bluuebunny/crossref_metadata_2025 huggingface dataset:
A Medically Staffed Emergency Ambulance Service. Report of a 5‐year Prospective Study
Authors: Jensen N.‐H.
Published: January 2009

The results of a prospective 5‐year study of a medically staffed ambulance service are presented. There was a total of 558 turn‐outs distributed among a mixed patient material. In 192 cases, resuscitation was attempted and this proved primarily successful in 59 patients. A total of 23 of these resuscitated patients could be discharged, 19 without cerebral sequelae, two with slight brain damage and two with severe brain damage. In 44 further cases, other relevant forms of emergency treatment were administered. It is concluded that prehospital treatment at the scene of accident seems beneficial to patients with life‐threatening conditions.
The Control of Muscle Contracture by the Action of Dantrolene on the Sarcolemma
Authors: Hasall P. J. , Ellis F. R.
Published: January 2009

Although dantrolene reverses the muscle contracture seen during a malignant hyperpyrexia (MH) crisis, its site of action is not known. It has been inferred from previous work that the major abnormality in MH is in the sarcoplasmic reticulum, and that dantrolene must act on this organelle. In the present study the ability of dantrolene to control drug‐induced muscle contraction was tested. The drugs were chosen because their sites of action were known for inducing contracture. Dantrolene had no effect on contractures induced by 2:4 dinitrophenol, exerted only a minor effect on caffeine contractions, but reduced significantly the contracture produced by K+. It is postulated that the major action of dantrolene is on the sarcolemma, which may be the site of the MH abnormality.
Natural Killer Cell Activity During Premedication, Anaesthesia and Surgery
Authors: Tønnesen E. , Mickley H. , Grunnet N.
Published: January 2009

Natural killer (NK) cell activity of peripheral blood mononuclear cells was measured against K‐562 target cells in a 51Cr release assay in eight patients undergoing total hip replacement surgery. Eight consecutive blood samples were taken from each patient. A significant increase of NK cell activity was observed after premedication with diazepam per os. The activity increased further during a combined anaesthesia (thiopentone + N2O + O2 + buprenorphene + pancuronium) and remained increased during surgery. Postoperatively, NK cell activity fell and remained depressed for a period of at least 5 days. The findings of this study indicate that premedication, anaesthesia and surgery cause a rapid and transient increase in NK cell activity, followed by a decline in activity postoperatively. The transient increase in activity may be explained by mobilization of natural killer cells from extravasal space, spleen or lymph nodes into the circulation. The clinical significance of the alterations in NK cell activity is unknown and needs further investigateon.
The Effect of Instrumentation with a Telescope During Bronchoscopy on Arterial Oxygen Tension and Acid‐Base Balance
Authors: Saarnivaara L. , Tarkkanen J.
Published: January 2009

The effect of instrumentation with a telescope during bronchoscopy on the arterial oxygen tension and acid‐base status was studied in 17 unselected, anaesthetized patients using a ventilating technique based on Sanders' method (1). After ventilating the patients with a bronchoscope and a telescope in the trachea, in the left main bronchus or in the right main bronchus, the Pao2 value was always statistically significantly higher than after ventilating only with a bronchoscope. During the course of the bronchoscopy as well as after 1 h in the recovery room, the arterial acid‐base status was within normal limits and the mean Pao2 value during bronchoscopy ranged from 175 to 240 mmHg (23.3–31.9 kPa) and was 138 mmHg (18.4 kPa) in the recovery room when the patients breathed about 35% oxygen in air. The present results suggest that instrumentation with a telescope during bronchoscopy ameliorates rather than impairs the ventilation and oxygenation of the patients.
Effect of Combinations of Topical Anaesthesia, Fentanyl, Halothane or N2O on Circulatory Intubation Response in Normo‐ and Hypertensive Patients
Authors: Kautto U.‐M.
Published: January 2009

Attenuation of the circulatory intubation response was studied using the following combinations: oropharyngeal topical anaesthesia (OTA) + fentanyl 2μg/kg (F2), OTA+2% halothane with 70% nitrous oxide (H2N2O) or F2 + H2N2O. Firstly, it was observed in 48 normotensive patients that the combinations of OTA + F2 or F2 + H2N2O totally prevented the intubation response; OTA + H2N2O, on the other hand, was less effective. Secondly, the effect of OTA+F2 was studied in 26 hypertensive patients and their 26 normotensive controls of the same age group. The combination prevented the circulatory intubation response also in the hypertensive patients, whose circulatory reactions did not differfrom those of the normotensive patients. Nitrous oxide had no beneficial effect on the intubation response.
Carbon Dioxide Elimination after Acetazolamide in Patients with Chronic Obstructive Pulmonary Disease and Metabolic Alkalosis
Authors: Krintel J. J. , Haxholdt O. St. , Berthelsen P. , Brøckner J.
Published: January 2009

Acetazolamide, an inhibitor of carbonic anhydrase, which catalyzes hydration/dehydration of carbon dioxide, has been used for correction of metabolic, alkalosis in patients with chronic obstructive pulmonary disease (COPD). Animal experiments have shown that the gradient between tissue and the alveolar CO2 tension increases after inhibition of carbonic anhydrase, suggesting retention of CO2. In order to determine the true degree of carbon dioxide retention after total inhibition of carbonic anhydrase, 10 patients with COPD and pronounced metabolic alkalosis (base excess above 6) under controlled mechanical ventilation were studied. The study showed that there was a statistically significant increase in tissue Pco2 and a temporary decrease in pulmonary carbon dioxide excretion. Furthermore, it was found that Pao2 and Pvo2 increased significantly after inhibition of carbonic anhydrase, which could, at least partly, explain the improvement seen in patients with COPD and metabolic alkalosis after treatment with acetazolamide.
Intestinal Vascular Responses to Dopamine During Fentanyl‐Nitrous Oxide Anaesthesia, Supplemented with Dixyrazin
Authors: Biber B. , Martner J. , Nilsson H. , Redfors S. , Sjöwall H. , Winsö O.
Published: January 2009

Intestinal haemodynamics in response to continuous i.v. administration of dopamine were investigated in cats anaesthetized with fentanyl‐nitrous oxide either with or without supplement of dixyrazin. A dose‐dependent vasodilatation was observed in the dopamine dose range 2.5–35 μg‐kg‐1min‐1and the subsequent maximal intestinal blood flow increase was 121%. No net intestinal vasoconstriction was evident even at the largest dopamine doses, although the vascular response reached a plateau at 17.5 μg‐kg‐1min‐1. Control experiments during chloralose anaesthesia gave similar results. Changes in mean arterial pressure and heart rate were small. Renal blood flow was virtually unchanged at dopamine doses below 10 μg‐kg‐1min‐1, while renal vasoconstriction was evident following dopamine doses above that level. The addition of i.v. dixyrazin (0.15‐0.30 mg kg‐1) to the fentanyl‐nitrous oxide anaesthesia substantially potentiated the intestinal vasodilator response to i.v. dopamine and the maximal blood flow increase was 183% at 10–15 μg kg‐1min‐1.In vitroexperiments using mesenteric resistance vessels from the rat demonstrated a dose‐dependent relaxation to dopamine. At very large doses this response was counteracted, but not reversed into vasoconstriction by dopamine‐induced a‐adrenergic stimulation.
Sister Chromatid Exchanges and Structural Chromosome Aberrations in Lymphocytes in Operating Room Personnel
Authors: Husum B. , Niebuhr E. , Wulf H. C. , Nørgaard I.
Published: January 2009

Information on possible chromosomal damage in humans after long‐term exposure to trace concentrations of waste anaesthetic gases is scarce. We examined peripheral lymphocytes in operating room personnel for both chromosome aberrations and sister chromatid exchanges (SCE). Following a standardized procedure of cultivation and staining, 30 cells from each person were scored for SCE and 100 cells from each person were examined for chromosome aberrations. A total of 45 persons were examined, representing anaesthetists (n= 15), operating room nurses assisting the surgeon (n=10), nurses circulating in the operating room (n = 8) and healthy, unexposed controls (n = 12). The median duration of working in the operating room was 102 months, 66 months and 66 months, respectively. Time‐weighted concentration levels of 2.5‐4.3 p.p.m. of halothane and 25–400 p.p.m. of nitrous oxide were measured in the breathing zones of the anaesthetists during mask anaesthesia. Examination of SCE and chromosome aberrations yielded corresponding qualitative results. With both tests, no statistically significant difference was observed between the four groups of persons. It was concluded that by examination of both SCE and chromosome aberrations in peripheral lymphocytes in operating room personnel, no indication was found of a mutagenic effect of long‐term exposure to trace concentrations of waste anaesthetic gases.
Influence of Moderate Alcohol Intake on Wakening Plasma Thiopental Concentration
Authors: Loft S. , Jensen V. , Rørsgaard S.
Published: January 2009

In an earlier study, an inverse correlation between thiopental‐induced sleeping time and alcohol intake in the preceding week was demonstrated in women undergoing termination of pregnancy. In order to investigate the mechanism behind the apparent cross‐tolerance, the relationship between alcohol consumption in the week preceding thiopental/nitrous oxide/oxygen anesthesia and wakening plasma thiopental concentration on one hand and sleeping time on the other was examined in 68 women scheduled for termination of pregnancy and in 37 women scheduled for diagnostic uterine dilatation and curettage. In terms of pure alcohol, the weekly intake (mean ± s.d.) was 1.17±2.07 ml kg‐1in the former and 1.49± 1.70 ml kg‐1in the latter group. A positive correlation between alcohol consumption and wakening plasma thiopental concentration was found in both groups, reaching statistical significance (P< 0.05) in the group undergoing termination of pregnancy, but not in the other. The inverse correlation found earlier between alcohol intake and sleeping time was not reproduced significantly in any of the groups. The results indicate that moderate alcohol intake may induce cerebral tolerance to thiopental.
Differential Ventilation in Acute Bilateral Lung Disease. Influence on Gas Exchange and Central Haemodynamics
Authors: Baehrendtz S. , Santesson J. , Bindslev L. , Hedenstierna G. , Matell G.
Published: January 2009

Eight patients with acute respiratory failure (ARF) due to diffuse and rather uniform lung disease were intubated with a double‐lumen bronchial tube and ventilated in the lateral decubital position by two synchronized ventilators. Ventilation of each lung was individually adjusted to match the expected regional blood flow (differential ventilation). When ventilation with equal volumes (i.e. 50% of tidal volume to each lung) was performed, a 19% reduction of venous admixture (P<0.001) and a 22% increment in arterial oxygen tension (P<0.001) were seen. Comcomitantly, the cardiac output increased by 17% (P<0.001), to which a reduced pulmonary vascular resistance may have contributed. The net result was a 14% increment of the oxygen availability (P<0.001). An attempt to go further, giving 2/3 of the tidal ventilation to the dependent lung, was made on six of the patients. However, this ventilatory pattern did not further improve the gas exchange and also had detrimental effects on the haemodynamics. It is concluded that differential ventilation with equal tidal volumes in the lateral position can substantially improve gas exchange and central haemodynamics in patients with ARF due to diffuse lung disease.
Spinal Analgesia with Bupivacaine, Mepivacaine and Tetracaine
Authors: Bengtsson M. , Edström H. H. , Löfström J. B.
Published: January 2009

Spinal analgesia with bupivacaine, tetracaine and mepivacaine was studied in 103 patients in two studies, one open and one double‐blind. Injections were given with the patients sitting and they remained seated for 2 min after the injection. Regardless of the agent used, the mean cephalad spread of analgesia was T6‐8 15 min after injection. Mepivacaine 4% (60 mg) in glucose produced analgesia and motor blockade of good quality but of short duration. Bupivacaine 0.5% and 0.75% and tetracaine 1%, all solutions with glucose, produced long‐lasting blockades, tetracaine H mg having a longer duration of action than 15 mg bupivacaine. When 15mg of bupivacaine was administered in solutions containing glucose, no difference in sensory blockade was seen, regardless of volume (2 or 3 ml, 0.75% and 0.5%, respectively) injected. 3 ml of bupivacaine 0.75% (22.5 mg) in glucose‐free solution produced a very long‐lasting blockade with deep motor engagement, particularly suitable for hip surgery of long duration. Bupivacaine 0.75% (3 ml, 22.5 mg) in solution with glucose produced a more marked effect on the blood pressure than the other solutions tested.
The Epileptogenicity of Neurolept Anaesthesia in Patients During and After Neuroradiological Examinations with Metrizamide
Authors: Rudehill A. , Gordon E. , Grepe A. , Widén L.
Published: January 2009

Previous experimental studies caution against the use of neurolept anaesthesia during subarachnoid injection of metrizamide for neuroradiodiagnostic procedures because of severe epileptogenic complications. To examine whether these recommendations are relevant in the clinical situation or not, 104 patients were studied. They underwent neuroradiological investigations with metrizamide subarachnoidally and were anaesthetized with neurolept anaesthesia either during the investigation (59 patients, Group I) or within 48 h afterwards (45 patients, Group II) when a neurosurgical operation was performed. In 10 patients of Group I, EEG was recorded during the investigation. All patients were observed for occurrence of clinical epileptic manifestations during and after the anaesthesia. Apart from one patient who had a short episode of suspected epileptogenic EEG‐activity shortly after the injection of metrizamide, none of the other patients showed EEG‐abnormalities of epileptogenic type and none of them had any clinical signs of epileptic manifestations. On the basis of the results of this clinical study it is concluded that neurolept anaesthesia does not increase the risk of epileptic complications during neuroradiological investigations with metrizamide.
Blood Levels of Bupivacaine After Single Dose, Supplementary Dose and During Continuous Infusion in Axillary Plexus Block
Authors: Tuominen M. , Rosenberg P. H. , Kalso E.
Published: January 2009

The material consisted of 25 patients undergoing orthopaedic or plastic surgery of the upper extremity, including seven cases of replantation surgery. The total doses of bupivacaine, 150–267 mg as a single dose, 280–440 mg as a supplementary dose and 247–629 mg as a continuous infusion, resulted in maximum venous concentrations of 0.68‐3.33 μg/ml, 1.21‐2.44 μg/ml and 0.51‐1.89 μg/ml, respectively. These usually occurred 30–60 min after the injection of bupivacaine and always following the second injection when a supplementary dose was needed. The highest individual value noted occurred 15 min after single injection, possibly as a result of an exceptionally rapid absorption. Despite the high doses and the rather high venous peak concentration of bupivacaine in some of the patients, no toxic side‐effects were observed during the block or during the recovery period.
The Anatomical Shape of the Airway During Endotracheal Intubation
Authors: Alexopoulos C. , Larsson S. G. , Lindholm C.‐E.
Published: January 2009

The shape of the airway during endotracheal intubation was studied from lateral radiographs of patients lying supine on the operating table, with the neck in the normal, extended and flexed position. A computer programme calculated the anterior contour of the tube and the posterior contour of the airway as mean values of the original contours on the radiographs. The mean configuration of the airway in intubated individuals was then presented in a standard coordinate system. The results were compared with the shape of the airway in the same patients before intubation. This study and a previous one (1) have provided relevant data concerning airway anatomy that can be used in standardized testing of tube deformation forces. Our results also showed that patients were routinely placed on the operating table with the head in an unnecessarily extended position. Such a position may partly obstruct the blood flow in the vertebral arteries. An improvement in operating table design is desirable to facilitate optimal positioning of the patient's head during routine surgery.
The Conformity of an Anatomically Shaped Endotracheal Tube to the Shape of the Airway
Authors: Alexopoulos C. , Larsson S. G. , Lindholm C.‐E.
Published: January 2009

The conformity of a pre‐shaped endotracheal tube to the shape of the airway during endotracheal intubation was studied from lateral radiographs in patients lying supine on the operating table, with the neck in the normal, extended and flexed positions. A computer programme calculated the anterior contour of the pre‐shaped tube and the posterior contour of the airway as mean values of the original contours on the radiographs. The mean configuration of the airway in intubated individuals with a pre‐shaped endotracheal tube was then presented in a standard coordinate system. The results were compared with the shape of the airway in non‐intubated patients and in patients intubated with a standard endotracheal tube.
Airway Complaints and Laryngeal Pathology after Intubation with an Anatomically Shaped Endotracheal Tube
Authors: Alexopoulos C. , Lindholm C‐E.
Published: January 2009

In a group of 100 patients intubated with standard polyvinyl chloride (PVC) endotracheal tubes, 26 spontaneously complained of airway discomfort postoperatively. A further 55 patients complained of airway discomfort upon direct questioning. In a comparison group of 100 patients intubated with PVC orotracheal tubes shaped to conform with the anatomy of the airway, the corresponding figures were 14 and 21. Laryngoscopy before and 5 days after intubation revealed that among patients intubated with standard tubes there was a significantly higher frequency of mucosal lesions at the cricoid plate and at the posterior commissure of the larynx, but lesions at the medial side of the arytenoids occurred to approximately the same extent in the two groups.
Midazolam and Fat‐Emulsion Diazepam as Intramuscular Premedication A Double‐Blind Clinical Trial
Authors: Mattila M. A. K. , Suurinkeroinen S. , Säilä K. , Himberg J.‐J.
Published: January 2009

Sixty female patients were given, in random order, under double‐blind conditions, either midazolam or fat‐emulsion diazepam, intramuscularly, as premedication, 1 h before general anaesthesia. The dose of midazolam used was 0. 13mg/kgand that of diazepam 0.17 mg/kg. The degree of sedation, mood of the patient, and time at which onset of effect was perceptible were assessed before induction of anaesthesia, together with skin temperature and concentrations of midazolam or diazepam in plasma. Patients were interviewed postoperatively to discover their subjective evaluation of the premedication and to assess its amnesic effects. Midazolam was significantly superior (P<0.05) to diazepam as regards sedation. There were no differences in effects on mood of the patients between the two groups. Sixteen patients in the diazepam group and four in the midazolam group had no perception of onset of effect. The difference is significant (P<0.01). The skin temperature was, on average, 2°C higher in the midazolam group than in the diazepam group (P<0.005). The mean plasma concentration was 67.8 ±24.5 μg/l in the midazolam group and 44.8 ±25.7 μg/l in the diazepam group. In only two cases was the concentration of diazepam above 100 μg/l (arbitrarily defined as the minimum sedative concentration). Subjective evaluation of efficacy significantly (P<0.002) favoured midazolam. Local pain was evident in two patients in the diazepam group, and three patients experienced nausea immediately after administration of the drug. Intramuscularly administered midazolam seems to be a very satisfactory premedicant, with a rapid onset of sedative effect, and good tolerance. Fat‐emulsion diazepam cannot be recommended for intramuscular administration because it is not well absorbed.
Studies of Body Temperatures, Blood Lactate, Cortisol and Free Fatty Acid Levels During Exercise in Human Subjects Susceptible to Malignant Hyperpyrexia
Authors: Campbell I. T. , Ellis F. R. , Evans R. T. , Mortimer M. G.
Published: January 2009

Body temperature at a variety of sites (external auditory meatus, rectum, thigh, chest wall, pad of thumb), blood cortisol, lactate and free fatty acid levels and urinary adrenaline, noradrenaline and dopamine excretion were measured in five human subjects susceptible to malignant hyperpyrexia (MHS) and five normal subjects during a period of progressively severe exercise, starting at rest and going up to an exercise intensity producing heart rates in excess of 180 beats/min. In addition, results are reported of a further study of rectal temperature measurements made during a period of mild exercise in a different group of nine MH susceptible and nine non‐susceptible subjects. The results of the progressive exercise study indicated that as the exercise increased in severity, central (external auditory meatal) temperature rose more in the MHS subjects than it did in the controls. Thumb temperature in both groups rose with exercise but in the MHS subjects this rise was significantly delayed compared with the control subjects. It was thought that this was due to a delay in the onset of vasodilatation which usually accompanies high intensities of exercise. Serum free fatty acids and cortisol levels rose more in the MHS subjects than the controls and during the early stages of exercise blood lactate concentrations in the MHS subjects were higher than in the controls group. During mild exercise, rectal temperature in the MHS subjects was lower than in the controls. It was concluded that the pattern of temperature change was evidence of an abnormality of the heat dissipation mechanisms in the MHS subjects. This, together with the rise in the free fatty acids, could indicate an abnormality of sympathetic activity in individuals susceptible to malignant hyperpyrexia.
Anaesthetic Uptake by the Goldfish: Effect of Respiratory Rate
Authors: Chalon J. , Martin P. , Roberts C. , Ramanathan S. , Katz R. , Turndorf H.
Published: January 2009

In order to assess the uptake of halothane by the goldfish, the respiratory rate of six fish was studied when water temperature was varied with and without changes in oxygen or carbon dioxide tension. The effective dose 50 of halothane (ED‐50‐H) and the time taken to reach it (T‐ED‐50‐H) at an Fio2 of 0.35 in nitrogen, were studied when temperature and CO2 tension were varied. Nomograms were drawn to predict respiratory rate as a function of water CO2 tension, when CO2 was bubbled in air or in oxygen, and with changes in water temperature. At low temperatures (5°C to 7.5°C), respiratory rate remained below 10 per min, irrespective of CO2 partial pressure. At28°C, a CO2 partial pressure of 8 ±0.2 kPa produced a respiratory rate of 125±3/min in air, and in oxygen unexpectedly 140±3/min. Halothane ED‐50 varied with temperature (0.8% at 10°C and 1.6% at 23°C). Time to reach ED‐50‐H decreased with increases in respiratory rate, but increased as water temperature was elevated.
Respiratory Effect of THIP, a GABA‐Agonistic Analgesic, During Halothane Anaesthesia
Authors: Valentin N. , Bank‐Mikkelsen O. K.
Published: January 2009

THIP, 4, 5, 6, 7‐tetrahydroisoxazolo (5, 4‐) pyridin‐3‐ol, is a GABA‐agonistic drug with analgesic effect, but apparently without respiratory depressant properties in awake subjects. The effect of THIP on the CO2 ventilation response was tested before, during and at the end of halothane anaesthesia in six male patients and compared to a control group. As there was no indication of respiratory depression by THIP, the drug may have a future in the treatment of postoperative pain if an analgesic effect is confirmed under clinical conditions.
Subdural Haematoma. A Rare But Life‐Threatening Complication after Spinal Anaesthesia
Authors: Rudehill A. , Gordon E. , Rähn T.
Published: January 2009

A 70‐year‐old patient developed severe headache after spinal anaesthesia. He was treated with an epidural autologous blood patch with only temporary relief. Three weeks after the spinal anaesthesia, the headache became more intense and was accompanied by nausea and vomiting. A second epidural blood patch was performed without effect. The patient became unconscious and an acute CT scan revealed a large subdural haematoma. This was immediately evacuated and the patient made a good recovery. This case demonstrates that subdural haematoma should be considered as a possible aetiology in severe postspinal headache.
Effects of Oxygen on Central Haemodynamics and Va/Q Distribution after Coronary Bypass Surgery
Authors: Anjou‐Lindskog E. , Broman L. , Broman M. , Holmgren A.
Published: January 2009

Central haemodynamics and ventilation‐perfusion (V̇a/Q̇) distribution were studied in 16 patients, 21 h after coronary bypass surgery, during ventilation with FIO2 = 0.3 and 1.0. V̇a/Q̇distributions were determined by the multiple inert gas elimination technique. In 15 patients with normal preoperative lung function, there was a significant shunt of 7.5% of cardiac output and perfusion of regions with V̇a/Q̇ between 0.005‐0.1 of 2.4% (FIO2 = 0.3). Mean V̇a/Q̇ for the Q̇‐distribution was 0.89 with log s.d. of 0.92. Ventilation of regions with V̇a/Q̇ above 100 was 0.22. After 30 min of ventilation with Fio2 = 1.0, there was a slight increase in cardiac output while pulmonary arterial mean pressure and pulmonary vascular resistance showed slight decreases. There was a marked increase of the shunt in three patients but the increase for the whole group was not significant. Perfusion of regions with low V̇a/Q̇ (0.005‐0.1) increased significantly to 8.7% while the distribution of ventilation remained unchanged. The changes in distribution of Q̇ were probably due to a release of hypoxic vasoconstriction in combination with complete or incomplete alveolar collapse. One patient with obstructive lung disease showed only minor changes in perfusion distribution.
Recovery after General Anaesthesia for Laparoscopy
Authors: Hovorka J. , Lehtinen A.‐M. , Kalli I.
Published: January 2009

Recovery after two methods of light general anaesthesia for gynaecological laparoscopy was studied. For this purpose, 30 patients were divided into two equal groups (A and B). The patients in group A were anaesthetized with thiopentone, fentanyl and suxamethonium infusion, while the patients in group B received inhalation anaesthesia with enflurane and suxamethonium infusion. Both groups were normoventilated with nitrous‐oxide and oxygen mixture. A battery of recovery tests was applied in the recovery room. The patients who received inhalation anaesthesia with enflurane scored better in the recovery tests, and reached preoperative values after 3 h in the recovery room. Inhalation anaesthesia with enflurane was accepted well by the patients and provided good working conditions for the surgeons. It is suitable for outpatient gynaecological laparoscopy because it ensures rapid recovery.
Ventilation‐Perfusion Relationships During Epidural Analgesia
Authors: Lundh R. , Hedenstierna G. , Johansson H.
Published: January 2009

Resting lung volume (FRC), airway closure (CC) and ventilation‐perfusion relationships, using the multiple inert gas elimination technique, were studied during epidural analgesia. The material consisted of 10 patients, 55–84 years of age. Epidural blockade (9–13 ml mepivacaine‐adr. 1/200,000) was instituted to an upper level corresponding to Th3‐Th6. Minute ventilation and breathing frequency remained unchanged during the epidural block, while cardiac output was significantly increased (4.80‐5.74 1/min). The relationship between FRC and CC (FRC‐CC) was unchanged during the block, indicating an unchanged magnitude of airway closure. Multiple inert gas elimination data revealed virtually unchanged distribution of ventilation and perfusion during the epidural block in 9 of the 10 patients. It is concluded that lumbar epidural analgesia up to Th3‐Th6 does not influence the degree of airway closure, nor does it cause V̇a/Q̇. mismatching as general anaesthesia does.
Effects of Enflurane‐Nitrous Oxide Anaesthesia and Surgical Stimulation on Regional Coronary Haemodynamics in a Patient with LAD Bypass Graft
Authors: Reiz S.
Published: January 2009

Central and regional coronary haemodynamics were studied in a patient with a left anterior descending artery (LAD) graft and angiographically visible collaterals from a normal right coronary artery. A three‐thermistor thermodilution catheter was used for measuring total coronary sinus blood flow and great cardiac venous blood flow, the latter being a good representative of blood flow through the LAD. Enflurane‐nitrous oxide anaesthesia induced marked coronary vasodilatation and redistribution of blood flow from the LAD to other areas draining into the coronary sinus. The most likely mechanism for the redistribution of blood flow in this patient was steal via the collaterals between the LAD and the right coronary artery. During surgical stimulation, the flow through the LAD was further compromised due to pronounced coronary vasoconstriction, probably mediated by catecholamine release.
Measurement of Cardiac Stroke Volume During Cesarean Section: A Comparison Between Impedance Cardiography and the Dye Dilution Technique
Authors: Milsom I. , Forssman L. , Biber B. , Dottori O. , Sivertsson R.
Published: January 2009

Simultaneous determination of cardiac stroke volume by impedance cardiography and the dye dilution technique was compared in ten women undergoing elective cesarean section performed under general or epidural anesthesia. The influence of delivery and the anesthetic procedures used on stroke volume determination by the two methods was evaluated and compared. The correlation coefficients for measurements performed before and during anesthesia showed little variation and were largely unchanged after delivery of the child (r = 0.90‐0.97). Mean stroke volume determined by impedance cardiography was significantly (P<0.001) lower than mean stroke volume calculated from the dye dilution technique. However, there was no significant difference between the mean change in stroke volume determined by the two techniques during serial measurements. Impedance cardiography was found to be a safe, reliable, non‐invasive technique for the measurement of changes in stroke volume during cesarean section. The ability of the impedance method to determine changes in stroke volume was unaffected by the anesthetic procedures employed or by delivery of the child.
Five Non‐Depolarizing Muscle Relaxants in Precurarization
Authors: ErkolaM.D O. , Salmenperä A. , Kuoppamäki R.
Published: January 2009

Five different non‐depolarizing muscle relaxants and a control solution of saline were studied as precurarization agents. Two hundred and twenty‐two surgical patients (ASA I‐II) were allocated in a double‐blind fashion to one of the following groups: d‐tubocurarine 0.05 mg/kg, alcuronium 0.03 mg/kg, pancuronium 0.01 mg/kg, gallamine 0.25 mg/kg, ORG NC‐45 (vecuronium) 0.01 mg/kg and saline solution 0.005 ml/kg. Pretreatment was performed 4 min before administering a 1.5 mg/kg bolus of succinylcholine (SCh). Fasciculations, intubation conditions, duration of neuromuscular blockade after SCh, serum potassium changes and postoperative myalgias (in 60 patients) were recorded. All the drugs studied prevented fasciculations significantly (P<0.05) more than in the control group. d‐Tubocurarine and alcuronium were superior to the others in this respect. Intubation conditions were best in the control and pancuronium groups, but there was no significant difference between the pancuronium and d‐tubocurarine or between the d‐tubocurarine and alcuronium groups. Pancuronium pretreatment prolonged the SCh block significantly, whereas other agents shortened the duration of the SCh block. The antagonism of the SCh block apparently also affected intubation conditions, although intubation remained satisfactory. A statistically significant rise in serum potassium level was measured only in the control and pancuronium groups. In the control and pancuronium groups, four patients out of 10 had postoperative myalgias, whereas in the other groups only one or none out of 10 had them (0/10 vs. 4/10; 0.10>P>0.05). In conclusion, d‐tubocurarine and alcuronium seem to have advantages over pancuronium, ORG NC‐45 and gallamine for precurarization.
Stimulation of Drug‐Metabolizing Enzymes by Nitrous Oxide in the Rat
Authors: Peduto V. A. , Masini E. , Ludovici M. , Pieraccioli E. , Dolara P. , NovelliM.D G. P.
Published: January 2009

Wistar male rats were subchronically (150 h continuously) or chronically (5 h daily for 15 days) exposed to a 50% nitrous oxide/oxygen mixture. As an index of enzyme induction liver N‐demethylase and benzo(a)pyrene‐hydroxylase activities, serum γ‐glutamyltranspeptidase activity, urinary d‐glucaric acid and pentobarbital sleeping time were evaluated in comparison with a control group. No effect was observed after subchronic exposure to the anaesthetic gas. Chronic exposure, on the contrary, decreased pentobarbital sleeping time, increased urinary d‐glucaric acid, liver N‐demethylase and serum γ‐glutamyltranspeptidase activities. No increase of liver benzo(a)pyrene‐hydroxylase was observed. Chronic nitrous oxide exposure under appropriate conditions can modify some enzymes, metabolizing drugs and xenobiotic compounds.
Plasma Cholinesterase Levels Following Pancuronium and Vecuronium
Authors: MirakhurM.D. R. K. , Ferres C. J. , Lavery T. D.
Published: January 2009

Plasma cholinesterase levels were measured in 52 patients following administration of pancuronium 1 mg/70kg (10 patients) and 0.1 mg/kg (10 patients) and vecuronium in doses of 1 mg/70 kg (10 patients), 0.1 mg/kg (10 patients) and 0.2 mg/kg (12 patients). Both doses of pancuronium produced a significant (P<0.05 ‐<0.005) reduction in the enzyme levels. Vecuronium in a dose of 1 mg/70 kg was without any significant effects but the two higher doses produced a dose‐related reduction of about 8 and 16% in the enzyme levels, respectively, which was statistically significant (P<0.05 ‐<0.001).
Influence of Dixyrazine on Intestinal and Renal Vasoconstrictor Responses During Fentanyl‐Nitrous Oxide Anaesthesia
Authors: Winsö O. , Biber B. , Holm C. , Martner J.
Published: January 2009

In cats (n=24) anaesthetized with fentanyl‐nitrous oxide and diazepam, stimulation of the hypothalamic defence‐alarm area (DA) or afferent activation of somatic pain fibres (SA), elicited a pronounced increase in intestinal (DA 297%, SA 107%) and renal (DA 214%, SA 90%) vascular resistance as well as a decrease in diuresis. These stress‐related responses were markedly counteracted by dixyrazine (0.15‐0.5 mg · kg‐1 b.w. i.v.), especially in the kidney where the subsequent increase in vascular resistance to DA and SA stimulations amounted to only 25% and 13%, respectively, while diuresis increased. Corresponding data for stimulation‐induced increases in intestinal vascular resistance after dixyrazine were DA 156% and SA 28%. Dixyrazine is suggested to act both through interaction with peripheral α‐adrenergic mechanisms in control of vascular tone and through central nervous cardiovascular reflex depression. In man (n=7), during a similar form of anaesthesia, portal vein blood flow (1137±177 ml) was measured by the continuous thermodilution method. Preportal tissue vascular resistance during surgery decreased significantly (11.3 vs 8.7 kPa · min ml‐1 · 10‐3) after i.v. dixyrazine (0.15mg · kg‐1 b.w.). A concomitant increase in oxygen uptake in preportal tissues occurred (19.9 ml min‐1 vs 24.5 ml · min‐1).
The Effect of Local Scavenging on Occupational Exposure to Nitrous Oxide
Authors: Carlsson P. , Ljungqvist B. , Hallén B.
Published: January 2009

Despite evacuation of excess anaesthetic gases at the expiratory valve of the anaesthetic circuit and a general ventilation system producing 17–20 air changes per hour, mask anaesthesia often causes occupational exposure to anaesthetic gases exceeding the threshold limit values. The effect of a local air exhaust system, a local scavenger, on occupational exposure to nitrous oxide during paediatric mask anaesthesia was studied. The scavenger evacuated 140 m3 of air per hour and was placed at a distance of 20 cm from the face mask. In a very poorly ventilated operating theatre the exposure to nitrous oxide was reduced by 75% during the anaesthetic sessions and exposure to concentrations above 500 ppm was almost eliminated. The experiences from the installation and clinical use are discussed. Local scavenging is an excellent complement to the scavenging of excess gases at the expiratory valve, and it may be considered an alternative to expensive, high‐capacity ventilation systems.
Effect of Tubocurarine and Decamethonium on Voluntary Muscle Contractions in Man
Authors: Secher N. H. , Rube N. , Secher O.
Published: January 2009

Six healthy, young male subjects performed repeated brisk maximal voluntary muscle contractions (MVC) with the knee and hip extensors. Three MVGs were performed every minute. On separate days decamethonium 0.03 mg×kg‐1 and tubocurarine 0.01 mg×kg‐1 were administered intravenously during repeated MVCs. While ordinary MVCs showed a slow rate of rise of tension over approximately 1 s, brisk MVCs showed a steep rate of rise of tension and a biphasic configuration appeared, as a notch was seen 370–480 ms after the initiation of the contraction curve. An arbitrary straight line was drawn connecting the starting point of the contraction curve and the notch. The tension time integral to the left and above this line (α component), respectively to the right and below the line (β component) was measured during the first 600 ms of the contraction. Tubocurarine affected the β component until 70% reduced. With further curarization, the remainder of the β component was reduced together with the a component. Decamethonium, in contrast, affected the α component together with 30% of the β component. Thereafter, the rest of the β component was increasingly affected. The results suggest that the isometric mechanogram is composed of a phasically active component with a high innervation threshold primarily sensitive to decamethonium, and a tonicaily active component with a lower innervation threshold, and primarily sensitive to tubocurarine.
Distribution of Expiratory Gas and Rebreathing in T‐piece Modifications Used in Weaning
Authors: Hartmann‐Andersen F. , Andersen P. K. , Olsen J. E. , Jakubaszko J.
Published: January 2009

The simple T‐piece is frequently used as a weaning system during respirator treatment. It is modified with an expiratory non‐compliant reservoir (EnCR), an inspiratory compliant reservoir (ICR) and/or an expiratory one‐way valve. The distribution of expiratory gases and rebreathing were studied in a model set‐up in the corresponding systems at different fresh gas flows (FGF) and tidal volumes (VT). An EnCR produces no change, whereas an ICR causes the expiratory gas to flow into the inspiratory limb, an effect which is intensified by the presence of an expiratory valve. With a falling FGF and a rising VT, increasing amounts of expiratory gas are found in the inspiratory limb in the modifications with an ICR. However, this only gives rise to rebreathing in the valve modification with a low FGF and high VT. The modification of the T‐piece with an ICR but without a one‐way valve is advantageous, as this system combines only slight dilution via the expiratory limb and a minimal risk of rebreathing.
Pharmacokinetics and Pharmacodynamics of Thiopental in Patients Undergoing Renal Transplantation
Authors: Christensen J. H. , Andreasen F. , Jansen J.
Published: January 2009

The effects and pharmacokinetics of thiopental were studied in eight patients undergoing renal transplantation. The results were compared with findings in a group of patients with normal renal function. No differences were observed in induction doses or between arterial or venous sleep concentrations. The average V3in the renal failure group was 1441 or 2.5 times the value of the control group (P<0.01). The apparent differences indicating longer elimination half‐lives and higher serum clearances in the renal patients were not significant. The average binding of thiopental to serum protein shortly after the induction was 83.9 % (78.2–88.1) in the renal patients and 89.0% (85.2–91.6) in the control patients (P<0.05). The difference in V3could be explained by the differences in protein binding and when the serum clearance was calculated by using the unbound fraction, this “intrinsic clearance” was significantly lower in the renal failure group (P<0.05). Haemodynamic parameters were determined during the initial 5 min. No significant difference was observed between the thiopental‐induced changes in stroke volume. Cardiac output was unchanged in both patient groups.
In Vivo Induced Malignant Hyperthermia in Pigs. I. Physiological and Biochemical Changes and the Influence of Dantrolene Sodium
Authors: VerburgM.D. M. P. , Oerlemans F. T. J. J. , Bennekom C. A. van , Gielen M. J. M. , Bruyn C. H. M. M. de , Crul J. F.
Published: January 2009

The effects of an induced malignant hyperthermia (MH) crisis have been studied in the intact pig. Both physiological and biochemical changes in skeletal muscle were studied. MH was induced with 3% halothane plus a bolus injection of succinylcholine. In the prechallenge period a significant difference was observed in the concentration of certain muscle metabolites, comparing the MH‐susceptible (MH+) with the non‐susceptible (MH‐) pigs. A lower level was measured for phosphocreatine (PCr), inosine monophosphate (IMP) and an increased level of lactate and creatine (Cr) in the susceptible pigs (MH+). The challenge caused a significant reduction of the level of PCr and adenosine in MH+ pigs, compared to the prechallenge period. After administration of dantrolene sodium, a significant decrease was measured in the level of lactate, compared to the prechallenge period as well as during the challenge. In contrast, in the control pigs no significant changes were observed in muscle metabolites, either after induction of MH or after the administration of dantrolene sodium. Enzyme activity determinations of muscle adenylate kinase and adenosine monophosphate (AMP)‐ deaminase did not show any difference in activity either before or during the MH crisis or after treatment with dantrolene sodium. The earliest physiological change during an induced MH crisis in our study was thrapid increase of the end‐tidal CO2. Within 5 min after MH induction, end‐tidal CO2 was doubled. It is concluded that the monitoring of the end‐tidal CO2 is essential to diagnose MH at a very early stage.
In VivoInduced Malignant Hyperthermia in Pigs II. Metabolism of Skeletal Muscle Mitochondria
Authors: Ruitenbeek W. , Verburg M. P. , Janssen A. J. M. , Stadhouders A. M. , Sengers R. C. A.
Published: January 2009

The biochemical characteristics of skeletal muscle mitochondria of malignant hyperthermia (MH) susceptible Dutch Landrace pigs have been investigated before and during an MH attack, inducedin vivoby halothane plus succinylcholine. The muscle homogenates have a decreased capacity to synthesize ATP and creatine phosphate during the MH period. Muscle mitochondria prepared from susceptible pigs in an MH period consume less oxygen than do mitochondria isolated before the attack, or mitochondria from control pigs during the challenge. The oxidative phosphorylation is not uncoupled during the critical period. The production of CO2 indicates that thein vitromeasured capacity of the MH muscle mitochondria correctly reflects thein vivocondition during the MH attack. The restricted synthesis may be caused by a factor, finding expression in the mitochondria themselves, and obtained or activated during the MH attack.
Effects of Nitroglycerin on Central Haemodynamics and V.A/Q. Distribution During Ventilation with F102= 1.0 in Patients After Coronary Bypass Surgery
Authors: Anjou‐Lindskog E. , Broman L. , Broman M. , Holmgren A.
Published: January 2009

The effects of nitroglycerin (TNG) infusion during ventilation with F102 = 1.0 on central haemodynamics and the distribution of ventilation ‐ perfusion (V.A/Q.) were studied with the multiple inert gas elimination technique in eight patients after coronary bypass surgery. Administration of TNG resulted in a significant decrease in mean arterial pressure, and an increase in heart rate while cardiac output remained unchanged. Mean right atrial, pulmonary arterial and pulmonary wedge pressures all decreased. There was a significant reduction in PaO2 from 50.5 to 32.7 kPa, while PaO2 remained unchanged in a control group of eight patients. This was mainly due to an increase in shunt from 9.3 to 16.5% of cardiac output during TNG‐infusion. In the control group there was also an increase in shunt from 9.7 to 12.1 % of cardiac output with a simultaneous decrease of the same magnitude in perfusion of regions with low V.A/Q.(0.005‐0.1). This was not evident in the group receiving TNG. Twenty min after termination of TNG‐infusion the effects on central haemodynamics and gas exchange were not fully reversed. The mechanism behind the increase in inert gas shunt observed with infusion of TNG during oxygen breathing is probably a selective effect on vessels with remaining high vasomotor tone despite high alveolar oxygen tension.
Piroxicam, Acetylsalicylic Acid and Placebo for Postoperative Pain
Authors: BreivikM.D. H. , Stenseth R. , Apalseth K. , Spilsberg A. M.
Published: January 2009

A double‐blind comparison of the pain‐relieving effect of piroxicam 5 and 10 mg, acetylsalicylic acid 648 mg and placebo was performed in 120 patients with moderate to severe pain on the morning after orthopedic surgery. The changes in pain intensity and pain relief during the 8 h following medication were recorded by a trained nurse observer. 67 % of the placebo‐treated patients needed rescue drugs compared to 41% of the acetylsalicylic acid, 43% of the piroxicam 5 mg, and 45% of the piroxicam 10 mg treated patients. One to three hours after ingestion of the test drug, the piroxicam and the acetylsalicylic acid groups had significantly improved verbal rating pain intensity scores compared to placebo. In the overall assessment of pain relief at the end of the observation period, the patients' own assessment was significantly superior for acetylsalicylic acid and piroxicam 10 mg compared with placebo. In the observer's assessment of overall pain relief, placebo was significantly inferior to the three other groups. Thus piroxicam 5 mg and 10 mg give relief of pain after orthopedic surgery similar to that given by acetylsalicylic acid 648 mg. The pain‐relieving effect of these drugs can be distinguished from placebo, but not from each other. They are not potent enough when pain is moderate to severe after orthopedic surgery.