Non-paroxysmal junctional tachycardia complicating disseminated intravascular coagulation during massive surgical hemorrhage: A case report.

RATIONALE: Non-paroxysmal junctional tachycardia (NPJT) is a self-limiting supraventricular tachycardia associated with primary heart disease, cardiac surgery, digitalis toxicity, and metabolic or electrolyte imbalances. However, NPJT caused enhanced normal automaticity even in the absence of structural heart disease can be fatal if not managed properly. PATIENT CONCERNS: A 74-year-old hypertensive female patient was scheduled for transureteroureterostomy and right ureteroneocystostomy under general anesthesia. DIAGNOSIS: The patient developed NPJT without visible P wave and severe hypotension due to adrenergic stimulation in response to massive hemorrhage during surgery. INTERVENTIONS: NPJT with hypotension was initially converted to sinus rhythm with normotension with administration of adenosine and esmolol. However uncontrolled surgical hemorrhage and administration of large dose of vasopressors eventually perpetuated NPJT refractory to antiarrhythmic drugs. OUTCOMES: Despite intravenous fluid resuscitation and massive transfusion, the patient was deteriorated hemodynamically due to uncontrolled bleeding and persistent NPJT, which resulted in hypovolemic shock and fatal disseminated intravascular coagulation (DIC). LESSONS: NPJT can occur by enhanced automaticity due to increased catecholamine during severe surgical hemorrhage. Although NPJT is generally self-limiting, it can be refractory to antiarrhythmic agents and accelerate hypotension if the surgical bleeding is uncontrolled. Therefore, aggressive management of the primary pathologic condition is crucial for the management of NPJT and hemodynamic collapse even in the absence of structural heart disease.

50% effective concentration of sevoflurane for immobility in cerebral palsy children undergoing botulinum toxin injection.

BACKGROUND: This prospective study aimed to determine the optimum end-tidal sevoflurane concentration required for immobility during botulinum toxin injection in spontaneously breathing children with cerebral palsy (CP). METHODS: Twenty-three children with spastic CP, aged 3 to 12 years, with American Society of Anesthesiologists (ASA) physical status I and II, scheduled to receive botulinum toxin type A injection were enrolled in the study. After induction of deep sedation using pre-filled 8% sevoflurane in oxygen and maintenance of the predetermined end-tidal sevoflurane concentration, the botulinum toxin was injected in spontaneously breathing children. The response to the botulinum toxin injection was classified as "movement" or "no movement" by an independent investigator who was blinded to the predetermined end-tidal sevoflurane concentration and bispectral index (BIS) value. The end-tidal sevoflurane concentration was predetermined, initiating at 2.0% with 0.2% as a step size in the next patient depending on the previous patient's response using the modified Dixon's up-and-down method. RESULTS: Of 21 children, 12 (57.1%) showed "no movement" in response to the botulinum toxin injection. By Dixon's up-and-down method, the 50% effective end-tidal concentration (EC50) of sevoflurane for successful botulinum toxin injection was 1.76 ± 0.15% (95% CI 1.62-1.90). Based on the dose-response curve using probit analysis, the predicted EC50 and 95% effective end-tidal concentrations (EC95) of sevoflurane without movement were 1.77% (95% CI 1.59-2.35) and 2.09% (95% CI 1.89-5.80), respectively. CONCLUSION: Botulinum toxin injection can be successfully accomplished at an end-tidal sevoflurane concentration of 1.76 ± 0.15% in 50% of spontaneously breathing children with CP aged 3-12 years.

Desflurane and remifentanil anesthesia in a child with citrin deficiency: A case report.

RATIONALE: Hyperammonemia, metabolic derangement, and/or the prolonged effects of anesthetics may lead to delayed emergence from general anesthesia as well as the onset of type 2 citrullinemia, even in compensated patients with citrin deficiency. PATIENT CONCERN: A 5-year-old girl with citrin deficiency was scheduled for blepharoplasty under general anesthesia. She developed hyperammonemia with temporary interruption of medication for a few days before surgery. DIAGNOSIS: The patient was genetically diagnosed as citrin deficiency with a mutation in the SLC25A13 gene via newborn screening for metabolic disorders. Her citrulline and ammonia levels were well-controlled with arginine medication and protein-rich diet. Her elevated ammonia level by temporary interruption of medication was corrected with resumption of arginine medication and protein-rich diet before surgery. INTERVENTIONS: We used desflurane and remifentanil for general anesthesia to avoid hyperammonemia and delayed emergence. End-tidal desflurane concentration and anesthetic depth were carefully monitored to avoid excessive anesthesia. OUTCOMES: She recovered consciousness with slightly increased ammonia level immediately after anesthesia. LESSIONS: General anesthesia of the shortest duration with the least metabolized drugs using desflurane and remifentanil, would be beneficial for rapid emergence in surgical patients with citrin deficiency. Maintenance of nitrogen scavenging medication, a protein-rich diet, and serial measurement of ammonia levels in the perioperative period are also important for avoiding hyperammonemia-related neurological dysfunction.

Delayed emergence from propofol anesthesia in a patient with Lesch-Nyhan syndrome: A case report.

RATIONALE: Lesch-Nyhan syndrome (LNS) is an X-linked recessive disorder presenting with uric acid overproduction, neurocognitive disability, and behavioral disturbances. Inhalational anesthesia has been frequently used in LNS patients undergoing surgery. Characteristic compulsive self-injurious behavior and high risk of emesis may hinder inhalational induction. Propofol may be beneficial for these patients because of its easy and rapid titration for anesthetic depth during induction, early recovery from anesthesia, and antiemetic effect as well as uricosuric effect. PATIENT CONCERNS: A 16-year-old male adolescent was scheduled for percutaneous nephrolithotomy. He exhibited poorly controlled muscle, self-injurious behaviors and intellectual disability. DIAGNOSIS: The patient presented with neurodevelopmental delay in the first year of life, and was diagnosed with LNS, with a substitution of phenylalanine to leucine in hypoxanthine-guanine phosphoribosyltransferase (HPRT) 1 gene on the X-chromosome at 3 years of age. INTERVENTIONS: Total intravenous anesthesia was used for induction and maintenance of anesthesia with propofol and remifentanil using target-controlled infusion. OUTCOMES: Time to recovery of consciousness was prolonged after uneventful surgery. Serum uric acid levels gradually increased during postoperative period. LESSONS: Propofol anesthesia using target-controlled infusion does not provide significant clinical advantages in rapid emergence from anesthesia and management of hyperuricemia in LNS patients undergoing urological surgery.

Drug selection for sedation and general anesthesia in children undergoing ambulatory magnetic resonance imaging.

The demand for drug-induced sedation for magnetic resonance imaging (MRI) scans have substantially increased in response to increases in MRI utilization and growing interest in anxiety in children. Understanding the pharmacologic options for deep sedation and general anesthesia in an MRI environment is essential to achieve immobility for the successful completion of the procedure and ensure rapid and safe discharge of children undergoing ambulatory MRI. For painless diagnostic MRI, a single sedative/anesthetic agent without analgesia is safer than a combination of multiple sedatives. The traditional drugs, such as chloral hydrate, pentobarbital, midazolam, and ketamine, are still used due to the ease of administration despite low sedation success rate, prolonged recovery, and significant adverse events. Currently, dexmedetomidine, with respiratory drive preservation, and propofol, with high effectiveness and rapid recovery, are preferred for children undergoing ambulatory MRI. General anesthesia using propofol or sevoflurane can also provide predictable rapid time to readiness and scan times in infant or children with comorbidities. The selection of appropriate drugs as well as sufficient monitoring equipment are vital for effective and safe sedation and anesthesia for ambulatory pediatric MRI.

Validity of bispectral index monitoring during deep sedation in children with spastic cerebral palsy undergoing injection of botulinum toxin.

BACKGROUND: This prospective study aimed to determine whether the bispectral index (BIS) is a valid objective tool for differentiating adequate from inadequate deep sedation in spontaneously breathing children with cerebral palsy (CP). METHODS: Propofol was titrated to increase the level of sedation with a continuous infusion of remifentanil at a rate of 0.05 µg/kg/min while maintaining spontaneous ventilation in 22 children with spastic CP, aged 3-18 years. The depth of sedation was assessed using the University of Michigan Sedation Scale (UMSS) and the Modified Observer's Assessment of Alertness and Sedation (MOAAS) scale. Receiver operating characteristic curve analysis was performed to determine the cutoff BIS values for deep sedation, defined as a UMSS score of 3-4 and a MOAAS score of 0-1. RESULTS: The BIS values significantly changed with the increase in the level of sedation across both the UMSS and MOAAS scores (P < 0.001). The BIS values correlated with the UMSS (r = -0.795, P < 0.001) and MOAAS (r = 0.815, P < 0.001) scores. The cutoff BIS value to detect adequate deep sedation in children with CP was 61.5 (UMSS score: sensitivity 0.860, specificity 0.814; MOAAS score: sensitivity 0.794, specificity 0.811). CONCLUSIONS: The BIS value strongly correlates with the clinical sedation scales, such as the UMSS and MOAAS, during deep sedation in children with CP. Therefore, BIS monitoring can be used as a valid tool for assessing the level of propofol sedation in spontaneously breathing children with CP undergoing a botulinum toxin injection.

Anesthetic management for a patient with bronchobiliary fistula after pancreaticoduodenectomy: A case report.

RATIONALE: Perioperative management of patients with bronchobiliary fistula (BBF) is an anesthetic challenge because they typically exhibit poor lung function preoperatively, require meticulous lung isolation intraoperatively and need postoperative respiratory support. PATIENT CONCERNS: A 44-year-old man with a past surgical history of pancreaticoduodenectomy presented fluctuating fever, jaundice, dyspnea and yellowish sputum. Despite intravenous antibiotic treatment and repeated percutaneous drainage, patient showed gradual deterioration with hypoxemia, and uncontrolled pneumonia. DIAGNOSES: The patient was diagnosed with BBF based on the clinical manifestation such as biloptysis with pneumonia, and imaging studies. INTERVENTIONS: Resection of the fistula and bilobectomy was performed under general anesthesia. Avoidance of positive pressure ventilation before lung isolation and precise lung isolation are essential for patients with BBF to protect the unaffected lung. Therefore, rapid sequence induction was performed. Left-sided double-lumen tube was inserted for lung isolation and position of the tube was confirmed by visualization with fiberoptic bronchoscopy. Bile-stained secretion was repeatedly suctioned in trachea and both bronchi during surgery. OUTCOMES: In spite of decrease in SpO2 with institution of one-lung ventilation, the patient's oxygenation was gradually improved as surgery progressed without hemodynamic instability. At the end of surgery, the double-lumen tube was replaced with a single-lumen endotracheal tube for postoperative mechanical ventilation. LESSONS: Absolute lung isolation using double-lumen tube for one-lung ventilation and bronchial toilet during surgery and replacement of single-lumen tube for postoperative respiratory support at the end of surgery are effective to improve oxygenation in patients with BBF.

Comparison of displacement of polyvinyl chloride and silicone leftsided double-lumen tubes during lateral positioning.

BACKGROUND: Compared to an equivalent sized polyvinyl chloride (PVC) double-lumen tube (DLT), a silicone DLT has a shorter endobronchial segment. The aim of this study was to compare the incidence of clinically significant displacement of left-sided PVC and silicone DLTs after a positional change to a lateral position from a supine position and determine its effect on the need for DLT repositioning for successful lung separation in patients undergoing thoracic surgery. METHODS: One hundred eight adult patients requiring one-lung ventilation were randomly divided into group P (PVC DLT, n = 54) and group S (Silicone DLT, n = 54). The position of the DLT was observed before and after lateral positioning to assess the effect of the position change. The incidence of clinically significant displacement (> 10 mm) of DLT was compared between the groups. RESULTS: DLTs were clinically significantly displaced in group P (17/48, 35.4%) and group S (18/52, 34.6%) after lateral positioning (P = 0.933). A proximal displacement (31.3% [group P] and 25.0% [group S]) was more common than distal displacement (4.2% [group P] and 9.6% [group S]), with no significant intergroup difference (P = 0.494). After lateral positioning, critical malposition of DLT with bronchial herniation to the right main bronchus was 8.3% (group P) and 7.9% (group S, P = 0.906). CONCLUSIONS: Left-sided PVC and silicone DLTs produced comparable incidences of clinically significant displacement and, consequently, required similar rates of repositioning for successful lung separation after lateral positioning.

Anesthetic management of the first forearm transplantation in Korea.

Vascularized composite allotransplantation for the forearm is a complex surgical procedure, requiring multidisciplinary collaboration. It is important to provide optimal blood flow to the grafts, effective immunosuppression, and early rehabilitation for graft survival and good functional outcomes. As ischemia-reperfusion injury and substantial but unquantifiable blood loss are inevitable in this type of surgery, anesthetic management should focus on providing adequate hemodynamic management with proper monitoring, and anesthetic and analgesic strategies to prevent vasoconstriction in the graft. In this paper, we describe the anesthetic management of the first forearm transplantation performed in Korea.

Comparison of sevoflurane and propofol anesthesia on the incidence of hyperglycemia in patients with type 2 diabetes undergoing lung surgery.

Background: The type and regimen of anesthesia may affect perioperative hyperglycemia following major surgical stress. This study compared the effects of sevoflurane and propofol on the incidence of hyperglycemia and clinical outcomes in diabetic patients undergoing lung surgery. Methods: This retrospective study included 176 patients with type 2 diabetes mellitus who had undergone lung surgery. Blood glucose levels and clinical outcomes from the preoperative period to the first 2 post-operative days (PODs) were retrospectively examined in patients who received sevoflurane (group S, n= 87) and propofol (group P, n=89) for maintenance of general anesthesia. The primary endpoint was the incidence of persistent hyperglycemia (2 consecutive blood glucose levels >180 mg/dL [10.0 mmol/L]) during the perioperative period. The secondary composite endpoint was the incidence of major postoperative complications and 30-day mortality rate after surgery. Results: Blood glucose levels similarly increased from the preoperative period to the second POD in both groups (p=0.857). Although blood glucose levels at 2 hours after surgery were significantly lower in group P than in group S (p=0.022; 95% confidence interval for mean difference, -27.154 to -2.090), there was no difference in the incidence of persistent hyperglycemia during the perioperative period (group S, 70%; group P, 69%; p=0.816). The composite of major postoperative complications and all-cause in-hospital and 30-day mortality rates were also comparable between the two groups. Conclusion: Sevoflurane and propofol were associated with a comparable incidence of perioperative hyperglycemia and clinical outcomes in diabetic patients undergoing lung surgery.

Decrease in spectral entropy by low tidal volume ventilation-associated severe hypercapnia: a case report.

Severe hypercapnia can be predicted by a decrease in cerebral electrical activity. The authors describe a sudden decrease in spectral entropy due to severe hypercapnia-induced respiratory acidosis in a patient with chronic pulmonary obstructive disease during lung resection. After two and a half hours of low tidal volume ventilation in the lateral position, the state entropy suddenly dropped from 45 to 7, without any changes in the effect-site concentration of propofol, end-tidal carbon dioxide (CO2) tension, oxygen saturation, or arterial pressure. However, arterial blood gas analysis showed severe respiratory acidosis (pH 7.01, PaCO2 115 mmHg and PaO2 246 mmHg with FIO2 of 0.5). Immediate hyperventilation improved the state entropy and acid-base balance. Electroencephalography-based spectral entropy can detect severe hypercapnia in chronic pulmonary obstructive disease patients with a large arterial to end-tidal CO2 difference due to prolonged hypoventilation during thoracic surgery.

The effect of ketorolac and dexamethasone on the incidence of sore throat in women after thyroidectomy: a prospective double-blinded randomized trial.

BACKGROUND: We evaluated the effect of two drugs with anti-inflammatory action, dexamethasone and ketorolac, on reduction of postoperative sore throat (POST) after general anesthesia with endotracheal intubation in patients undergoing thyroidectomy. METHODS: One hundred and ninety-two female patients scheduled to undergo general anesthesia with endotracheal intubation for thyroidectomy were enrolled in this prospective study. Participants were randomly allocated to receive intravenous medication; placebo (Group C, n = 45), ketorolac 30 mg immediately before intubation (Group Kpre, n = 47), ketorolac 30 mg at the end of surgery (Group Kpost, n = 45) and dexamethasone 10 mg (Group D, n = 43). The incidence and severity of POST and hoarseness were evaluated at 1, 6 and 24 hours after surgery. RESULTS: Incidences and severities of POST at rest and during swallowing in first 6 hours after extubation were comparable among 4 groups. At 24 hours postextubation, the incidence (P = 0.002, 95% CI of proportion differences; 0.05-0.39) and severity (P = 0.008) of POST during swallowing were significantly lower in group D than in group C. Kpre and Kpost groups did not show a greater reduction in POST than group C, despite lower rescue analgesic requirement at 1 hour after extubation in group Kpre (P = 0.006; 95% CI of proportion differences; 0.07-0.38). No intergroup differences were observed in incidences of hoarseness or adverse events. CONCLUSIONS: Intravenous administration of dexamethasone 10 mg, but not ketorolac, before induction of anesthesia reduces the incidence and severity of POST during swallowing at 24 hours after thyroidectomy.

Video Distraction and Parental Presence for the Management of Preoperative Anxiety and Postoperative Behavioral Disturbance in Children: A Randomized Controlled Trial.

BACKGROUND: The anxiolytic efficacy of video watching, in the absence of parents, during the mask induction of anesthesia in young children with high separation anxiety has not been clearly established. We performed this study to determine whether the effect of video distraction on alleviating preoperative anxiety is independent of parental presence and whether a combination of both interventions is more effective than either single intervention in alleviating preoperative anxiety and postoperative behavioral disturbance in preschool children. METHODS: In this prospective trial, 117 children aged 2 to 7 years scheduled for elective minor surgery were randomly allocated to 1 of 3 groups, a video distraction group (group V), a parental presence group (group P), or a combination of video distraction plus parental presence group (group VP) during induction of sevoflurane anesthesia. The Modified Yale Preoperative Anxiety Scale (mYPAS) was used to assess anxiety in the preoperative holding area (baseline), immediately after entry to the operating room, and during mask induction. Compliance during induction, emergence delirium during recovery, and negative behavioral changes at 1 day and 2 weeks postoperatively were also assessed. RESULTS: The mYPAS scores were comparable (P = 0.558), and the number of children exhibiting baseline anxiety (an mYPAS score > 30) were not different among the 3 groups in the preoperative holding area (P = 0.824). After intervention, the changes in mYPAS scores from baseline to induction were not different among the 3 groups (P = 0.049). The proportion of children with increased mYPAS scores was higher in group P compared with group V from baseline to operating room entry (Bonferroni-adjusted 95% confidence interval for difference, 2 to 49) but similar from baseline to induction in all 3 groups. Although children in group V were more cooperative during mask induction than those in the other 2 groups (P < 0.001 versus group P and P = 0.001 versus group VP), no significant intergroup differences were observed in the incidence of emergence delirium or new-onset negative behavioral change after surgery. CONCLUSIONS: Video distraction, parental presence, or their combination showed similar effects on preoperative anxiety during inhaled induction of anesthesia and postoperative behavioral outcomes in preschool children having surgery.

The effects of deep and light propofol anesthesia on stress response in patients undergoing open lung surgery: a randomized controlled trial.

BACKGROUND: This prospective, randomized controlled study was undertaken to compare stress hormone response to open thoracotomy for lung resection at different anesthetic depths, as determined by bispectral index (BIS) monitoring, in patients under propofol-remifentanil anesthesia. METHODS: Forty-eight adult patients scheduled for lung resection surgery using one-lung ventilation were randomly assigned to either a deep anesthesia group (BIS score of 40 ± 5, n = 24) or a light anesthesia group (BIS score of 60 ± 5, n = 24) by adjusting propofol infusion rates. Blood norepinephrine, epinephrine, adrenocorticotropic hormone, and cortisol levels were measured before the induction of anesthesia, at the end of surgery, and at 2 hours postoperatively. Blood glucose, hemodynamic, and oxygenation-ventilation variables, and postoperative outcomes were also measured. RESULTS: Norepinephrine and epinephrine levels remained unchanged over time in the deep group, but norepinephrine levels significantly increased in the light group at 2 h after surgery than at baseline (P = 0.007 and 0.004, respectively). Temporal changes in norepinephrine, but not in epinephrine, were significantly different between the two groups (P = 0.036). Plasma glucose levels in the light group increased with time and were significantly higher than in the deep group at the end of surgery (P = 0.002). CONCLUSIONS: A deep level of anesthesia achieved using high propofol infusion rates during lung surgery provided lower perioperative norepinephrine and glucose responses than light level of anesthesia during the early postoperative period but failed to affect immediate postoperative outcomes.

The effective bolus dose of remifentanil to facilitate laryngeal mask airway insertion during inhalation induction of sevoflurane in children.

PURPOSE: The additional administration of remifentanil during inhalation induction with sevoflurane could provide better conditions for laryngeal mask airway (LMA) insertion than sevoflurane alone. This study was designed to evaluate the 50 % effective bolus dose (ED50) and 95 % effective bolus dose (ED95) of remifentanil required for LMA insertion in children during inhalation induction with sevoflurane. METHODS: Pediatric patients aged 3-12 years requiring general anesthesia were recruited. A predetermined dose of remifentanil was injected over 30 s after the induction of general anesthesia with sevoflurane. LMA insertion was attempted 60 s after remifentanil injection. The dose of remifentanil was determined using the Dixon's up-and-down method, starting from 0.5 µg/kg (step size of 0.05 µg/kg). RESULTS: The study was conducted until seven cross-over points and 29 children were collected. The ED50 of remifentanil for successful LMA insertion during sevoflurane inhalation induction in children was 0.168 ± 0.035 µg/kg using Dixon's method. In addition, the ED50 and ED95 of remifentanil from the probit analysis were 0.176 µg/kg (95 % confidence limits, 0.102-0.216 µg/kg) and 0.268 µg/kg (95 % confidence limits, 0.223-0.659 µg/kg), respectively. CONCLUSION: The ED50 and ED95 of remifentanil for successful LMA insertion in children were estimated to be 0.176 (0.168) and 0.268 µg/kg during inhalation induction with 2.1 % sevoflurane.

Misinsertion of central venous catheter into the suspected vertebral vein: a case report.

We experienced a case in which a central venous catheter (CVC) was misplaced into the wrong vein, which was mistaken for the internal jugular vein (IJV), identified by chest x-ray and ultrasound. The vertebral vein passes through the transverse foramina from the atlas to the 6th cervical vertebra. After exiting the transverse foramen of the 6th vertebra, the vein subsequently runs anterolateral to the vertebral artery and posterior to the IJV and drains the innominate vein. In this case, chest x-ray and ultrasound revealed that the inserted CVC had a course very similar to the vertebral vein. The misplacement of a CVC into the vertebral vein might occur from excessive rotation of the patient's head, which leads to alterations in the cervical vascular anatomy, and from deep insertion of the puncture needle. Therefore, it is advised, for safe CVC insertion, to minimize a patient's head rotation and to make use of ultrasound when the anatomical structures cannot be clearly identified.

A comparison of posterior and medial cord stimulation for neurostimulation-guided vertical infraclavicular block: a randomized noninferiority clinical trial.

BACKGROUND: We investigated whether medial cord stimulation is inferior to posterior cord stimulation for vertical infraclavicular block with respect to block success. METHODS: Ninety-six patients scheduled for upper limb surgery were randomly elicited a medial or posterior cord response for infraclavicular block using 40 mL of 0.5% ropivacaine. We assessed block success (complete sensory block of the 5 nerves in the forearm at 50 minutes) as the primary end point and block procedure characteristics and adverse events as secondary end points. RESULTS: The block success rates did not differ significantly between medial and posterior cord stimulation (95.7% [44/46] vs 91.7% [44/48], 95% CI of difference, -7.4% to 15.6%), while the secondary end points were comparable in both groups. CONCLUSIONS: Needle manipulation to elicit medial cord response is noninferior to posterior cord response of block success during neurostimulation-guided vertical infraclavicular block.

Transient hemidiaphragmatic paresis after ultrasound-guided lateral sagittal infraclavicular block.

As compared with medial approaches for the infraclavicular brachial plexus block, lateral approaches generally have no impact on the phrenic nerve or pulmonary function. A patient experienced transient hemidiaphragmatic paresis after ultrasound-guided lateral sagittal infraclavicular block for lower arm surgery. An accessory phrenic nerve, ie, an anatomical variation, may have been the mechanism of transient hemidiaphragmatic paresis in this patient.

Increased tissue transglutaminase activity contributes to central vascular stiffness in eNOS knockout mice.

Nitric oxide (NO) can modulate arterial stiffness by regulating both functional and structural changes in the arterial wall. Tissue transglutaminase (TG2) has been shown to contribute to increased central aortic stiffness by catalyzing the cross-linking of matrix proteins. NO S-nitrosylates and constrains TG2 to the cytosolic compartment and thereby holds its cross-linking function latent. In the present study, the role of endothelial NO synthase (eNOS)-derived NO in regulating TG2 function was studied using eNOS knockout mice. Matrix-associated TG2 and TG2 cross-linking function were higher, whereas TG2 S-nitrosylation was lower in the eNOS(-/-) compared with wild-type (WT) mice. Pulse-wave velocity (PWV) and blood pressure measured noninvasively were elevated in the eNOS(-/-) compared with WT mice. Intact aortas and decellularized aortic tissue scaffolds of eNOS(-/-) mice were significantly stiffer, as determined by tensile testing. The carotid arteries of the eNOS(-/-) mice were also stiffer, as determined by pressure-dimension analysis. Invasive methods to determine the PWV-mean arterial pressure relationship showed that PWV in eNOS(-/-) and WT diverge at higher mean arterial pressure. Thus eNOS-derived NO regulates TG2 localization and function and contributes to vascular stiffness.

A randomized comparison of ropivacaine 0.1% and 0.2% for continuous interscalene block after shoulder surgery.

BACKGROUND: The optimal concentration of ropivacaine for continuous interscalene block after shoulder surgery is currently unknown. METHODS: Fifty-six patients received a perineural infusion of either ropivacaine 0.1% or 0.2% for 48 hours after shoulder surgery. We assessed pain scores as primary end points and supplemental analgesia, ropivacaine consumption, motor block, side effects, and patient satisfaction as secondary end points. RESULTS: Pain scores were not statistically different during the infusion periods; however, supplemental analgesia consumption was higher in the group receiving ropivacaine 0.1% during the first 24 hours (64% vs 28%, P = 0.022). Other secondary end points were statistically inconclusive. CONCLUSIONS: These results suggest that ropivacaine 0.2% provides more effective analgesia than ropivacaine 0.1% during the first 24 hours for continuous interscalene block after shoulder surgery.