Inhibition of Oxidative Stress in Renal Ischemia-Reperfusion Injury.

BACKGROUND: Superoxide, nitric oxide (NO), and peroxynitrite are important mediators in the pathogenesis of ischemia-reperfusion (I/R) injury. We tested the renoprotective effects of allopurinol (ALP), a xanthine oxidase inhibitor, N-nitro-L-arginine methyl ester (L-NAME), and 5,10,15,20-tetrakis (N-methyl-4-pyridyl) porphyrinato iron (III) (FeTMPyP) by selective inhibition of superoxide, NO, and peroxynitrite, respectively. METHODS: Male Sprague-Dawley rats were randomly assigned to 5 groups (n = 6 per group). Group 1 was a sham-operated group. Group 2 was the renal I/R group (30-minute ischemia followed by 24-hour reperfusion). Rats in groups 3, 4, and 5 received ALP, L-NAME, or FeTMPyP, respectively, at 5 minutes before the reperfusion. Serum creatinine (Cr), blood urea nitrogen (BUN), renal tissue malondialdehyde, superoxide dismutase, histological changes, apoptosis, and monocyte infiltration were evaluated. In addition, the combined treatment with ALP and L-NAME was compared with FeTMPyP in a second independent experiment. RESULTS: The administration of ALP, L-NAME, and FeTMPyP diminished the increase in Cr (P = .0066 for all) and BUN (P = .0066 for ALP; and P = .013 for L-NAME) induced by I/R injury and decreased the histological damage (P = .0066 for all). In addition, ALP, L-NAME, and FeTMPyP attenuated the oxidative stress response as determined by a decrease in malondialdehyde level (P = .0066 for all), apoptotic renal tubular cells (P = .0066 for all), and monocyte infiltration (P = .0066 for all). The combined treatment of ALP and L-NAME decreased Cr and BUN levels to a greater degree than FeTMPyP (P = .016 for Cr; P = .0079 for BUN). CONCLUSIONS: Superoxide, NO, and peroxynitrite are involved in renal I/R injury. The reduction of peroxynitrite formation, via inhibition of superoxide or NO, or the induction of peroxynitrite decomposition may be beneficial in renal I/R injury.

Effect of local wound infiltration and transversus abdominis plane block on morphine use after laparoscopic colectomy: a nonrandomized, single-blind prospective study.

BACKGROUND: Recently, nonopioid-based treatment modalities have been used to improve analgesia and decrease opioid-related side effects after surgery. Transversus abdominis plane (TAP) block and local infiltration of the surgical wound are commonly used multimodal analgesia techniques after abdominal surgery; however, few studies have compared the effectiveness of a TAP block with that of local infiltration of surgical wounds in patients who have undergone laparoscopic colorectal surgery. MATERIALS AND METHODS: Sixty patients undergoing laparoscopic colorectal surgery participated in this prospective comparative study. All patients were allocated to 1 of 2 groups as follows: the TAP group or the infiltration group. Patients in the TAP group received bilateral TAP blocks at the end of the surgery. Patients in the infiltration group received local infiltration of anesthetics in the surgical wounds after closure of the peritoneum. All patients received postoperative analgesia with morphine as a patient-controlled analgesia. Opioid consumption and pain scores were recorded at 2, 6, 24, and 48 h after the operation. RESULTS: The characteristics of patients in the TAP group (n = 30) and local infiltration group (n = 29) were comparable. Pain scores while coughing and at rest were not different between the two groups. Postoperative morphine use was significantly reduced in the TAP group compared with that in the local infiltration group at 2-6 h (2.9 ± 1.9 mg versus 4.5 ± 3.2 mg, P = 0.02), 6-24 h (5.5 ± 3.3 mg versus 10.2 ± 8.4 mg, P = 0.00), the first 24 h (16.6 ± 6.6 mg versus 24.0 ± 9.7 mg), and 48 h (23.6 ± 8.2 mg versus 31.8 ± 12.5 mg, P = 0.00). No differences in rescue analgesic use or side effects were noted between the groups. CONCLUSIONS: Compared with local anesthetic infiltration, bilateral TAP blocks decreased the cumulative morphine use at 24 h and 48 h postoperatively in patients who had undergone laparoscopic colorectal surgery.

Clinical usefulness of fracture site in situ block on lumbar spine transverse process fracture.

Lumbar spine transverse process fractures (LSTPFs) are uncommon and frequently overlooked on plain film radiographs. Even when recognized, they are often regarded as trivial and minimally painful injuries compared with combined serious major abdominal, pelvic, and spinal injuries. Conservative treatments are usually offered to patients with LSTPFs. This report presents 4 cases of LSTPFs where symptoms did not improve after more than 1 week of conservative management. Local anesthetics and steroids were injected directly into the fracture site under computed tomography guidance, referred to as a fracture site in situ block, in an attempt to accelerate the return to daily lives and professional activities. Three of the 4 patients returned to their daily lives almost immediately after completing the procedure. Although the procedure was appropriately performed at L4, 1 patient still complained of pain. This patient's all films were meticulously re-examined, and it was determined that a transverse process fracture was present at not only L4 but also L1. This report introduces a method of active treatment to help patients with LSTPFs quickly return to their daily lives and professional activities. The positive results in these cases suggest that fracture site in situ block might be a useful option for treating patients with LSTPFs.

Anesthetic management for inhibiting sympathetic activation in an adolescent patient diagnosed with catecholaminergic polymorphic ventricular tachycardia and undergoing left cardiac sympathetic denervation: A case report.

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a genetic disorder in which catecholamine release during exercise or emotional stress cause fatal tachyarrhythmias. In this paper, we discuss methods to minimize the sympathetic stimulation that can occur during the perioperative period in patients undergoing left cardiac sympathetic denervation to surgically treat CPVT.

Effect of Minimum Bronchial Cuff Volume of Left-Sided Double-Lumen Tube for One-Lung Ventilation on the Change in Bronchial Cuff Pressure during Lateral Positioning in Thoracic Surgery: A Prospective Observational Study.

The minimum bronchial cuff volume (BCVmin) of a double-lumen tube (DLT) without air leaks during lung isolation may vary among individuals, and lateral positioning could increase the bronchial cuff pressure (BCP). We investigated the effect of initially established BCVmin (BCVi) on the change in BCP by lateral positioning. Seventy patients who underwent elective lung surgery were recruited and divided into two groups according to the BCVi obtained during anesthetic induction in each patient. Outcome analysis was conducted using data from 39 patients with a BCVi greater than 0 (BCVi > 0 group) and 27 with a BCVi of 0 (BCVi = 0 group). The primary outcome was a change in the value measured in the supine and lateral positions of the initially established BCP (BCPi; BCP at the time of BCVi injection), which was significantly larger in the BCVi > 0 group than in the BCVi = 0 group (1.5 (0.5-6.0) cmH2O vs. 0.0 (0.0-1.0) cmH2O; p < 0.001). BCVi was related to the left main bronchus (LMB) diameter (Spearman's rho = 0.676, p < 0.001) and the gap between the LMB diameter and the outer diameter of the bronchial cuff (Spearman's rho = 0.553, p < 0.001). Therefore, selecting a DLT size with a bronchial cuff that fits each patient's LMB may be useful in minimizing the change in BCP when performing lateral positioning during thoracic surgery. If the bronchial cuff requires unavoidable initial inflation, it is necessary to be aware that BCP may increase during lateral positioning and to monitor the BCP regularly if possible.

Suspected Malignant Hyperthermia in a Brain-Dead Donor During Anesthesia for Organ Procurement Surgery: A Case Report.

We report an unusual case of highly suspected malignant hyperthermia after inducing anesthesia in a brain-dead 18-year-old male patient undergoing organ procurement surgery. The patient was administered desflurane (3 vol%) and rocuronium bromide (50 mg) to induce and maintain general anesthesia. He experienced hypercapnia and tachycardia within 5 minutes of anesthesia induction; however, his body temperature rapidly rose only after 15 minutes. The volatile anesthetic was discontinued, and dantrolene was administered at a low dose (1 mg/kg) to avert possible hepatotoxic effects on the donor liver. Fortunately, the clinical course of the brain-dead donor until the organs were harvested and the liver transplantation outcome of the recipient was favorable. A comprehensive understanding of the pathophysiology of brain death, organ transplantation, and malignant hyperthermia is essential to respond promptly and appropriately. Based on our experience, low-dose dantrolene may be clinically used in brain-dead donors while accounting for its potential hepatotoxic effects.

Effects of remote ischemic postconditioning on hepatic injury in lipopolysaccharide-induced endotoxemic rats.

BACKGROUND: Remote ischemic postconditioning (RIPoC) is induced by several cycles of brief, reversible, mechanical blood flow occlusion, and reperfusion of the distal organs thereby protecting target organs. We investigated if RIPoC ameliorated liver injury in a lipopolysaccharide (LPS)-induced endotoxemic rats. METHODS: Protocol 1) Rats were administered LPS and samples collected at 0, 2, 6, 12, and 18 h. 2) After RIPoC at 2, 6, and 12 h (L+2R+18H, L+6R+18H, and L+12R+18H), samples were analyzed at 18 h. 3) RIPoC was performed at 2 h, analysis samples at 6, 12, 18 h (L+2R+6H, L+2R+12H, L+2R+18H), and RIPoC at 6 h, analysis at 12 h (L+6R+12H). 4) Rats were assigned to a control group while in the RIPoC group, RIPoC was performed at 2, 6, 10, and 14 h, with samples analyzed at 18 h. RESULTS: Protocol 1) Liver enzyme, malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), and nuclear factor-κB (NF-κB) levels increased while superoxide dismutase (SOD) levels decreased over time. 2) Liver enzyme and MDA levels were lower while SOD levels were higher in L+12R+18H and L+6R+18H groups when compared with L+2R+18H group. 3) Liver enzyme and MDA levels were lower while SOD levels were higher in L+2R+6H and L+6R+12H groups when compared with L+2R+12H and L+2R+18H groups. 4) Liver enzyme, MDA, TNF-α, and NF-κB levels were lower while SOD levels were higher in RIPoC group when compared with control group. CONCLUSIONS: RIPoC attenuated liver injury in the LPS-induced sepsis model by modifying inflammatory and oxidative stress response for a limited period.

Effect of Dexmedetomidine Preconditioning on Hepatic Ischemia-Reperfusion Injury in Acute Hyperglycemic Rats.

BACKGROUND: Acute hyperglycemia frequently occurs in stressful situations, including liver transplantation or hepatic surgery, which may affect the protective effects of dexmedetomidine preconditioning and increase postoperative mortality. Therefore, this study aimed to investigate the effects of dexmedetomidine on hepatic ischemia-reperfusion injury in acute hyperglycemia. METHODS: Thirty-six Sprague-Dawley rats were randomly assigned to 6 groups, including a combination between 2 glycemic (normo- and hyperglycemia) and 3 ischemia-reperfusion conditions (sham, ischemia-reperfusion only, and dexmedetomidine plus ischemia-reperfusion). Dexmedetomidine 70 µg/kg was preconditioned 30 minutes before ischemic injury. After 6 hours of reperfusion, serum aminotransferase levels were measured to confirm the hepatic tissue injury. Furthermore, inflammatory (nuclear factor-κb, tumor necrosis factor-α, and interleukin-6) and oxidative stress markers (malondialdehyde and superoxide dismutase) were detected. RESULTS: Ischemia-reperfusion injury significantly increased the serum levels of aminotransferase and inflammatory and oxidative stress markers. These ischemia-reperfusion-induced changes were further exacerbated in hyperglycemia and were significantly attenuated by dexmedetomidine preconditioning. However, the effects of dexmedetomidine in hyperglycemia were lesser than those in normoglycemia (P < .05 for aminotransferases, inflammatory markers, malondialdehyde, and superoxide dismutase). CONCLUSIONS: These findings suggest that the protective effects of dexmedetomidine preconditioning may be intact against hepatic ischemia-reperfusion injury in acute hyperglycemia. Although its effects appeared to be relatively reduced, this may be because of the increase in oxidative stress and inflammatory response caused by acute hyperglycemia. To determine whether the effects of dexmedetomidine itself would be impaired in hyperglycemia, further study is needed.

Infection prevention measures and outcomes for surgical patients during a COVID-19 outbreak in a tertiary hospital in Daegu, South Korea: a retrospective observational study.

BACKGRUOUND: The first large coronavirus disease 2019 (COVID-19) outbreak outside China occurred in Daegu. In response, we developed infection prevention measures for surgical patients during the outbreak at our hospital and retrospectively reviewed the outcomes of COVID-19-related surgical patients. METHODS: We reviewed the medical records of 118 COVID-19-related surgical patients and monitored their clinical outcomes until March 31, 2021. We also interviewed healthcare workers who participated in their perioperative care at Kyungpook National University Chilgok Hospital. The perioperative management guidelines for COVID-19-related patients were prepared through multidisciplinary discussions, including the infection control department, surgical departments, and anesthesiology department before and during the COVID-19 outbreak. RESULTS: One standard operating room was temporarily converted to a negative-pressure room by increasing the exhaust air volume, creating a relative pressure of -11.3 Pa. The healthcare workers were equipped with personal protective equipment according to the patient's classification of the risk of COVID-19 transmission. The 118 COVID-19-related patients underwent emergent surgery in the negative-pressure room, including three COVID-19-confirmed patients and five COVID-19-exposed patients. CONCLUSION: All surgeries of the COVID-19-related patients were performed without specific adverse events or perioperative COVID-19 transmission. Our experience setting up a negative-pressure operating room and conservative perioperative protocol to prevent COVID-19 transmission will help plan and execute infection control measures in the future.

N-Acetyl-l-Cysteine Attenuates Ischemia/Reperfusion Injury-Induced Allodynia and N-Methyl-d-Aspartate Receptor Activation in Rats.

BACKGROUND: Although reactive oxygen species (ROS) are believed to be involved in pathogenic mechanisms that underlie complex regional pain syndrome type I (CRPS-I), the role of ROS in the central mechanism of CRPS is not fully understood. OBJECTIVE: In this study we investigated whether ROS scavenger N-acetyl-l-cysteine (NAC) was capable of attenuating mechanical allodynia and whether pain was decreased through modulating N-methyl-d-aspartate (NMDA) receptor activation in a chronic postischemia pain (CPIP) animal model that mimics the symptoms of CRPS-I. METHODS: Thirty male Sprague-Dawley rats were randomly allocated to 5 different groups: (1) sham rats and CPIP rats treated with (2) vehicle; (3) NAC 30 mg/kg; (4) NAC 100 mg/kg; and (5) NAC 300 mg/kg intraperitoneally at 15 minutes before reperfusion. CPIP was generated after a 3-hour ischemia/reperfusion injury on the hind limb using a tight fitting O-ring. Then, mechanical paw-withdrawal thresholds to von Frey stimuli were assessed before ischemia (baseline), at 4 hours; 1, 3, and 5 days; and 1, 2, 3, and 4 weeks after reperfusion. Another set of 5 animal groups in the same categories was used to determine phosphorylated NMDA receptor 1 subunit (pNR1) immunoreactivity in the ipsilateral L4/6 spinal cord at 3 days after reperfusion. RESULTS: The sham group showed no significant difference in pain thresholds over 4 weeks. With NAC treatment, the pain thresholds measured after reperfusion increased significantly, and this increase lasted 4 weeks after reperfusion compared with the vehicle group (P < 0.01 on the ipsilateral side and P < 0.05 on the contralateral side). The relative density of pNR1 at 3 days after reperfusion in NAC-treated rats decreased significantly compared with that of the vehicle group (all, P < 0.001). The NAC dose was significantly correlated not only with paw-withdrawal threshold (ρ = 0.979; P < 0.001) but also with the relative density of pNR1 (ρ = -0.875; P < 0.001). CONCLUSIONS: NAC, administered during the pre-reperfusion period, had a long-term antiallodynic effect through the attenuation of NMDA receptor phosphorylation, leading to central sensitization.

The Role of Dexmedetomidine in Hepatic Ischemia-Reperfusion Injury Via a Nitric Oxide-Dependent Mechanism in Rats.

BACKGROUND: Dexmedetomidine is known to protect against ischemia-reperfusion (IR) in various organs; however, the mechanisms of dexmedetomidine in the liver remain unclear. We investigated whether dexmedetomidine preconditioning leads to hepatic protection and whether nitric oxide was associated with this protective mechanism by employing N-nitro-l-arginine methyl ester (l-NAME), a nitrous oxide synthase inhibitor. METHODS: Experiment 1 included 24 rats in 4 groups: sham, IR, 30 µg/kg of dexmedetomidine, and 50 µg/kg of dexmedetomidine. Experiment 2 included 36 rats in 6 groups: IR, 50 µg/kg of dexmedetomidine, 10 mg/kg of l-NAME, 10 mg/kg of l-NAME + 50 µg/kg of dexmedetomidine, 30 of mg/kg l-NAME, and 30 mg/kg of l-NAME + 50 µg/kg of dexmedetomidine. All drugs were administered intraperitoneally. The levels of serum transaminases, malondialdehyde, superoxide dismutase, tumor necrosis factor-α, nuclear factor-κB, and c-Jun N-terminal kinase were measured 6 hours after hepatic surgery. RESULTS: Dexmedetomidine demonstrated a dose-dependent decrease in serum transaminase levels. The 50-µg/kg dexmedetomidine group showed a significant decrease in malondialdehyde levels (P = .002), increase in superoxide dismutase levels (P = .002), and a significantly lower level of phosphorylated tumor necrosis factor-α, nuclear factor-κB, and c-Jun N-terminal kinase (P = .002, respectively) compared with the IR injury group. These protective effects of dexmedetomidine were partially reversed by pretreatment with l-NAME (P < .01 for 20 and 30 mg/kg of l-NAME). CONCLUSION: In hepatic IR injury, dexmedetomidine might protect the liver via antioxidative and anti-inflammatory responses, and nitric oxide production could play a role in these protective mechanisms.

Comparison of ramosetron, dexamethasone, and a combination of ramosetron and dexamethasone for the prevention of postoperative nausea and vomiting in Korean women undergoing thyroidectomy: A double-blind, randomized, controlled study.

BACKGROUND: Thyroidectomy is associated with a relatively high incidence of postoperative nausea and vomiting (PONV), ranging from 51% to 76%. Because these symptoms are distressing for patients, prophylactic medication to avoid or reduce PONV is recommended. OBJECTIVE: The aim of the present study was to compare the efficacy of ramosetron, dexamethasone, and a combination of ramosetron and dexamethasone in preventing PONV in Korean women undergoing thyroidectomy. METHODS: In this double-blind, randomized, controlled trial, consecutive adult female patients who were scheduled to undergo thyroidectomy under general anesthesia at the Kyungpook National University Hospital (Daegu, Korea) were randomly assigned to receive ramosetron 0.3 mg alone, dexamethasone 8 mg alone, or a combination of ramosetron 0.3 mg and dexamethasone 8 mg administered intravenously as a single dose immediately after induction of anesthesia. The primary end point of this study was the total PONV rate up to 24 hours postanesthesia. The secondary end points were the incidence of nausea, incidence of vomiting, severity of nausea (0 = no nausea to 10 = nausea as bad as it could be), use of rescue antiemetic drugs, and the occurrence of adverse events (AEs) determined through interview or spontaneous patient report for 24 hours postanesthesia. RESULTS: A total of 198 female patients were approached for study inclusion, 18 of whom were excluded. Therefore, 180 Korean women (mean [SD] age, 46.5 [12.6] years; height, 159.8 [2.7] cm; weight, 53.2 [3.6] kg) were enrolled and completed the study. The total PONV rates up to 24 hours postanesthesia were 35%, 13%, and 10% in the dexamethasone, ramosetron, and combination groups, respectively. The PONV rate was significantly lower in the combination group than in the dexamethasone alone group (P = 0.006). The PONV rate was not significantly different in the combination group compared with the ramosetron alone group. The PONV rate in the dexamethasone alone group was significantly higher than that in the ramosetron alone group (P = 0.03). The severity of nausea (median [25th-75th percentiles], 0 [0-0] vs 0 [0-4]; P = 0.009) and rate of use of rescue antiemetic drugs (5% vs 27%; P = 0.006) were significantly lower in the combination group than in the dexamethasone alone group, whereas the severity of nausea (median [25th-75th percentiles], 0 [0-0] vs 0 [0-0]) and rate of use of rescue antiemetic drugs (5% vs 7%) were not significantly different between the combination and ramosetron alone groups. The severity of nausea (median [25th-75th percentiles], 0 [0-4] vs 0 [0-0]; P = 0.033) and the rate of use of rescue antiemetic drugs (27% vs 7%; P = 0.018) were significantly higher in the dexamethasone alone group than in the ramosetron alone group. The rates of AEs (headache: 15%, 20%, and 18%; dizziness: 18%, 22%, and 15%) were not significantly different in the dexamethasone alone, ramosetron alone, or combination groups, respectively. CONCLUSIONS: The combination of ramosetron and dexamethasone was more effective in reducing PONV than was dexamethasone monotherapy. However, the combination did not show additional benefits compared with ramosetron alone in preventing PONV after thyroidectomy in these Korean women.

Posterior wall penetration of the internal jugular vein during central venous catheter insertion using real-time ultrasound: Two case reports.

RATIONALE: Because central venous catheters (CVCs) are placed at the great vessels, mechanical complications can be fatal. Using the landmark method alone can make CVC difficult to access, depending on the skill of the operator and various patient conditions, such as anatomical variations of the vessels, young age, hypovolemic state, obesity, and short neck. Therefore, ultrasound (US)-guided techniques, including visualization of the vein and needle in the lumen of the vessel, are recommended. Nevertheless, our experience demonstrated that CVC malposition or vascular penetration cannot be prevented completely, even with real-time US guidance. PATIENT CONCERNS: The first patient was a 19-year-old woman (weight = 58 kg, height = 155 cm) who underwent CVC cannulation in the right internal jugular vein (IJV) under general anesthesia using real-time US. The second patient, a 50-year-old woman (weight = 51.6 kg, height = 155.7 cm), underwent CVC insertion in the right IJV using real-time US. DIAGNOSES: During guidewire insertion in the first case, the posterior wall of IJV was penetrated, and a break in the core body of the guidewire was detected. In the case of second patient, CVC was embedded in the posterior wall of IJV and misplaced in the interpleural space in the right thorax. In both cases, an out-of-plane US approach was used. INTERVENTIONS: In the first case, the broken guidewire was completely removed with real-time US guidance. In the second case, all fluid injected through CVC was aspirated, and then CVC was removed. OUTCOMES: In both cases, surgeries were completed successfully and all the patients were discharged without any complications. LESSONS: Even if the needle tip is located in the lumen of IJV and blood aspiration is confirmed on real-time US, vascular penetration or CVC malposition during the procedure cannot be completely prevented because of the limitation of the US imaging field. These results suggest that care must be exercised even during US-guided CVC placement and that alternative US-guided techniques or supplementary monitoring should be considered to confirm proper CVC position.

Analgesic Effect of Ultrasound-Guided Preoperative Unilateral Lateral Quadratus Lumborum Block for Laparoscopic Nephrectomy: A Randomized, Double-Blinded, Controlled Trial.

PURPOSE: The quadratus lumborum block (QLB) is a relatively new regional analgesic technique that could provide analgesia to the abdominal wall and reduce postoperative opioid consumption. We investigated the opioid-sparing effect of a unilateral lateral QLB in laparoscopic nephrectomy. PATIENTS AND METHODS: A total of 60 patients undergoing laparoscopic nephrectomy were included in the study. Patients were randomized into two groups as QLB and control group. QLB group received QLB with 25mL 0.25% ropivacaine, and the control group received 25mL 0.9% saline at anterolateral border of quadratus lumborum muscle preoperatively. Opioid consumption and the pain intensity at rest and on movement were measured at 2nd, 6th, 24th, and 48th hour postoperatively. We also assessed the time to first flatus to measure the extent of paralytic ileus and the quality of recovery-15 (QoR-15) questionnaire. RESULTS: Postoperative opioid consumption was significantly lower in the QLB group than in the control group at 6, 24, and 48h after surgery (P < 0.05). The pain intensity at rest and on movement was significantly lower in the QLB group than in the control group during the first 24 hours after surgery (P < 0.05). The incidence of postoperative nausea and vomiting, time to first flatus, and QoR-15 score did not show significant differences. CONCLUSION: Preoperative unilateral QLB successfully decreased postoperative pain and opioid consumption after laparoscopic nephrectomy and could be an option for analgesia after laparoscopic nephrectomy.

Role of Remote Ischemic Preconditioning in Hepatic Ischemic Reperfusion Injury.

The effect of remote ischemic preconditioning (RIPC) has been proposed that mediates the protective response in ischemia reperfusion injury (IRI) of various organs. In this study, we investigated the effect of RIPC in hepatic IRI, by assessing biomarker of oxidative stress and inflammatory cytokines. Moreover, we intended to demonstrate any such protective effect through nitric oxide (NO). Twenty-five rats were divided into the 5 groups: (1) Sham; (2) RIPC; (3) hepatic IRI; (4) RIPC + hepatic IRI; (5) C-PTIO, 2-(4-carboxyphenyl)-4,5dihydro-4,4,5,5-tetramethyl-1H-imidazolyl-1-oxy-3oxide, + RIPC + hepatic IRI. RIPC downregulated the level of aspartate aminotransferase (AST), alanine aminotransferase (ALT), histologic damage, and activity of Malondialdehyde (MDA). However, there was no significant reduction in the level of tumor necrosis factor-alpha (TNF-α) and nuclear factor kappa B (NF-κB). AST and ALT levels, and hepatic tissue morphology in the C-PTIO group showed a significant improvement compared to those of the RIPC + hepatic IRI group. The application of RIPC before hepatic ischemia downregulated the oxidative stress, not the inflammatory cytokines. Moreover, these protective effect of RIPC would be mediated through the activation of NO as well as anti-oxidant effect.

Reduction of allodynia by intrathecal transplantation of microencapsulated porcine chromaffin cells.

Bovine chromaffin cells (BCCs) are well known to have analgesic effect to reduce acute or chronic pain when transplanted in the subarachnoid space and have been considered as an alternative therapy for pain management. However, due to recent concerns over risks associated with prion transmission, porcine tissue is considered to be an alternate xenogeneic source for clinical use. In the present study, we investigated whether microencapsulated porcine adrenal medullary chromaffin cells (PCCs) also have analgesic effect to reduce allodynia caused by neuropathic pain in chronic constriction injury model of rat. PCCs were isolated from a porcine adrenal medulla and then microencapsulated with alginate and poly. In in vitro tests, the microencapsulated PCCs were investigated whether they have an ability to release catecholamines responding to nicotine stimulation. The levels of catecholamines released from the microencapsulated PCCs were significantly higher than from microencapsulated BCCs. In addition, the microencapsulated PCCs released catecholamines and met-enkephalin responding to cerebral spinal fluid (CSF) retrieved from a neuropathic pain model. In in vivo tests, implantation of microencapsulated PCCs reduced both mechanical and cold allodynia in chronic constriction injury model of a rat whereas the microencapsulated BCCs reduced only cold allodynia under the same conditions. The injection of antagonist of opioid peptides reversed the reduction of cold allodynia in microencapsulated PCC-received animal. The levels of catecholamines in the CSF of rats after implantation of microencapsulated PCCs were significantly higher than in the control group. These data suggest that microencapsulated PCCs may be another effective source for the treatment of neuropathic pain.

Postoperative emergence agitation and intraoperative sevoflurane sedation under caudal block in children: a randomized comparison of two sevoflurane doses.

BACKGROUND: Sub-umbilical surgery under caudal block in conjunction with sevoflurane sedation may be safe in terms of maintaining spontaneous breathing and avoiding complications associated with general anesthesia. However, sevoflurane-induced emergence agitation (EA) continues to be a clinically important phenomenon in children. To compare the incidence of EA in children undergoing sub-umbilical surgery under caudal block with two different doses of sevoflurane. METHODS: Forty children (aged 1-5 years) scheduled to undergo inguinal hernia repair under caudal block with sevoflurane sedation via a face mask were randomized into either the low-dose (1.0%) end-tidal sevoflurane concentration group (Group LS) or the high-dose (2.5%) end-tidal sevoflurane concentration group (Group HS). We monitored EA episodes at 5 and 30 min in the post-anesthetic care unit (PACU) by using the fourpoint agitation scale and the Pediatric Anesthesia Emergence Delirium (PAED) scale. RESULTS: The four-point agitation scale scores and PAED scores were not different between the groups at 5 min. However, the agitation score was higher in Group HS than in Group LS at 30 min after arriving in the PACU. The time required to recover from sedation was longer in Group HS than in Group LS. CONCLUSIONS: Face-mask sedation with 1.0% sevoflurane in conjunction with caudal block may be more effective than that with 2.5% sevoflurane in preventing EA.

Sodium Nitrite Attenuates Hepatic Ischemia-Reperfusion Injury in Rats.

OBJECTIVES: Nitrite as an alternative source of nitric oxide has been proposed, as it can mediate the protective response in the presence of ischemia or hypoxic conditions and inorganic nitrite can be reduced to nitric oxide by xanthine oxidoreductase. Here, we investigated whether pretreatment with sodium nitrite can attenuate liver damage in hepatic ischemia-reperfusion injury and identified the possible mechanism of nitrite reduction using 2-(4-carboxyphenyl)-4,5dihydro-4,4,5,5-tetramethyl-1H-imidazolyl-1-oxy-3oxide (C-PTIO), a nitric oxide scavenger, and allopurinol, a xanthine oxidoreductase inhibitor. MATERIALS AND METHODS: In experiment 1, 30 male Sprague-Dawley rats were divided into 5 groups: (1) sham-operated; (2) hepatic ischemia-reperfusion injury; and (3-5) sodium nitrite administered intra-peritoneally 30 minutes before ischemia at 2.5, 25, and 250 µmol/kg, respectively. In experiment 2, 24 male Sprague-Dawley rats were divided into 4 groups: (1) hepatic ischemia-reperfusion injury; (2) sodium nitrite + hepatic ischemia-reperfusion injury; (3) C-PTIO + sodium nitrite + hepatic ischemia-reperfusion injury; and (4) allopurinol + sodium nitrite + hepatic ischemia-reperfusion injury. Sodium nitrite (25 µmol/kg) was then administered 30 minutes before hepatic ischemia, and C-PTIO or allopurinol was administered 5 minutes before sodium nitrite administration. Blood aspartate aminotransferase, alanine aminotransferase, hepatic tissue malondialdehyde, histologic changes, and expression of mitogen-activated protein kinase family members were evaluated. RESULTS: Sodium nitrite limited serum elevation of alanine aminotransferase and aspartate aminotransferase induced by hepatic ischemia-reperfusion with a peak effect occurring at 25 µmol/kg sodium nitrite. Pre-treatment with allopurinol abolished the protective effect of sodium nitrite, and C-PTIO treatment attenuated the hepatoprotection of sodium nitrite in rats with hepatic ischemia-reperfusion injury. Liver malondialdehyde activity after ischemia-reperfusion decreased in sodium nitrite-treated rats. Sodium nitrite also prevented hepatic ischemia-reperfusion-induced c-Jun N-terminal kinase and extracellular signal-regulated kinase phosphorylation. CONCLUSIONS: Exogenous sodium nitrite had protective effects against hepatic ischemia-reperfusion injury. Catalytic reduction to nitric oxide and attenuation of hepatic ischemia-reperfusion is dependent on xanthine oxidoreductase.

The Effect of Nitric Oxide on Remote Ischemic Preconditioning in Renal Ischemia Reperfusion Injury in Rats.

Although remote ischemic preconditioning (RIPC) is an organ-protective maneuver from subsequent ischemia reperfusion injury (IRI) by application of brief ischemia and reperfusion to other organs, its mechanism remains unclear. However, it is known that RIPC reduces the heart, brain, and liver IRI, and that nitric oxide (NO) is involved in the mechanism of this effect. To identify the role of NO in the protective effect of RIPC in renal IRI, this study examined renal function, oxidative status, and histopathological changes using N-nitro-L-arginine methyl ester (L-NAME), an NO synthase inhibitor. Remote ischemic preconditioning was produced by 3 cycles of 5 minutes ischemia and 5 minutes reperfusion. Blood urea nitrogen, creatinine (Cr), and renal tissue malondialdehyde levels were lower, histopathological damage was less severe, and superoxide dismutase level was higher in the RIPC + IRI group than in the IRI group. The renoprotective effect was reversed by L-NAME. Obtained results suggest that RIPC before renal IRI contributes to improvement of renal function, increases antioxidative marker levels, and decreases oxidative stress marker levels and histopathological damage. Moreover, NO is likely to play an important role in this protective effect of RIPC on renal IRI.

Efficacy of combination intravenous lidocaine and dexamethasone on propofol injection pain: a randomized, double-blind, prospective study in adult Korean surgical patients.

BACKGROUND: Pain on injection is a common adverse effect with propofol used for general anesthesia. OBJECTIVES: The aims of this study were to evaluate the analgesic effect of dexamethasone during propofol injection and investigate whether a combination of dexamethasone and lidocaine produced additional analgesic efficacy compared with either treatment alone. METHODS: In a double-blind, prospective trial, patients scheduled to undergo elective plastic surgery were randomized to receive lidocaine 20 mg, dexamethasone 6 mg, combination lidocaine 20 mg and dexamethasone 6 mg, or normal saline with venous occlusion for 1 minute, followed by administration of 25% of the total calculated dose of propofol (2.5 mg/kg) into a dorsal hand vein. Pain intensity and incidence were evaluated during a 10-second pause before the induction of anesthesia, using a 4-point verbal rating scale (0=none, 1=mild, 2=moderate, 3=severe); a score of 1 to 3 was counted as pain. Patients were monitored hourly for 24 hours postsurgery by a blinded investigator for adverse effects at the injection site (eg, pain, edema, wheal, flare response). RESULTS: A total of 140 (35 per group) Korean patients (91 women, 49 men; mean [SD] age, 47 [14] years; mean [SD] height, 162 [8] cm; and mean [SD] body weight, 60 [8] kg) completed the study. Demographic variables were similar among groups. With respect to pain intensity, mean pain score was significantly less in the combination group than in the lidocaine or dexamethasone groups (P<0.01, respectively), although the median pain scores for all groups were 0. The incidence of pain associated with propofol injection was reduced significantly in the combination group compared with the lidocaine or dexamethasone group (0% vs 34.3% and 37.1%, respectively; both, P<0.01). One patient (in the combination group) complained of perineal itching immediately following injection; however, this subsided within a few seconds and did not require any intervention. No other adverse effects at the injection site were observed in any patient in the 24 hours post surgery. CONCLUSION: Combination lidocaine 20 mg and dexamethasone 6 mg, with venous occlusion for 1 minute, was more effective than lidocaine 20 mg or dexamethasone 6 mg alone for pain control during propofol injection in these Korean patients.