[Show abstract][Hide abstract] ABSTRACT: This study was to evaluate the characteristics of selective spinal anesthesia using 1 mg of bupivacaine combined with fentanyl or sufentanil in elderly patients undergoing transurethral resection of prostate.
Fifty-six patients were randomized into two groups. The Fentanyl group received 0.5% hyperbaric bupivacaine 0.2 mL+fentanyl 20 μg+5% dextrose 1.4 mL, and the Sufentanil group received 0.5% hyperbaric bupivacaine 0.2 mL+sufentanil 5 μg+5% dextrose 1.7 mL intrathecally. Intraoperative and postoperative characteristics were evaluated. Patient satisfaction was assessed postoperatively.
Twenty-six patients in each group completed the study. The median peak sensory block level was similar between two groups, but sensory regression time was longer in the Sufentanil group than the Fentanyl group (p=0.017). All patients were able to move themselves to the bed without any aid when they arrived at the admission room. Pain scores were lower in the Sufentanil group than the Fentanyl group at postoperative 6, 12, and 18 hours (p=0.001). Compared to the Fentanyl group, the Sufentanil group required less postoperative analgesia (p=0.023) and the time to the first analgesic request was longer (p=0.025). Twenty-four of 26 patients (92.3%) in each group showed "good" satisfaction level.
Selective spinal anesthesia using 1 mg of bupivacaine with fentanyl or sufentanil provided appropriate sensory block level with spared motor function for transurethral resection of the prostate in elderly patients. Intrathecal sufentanil was superior to fentanyl in postoperative analgesic quality.
Yonsei Medical Journal 03/2015; 56(2):535-42. DOI:10.3349/ymj.2015.56.2.535 · 1.26 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Dexmedetomidine (DMT), a highly selective α2-adrenoceptor agonist, has been used safely as a sedative in patients under regional anesthesia. The purpose of this study was to determine the 50% effective dose (ED50) of single-dose DMT to induce adequate light sedation in elderly patients in comparison with younger patients undergoing transurethral resection of the prostate (TURP) with spinal anesthesia.
Forty-two male patients were recruited. The young age group (Group Y) included patients 45 to 64 years old and the old age group (Group O) included patients 65 to 78 years old. After the spinal anesthesia was performed, a pre-calculated dose of DMT was administered for 10 min. The Observer's Assessment of Alertness/Sedation (OAA/S) scale, bispectral index score (BIS) were assessed then at 2-min intervals for 20 min. A modified Dixon's up-and-down method was used to determine the ED50 of the drug for light sedation (OAA/S score 3/4). In the recovery room, regression times of the motor and sensory blocks were recorded.
The ED50 of DMT was 0.25 (95% C.I. 0.15-0.35) μg/kg in Group O and 0.35 (95% C.I. 0.35-0.45) μg/kg in Group Y (p = 0.002). The ED95 was 33% lower in Group O compare with Group Y (0.38 (95% C.I. 0.29-0.39) μg/kg vs. 0.57 (95% C.I. 0.49-0.59) μg/kg). The regression time of sensory block was longer in Group O than in Group Y (109.0 ± 40.2 min vs. 80.0 ± 31.6 min) (p = 0.014).
The single-dose of DMT for light sedation was lower by 21% in Group O compare with Group Y underwent TURP with spinal anesthesia.
ClinicalTrials.gov identifier: NCT01665586 . Registered July 31, 2012.
[Show abstract][Hide abstract] ABSTRACT: In children, the laryngeal mask airway (LMA) is frequently displaced within the hypopharynx, resulting in repositioning of the device. When the tip of the LMA is placed in the esophageal inlet, the arytenoids are moved ventrally. When the LMA is rotated or deviated, the ventral movement of the arytenoids may result in asymmetric elevation of an arytenoid cartilage, which can be detected with ultrasound (US). In this study, we sought to estimate the incidence of LMA malposition detected with US in pediatric patients. The primary end point was to compare the incidence of LMA malposition between US and fiber optic bronchoscopy (FOB). The secondary end points were to find the interrelationship between US-detected and FOB-detected malposition of the LMA and to locate the diagnostic performance of US in detecting LMA malposition.
In this observational study, 100 consecutive children were included. After anesthetic induction, US evaluation was performed before and after LMA insertion to obtain the glottic image on the anterior neck. FOB was performed to assess LMA position (FOB LMA grade and LMA rotation grade). With a post-LMA US image, the symmetry of the arytenoid cartilages was evaluated. Asymmetrical elevation of an arytenoid cartilage in reference to the glottic midline and the opposite arytenoid cartilage was graded as 0 to 3 (US arytenoid grade). The interrelationships between US arytenoid grade and FOB LMA grade or LMA rotation grade were assessed.
The incidence of asymmetrical elevation of an arytenoid was 50% (95% confidence interval [CI], 40%-60%). On FOB, the incidence of LMA malposition was 78% (95% CI, 69%-86%), and that of LMA rotation was 43% (95% CI, 33%-53%). The incidence of LMA malposition was higher with FOB (P < 0.0001), but the incidence of rotation was similar (P = 0.395). US arytenoid grade did not correlate with FOB LMA grade (P = 0.611) but showed a significant correlation with LMA rotation grade (P < 0.0001; 95% CI, 60%-83%). To detect a rotated LMA, US had a sensitivity of 93% (95% CI, 81%-98%) and a specificity of 82% (95% CI, 70%-91%). The positive and negative predictive values were 80% (95% CI, 66%-90%) and 94% (95% CI, 83%-99%), respectively. The accuracy was 87% (95% CI, 79%-93%).
Although US could not detect the suboptimal depth of an LMA, US has promise of being an accurate tool in detecting a rotated LMA.
[Show abstract][Hide abstract] ABSTRACT: This study assessed ultrasound visibility of spinal structures in children and observed the extent of local anesthetic spread within the epidural space during caudal block. Spinal structures were evaluated with ultrasound from the sacral area to the thoracic area in 80 children, and drug spread levels were observed after caudal injection of 0.5, 1.0, 1.25 and 1.5 mL/kg local anesthetic. The conus medullaris, dural sac and dura mater were easily identified with ultrasound in most children. However, ligamentum flavum visibility declined with increasing vertebral level and markedly decreased at the thoracic level in children older than 7 mo or heavier than 8.5 kg. Drug spread was higher with increasing volume (p < 0.001) and in children ≤12 mo more than children >12 mo (p < 0.001); drug spread was significantly correlated with age (R(2) = 0.534). Spread levels assessed with ultrasound were roughly two to three segments lower than those in previous radiologic studies.
Ultrasound in Medicine & Biology 09/2014; 40(11). DOI:10.1016/j.ultrasmedbio.2014.06.020 · 2.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: PurposeEpidural analgesia has been the preferred analgesic technique after major abdominal surgery. On the other hand, the combined use of intrathecal morphine (ITM) and intravenous patient controlled analgesia (IVPCA) has been shown to be a viable alternative approach for analgesia. We hypothesized that ITM combined with IVPCA is as effective as patient controlled thoracic epidural analgesia (PCTEA) with respect to postoperative pain control after conventional open gastrectomy.Materials and MethodsSixty-four patients undergoing conventional open gastrectomy due to gastric cancer were randomly allocated into the intrathecal morphine combined with intravenous patient-controlled analgesia (IT) group or patient-controlled thoracic epidural analgesia (EP) group. The IT group received preoperative 0.3 mg of ITM, followed by postoperative IVPCA. The EP group preoperatively underwent epidural catheterization, followed by postoperative PCTEA. Visual analog scale (VAS) scores were assessed until 48 hrs after surgery. Adverse effects related to analgesia, profiles associated with recovery from surgery, and postoperative complications within 30 days after surgery were also evaluated.ResultsThis study failed to demonstrate the non-inferiority of ITM-IVPCA (n=29) to PCTEA (n=30) with respect to VAS 24 hrs after surgery. Furthermore, the IT group consumed more fentanyl than the EP group did (1247.2±263.7 µg vs. 1048.9±71.7 µg, p<0.001). The IT group took a longer time to ambulate than the EP group (p=0.021) and had higher incidences of postoperative ileus (p=0.012) and pulmonary complications (p=0.05) compared with the EP group.ConclusionITM-IVPCA is not as effective as PCTEA in patients undergoing gastrectomy, with respect to pain control, ambulation, postoperative ileus and pulmonary complications.
Yonsei Medical Journal 07/2014; 55(4):1106-14. DOI:10.3349/ymj.2014.55.4.1106 · 1.26 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Purpose
Dexmedetomidine, a potent selective α2-adrenergic agonist, produces sedation and analgesia. This study was conducted to assess the effect of dexmedetomidine infusion on sevoflurane requirements, recovery profiles, and emergence agitation in children undergoing ambulatory surgery.
Materials and Methods
Forty children undergoing ambulatory hernioplasty or orchiopexy were randomized into two groups. The dexmedetomidine group (Group D, n=20) received dexmedetomidine 1 µg/kg, followed by 0.1 µg/kg/h until the end of surgery, whereas the saline group (Group S, n=20) received volume-matched normal saline. Sevoflurane was used for induction and maintenance of anesthesia and caudal block was performed in all children. End-tidal sevoflurane concentration (ET-sevo), the incidence of emergence agitation, pain scores, and sedation scores were recorded. Hemodynamic changes and other adverse effects were assessed in the perioperative period.
ET-sevo of Group D was significantly reduced in 23.8-67% compared to Group S during surgery. The incidence of emergence agitation was lower in Group D than in Group S (5% vs. 55%, p=0.001). Postoperative pain was comparable, and discharge time was not different between the groups. Mean arterial pressure and heart rate were significantly lower in Group D during surgery.
Intraoperative infusion of dexmedetomidine reduced sevoflurane requirements and decreased emergence agitation without delaying discharge in children undergoing ambulatory surgery. However, caution should be taken in regard to bradycardia and hypotension.
Yonsei medical journal 01/2014; 55(1):209-15. DOI:10.3349/ymj.2014.55.1.209 · 1.26 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Different tidal volume (TV) settings during mechanical ventilation alter intrathoracic blood volume, and these changes could alter central venous pressure and the cross sectional area (CSA) of the right internal jugular vein (RIJV). The aim of this study was to determine the optimal TV for maximizing the CSA of the RIJV in the supine and Trendelenburg positions in anesthetized patients.
Forty patients were randomly allocated to a supine group (Group S, n = 20) or a Trendelenburg group (Group T, n = 20) by computer generated randomization. RIJV CSAs were measured repeatedly after increasing the inspiratory volume in 1 ml/kg increments from a TV of 8 ml/kg to 14 ml/kg using ultrasound images.
Peak inspiratory pressure increased significantly on increasing TV from 11 ml/kg to 14 ml/kg and between baseline (TV 8 ml/kg) and 11 ml/kg in both groups (P < 0.05). RIJV CSA was not increased versus baseline even after TV changes in either group and no intergroup difference was found.
TV increases do not increase the CSA of the RIJV within the TV range 8 to 14 ml/kg in the supine or 10° Trendelenburg position.
Korean journal of anesthesiology 10/2013; 65(4):312-6. DOI:10.4097/kjae.2013.65.4.312
[Show abstract][Hide abstract] ABSTRACT: The appropriate endotracheal tube (ETT) size is commonly determined using age-based formula; ETT size determination based on ultrasound (US) measurement of subglottic diameter (SD), the narrowest portion of the paediatric upper airway, may provide a better method for accurate fit. We aimed to validate ETT size determination using US measures of SD before intubation to establish an empirical formula for ETT fitting based on SD and biographic parameters.
We included 215 children aged 1-72 months undergoing general anaesthesia. US was performed on the anterior neck to measure SD during mask ventilation under anaesthesia. Endotracheal intubation was performed with a cuffed ETT selected by age-based recommendation; the transverse outer diameter (OD) of the ETT within the trachea at the subglottis level (OD-ETT at SD) was measured.
The OD-ETT at SD was correlated with the actual OD-ETT outside the trachea (R(2) = 0.635), showing the validity of ultrasonographic measurement; moreover, the US-measured SD revealed strong correlation with the actual OD-ETT (R(2) = 0.834). US-measured SD and biographic data (age, height and weight) showed little correlation in children less than 12 months but good correlation (age, height) in children older than 12 months (P < 0.01).
US-measured OD-ETT at SD was in good agreement with the actual OD-ETT, suggesting that US-measured SD helps in choosing the appropriate ETT diameter for children. In children older than 12 months, the equation 'OD (mm) = 0.01 × age (months) + 0.02 × height (cm) + 3.3' may help select the appropriate ETT.
[Show abstract][Hide abstract] ABSTRACT: Postoperative nausea and vomiting (PONV) continues to be a major problem, because PONV is associated with delayed recovery and prolonged hospital stay. Although the PONV guidelines recommended the use of 5-hydroxy-tryptamine (5-HT3) receptor antagonists as the first-line prophylactic agents in patients categorized as high-risk, there are few studies comparing the efficacies of ondansetron, ramosetron, and palonosetron. The aim of present study was to compare the prophylactic antiemetic efficacies of three 5HT3 receptor antagonists in high-risk patients after laparoscopic surgery.
In this prospective, randomized, double-blinded trial, 109 female nonsmokers scheduled for elective laparoscopic surgery were randomized to receive intravenous 4 mg ondansetron (n = 35), 0.3 mg ramosetron (n = 38), or 75 µg palonosetron (n = 36) before anesthesia. Fentanyl-based intravenous patient-controlled analgesia was administered for 48 h after surgery. Primary antiemetic efficacy variables were the incidence and severity of nausea, the frequency of emetic episodes during the first 48 h after surgery, and the need to use a rescue antiemetic medication.
The overall incidence of nausea/retching/vomiting was lower in the palonosetron (22.2%/11.1%/5.6%) than in the ondansetron (77.1%/48.6%/28.6%) and ramosetron (60.5%/28.9%/18.4%) groups. The rescue antiemetic therapy was required less frequently in the palonosetron group than the other groups (P < 0.001). Kaplan-Meier analysis showed that the order of prophylactic efficacy in delaying the interval to use of a rescue emetic was palonosetron, ramosetron, and ondansetron.
Single-dose palonosetron is the prophylactic antiemetics of choice in high-risk patients undergoing laparoscopic surgery.
Korean journal of anesthesiology 06/2013; 64(6):517-23. DOI:10.4097/kjae.2013.64.6.517
[Show abstract][Hide abstract] ABSTRACT: Low-dose bupivacaine can limit the spinal block level with minimal hemodynamic effects and yield a rapid recovery, but sometimes it may not provide adequate anesthesia for surgery. Dexmedetomidine, a selective α2-adrenoreceptor agonist, was shown to be a potent antinociceptive agent when given intrathecally in animals and humans. The purpose of this study was to evaluate the adjuvant effects of intrathecal dexmedetomidine in elderly patients undergoing transurethral prostate surgery with low-dose bupivacaine spinal anesthesia. Fifty-four patients undergoing transurethral prostate surgery were randomized into two groups receiving either dexmedetomidine 3 µg (n=27) or normal saline (n=27) intrathecally with 6 mg of 0.5% hyperbaric bupivacaine. The characteristics of the spinal block and postoperative analgesic effects were evaluated. The peak block level was similar for the two groups. However, the dexmedetomidine group demonstrated a faster onset time to the peak block and longer duration of spinal block than the saline group (p<0.01). The motor block scales at the time of peak sensory block and regression of 2-sensory dermatomes were higher in the dexmedetomidine group than in the saline group (p<0.001). There was less analgesic request and the time to the first analgesic request was longer in the dexmedetomidine group than in the saline group (each 487, 345 min, p<0.05). Dexmedetomidine 3 µg when added to intrathecal bupivacaine 6 mg produced fast onset and a prolonged duration of sensory block and postoperative analgesia in elderly patients for transurethral surgery. However, recovery of motor block could be delayed in dexmedetomidine-added patients.
[Show abstract][Hide abstract] ABSTRACT: This prospective, randomized, and observer-blinded study was performed to evaluate the effects of oral chloral hydrate on perioperative psychological and behavioral phenomena in children.
In total, 100 boys (age, 1-5 years) scheduled for day-case unilateral orchiopexy were randomly allocated into 2 groups and orally administered either 40 mg/kg of chloral hydrate (CH group) or placebo (control group) 30 minutes before surgery, followed by assessment of anxiety, induction compliance, emergence delirium, postoperative pain, and maladaptive behavioral changes.
Anxiety scores were significantly lower in the CH group compared with the control group (45.7 vs 28.8). The induction compliance of the CH group was better than that of the control group (3.2 vs 4.8). Postoperative sedation was more frequent (62.7% vs 20.4%); however, the incidence of vomiting was lower (2.0% vs 14.3%) in the CH group than in the control group. Postoperative emergence delirium and maladaptive behavior changes were similar between the 2 groups.
Decreasing preoperative anxiety with oral chloral hydrate improves induction compliance and reduces postoperative pain intensity without delaying recovery in young boys. However, chloral hydrate had little impact on emergence delirium and postoperative maladaptive behavior.
Journal of Pediatric Surgery 08/2012; 47(8):1592-9. DOI:10.1016/j.jpedsurg.2011.12.025 · 1.31 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study evaluated ulnar and radial artery blood flow after radial artery cannulation during general anaesthesia using Doppler ultrasound. A total of 80 patients were randomly assigned to receive radial artery cannulation with either a 20-G or 22-G cannula. Arterial diameter, peak systolic velocity, end-diastolic velocity, resistance index and mean volume flow were measured at four time points in both arteries: before anaesthesia; 5 min after intubation; immediately after cannulation; and 5 min after cannulation. After radial artery cannulation, ulnar diameters and blood flow were significantly increased, and persisted until 5 min after cannulation. Radial blood flow was decreased immediately after cannulation and recovered to pre-cannulation values 5 min after cannulation. There were no statistical differences between groups at each time point. Radial artery cannulation causes compensatory increase in ulnar artery blood flow, and the difference in cannula size has minimal effect on this change.
[Show abstract][Hide abstract] ABSTRACT: To justify the use of the lidocaine/tetracaine medicated patch or peel as a preventive treatment for reducing pain and discomfort in adults and children. We reviewed randomized controlled trials (RCTs) to evaluate the efficacy and safety of the lidocaine/tetracaine medicated patch or peel compared with placebo.
Ten RCTs (574 patients) were included in this systemic review. Relevant studies were identified through searches of MEDLINE, SCOPUS and the Cochrane database library. The outcome was the adequacy of cutaneous anesthesia reflected in the patient's assessment of pain intensity during minor dermatologic procedures and adverse effects after application of the lidocaine/tetracaine medicated patch or peel versus placebo.
The efficacy of the lidocaine/tetracaine patch or peel was consistently very significantly beneficial 30 or 60 minutes after the application compared to placebo (Relative risk, RR: 2.5; Number needed to treat, NNT: 2.2). We did not identify any difference in the effectiveness of adequate analgesia between the lidocaine/tetracaine patch and peel (the number needed to treat or to harm, NNT 2.4 vs. 2.0). No serious side effects or adverse events were observed with the lidocaine/tetracaine medicated patch or peel and placebo. Minor skin reactions were transient and resolved without treatment (Odd ratio, OR: 1.4 and 95% confidence interval, CI: 0.9-2.1; NNT: 14.9).
The lidocaine/tetracaine medicated patch or peel is a well accepted, effective and safe method for minor dermatologic procedures based on pooled data of trials in terms of adequacy of cutaneous anesthesia and adverse effects.
Korean journal of anesthesiology 05/2012; 62(5):435-40. DOI:10.4097/kjae.2012.62.5.435
[Show abstract][Hide abstract] ABSTRACT: Dexmedetomidine (DMT) has been shown to prolong spinal anaesthesia. We evaluated the effects of intravenous DMT on low-dose bupivacaine spinal anaesthesia in elderly patients.
Fifty-one elderly patients undergoing transurethral resection of the prostate were randomized into two groups receiving either 1.0 μg/kg DMT (DMT group, n = 26) or normal saline (control group n = 25) intravenously prior to spinal anaesthesia with 1.2 ml of bupivacaine, 5 mg/ml.
The mean time to two-segment regression (39 min vs. 78 min for cold, 41 min vs. 61 min for pinprick) and that to motor regression (23 min vs. 46 min) were longer in the DMT group than in the control group. The atropine-requiring bradycardia was more frequent in the DMT group than in the control group (24.0% vs. 3.8%). The median sedation scores (ranges) during surgery were 4 (2-6) in the DMT group and 2 (1-3) in the control group (P < 0.001). Two patients in the DMT group showed oxygen desaturation (peripheral oxygen saturation < 90%) during surgery. The duration of post-operative care unit stay was longer in the DMT group than in the control group (58 min vs. 96 min). Post-operative pain intensity was lower and the mean time to first request for post-operative analgesia was longer in the DMT group compared to the control group (6.6 h vs. 2.1 h).
Intravenous DMT prolonged the duration of spinal anaesthesia and improved post-operative analgesia. However, more profound sedation with desaturation was observed with more frequent bradycardia, and delayed recovery should be considered in elderly patients.
[Show abstract][Hide abstract] ABSTRACT: Spinal block induces hyperkinetic change in lower extremity blood flow. We compared the venous flow dynamic responses to spinal block in normotensive and hypertensive elderly patients.
Following spinal block using 10 mg 0.5% (w/v) bupivacaine, we measured changes in blood pressure, heart rate, and venous flow dynamics of the popliteal vein by duplex ultrasonography in 20 normotensive (NBP group) and 18 hypertensive (HIBP group) patients.
Spinal block caused significant decreases in blood pressure in both groups; similar rates of hypotension were observed. At baseline, peak velocity, time-averaged maximum velocity, and time-averaged mean velocity were higher in the HIBP than in the NBP group. During spinal block, peak velocity increased in both groups, and the between-group differences were no longer significant. At baseline, volume flow in the two groups was similar and increased by 141.5% in the NBP and 131.7% in the HIBP group during spinal block.
Blood pressure and flow dynamics in the popliteal vein showed similar changes during spinal anaesthesia in elderly patients taking antihypertensive medication and normotensive patients, despite differences in baseline values.
[Show abstract][Hide abstract] ABSTRACT: Lower spinal dysraphism is frequently reported in anorectal anomaly combined with urogenital anomalies. The prevalence of the spinal dysraphism has not been comprehensively studied in children with simple urogenital anomalies. We evaluated the prevalence of the spinal dysraphism using ultrasound data of the lumbosacral area in children with urogenital anomalies.
Lumbosacral ultrasound images of 259 children who underwent urological surgery with simple urogenital anomalies were reviewed by an ultrasound-specialized radiologist. The primary outcome measures were the conus medullaris (CM) level and the thickness of the filum terminale. The spinal ultrasonographic findings that were assessed in children showed abnormal spinal findings compared with the other children having normal findings. Two years later, the follow-up telephone interviews were made with the parents of the children with abnormal findings.
Eighteen children were differentiated as the abnormal finding group. They were suspected of spinal cord tethering. The level of CM was lower, and the filum terminale was thicker compared to the normal group [L2(lower (L)) vs. L1(L), 2.2 mm vs. 0.8 mm]. Of eighteen children, four were confirmed as tethered spinal cord with lipoma on magnetic resonance imaging by the time of surgery, and two were strongly suspected of occult spinal dysraphism (OSD) based on ultrasound findings and follow-up interviews.
The prevalence of OSD in children under 24 months of age with simple urogenital anomaly was higher than what was reported for the general population. Ultrasound examination of spinal structures before caudal block in children with urogenital anomaly should be considered.
[Show abstract][Hide abstract] ABSTRACT: Psychological factors are thought to drive inter-patient variations in anaesthetic and analgesic requirements. This cross-sectional study investigated whether preoperative psychological factors can predict anaesthetic requirements and postoperative pain.
Before total thyroidectomy, 100 consecutive women completed the Spielberger's State-Trait Anxiety Inventory (STAI) and the pain sensitivity questionnaire (PSQ). Target-controlled propofol was administered for induction of anaesthesia, and sevoflurane-oxygen-air was given to maintain equal depths of anaesthesia, as determined by bispectral index (BIS) monitoring.
Patients with higher anxiety scores (state and trait) required greater amounts of propofol to reach light (BIS=85) and moderate (BIS=75) levels of sedation, but only trait anxiety was significantly associated with propofol requirements in reaching a deep level of sedation (BIS=65). The MAC-hour of sevoflurane was significantly correlated only with PSQ scores. The postoperative pain intensity was significantly correlated with both STAI and PSQ.
Preoperative anxiety and pain sensitivity are independent predictors of propofol and sevoflurane requirements in general anaesthesia. Anaesthetic and analgesic doses could be modified based on the patient's preoperative anxiety and pain sensitivity.
BJA British Journal of Anaesthesia 11/2011; 108(1):119-25. DOI:10.1093/bja/aer305 · 4.35 Impact Factor