Jin Sun Cho

A Comparison of High Volume/Low Concentration and Low Volume/High Concentration Ropivacaine in Caudal Analgesia for Pediatric Orchiopexy

BACKGROUND: It is unclear whether the volume or concentration of local anesthetic influences its spread and quality of caudal analgesia when the total drug dose is fixed. METHODS: We performed this study in a prospective, randomized, observer-blind manner. Children aged 1–5 yr received a constant dose of 2.25 mg/kg of ropivacaine prepared as either 1.0 mL/kg of 0.225% (low volume/high concentration [LVHC], n = 37) or 1.5 mL/kg of 0.15% solution (high volume/low concentration [HVLC], n = 36). Both solutions contained radiopaque dye. RESULTS: The median spread levels with ranges in the HVLC group (confirmed by fluoroscopic examination) were significantly higher (T6, T3-11) than in the LVHC group (T11, T8-L2). There were no significant differences in recovery times, postoperative pain scores, or side effects between the two groups. After discharge, fewer children in the HVLC group required rescue oral acetaminophen compared with the LVHC group (50.0% vs 75.7%). First oral acetaminophen time was found to be significantly longer with HVLC patients than LVHC patients (363.0 min vs 554.5 min). CONCLUSIONS: We confirmed (with fluoroscopy) that a caudal block with 1 mL/kg ropivacaine spreads to T11 and to T6 with 1.5 mL/kg. If the total dose is fixed, caudal analgesia with a larger volume of diluted ropivacaine (0.15%) provides better quality and longer duration after discharge than a smaller volume of more concentrated ropivacaine (0.225%) in children undergoing day-case orchiopexy. The spread level of ropivacaine correlated significantly with the first oral acetaminophen time after discharge.

Fentanyl-sparing Effect of Acetaminophen as a Mixture of Fentanyl in Intravenous Parent-/Nurse-controlled Analgesia after Pediatric Ureteroneocystostomy

Background:Although acetaminophen has been used widely and is well tolerated in children, its efficacy and safety have not been clarified when combined with an opioid in intravenous parent-/nurse-controlled postoperative analgesia. Methods:Sixty-three children (aged 6–24 months) who had undergone elective ureteroneocystostomies were enrolled in this prospective, randomized, double-blinded study. After the surgery, an analgesic pump was programmed to deliver fentanyl at a basal infusion rate of 0.25 &mgr;g · kg−1 · h−1 and 0.25 &mgr;g/kg bolus after a loading dose of 0.5 &mgr;g/kg. In the fentanyl–acetaminophen group, acetaminophen was coadministered as a solution mixture at a basal infusion rate of 1.5 mg · kg−1 · h−1 and 1.5 mg/kg bolus after a loading dose of 15 mg/kg, whereas saline was administered to the fentanyl group. Results:Postoperative pain scores were similar between the two groups. The total dose (micrograms per kilogram per day, mean ± SD) of fentanyl at postoperative days 1 (8.3 ± 3.7 vs. 18.1 ± 4.6, P = 0.021) and 2 (7.0 ± 2.4 vs. 16.6, P = 0.042) was significantly less in the fentanyl–acetaminophen group compared with that in the fentanyl group. The incidences of vomiting (16.1 vs. 56.3%, P = 0.011) and sedation (9.7 vs. 46.9%, P = 0.019) were significantly lower in the fentanyl–acetaminophen group than those in the fentanyl group. Conclusions:Acetaminophen has significant fentanyl-sparing effects and reduces side effects when combined with fentanyl in intravenous parent-/nurse-controlled analgesia for postoperative pediatric pain management.

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.

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.

Effect of Intraoperative Dexmedetomidine Infusion on Postoperative Bowel Movements in Patients Undergoing Laparoscopic Gastrectomy: A Prospective, Randomized, Placebo-Controlled Study

AbstractSympathetic hyperactivation is one of the causes of postoperative ileus, which occurs frequently after abdominal surgery and adversely influences the patients prognosis. We aimed to investigate whether dexmedetomidine (DEX) could attenuate postoperative ileus in patients undergoing laparoscopic gastrectomy.Ninety-two patients were randomized to the control (n = 46) or DEX group (n = 46). DEX was administered at a loading dose of 0.5 &mgr;g/kg for 10 minutes, followed by an infusion rate of 0.4 &mgr;g/kg/h from insufflation of the pneumoperitoneum to the end of surgery. The primary goal was to compare postoperative bowel movements by evaluating the time to first flatus. The balance of the autonomic nervous system, duration of postoperative hospital stay, and pain scores were assessed.The time to first flatus was shorter in the DEX group compared with the control group (67.2 ± 16.8 hours vs 79.9 ± 15.9 hours, P < 0.001). The low-frequency/high-frequency power ratio during pneumoperitoneum increased in the control group, compared with baseline values and the DEX group. The length of postoperative hospital stay was shorter in the DEX group compared with the control group (5.4 ± 0.7 days vs 5.8 ± 1.1 days, P = 0.04). Patients in the DEX group had lower pain scores and required fewer analgesics at 1 hour postoperatively.DEX facilitated bowel movements and reduced the length of hospital stay in patients undergoing laparoscopic gastrectomy. This may be attributed to the sympatholytic and opioid-sparing effects of DEX.

Comparative Analysis of Gene Expression in Normal and Degenerative Human Tendon Cells: Effects of Cyclic Strain

Background: Tendinopathy is a clinical problem for which treatment shows mixed results and treatment options are limited. Gene expression signatures early in the mechanotransduction pathway can accurately predict risk and correlate with different clinical outcomes. Studies aimed at elucidating the molecular mechanisms of tendinopathy have focused on small cohorts of genes that show an incomplete picture of the degeneration process. This study compared the effect of cyclic strain on gene expression in tendon cells from normal tendon and chronically painful areas of tendinopathy in 3 patients. Methods: We measured a panel of mechanotransduction genes and cytoskeletal tensional balance with and without cyclic strain, which disrupts connective tissue synthetic-degradative equilibrium. Normal and degenerative tendons were obtained from patients undergoing surgery to treat chronic painful tendinopathy. A cyclic strain model was established to measure cytoskeletal tensional homeostasis. Results: Prior to cyclic strain, the normal tendon cells exhibited varying patterns of elevated expression of 7 genes compared with degenerative tendon cells. In response to cyclic strain, gene expression of COL1A1, ITGA6, CTNNA1, and CLEC3B was up-regulated in normal tendon cells. Cyclic strain had no effect on degenerative tendon cells. Cyclic strain exacerbated the inhibition of protein synthesis in both cell types, especially in the degenerative tendon cells. Conclusion: Alterations in the pattern of gene expression are suggestive of a dynamic equilibrium between synthesis and degradation, whereby cell adhesion molecules are predominantly up-regulated to facilitate cellular reorientation in response to their altered functional environment. Clinical Relevance: These data might have future applications, including the identification of markers for early diagnosis, targets for drug design, and indicators for treatment responsiveness and prognosis.

Effects of Dexmedetomidine on Changes in Heart Rate Variability and Hemodynamics During Tracheal Intubation.

Sympathetic hyperactivation during tracheal intubation prolongs the QT interval and increases the risk of arrhythmias. We investigated if dexmedetomidine pretreatment affected autonomic nervous system balance and QT intervals during intubation. Sixty-six patients were randomized to receive 1.0 &mgr;g/kg fentanyl (group F, n = 22), 0.5 &mgr;g/kg dexmedetomidine (group D0.5, n = 22), or 1.0 &mgr;g/kg dexmedetomidine (group D1.0, n = 22) before induction. Autonomic nervous system balance was assessed by the ratio of low-frequency/high-frequency (LF/HF) power for heart rate variability at baseline (T0), before intubation (T1), and after intubation (T2). QT intervals were corrected by the Bazetts formula (QTc) and compared at baseline, before intubation, and 1, 2, and 3 minutes after intubation. The LF/HF ratio was higher after intubation compared with that at T0 in group F (P < 0.001). There were no significant changes in groups D0.5 and D1.0. The LF/HF ratio was significantly higher in group F compared with those in groups D0.5 and D1.0 after intubation (7.9 vs. 2.1 and 2.5; P < 0.001). The heart rate was increased for 3 minutes after intubation in group F, whereas only for 1 minute after intubation in groups D0.5 and D1.0, compared with that at baseline. More patients in group F had QTc greater than 440 ms compared with that in group D0.5 or D1.0 (8 vs. 1 and 2; P = 0.005) at 1 minute after intubation. In contrast to 1.0 &mgr;g/kg fentanyl, pretreatment with 0.5 or 1.0 &mgr;g/kg dexmedetomidine suppressed sympathetic hyperactivity and attenuated QTc prolongation during intubation.

Incidence and outcome of contrast-associated acute kidney injury assessed with Risk, Injury, Failure, Loss, and End-stage kidney disease (RIFLE) criteria in critically ill patients of medical and surgical intensive care units: a retrospective study

BackgroundContrast medium used for radiologic tests can decrease renal function. However there have been few studies on contrast-associated acute kidney injury in intensive care unit (ICU) patients. The objective of this study was to evaluate the incidence, characteristics, and outcome of contrast-associated acute kidney injury (CA-AKI) patients using the Risk, Injury, Failure, Loss, and End-stage kidney disease (RIFLE) criteria in critically ill patients in the ICU.MethodsWe conducted a retrospective study of adult patients who underwent contrast-enhanced radiologic tests from January 2011 to December 2012 in a 30-bed medical ICU and a 24-bed surgical ICU.ResultsThe study included 335 patients, and the incidence of CA-AKI was 15.5%. The serum creatinine and estimated glomerular filtration rate values in the CA-AKI patients did not recover even at discharge from the hospital compared with the values prior to the contrast use. Among 52 CA-AKI patients, 55.8% (n = 29) had pre-existing kidney injury and 44.2% (n = 23) did not. The CA-AKI patients were divided into risk (31%), injury (31%), and failure (38%) by the RIFLE classification. The percentage of patients in whom AKI progressed to a more severe form (failure, loss, end-stage kidney disease) increased from 38% to 45% during the hospital stay, and the recovery rate of AKI was 17% at the time of hospital discharge. Because the Acute Physiology and Chronic Health Evaluation (APACHE) II score was the only significant variable inducing CA-AKI, higher APACHE II scores were associated with a higher risk of CA-AKI. The ICU and hospital mortality of patients with CA-AKI was significantly higher than in patients without CA-AKI.ConclusionsCA-AKI is associated with increases in hospital mortality, and can be predicted by the APACHE score.Trial registrationNCT01807195 on March. 06. 2013.

Accidental intradural injection during attempted epidural block -A case report-

Several cases of accidental subdural injection have been reported, but only few of them are known to be accidental intradural injection during epidural block. Therefore we would like to report our experience of accidental intradural injection. A 68-year-old female was referred to our pain clinic due to severe metastatic spinal pain. We performed a diagnostic epidural injection at T9/10 interspace under the C-arm guided X-ray view. Unlike the usual process of block, onset was delayed and sensory dermatomes were irregular range. We found out a dense collection of localized radio-opaque contrast media on the reviewed X-ray findings. These are characteristic of intradural injection and clearly different from the narrow wispy bands of contrast in the subdural space.

The effects of perioperative anesthesia and analgesia on immune function in patients undergoing breast cancer resection: A prospective randomized study

Introduction: Perioperative anesthesia and analgesia exacerbate immunosuppression in immunocompromised cancer patients. The natural killer (NK) cell is a critical part of anti-tumor immunity. We compared the effects of two different anesthesia and analgesia methods on the NK cell cytotoxicity (NKCC) in patients undergoing breast cancer surgery. Methods: Fifty patients undergoing breast cancer resection were randomly assigned to receive propofol-remifentanil anesthesia with postoperative ketorolac analgesia (Propofol-ketorolac groups) or sevoflurane-remifentanil anesthesia with postoperative fentanyl analgesia (Sevoflurane-fentanyl group). The primary outcome was NKCC, which was measured before and 24 h after surgery. Post-surgical pain scores and inflammatory responses measured by white blood cell, neutrophil, and lymphocyte counts were assessed. Cancer recurrence or metastasis was evaluated with ultrasound and whole body bone scan every 6 months for 2 years after surgery. Results: The baseline NKCC (%) was comparable between the two groups (P = 0.082). Compared with the baseline value, NKCC (%) increased in the Propofol-ketorolac group [15.2 (3.2) to 20.1 (3.5), P = 0.048], whereas it decreased in the Sevoflurane-fentanyl group [19.5 (2.8) to 16.4 (1.9), P = 0.032]. The change of NKCC over time was significantly different between the groups (P = 0.048). Pain scores during 48 h after surgery and post-surgical inflammatory responses were comparable between the groups. One patient in the Sevoflurane-fentanyl group had recurrence in the contralateral breast and no metastasis was found in either group. Conclusions: Propofol anesthesia with postoperative ketorolac analgesia demonstrated a favorable impact on immune function by preserving NKCC compared with sevoflurane anesthesia and postoperative fentanyl analgesia in patients undergoing breast cancer surgery.