Usefulness of non-invasive cardiac output monitoring in elderly patients undergoing monopolar transurethral resection of the prostate: a pilot study.

OBJECTIVE: To assess the impact of irrigating fluid on hemodynamic profiles using real-time non-invasive cardiac output monitoring (NICOM) in elderly patients undergoing monopolar transurethral resection of the prostate (TURP). METHODS: Twenty patients between 65 and 80 years of age who were scheduled for monopolar TURP and received spinal anesthesia up to T10 were enrolled. Irrigating fluid (2.7% sorbitol with 0.5% mannitol solution) was used. Hemodynamic profiles including cardiac index, and stroke volume variation (SVV) using NICOM were obtained. Estimated irrigating fluid absorption was indirectly calculated. RESULTS: The median amount of irrigating fluid used was 6000 mL. The median SVV was 11%, which increased to 12% at 10 minutes after initiating surgery. No significant changes in the cardiac index were observed. The estimated absorption of irrigating fluid was almost zero. CONCLUSIONS: Although the estimated amount of irrigating fluid that was absorbed was negligible, the increase in SVV may indicate intravascular volume depletion with diuresis resulting from mannitol in the irrigating fluid early during irrigation. Therefore, even during short irrigating times, intensive hemodynamic monitoring should be performed to monitor the possibility of intravascular volume depletion as well as volume overload, especially immediately after large amounts of irrigating fluid are used.

Comparison of Sufentanil- and Fentanyl-based Intravenous Patient-controlled Analgesia on Postoperative Nausea and Vomiting after Laparoscopic Nephrectomy: A Prospective, Double-blind, Randomized-controlled Trial.

Background: The incidence of postoperative nausea and vomiting (PONV) remains high. The effects of sufentanil for PONV is not firmly confirmed. The aim of this study was to compare the effect of sufentanil- and fentanyl-based intravenous patient-controlled analgesia (IV-PCA) on the incidence of PONV after laparoscopic nephrectomy. Methods: Eighty-six patients were randomly allocated to receive either the sufentanil (n =43) or fentanyl (n =43). IV-PCA was prepared using either sufentanil 3 µg/kg or fentanyl 20 µg/kg, ramosetron 0.3 mg, and ketorolac 120 mg. The primary outcome of was the incidence of PONV during 24 h after post anesthesia care unit (PACU) discharge. The secondary outcomes were the modified Rhodes index and patient satisfaction scores at 24 h after PACU discharge, need for rescue antiemetics, pain score, need for additional analgesics, and cumulative consumption of IV-PCA Results: The incidence of PONV was comparable between the sufentanil and fentanyl groups (64.3% vs. 65%, p = 0.946; respectively). The number of patients who required antiemetics (p = 0.946) and the modified Rhodes index at 24 h after post-anesthesia care unit discharge (p = 0.668) were also comparable in both groups. No significant differences were found in the secondary outcomes, including the analgesic profiles and adverse events between the groups. Conclusions: In conclusion, sufentanil- and fentanyl-based IV-PCA showed similar incidence of PONV with comparable analgesic effects after laparoscopic nephrectomy. Based on these results, we suggest that sufentanil and fentanyl may provide comparable effects for IV-PCA after laparoscopic nephrectomy.

Analgesic effect of trigger point injection and EMLA for shoulder pain in patients undergoing total laparoscopic hysterectomy: A randomized controlled study.

BACKGROUD: The purpose of this study was to evaluate the effects of trigger point injection (TPI) and eutectic mixture local anesthetics (EMLA) cream on the postoperative shoulder pain in patients undergoing total laparoscopic hysterectomy. METHODS: In this randomized, single-blinded, and controlled study, total 75 patients were randomly allocated to TPI group (n = 25), EMLA group (n = 25), and control group (n = 25). TPI group received TPIs with 2 mL of 0.2% ropivacaine, and EMLA group received an occlusive dressing with EMLA cream 2 g on both shoulders. Overall, abdominal, and shoulder pains were evaluated at rest and in motion on postoperative day 3. RESULTS: The incidence of shoulder pain was significantly reduced in EMLA group (56%) compared to control (88%) or TPI (88%) groups (P = .025 in both); the severity of shoulder pain was mitigated in EMLA and TPI groups compared to control group (P < .001, each). Consequently, the overall pain decreased in EMLA group and TPI group (P = .023). The patients with exercise habit (n = 31) showed lower incidence of pain than patients without exercise habit (n = 26) (P = .002, P = .005, and P = .037 in overall, abdominal, and shoulder pain, respectively). TPI or EMLA treatments decreased shoulder pain irrespective of exercise habit (P = .001 and P < .001, respectively), but decreased overall pain only in patients without exercise habit (P = .019). Lastly, EMLA lowered overall pain score at the time of first analgesic request in ward compared to control group (P = .02). CONCLUSIONS: TPI and EMLA with occlusive dressing effectively reduced the shoulder pain after total laparoscopic hysterectomy.

Effect of Combined Treatment of Ketorolac and Remote Ischemic Preconditioning on Renal Ischemia-Reperfusion Injury in Patients Undergoing Partial Nephrectomy: Pilot Study.

We evaluated postoperative renal function in patients with/without combined therapy of ketorolac and remote ischemic preconditioning during partial nephrectomy. Sixteen patients were randomly allocated to either the ketorolac combined with RIPC group (KI, n = 8) or control group (n = 8). The KI group received both remote ischemic preconditioning before surgery and intravenous ketorolac of 1 mg/kg before renal artery clamping. Renal parameters were measured before induction, after anesthesia induction, and 2, 12, 24, 48, and 72 h after renal artery declamping. Acute kidney injury was assessed by Acute Kidney Injury Network criteria. The estimated glomerular filtration rate decreased in both groups, but then increased significantly at 48 h and 72 h after declamping only in the KI group compared to 24 h (p = 0.001 and p = 0.016). Additionally, it was higher at 48 h and 72 h after declamping in the KI group compared to the control group (p = 0.025 and p = 0.044). The incidence of acute kidney injury was significantly reduced in the KI group (13%) compared to the control group (83%) (p = 0.026). FENa was markedly increased at 2 h after declamping, and recovered in both groups, but it was more significant at 12 h after declamping in the KI group (p = 0.022). Urinary N-acetyl-1-ß-D-glucosoaminidase and serum neutrophil gelatinase-associated lipocalin were similar (p = 0.291 and p = 0.818). There is a possibility that combined therapy of ketorolac and remote ischemic preconditioning prior to ischemia may alleviate renal dysfunction and reduce the incidence of acute kidney injury in patients undergoing partial nephrectomy.

Caudal and epidural blocks in infants and small children: historical perspective and ultrasound-guided approaches.

In infants and small children, ultrasound (US) guidance provides ample anatomical information to perform neuraxial blocks. We can measure the distance from the skin to the epidural space in the US image and can refer to it during needle insertion. We may also visualize the needle or a catheter during real-time US-guided epidural catheterization. In cases where direct needle or catheter visualization is difficult, US allows predicting successful puncture and catheterization using surrogate markers, such as dura mater displacement, epidural space widening due to drug injection, or mass movement of the drug within the caudal space. Although many experienced anesthesiologists still prefer to use conventional techniques, prospective randomized controlled trials using US guidance are providing increasing evidence of its advantages. The use of US-guided regional block will gradually become widespread in infants and children.

A randomized comparison of volume- and pressure-controlled ventilation in children with the i-gel: Effects on peak inspiratory pressure, oropharyngeal leak pressure, and gastric insufflation.

BACKGROUND: The i-gel provides good airway sealing but gastric insufflation may occur when peak inspiratory pressure (PIP) exceeds the sealing pressure of the i-gel without a gastric tube. Pressure-controlled ventilation (PCV) provides lower PIP compared with volume-controlled ventilation (VCV) and low PIP may reduce the incidence of gastric insufflation in children during positive pressure ventilation. This study was designed to evaluate PIP, oropharyngeal leak pressure, and gastric insufflation during VCV or PCV in children undergoing general anesthesia with i-gel without a gastric tube in situ. METHODS: A prospective, randomized-controlled study was conducted. Thirty-four children, aged 6 to 84 months, were randomly allocated into the VCV or PCV group. Fiberoptic bronchoscopy was performed to confirm appropriate position of i-gel. Oropharyngeal leak pressure and PIP were measured after i-gel insertion, after caudal block, and after surgery. Ultrasonography was performed to detect gastric insufflation. Gastric tube was not inserted. RESULTS: PIP in cm H2O was significantly lower in the PCV group than in the VCV group after i-gel insertion (10 [9-12] vs 12 [11-15], P = .021), after caudal block (11 [10-12] vs 13 [11-15], P = .014), and after surgery (10 [10-12] vs 13 [11-14], P = .002). There was no difference in the incidence of gastric insufflation between the 2 groups (4/17 in the VCV group and 3/17 in the PCV group) (P > .999). CONCLUSION: When i-gel was used without a gastric tube, gastric insufflation occurred regardless of the ventilation modes, which provided different PIP.

Reference Intervals of Thromboelastometric Evaluation of Coagulation in Pediatric Patients with Congenital Heart Diseases: A Retrospective Investigation.

BACKGROUND Rotational thromboelastometry (ROTEM®) is a point-of-care test for coagulation, enabling physicians to make a swift decision. The aim of this investigation was to establish reference intervals of thromboelastometric evaluation for coagulation in pediatric patients with congenital heart diseases (CHD). MATERIAL AND METHODS As baseline data, 3 assays of ROTEM® (INTEM, EXTEM, and FIBTEM) were measured after anesthesia induction. ROTEM® parameters were clotting time (CT), amplitude at 10 min (A10), clot formation time (CFT), a angle, maximal clot firmness (MCF), clot lysis index at 60 min (LI60), and maximal clot elasticity (MCE). As age is a well-known factor for maturation, age groups were determined as follows; 1) <1 month, 2) 1-3 months, 3) 4-12 months, 4) 1-3 years, 5) 4-6 years, 6) 7-12 years, and 7) 13-16 years. Reference limits representing 95% of distribution of ROTEM® parameters and 90% confidence intervals of upper and lower reference limits were calculated. RESULTS The data of 413 patients were analyzed. Although INTEM CT was prolonged, significantly shorter CT and CFT, steeper α, and greater A10, MCF, and MCE were shown in patients age <3 months compared to older children. CONCLUSIONS Reference intervals of thromboelastometric evaluation for coagulation from pediatric patients with CHD were shown to have similar pattern to those obtained from healthy pediatric patients. Pediatric patients with CHD, even with cyanosis, were demonstrated to have functionally intact coagulation profile before surgery.

Impact of Diabetes Mellitus on Radial and Ulnar Arterial Vasoreactivity after Radial Artery Cannulation: A Randomized Controlled trial.

BACKGROUND: Endothelial dysfunction associated with diabetes mellitus (DM) may influence arterial vasoreactivity after arterial stimulus, such as cannulation, and cause changes in diameter and blood flow. Despite the frequent use of arterial cannulation during anesthesia and critical care, little information is available regarding vasoreactivity of the radial and ulnar arteries and its influence on underlying DM. METHODS: Forty non-DM and 40 DM patients, who required arterial cannulation during general anesthesia, were enrolled. Using duplex Doppler ultrasonography, we measured the patients' arterial diameter, peak systolic velocity, end-diastolic velocity, resistance index, and mean volume flow of both arteries at five different time points. RESULTS: After radial artery cannulation, ulnar arterial diameter and blood flow did not significantly increase in DM group, as they did in non-DM group. Ulnar arterial resistance index significantly increased in both groups, but the degree of decrease in DM group was significantly less than non-DM. CONCLUSION: Ulnar artery's ability to increase blood flow for compensating the sudden reduction of radial arterial flow in DM patients was significantly less than that in non-DM patients under general anesthesia. Such attenuated vasoreactivity of ulnar artery to compensate the reduced radial arterial flow may have to be considered in radial arterial cannulation for DM patients.

Risk Assessment of Mortality Following Intraoperative Cardiac Arrest Using POSSUM and P-POSSUM in Adults Undergoing Non-Cardiac Surgery.

PURPOSE: The Physiological and Operative Severity Score for enUmeration of Mortality and morbidity (POSSUM) and its Portsmouth modification (P-POSSUM) are comprehensive assessment methods for evaluating patient and surgical factors widely used to predict 30-day mortality rates. In this retrospective study, we evaluated the usefulness of POSSUM and P-POSSUM in predicting 30-day mortality after intraoperative cardiac arrests in adult patients undergoing non-cardiac surgery. MATERIALS AND METHODS: Among 190486 patients who underwent anesthesia, 51 experienced intraoperative cardiac arrest as defined in our study protocol. Predicted mortality rates were calculated using POSSUM and P-POSSUM equations and were compared with actual outcomes using exponential and linear analyses. In addition, a receiver operating characteristic curve analysis was undertaken, and area-under-the-curve (AUC) values with confidence intervals (CIs) were calculated for POSSUM and P-POSSUM. RESULTS: Among the 51 patients with intraoperative cardiac arrest, 32 (62.7%) died within 30 days postoperatively. The overall predicted 30-day mortality rates using POSSUM and P-POSSUM were 65.5% and 57.5%, respectively. The observed-to-predicted (O:E) ratio for the POSSUM 30-day mortality was 1.07, with no significant difference between the observed and predicted values (χ²=4.794; p=0.779). P-POSSUM predicted mortality equally well, with an O:E ratio of 1.10 (χ²=8.905; p=0.350). AUC values (95% CI) were 0.771 (0.634-0.908) and 0.785 (0.651-0.918) for POSSUM and P-POSSUM, respectively. CONCLUSION: Both POSSUM and P-POSSUM performed well to predict overall 30-day mortality following intraoperative cardiac arrest in adults undergoing non-cardiac surgery at a university teaching hospital in Korea.

The Effect of 1 µg/kg Dexmedetomidine Combined with High-Volume/Low-Concentration Caudal Ropivacaine in Children Undergoing Ambulatory Orchiopexy.

When local anesthetics are used, the administration of dexmedetomidine (DEX) can prolong analgesic duration. However, the effect of caudal DEX on high volume/low concentration (HVLC) local anesthetics has not been studied. We investigated the analgesic effect of DEX added to a HVLC of ropivacaine for caudal block in children. Eighty children (the American Society of Anesthesiologists (ASA) status I; age, 1-6 years) undergoing ambulatory orchiopexy were enrolled in the study. Children were randomly assigned to undergo a caudal block with 1.5 mL/kg of 0.15% ropivacaine and either 1 µg/kg of DEX (DEX group, n=40) or the same amount of saline (Control group, n=40) under general anesthesia. The results showed that the time to first analgesic request was significantly longer in the DEX group than in the control group. The sevoflurane requirement for anesthesia and frequency of emergence agitation (EA) were also significantly lower in the DEX group. There was no difference in adverse events between the two groups. In conclusion, a dose of 1 µg/kg of caudal DEX prolonged the first analgesic request time, although the immediate postoperative pain scores were comparable in both groups. Furthermore, caudal DEX significantly reduced the sevoflurane requirement and the frequency of EA.

Adequate sedation with single-dose dexmedetomidine in patients undergoing transurethral resection of the prostate with spinal anaesthesia: a dose-response study by age group.

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSION: The single-dose of DMT for light sedation was lower by 21% in Group O compare with Group Y underwent TURP with spinal anesthesia. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01665586. Registered July 31, 2012.

Selective spinal anesthesia using 1 mg of bupivacaine with opioid in elderly patients for transurethral resection of prostate.

PURPOSE: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.

An ultrasound evaluation of laryngeal mask airway position in pediatric patients: an observational study.

BACKGROUND: 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. METHODS: 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. RESULTS: 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%). CONCLUSIONS: Although US could not detect the suboptimal depth of an LMA, US has promise of being an accurate tool in detecting a rotated LMA.

Ultrasound visibility of spinal structures and local anesthetic spread in children undergoing caudal block.

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.

Efficacy of intrathecal morphine combined with intravenous analgesia versus thoracic epidural analgesia after gastrectomy.

PURPOSE: Epidural 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 METHODS: Sixty-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. RESULTS: This 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. CONCLUSION: ITM-IVPCA is not as effective as PCTEA in patients undergoing gastrectomy, with respect to pain control, ambulation, postoperative ileus and pulmonary complications.

Effect of dexmedetomidine on sevoflurane requirements and emergence agitation in children undergoing ambulatory surgery.

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. RESULTS: 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. CONCLUSION: 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.

Effects of incrementally increasing tidal volume on the cross-sectional area of the right internal jugular vein.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Palonosetron has superior prophylactic antiemetic efficacy compared with ondansetron or ramosetron in high-risk patients undergoing laparoscopic surgery: a prospective, randomized, double-blinded study.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: Single-dose palonosetron is the prophylactic antiemetics of choice in high-risk patients undergoing laparoscopic surgery.