Comparison Between Phenylephrine and Dopamine in Maintaining Cerebral Oxygen Saturation in Thoracic Surgery: A Randomized Controlled Trial

Fluid is usually restricted during thoracic surgery, and vasoactive agents are often administered to maintain blood pressure. One-lung ventilation (OLV) decreases arterial oxygenation; thus oxygen delivery to the brain can be decreased. In this study, we compared phenylephrine and dopamine with respect to maintaining cerebral oxygenation during OLV in major thoracic surgery.Sixty-three patients undergoing lobectomies were randomly assigned to the dopamine (D) or phenylephrine (P) group. The patients’ mean arterial pressure was maintained within 20% of baseline by a continuous infusion of dopamine or phenylephrine. Maintenance fluid was kept at 5 mL/kg/h. The depth of anesthesia was maintained with desflurane 1MAC and remifentanil infusion under bispectral index guidance. Regional cerebral oxygen saturation (rScO₂) and hemodynamic variables were recorded using near-infrared spectroscopy and esophageal cardiac Doppler.The rScO₂ was higher in the D group than the P group during OLV (OLV 60 min: 71 ± 6% vs 63 ± 12%; P = 0.03). The number of patients whose rScO₂ dropped more than 20% from baseline was 0 and 6 in the D and P groups, respectively (P = 0.02). The D group showed higher cardiac output, but lower mean arterial pressure than the P group (4.7 ± 1.0 vs 3.9 ± 1.2 L/min; 76.7 ± 8.1 vs 84.5 ± 7.5 mm Hg; P = 0.02, P = 0.02). Among the variables, age, hemoglobin concentration, and cardiac output were associated with rScO₂ by correlation analysis.Dopamine was superior to phenylephrine in maintaining cerebral oxygenation during OLV in thoracic surgery.     

Sodium butyrate prevents radiation-induced cognitive impairment by restoring pCREB/BDNF expression

Sodium butyrate is a histone deacetylase inhibitor that affects various types of brain damages. To investigate the effects of sodium butyrate on hippocampal dysfunction that occurs after whole-brain irradiation in animal models and the effect of sodium butyrate on radiation exposure-induced cognitive impairments,adult C57BL/6 mice were intraperitoneally treated with 0.6 g/kg sodium butyrate before exposure to 10 Gy cranial irradiation. Cognitive impairment in adult C57BL/6 mice was evaluated via an object recognition test 30 days after irradiation. We also detected the expression levels of neurogenic cell markers(doublecortin)and phosphorylated cAMP response element binding protein/brain-derived neurotrophic factor. Radiation-exposed mice had decreased cognitive function and hippocampal doublecortin and phosphorylated cAMP response element binding protein/brain-derived neurotrophic factor expression. Sodium butyrate pretreatment reversed these changes. These findings suggest that sodium butyrate can improve radiation-induced cognitive dysfunction through inhibiting the decrease in hippocampal phosphorylated cAMP response element binding protein/brain-derived neurotrophic factor expression. The study procedures were approved by the Institutional Animal Care and Use Committee of Korea Institute of Radiological Medical Sciences(approval No. KIRAMS16-0002) on December 30, 2016.     

Ruptured distal anterior choroidal artery aneurysm.

Ruptured aneurysms of the distal anterior choroidal artery (AchA) are extremely rare and management is dictated by clinical presentation. This report describes a rare patient with a distal AchA aneurysm and subarachnoid and intraventricular haemorrhage. A 60-year-old woman presented with a sudden onset of severe headache and vomiting. No aneurysms could be found on initial angiograms. A repeat angiogram performed 10 days after admission demonstrated an aneurysm in a branch of the cisternal segment of the left AchA without a definite neck. Surrounding vessels showed multifocal stricture and dilatation. Microsurgical clipping was not performed because the patient died suddenly due to pulmonary failure. The aetiology of the aneurysm in this case and surgical strategy are discussed.     

Outflow of aqueous humor following cyclodialysis or ciliochoroidal detachment in rabbit

Cyclodialysis and ciliochoroidal detachment were performed in three eyes of three rabbits and in three eyes of another three rabbits, respectively. After aspiration of the aqueous humor, 0.1 ml of 10% sodium fluorescein was injected intracamerally, and the eyeball was enucleated between 30 minutes and one hour after injection and prepared for fluorescence microscopy. Sodium fluorescein concentrations in the supraciliary space were much greater in the group with cyclodialysis or ciliochoroidal detachment than in the normal control group. These results suggest that (1) in the eye with cyclodialysis, the aqueous humor may freely gain access to the supraciliary space through the cleft between the anterior chamber and the supraciliary space and then be removed rapidly and (2) in the eye with ciliochoroidal detachment, the aqueous humor may pass through the uveoscleral outflow pathway.     

Mesogonadal shunts for extrahepatic portal vein thrombosis and variceal hemorrhage.

Extrahepatic portal vein thrombosis (EHPVT) may occur in children or adults and usually comes to clinical attention due to complications of portal hypertension such as variceal hemorrhage. A variety of standard surgical techniques exist to manage these patients, but when these fail surgical options are limited. We describe two novel portosystemic shunts that utilize the gonadal vein as an autologous conduit. Four patients were evaluated for EHPVT with variceal bleeding. None of the patients were candidates for a standard splenorenal shunt due to prior surgical procedures. The first patient underwent a left mesogonadal shunt and the remaining 3 patients underwent a right mesogonadal shunt. Postoperative ultrasound or computed tomography (CT) scan confirmed early patency of the shunt in each patient. There have been no further episodes of variceal hemorrhage with follow-up of 3.5 years in the child who underwent the left mesogonadal shunt, and 17, 19, and 20 months in the patients who underwent the right mesogonadal shunt. Three of the 4 shunts remain patent. One shunt thrombosis occurred in a patient homozygous for the Factor V Leiden mutation despite anticoagulation with coumadin. This is the first report of the successful use of the gonadal vein as an in situ conduit for constructing a portosystemic shunt. In conclusion, the right and left mesogonadal shunts may be useful as salvage operations for patients with EHPVT who have failed standard surgical shunt procedures.     

Controlled release of lidocaine hydrochloride from the surfactant-doped hybrid xerogels.

We investigate the controlled release of lidocaine hydrochloride from the doped silica-based xerogels. In the xerogel preparation, tetraethoxysilane (TEOS), methyltriethoxysilane (MTES), and propyltriethoxysilane (PTES) are used as precursors, and a nonionic surfactant Igepal CO 720 is used as a dopant. The experimental results suggest that the release of lidocaine hydrochloride can be easily controlled by partially substituting TEOS with the organosilanes, and/or by adding the dopant. Adding the organosilane precursors lowers the release of both the drug and the surfactant in the order of TEOS, MTES/TEOS, and PTES/TEOS xerogels. The release from the PTES/TEOS xerogels is much lower than that from the other xerogels. The release of lidocaine hydrochloride is obviously suppressed by the addition of Igepal CO 720, while the release of Igepal CO 720 is slightly promoted by the addition of the drug. The overall release process is found to be diffusion-controlled, and the release behaviors can be well explained by considering the effects of the textual properties of the xerogels and the interactions among the drug, the surfactant, and the xerogel matrices.