bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aminoguanidine does not influence tissue extravasation of albumin in endotoxaemic rats
Authors: Metcalf K. , Lisander B. 
Published: March 2003

Background: It is generally maintained that protein and fluid are lost from the circulation under septic conditions. The role played by an increased production of nitric oxide, by the inducible nitric oxide synthase (iNOS), in this process is unclear.Methods: Chloralose anaesthetised male Wistar rats received E. coli lipopolysaccharide (LPS), 3 mg kg−1 i.v., and were studied for 5 h. Mean arterial pressure (MAP) and heart rate (HR) were monitored and haematocrit (Hct) was determined intermittently. Tissue plasma volume and tissue clearances of radiolabelled albumin over the last 2 h of the experiment were determined by a double‐isotope method. In 8 rats, 2 h after LPS, aminoguanidine, an iNOS selective blocker, was given i.v. at a dose of 5 mg kg−1. This was followed by a continuous infusion for the duration of the experiment; altogether 20 mg kg−1 was administered. In the control group (n=8), a corresponding volume of saline was infused.Results: Aminoguanidine did not significantly influence Hct, MAP and HR, as evidenced by inter‐group comparisons (Mann‐Whitney test). Tissue plasma clearances of albumin and tissue plasma volume were similar in both groups.Conclusion: Aminoguanidine at 20 mg kg−1 did not reverse the haemodynamic changes induced by LPS. Neither did the drug affect the tissue plasma clearance of albumin or the tissue plasma volume.
Effects of isoflurane on nitric oxide metabolism and oxidant status of guinea pig myocardium
Authors: Durak İ. , Kavutcu M. , Kaçmaz M. , Avci A. , Horasanli E. , Dikmen B. , Çimen M. Y. B. , Öztürk H. S. 
Published: March 2003

Background: Volatile anesthetics (VAs) have been shown to enhance myocardial recovery during reperfusion, the mechanism of which has not been clarified yet. It has been supposed that this effect of VAs may appear through antioxidative mechanisms.Methods: Thirty guinea pigs were used in the study. There were three groups with 10 animals in each: I – control, II – isoflurane+oxygen and III – oxygen. Isoflurane (2.0% v/v) and oxygen (100%) mixture was given to the animals via a face mask in the isoflurane+oxygen group at the rate of 2 l per min for 30 min a day for three consecutive days. In the oxygen group, oxygen alone (100%) was given under the same conditions as in the isoflurane+oxygen group. At the end of the experiments, the animals were killed and their hearts were removed. In the heart tissues, nitric oxide synthase (NOS) activity, nitric oxide (NO) pool (NO•+NO2−) and malondialdehyde (MDA) levels were measured.Results: NOS activity was found to be higher and the NO pool lower in the isoflurane+oxygen group compared with those of control and oxygen groups. In the oxygen group, MDA level was found to be higher compared to the other groups. There was, however, no significant difference between MDA levels of the control and isoflurane+oxygen groups.Conclusion: Our results suggest that isoflurane prevents peroxidation reactions in heart tissue, possibly by scavenging toxic oxygen radicals produced under hyperoxygenation conditions as occurs with general anesthesia.
Descending aortic blood flow and cardiac output: A clinical and experimental study of continuous oesophageal echo‐Doppler flowmetry
Authors: Odenstedt H. , Åneman A. , Oi Y. , Svensson M. , Stenqvist O. , Lundin S. 
Published: March 2003

Background: Several studies have demonstrated that perioperative optimisation of oxygen delivery and haemodynamics can reduce mortality and morbidity for high‐risk surgical patients. To optimise cardiac output, reliable, continuous and “less invasive” methods for measuring cardiac output are urgently needed.Methods: Eight landrace pigs were studied during experimental repeated cardiac tamponade and 14 patients during liver transplantation. Aortic blood flow was measured by using transoesophageal echo‐Doppler technique. A total of 91 paired measurements of aortic blood flow and cardiac output with different techniques were performed in the pigs and 124 paired measurements in the patients.Results: Transoesophageal echo‐Doppler did provide continuous real‐time monitoring of the rapid and dramatic haemodynamic changes occurring during cardiac tamponade and during liver transplantation, while only intermittent information was obtained from the bolus thermodilution technique. Changes in haemodynamics were more difficult to detect with the “continual” cardiac output thermodilution technique. Changes in aortic blood flow closely followed changes in cardiac output determined by the bolus thermodilution technique both in pigs (r=0.89) and in patients (r=0.80). In patients, aortic blood flow constituted about 70% of cardiac output determined by the bolus thermodilution technique.Conclusions: A combined echo‐Doppler technique can be valuable for continuous monitoring of haemodynamic changes in the perioperative setting, and changes in aortic blood flow agree well with corresponding changes in cardiac output intermittently obtained by thermodilution cardiac output measurements. With the combined echo‐Doppler technique a proper position of the Doppler beam is greatly facilitated by the M‐mode echo visualisation of the aortic wall and aortic cross‐sectional area is continuously measured.
THIS ARTICLE HAS BEEN RETRACTED: Point‐of‐care (POC) testing of lactate in the intensive care patient
Authors: Boldt J. , Kumle B. , Suttner S. , Haisch G. 
Published: March 2003

Background: Point‐of‐care (POC) monitoring may facilitate diagnostic and therapeutic interventions in the critically ill. In a prospective study reliability and costs of two POC lactate testing devices were compared to the central laboratory lactate monitoring method.Methods: From arterial whole blood and capillary blood samples of 40 intensive care unit (ICU) patients lactate concentrations were measured using either a battery‐powered hand‐held lactate analyser (Accusport®) or a bench‐top blood gas analyser (Chiron 865 series) and compared with lactate measured by the hospital’s central laboratory (‘reference’ method). Measurements were carried out on the day of inclusion in the study (‘baseline’), 8 h later, and in the morning of the 1st, 2nd, and 3rd days thereafter. Costs for blood lactate measurements were analysed for each method.Results: A total of 197 lactate measurements were done with each system. Lactate measured from arterial blood using the Accusport® and the central laboratory showed excellent agreement (bias: −0.15 mmol/l; relative error: −2.74%). Lactate measured by the blood gas analyser had also excellent agreement with the reference method (bias: 0.09 mmol/l; relative error: 2.24%) and the hand‐held device (bias: −0.24 mmol/l; relative error: −5.06%). Time from blood sampling to availability of data was significantly longer for the central laboratory (85±35 min [range: 45–168 min]) than for both POC systems (range: 1–10 min). Total cost for measuring blood lactate was lowest using the Accusport® device.Conclusion: The trend towards miniaturizing laboratory monitoring devices will continue, resulting in greater flexibility of management of the critically ill. Blood lactate can rapidly, easily, accurately, and economically be measured at the bedside with the hand‐held monitor apparatus Accusport® and the bench‐top blood gas analyser.
On‐site coagulation monitoring does not affect hemostatic outcome after cardiac surgery
Authors: Capraro L. , Kuitunen A. , Salmenperä M. , Kekomäki R. 
Published: March 2003

Background: Rapid coagulation tests are now available for monitoring of bleeding patients after cardiac surgery. As inappropriate blood use in these patients may be due to lack of timely coagulation data, we studied the effect of an algorithm with on‐line coagulation monitoring on transfusions in these patients.Methods: Prospectively, patients bleeding (>1.5 ml kg−1 15 min−1) after cardiac surgery were randomly assigned to two groups: in group A (n=28), hemostatic treatment during the immediate recovery period (1 h after surgery) was based on an algorithm with on‐site hemostasis monitoring, whereas during the same period group B patients (n=30) were managed solely according to the clinician’s judgement; laboratory tests other than activated clotting time after heparin neutralization were prohibited.Results: Cumulative chest tube drainage up to 16 h and total transfusion requirements did not differ between the groups. Using a platelet transfusion trigger of 100×109/l, significantly more patients received platelets during the immediate recovery period in the algorithm group than in the control group (14 vs. 3 patients, P=0.001). Desmopressin acetate was administered more often in group A than in group B (8 vs. 2 patients, P=0.04).Conclusions: Algorithm‐based therapy increased utilization of hemostatic interventions during the immediate recovery period without any obvious benefit to the hemostatic outcome. Re‐evaluation of the platelet transfusion trigger seems warranted.
Effects of different preparations of propofol, diazepam, and etomidate on human neutrophils in vitro
Authors: Heine J. , Jaeger K. , Weingaertner N. , Scheinichen D. , Marx G. , Piepenbrock S. 
Published: March 2003

Background: Intravenous anaesthetics and sedatives can influence polymorphonuclear cell (PMN) functions. Some of the drugs for sedation and anaesthesia have been alternatively dissolved in lipid solutions containing medium (MCT) and/or long chain (LCT) triglycerides. The in vitro effects of two different diazepam (benzyl‐alcohol, LCT/MCT), etomidate (propylene‐glycol, LCT/MCT), and propofol (LCT, LCT/MCT) preparations on respiratory burst (RB) and phagocytosis of human PMNs were studied.Methods: Diazepam (2, 20 μg ml−1), etomidate (0.5, 5 μg ml−1), and propofol (6, 60 μg ml−1) were investigated in clinical and 10‐fold concentrations with flow cytometric assays. The RB was measured with the fluorescent dye rhodamine after induction with Escherichia coli or formyl‐methionyl‐leucylphenylalanine (FMLP) following priming with tumour necrosis factor alpha (TNF‐α). Phagocytosis of PMNs was carried out in whole blood after incubation with fluorescein‐labelled E. coli.Results: LCT‐propofol at 60 μg ml−1 reduced the percentage of PMNs with RB activity after induction with E. coli (52.8±20.4) and TNF‐α/FMLP (10.8±5.1)) as well as the percentage of phagocytosing PMNs (48.9±19.5) in contrast to LCT/MCT‐propofol, which augmented all parameters (85.4±10.1, 50.3±12.7, 66.5±12.5). Also the higher concentrations of LCT/MCT‐diluted etomidate and diazepam increased the percentage of RB positive PMNs compared to the alternative compositions. The percentage of phagocytosing PMNs was less reduced with 20 μg ml−1 LCT/MCT‐diazepam (85.2±6.9) than with the same concentration of benzyl‐alcohol diluted diazepam (68.8±12.2) compared to the control.Conclusion: The in vitro effects of diazepam, etomidate, and propofol are dependent on the solvent applied. The tested LCT/MCT preparations reduce the inhibitory effects on the bacterial killing capacity of PMNs found after incubation with propylene‐glycol, benzyl‐alcohol, or LCT preparations, respectively (
Note).
Long‐term outcome after neurosurgically treated spinal epidural abscess following epidural analgesia
Authors: Wang L. P. , Hauerberg J. , Schmidt J. F. 
Published: March 2003

Background: A recent investigation demonstrated a high incidence of epidural abscess secondary to epidural catheterization and a 50% frequency of neurologic deficits. We studied short‐ and long‐term neurologic outcome in patients operated for spinal epidural abscess after epidural analgesia.Methods: Nineteen patients who had undergone neurosurgical decompression and drainage of a spinal epidural abscess during a 5‐year period at three neurosurgical departments in East Denmark were identified by manual review of operating lists.Results: Median epidural catheterization time was 8 days (range 3–44). Preoperatively 12 patients suffered from inferior paraparesis, one had irradiating pain from the back, and 6 patients had no neurologic deficits. Postoperatively 2 patients had recovered, but 3 other patients had deteriorated; therefore, 13 patients were discharged with paresis/plegia. Seven patients died during a median follow‐up time for all patients of 41.6 months. One patient recovered completely, and one suffered from minor deficits. The remaining patients suffered from paraparesis/plegia or bladder/bowel dysfunction.Conclusion: Overall recovery rate for patients with paresis/plegia after epidural abscess was 20%. No patients with paresis/plegia following a thoracic abscess recovered in contrast to a 50% recovery rate for patients with lumbar epidural abscess. The majority of long‐term survivors had severe neurologic deficits. Abscess formation contributed to one death.
Evidence that spinal segmental nitric oxide mediates tachyphylaxis to peripheral local anesthetic nerve block
Authors: Wang C. , Sholas M. G. , Berde C. B. , Dicanzio J. , Zurakowski D. , Wilder R. T. 
Published: March 2003

Background: Tachyphylaxis to sciatic nerve blockade in rats correlates with hyperalgesia. Spinal inhibition of nitric oxide synthase with NGnitro‐L‐arginine methyl ester (L‐NAME) has been shown to prevent hyperalgesia. Given systemically, L‐NAME also prevents tachyphylaxis. The action of L‐NAME in preventing tachyphylaxis therefore may be mediated at spinal sites. We compared systemic versus intrathecal potency of L‐NAME in modulating tachyphylaxis to sciatic nerve block.Methods: Rats were prepared with intrathecal catheters. Three sequential sciatic nerve blocks were placed. Duration of block of thermal nocifensive, proprioceptive and motor responses was recorded. We compared spinal versus systemic dose–response to L‐NAME, and examined effects of intrathecal arginine on tachyphylaxis. An additional group of rats underwent testing after T10 spinal cord transection. In these rats duration of sciatic nerve block was assessed by determining the heat‐induced flexion withdrawal reflex.Results: L‐NAME was 25‐fold more potent in preventing tachyphylaxis given intrathecally than intraperitoneally. Intrathecal arginine augmented tachyphylaxis. Spinalized rats exhibited tachyphylaxis to sciatic block.Conclusion: The increased potency of intrathecal versus systemic L‐NAME suggests a spinal site of action in inhibiting tachyphylaxis. Descending pathways are not necessary for the development of tachyphylaxis since it occurs even after T10 spinal cord transection. Thus tachyphylaxis, like hyperalgesia, is mediated at least in part by a spinal site of action.
Effect of naloxone on primary and secondary hyperalgesia induced by the human burn injury model
Authors: Brennum J. , Kaiser F. , Dahl J. B. 
Published: March 2003

Background: Opioid antagonists may change the responses in models of experimental hyperalgesia. This indicates a possible involvement of the endogenous opioid system in these models. The aim of the present study was to evaluate whether activation of the endogenous opioid system could be demonstrated in the human burn injury model of cutaneous hyperalgesia, using an intravenous challenge with the non‐selective opioid antagonist naloxone.Methods: We studied 25 healthy male volunteers aged 20–31 yrs in a randomised, double‐blind, triple crossover design. A 25×50 mm rectangular burn injury was produced on the calf on 3 separate days, at least 1 week apart. Subjects received an intravenous bolus dose of naloxone 0.4 mg, 10 mg or placebo 3 h after induction of the burn injury.Results: Primary and secondary hyperalgesia was induced by the burn injury. Naloxone did not affect any of the measured variables: heat pain detection threshold in non‐injured or injured tissue, pain produced by short or prolonged noxious heat in non‐injured or injured tissue, secondary hyperalgesia elicited by pin prick or stroke, or pain produced by short or prolonged noxious mechanical stimulation in non‐injured tissue. No significant adverse effects of naloxone were encountered.Conclusions: Activation of an endogenous opioid response following induction of hyperalgesia in human volunteers by a burn injury could not be demonstrated with an intravenous naloxone challenge. These findings suggest that the endogenous opioid response is not a confounding factor in this model.
Comparison of lignocaine 2% with adrenaline, bupivacaine 0.5% with or without hyaluronidase and a mixture of bupivacaine, lignocaine and hyaluronidase for peribulbar block analgesia
Authors: Van den Berg A. A. , Montoya‐Pelaez L. F. 
Published: March 2003

Purpose: Each of the freely available local analgesic agents may be used, alone or in combination, with or without hyaluronidase, epinephrine and sodium bicarbonate for peribulbar block analgesia (PBA). A prospective audit of four solutions was undertaken to rationalize choice of local analgesic agent for PBA.Methods: A randomized, prospective study on 200 middle‐aged to elderly patients undergoing cataract extraction was undertaken to compare the efficacy of: (1) bupivacaine 0.5% (bup 0.5% plain); (2) bupivacaine 0.5% plus hyaluronidase 100 i.u. ml−1 (bup 0.5% hyalase); (3) lidocaine 2% plus epinephrine 1:200 000 (lido 2% epi); or (4) a mixture of lidocaine 2% and bupivacaine 0.5% (2:3 volume per volume mix) containing hyaluronidase 25 i.u. ml−1 (lido/bup/hyalase). A standardized deep peribulbar block technique, akinesia scoring system (each 5 min×4), and supplemental protocol was followed. Onset of block and supplementation rates to achieve akinesia were recorded by a blinded observer; the requirement for augmentation with topical oxybuprocaine or subconjunctival lidocaine during surgery and the time from first PBA injection to the completion of surgery (the duration of surgical access) were also recorded.Results: Groups (N=50) were comparable. Akinesia scores were similar after each agent at 5 min, better with lido 2% epi compared with bup 0.5% plain at 10 min (P<0.05), and better with bup 0.5% hyalase, lido 2% epi, and lido/bup/hyalase, than with bup 0.5% plain at 15 min (P<0.01, <0.01, <0.05, respectively) and at 20 min (P<0.05, <0.05, <0.025, respectively). The supplementation rate at 5 min was least with lido 2% epi, greater with bup 0.5% plain (P<0.01) and bup 0.5% hyalase (P<0.0005) and greatest with lido/bup/hyalase (P<0.0005), but similar in each group at 10, 15 and 20 min. Overall, those given lido 2% epi required the least number of supplemental injections to achieve globe akinesia. Mean supplemental injectate volumes, augmentation rates during surgery and the durations of surgical access provided by each agent were similar.Conclusion: All four agents provided adequate analgesia during cataract extraction lasting approximately 95–100 min after PBA injection. Lido 2% epi demonstrated most rapid onset and required least number of injections to establish block. A hyaluronidase effect was evident only after 15 min in the bup 0.5% hyalase and lido/bup/hyalase groups. Bup 0.5% plain was overall the least satisfactory, and the greatest supplementation rate occurred with lido/bup/hyalase, suggesting that either lido 2% epi or bup 0.5% hyalase are the most suitable of the agents tested for this type of surgery.
A comparison of 0.5% ropivacaine and 1% mepivacaine for sciatic nerve block in the popliteal fossa
Authors: Fernández‐Guisasola J. , Andueza A. , Burgos E. , Plaza A. , Porras M. C. , Reboto P. , Rivera J. C. , García Del Valle S. 
Published: March 2003

Background: The purpose of this study was to compare anesthetic efficacy and postoperative analgesia of 0.5% ropivacaine and 1% mepivacaine for sciatic nerve block in the popliteal fossa (popliteal block).Methods: A prospective, double‐blind study was carried out in 58 adult patients scheduled for outpatient foot or ankle surgery. They were randomized to receive popliteal block with 40 ml of either 0.5% ropivacaine (group R) or 1% mepivacaine (group M). An atraumatic, Teflon‐coated needle connected to a neurostimulator was used to make a single puncture using a posterior approach. The times to onset of sensory and motor block, and the need for intraoperative sedation were recorded. Before discharge, patients were asked to document the time to first analgesic use, time to return of full sensation in the foot, and their evaluation of the technique.Results: Onset time (mean±standard deviation, 95% confidence interval) of both sensory block (6.5±5.1 min, 4.47–8.49, in group R and 6.2±3.7 min, 4.83–7.69, in group M) and motor block (6.6±4.4 min, 4.81–8.23, in group R and 7.9±4.1 min, 6.29–9.53, in group M) was similar in both groups. Postoperative analgesia lasted longer in group R (15.2±5.1 h, 13.25–17.21) than in group M (5.7±1.8 h, 5.01–6.41; P<0.001). Duration of sensory block was longer in group R (20.7±6.2 h, 18.51–23.01) than in group M (6.5±1.7 h, 5.86–7.16; P<0.001). Acceptance of the anesthetic procedure was similar in both groups.Conclusion: In this study we demonstrated that both 0.5% ropivacaine and 1% mepivacaine for popliteal block produced rapid, effective and safe anesthesia but postoperative analgesia was more long‐lasting with ropivacaine.
Intracerebral microdialysis and bedside biochemical analysis in patients with fatal traumatic brain lesions
Authors: Ståhl N. , Mellergård P. , Hallström A. , Ungerstedt U. , Nordström C. H. 
Published: March 2003

Background: Microdialysis with bedside biochemical analysis was used to monitor cerebral biochemical alterations that precede and accompany increase in intracranial pressure (ICP), resulting in a complete cessation of cerebral blood flow.Methods: Seven patients, who died due to an untreatable increase in ICP, were included. The patients originate from a large, consecutive series of severely head injured patients (n: 95) monitored with intracerebral microdialysis (perfusion rate 0.3 μl/min). One microdialysis catheter was inserted via a separate burr hole frontally to that used for the intraventricular catheter (”better” position) and one catheter was inserted into cerebral cortex surrounding an evacuated focal contusion or underlying an evacuated haematoma (”worse” position). Biochemical analyses of glucose, lactate, glycerol, urea, glutamate, and pyruvate were performed at the bedside. All samples were frozen for subsequent HPLC (high‐performance liquid chromatography) analyses of amino acids and ions.Results: Decreases in glucose and pyruvate and increases in lactate, glycerol, glutamate, and lactate/pyruvate (la/py) ratio characterized cerebral ischaemia. The measured markers give information regarding substrate availability (glucose), redox state of the tissue (la/py ratio), degradation of glycerophospholipids in cell membranes (glycerol), and extracellular concentration of excitatory amino acids (glutamate). In the “worse” position biochemical deterioration occurred before the increase in ICP. In the “better” position biochemical deterioration was usually observed after the increase in ICP.Conclusion: Changes of cerebral energy metabolism that accompany cerebral ischaemia follow a certain pattern and may be detected at the bedside by intracerebral microdialysis before the secondary damage causes an increase in ICP.