients than the contralateral side. A patient's age and disease duration affected treatment outcomes. However, the temperature differences were not correlated with pain severity, disease duration, allodynia, development of PHN, and use of antiviral agents (P>0.05). CONCLUSION: A patient's age and disease duration are the most important factors predicting PHN progression, irrespective of thermal findings, and PHN cannot be predicted by infrared thermal imaging.

Laparoscopic cholecystectomy under epidural anesthesia: a clinical feasibility study.

BACKGROUND: Laparoscopic cholecystectomy (LC) has traditionally been performed under general anesthesia, however, owing in part to the advancement of surgical and anesthetic techniques, many laparoscopic cholecystectomies have been successfully performed under the spinal anesthetic technique. We hoped to determine the feasibility of segmental epidural anesthesia for LC. METHODS: Twelve American Society of Anesthesiologists class I or II patients received an epidural block for LC. The level of epidural block and the satisfaction score of patients and the surgeon were checked to evaluate the efficacy of epidural block for LC. RESULTS: LC was performed successfully under epidural block, with the exception of 1 patient who required a conversion to general anesthesia owing to severe referred pain. There were no special postoperative complications, with the exception of one case of urinary retention. CONCLUSIONS: Epidural anesthesia might be applicable for LC. However, the incidence of intraoperative referred shoulder pain is high, and so careful patient recruitment and management of shoulder pain should be considered.