bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of halothane, isoflurane and sevoflurane on calcium‐related contraction in porcine coronary arteries
Authors: Zhang X. P. , List W. F. 
Published: January 2009

Background:Volatile anaesthetics have a direct inhibitory effect upon epicardial coronary arterial smooth muscles (1–4). The site and mode of their action at the cellular level need to be clarified, which was the purpose of our study. The present investigation attempted to answer the question in what way volatile anaesthetics influence Ca2+‐related contraction in isolated porcine epicardial coronary to understand their intracellular mechanism.Methods:Isolated helical strips of porcine epicardial coronary artery without endothelium were suspended for isotonic contraction recordings in Krebs‐Ringer's solution. 9.4×10‐2MK+, 2.5×10‐1M Ca2+‐induced shortening of the strips was regarded as the reference value (100%). After incubation in Ca2+‐free solution with 10‐3M ethlene glycol bis (β‐aminoethyl ether)‐N, N‐tetraacetic acid (EGTA) for 60 minutes, the muscle strips were exposed to increasing Ca2+concentrations (10‐4‐10‐2) either in the presence or absence of 1.5 or 2.5 minimum alveolar concentration (MAC) halothane, isoflurane or sevoflurane, with 9.4×10‐2M K+bath solution.Results:All three drug groups produced apparent biphasic effects with a cumulative increase of Ca2+concentration compared with control groups. An initial increase at low Ca2+concentration was followed by a decrease of Ca2+‐activated contractions. Isoflurane affected Ca2+‐induced contraction significantly more than halothane and sevoflurane.Conclusions:The results imply that volatile anaesthetics influence Ca2+‐dependent activity of coronary smooth muscle by complex mechanisms, which involve promotion of intracellular Ca2+release and other mechanisms that alter sensitivity to calcium.
Quantitative EEG analysis as a supplement to the clinical coma scale RLS85
Authors: Matousek M. , Takeuchi E. , Starmark J. E. , Stalhammar D. 
Published: January 2009

Background: The aim of the study was to investigate the correlation between EEG indicators and clinical scores based on the RLS85 (Reaction Level Scale 85) in comatose patients. The results of a simple visual assessment of the EEG, using an arbitrary scale with typical EEG patterns, were compared with those obtained by quantitative electroencephalography (qEEG).Method: The RLS85 scores were examined in 34 patients with impaired consciousness due to brain tumours, vascular lesions or head injuries. The EEG was recorded shortly before or after the clinical examination. The semiquantitative assessment was made by visual inspection of the tracings, using an arbitrary scale where 12 EEG patterns with increasing proportion of slow activity were displayed. Parallel to the visual analysis, the EEGs were processed by means of EEG spectrum analysis and the power/amplitude in slow frequency bands was used as an indicator. The results were based on correlation between various types of EEG variables and the RLS scores which were obtained in the same patients.Results: The correlation between the visual EEG indicators and coma scores ranged between 0.53 and 0.57 (P<0.01). As regards the computerised EEG analysis, the correlation between the clinical scores and various EEG spectrum values did not exceed 0.45 (P<0.01). A higher correlation could be obtained by combining eight EEG variables; the multiple correlation coefficient was then 0.68.Conclusions: The amount of EEG slow activity is significantly correlated to the RLS85 score. This means that the EEG also provides information on the level and not only on the changes of the coma degree. Surprisingly, the indicators based on quantitative EEG, as used in commercially available instruments, did not give better results than the visual assessment. However, the results of the computerised analysis could be improved using multivariate statistical methods. The study also showed a way to improve communication between the neurophysiologist and clinician by presenting the EEG findings in terms similar to those used in the clinical scales. However, the clinician should be aware of the fact that the “EEG score” and the clinical score is not the same: the intention is to supplement rather than to simulate the clinical observation.
Effects on skeletal muscle oxygenation and capillary blood flow by adenosine‐, sodium nitroprusside‐ and acetylcholine‐induced hypotension
Authors: Gustafsson U. , Sollevi A. , SirsjÖoU A. , SjÖoUberg F. 
Published: January 2009

Background:Adenosine (ADO)‐induced hypotension during diethyl ether anesthesia has been shown to increase skeletal muscle oxygenation. Whether this beneficial effect of ADO hypotension is present also during another anesthetic technique was tested in the present study using ketamine‐xylazine anesthesia, and its actions were compared with sodium nitroprusside (SNP) and acetylcholine (ACh) induced hypotension in rabbits.Methods:Local oxygen pressure and capillary blood flow were measured with a multiwire microelectrode which was placed on the surface of the left vastus medialis muscle. The experiments were performed in three groups, in which either ADO, SNP or ACh was infused into a central vein in a dose that produced a reduction of the mean arterial pressure by 20–25%, to approximately 60 mmHg.Results:In the ADO group (60–170 μg kg‐1min‐1) the tissue oxygen pressures increased by 23% while capillary blood flow decreased by 38%. During SNP administration (1–3 μg kg‐1min‐1) the oxygen pressures decreased by 21% and an increase of 31% in capillary flows was seen. When ACh was infused (1–4 μg kg‐1min‐1) the oxygen pressures decreased by 21% and, in parallel, capillary blood flow decreased by 50%. During hypotension no low tissue oxygen pressure values (<1.5 kPa) were found in the ADO group, whereas they were present in both the SNP and ACh group.Conclusion:Compared to sodium nitroprusside and acetylcholine, adenosine appears to have an oxygen‐sparing effect in the skeletal muscle during pharmacologically induced hypotension.
Percutaneous dilatational tracheostomy
Authors: Holdgaard H. O. , Pedersen J. , Paaske P. B. , Jensen R. H. , Outzen K. E. , Hostrup P. , Juhl B. 
Published: January 2009

Methods: Fifteen patients electively selected for percutaneous dilatational tracheostomy as performed with the Ciaglia Percutaneous Tracheostomy Introducer Set are reported in this preliminary study.Results: The median time for insertion of the tracheostomy tube was 13.9 min. Complications were cuff puncture of the translaryngeal tube at an early stage of the procedure in one case, and minor bleeding controllable by the compressible effect of the dilatational procedure in three cases. During the posttracheostomy period, complications were one case of minor bleeding controllable by digital compression and one case of minor infection, i.e. cellulitis in a few millimetres around the stoma without purulent secretion.Conclusions: Our preliminary results indicate the technique as performed with the Ciaglia Introducer Set to be effective and safe with only minor complications. Furthermore, we now use it as a bedside procedure in the ICU, thus avoiding the transportation of critically. ill patients to the operating theatre. The conclusion of the superiority of percutaneous tracheostomy to dissectional tracheostomy has to await clinical randomized studies, including more patients.
Analgesic effect of intraarticular morphine. A controlled, randomised and double‐blind study
Authors: Christensen O. , Christensen P. , Sonnenschein C. , Nielsen P. R. , Jacobsen S. 
Published: January 2009

Background: Opioids produce antinociceptive effect by acting on receptors on peripheral nerves. The clinical relevance of this effect is still debated. The aim of the study was to compare the analgesic effect of morphine intraarticularly with the intramuscular route of administration after knee surgery.Methods: Sixty‐one patients, ASA 1–2, having elective arthroscopic surgery of the knee were randomised to either an intraarticular or intramuscular dose of morphine 5 mg. The pain sensation was estimated by visual analogue scale and a verbal rating score 0,1,2 and 4 hours postoperatively and verbal rating score on the third day. The use of acetaminophen and supplementary opioids were recorded for the first 4 hours postoperatively, from 4 hours until the third day, and from day 3 to day 7 postoperatively.Results: The groups were comparable. Three patients were excluded. There were no statistically significant differences in painscore and consumption of analgesics. Fifty‐nine per cent in each group had macroscopic synovitis. In the intraarticular group, there was no increased effect of morphine in the patients with synovitis compared to patients without synovitis.Conclusions: The clinical analgesic effect of 5 mg morphine given intraarticularly is equal to 5 mg morphine given intramuscularly. The occurrence of villous synovitis seems to be of no clinical importance concerning the local effect of morphine.
Pre‐emptive effect of pre‐incisional versus post‐incisional infiltration of local anaesthesia on children undergoing hernioplasty
Authors: Dahl V. , RÆder J. C. , ErnØ P. E. , Kovdal A. 
Published: January 2009

Background: Although promising in experimental studies of post‐traumatic pain, the concept of pre‐emptive analgesia is still controversial in a clinical setting. Thus, we wanted to compare the clinical efficacy of wound infiltration with local anaesthesia before surgery with wound infiltration after hernioplasty in children.Methods: Fifty children aged 2–10 years scheduled for hernioplasty were randomly assigned into two groups. Group 1 (n=28) was infiltrated before surgery with bupivacaine 2.5mg/ml, lmg/kg after induction of general anaesthesia. After surgery they were infiltrated with the same volume of 0.9% saline. Group 2 (n=22) was infiltrated with 0.9% saline before surgery and bupivacaine 2.5 mg/ml, lmg/kg after surgery. The study was performed double‐blindly. In both groups anaesthesia was induced with thiopenthone and maintained with nitrous oxide and halothane, adjusted to keep haemodynamic measurements stable. All children were given paracetamol 15–20 mg/kg rectally when admitted to the recovery ward. Painscore (OPS) and analgesic requirements were registered postoperatively. After 48 h the parents completed a standardised questionnaire and they were interviewed by telephone after one week.Results: The pre‐incisional group needed significantly less halothane during the procedure compared with the post‐incisional group (P<0.05). The pre‐incisional group also had a tendency towards faster awakening after the end of anaesthesia and a significantly lower OPS‐pain score 30 min after the operation (P<0.03). There were no differences between the two groups regarding need for additional analgesia: meperidine i.v. during the first 5 h postoperatively, and paracetamol thereafter. There were no differences between the groups regarding activity level, appetite and quality of sleep in the first week. In both groups the need for opioid analgesics was low:54% in the pre‐incisional group and 45% in the post‐incisional group did not receive any opioid analgesic treatment. The children were virtually fully recovered after the first 24 h.Conclusion: Perioperative infiltration with a local anaesthetic in children undergoing hernioplasty results in a smooth recovery with little need for opioids postoperatively. Apart from a lower anaesthetic requirement and a reduced postoperative pain level after 30 min in the pre‐incisional bupivacaine group, there was no difference between infiltration before (pre‐emptive) or after surgery.
Quantitative methodological studies of motor and sensory blockade in epidural analgesia with special reference to early mobilization and a new local anesthetic — ropivacaine
Authors: Zaric D. 
Published: January 2009

Abstract: In six studies of epidural analgesia, sensory and motor blockade caused by ropivacaine and bupivacaine was evaluated by quantitative methods. The dose response to single injections of high (0.5%,0.75% and 1%) and low concentrations (0.1%, 0.2% and 0.3%) of ropivacaine in continuous infusion was investigated. Motor blockade was measured by mechanotransducers and by average rectified electromyography. The presence of residual effects was determined by F response and H reflex recording. Quantitative methods for assessment of sensory blockade (Thermotest method, argon laser stimulation and recording of somatosensory evoked potentials ‐ SEPs) were introduced with 0.5% bupivacaine. A selection of these quantitative methods was applied during continuous epidural infusion (21 h) of ropivacaine. Mobilization was attempted throughout the infusion period. In ambulant subjects, postural control was evaluated by posturography.Motor blockade with high concentrations of ropivacaine was dose‐dependent, but only in segments close to the injection site (L2/3). In the abdominal muscles, the blockade was partial and not clearly dose‐dependent. Persistent prolongation of H reflex latency was found in five subjects who received high concentrations of ropivacaine, but not in any of those receiving continuous infusion. With 0.5% bupivacaine the zone of anesthesia was smaller, and the zone of partial blockade of thermo‐ and laser‐perception larger than that of the pin‐prick analgesia. There were no significant differences in the spatial or temporal sequence of blockade between the Thermotest and laser stimulation methods. Changes in SEPs caused by epidural blockade with bupivacaine could not distinguish between the sensory blockade of low and high intensity.During continuous infusion of 0.1% ropivacaine, motor blockade was so slight that all subjects could be mobilized, whereas with 0.2% and 0.3% ropivacaine it was moderate (40–50% of baseline force was present). The zone of analgesia was smaller with 0.1% ropivacaine than with 0.2% and 0.3% solutions. With 0.1% ropivacaine the subjects were able to perform postural tests and maintain balance, which was not the case with 0.2% and 0.3% ropivacaine. A quick recovery after discontinuation of infusion was characteristic of ropivacaine.
Effects of desflurane on systemic, preportal and renal circulatory responses to infra‐renal aortic cross‐clamping in the pig
Authors: Sundeman H. , Biber B. , Henriksson B.‐Å. , Raner C. , Seeman‐Lodding H. , Winso O. 
Published: January 2009

Background: Different pharmacological approaches have been used in the control of cardiovascular responses to surgical infra‐renal aortic occlusion (AXC). The aim of the present study was to explore the modulatory effects of desflurane (DES) on these responses.Methods: The study was performed in normoventilated chloralose‐anesthetized pigs (n=14). Measurements included cardiac output (CO), pulmonary vascular pressures, heart rate (HR) and mean arterial pressure proximal to the AXC site (MAPPROX). Renal arterial (QREN) and portal venous (QPORT) blood flows were measured ultrasonically. Systemic (SVR), preportal (RPORT) and renal (RREN) vascular resistances were derived. Sets of measurements were done a) prior to, b) during and c) 5 min after AXC. This was repeated, in a randomized fashion, at control (no DES) and with 4.9% and 9.8% DES, respectively.Results: DES decreased MAPPROX, CO, HR, SVR, RREN and RPORT. At control, AXC increased MAPPROX (+27%), SVR (+27%), QPORT (+14%), RPORT (+12%) and RREN (+43%). DES 4.9% did not change this response pattern. With 9.8% DES, the AXC‐induced increases in MAPPROX (+17%) and SVR (+21%) were attenuated. At this stage, AXC caused no demonstrable changes in RREN or RPORT, while both QREN (+16%) and QPORT increased (+9%).Conclusions: DES effectively controlled increases in proximal blood pressure during AXC. The increases in RREN and RPORT that were seen during AXC at control were inhibited by 9.8% DES. Consequently, at this DES dose, both QREN and QPORT increased during AXC.
Is sufentanil a useful opioid for laryngomicroscopy?
Authors: Steinfath M. , Scholz J. , Tonner P. H. , Kycia B. , Konietzko T. , Bause H. , Esch J. Schulte am 
Published: January 2009

Background: Alfentanil is commonly used as opioid analgesic for short surgical procedures. Little is known about the usefulness of sufentanil for this purpose. We investigated the effects of alfentanil and sufentanil on haemodynamic characteristics, catecholamine levels, and adrenocorticotropic hormone (ACTH) and Cortisol contents during elective laryngomicroscopy and short laryngeal surgery (LM).Methods: 100 patients (ASA class I or II) were randomly allocated into one of four groups to receive either 10 Hg/kg alfentanil (group I, ALF 10), 20 μg/kg alfentanil (group II, ALF 20), 0.25 μg/kg sufentanil (group III, SUF 0.25), or 0.5 μg/kg sufentanil (group IV, SUF 0.5) given intravenously before induction of anaesthesia. After administration of the opioid analgesic all patients received 2.0 mg/kg propofol, 15 μg/kg vecuronium, and 1 mg/kg succinylcholine. Anaesthesia was maintained as total intravenous anaesthesia with propofol (8 mg/kg/h) and oxygen (33%) in air. Heart rate (HR), mean arterial pressure (MAP), adrenaline (ADR), noradrenaline (NADR), ACTH, and Cortisol were measured before (baseline) and after induction of anaesthesia, at the beginning and cessation of LM, and 2 h after LM.Results: In group I (ALF 10) a significant increase in all variables was observed at the beginning and at the end of LM when compared with baseline. Two hours after LM all parameters were found to be at baseline levels. In groups II and III (ALF 20 and SUF 0.25) a significant increase in HR, MAP and catecholamine levels was observed at the end of LM compared to baseline. ACTH and Cortisol contents were unchanged throughout. In group IV (SUF 0.5) HR was significantly reduced after induction, at the beginning and cessation of LM, and 2 hours following operation, whereas MAP was only decreased after induction (P<0.05 vs. baseline). ADR, NADR, ACTH, and Cortisol were similar throughout. If the duration of surgery was shorter than 12 min (20%) in group III (SUF 0.25) and 20 min (44%) in group IV (SUF 0.5), the patients had to be treated with naloxone 10 min after cessation of LM in order to antagonize respiratory depression. This side effect was not observed in group I (ALF 10) and in only one patient (4%) of group II (ALF 20) for whom surgery lasted 5 min.Conclusion: Clinical recovery is achieved most rapidly with alfentanil in ultra short surgical procedures. However, if surgery is expected to be longer than about 12 min also sufentanil at a dose of 0.25 μg/kg seems to be useful for this kind of surgery.
Influence of body compartments on propofol induction dose in female patients
Authors: Chassard D. , Berrada K. , Bryssine B. , Guiraud M. , Bouletreau P. 
Published: January 2009

Background: For induction of anaesthesia, drugs such as pro‐pofol are commonly administered according to a per weight basis. However, drugs are primarily distributed to the fat‐free mass. This study was undertaken to determine the relationship between propofol requirement for induction and body mass determined by bioimpedance analysis (BIA) or by body mass index (BMI).Methods: Twenty‐one ASA 1 female patients scheduled for gynaecologic surgery received propofol for induction at 133 mg. min‐1. Stepwise regression analysis was used to describe the relationships between propofol requirement for loss of consciousness and age, body weight, and lean body mass measured by BIA and BMI (independent variables).Results: Loss of consciousness was obtained with a propofol dose (Mean (SEM)) of 2.170.10 mgkg‐1. Stepwise analysis showed that propofol requirement (total dose) was not proportional to weight or age but related to lean body mass as determined by BIA and to body mass index (r2 = 0.447; global P‐ value <0.007). BMI was the only regressor variable when the propofol dose was expressed in mg. kg‐1 (r2 = 0.661; P<0.001).Conclusions: Our results indicate that propofol requirements for induction are proportional to the lean body mass rather than total body weight.
Pulmonary vascular effects of nitroglycerin and isosorbide dinitrate in patients with end‐stage cardiomyopathies
Authors: Muikku O. , Hynynen M. , Salmenperä M. , Nieminen M. S. 
Published: January 2009

Background: Severe preoperative pulmonary hypertension predicts a poor outcome after heart transplantation and therefore pulmonary vasoreactivity is frequently evaluated in the pretransplantation screening. Among the i.v. organic nitrates used in this evaluation, isosorbide dinitrate and nitroglycerin differ in their pharmacokinetics, and isosorbide dinitrate has been suggested to be more selective in its effects on pulmonary vasculature than nitroglycerin.Methods: Haemodynamic effects of nitroglycerin and isosorbide dinitrate were compared in 8 patients with end‐stage cardiomyopathy. Each patient was given increasing i.v. infusion‐doses of the two nitrates in a random order and double‐blind and cross‐over fashion until the target of at least 25% decrease in mean pulmonary artery pressure was achieved.Results: A total dose of 11 (3–20) (mean, 95% confidence interval) μg kg‐1 of nitroglycerin and that of 87 (12–161) μg kg‐1 of isosorbide dinitrate were given during the infusions of 20 (14–27) and 28 (18–37) min duration, respectively. With these doses producing similar acute decreases in mean pulmonary artery pressure, both nitroglycerin and isosorbide dinitrate also showed equal effects on pulmonary and systemic vascular resistances as well as on other systemic and right ventricular haemodynamic parameters.Conclusion: We conclude that there is no difference between i.v. nitroglycerin and isosorbide dinitrate in their selectivity on the pulmonary vasculature in patients with end‐stage cardiomyopathy.