Tae Kyong Kim

Influence of high-dose intraoperative remifentanil with intravenous ibuprofen on postoperative morphine consumption in patients undergoing pancreaticoduodenectomy: a randomized trial.

STUDY OBJECTIVE High-dose remifentanil during surgery paradoxically increases postoperative pain intensity and morphine consumption. Cyclooxygenase inhibitors decrease prostaglandin synthesis, thereby antagonizing N-methyl-d-aspartate receptor activation, and may reduce hyperalgesia. This study was performed to evaluate whether postoperative morphine consumption increased following intraoperative continuous remifentanil infusion and whether this could be prevented by intravenous ibuprofen pretreatment. DESIGN A randomized controlled study. SETTING Single university hospital, study period from September 2014 to March 2015. PATIENTS One hundred and twenty patients undergoing pancreaticoduodenectomy. INTERVENTIONS After induction of anesthesia, patients received remifentanil target-controlled infusion (effect site concentration of 4 ng/mL or 1 ng/mL) with or without intravenous ibuprofen (800 mg). MEASUREMENTS Postoperative cumulative total morphine consumption and pain intensity were assessed. MAIN RESULTS Intraoperative remifentanil use in patients receiving high-dose remifentanil was more than 3-fold higher than that in patients receiving low-dose remifentanil (2666.8 ± 858.4 vs 872.0 ± 233.3 μg, respectively; P< .001). However, cumulative total morphine consumption at postoperative 1, 3, 6, 12, 24, and 48 hours did not differ among the groups. There were no differences among the groups in the self-administered analgesic dose by the patients using a controlled analgesia device, number of self-administration attempts, numerical rating scale for pain, or analgesic side effects. CONCLUSIONS We found no influence on postoperative pain after high-dose remifentanil in patients undergoing pancreaticoduodenectomy. Addition of intravenous ibuprofen did not reduce postoperative morphine consumption or pain intensity.

Microvascular reactivity and clinical outcomes in cardiac surgery

IntroductionMicrovascular reactivity is decreased in patients with septic shock; this is associated with worse clinical outcomes. The objectives of the present study were to investigate microvascular reactivity in cardiac surgery patients and to assess any association with clinical outcomes.MethodsWe retrospectively analyzed a prospectively collected registry. In total, 254 consecutive adult patients undergoing cardiac and thoracic aortic surgeries from January 2013 through May 2014 were analyzed. We performed a vascular occlusion test (VOT) by using near-infrared spectroscopy to measure microvascular reactivity. VOT was performed three times per patient: prior to the induction of anesthesia, at the end of surgery, and on postoperative day 1. The primary endpoint was a composite of major adverse complications, including death, myocardial infarction, acute kidney injury, acute respiratory distress syndrome, and persistent cardiogenic shock.ResultsVOT recovery slope decreased during the surgery. VOT recovery slope on postoperative day 1 was significantly lower in patients with composite complications than those without (3.1 ± 1.6 versus 4.0 ± 1.5 %/s, P = 0.001), although conventional hemodynamic values, such as cardiac output and blood pressure, did not differ between the groups. On multivariable regression and linear analyses, low VOT recovery slope on postoperative day 1 was associated with increases of composite complications (odds ratio 0.742; 95 % confidence interval (CI) 0.584 to 0.943; P = 0.015) and hospital length of stay (regression coefficient (B) −1.276; 95 % CI −2.440 to −0.112; P = 0.032).ConclusionMicrovascular reactivity largely recovered on postoperative day 1 in the patients without composite complications, but this restoration was attenuated in patients with composite complications.Trial registrationClinicalTrials.gov NCT01713192. Registered 22 October 2012.

Effects of delayed remote ischemic preconditioning on peri-operative myocardial injury in patients undergoing cardiac surgery — A randomized controlled trial

BACKGROUND Remote ischemic preconditioning (RIPC) has two time windows for organ protection: acute and delayed. Previous studies have mainly focused on the acute time window to evaluate organ protection by RIPC. We evaluated myocardial protection by delayed RIPC in adult patients undergoing cardiac surgery. METHODS A total of 160 adult patients undergoing cardiac surgery with cardiopulmonary bypass were randomized to receive either delayed RIPC (four cycles of 5min of ischemia followed by 5min of reperfusion by inflation to 200mmHg and deflation of a blood pressure cuff on the upper arm) or the control treatment 24-48h before surgery. The primary endpoint was post-operative troponin I levels serially measured for 72h. Secondary endpoints included post-operative serum creatinine levels, acute kidney injury, and composite complications. RESULTS There were no significant differences in post-operative troponin I values. The incidence of acute kidney injury, defined by the Acute Kidney Injury Network staging system, was lower in the delayed RIPC group compared to the control group (30.0% vs. 47.5%; relative risk, 0.768; 95% confidence interval, 0.599-0.985; p=0.023). Moreover, the occurrence of composite complications was lower in the delayed RIPC group compared with the control group (65.0% vs. 81.3%; relative risk, 0.536; 95% confidence interval, 0.311-0.924; p=0.020). CONCLUSIONS While RIPC did not provide cardioprotective effects in patients undergoing cardiac surgery, it appeared to reduce acute kidney injury, as well as the rate of composite complications.

Long-term clinical outcomes of Remote Ischemic Preconditioning and Postconditioning Outcome (RISPO) trial in patients undergoing cardiac surgery

BACKGROUND Remote ischemic conditioning has been shown to confer myocardial protection. However, there is still no sufficient data on its long-term clinical outcomes. We analyzed the long-term results of the Remote Ischemic Preconditioning and Postconditioning Outcome (RISPO) trial in cardiac surgery patients. METHODS In the RISPO trial, 1280 patients were randomized to receive remote ischemic preconditioning (RIPC) with postconditioning (RIPostC, upper arm ischemia by four cycles of 5-min inflation followed by 5-min deflation of a pneumatic cuff, N=644) or sham (N=636) during cardiac surgery. Patient follow-up data were collected by review of medical records, telephone interviews, and from the National Statistical Office. The primary endpoint was major adverse cardiac and cerebrovascular events (MACCE; a composite of all-cause mortality, myocardial infarction (MI), stroke, and revascularization), and the secondary endpoints were the individual components of the primary endpoint. RESULTS At completion of follow-up (mean 44months), there was no difference in MACCE between the groups (90 [14.0%] versus 101 [15.9%] in the RIPC with RIPostC versus control groups; hazard ratio [HR], 0.893; 95% confidence interval [CI], 0.672-1.187; P=0.435). However, MI was reduced to half in the RIPC with RIPostC group (10 [1.6%] versus 23 [3.6%]; HR, 0.468; 95% CI, 0.222-0.984; P=0.045). CONCLUSIONS Remote ischemic preconditioning with RIPostC did not improve long-term MACCE after cardiac surgery. However, MI was reduced in the RIPC with RIPostC group compared with the control group during the follow-up period. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov identifier, NCT00997217.

Pulmonary Protective Effects of Remote Ischaemic Preconditioning with Postconditioning in Patients Undergoing Cardiac Surgery Involving Cardiopulmonary Bypass: A Substudy of the Remote Ischaemic Preconditioning with Postconditioning Outcome trial.

BACKGROUND The RISPO (Remote Ischemic Preconditioning with Postconditioning Outcome) trial evaluated whether remote ischaemic preconditioning (RIPC) combined with remote ischaemic postconditioning (RIPostC) improves the clinical outcomes of patients undergoing cardiac surgery. This substudy of the RISPO trial aimed to evaluate the effect of RIPC with RIPostC on pulmonary function in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). METHODS Sixty-five patients were enrolled (32: control and 33: RIPC-RIPostC). In the RIPC-RIPostC group, four cycles of 5min ischaemia and 5min reperfusion were administered before and after CPB to the upper limb. Peri-operative PaO2/FIO2 ratio, intra-operative pulmonary shunt, and dynamic and static lung compliance were determined. RESULTS The mean PaO2/ FIO2 was significantly higher in the RIPC-RIPostC group at 24h after surgery [290 (96) vs. 387 (137), p=0.001]. The incidence of mechanical ventilation for longer than 48h was significantly higher in the control group (23% vs. 3%, p<0.05). However, there were no significant differences in other pulmonary profiles, post-operative mechanical ventilation time, and duration of intensive care unit stay. CONCLUSIONS In our study, RIPC-RIPostC improved the post-operative 24h PaO2/FIO2 ratio. Remote ischaemic preconditioning-Remote ischaemic postconditioning has limited and delayed pulmonary protective effects in cardiac surgery patients with CPB.

Comparison of Needle Insertion and Guidewire Placement Techniques During Internal Jugular Vein Catheterization: The Thin-Wall Introducer Needle Technique Versus the Cannula-Over-Needle Technique.

Objectives:For needle insertion and guidewire placement during central venous catheterization, a thin-wall introducer needle technique and a cannula-over-needle technique have been used. This study compared these two techniques regarding the success rates and complications during internal jugular vein catheterization. Design:Prospective, randomized, controlled study. Setting:A university-affiliated hospital. Patients:Two hundred sixty-six patients scheduled for thoracic surgery, gynecologic surgery, or major abdominal surgery, who required central venous catheterization. Interventions:Patients were randomly assigned to either the thin-wall introducer needle group (n = 134) or the cannula-over-needle group (n = 132). Central venous catheterization was performed on the right internal jugular vein under assistance with real-time ultrasonography. Needle insertion and guidewire placement were performed using a thin-wall introducer needle technique in the thin-wall introducer needle group and a cannula-over-needle technique in the cannula-over-needle group. Measurements and Main Results:The guidewire placement on the first skin puncture was regarded as a successful guidewire insertion on the first attempt. The number of puncture attempts for internal jugular vein catheterization was recorded. Internal jugular vein was assessed by ultrasonography to identify complications. The rate of successful guidewire insertion on the first attempt was higher in the thin-wall introducer needle group compared with the cannula-over-needle group (87.3% vs 77.3%; p = 0.037). There were fewer puncture attempts in the thin-wall introducer needle group than in the cannula-over-needle group (1.1 ± 0.4 vs 1.3 ± 0.6; p = 0.026). There was no significant difference in complications of internal jugular vein catheterization between the two groups. Conclusions:The thin-wall introducer needle technique showed a superior success rate for first attempt of needle and guidewire insertion and required fewer puncture attempts during internal jugular vein catheterization.

Efficacy of intrathecal morphine for postoperative pain management following open nephrectomy

Objective To evaluate the efficacy and safety of intrathecal morphine (ITM) for postoperative pain control in patients with renal cell carcinoma undergoing open nephrectomy. Methods Forty-five patients scheduled for open nephrectomy were randomised to receive 300 µg ITM and intravenous patient-controlled analgesia (IV-PCA) (n = 22) or IV-PCA alone (n = 23) for postoperative analgesia. The numeric pain score (NPS), postoperative IV-PCA requirements and opioid-related complications including nausea, vomiting, dizziness, headache, and pruritus were compared between groups. Results NPS was significantly lower in the ITM group up to 24 h postoperatively. Upon coughing, NPS at 24 h postoperatively was 50 (interquartile range (IQR) 30–60) in the ITM group and 60 (45–70) in the IV-PCA group. Cumulative morphine consumption at 72 h postoperatively was significantly lower in the ITM group compared with the IV-PCA group (20 (9–33) mg vs. 31 (21–49) mg, respectively). Opioid-related complications were similar in both groups with the exception of pruritus (ITM, 77% vs. IV-PCA, 26%). Conclusions ITM was associated with greater analgesia without serious complications in patients undergoing open nephrectomy.

Increased tracheal cuff pressure during insertion of a transoesophageal echocardiography probe: A prospective, observational study.

BACKGROUND Excessive tracheal cuff pressure reduces tracheal mucosal blood flow and increases tracheal morbidity. Inserting a transoesophageal echocardiography (TOE) probe has been shown to increase tracheal cuff pressure. OBJECTIVE To evaluate the effect of inserting a TOE probe on tracheal cuff pressure and compare the effect in patients who received a single-lumen endotracheal tube (SLT) with those who received a double-lumen endotracheal tube (DLT). DESIGN A prospective, observational study. SETTING Single-centre trial, study period from October 2013 to January 2014. PATIENTS Forty-four adult patients scheduled for elective cardiothoracic surgery requiring intraoperative TOE monitoring. INTERVENTIONS After tracheal intubation with a SLT (n = 22) or DLT (n = 22), the tracheal cuff was inflated to 18 mmHg (25 cmH2O) with air. Tracheal cuff pressure was monitored continuously for 5 min after inserting the TOE probe. MAIN OUTCOME MEASURES The primary endpoint was steady-state tracheal cuff pressure after insertion of the TOE probe. RESULTS Median (interquartile range, IQR) tracheal cuff pressure stabilised at 3 (2 to 3) min in the SLT group and at 2 (1 to 3) min in the DLT group. Steady-state cuff pressure was significantly higher in the DLT group than that in the SLT group [36.7 (31.3 to 44.1) vs. 31.3 (29.6 to 35.7) cmH2O; (P = 0.03)]. Steady-state cuff pressure more than 40 cmH2O was observed in two patients (18.2%) in the SLT group and nine patients (40.9%) in the DLT group (P = 0.02). CONCLUSION Insertion of a TOE probe increased tracheal cuff pressure in both the SLT and DLT groups. The increase in cuff pressure was greater in patients who received a DLT. Frequent measurement and adjustment of cuff pressure should be emphasised particularly when TOE is used in patients receiving a DLT. TRIAL REGISTRATION Clinicaltrials.gov identifier: NCT02034643.

Effect-site concentration of remifentanil required to blunt haemodynamic responses during tracheal intubation: A randomized comparison between single- and double-lumen tubes:

Objective To investigate the effect-site concentration of remifentanil required to blunt haemodynamic responses during tracheal intubation with a single-lumen tube (SLT) or a double-lumen tube (DLT). Methods Patients scheduled for thoracic surgery requiring one-lung ventilation were randomly allocated to either the SLT or DLT group. All patients received a target-controlled infusion of propofol and a predetermined concentration of remifentanil. Haemodynamic parameters during intubation were recorded. The effect-site concentration of remifentanil was determined using a delayed up-and-down sequential allocation method. Results A total of 92 patients were enrolled in the study. The effective effect-site concentrations of remifentanil required to blunt haemodynamic responses in 50% of patients (EC50) estimated by isotonic regression with bootstrapping was higher in the DLT than the SLT group (8.5 ng/ml [95% confidence interval (CI) 8.0–9.5 ng/ml] versus 6.5 ng/ml [95% CI 5.6–6.7 ng/ml], respectively). Similarly, the effective effect-site concentrations of remifentanil in 95% of patients in the DLT group was higher than the SLT group (9.9 ng/ml [95% CI 9.8–10.0 ng/ml] versus 7.0 ng/ml [95% CI 6.9–7.0 ng/ml], respectively). Conclusions This study demonstrated that a DLT requires a 30% higher EC50 of remifentanil than does an SLT to blunt haemodynamic responses during tracheal intubation when combined with a target-controlled infusion of propofol. Trial registration Clinicaltrials.gov identifier: NCT01542099.

Endothelial Shear Stress of the Saphenous Vein Composite Graft Based on the Internal Thoracic Artery

BACKGROUND Endothelial shear stress (ESS) has been suggested as a factor affecting atherosclerosis and remodeling of native vessels and bypass conduits. We compared ESS levels of internal thoracic artery (ITA) and saphenous vein (SV) composite grafts intraoperatively and 1 year after coronary artery bypass grafting (CABG). METHODS Intraoperative ESS was calculated by measuring flow volumes and diameters of proximal and distal ITAs and SV conduits in 23 patients who received SV Y-composite grafts based on the in situ left ITA. Early (1.2 ± 0.5 days) and 1-year (12.9 ± 1.1 months) postoperative angiograms were performed in 23 and 15 patients, respectively. An intragraft Doppler-guidewire study for ESS measurement was performed in 6 patients during 1-year angiography. RESULTS Intraoperative diameters of proximal and distal ITAs and SV conduits were 2.0 ± 0.2 mm, 1.8 ± 0.3 mm, and 3.2 ± 0.4 mm, respectively. ESS levels were significantly different between them (41.0 ± 21.0, 28.4 ± 25.2, and 4.3 ± 3.0 dyne/cm2, respectively). Proximal and distal ITA diameters increased significantly on early angiograms and remained unchanged, but SV diameter increased to 3.7 mm (95% confidence interval, 3.5 to 4.0 mm; p < 0.001) on the early angiogram and decreased to 2.9 mm (95% confidence interval, 2.7 to 3.2 mm; p < 0.001) at 1 year. Significant correlations were found between the initial ESS and proportional changes in conduit diameters during postoperative year 1. SV ESS increased in all 6 patients at 1 year, with no significant differences in ESS levels between the 3 conduits (29.9 ± 7.9, 28.8 ± 7.9, and 21.6 ± 16.3 dyne/cm2, respectively). CONCLUSIONS Initial ESS appears to be associated with proportional changes in conduit diameters in the first year after CABG. ESS values of SV composite grafts were similar to left ITA conduits 1 year after CABG.