bluuebunny/crossref_metadata_2025_split huggingface dataset:
Single-needle Celiac Plexus Block
Authors: De Cicco Marcello , Matovic Mira , Balestreri Luca , Fracasso Augusto , Morassut Sandro , Testa Vinicio 
Published: November 2003

Background
The "single-needle" celiac plexus block is becoming a popular technique. Despite different approaches and methods used to place the needle, the success of the block depends on adequate spread of the injectate in the celiac area. In the present retrospective study, the influence of needle tip position in relation to the celiac artery on injectate spread was evaluated.

Methods
Among 138 cancer patients subjected, via an anterior approach, to computed tomography (CT)-guided single-needle neurolytic celiac plexus block, a radiologist, blinded to the aim of the study, retrospectively selected 53 cases with normal anatomy of the celiac area as judged by CT. The decision was based on images obtained before the block. Patients were then classified into either group A (29 patients), in whom the needle tip was caudad to the celiac artery, and group B (24 patients), in whom it was cephalad. To evaluate CT patterns of neurolytic (mixed with contrast) spread, the celiac area was divided on the frontal plane into four quadrants: upper right and left and lower right and left, as related to the celiac artery. Patient assessments by visual analog scale were reviewed to evaluate the degree of pain relief. Pain relief 30 days after block was judged as long-lasting. The patterns of contrast spread in relation to the needle position and pain relief according to the number of quadrants with contrast were analyzed.

Results
The percentage of cases with four quadrants with contrast was higher when the needle tip was cephalad (58%, group B) than when it was caudad (14%, group A) to the celiac artery (P < 0.01). The percentage of patients with four and three quadrants with contrast was also higher in group B at 79% than in group A at 38% (P < 0.01). A significant difference in long-lasting pain relief was observed between patients with four quadrants with contrast (18 of 18, 100%; 95% confidence interval [CI], 81-100%) and patients with three quadrants with contrast (5 of 12, 42%; 95% CI, 15-72%) (P < 0.01). No patients showing two or one quadrant with contrast had long-lasting pain relief.

Conclusions
These findings suggest that, when the celiac area is free from anatomic distortions, and the single-needle neurolytic celiac plexus block technique is used, the needle tip should be positioned cephalad to the celiac artery to achieve a wider neurolytic spread. It also appears that only a complete (four quadrants) neurolytic spread in the celiac area can guarantee long-lasting analgesia.
Ketamine Decreases Intracranial Pressure and Electroencephalographic Activity in Traumatic Brain Injury Patients during Propofol Sedation
Authors: Albanese Jacques , Arnaud Sophie , Rey Marc , Thomachot Laurent , Alliez Bernard , Martin Claude 
Published: November 2003

Background
The potential adverse effects of ketamine in neurosurgical anesthesia have been well established and involve increased intracranial pressure (ICP) and cerebral blood flow. However, reexamination of ketamine is warranted because data regarding the effects of ketamine on cerebral hemodynamics are conflicting.

Methods
Eight patients with traumatic brain injury were studied. In all patients, ICP monitoring was instituted before the study. Control of ICP (less than 25 mmHg), hemodynamic values, and blood gas tension (partial pressure of carbon dioxide in arterial blood between 35-38 mmHg) was obtained with propofol infusion (3 mg x kg(-1) x h(-1)) and mechanical ventilation. The effects of three doses of ketamine, 1.5, 3, and 5 mg/kg, respectively, on ICP, cerebral perfusion pressure, jugular vein bulb oxygen saturation, middle cerebral artery blood flow velocity, and electric activity of the brain (EEG) were measured. The three doses were administered intravenously at 6-h intervals over 30 s through a central venous line. Systemic and cerebral hemodynamics and end-tidal carbon dioxide were continuously monitored and recorded at 1-min intervals throughout the 30-min study periods.

Results
Ketamine, in all three doses studied (1.5, 3, and 5 mg/kg) was associated with a significant decrease in ICP (mean +/- SD: 2 +/- 0.5 mmHg [P < 0.05], 4 +/- 1 mmHg [P < 0.05], and 5 +/- 2 mmHg [P < 0.05]) among the study patients regardless of the ketamine dose used. There were no significant differences in cerebral perfusion pressure, jugular vein bulb oxygen saturation, and middle cerebral artery blood flow velocity. Ketamine induced a low-amplitude fast-activity electroencephalogram, with marked depression, such as burst suppression.

Conclusions
These results suggest that ketamine may not adversely alter cerebral hemodynamics of mechanically ventilated head-trauma patients sedated with propofol. These encouraging results should be confirmed in larger groups of similar patients.
Aprotinin Decreases Blood Loss and Homologous Transfusions in Patients Undergoing Major Orthopedic Surgery
Authors: Capdevila Xavier , Calvet Yves , Biboulet Philippe , Biron Christine , Rubenovitch Josh , d'Athis Francoise 
Published: November 2003

Background
Major orthopedic surgery can be associated with dramatic blood loss, thereby requiring high-volume homologous transfusions in patients unable to benefit from blood salvage techniques. The effect of aprotinin on blood loss and transfusion requirements during orthopedic surgery for either the resection of malignancies of the removal of infected hardware was prospectively studied.

Methods
Twenty-three patients scheduled for orthopedic surgery of the hip, femur, or pelvis for sepsis or malignant tumors, all under general anesthesia, were randomly allocated to receive during operation, in a blinded manner, either aprotinin administered as a bolus of 1.106 kallikrein inactivation units (KIU) followed by an infusion of 5 x 10(5) KIU/h, or the equivalent volume of saline. The anesthesia and perioperative management, as well as the designated transfusion criteria, were standardized. The total blood loss of each patient was evaluated using intraoperative suction losses, sponge weights, and postoperative volumetric drainage. Homologous transfusion requirements were noted. Hemoglobin and hematocrit measures, as well as coagulation and fibrinolytic pathway explorations, were performed before and after surgery. Deep venous thrombosis prophylaxis was applied, and the incidence of this complication was assessed.

Results
Twelve patients received aprotinin. Aprotinin reduced the total blood loss from a median of 5,305 ml (range, 3,000-9,770 ml) to a median of 1,783 ml (range, 1,140-4,955 ml; P < 0.05). A blood loss reduction of 56% during surgery and 68% on discharge from the postanesthesia care unit was observed. Seven units (range, 4-16) of packed erythrocytes were transfused per patient in the placebo group, and 3 (range, 2-5) were transfused in the aprotinin group (P < 0.05). In the aprotinin group, platelet counts were higher, and postoperative prothrombin times and D. Dimer values were lower. The activated partial thromboplastin time values showed no significant difference between the two groups. No side effects were observed in the aprotinin group. A deep venous thrombosis developed in one patient in the placebo group.

Conclusion
Aprotinin treatment during major orthopedic surgery significantly reduces both blood loss and consequent homologous blood transfusion requirements.
Psychedelic Effects of Ketamine in Healthy Volunteers
Authors: Bowdle Andrew T. , Radant Allen D. , Cowley Deborah S. , Kharasch Evan D. , Strassman Rick J. , Roy-Byrne Peter P. 
Published: November 2003

Background
Ketamine has been associated with a unique spectrum of subjective "psychedelic" effects in patients emerging from anesthesia. This study quantified these effects of ketamine and related them to steady-state plasma concentrations.

Methods
Ketamine or saline was administered in a single-blinded crossover protocol to 10 psychiatrically healthy volunteers using computer-assisted continuous infusion. A stepwise series of target plasma concentrations, 0, 50, 100, 150, and 200 ng/ml were maintained for 30 min each. After 20 min at each step, the volunteers completed a visual analog (VAS) rating of 13 symptom scales. Peripheral venous plasma ketamine concentrations were determined after 28 min at each step. One hour after discontinuation of the infusion, a psychological inventory, the hallucinogen rating scale, was completed.

Results
The relation of mean ketamine plasma concentrations to the target concentrations was highly linear, with a correlation coefficient of R = 0.997 (P = 0.0027). Ketamine produced dose-related psychedelic effects. The relation between steady-state ketamine plasma concentration and VAS scores was highly linear for all VAS items, with linear regression coefficients ranging from R = 0.93 to 0.99 (P < 0.024 to P < 0.0005). Hallucinogen rating scale scores were similar to those found in a previous study with psychedelic doses of N,N-dimethyltryptamine, an illicit LSD-25-like drug.

Conclusions
Subanesthetic doses of ketamine produce psychedelic effects in healthy volunteers. The relation between steady-state venous plasma ketamine concentrations and effects is highly linear between 50 and 200 ng/ml.
31Phosphorus Magnetic Resonance Spectroscopy Characterization of Muscular Metabolic Anomalies in Patients with Malignant Hyperthermia
Authors: Bendahan David , Kozak-Ribbens Genevieve , Rodet Laurence , Confort-Gouny Sylviane , Cozzone Patrick J. 
Published: November 2003

Background
Metabolic anomalies are known in skeletal muscles of patients with malignant hyperthermia (MH).

Methods
The authors used 31-phosphorus (31P) magnetic resonance spectroscopy (MRS) to compare metabolic changes of the finger flexor muscles recorded throughout two rest-exercise-recovery protocols (each including aerobic or ischemic exercise) in 26 healthy persons and in 13 MH-susceptible (MHS) persons who were unequivocally diagnosed by in vitro halothane-caffeine contracture tests on muscle biopsies.

Results
No abnormality was observed at rest and during recovery periods. A larger phosphocreatine decrease associated with an early drop of pH was noted during the first minute of both exercise periods for MHS patients compared with controls. The early pH decrease indicated a disorder affecting glycolytic activation, probably reflecting defects of Ca2+ cycling, and provided a sensitivity of 77% for MHS diagnosis. A diagnostic strategy based on the retrospective analysis of 19 selected MR parameters was developed. An MRS score, corresponding to the number of abnormal values among the 19 parameters, was calculated and provided sensitivity and specificity rates of 100%; that is, no false-positive or false-negative results were found. A prospective analysis of 10 new participants further confirmed these findings.

Conclusions
These results (1) further confirm that MH is associated with the preexistence of latent muscular disorders; (2) enhance the potential diagnostic capacity of MRS, although it should be tested prospectively on a larger group of participants; and (3) allows the characterization of several abnormal metabolic profiles, in persons with MHS, reflecting the recently described polymorphism of MH.
Use of a Vital Capacity Maneuver to Prevent Atelectasis after Cardiopulmonary Bypass
Authors: Magnusson Lennart , Zemgulis Vitas , Tenling Arne , Wernlund Johan , Tyden Hans , Thelin Stefan , Hedenstierna Goran 
Published: November 2003

Background
Respiratory failure secondary to cardiopulmonary bypass (CPB) remains a major complication after cardiac surgery. The authors previously found that the increase in intrapulmonary shunt was well correlated with the amount of atelectasis. They tested the hypothesis that post-CPB atelectasis can be prevented by a vital capacity maneuver (VCM) performed before termination of the bypass.

Methods
Eighteen pigs received standard hypothermic CPB (no ventilation during bypass). The VCM was performed in two groups and consisted of inflating the lungs during 15 s to 40 cmH2O at the end of the bypass. In one group, the inspired oxygen fraction (FIO2) was then increased to 1.0. In the second group, the FIO2 was left at 0.4. In the third group, no VCM was performed (control group). Ventilation-perfusion distribution was measured with the inert gas technique and atelectasis by computed tomographic scanning.

Results
Intrapulmonary shunt increased after bypass in the control group (from 4.9 +/- 4% to 20.8 +/- 11.7%; P < 0.05) and was also increased in the vital capacity group ventilated with 100% oxygen (from 2.2 +/- 1.3% to 6.9 +/- 2.9%; P < 0.01) but was unaffected in the vital capacity group ventilated with 40% oxygen. The control pigs showed extensive atelectasis (21.3 +/- 15.8% of total lung area), which was significantly larger (P < 0.01) than the proportion of atelectasis found in the two vital capacity groups (5.7 +/- 5.7% for the vital capacity group ventilated with 100% oxygen and 2.3 +/- 2.1% for the vital capacity group ventilated with 40% oxygen.

Conclusion
In this pig model, postcardiopulmonary bypass atelectasis was effectively prevented by a VCM.
Characterization of the Effects of Gabapentin and 3-Isobutyl-γ-Aminobutyric Acid on Substance P-induced Thermal Hyperalgesia
Authors: Partridge Brett J. , Chaplan Sandra R. , Sakamoto Eiji , Yaksh Tony L. 
Published: November 2003

Background
The authors sought to characterize the pharmacologic characteristic and site of action of gabapentin (Neurontin) in a model of thermal hyperalgesia induced by intrathecal substance P administration.

Methods
Rats were prepared with long-term lumbar intrathecal catheters. Hind paw withdrawal latency was determined using a radiant heat stimulus focused through a glass surface onto the plantar surface of the paw.

Results
Within 5 min after intrathecal injection of substance P (30 nmol), hind paw withdrawal latency fell from 11 to 8 s. Gabapentin given intrathecally or intraperitoneally produced dose-dependent reversal of the thermal hyperalgesia, with complete reversal (ED100) occurring at 163 microg for intrathecal and 185 mg/kg for intraperitoneal administration. S(+)-3-isobutyl-gamma aminobutyric acid, but not R(-)-3-isobutyl-gamma aminobutyric acid, also produced dose-dependent reversal of the intrathecal substance P-induced thermal hyperalgesia (intrathecal ED100, 65 microg and intraperitonal ED100, 31 mg/kg). The effects of intraperitoneally administered gabapentin and 3-isobutyl-gamma aminobutyric acid were reversed by intrathecal pretreatment with D-serine (100 microg) but not by L-serine. All effects were observed at doses that had little effect on motor function or spontaneous activity. Intrathecal N-methyl-D-aspartate (2 nmol) induced thermal hyperalgesia, which was blocked by gabapentin (100 mg/kg intraperitoneally) and S(+)-3-isobutyl-gamma aminobutyric acid (30 mg/kg intraperitoneally).

Conclusions
The structure-activity relationship and the stereospecificity noted after intrathecal delivery suggest that gabapentin and S(+)-3-isobutyl-gamma aminobutyric acid act at a common spinal locus to modulate selectively a facilitated state of nociceptive processing.
Improved Contractility and Coronary Flow in Isolated Hearts after 1-Day Hypothermic Preservation with Isoflurane Is Not Dependent on KATPChannel Activation
Authors: Stowe David F. , Fujita Satoshi , Bosnjak Zeljko J. 
Published: November 2003

Background
Isoflurane protects against reperfusion injury in isolated hearts when given before, during, and initially after hypoxia or ischemia and aids in preconditioning hearts if given before ischemia. The aims of the current study were to determine if isoflurane is cardioprotective during 1-day, severe hypothermic perfusion and if a mechanism of protection is K(ATP) channel activation.

Methods
Guinea pig hearts (n = 60) were isolated, perfused with Kreb's solution initially at 37 degrees C, and assigned to either a nontreated warm, time control group or one of five cold-treated groups: drug-free cold control, 1.3% isoflurane, 1.3% isoflurane plus glibenclamide (4 microM), 2.6% isoflurane, or 2.6% isoflurane plus glibenclamide. Isoflurane and glibenclamide were given 20 min before hypothermia, during low-flow hypothermia (3.8 degrees C) for 22 h, and for 30 min after rewarming to 37 degrees C. Heart rate, left ventricular pressure, %O2 extraction, and coronary flow were measured continuously, and responses to epinephrine, adenosine, 5-hydroxytryptamine, and nitroprusside were examined before and after hypothermia.

Results
Each group had similar initial left ventricular pressures, coronary flows, and responses to adenosine, 5-hydroxytryptamine, and nitroprusside. Before hypothermia, isoflurane with or without glibenclamide increased coronary flow while decreasing left ventricular pressure and %O2 extraction. After hypothermia, left ventricular pressure and coronary flow were reduced in all cold groups but least reduced in isoflurane-treated groups. During normothermic perfusion after isoflurane and glibenclamide, left ventricular pressure, coronary flow, %O2 extraction, and flow responses to adenosine, 5-hydroxytryptamine, and nitroprusside were similarly improved in isoflurane and isoflurane-plus-glibenclamide groups over the cold control group but not to levels observed in the warm-time control group.

Conclusion
Isoflurane, like halothane, given before, during, and initially after hypothermia markedly improved but did not restore cardiac perfusion and function. Protective effects of isoflurane were not concentration dependent and not inhibited by the K(ATP) channel blocker glibenclamide. Volatile anesthetics have novel cardioprotective effects when given during long-term severe hypothermia.
Recovery of Storage and Emptying Functions of the Urinary Bladder after Spinal Anesthesia with Lidocaine and with Bupivacaine in Men
Authors: Kamphuis Ed T. , Ionescu Trian I. , Kuipers Peter W. G. , de Gier Jos , van Venrooij Ger E. P. M. , Boon Tom A. 
Published: November 2003

Background
The aim of this study was to evaluate and compare the effects of spinal anesthesia with lidocaine and with bupivacaine on urinary bladder function in healthy men who were scheduled for minor orthopaedic surgical procedures.

Methods
Twenty men were randomly allocated to receive either bupivacaine or lidocaine. Before spinal anesthesia, filling cystometry was performed with the patient in the supine position and a pressure flow study was done with the patient in the standing position. After operation, cystometric measurements were continued until the patient could void urine spontaneously. The levels of analgesia and of motor blockade were recorded.

Results
The urge to void disappeared immediately after injection of the local anesthetics. There was no difference in the duration of lower extremity motor blockade between bupivacaine and lidocaine. Detrusor blockade lasted significantly longer in the bupivacaine group (means +/- SD, 460 +/- 60 min) than in the lidocaine group (235 +/- 30 min). Total fluid intake and urine volume accumulated during the detrusor blockade were significantly higher in the bupivacaine group than in the lidocaine group. In the bupivacaine group, the total volume of accumulated urine (875 +/- 385 ml) was also significantly higher than cystometric bladder capacity (505 +/- 120 ml) with the risk of over distension of the bladder. Spontaneous voiding of urine did not occur until segmental sensory analgesia had regressed to the third sacral segment.

Conclusions
Spinal anesthesia with lidocaine and with bupivacaine causes a clinically significant disturbance of bladder function due to interruption of the micturition reflex. The urge to void disappears quickly and bladder function remains impaired until the block has regressed to the third sacral segment in all patients. With long-acting local anesthetics, the volume of accumulated urine may exceed the cystometric bladder capacity. With respect to recovery of urinary bladder function, the use of short-acting local anesthetics for spinal anesthesia seems to be preferable.
Variability in Transfusion Practice for Coronary Artery Bypass Surgery Persists Despite National Consensus Guidelines
Authors: Stover Price E. , Siegel Lawrence C. , Parks Reg , Levin Jack , Body Simon C. , Maddi Rosemarie , D'Ambra Michael N. , Mangano Dennis T. , Spiess Bruce D. 
Published: November 2003

Background
An estimated 20% of allogeneic blood transfusions in the United States are associated with cardiac surgery. National consensus guidelines for allogeneic transfusion associated with coronary artery bypass graft (CABG) surgery have existed since the mid- to late 1980s. The appropriateness and uniformity of institutional transfusion practice was questioned in 1991. An assessment of current transfusion practice patterns was warranted.

Methods
The Multicenter Study of Perioperative Ischemia database consists of comprehensive information on the course of surgery in 2,417 randomly selected patients undergoing CABG surgery at 24 institutions. A subset of 713 patients expected to be at low risk for transfusion was examined. Allogeneic transfusion was evaluated across institutions. Institution as an independent risk factor for allogeneic transfusion was determined in a multivariable model.

Results
Significant variability in institutional transfusion practice was observed for allogeneic packed red blood cells (PRBCs) (27-92% of patients transfused) and hemostatic blood components (platelets, 0-36%; fresh frozen plasma, 0-36%; cryoprecipitate, 0-17% of patients transfused). For patients at institutions with liberal rather than conservative transfusion practice, the odds ratio for transfusion of PRBCs was 6.5 (95% confidence interval [CI], 3.8-10.8) and for hemostatic blood components it was 2 (95% CI, 1.2-3.4). Institution was an independent determinant of transfusion risk associated with CABG surgery.

Conclusions
Institutions continue to vary significantly in their transfusion practices for CABG surgery. A more rational and conservative approach to transfusion practice at the institutional level is warranted.
In Vivo and In Vitro Studies of the Inhibitory Effect of Propofol on Human Platelet Aggregation
Authors: Aoki Hiroshi , Mizobe Toshiki , Nozuchi Shinji , Hiramatsu Noriko 
Published: November 2003

Background
The inhibitory effects of propofol on platelet aggregation are controversial because the fat emulsion used as the solvent for propofol may affect platelet function. The effects of propofol on platelet intracellular calcium ion concentration and on aggregation were investigated.

Methods
Platelet aggregation was measured in 10 patients who received an intravenous infusion of propofol. Intralipos, the propofol solvent, was infused in 10 healthy volunteers and platelet aggregation were measured. The in vitro effects of propofol and Intralipos on platelets were also investigated. The inhibitory effects of various concentrations of propofol were studied. The effects of propofol on the changes in intracellular calcium level using a fluorescent dye, fura-2, were also observed. Template bleeding time was measured to determine the effect of propofol in clinical use.

Results
Platelet aggregation was significantly inhibited by infusion of propofol, although bleeding time was not prolonged. Intralipos did not inhibit platelets either in vivo or in vitro. Propofol significantly inhibited platelet aggregation in vitro and at 5.81 +/- 2.73 microg/ml but not at 2.08 +/- 1.14 microg/ml. The increase of intracellular calcium concentration was inhibited both in influx and discharge of calcium.

Conclusions
Propofol inhibited platelet aggregation both in vivo and in vitro. Inhibition of platelet aggregation appeared to be caused by propofol itself and not by the fat emulsion. This inhibitory effect was also supported by the suppressed influx and discharge of calcium. No change in the bleeding time suggests that this inhibitory effect does not impair hemostasis clinically.