bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Comparative Study of Halothane and Enflurane in Paediatric Outpatient Anaesthesia
Authors: Davidson Sally H. 
Published: January 2009

Two groups of paediatric patients, consisting of 40 patients each, were studied with regard to anaesthesia induction and recovery. Group H was given halothane and Group E received enflurane. The induction time was similar for the two groups. Enflurane had, on average, a shorter recovery time (17±4 min) than halothane (26±4min) (P<0.05).The mean dose of anaesthetic given, expressed as the product of inspired concentration times minute ventilation, was 2.3±0.2 1 100% halothane and 2.8±0.2 1 100% enflurane. If one assumes that the minimum alveolar concentration (MAC) value for enflurane twice that of halothane, group E received a less potent anaesthetic dose. This might explain the similar induction times, and, in part, the shorter recovery time for enflurane in this study.No difference was noted between the two agents with regard to post‐operative nausea and vomiting or restlessness.
The Effects of Antihypertensive Medication on the Control of the Cardiovascular System during Halothane Anaesthesia in Rats
Authors: Kaukinen S. , Ylitalo P. 
Published: January 2009

The effects of hydralazine, clonidine, propranolol and methyldopa medication on the control of the circulatory system during halothane anaesthesia were studied in spontaneously hypertensive (SH) rats. Special attention was directed to the problem of circulatory emergencies. Under 1 and 3% halothane anaesthesia, the mean arterial pressure was lowest in methyldopa‐treated rats. During 3% anaesthesia, plasma renin activity was markedly increased in the methyldopa group and decreased in the propranolol group. Hydralazine medication suppressed the pressor responses to dopamine and metaraminol, whereas clonidine, propranolol and methyldopa increased the response to dopamine. These sympathetic agents induced more cardiac arrhythmias in SH controls than in normotensive ones. These arrhythmias were antagonized by hydralazine. The SH controls also tolerated haemorrhagic shock more poorly than did normotensive control rats. Among the pretreated animals, tolerance to this shock was highest in hydralazine‐and clonidine‐treated animals and lowest in the methyldopa group.The results suggest that during halothane anaesthesia SH rats are more prone to disturbances in the control of circulation than are normotensive controls. Hydralazine and, to a lesser extent, clonidine have a protective action against these disturbances, but the effect of methyldopa seems to be disadvantageous.
The Effect of Surgical Stress on Haemodynamics During Neurolept Anaesthesia
Authors: Santesson Joakim , Järnberg Per‐Olof , Arnér Staffan 
Published: January 2009

The influence of surgical stress on haemodynamics during neurolept anaesthesia (NLA) was studied in ten patients, while they were awake, under anaesthesia prior to surgery and peroperatively. Systemic arterial, pulmonary arterial, right atrial and pulmonary capillary wedge pressures, as well as cardiac output (Qt), arterial oxygen content and mixed venous oxygen content, were measured. Systemic and pulmonary vascular resistances, arterial‐venous oxygen content difference (AVD), oxygen consumption (vo2 and cardiac index (CI) were calculated.On institution of anaesthesia, CI fell from 2.8 ±.11 /min. m2 to 2.5±0.2 l /min.m2 and systolic arterial pressure (SBP) fell from 13.4±0.5 kPa to 10.2±0.3 kPa. During surgery CI rose to 3.3±0.1 1/min.m2 and SBP rose to 15.7±0.6 kPa. Prior to anaesthesia, AVD was 40.2±0.2 ml/l Under anaesthesia prior to surgery, AVD did not change, but vO2 declined from 207±13 ml/min to 171±10 ml/min. During surgery, AVD fell to 30.5±0.3 ml/l, while Vo2 remained unchanged.It is concluded that NLA has a direct metabolic depressant effect and, in association with surgery, is accompanied by hyperkinetic circulation.
Cardiovascular Effects of Local Adrenaline Infiltration During Neurolept Analgesia and Adrenergic Beta‐Receptor Blockade in Man
Authors: Pöntinen P. J. 
Published: January 2009

The adrenergic beta‐receptor blocking drug, alprenolol, was given together with atropine to 15 patients during neurolept analgesia (NLA) in order to prevent adrenaline‐induced cardiac arrhythmias. Four patients operated on without adrenergic beta‐receptor blockade formed the control group. Three of them developed tachyarrhythmias, ventricular tachycardia, multifocal ventricular extrasystoles and supraventricular tachycardia. All these arrhythmias were terminated by the adrenergic beta‐receptor blocking drug, propranolol. The fourth patient developed a temporary sinus tachycardia which did not require any treatment.The adrenergic beta‐receptor blockade induced a slight increase in pulse rate with almost no change in arterial blood pressure. The incidence of arrhythmias due to adrenaline infiltration was much less in this group. There was one supra‐ventricular tachycardia and scattered ventricular extrasystoles in two other patients.NLA alone does not protect the heart against adrenaline‐induced arrhythmias. It does, however, seem to be compatible with an adrenergic beta‐receptor blockade, which in turn provides partial protection against adrenaline‐induced arrhythmias. The occasionally developing arrhythmias can then be terminated with specific adrenergic beta blockers.
Effects of Ventilation with Large Tidal Volumes or Positive End‐Expiratory Pressure on Cardiorespiratory Function in Anesthetized Obese Patients
Authors: Eriksen Jørgn , Andersen Jens , Rasmussen Jens Peter , Sørensen Birgit 
Published: January 2009

The cardiorespiratory effects of ventilation with large tidal volumes (LTV) or positive end‐expiratory pressure (PEEP) were investigated in 10 extremely obese patients during anesthesia for a jejuno‐ileal by‐pass operation.Elevation of the tidal volume by 35% and insertion of a dead space (LTV‐group: five patients) or applying a PEEP of 1.0 kPa (PEEP‐group: five patients) resulted in significant rises in arterial oxygen tensions (Pao2) of 87.4% and 72.4%, respectively. The alveolar‐arterial oxygen tension differences (P(a‐a)o2) decreased by 29.2% in the LTV‐group and 25.6% in the PEEP‐group when compared to control values. No significant differences were found between the groups in Pao2 or P(A‐a)o2.PEEP‐ventilation caused a maximal increase in compliance of 42.6%, but there was an increase of only 20.8% in the LTV‐group.Stroke index (the impedance cardiography method) decreased by 19.7% in the PEEP‐group, whereas no changes occurred in the LTV‐group. The decrease in stroke index was probably due to a reduction in venous return, as reflected in the systolic time intervals. In the PEEP‐group a prolongation of the pre‐ejection period (PEP) was observed, causing an increase in the PEP/LVET‐ratio of 41.2%. A 13.8% increase in PEP/LVET‐ratio was found in the LTV‐group.In spite of the increased arterial oxygen contents, no improvements in arterial oxygen delivery were found in either of the groups.
Althesin®in Neurosurgical Patients: Effects on Cerebral Hernodynamics and Metabolism
Authors: Rasmussen Niels J. , Rosendal Tage , Overgaard Jørn 
Published: January 2009

The effect of althesin 0.5 ml/10 kg on arterial blood pressure, intracranial pressure, cerebral blood flow and oxygen uptake was studied on 19 occasions in 16 patients with varied cerebral pathology.Cerebral blood flow (CBF) was measured using the intracarotid 133xenon method and a 35‐channel scintillation detector after cannulation of the internal carotid artery, the internal jugular bulb and the lateral cerebral ventricle. Arterial and intracranial pressures were recorded continuously. Blood gas tensions were measured in simultaneously drawn samples from the internal carotid artery and the jugular bulb. Cerebral oxygen uptake was calculated from the product of CBF and arteriovenous oxygen content difference.Control values were obtained with the patients under a basic general anesthesia, consisting of N2O/O2 pancuronium. The effect of a bolus injection of althesin was then studied 1 and 20 min after the injection. A significant reduction in intracranial pressure, cerebral blood flow and metabolism at 1 min was found to have essentially subsided 20 min after the injection. In patients with focal brain damage, regional flow analysis revealed a paradoxical increase in flow after althesin in the areas corresponding to the focus.
Cerebral Autoregulation in Unconscious Patients with Brain Injury
Authors: Cold Georg Emil , Jensen Finn Taagehøj 
Published: January 2009

In 18 unconscious patients with traumatic brain injury, the cerebral autoregulation was tested during the first 2–3 weeks after the acute trauma. Regional cerebral blood flow (rCBF) was measured by the intra‐arterial 133xenon washout method before and after an increase of about 20% in the mean arterial blood pressure (MABP) by angiotensin. The difference between MABP and intraventricular pressure (IVP) was used as cerebral perfusion pressure (PP). Simultaneously, ventricular fluid pH, lactate and pyruvate were measured.Regional loss of autoregulation indicated by a 20% flow increase was observed in 29 out of 35 studies (83%), while hemispheric loss of autoregulation was observed in only one study. The results of the autoregulation tests were unrelated to the clinical outcome, the presence of brain‐stem lesion, and the ventricular fluid pH, lactate and lactate/pyruvate ratio. In repeated studies, a gradual normalization of the autoregulation was observed about 5 days after the acute trauma.
The Placental Transfer of Pancuronium and its Pharmacokinetics During Caesarian Section
Authors: Duvaldestin P. , Demetriou M. , Henzel D. , Desmonts J. M. 
Published: January 2009

The placental transfer of pancuronium and its pharmacokinetics were investigated in 33 pregnant women undergoing caesarean section. After a single intravenous injection of 60–100 μg/kg, the serum pancuronium concentration was measured (using a fluorimetric method) in serial samples of maternal blood and in umbilical arterial and venous blood obtained at the time of delivery. Detectable amounts of pancuronium were found in all foetal blood samples. The cord vein to maternal concentration ratio of pancuronium averaged 0.22; it increased significantly with prolongation of the induction‐delivery interval. The mean cord arterial to cord venous ratio of pancuronium was 0.66 (range 0.2–1.0), suggesting foetal drug uptake. Apgar scores were above 9 at 5 min in all cases, and there was no clinical evidence of any adverse effect in the newborns which could be related to the presence of a muscle relaxant.The distribution and elimination of pancuronium were compared in 18 normal subjects and in 21 women undergoing caesarean section. Plasma pancuronium concentration declined biexponentially with fast (α) and slow (β) phases, with half‐lives in the control group of 13 min and 146 min (mean values), respectively. In the women undergoing caesarean section, t 1/2 α was not changed, while t 1/2 β decreased slightly but significantly to 114 min.
Influence of Morphine Anaesthesia on the Endocrine‐Metabolic Response to Open‐Heart Surgery
Authors: Brandt M. R. , Korshin J. , Hansen A. Prange , Hummer L. , Madsen S. Nistrup , Rygg I. , Kehlet H. 
Published: January 2009

Twelve patients scheduled for aortic valve replacement during extracorporal circulation were randomly allocated to either morphine anaesthesia or fluroxene anaesthesia. Morphine in a total dose of 4 mg/kg was administered bcforc skin incision. At the start of extracorporal circulation all patients received 25 g glucose intravascularly. The endocrine‐metabolic response to surgery, as expressed by changes in plasma ACTH, cortisol, insulin, growth hormone, cyclic adenosine ‐3′, ‐5′‐monophosphate (cyclic AMP), glucose, free fatty acids, blood b‐hydroxy‐butyrate and cumulative nitrogen balance was measured before and during anaesthesia and surgery, and on the first five post‐operative days.It was found that morphine anaesthesia blocked the increase in ACTH, cortisol, growth hormone, cyclic AMP, and glucose during surgery. However, after initiation of extracorporal circulation only ACTH, cortisol, and, to a lesser degree, the glucose and insulin response to glucose were lowered by morphine anaesthesia. From the first to the fifth days after operation no differences between the two groups could be demonstrated in any parameter. Cumulative nitrogen balance was similar in the two groups.It is concluded that morphine in large doses administered bcfore skin incision inhibits the initial endocrine‐metabolic response to open‐heart surgery, but that the effect is short‐lasting and without effect on overall postoperative prokin catabolism.
Arrhythmias During Halothane Anesthesia. III.: The Influence of Barbiturates
Authors: Andersen J. R. , Eikard B. 
Published: January 2009

The effect of barbiturates on cardiac rate and rhythm during halothane ancsthesia without intubation was studied in a triple‐blind, randomized trial with 28 patients. The test group was premedicated with pentobarbital and induced with thiopental, while the control group was anesthetized with halothane and nitrous oxide only.There was a significant preponderance of sinus‐bradycardia and supraventricular disturbances in the control group.It is concluded that the use of barbiturates is advantageous because of their ability to suppress enhanced vagal tone.
Serum Cholinesterase Variants in the Danish Population
Authors: Hanel H. K. , Viby‐Mogensen J. , de Muckadell O. B. Schaffalitzky 
Published: January 2009

A total of 1278 adult patients were screened for serum cholinesterase (E.C. 3.1.1.8) variants. The following inhibitors were used for phenotyping of variants: dibucaine, fluoride, chloride, and urea.The observed incidence of cholinesterase variants in the Danish population was similar to that found in other European countries.
In VivoLung Uptake of Lidocaine in Pigs
Authors: Bertler ÅKe , Lewis David H. , Löfström J. Bertil , Post Claes 
Published: January 2009

A mixture of14C‐labelled lidocaine and indocyanine green dye (IG) (Cardiogreen®) was injected as a bolus into the pulmonary artery in pigs (15–25 kg). Time‐concentration curves for both substances were constructed from 2/s blood samples taken from the common carotid artery for approximately 20 s. The extraction of lidocaine in each sample and the 95% first passage uptake (FPU) were calculated, assuming that IG is inert with respect to the lung and that it remains within the vascular compartment. The IG curves were also used to calculate cardiac output. The acid‐base status and arterial blood pressure or ECG were also followed. Earli animal was given two injections.When 0.5 mg/kg b.w. lidocaine was injected, FPU was 41±3%; at a dose of 2 mg/kg b.w., FPU was 28±3% (P<0.05). The initial extraction during the first 2 s after appearance of the substances was approximately 80%. This level declined with subsequent samples, and the decline was equally rapid at both dose levels.
Hypoxia‐induced Pulmonary Vasoconstriction in Man: Inhibition due to Diethyl Ether and Halothane Anesthesia
Authors: Bjertnæs L. J. 
Published: January 2009

Impaired pulmonary gas exchange resulting in arterial hypoxemia is frequently observed in patients during general anesthesia. Recent animal investigations have revealed that pulmonary hypoxia‐induced vasoconstriction (a local mechanism which redistributes pulmonary blood flow from poorly to more amply ventilated regions) is abolished by commonly used inhalation anesthetics. Injectable anesthetics do not have this effect.The present work was undertaken to study whether pulmonary vasoconstriction in response to ventilation hypoxia could be elicted in man during intravenous anesthesia, and to find out whether any response thus obtained is reduced by diethyl ether and halothane. Under intravenous anesthesia, unilateral hypoxia (UH) was induced in two groups of young men by ventilating one lung, the test lung, with N2 and the other with O2. In both groups the time period of UH was subdivided into two sequences, one sequence with and one without inhalation anesthesia. In 10 subjects (group A), inhalation anesthesia was administered during the second sequence, and in 7 subjects (group B), inhalation anesthesia was given during the first sequence. The blood flow distribution (BFD) to the test lung during air breathing and following each of the two sequences of UH was determined by lung scintigraphy. The median test lung BFD in group A decreased from 49% (range 40–45%) of total pulmonary blood flow to 24.5% (range 19–32%) during UH. By superimposing ipsilateral inhalation anesthesia, it increased to 34% (range 27–48%). The increase was significant both for the diethyl ether and halothane subgroups. BFD to the test lung during the first period of UH was significantly higher during diethyl ether or halothane administration (group B) than during administration of intravenous anesthesia only (group A). The damping effect of inhalation anesthetics on the response to hypoxia was demonstrated at blood concentrations comparable to those used in clinical anesthesia. It is therefore likely that inhibition of hypoxia‐induced pulmonary vasoconstriction contributes to the development of arterial hypoxemia during diethyl ether and halothane anesthesia in man.
Longitudinal Spread of Intraneurally Injected Local Anesthetics: An Experimental Study of the Initial Neural Distribution Following Intraneural Injections
Authors: Selander D. , Sjöstrand J. 
Published: January 2009

Unexpected spinal anesthesia, occurring after peripheral nerve blocks close to the spine, may be caused by a centripetal spread of the local anesthetic along the injected nerve to the spinal cord. In order to analyze the pathway of such a spread, a radioactive local anesthetic mixed with a fluorescent dye was injected into different compartments of the rabbit sciatic nerve, and the early distribution of these tracers was studied by scintillation counting and fluorescence microscopy. Epineurial (extrafascicular) injections were of low injection pressure (25–60 mmHg) (3.3–7.9 kPa) and limited spread, while endoneurial (intrafascicular) injections reached higher pressures (300–750 mmHg) (39.9–99.7 kPa) and caused a rapid spread over long distances within the fascicle. The sacral plexus seemed difficult to pass. However, 20% of endoneurial injections reached the spinal cord, where the injectate primarily spread in the thin subpial space.Our experimental findings suggest that intraneural injections of local anesthetics are responsible for the reported cases of unexpected spinal anesthesia due to inadvertent intrafascicular spread. Although intrafascicular injections are rarely made, we recommend that intraneural injections of local anesthetics or other solutions close to the spine should be avoided, as they may cause unexpected spinal anesthesia or lesion of the cord.
Transcutaneous Oxygen Tension Measurement II. The Influence of Halothane and Hypotension
Authors: Gøthgen I. , Jacobsen E. 
Published: January 2009

The influence of halothane‐oxygen mixtures on three different transcutaneous oxygen electrodes was investigated. The influence of hypotension caused by halothane and halothane‐nitroprusside on transcutaneous oxygen tension measurement (tcPo2) in halothane‐anaesthetized patients was examined as well. The electrodes differed with respect to polarization voltages (630 mV or 500 mV) and electrolyte composition (silver chloride or silver bromide).A change dependent on halothane concentration was demonstrated in the electrode readings, both with a polarization voltage of 630 mV and with silver bromide as electrolyte. Using an electrode with 500 mV in polarization voltage and silver chloride as electrolyte, no changes were observed in the readings.During induced hypotension, the tcPo2 values fell in proportion to the mean arterial blood pressure. In patients with a mean arterial blood pressure over 11 kPa a tcPo2 /tcPo2 ratio of 0.6 was found.It is concluded that tcPo2 monitoring during halothane anaesthesia can be influenced in at least two ways, apart from changes in tcPo2: (1) by oxygen electrode error due to the halothane; and (2) by changes in skin blood flow.In comparison to the changes in tcPo2 due to the haemodynamic effects of halothane anaesthesia, the changes due to halothane error are small.
Halothane Anaesthesia and Suxamethonium III. Atropine 30 s Before a Second Dose of Suxamethonium During Inhalation Anaesthesia: Effects and Side‐Effects
Authors: Brandt M. R. , Viby‐Mogensen J. 
Published: January 2009

The protection against bradycardia afforded by atropine given intravenously just prior to a second dose of suxamethonium during halothane inhalation anaesthesia was studied in 100 healthy, adult patients randomly allocated to one of five groups characterized by dosage of atropine.ECG monitoring was continuous, and regular determinations were made of serum potassium, Po2, Po2 and blood pressure.Slowing of the heart rate was seen in more than 50% of patients in each group, but bradycardia (heart rate < 60 beats/min) was seen only in patients receiving the lowest dose of atropine—0.0075 mg/kg. In the other four groups (atropine 0.01 mg/kg‐0.02 mg/kg), bradycardia prophylaxis was effective, but at the cost of serious ventricular arrhythmias in 15% of the patients. The incidence of these arrhythmias seemed to increase with increasing atropine dosage. Marked tachycardia was also seen.Because of the incidence of side effects in this and other studies, no absolute recommendation can be made about suxamethonium bradycardia prophylaxis during halothane inhalation anaesthesia, but our present experience suggests that atropine in a dose not exceeding 0.01 mg/kg, given 30 s prior to a second dose of suxamethonium is best.
Theoretical Considerations on the Potential Hazards of Hyperventilation During Anaesthesia
Authors: Sørensen S. C. 
Published: January 2009

The purpose of this paper is to evaluate the effect of hypcrventilation on cercbral oxygenation. The best estimate of cerebral oxygenation is cerebral venous Po2 (Pvo2). Pvo2 has been considered in relation to Paco2 during nornioxaemia. In order to compare the effects of hyperventilation with the effects of hypoxaemia, Pvo2 has also been considered in relation to Pao2, when Pavco2 is constant. The results indicate that the low Pavco2 values which may be seen in the oprrating room with manual ventilation have the same effect on cerebral oxygenation as severe hypoxaemia.It is emphasized that the brain is better protected against threats to cerebral oxygenation, e.g. hypotension, if Pvco2 is kept close to normal during anaesthesia. During neurosurgical anaesthesia the advantages of excessive hyperventilation must be weighed against the threat it poses to oxygenation in healthy arras of the brain.
Transcutaneous Oxygen Tension Measurement I. Age Variation and Reproducibility
Authors: Gøthgen I. , Jcobsen E. 
Published: January 2009

In 20 patients, aged 19–80 y and without pulmonary or cardiovascular disease, transcutaneous oxygen tension (tcPo2) and arterial oxygen tension (Pao2) were measured. tcPo2 was measured with a Radiometer®TCM‐I (transcutaneous oxygen monitor) at 43 C°.The age regression for tcPo2 was: tcPo2 = 10.4–0.035 × age (r = 0.406); the corresponding equation for Po2 was: 13.8–0.053 × age (r = 0.687). The mean difference between tcPo2 and Pao2 was 2.6 kPa (s.d. = 0.97) and the ratio tcPo2/ Pao2 was 0.8.The accuracy of tcPo2 at the level 5.3–13.2 kPa based on 480 measurements was on the averagef 1.28 kPa (maximum ± 1.73 kPa) at the 95% confidence level.The accuracy of tcPo2 measurements is acceptable for clinical use, and in healthy adults tcPo, reflects Pao2.