Influence of the washing program on the blood processing performance of a continuous autotransfusion device.

The continuous autotransfusion system has been widely used in surgical operations. It is known that if oil is added to blood, and this mixture is then processed by an autotransfusion device, the added oil is removed and reinfusion of fat is prevented by the device. However, there is no detailed report on the influence of the particular washing program selected on the levels of blood components including blood fat after continuous autotransfusion using such a system. Fresh bovine blood samples were processed by a commercial continuous autotransfusion device using the "emergency," "quality," and "high-quality" programs, applied in random order. Complete blood count (CBC) and serum chemistry were analyzed to determine how the blood processing performance of the device changes with the washing program applied. There was no significant difference in the CBC results obtained with the three washing programs. Although all of the blood lipids in the processed blood were decreased compared to those in the blood before processing, the levels of triglyceride, phospholipid, and total cholesterol after processing via the emergency program were significantly higher than those present after processing via the quality and high-quality programs. Although the continuous autotransfusion device provided consistent hematocrit quality, the levels of some blood lipid components showed significant differences among the washing programs.

Head rotation, flexion, and extension alter endotracheal tube position in adults and children.

PURPOSE: The purpose of this study was to evaluate the effect of head rotation in adults and children on endotracheal tube (ETT) position and to confirm previous results regarding the influence of head flexion and extension on ETT position. METHODS: After inducing anesthesia in 24 young adults and 22 children (aged 1-9 yr), ETTs were secured on the right corner of each of their mouths. Using a fiberoptic bronchoscope, the distance from the carina to the tip of the ETT was measured with each patient's head and neck placed in a neutral position, flexed, extended, rotated to the right, and rotated to the left. RESULTS: In all patients, flexing the head resulted in the ETT moving towards the carina, and extension resulted in the tube being displaced in the opposite direction. In adults, head rotation to the right resulted in withdrawal of the ETT in all but one patient; displacement was 0.8 +/- 0.5 cm (mean +/- SD) (P < 0.001). Head rotation to the left resulted in the endotracheal tube being displaced in an unpredictable direction by 0.1 +/- 0.6 cm. In children, head rotation to the right resulted in withdrawal of the ETT in all patients; displacement was 1.1 +/- 0.6 cm (P < 0.001). Head rotation to the left also resulted in partial withdrawal in all patients; displacement measured 0.6 +/- 0.4 cm (P < 0.001). CONCLUSIONS: In adult patients under general anesthesia, head rotation towards the side of ETT fixation resulted in partial withdrawal of the tube tip away from the carina, whereas head rotation to the opposite side displaced the tube in an unpredictable manner. In children, head rotation to either side resulted in withdrawal of the ETT away from the carina.

Synthesis of Ba2SiO4:Eu(2+) by a Hybrid Process and Its Luminescent Properties.

Ba2SiO4:Eu(2+) powders were prepared using a sol-gel-combustion (hybrid) process with tetraethyl orthosilicate (TEOS) and colloidal silica (C-SiO2) as Si sources. The effects of the silicon sources and preparation conditions on phase formation and luminescent properties were investigated. The B2S:Eu(2+) powders synthesized with TEOS were composed of the irregular particles, whereas C-SiO2 was more conducive to uniform particle distribution for the Ba2SiO4:Eu(2+) powders, leading to the enhancement of the emission intensity. The photoluminescence spectra of the synthesized powders exhibited broad excitation bands spanning 250 to 450 nm, and strong green-emission bands, whose intensities and positions were heavily dependent on the concentration of Eu(2+) and Sr(2+) substituted for Ba(2+) in Ba2SiO4.

Application of cerebral oximetry for a parturient with Takayasu's arteritis undergoing cesarean section -a case report-.

Takayasu's arteritis (TA) is a chronic inflammatory disease involving the aorta. Because TA sometimes involves cerebral arteries, anesthetic debates focus on cerebral monitoring. There is limited evidence as to which cerebral monitoring method is most adequate. Furthermore, there is insufficient evidence to determine which anesthetic technique is better for TA parturients. We experienced the case of a TA parturient who developed transient cerebral ischemia during cesarean section. The patient's TA involved her cerebral arteries, and her regional cerebral oxygen saturation (rSO2) was lower in the left side than in the right side. She complained of speech impairment, tinnitus, and stiffness of the posterior neck when the rSO2 levels dropped. The FloTrac/Vigileo™ system did not correlate with clinical symptoms, but the cerebral oximeter displayed the low oxygen saturation. We recommend the cerebral oximetry for cerebral monitoring in TA parturients who undergo cesarean sections, especially in hemodynamically unstable patients under regional anesthesia or unconscious patients under general anesthesia.

Comparison of the renal safety between carbon dioxide absorbent products under sevoflurane anesthesia: a pilot study.

BACKGROUND: The chemical reaction of carbon dioxide absorbent and sevoflurane is known to produce compound A. However, carbon dioxide absorbents are not controlled by the Food and Drug Administration, but are treated as industrial products in some nations. Moreover, carbon dioxide absorbents differ in their capacities to produce compound A, because their chemical compositions differ. In this study, we compared the renal safety between carbon dioxide absorbent products in patients under sevoflurane anesthesia. METHODS: Eighty patients with no preexisting renal disease undergoing elective gynecologic surgery were randomly assigned to receive sevoflurane or isoflurane anesthesia with one of four carbon dioxide absorbent products (Sodasorblime®, Sodalyme®, Sodasorb®, Spherasorb®) at the same fresh gas flow of 2 L/min. The renal safety was evaluated by changes of blood urea nitrogen (BUN), creatinine and urine N-acetyl-b-glucoseaminidase (NAG)-creatinine ratio at 24 hours and 72 hours after surgery from preoperative level. RESULTS: There was no significant difference in the renal safety indicators between carbon dioxide absorbents during sevoflurane anesthesia (P > 0.05). However, the BUN and urine NAG-creatinine ratios at 72 hours after surgery were higher in isoflurane anesthesia in some carbon dioxide absorbent groups (P = 0.03 and 0.04, respectively). CONCLUSIONS: We could not find significant differences of renal safety indicators with carbon dioxide absorbents. Although the adverse effect of carbon dioxide absorbents on renal function was not proved, consideration should be given to their contol by the regulation on their efficacy and safety because carbon dioxide absorbents can produce compound A.

Compartmental modeling and simplified quantification of [¹¹C]sertraline distribution in human brain.

Sertraline hydrochloride (Zoloft®, Pfizer) is an antidepressant drug of the selective serotonin reuptake inhibitor (SSRI). The aims of this study were evaluating its in vivo distribution and kinetic models in human brain. Also, this study was to determine optimal scan duration of dynamic positron emission tomography (PET) for accurate [¹¹C]sertraline kinetic parameters and the feasibility of semi-quantitative approach for assessing distribution volume ratio (DVR). [¹¹C]sertraline dynamic PET and magnetic resonance imaging (MRI) scans were performed in 5 healthy males. Blood sampling were collected for the input function. Tissue time-activity curves (TAC) were obtained in 7 brain regions using MRI. Goodness-of-fit for TAC using simple tissue compartment model (2C2P) and 3-compartment models with irreversible (3C3P) and reversible (3C4P) were compared. Total distribution volume (DV) for each region of interest (ROI) and DVR were calculated. Also, ratio between the standard uptake value (SUV) of each ROI and that of cerebellum (SUVr) was computed and correlated with the DVR. Akaike information criteria analysis showed that the 2C2P was the most suitable model. Average values of K1 (mL/min/g) and k2 (1/min) were 0.54 and 0.012 in putamen. PET scan time longer than 50 min was required for the accurate estimation of DV. SUVr in 50-90 min was well correlated with DVR.

Suction conditions for minimizing the production of free hemoglobin during blood salvage using an autotransfusion apparatus.

BACKGROUND: Three kinds of conditions should be considered to reduce free hemoglobin production using an autologous cell salvage device. They are the negative suction pressure, the size of suction tip, and the air contact during suction. We want to examine which condition is the most important factor to produce free hemoglobin. METHODS: One pack of red blood cell and one pack of fresh frozen plasma with the same blood type were mixed. They were aspirated based on the two suction pressure (-150 mmHg or -300 mmHg), three sizes of suction tips, and the two conditions of air contact, in which the suction tip was located in the surface of blood or in the middle of the blood. Seven ml sized EDTA tube was used to collect 5 ml blood. All the procedure repeated ten times. Free hemoglobin, total hemoglobin, and hematocrit were measured. Hemolysis ratio was calculated with following formula. Hemolysis ratio = (new free hemoglobin production) × (100-hematocrit) / (total hemoglobin). RESULTS: Free hemoglobin production and hemolysis ratio were increased when the suction tip was positioned in the surface than when it was in the middle of the blood. The pressure of negative suction and three kinds of the suction tips did not influence the production of free hemoglobin nor the hemolysis ratio. CONCLUSIONS: The air contact is the most important factor to reduce hemolysis using autologous cell salvage device. Suction pressure or suction tip diameter have little influence to produce hemolysis.

Effect of airway pressure on lumbar epidural pressure during positive pressure ventilation.

BACKGROUND: The purpose of this study was to measure lumbar epidural pressure (EP) during the insertion of a Tuohy needle under general anesthesia and to evaluate the influence of airway pressure on EP. METHODS: Lumbar EP was measured directly through a Tuohy needle during intermittent positive pressure ventilation in fifteen patients. Mean and peak EP were recorded after peak inspiratory pressures (PIP) of 0, 15, and 25 cmH(2)O. RESULTS: All measured lumbar EPs were positive, with the pressure increasing during inspiration and decreasing during expiration. Median EP was 6.0 mmHg (interquartile range, 4.0-8.0) at 0 cmH(2)O of PIP, 6.5 mmHg (4.5-8.5) at 15 cmH(2)O, and 8.5 mmHg (6.0-10.5) at 25 cmH(2)O, increasing significantly at 15 cm H(2)O PIP, and further increasing at 25 cmH(2)O (P < 0.001). CONCLUSIONS: We demonstrate the influence of increased airway pressure on lumbar EP measured directly through a Tuohy needle. Lumbar EPs were positive, and increasing PIP levels significantly increased lumbar EP.

The neurological safety of epidural parecoxib in rats.

Epidural injection of cyclooxygenase-2 inhibitors has been suggested as a useful therapeutic modality in pain management in animal studies and clinical settings. Direct epidural administration of parecoxib, a highly selective cyclooxygenase-2 inhibitor, may have advantages over its parenteral administration regarding required dose, side effects, and efficacy. However, no animal studies have been performed to investigate the possible neurotoxicity of epidurally injected parecoxib. Therefore, the present study was performed to assess the neurotoxicity of epidurally injected parecoxib in rats. Rats (n=45) were randomly divided into three groups: normal saline group (group N, n=15), ethanol group (group E, n=15), and parecoxib group (group P, n=15). 0.3 mL of epidural parecoxib (6 mg) and the same volume of epidural ethanol or normal saline were injected into the epidural space. Neurologic assessment was performed 3, 7 and 21 days after the injection by pinch toe testing. Histologic changes were evaluated for vacuolation of the dorsal funiculus, chromatolytic changes of the motor neurons, neuritis, and meningeal inflammation. All rats in groups N and P showed normal response to pinch-toe testing and had a normal gait at each observation point. Histological examination showed no evidence suggestive of neuronal body or axonal lesions, gliosis, or myelin sheet damage in group N or P at any time. However, all rats in group E showed sensory-motor dysfunction, behavioral change, or histopathological abnormalities. No neurotoxicity on the spinal cord or abnormalities in sensorimotor function or behavior was noted in rats that received epidural parecoxib.

Local anesthetics inhibit tissue factor expression in activated monocytes via inhibition of tissue factor mRNA synthesis.

Local anesthetics have been reported to have anticoagulant properties, but the mechanisms responsible for this action are poorly understood. Here, we evaluated the in vitro effects of 3 local anesthetics--lidocaine, ropivacaine, and bupivacaine--on the tissue factor expression by monocytes. Monocytes from peripheral blood were stimulated with lipopolysaccharide (LPS) in the presence or absence of local anesthetics. All 3 local anesthetics inhibited the expression of tissue factor antigen and tissue factor activity in LPS-stimulated monocytes in a dose- and time-dependent manner and reduced tissue factor messenger RNA (mRNA) expression in endothelial cells and a monocytic cell line. None of the 3 drugs induced apoptosis or affected the viability of monocytes. Our findings that local anesthetics inhibited the tissue factor induction in activated monocytes by inhibiting tissue factor mRNA level may demonstrate the feasibility of using local anesthetics in hypercoagulable and inflammatory conditions.

Growth suppression of four cancer cells by hyperbaric nitrous oxide and methotrexate.

BACKGROUND: Nitrous oxide concentration is easily controlled by respiratory ventilation. It suppresses bone marrow via the inhibition of thymidylate synthesis. The aim of this work was to determine the optimal pressure and exposure duration of nitrous oxide, as well as methotrexate concentration that maximizes the suppression of 4 cancer cells: CCRF-CEM, K562, A549 and MDA-MB-231. METHODS: Each cancer cell was cultured in a hyperbaric chamber at 1, 2 and 3 atmosphere of 74% nitrous oxide for 24, 48, and 72 hours at 0, 0.3, 0.7, 1, 2, 5 and 10 microM methotrexate (MTX), respectively. The results were expressed in the ratio of the number of cancer cells cultured under specific conditions (S cells) to that under normal conditions (N cells). RESULTS: The S/N ratio of CCRF-CEM cells was 87.4% in 24-hour culture, 95.0% in 48-hour culture and 115.9% in 72-hour culture (P < 0.05). The S/N ratio of K562 cells was 103.6% at 1 atm, 102.4% at 2 atm and 115.6% at 3 atm (P < 0.05). The S/N ratio of A549 cells was 94.3% at 1 atm, 94.1% at 2 atm, 99.3% at 3 atm, 96.2% in 24-hour culture, 99.2% in 48-hour culture and 99.3% in 72-hour culture (P > 0.05). However, the S/N ratio of MDA-MB 231 cells was 66.9% in 24-hour culture, 83.1% in 48 hour culture and 87.8% in 72-hour culture (P < 0.05). CONCLUSIONS: Only the growth of the MDA-MB-231 cells was significantly reduced after a longer exposure time to nitrous oxide, but those of the other cells were not.

A survey on informed consent process for epidural analgesia in labor pain in Korea.

BACKGROUND: There is a legal obligation to explain the procedure and use of epidural analgesia in labor primarily due to the possibility of potential risks and associated complications. The present study details on the survey carried out to ascertain the current status of obtaining informed consent (IC) for explaining the epidural analgesia in labor. METHODS: The present study is based on a survey through a telephone questionnaire that covered all the hospitals in Korea where the anesthesiologists' belonged to and are registered with Korean Society of Anesthesiologists. The questionnaire included questions pertaining to administration of epidural analgesia to a parturient, information on different steps of obtaining an IC, whether patient status was evaluated, when the consent was obtained, and the reasons behind, if the consent had not being given. RESULTS: A total of 1,434 respondents took part in the survey, with a response rate of 97% (1,434/1,467). One hundred seventy-four hospitals had conducted epidural analgesia on the parturient. The overall rate of obtaining IC for epidural analgesia during labor was 85%, of which only 13% was conducted by anesthesiologists. The rate of evaluating preoperative patient status was 74%, of which 45% was conducted by anesthesiologists. Almost all of the consent was obtained prior to the procedure. CONCLUSIONS: The rate of obtaining IC for epidural analgesia in labor is relatively high (85%) in Korea. However, it is necessary to discuss the content of the consent and the procedure followed for obtaining IC during the rapid progress of labor.

Bilateral femoral neuropathy after vaginal delivery: A case report.

Epidural analgesia is frequently used for the management of labor pain in parturients. The neurologic complications of epidural analgesia are rare, but they are catastrophic when they occur. We report here on a case of bilateral femoral neuropathy in a vaginal delivery patient with epidural analgesia. The patient complained of weakness of both thighs and numbness around both knees. Neurologic examination and electromyographic study revealed that they occurred due to the delivery itself. The patient had not fully recovered at eight weeks after delivery. The declining incidence of postpartum femoral neuropathy may reflect a reduced duration of labor in accordance with modern obstetric practice, and particularly the more frequent use of Caesarean delivery. The exact etiology of postpartum femoral neuropathy is unknown, and the possible factors are direct compression of nerves that are proximal within the pelvis by either the fetal head or birthing instruments, or this malady is the result of pressure induced ischemia at the level of the inguinal ligament when the pregnant woman is in the lithotomy position.