Yong Seon Choi

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.

Risk Assessment of Postoperative Nausea and Vomiting in the Intravenous Patient-Controlled Analgesia Environment: Predictive Values of the Apfel's Simplified Risk Score for Identification of High-Risk Patients

Purpose Opioid-based intravenous patient-controlled analgesia (IV PCA) is popular method of postoperative pain control, but many patients suffer from IV PCA-related postoperative nausea and vomiting (PONV). In this retrospective observational study, we have determined independent predictors of IV PCA-related PONV and predictive values of the Apfels simplified risk score in pursuance of identifying high-risk patients. Materials and Methods We analyzed 7000 patients who received IV PCA with background infusion after elective surgery. Patients who maintained IV PCA for a postoperative period of 48 hr (completion group, n=6128) were compared with those who have discontinued IV PCA within 48 hr of surgery due to intractable PONV (cessation group, n=872). Patients, anesthetics, and surgical factors known for predicting PONV were evaluated by logistic regression analysis to identify independent predictors of IV PCA related intractable PONV. Results In a stepwise multivariate analysis, weight, background infusion dose of fentanyl, addition of ketolorac to PCA, duration of anesthesia, general anesthesia, head and neck surgery, and Apfels simplified risk score were revealed as independent risk factors for intractable PONV followed by the cessation of IV PCA. In addition, Apfels simplified risk score, which demonstrated the highest odds ratio among the predictors, was strongly correlated with the cessation rate of IV PCA. Conclusion Multimodal prophylactic antiemetic strategies and dose reduction of opioids may be considered as strategies for the prevention of PONV with the use of IV PCA, especially in patients with high Apfels simplified risk scores.

Effects of ulinastatin treatment on myocardial and renal injury in patients undergoing aortic valve replacement with cardiopulmonary bypass

Background We determined the protective effects of a high dose of ulinastatin on myocardial and renal function in patients undergoing aortic valve replacement with cardiopulmonary bypass (CPB). Methods Sixty patients were assigned randomly to either the ulinastatin group (n = 30) or the control group (n = 30). In the ulinastatin group, ulinastatin (300,000 U) was given after the induction of anesthesia, ulinastatin (400,000 U) was added to the CPB pump prime, and then ulinastatin (300,000 U) was administered after weaning from CPB. In the control group, the same volume of saline was administered at the same time points. Creatine kinase-MB levels were assessed 1 day before surgery, and on the first and second postoperative day (POD 1 and 2). Serum creatinine and cystatin C levels were assessed 1 day before surgery, upon intensive care unit arrival, and on POD 1 and 2. The level of plasma neutrophil gelatinase-associated lipocalin was assessed before induction of anesthesia, upon ICU arrival, and on POD 1. Results No significant differences were observed in serum levels of creatine kinase-MB and biomarkers of renal injury between the two groups at any point during the study period. Conclusions Ulinastatin showed no cardiac or renal protective effects after CPB in patients undergoing aortic valve replacement.

Efficacy of dexamethasone added to ramosetron for preventing postoperative nausea and vomiting in highly susceptible patients following spine surgery

Background Opioid-based patient controlled analgesia (PCA) provides adequate pain control following spinal surgeries at the expense of increased risk of postoperative nausea and vomiting (PONV). We evaluated the efficacy of dexamethasone added to ramosetron, which is a newly developed five-hydroxytryptamine receptor 3 antagonist with a higher receptor affinity and longer action duration compared to its congeners, on preventing PONV in highly susceptible patients receiving opioid-based IV PCA after spinal surgery. Methods One hundred nonsmoking female patients undergoing spinal surgery were randomly allocated to either a ramosetron group (group R) or a ramosetron plus dexamethasone group (group RD)., Normal saline (1 ml) or 5 mg of dexamethasone was injected before anesthetic induction, while at the end of the surgery, ramosetron (0.3 mg) was administered to all patients and fentanyl-based IV PCA was continued for 48 hrs. The incidence and severity of PONV, pain score and the amount of rescue antiemetics were assessed for 48 hours after surgery. Results The number of patients with moderate to severe nausea (20 vs. 10, P = 0.029), and overall incidence of vomiting (13 vs. 5, P = 0.037) were significantly lower in the group RD than in the group R, respectively. Rescue antiemetic was used less in the RD group without significance. Conclusions Combination of ramosetron and dexamethasone significantly reduced the incidence of moderate to severe nausea and vomiting compared to ramosetron alone in highly susceptible patients receiving opioid-based IV PCA after surgery.

Efficacy comparison of ramosetron with ondansetron on preventing nausea and vomiting in high-risk patients following spine surgery with a single bolus of dexamethasone as an adjunct

Background Despite the development of a new class of antiemetics, postoperative nausea and vomiting (PONV) still remains a frequent and distressing complication. We compared the prophylactic antiemetic effect of administering dexamethasone 5 mg as an adjunct to ramosetron and ondansetron in patients at high-risk for PONV following lumbar spinal surgery. Methods In this randomized, double-blind study, 120 female non-smoking patients with intravenous patient-controlled analgesia (PCA) received ramosetron 0.3 mg plus dexamethasone 5 mg (group R + D) or ondansetron 4 mg plus dexamethasone 5 mg (group O + D) intravenously. Fentanyl-based PCA was administered for 48 hr postoperatively; ramosetron 0.3 mg or ondansetron 12 mg was added to the PCA regimen according to the allocated group. The incidence of PONV and rescue antiemetic were assessed for 48 hr postoperatively at 0-6, 6-24, and 24-48 hr. Results The overall incidence of PONV did not differ between the groups (50% vs. 60%, in groups R + D and O + D, respectively). The overall incidence of nausea was similar between groups (47% vs. 60%, in groups R + D and O + D, respectively). The overall frequency of vomiting was also similar between groups (8% vs. 12%, in groups R + D and O + D, respectively). The severity of nausea and the overall use of rescue antiemetic were not different between groups. Conclusions The antiemetic efficacy of ramosetron plus dexamethasone was similar to that of ondansetron plus dexamethasone on preventing PONV in high-risk patients undergoing lumbar spinal surgery.

Carbon dioxide embolism induced right coronary artery ischaemia during off-pump obtuse marginalis artery grafting

Although use of carbon dioxide (CO2) blower has been regarded safe during off-pump coronary bypass surgery (OPCAB), we experienced a case of right coronary artery ischaemia induced by retrograde CO2 embolism originating from the opened obtuse marginalis artery during OPCAB. The spray pressure can exceed the diastolic pressure, especially during grafting at the lateral or posterior wall when haemodynamic compromise due to mechanical heart displacement is most severe. In this situation, CO2 blowing at an incompletely slinged coronary arteriotomy site can result in retrograde migration of CO2 into the ascending aorta causing coronary embolism of the right coronary artery. When signs of ischaemia on the right coronary artery are encountered during grafting of other coronary artery, although CO2 blower has been used, gas embolism should also be considered as the cause and identified at the mid-oesophageal aortic valve long-axis view. When confirmed, the use of gas blower should immediately be discontinued and coronary perfusion pressure increased while allowing time for the CO2 to be absorbed. In case of massive embolism, needle aspiration of the gas should also be considered.