Jong Wook Song

The effect of combining dexamethasone with ondansetron for nausea and vomiting associated with fentanyl-based intravenous patient-controlled analgesia*

We investigated whether combined dexamethasone and ondansetron is more effective than ondansetron alone in preventing postoperative nausea and vomiting in patients with fentanyl‐based intravenous patient‐controlled analgesia. One hundred and thirty patients undergoing video‐assisted thoracoscopic surgery were assigned to either an ondansetron group or a dexamethasone and ondansetron group. In all patients, ondansetron 4 mg was administered at the end of surgery and 12 mg was added to the patient‐controlled analgesia solution. The dexamethasone and ondansetron group received dexamethasone 8 mg at the induction of anaesthesia. The overall incidence of nausea and vomiting during the first 48 h postoperatively did not differ between groups (34/61 (56%) vs 28/62 (45%) in the ondansetron group and dexamethasone and ondansetron groups, respectively). The incidence of severe nausea and vomiting (≥ 7 nausea on an 11‐point verbal numerical rating scale, retching or vomiting) was higher in the ondansetron group than in the dexamethasone and ondansetron group (15/61 (25%) vs 6/62 (10%, respectively, p = 0.028). Combined dexamethasone and ondansetron is more effective in reducing severe nausea and vomiting than ondansetron alone in patients receiving fentanyl‐based intravenous patient‐controlled analgesia.

ORIGINAL ARTICLE: Optimal effect-site concentration of remifentanil for preventing cough during emergence from sevoflurane-remifentanil anaesthesia*

This randomised, double‐blinded, controlled trial was designed to identify the optimal dose of remifentanil for cough suppression without adverse effects during emergence from sevoflurane‐remifentanil anaesthesia for thyroidectomy. One hundred and four patients were randomly assigned to maintain target effect‐site concentrations of remifentanil at 0 (control group), 1.0 (remifentail 1 group), or 1.5 ng.ml−1 (remifentanil 1.5 group) during emergence. The incidence of coughing was lower in the remifentanil 1.5 group (31%) than in the control group (74%) or remifentanil 1 group (63%) (p = 0.0004). In addition, the severity of coughing during extubation was lower in the remifentanil 1.5 group (median (IQR [range]) 0 (0–1 [0–1]) than in the control group (1 (0–2 [0–3])) and remifentanil 1 group (1 (0–2 [0–3])) (p = 0.004). Haemodynamic changes were reduced, but emergence time and stay in the post‐anaesthesia care unit was prolonged in the remifentanil 1.5 group. Maintaining the remifentanil effect‐site concentration at 1.5 ng.ml−1 during emergence from sevoflurane‐remifentanil anaesthesia reduces the incidence and severity of coughing without serious adverse events and may provide haemodynamic stability in patients undergoing thyroidectomy. However, awakening may be delayed.

Combination of pregabalin and dexamethasone for postoperative pain and functional outcome in patients undergoing lumbar spinal surgery: A randomized placebo-controlled trial

Objectives:In this randomized-controlled study, we investigated the effects of combined administration of pregabalin and dexamethasone on postoperative pain and analgesic requirements, and functional outcome in patients who underwent lumbar spinal surgery. Methods:One hundred eight patients were randomized to group C (placebo+placebo), group P (pregabalin+placebo), or group PD (pregabalin+dexamethasone). According to their allocated group, patients received placebo or pregabalin 150 mg every 12 hours starting 1 hour before anesthetic induction for a total of 8 doses. Dexamethasone 16 mg or normal saline was injected before the induction of anesthesia. The pain intensity, analgesic requirements, and side effects were assessed in the postoperative period: postanesthesia care unit, 12, 24, 48, and 72 hours. Pain intensity and daily activity performance were also assessed 1, 3, and 6 months after surgery. Results:Compared with group C, the pain scores were lower in group PD at 24 hours after surgery (P=0.011). The frequency of additional rescue analgesic administration was significantly lower in group PD until 48 hours after surgery (P<0.05) and in group P at 24 to 48 hours (P=0.005) relative to group C. Back pain intensity at work was lower (P=0.048) and daily activity performance was better (P=0.006) in group PD compared with group C at 1 month after surgery. Conclusions:Combined administration of pregabalin and dexamethasone conferred analgesic benefits superior to those of pregabalin alone. This regimen also helped facilitate return to normal daily activity after surgery.

Optimal effect-site concentration of remifentanil for preventing cough during emergence from sevoflurane-remifentanil anaesthesia

This randomised, double‐blinded, controlled trial was designed to identify the optimal dose of remifentanil for cough suppression without adverse effects during emergence from sevoflurane‐remifentanil anaesthesia for thyroidectomy. One hundred and four patients were randomly assigned to maintain target effect‐site concentrations of remifentanil at 0 (control group), 1.0 (remifentail 1 group), or 1.5 ng.ml−1 (remifentanil 1.5 group) during emergence. The incidence of coughing was lower in the remifentanil 1.5 group (31%) than in the control group (74%) or remifentanil 1 group (63%) (p = 0.0004). In addition, the severity of coughing during extubation was lower in the remifentanil 1.5 group (median (IQR [range]) 0 (0–1 [0–1]) than in the control group (1 (0–2 [0–3])) and remifentanil 1 group (1 (0–2 [0–3])) (p = 0.004). Haemodynamic changes were reduced, but emergence time and stay in the post‐anaesthesia care unit was prolonged in the remifentanil 1.5 group. Maintaining the remifentanil effect‐site concentration at 1.5 ng.ml−1 during emergence from sevoflurane‐remifentanil anaesthesia reduces the incidence and severity of coughing without serious adverse events and may provide haemodynamic stability in patients undergoing thyroidectomy. However, awakening may be delayed.

Effect of ketamine as an adjunct to intravenous patient-controlled analgesia, in patients at high risk of postoperative nausea and vomiting undergoing lumbar spinal surgery

BACKGROUND We evaluated the effect of ketamine as an adjunct to a fentanyl-based i.v. patient-controlled analgesia (IV-PCA) on postoperative nausea and vomiting (PONV) in patients at high risk of PONV undergoing lumbar spinal surgery. METHODS Fifty non-smoking female patients were evenly randomized to either the control or ketamine group. According to randomization, patients received either ketamine 0.3 mg kg(-1) i.v. or normal saline after anaesthetic induction with fentanyl-based IV-PCA either with or without ketamine mixture (3 mg kg(-1) in 180 ml). The incidence and severity of PONV, volume of IV-PCA consumed, and pain intensity were assessed in the postanaesthesia care unit, and at postoperative 6, 12, 24, 36, and 48 h. RESULTS The overall incidence of PONV during the first 48 h after surgery was similar between the two groups (68 vs 56%, ketamine and control group, P=0.382). The total dose of fentanyl used during the first 48 h after operation was lower in the ketamine group than in the control group [mean (SD), 773 (202) μg vs 957 (308) μg, P=0.035]. The intensity of nausea (11-point verbal numerical rating scale) was higher in the ketamine group during the first 6 h after operation [median (interquartile range), 6 (3-7) vs 2 (1.5-3.5), P=0.039], postoperative 12-24 h [5 (4-7) vs 2 (1-3), P=0.014], and postoperative 36-48 h [5 (4-7) vs 2 (1-3), P=0.036]. Pain intensities were similar between the groups. CONCLUSIONS Ketamine did not reduce the incidence of PONV and exerted a negative influence on the severity of nausea. It was, however, able to reduce postoperative fentanyl consumption in patients at high-risk of PONV.

Dexmedetomidine added to an opioid-based analgesic regimen for the prevention of postoperative nausea and vomiting in highly susceptible patients: A randomised controlled trial.

BACKGROUND Dexmedetomidine, an &agr;2 adrenergic receptor agonist, has analgesic, sedative and sympatholytic properties, with a lack of respiratory depression. It is licensed only for intensive care sedation. OBJECTIVE The objective of this study is to investigate whether intravenous (i.v.) patient-controlled analgesia (PCA) with dexmedetomidine added to a fentanyl-based drug mixture could reduce postoperative nausea and vomiting (PONV) in highly susceptible patients undergoing lumbar spinal surgery. DESIGN A randomised, double-blinded study. SETTING At a tertiary university hospital between September 2012 and September 2013. PATIENTS One hundred and eight patients undergoing level 1 or 2 posterior lumbar spinal fusion who had at least three risk factors for PONV (female, nonsmoker, use of postoperative opioids) were randomised into two groups. Three patients were excluded from analysis and 105 patients completed the study. METHODS Patients received either dexmedetomidine 0.5 &mgr;g kg−1 i.v. (dexmedetomidine group) or 0.9% normal saline (control group) 30 min before the completion of surgery followed by fentanyl 0.5 &mgr;g kg−1 and 4 mg ondansetron. Postoperatively, the PCA (fentanyl 10 &mgr;g kg−1 with 120 mg ketorolac, with or without dexmedetomidine 10 &mgr;g kg−1 made up to a total volume of 100 ml) was programmed to deliver 1 ml bolus (lockout 15 min) with a continuous background infusion of 2 ml h−1. The PCA was used for the first 48 h postoperatively. MAIN OUTCOME MEASURES The incidence and severity of PONV, cumulative dose of PCA fentanyl consumed and pain scores were assessed for 48 h. RESULTS The dexmedetomidine group experienced less nausea during the time interval 1 to 3 h postoperatively compared with the control group [odds ratio (OR) 0.32; 95% confidence interval (CI) 0.13 to 0.77; P = 0.019]. The intensity of nausea between the groups during the first 48 h was comparable, but the dexmedetomidine group had a lower incidence of moderate to severe nausea (OR 0.28; 95% CI 0.12 to 0.67; P < 0.003). Pain scores were not significantly different between the groups, but patients in the dexmedetomidine group required less fentanyl and less rescue analgesia in the first 12 h. Compared with the control group, patients in the dexmedetomidine group experienced almost twice as many episodes of hypotension and bradycardia, but this failed to reach statistical significance. CONCLUSION Adding dexmedetomidine to a fentanyl-based PCA drug mixture reduces the frequency and severity of acute postoperative nausea in highly susceptible patients. TRIAL REGISTRATION Clinicaltrials.gov identifier: NCT01840254.

Impact of intraoperative hyperglycaemia on renal dysfunction after off-pump coronary artery bypass

OBJECTIVES Acute kidney injury (AKI) is one of the most frequently occurring complications after off-pump coronary artery bypass graft (OPCAB). Hyperglycaemia is a major, potentially modifiable risk factor of adverse outcome after cardiac surgery known to aggravate organ damage. The aim of this study was to address the association between intraoperative glucose concentration and postoperative AKI in patients who underwent OPCAB. METHODS The medical records of 880 consecutive patients were retrospectively reviewed. Patients were divided into three groups according to the time-weighted average of intraoperative glucose concentrations (<110, 110-150 and >150 mg/dl), and the incidence of AKI (increase of serum creatinine to >2.0 mg/dl and 2 × most recent preoperative value or a new requirement for dialysis) was compared. Multivariate logistic regression analysis was performed to identify independent risk factors for postoperative AKI. RESULTS The incidence of AKI was higher in patients with a glucose level >150 mg/dl than in patients with a glucose level = 110-150 mg/dl [8% (20 of 251) vs 3% (14 of 453), P = 0.004]. On multivariate analysis, glucose >150 mg/dl (odds ratio [OR], 2.78; 95% confidence interval [CI], 1.12-6.86, P = 0.027), coefficient of variation of glucose (OR, 1.04; 95% CI, 1.01-1.07, P = 0.027) and preoperative serum creatinine >1.4 mg/dl (OR, 8.81; 95% CI, 3.90-19.9, P < 0.001) were identified as independent risk factors for postoperative AKI. CONCLUSIONS Intraoperative glucose concentration >150 mg/dl and increased variability of glucose were independently associated with AKI after OPCAB. Tight intraoperative glycaemic control (<110 mg/dl) does not seem to provide additional benefit in terms of AKI.

The uncalibrated pulse contour cardiac output during off-pump coronary bypass surgery: performance in patients with a low cardiac output status and a reduced left ventricular function

Background We compared the continuous cardiac index measured by the FloTrac/Vigileo™ system (FCI) to that measured by a pulmonary artery catheter (CCI) with emphasis on the accuracy of the FCI in patients with a decreased left ventricular ejection fraction (LVEF) and a low cardiac output status during off-pump coronary bypass surgery (OPCAB). We also assessed the influence of several factors affecting the pulse contour, such as the mean arterial pressure (MAP), the systemic vascular resistance index (SVRI) and the use of norepinephrine. Methods Fifty patients who were undergoing OPCAB (30 patients with a LVEF ≥ 40%, 20 patients with a LVEF < 40%) were enrolled. The FCI and CCI were measured and we performed a Bland-Altman analysis. Subgroup analyses were done according to the LVEF (< 40%), the CCI (≤ 2.4 L/min/m), the MAP (60-80 mmHg), the SVRI (1,600-2,600 dyne/s/cm5/m2) and the use of norepinephrine. Results The FCI was reliable at all the time points of measurement with an overall bias and limit of agreement of -0.07 and 0.67 L/min/m2, respectively, resulting in a percentage error of 26.9%. The percentage errors in the patients with a decreased LVEF and in a low cardiac output status were 28.2% and 22.3%, respectively. However, the percentage error in the 91 data pairs outside the normal range of the SVRI was 40.2%. Conclusions The cardiac output measured by the FloTrac/Vigileo™ system was reliable even in patients with a decreased LVEF and in a low cardiac output status during OPCAB. Acceptable agreement was also noted during the period of heart displacement and grafting of the obtuse marginalis branch.

Double-blinded, randomized controlled trial of N-acetylcysteine for prevention of acute kidney injury in high risk patients undergoing off-pump coronary artery bypass

The aim of this study was to investigate the influence of perioperative N‐acetylcysteine (NAC) administration, a known antioxidant, on the incidence of acute kidney injury (AKI) after off‐pump coronary bypass surgery (OPCAB) in patients with known risk factors of AKI.

Effect of a single bolus of methylene blue prophylaxis on vasopressor and transfusion requirement in infective endocarditis patients undergoing cardiac surgery

Background The accentuated nitric oxide (NO) release that is induced by the systemic inflammatory response associated with infective endocarditis (IE) and cardiopulmonary bypass (CPB) may result in catecholamine refractory hypotension (vasoplegia) and increased transfusion requirement due to platelet inhibition. Methylene blue (MB) is an inhibitory drug of inducible NO. We aimed to evaluate the effect of prophylactic MB administration before CPB on vasopressor and transfusion requirements in patients with IE undergoing valvular heart surgery (VHS). Methods Forty-two adult patients were randomly assigned to receive 2 mg/kg of MB (MB group, n = 21) or saline (control group, n = 21) for 20 min before the initiation of CPB. The primary end points were comparisons of vasopressor requirements serially assessed after weaning from CPB and hemodynamic parameters serially recorded before and after CPB. The secondary endpoint was the comparison of transfusion requirements. Results Two patients in the control group received MB after weaning from CPB due to norepinephrine and vasopressin refractory vasoplegia and were thus excluded. There were no significant differences in vasopressor requirements and hemodynamic parameters between the two groups. The mean number of units of packed erythrocytes transfused per transfused patient was significantly less in the MB group. The numbers of patients transfused with fresh frozen plasma and platelet concentrates were less in the MB group. Conclusions In IE patients undergoing VHS, prophylactic MB administration before CPB did not confer significant benefits in terms of vasopressor requirements and hemodynamic parameters, but it was associated with a significant reduction in transfusion requirement.