bluuebunny/crossref_metadata_2025 huggingface dataset:
Pulmonary Hemodynamics During Direct Diagnostic Laryngoscopy
Authors: Sørensen C. Hjort , Sørensen M. Bredgaard , Jacobsen E.
Published: January 2009

Acute changes in systemic and pulmonary hemodynamics, together with blood gas changes, were recorded during diagnostic laryngoscopy for biopsy. Laryngoscopy was performed under general anesthesia, and two groups of patients were studied, one was ventilated intermittently, the other had controlied ventilation through an endotracheal tube. Paco2 rose in both groups, but only in the intermittently ventilated patients did the Paco2 values increase above normal levels. No significant difference in cardiovascular response was found between the two groups. Significant changes were: increases in mean arterial pressure, pulmonary arterial mean pressure, pulmonary capillary wedge pressure and central venous pressure. The increases reached a maximum during the laryngoscopic procedure and returned towards control values when the laryngoscope was removed. Systemic and pulmonary vascular resistance remained unchanged. The rises in Paco2 and sympathetic stimulation are believed to be the main causes for the observed hemodynamic changes.
Prediction of the Physiological Dead Space /Tidal Volume Ratio during Anaesthesia/IPPV from Simple Pre‐operative Tests
Authors: Fletcher R. , Jonson B.
Published: January 2009

It can be shown that the assumption of an arbitrary value for VDphys/VT during IPPV can lead to unacceptable degrees of hypo‐ or hyperventilation. We investigated 33 adult patients scheduled for major non‐thoracic surgery, to see if any simple tests could be used to predict VDphys/VT during anaesthesia/IPPV. Fifteen were smokers and 18 non‐ or ex‐smokers. The tests were spirometry, and the single breath tests for CO2 and for N2 (SBT‐CO2: SBT‐N2). Patients were ventilated during anaesthesia with a Servo Ventilator 900 B, and SBT‐CO2 was recorded from a CO2 Analyzer 930. During anaesthesia/IPPV, smokers had significantly greater VDphys/VT (0.40±0.10 vs. 0.31 ±0.07 [P<0.01]), and they had more steeply sloping phase IIIs of SBT‐CO2 (P<0.01) than non‐ and ex‐smokers. For smokers, VDphys/VT was correlated to age (r = 0.75, P<0.01), to the slope of phase III of both SBT‐CO2 and SBT‐N2, and to the ratio of FEV% to its predicted value. For non‐ and ex‐smokers, only one variable, efficiency, describing the shape of SBT‐CO2, was correlated to VDphys/VT (r = 0.53, P<0.05). Pre‐operative prediction of VDphys/VT based on age, smoking history, and SBT‐CO2 can reduce the uncertainty in estimating VDphys/VT and therefore ventilatory requirements. It appears to offer the greatest benefits amongst smokers, who show a large variation in VDphys/VT.
Admixture of Atmospheric Air in the T‐piece Used as a Weaning System
Authors: Hartmann‐Andersen F. , Andersen P. K. , Olsen J. E.
Published: January 2009

Ayre's T‐piece may be used for intubated, non‐anaesthetized patients requiring an oxygen supplement or humidified gas mixtures. The system has the disadvantage that atmospheric air (VAD) enters through the expiratory leg when the inspiratory How and therapeutic gas flow (TGF) are not equal. This admixture can be reduced in the simple T‐piece by the addition of either a compliant inspiratory reservoir, or a compliant inspiratory reservoir and an expiratory unidirectional valve. These three systems have been studied in a model investigation using different tidal volumes (VT), respiratory frequencies, and therapeutic gas flows. VAD was measured using a pneumotachograph and the inspiratory tidal volume was measured with a Wright Respiratory Monitor. The ratio VAD/VT was employed as an expression of the admixture of atmospheric air during inspiration. The introduction of a compliant inspiratory reservoir to the simple T‐piece results under all conditions in a considerable reduction in VAD/VT. A further reduction was obtained by introducing an expiratory unidirectional valve into the system ‐ however, with the result that the previously open system is turned into a closed system. When selecting a weaning system, the risk to the patient of the discontinuation of the gas flow should therefore be weighed against the advantages obtained by a reduction of the admixture.
Interscalene Brachial Plexus Block: Area of Analgesia, Complications and Blood Concentrations of Local Anesthetics
Authors: Vester‐Andersex T. , Christiansen C. , Hansen A. , Sørensen M. , Meisler C.
Published: January 2009

In a prospective clinical study including 100 patients, the consequences of using the interscalene approach to block the brachial plexus were investigated according to the area of analgesia, complications and blood concentrations of local anesthetics. Sufficient analgesia of the shoulder and the upper part of the arm was obtained in 98–99% of the cases, whilst the area of analgesia in the forearm and the hand was more variable. In two groups, with 10 patients in each group, the blood concentration was measured during the first 50 mill after injection in the neurovascular sheath by either the interscalene or the axillary approach. The peak values were at the same level in the two groups, but there was a much more rapid rise in concentration in the interscalene group. No toxic reactions were seen. The complications were in accordance with those reported in other publications.
Placental Transfer and Pharmacokinetics of Atropine after a Single Maternal Intravenous and Intramuscular Administration
Authors: Kanto J. , Virtanen R. , Iisalo E. , Mäenpää K. , Liukko P.
Published: January 2009

The placental transfer and pharmacokinetics of atropine were studied in 44 healthy parturients undergoing caesarean section. The concentrations in the plasma were determined by a new radioimmunoassay after intravenous (n = 32) or after intramuscular (n = 12) administration of 0.01 mg/kg of atropine. A fast placental transfer with apparent foetal uptake of the drug was found after intravenous injection. There was also a difference in the umbilical vein and artery concentrations after intramuscular administration. The maternal pharmacokinetics of i.v. atropine obeyed a two‐compartment open model with a fast distribution phase (mean tα1/2 = 1.02 min) and quite fast elimination (t1/2 = 2.56 h). The total apparent volume of distribution was 1.0 1/kg and the total plasma clearance 6.36 ml/min/kg. The mean peak maternal plasma levels after i.m. atropine administration were found at 1.59 h and the mean calculated half‐life of elimination was then 2.1 h. No atropine was found in the amniotic fluid.
Sister Chromatid Exchanges in Lymphocytes after Anaesthesia with Halothane or Enflurane
Authors: Husum B. , Wulf H. C. , Niebuhr E.
Published: January 2009

The potential mutagenicity of inhalation anaesthetics was investigated by the sister chromatid exchange (SCE) test system applied to lymphocytes in peripheral blood drawn from patients before and after anaesthesia. Twenty‐one women, aged 39–82 years (median 57.7 years) received halothane for 75–180 min (median 125 min). Fourteen other patients, aged 45–90 years (median 67.5 years) received enflurane for 90–180 min (median 130 min). In both groups the numbers of SCEs were unchanged immediately following anaesthesia and 5 days after. It was concluded that, by this method, comprising human cells exposed in vivo, there was no indication of a mutagenic effect of short‐term exposure to halothane or enflurane in anaesthetic concentrations.
Albumin Treatment Following Major Surgery
Authors: Zetterström H. , Hedstrand U.
Published: January 2009

The effect of a 20 % albumin solution on plasma oncotic pressure, renal function and peripheral oedema was investigated in 30 adult patients undergoing elective major abdominal surgery. Half of them received an average of 173 g of albumin between the end of the operation and the 5th postoperative day, in accordance with a standardized scheme. Otherwise the same schedules for fluid therapy and blood replacement were followed in all patients. Postoperatively, serum albumin and plasma oncotic pressure were fairly normal in the albumin group, but decreased by 28 % and 24 % in the control group. The difference between the groups was statistically significant during the first week, but disappeared during the second week. Arm and thigh circumferences increased postoperatively to a similar extent in both groups. There were no apparent differences in circulatory variables, alveolo‐arterial oxygen tension difference, incidence of wound infection or postoperative restoration of intestinal activity between the groups. Although renal and thromboembolic complications occurred only in the control group, the material is too small to permit any conclusions to be drawn from the possible difference in renal function and morbidity between the groups. The limited availability and high cost of albumin require strict indications for its use. Our results so far have failed to justify routine administration of concentrated albumin postoperatively.
Influence of Epidural Analgesia on Postoperative Changes in Various Serum Enzyme Patterns and Serum Bilirubin
Authors: Rem J. , Møller I. W. , Brandt M. R. , Kehlet H.
Published: January 2009

Postoperative changes in serum bilirubin, various serum enzymes (alanine‐amino transferase (ALAT), alkaline phosphatase (AP), lactate‐dehydrogenase (LDH), and creatine‐phosphokinase (CPK)), plasma glucose and cortisol were studied in 20 healthy, premenopausal women undergoing elective abdominal hysterectomy under either general anaesthesia with halothane or epidural analgesia (T4‐S5). Surgery under general anaesthesia was followed by increased levels of bilirubin, LDH, CPK, glucose and cortisol, whereas AP and ALAT were unaffected by surgery. Epidural analgesia inhibited increases in LDH, CPK, glucose and cortisol (P< 0.05), but not the increase in bilirubin. The results indicate that afferent neurogenic stimuli from the surgical area are important in mediating the postoperative changes in LDH and CPK, whereas factors other than neurogenic stimuli or adrenal hormones are responsible for the postoperative changes in bilirubin.
Influence on Cerebral Blood Flow of Infusion of Sodium Bicarbonate during Respiratory Acidosis and Alkalosis in the Dog
Authors: Arvidsson S. , Häggendal E. , Winsö I.
Published: January 2009

In anaesthetized dogs, a mixed acid‐base disturbance was induced by adding a pronounced metabolic alkalosis to an established respiratory acidosis or alkalosis. Cerebral blood flow (CBF) was measured by the radioisotope washout method. In the hypocapnic dogs, the addition of metabolic alkalosis did not significantly change cerebral blood flow. In the hypercapnic dogs, the intravenous infusion of alkali led to a substantial reduction of cerebral blood flow, parallelled by a reduction of cerebrovenous oxygen tension. Acid‐base analysis of cerebrospinal fluid (CSF) indicated an increased bicarbonate concentration. Hypercapnia is suggested to facilitate the passage of bicarbonate over the blood‐brain barrier, leading to cerebral vasoconstriction by means of increased extravascular pH.
Effects on Cerebral Blood Flow of Infusion of Hyperosmolar Saline During Cerebral Vasodilation in the Dog
Authors: Arvidsson S. , Häggendal E. , Winsö I.
Published: January 2009

In six anaesthetized dogs, cerebrovascular reaction to experimental hyperosmolality (plasma osmolality in the range of 350–400 mosm kg water‐1) induced by intravenous infusion of 0.6 M saline was studied. In order to provoke and reinforce any effects from saline passage over the blood‐brain barrier, pre‐experimental submaximal vasodilation was induced by means of hypercapnia and in some cases haemodilution. Cerebral blood flow (CBF) was measured by the radioactive gas elimination method. CBF was unaffected by progressive hyperosmolality during a 2‐h observation period.
Non‐Cardiogenic Pulmonary Oedema. A Serious Complication of Transurethral Prostatectomy. A Case Report
Authors: Reiz S. , Duchek M. , Kerkoff Y. , Olson B.
Published: January 2009

A patient undergoing prostatectomy under epidural analgesia developed clinical signs of a severe TURP syndrome. During resuscitation, it was revealed that serum sodium was only moderately decreased. Plasma oncotic pressure was, however, markedly decreased and the pressure gradient between plasma oncotic pressure and pulmonary capillary wedge pressure (approximately hydrostatic pressure) was 1 mmHg (0.13 kPa) only, allowing almost free filtration of fluid through the pulmonary capillary wall, resulting in a non‐cardiogenic pulmonary edema. The patient was successfully resuscitated with albumin and inotropic stimulation with prenalterol.
Fentanyl in the Fourth Cerebral Ventricle Causes Respiratory Depression in the Anesthetized but Not in the Awake Dog
Authors: Freye E. , Hartung E.
Published: January 2009

Specific binding sites for opiate‐induced bradycardia, hypotension and EEG‐synchronization are located in areas bordering the IVth cerebral ventricle in the dog. To see if the clinically observed opiate‐induced respiratory depression is mediated selectively from ponto‐bulbar respiratory neurones, increasing concentrations of fentanyl (2.5‐5‐10‐20 μg/ml) were perfused through the IVth cerebral ventricle in canines. Contrary to the awake state, fentanyl‐perfusion during halothane‐anesthesia (0.75 vol %/O2) induced a dose‐related increase in arterial Pco2. This effect was reversed by subsequent naloxone‐perfusion (20 μg/ml). The administration of halothane alone over the same period of time did not affect Pco2 in a similar manner. It is suggested that higher cortical centers which are involved in sensory awareness may modulate respiratory neurones in the medulla, since the depression of these higher centers by halothane resulted in opiate‐induced respiratory impairment. An additive effect of fentanyl‐ and halothane‐induced release of opiate‐like peptides (enkephalins) on respiration should also be considered.
Pharmacokinetics of Thiopental in Caesarian Section
Authors: Christensen J. Heslop , Andreasen F. , Jansen J. A.
Published: January 2009

Anaesthesia for a planned caesarian section in nine women was induced with an i.v. thiopental injection. The injection was stopped when the ciliary reflex disappeared. 250–300 mg was given over 60–85 seconds. The concentration of thiopental in peripheral venous blood 20 s after the disappearance of the ciliary reflex varied from 4.3 to 33.7 μg/ml. The simultaneously obtained concentrations at delivery (11–25 min after the start of the induction) were 1.7‐6.0 μg/ml in venous blood from the mothers and 1.3–5.5 μg/ml in cord vein blood. In two of the newborns, the Apgar scores were 8 and 9, in the other seven it was 10.

The baby with Apgar score 8 was delivered after 25 min and had a concentration in cord vein blood of 3.5 μg/ml. The decline in the concentration of thiopental in the venous blood of the mothers was described by a three‐compartment open model. The terminal half‐life was relatively short, between 91 and 595 min. The blood levels of thiopental in the newborns were followed for 22–33 h. The terminal half‐lives in the babies ranged from 616 to 2560 min.
Haemodynamic Changes Associated with Atropine/Neostigmine Administration: A Non‐invasive Investigation
Authors: D'Hollander A. A. , Dewachter B. , Deville A. , Vaisiere D.
Published: January 2009

Stroke volume, systolic time intervals and related index variations induced by atropine/neostigmine (AN) (0.75 mg/1 mg) decurarization mixture were investigated by non‐invasive methods (ECG, phonocardiogram, thoracic impedance) in 15 anaesthetized normocapnic patients in a stable state after induction of anaesthesia and prior to surgical stimulation. Data showed decrease in mean heart rate (HR) (initial value: 82 beats/min; after 10 min: 57 beats/min; P<0.001) accompanied by an increase in stroke volume (SV) (initial value: 75 ml, after 10 min: 100 ml; P<0.001). No alterations in myocardial contractility were noted with the systolic time intervals (PEP, PEP/LVET, 1 /PEP2). Under the conditions of the study, the negative chronotropic effect of AN mixture was not accompanied by a negative inotropic state.
Vascular and Metabolic Effects of Methylprednisolone and Phenoxybenzamine during Controlled Hypotension in the Dog
Authors: Haglund U. , Haljamäe H. , Hellman A. , Häggendal E. , Jennische E. , Lundberg D.
Published: January 2009

The relationship between central haemodynamics and vascular and metabolic parameters in skeletal muscle was studied in dogs subjected to controlled haemorrhagic hypotension and treated with cumulative doses of methylprednisolone (4–32 mg‐kg‐1), (or saline in the control group), followed by phenoxybenzamine. There were no significant haemodynamic or metabolic changes between the groups during the injections of steroid or saline. The alpha‐adrenergic receptor blockade caused, as found earlier, a pronounced vasodilation in the steroid group, which was parallelled by an increase in muscle blood flow in the same order of magnitude. There was no clearcut relationship between metabolic and vascular effects in the groups. Despite the significant difference in blood flow between the groups after phenoxybenzamine, only small and insignificant differences were seen in muscle metabolites, with the exception of muscle lactate which showed higher values in the steroid group. The study provides further evidence in support of the hypothesis that the haemodynamic effects of the combination of methylprednisolone and phenoxybenzamine are of neurogenic origin.
Effects of Prolonged Anesthesia with Enflurane or Halothane on Renal Function in Dogs
Authors: Wickström I. , Stefansson T.
Published: January 2009

Elevated serum inorganic fluoride levels (60–300 μmol/l), maintained over 6 h, influenced renal function in beagle dogs. Changes in water reabsorption were seen with an increased urine flow and free water clearance and decreased urinary concentration capacity. Possible nephrotoxicity as an effect of inorganic fluoride production during prolonged enflurane anesthesia was evaluated in a group of beagle dogs. Another group of dogs, anesthetized with halothane in equianesthetic doses, was studied for comparison. Serum inorganic fluoride levels and urinary oxalate excretion were determined and postanesthetic renal morphology was examined. Renal function was evaluated from endogenous clearances and concentration capacity before and after anesthesia. In the enflurane group, serum inorganic fluoride levels peaked at 22.5 μmol/1 at the end of anesthesia and decreased rapidly in the postanesthetic period. Urinary oxalate excretion did not increase. No changes in renal morphology were found. Renal function tests did not reveal any disturbance after enflurane anesthesia. The two anesthetized groups did not differ in any of the parameters studied, except in serum inorganic fluoride levels.
Hemodynamic and Cardiometabolic Effects of Prenalterol in Patients with Acute Myocardial Infarction and Shock
Authors: Reiz S. , Friedman A. , Haggmark S.
Published: January 2009

Five patients with acute myocardial infarction and shock were treated with a new, highly selective beta‐1‐adrenoreceptor agonist, prenalterol. After 1 and 2 mg of the drug, all patients had markedly increased blood pressure and cardiac output, but no changes in heart rate or systemic vascular resistance. Left‐ and right‐sided filling pressures decreased in three of the patients. In two of the patients, however, the increase in contractility and afterload was followed by a marked increase in left‐ and right‐sided filling pressures, and myocardial lactate uptake changed to lactate production. After addition of sodium nitroprusside, blood pressure and filling pressures returned towards normal, and myocardial lactate uptake was restored. As anticipated from the hemodynamic findings, myocardial oxygen consumption increased after prenalterol. It is suggested that the potent inotropic agent prenalterol may be used with great caution in cardiogenic shock.
Metabolic Ability and Enflurane Defluorination in Surgical Patients
Authors: Rosenberg P. H. , Oikkonen M. , Neuvonen P. J. , Leander P.
Published: January 2009

Antipyrine clearance and half‐life, which are measures of the hepatic metabolic ability, were determined prior to anaesthesia in 14 surgical patients. The antipyrine results correlated neither with the highest serum fluoride concentrations nor with the fluoride excretion in urine followingadministration of enflurane. Enzyme induction may therefore have little influence on enflurane metabolism in man. Inorganic fluoride concentrations in serum and in excreted urine were determined following the exposure of a total of 21 surgical patients to measured doses of enflurane. In the group of 14 patients tested for metabolic ability, a mean dose of 0.4 end‐tidal vol. %X h enflurane resulted in a mean peak serum fluoride concentration of 6.8 μmol/1 (maximum 13.6 μmol/l) 2 h after enflurane exposure. In the material as a whole, the enflurane dose was positively correlated with both post‐anaesthetic highest serum fluoride concentrations and the 24‐h fluoride excretion in urine. Furthermore, there was a correlation between the 24‐h post‐anaesthetic urine pH (P<0.01) as well as urine volume and fluoride excretion in urine during that time. At a urinary pH below 5.0, the fluoride excretion was very low, while the highest excretions were associated with a urinary pH of about 7.0.

Raising the patient's per‐ and post‐anaesthetic urine pH and maintaining a good urinary output (which also tends to increase urine pH) may be enough to prevent accumulation of inorganic fluoride in the body following enflurane anaesthesia.
Enflurane Anesthesia in Living Donor Renal Transplantation
Authors: Wickström I.
Published: January 2009

Two groups of patients undergoing elective living donor renal transplantation were studied during enflurane or halothane supplemented anesthesia. The duration of anesthesia was similar in both groups. The mean administered enflurane dose was 243 vol% min; the corresponding halothane dose was 56 vol% min. In the enflurane group, the mean serum inorganic fluoride level peaked at 21.0 μmol/1 3 h after the end of anesthesia. The inorganic fluoride level in urine produced by the renal graft increased continuously, but did not peak, during the first 24 postanesthetic hours.

The renal graft quickly started to function in all patients in both groups. The frequency of rejection reactions was higher in the enflurane group than in the halothane group. Serum creatinine levels decreased rapidly in both groups. Urine flow was high on the day of transplantation, but normalized on the first postanesthetic day. Renal sodium clearance decreased earlier in the enflurane group than in the halothane group. This difference was statistically significant on the first postanesthetic day. In the enflurane group, the required pancuronium dose was significantly lower than in the halothane group. In one patient in the enflurane group, the serum inorganic fluoride level increased to 37.5 μmol/1.

In this patient renal tubular function may have been affected, but the change was not conclusive since a pronounced rejection of the graft became evident. Since increases in serum inorganic fluoride level approaching 75% of the threshold level for nephrotoxicity in normal kidneys may occur, enflurane should not be routinely used in anesthesia for renal transplantation.
Disopyramide Anticholinergic Action
Authors: Byrne A. J. , Healy T. E. J. , Mahmoodi V. , Poole T. R.
Published: January 2009

The effect of disopyramide on cholinergic transmission has been studied using the frog isolated abdominis rectus preparation and the guinea pig isolated vas deferens hypogastric nerve preparation. Disopyramide (2 × 10‐5mol litre‐1) reduced the response of the abdominis rectus to carbachol (1.36 × 10‐6— 4.8 × 10‐5mol litre‐1). Furthermore, disopyramide (1 × 10‐6—3 × 10‐4mol litre‐1) produced a concentration‐dependent reduction in the response to carbachol (5.46 × 10‐6mol litre). The response to potassium chloride (3.34 × 10 mol litre‐1) was unaltered by disopyramide (1 × 10 —3 × 10‐4mol litre‐1). Disopyramide produced a dose‐related ganglionic blockade at concentrations greater than 2 × 10‐5mol litre‐1. Complete blockade to ganglionic transmission occurred at 3 × 10‐4mol litre‐1disopyramide.
Dose Response Studies in Elderly Patients Subjected to Epidural Analgesia
Authors: Andersen S. , Cold G. E.
Published: January 2009

In 51 men, aged 60–87 years, subjected to lumbar epidural analgesia for transurethral resection of the prostate gland, the relationship between doses of 10, 15 and 20 ml mepivacaine 1.5% with adrenaline 1:200,000 and the extension of analgesia was studied. Three different postures during application of epidural analgesia were investigated (left lateral position, sitting position with the patient turned supine immediately after injection, and the sitting position with the patient turned supine 5 min after injection). The results indicate that posture did not significantly influence the extension of analgesia, which was found to be positively correlated to the volume of mepivacaine, and the segmental dose requirement was positively correlated to the volume injected. It is concluded that transurethral resection of the prostate gland in patients over 60 years old can be performed using mepivacaine 1.5% with adrenaline 1:200,000 injected in the lumbar epidural space. In some cases, doses of 15 and 20 ml provoked an unwanted extension of analgesia, reaching the upper thoracic segments.
Central Haemodynamics and Oxygen Transport During CPAP With and Without Mandatory Ventilations
Authors: Vuori A. , Klossner J.
Published: January 2009

Ten patients, subjected 16 h earlier to open‐heart surgery (aortocoronary bypass and/or aortic valve replacement), were studied during the weaning period after postoperative mechanical ventilation. Central haemodynamics and oxygen transport were assessed along with total oxygen consumption during continuous positive airway pressure with four mandatory ventilations per minute (mode CPAP+IMV) and, subsequently, during CPAP alone.

During the two modes of ventilation, airway pressure was adjusted to be equal during the spontaneous inspiratory phases. All parameters of haemodynamics, oxygenation and oxygen consumption were found to be essentially satisfactory and unchanged during both modes of ventilation. Our observations suggest that, as the parameters studied were unaltered with the change from CPAP+IMV to CPAP, the use of ventilatory support for these patients during the weaning period (in the form of four mandatory ventilations per minute) appears, in terms of central haemodynamics and oxygen transport, to be well tolerated in cases where adequate spontaneous ventilation is in doubt.
Invasive Analysis of Non‐invasive Indicators of Myocardial Work and Ischaemia During Anaesthesia Soon After Myocardial Infarction
Authors: Reiz S. , Häggmark S. , ÖStman M.
Published: January 2009

Atrial pacing was used for preoperative evaluation of six patients with recent anterior myocardial infarction (MI) (e.g. within 6 weeks) scheduled for abdominal emergency surgery. Central and coronary haemodynamics were used to compare changes in myocardial work and oxygenation with alternations of the non‐invasive variables rate pressure product (RPP) (systolic blood pressure X heart rate), triple product (TP) (systolic blood pressure X heart rate X mean pulmonary arteriolar occlusion pressure) and ST‐T‐segments (lead V5).

There was good correlation between myocardial oxygen consumption and rate pressure product and triple product during pacing to stable angina pectoris. ST‐T‐segment depressions were recorded already at moderate chest discomfort and correlated well with a decrease in coronary vascular resistance. Changes in myocardial oxygen consumption induced by combined thoracic epidural analgesia (T3–4 to L1–2) and light general anaesthesia with nitrous oxide and fentanyl were poorly correlated with changes in rate pressure product or triple product. ST‐T‐segment depressions were recorded on five occasions in four of the patients, all in association with intubation and/or extubation. Only on one of these occasions could RPP or TP have indicated that myocardial oxygen demand exceeded supply. On the other four occasions, it was probable that myocardial ischaemia was induced by transient arterial hypoxaemia. The V5 ST‐T‐segment was the most sensitive non‐invasive variable to monitor. The anaesthetic method was safe in all patients, asjudged by good intraoperative cardiovascular stability, low morbidity and absence of intra‐ or postoperative reinfarction.
The Influence of Intramuscularly Administered Pethidine on the Amnesic Effects of Intravenous Diazepam during Intravenous Regional Anaesthesia
Authors: Korttila K. , Tarkkanen L. , Aittomäki J. , Hyöty P. , Auvinen J.
Published: January 2009

Patients undergoing surgery under regional anaesthesia often receive narcotic analgesics for premedication which may modify the sedative and amnesic effects of intravenously administered diazepam. Sixty‐two patients scheduled for upper extremity surgery under intravenous regional anaesthesia received 0.15 mg/kg of diazepam intravenously to supplement the local anaesthesia. Thirty‐two of the patients received 0.01 mg/kg of atropine plus 1 mg/kg of pethidine and 30 patients only atropine intramuscularly approximately 1 h before the injection of diazepam. Another 30 patients received the same atropine‐pethidine premedication and saline intravenously, and served as a reference group. Atropine‐pethidine premedication followed by saline did not produce any amnesic effects. Sixty‐nine and 38% of patients receiving atropine‐pethidine premedication followed by diazepam did not remember a picture shown to them 15 min after diazepam injection or the performance of operation, respectively, the respective figures for patients given atropine premedication followed by diazepam being only 23% and 0% (P<0.01 ‐ 0.001 between groups). The anti‐recall of painful stimulus (exanguination) was significantly (P<0.01) more common when diazepam was given after pethidine premedication (31%) when compared to its injection after atropine alone (7 %). The drowsiness produced by the drugs was greatest and the overall patient acceptability of the technique used most satisfactory when pethidine was used for premedication and diazepam for sedation. It is concluded that intramuscularly administered pethidine potentiates the amnesic action of intravenous diazepam for painful stimuli, prolongs the amnesic action of diazepam for visual stimuli and improves the patients' acceptability of intravenous regional anaesthesia supplemented by intravenous diazepam.
Cerebral Blood Flow in the Acute Phase after Head Injury
Authors: Cold G. E.
Published: January 2009

In 40 comatose patients with severe head injury, cerebral blood flow (CBF) studies were performed with the 133Xenon washout technique over the most severely injured hemisphere. All patients were mildly sedated with diazepam, chlorpromazine and meperidine and subjected to respiratory support. Simultaneously with the CBF study, intraventricular pressure (IVP), systemic arterial pressure (SAP) and ventricular fluid (VF) lactate, pyruvate and pH were measured. The results indicate a positive correlation between CBF and lactate in patients with a good recovery, irrespective of the time after the trauma, and a positive correlation irrespective of outcome, if the measurements were performed more than 3 days after the trauma. In patients with mainly supratentorial lesions without signs of brain‐stem lesions, CBF and CPP were positively correlated, while CBF and ICP were negatively correlated (lost autoregulation). In contradistinction, CBF was positively correlated to ICP and Paco2 in patients with diffuse brain injury. In some cases of repeated dynamic studies, the clinical course seemed to be related to changes in the measured parameters.
Control of Carbon Dioxide in Modified Mapleson A and D (Hafnia) Anaesthetic Systems. An Experimental Model
Authors: Andersen P. K.
Published: January 2009

The effects of varying ventilations (Ve) and fresh gas flows (FGF) on end‐expiratory CO2 (Feco2) levels were investigated in an experimental model lung, employing the Hafnia modification of the Mapleson A and D anaesthetic systems during CO2‐absorption and CO2‐wash‐out (rebreathing). Identical results were found in both systems: Feco2 was constant and independent of FGF with CO2‐absorption and constant Ve, whereas rebreathing resulted in increasing Feco2 levels as FGF was decreased. As control of Feco2 in the rebreathing systems by regulating FGF could only take place within Feco2 levels higher than that determined by Ve at complete CO2‐absorption, e. g. for the Hafnia A and D rebreathing systems, control of FGF necessitates relative hyperventilation. Feco2 with constant FGF decreased with increasing Ve during CO2‐absorption, as well as during rebreathing, although this decrease was less in the rebreathing systems. Thus a decrease in Feco2 with rising Ve can be avoided and hypocapnia prevented. The results agree with those obtained in clinical studies.
Pentobarbital‐Anesthetized and Decerebrate Cats Reveal Different Neurophysiological Responses in Anesthetic‐Induced Analgesia
Authors: Mori K. , Komatsu T. , Tomemori N. , Shingu K. , Urabe N. , Seo N. , Hatano Y.
Published: January 2009

Cats were used to assess the significance of differences in animal preparations in the study of anesthetic‐induced analgesia. Comparison was made between pentobarbital‐anesthetized and decerebrate non‐anesthetized cats. Bradykinin dissolved in normal saline was injected into the femoral artery as a noxious stimulus, and the neural response in the spinal cord lateral funiculus was recorded using the multi‐unit activity technique. The magnitude of the neural response and the changes in spontaneous firing were compared before and after cervical cord transection at C1. Before the transection, the response was greater in anesthetized than in decerebrate cats. The cord transection potentiated the response in both preparations, but the degree of potentiation was greater in decerebrate than in anesthetized cats.

These studies confirmed the presence of a descending pain inhibition system acting tonically on the nociceptive neural mechanisms in the spinal cord, and indicated the susceptibility of this system to pentobarbital. We conclude that pretreatment with pentobarbital induces pharmacologically a state of partial spinal cord transection and reduces the effects of drugs acting through supraspinal CNS structures.
Ventilation‐Perfusion Distribution During Inhalation Anaesthesia
Authors: Bindslev L. , Hedenstierna G. , Santesson J. , Gottlieb I. , Carvallhas A.
Published: January 2009

Ventilation‐perfusion (V̇a/Q̇) ratios were studied by means of an inert gas elimination technique in healthy subjects with an average age of 51 years in the supine posture (a) when awake, (b) during inhalational anaesthesia, spontaneously breathing, (c) during mechanical ventilation, and (d) when a positive end‐expiratory pressure (PEEP) was applied. In the awake subject a bimodal distribution of V̇A/Q̇ was recovered in most patients, one mode centered around the ratio of 1 and another, smaller mode, within low V̇A/Q̇‐regions. Any shunt was less than 3% of cardiac output. With anaesthesia and spontaneous breathing, the low V̇A/Q̇ mode was reduced and the shunt increased to an average of 6.2%. With mechanical ventilation, the major V̇A/Q̇ mode was widened while the shunt was further increased in 4 of 10 subjects (mean 8.6%). With PEEP, the shunt was reduced and a new mode within high V̇A/Q̇‐regions appeared. The shunt and low V̇A/Q̇‐regions may be explained in terms of airway closure while the high V̇A/Q̇ mode with PEEP may be attributed to the development of a zone I.
Caudal Block for Post‐Operative Pain Relief in Children after Genital Operations. A Comparison Between Bupivacaine and Morphine
Authors: Jensen B. H.
Published: January 2009

Twenty‐two children formed the basis for a controlled study of the effect and duration of the postoperatively applied caudal block on postoperative pain after genital operations. The purpose of the study was to compare the effect and duration of bupivacaine and morphine. Ten children (Group I, outpatients) underwent circumcision and 12 children (Group II, inpatients) underwent correction of hypospadias. The caudal block failed in one case. Outpatients were discharged after 4–5 h, and the caudal blocks with both bupivacaine and morphine were then still effective. In inpatients, the duration of pain relief was significantly longer using morphine (range 610–2195 min) than using bupivacaine (range 245–515 min). There were no complications of the caudal blocks.
Effects of Precurarization on the Blood Pressure and Heart Rate Changes Induced by Suxamethonium Facilitated Laryngoscopy and Intubation
Authors: Kautto U. M.
Published: January 2009

The effects of precurarization on blood pressure and heart rate increases during laryngoscopy and intubation were studied in 60 surgical patients, who were randomly allocated to four groups, receiving as a pretreatment d‐tubocurarine (0.05 mg/kg), alcuronium (0.03 mg/kg), pancuronium (0.008 mg/kg) or saline in a double‐blind fashion. d‐Tubocurarine and alcuronium pretreatments seemed to attenuate the blood pressure increase during laryngoscopy and intubation under suxamethonium. Moreover, d‐tubocurarine pretreatment protected effectively against high blood‐pressure increases. Heart‐rate increases were of the same magnitude in all the pretrealed groups. d‐Tubocurarine pretreat ment abolished suxamethonium‐induced fasciculations completely, whereas alcuronium pretreatment gave protection in 93% and pancuronium pretreatment in 43% of patients.
Effect of Two Levels of Induced Hypocapnia on Cerebral Autoregulation in the Acute Phase of Head Injury Coma
Authors: Cold G. E. , Christensen M. S. , Schmidt K.
Published: January 2009

In eight unconscious and artificially ventilated patients with severe head injury, cerebral autoregulation (CA) was tested during angiotensin infusion, before and after a reduction of PacO2. Intracranial pressure (ICP) and systemic arterial pressure (SAP) were continuously recorded. Regional cerebral blood flow (rCBF) was measured by the intracarotid Xe133 washout technique as initial slope index, stochastic and compartmental analysis. In contradistinction to previous human studies, we found a preserved CA during moderate hypocapnia (mean Paco2 34.2 mmHg) while the CA after a further decrease in Paco2 (mean value 23.1 mmHg) was lost. The apparently preserved CA may be a “false phenomenon” due to a regional increase in ICP. After a decrease in PaccJi, an association between high CO2 reactivity and rCBF increase during angiotensin was disclosed, while a decreased or unchanged rCBF was observed in regions with inverse steal or abolished CO2 reactivity. The study indicates that the interpretation of CA is facilitated by performing the test during two levels of Paco2, but the presence of impaired autoregulation in the acute phase of head injury indicates that deliberate increase in SAP may be dangerous, as it may provoke an increase of regional ICP and brain oedema.
A New Tracheostomy Tube
Authors: Lomholt N. , Borgeskov S. , Kirkby B.
Published: January 2009

Recent publications show that severe damage to the trachea is still a problem with high‐volume, low‐pressure cuffs. The NL tracheostomy tube was used in 85 patients for 3 days to 2 months (mean 16 days). This tube has a high‐volume, low‐pressure cuff with automatic regulation of the cuff pressure at 3kPa. The tube has a flexible tip. Fiberoptic examination at extubation showed minimal damage to the tracheal mucosa: 33 patients had normal mucosa and the rest had hyperaemia and/or fibrin formation. Four patients had ulcerations from suction catheters and four patients had small, superficial ulcerations produced by the tip of the lube. Of these last four patients, three had skin flaps that exerted pressure on the tube. Severe tracheal damage was prevented due to the combination of automatic regulation of cuff pressure and a flexible tip of the tube.
Comparison of Haemodynamic Effects of Pethicline and Anilericline in Anaesthetised Patients
Authors: Yrjölä H. , Heinonen J. , Tuominen M. , Heikkilä J.
Published: January 2009

Haemodynamic effects of equianalgesic doses of pethicline (1 mg kg‐1) and anilericline (0.25 mg kg‐1) were compared in patients with coronary artery disease, after induction of anaesthesia with flunitrazepam ‐ N2O ‐pancuronium. Contrary to previous finclings made in conscious patients, these analgesics produced a moderate circulatory depression. Heart rate, cardiac index and rate‐pressure product were decreased by both drugs, and anilericline alone decreased mean arterial pressure. The only statistically significant differences in the haemodynamic changes between the two groups were those in pulmonary capillary wedge pressure and rate‐pressure product, which were slightly lower after anilericline than after pethicline.
Close Scavenging of Anaesthetic Gases During Mask Anaesthesia
Authors: Nilsson K. , Sonander H. , Stenqvist O.
Published: January 2009

Experimental measurements have been performed of the air flow in front of scavenging orifices of various dimensions and at various evacuation flows. A design of a close scavenging system for clinical use is proposed. Prototypes of close scavenging systems have been used in adult and paediatric mask anaesthesia. Close scavenging considerably reduces the nitrous oxide concentration in the anaesthetist's breathing zone.
Expired Minute Volume Measurements During Anaesthesia Using Non‐Rebreathing Valves
Authors: Lindahl S. , Nordström L. , Olsson A. K.
Published: January 2009

Non‐rebreathing valves may cause leakage of anaesthetic gases from the inspiratory to the expiratory limb, leacling to errors in measurements of exhaled gas volume and gas composition. The fresh gas flow (FGF 1Xmin‐1) leakage (gas‐shunt) over a non‐rebreathing valve (AMBU Paedi Anaesthesia System) was experimentally investigated in a conscious volunteer. The gas‐shunt depended upon the tension within the breathing balloon, which is placed in the inspiratory limb. At low FGF's, i.e. with the breathing balloon close to collapse, no gas‐shunting was registered. At higher FGF's, a large gas‐shunt was found. Due to the negligible gas‐shunt found at low FGF settings, this AMBU system might be used for analyses and measurements of exhaled gases during Anaesthesia and spontaneous ventilation.
Effect of Fentanyl on the Gortisol and Hyperglycemic Response to Abdominal Surgery
Authors: Haxholdt O. St. , Kehlet H. , Dyrberg V.
Published: January 2009

Plasma cortisol and glucose were measured during upper abdominal surgery in 25 patients randomly allocated to groups receiving fentanyl doses of 10, 30 or 50 μg.kg‐1. The results showed that fentanyl 50 μg.kg‐1 abolished the cortisol response to surgery observed in patients receiving 10 or 30 μg.kg‐1. In contrast, the hyperglycemic response was uninfluenced by fentanyl at any dose.
A Comparison of Epidural Morphine and Epidural Bupivacaine for Postoperative Pain Relief
Authors: Modig J. , Paalzow L.
Published: January 2009

In 32 patients subjected to total hip replacement, postoperative pain relief was achieved by random treatment with either 5 mg of morphine in 10 ml of saline (n = 15) or 6–8 ml of 0.5% bupivacaine with epinephrine (n = 17), both drugs administered by the lumbar epidural route. In an additional group of 10 patients, post‐traumatic thoracic or post‐operative abdominal pain was relieved first by 4–6 ml of 0.5% bupivacaine with epinephrine and subsequently by 5 mg of morphine in 10 ml of saline, both drugs being administered by the thoracic epidural route. The duration of analgesia was significantly longer, on average, with morphine (28 h) than with bupivacaine (4.3 h) when the drugs were given by the lumbar route. Thoracic administration of morphine also resulted in a significantly longer duration of pain relief (on average 9.8 h) than that of bupivacaine (3.8 h). Morphine gave satisfactory pain relief in all cases. It was not associated with motor block, loss of sensitivity to temperature, touch, or pin‐prick, or any signs of sympathetic block, as was the case with epidural bupivacaine. Plasma concentrations of morphine were not detectable 8 h after injection, though the patients still had pain relief. One case of delayed severe respiratory depression occurred 6 h after morphine injection via the thoracic route. Epidural morphine analgesia should therefore be reserved for patients in whom continual surveillance is possible, at least until more is known about the pharmacokinetics of narcotics in the epidural and subarachnoid space.
Blood Glucose, Insulin, Antidiuretic Hormone and Renin Activity Response During Caesarean Section Performed Under General Anaesthesia or Epidural Analgesia
Authors: Kanto J. , Viinamäki O. , Grönroos M. , Lammintausta R. , Liukko P.
Published: January 2009

Glucose loacling caused a significant increase in insulin response (IRI) in patients undergoing caesarean section, both under general Anaesthesia and under epidural analgesia. After a fast intravenous glucose loacling given j ust before the administration of epidural bupivacaine, similar but more variable serum immunoreactive insulin levels were found as compared with those determined after a slower intravenous glucose infusion in patients under general anaesthesia. Plasma renin activity values did not change significantly in either group, but, differing from general anaesthesia, antidiuretic hormone levels (ADH) increased significantly in patients under epidural analgesia. The changes in IRI and ADH response may be caused by a higher psychic stress reaction of the conscious patients during caesarean section under epidural analgesia.
Systolic Time Intervals Measured by Pulsed Ultrasound‐Doppler
Authors: Lang‐Jensen T.
Published: January 2009

A new method for measuring systolic time intervals (STI) is presented. By using a pulsed ultrasound Doppler‐velocity‐meter, which is able to differentiate the velocity signals, it is possible to pick up signals just above the aortic valve. Combining the velocity signals and an ECG, the STI can be measured. The STI measured by this method were compared with STI measured by using a phonocardiograph. The results showed no significant difference.
Onset Time for Alcuronium and Pancuronium after Cremophor‐Containing Anaesthetics
Authors: Gramstad L. , Lilleaasen P. , Minsaas B.
Published: January 2009

Cremophor is a nonionic, surface‐acting agent, previously shown to bind to proteins and biological membranes. The compound is used as a solvent for certain anaesthetics. The effects of this surfactant on the onset times for alcuronium and pancuronium were investigated. Both artery‐to‐muscle (A‐M) and vein‐to‐muscle (V‐M) onset times were determined after cremophor‐ and non‐cremophor‐containing induction agents. Circulatory effects of the surfactant were investigated by measuring the blood velocity of the brachial artery using pulsed Doppler ultrasound. A significant reduction in both A‐M and V‐M onset times was found for pancuronium after cremophor‐containing anaesthetics. However, no difference was found for the onset times for alcuronium in the two induction groups. In contrast to alcuronium, there was no significant difference between A‐M and V‐M onset times for pancuronium. Arterial blood velocity was found to be practically the same after cremophor and non‐cremophor induction agents. The possibility of a stronger affinity of pancuronium than alcuronium to intravascular binding sites is suggested. Cremophor might, due to its protein and membrane effects, interfere with pancuronium association to these sites.