Jae Kwang Shim

Effect of remote ischemic preconditioning on renal dysfunction after complex valvular heart surgery: A randomized controlled trial

OBJECTIVE Acute kidney injury after cardiac surgery with cardiopulmonary bypass is closely related to systemic inflammatory reactions and oxidative stresses. Remote ischemic preconditioning is a systemic protective strategy whereby brief limb ischemia confers systemic protection against prolonged ischemia and inflammatory reactions in distant organs. This study investigated whether remote ischemic preconditioning provides systemic protective effect on kidneys that are not directly exposed to ischemia-reperfusion injury during complex valvular heart surgery. METHODS Seventy-six adult patients undergoing complex valvular heart surgery were randomly assigned to either remote ischemic preconditioning group (n = 38) or control group (n = 38). Remote ischemic preconditioning consisted of 3 10-minute cycles of lower limb ischemia and reperfusion with an automated cuff inflator. Primary end points were comparisons of biomarkers of renal injury including serum creatinine, cystatin C and neutrophil gelatinase-associated lipocalin, and incidence of acute kidney injury. Secondary end points were comparisons of myocardial enzyme release and pulmonary parameters. RESULTS There were no significant differences in serum levels of biomarkers of renal injury between groups throughout the study period. The incidence of acute kidney injury did not differ between groups. Creatine kinase isoenzyme MB at 24 hours after surgery was lower, and intensive care unit stay was shorter in the remote ischemic preconditioning group than in the control group. CONCLUSIONS In patients undergoing complex valvular heart surgery, remote ischemic preconditioning did not reduce degree of renal injury or incidence of acute kidney injury whereas it did reduce myocardial injury and intensive care unit stay.

Effective dose of peri-operative oral pregabalin as an adjunct to multimodal analgesic regimen in lumbar spinal fusion surgery.

Study Design. A prospective, randomized, controlled, and double-blind trial. Objective. To evaluate the effects of 2 different doses of perioperative pregabalin administration, twice on the day of surgery, on acute postoperative pain after spinal surgery. Summary of Background Data. Besides its well-established role on neuropathic pain, pregabalin seems to be a promising adjunct to multimodal analgesic regimen following surgery. No comprehensive data exist regarding the optimal dosage of pregabalin on reducing postoperative pain and opioid consumption in spinal surgery. Methods. Patients were randomly assigned to 1 of 3 groups. The placebo group (n = 28) received placebo capsules 1 hour before the anesthetic induction and 12 hours after surgery. The pregabalin groups received pregabalin 75 mg (P75 group, n = 28) or 150 mg (P150 group, n = 28), respectively at the same points. Assessed variables were total amount of administered fentanyl-based intravenous patient-controlled analgesia, pain intensity, and the frequency of rescue analgesic administered during the first 48 hours after surgery, subdivided into the following 4 periods: on arrival of patient to the postanesthesia care unit, 1 to 6 hours, 6 to 24 hours, and 24 to 48 hours. Results. The amount of patient-controlled analgesia volume infused until 24 hours (P = 0.025) and 48 hours (P = 0.028) after surgery was significantly less in the P150 group compared with the control group. The frequency of additional anodynes administered until 6 hours (P = 0.049) and 24 hours (P = 0.045) after surgery was significantly less in the P150 group compared with the control group. Conclusion. Perioperative administration of pregabalin 150 mg before and 12 hours after surgery, but not 75 mg, significantly reduced opioid consumption and the use of additional pain rescue for 48 hours after surgery without significant side effects in patients undergoing spinal fusion surgery.

Effect of Ramosetron on Patient-controlled Analgesia Related Nausea and Vomiting After Spine Surgery in Highly Susceptible Patients: Comparison With Ondansetron

Study Design. A prospective, randomized, double-blind clinical trial. Objective. To compare the effect of ramosetron with that of ondansetron on opioid-based IV patient-controlled analgesia (PCA) related postoperative nausea and vomiting (PONV) in highly susceptible patients after lumbar spine surgery. Summary of Background Data. Optimal postoperative pain management is important to facilitate early mobilization after lumbar spine surgery. Opioid analgesia is associated with a high incidence of PONV. Among the currently available 5-hydroxytryptamine receptor 3 antagonists (5-HT3), ondansetron is being most widely used with unsatisfactory results regarding opioid-based IV PCA related PONV. Ramosetron is a newly developed 5-HT3 antagonist with higher receptor affinity and longer duration of action having theoretical advantage over ondansetron in this setting. However, data to support this view are lacking. Methods. All 94 female nonsmoker patients (aged 18–65 years) were randomly allocated into either ondansetron group (group O, n = 47) or ramosetron group (group R, n = 47). Fentanyl-based IV PCA was administered for 48 hours after surgery. Overall incidence and severity of nausea and incidence of vomiting were assessed for 48 hours after surgery. Secondary measures included: pain intensity and total amount of administered rescue analgesic. Results. Patients’ characteristics were similar between the groups. Overall incidence of nausea was similar between the groups; however, moderate to severe degree of nausea was significantly more in the group O (34%) than in the group R (13%) 6 to 24 hours after surgery. Overall incidence of vomiting and use of rescue antiemetic 6 to 24 hours after surgery was significantly lower in the group R (30% vs. 11% and 28% vs. 11%, respectively). Pain scores at 24 to 48 hours after surgery were significantly lower in the group R (31 ± 25 vs. 13 ± 15). Conclusion. Ramosetron was superior to ondansetron in terms of preventing vomiting and reducing the severity of nausea related to fentanyl-based IV PCA, with less adverse events, in patients with high susceptibility, undergoing lumbar spine surgery.

Risk factors of atrial fibrillation following off-pump coronary artery bypass graft surgery: predictive value of C-reactive protein and transfusion requirement.

OBJECTIVES Considering the role of inflammatory reaction on the pathogenesis of atrial fibrillation (AF), the aim of this study is to investigate perioperative risk factors of AF, as well as to validate the predictive value of high-sensitive C-reactive protein (hsCRP), and transfusion requirement following off-pump coronary bypass surgery (OPCAB) in a prospective and observational trial. METHODS In this cohort, 315 consecutive patients with normal sinus rhythm (NSR) undergoing elective isolated OPCAB are prospectively studied. The patients were classified as either NSR or AF group according to their postoperative rhythm, which was continuously monitored for the first 6 postoperative days. RESULTS AF developed in 66 patients (19%). Univariate analysis demonstrated old age, pre-existing chronic renal failure, low left ventricle ejection fraction (LVEF <30%), highest hsCRP before the onset of AF, vasopressor and inotropic therapy, packed red blood cells (pRBCs) transfusion and amount of chest tube drainage as predictors of postoperative AF. In a stepwise multivariate analysis of these risk factors, low LVEF (odds ratio: 2.88; 95% confidence interval: 1.07-7.75; p=0.037), highest hsCRP before the onset of AF (odds ratio: 1.06; 95% confidence interval: 1.01-1.11; p=0.018), vasopressor therapy (odds ratio: 1.93; 95% confidence interval: 1.04-3.57; p=0.038) and pRBC transfusion (odds ratio: 5.32; 95% confidence interval: 2.80-10.11; p<0.001) remained as independent predictors of postoperative AF. CONCLUSIONS Prophylactic strategies aimed at AF reduction may also be considered especially in patients with increased transfusion requirement, which showed highest predictive value for postoperative AF.

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.

Efficacy of palonosetron versus ramosetron on preventing opioid-based analgesia-related nausea and vomiting after lumbar spinal surgery: A prospective, randomized, and double-blind trial

Study Design. A prospective, randomized, and double-blind study. Objective. To compare the efficacy of ramosetron and palonosetron on preventing postoperative nausea and vomiting (PONV) associated with opioid-based intravenous patient-controlled analgesia (IV-PCAopioid) after lumbar spinal surgery. Summary of Background Data. IV-PCAopioid, an effective method to control pain after lumbar spinal surgery, accompanies PONV. Ramosetron and palonosetron are novel 5-hydroxytryptamine 3 antagonists known to have longer action duration and higher receptor affinity than their congeners, whereas their relative efficacy has not been validated yet. Methods. One hundred ninety-six patients were randomly and evenly allocated to receive either 0.3 mg of ramosetron or 0.075 mg of palonosetron 10 minutes before the end of operation. Ramosetron or palonosetron were also added to the IV-PCAopioid, which was continuously infused for 48 hours postoperatively. The incidence and intensity of PONV were serially assessed for 72 hours postoperatively. Intensity of pain, volume of IV-PCAopioid consumption, use of rescue analgesics and antiemetics, and adverse events were also assessed. Results. The overall incidence of PONV was lower in the ramosetron group than the palonosetron group (50% vs. 67%, P = 0.014) without any intergroup difference in the incidence of vomiting. Nausea intensity scores were also lower until 6 (P = 0.041) and 24 hour (P = 0.026) postoperatively in the ramosetron group than the palonosetron group. Pain intensity scores were significantly lower in the ramosetron group than the palonosetron group for 72 hours postoperatively. Conclusion. Ramosetron was superior to palonosetron in term of reducing the incidence and severity of nausea associated with IV-PCAopioid after lumbar spinal surgery. This favorable influence of ramosetron on PONV was translated to significant postoperative pain reduction compared with palonosetron. Level of Evidence: 1

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.

Improved sedation with dexmedetomidine–remifentanil compared with midazolam–remifentanil during catheter ablation of atrial fibrillation: a randomized, controlled trial

AIMS Anaesthesia is required for catheter ablation of atrial fibrillation (A-fib) to achieve patient comfort and immobilization to avoid map shifts. This study compared the analgesic and sedative efficacies of dexmedetomidine-remifentanil with those of midazolam-remifentanil for catheter ablation of A-fib. METHODS AND RESULTS Ninety patients were randomized to receive either intermittent midazolam boluses (1-2 mg) with 3.6-7.2 µg/kg/h of remifentanil (MR group) or dexmedetomidine 0.2-0.7 µg/kg/h after a loading dose of 1 µg/kg with 1.2-2.4 µg/kg/h of remifentanil (DR group). The sedation level assessed by the Ramsay sedation and bispectral index scores, haemodynamic variables, pain score (10-point numerical scale), and satisfaction levels of the patients and cardiologists (5-point numerical scale) were recorded. The Ramsay sedation score was significantly higher, and the bispectral index score was lower in the DR group (P< 0.001) compared with the MR group starting 10 min after drug administration. The incidence of desaturation (SpO2 < 90%) was significantly greater in the MR group compared with the DR group (15 vs. 1, P < 0.001). The pain score was significantly lower (1.72 ± 1.65 vs. 0.95 ± 1.10, P = 0.021), and the satisfaction levels of interventionists were significantly higher (2.50 ± 0.71 vs. 3.00 ± 0.63, P = 0.001) in the DR group compared with the MR group. CONCLUSION The combination of dexmedetomidine and remifentanil provided deeper sedation, less respiratory depression, better analgesia, and higher satisfaction for the interventionist during catheter ablation of A-fib compared with midazolam plus remifentanil, even at a lower dose of remifentanil.

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.