bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Ketamine Anaesthesia on the Content of Monoamines and their Metabolites in the Rat Brain
Authors: Ylitalo P. , Saarnivaara L. , Ahtee L.
Published: January 2009

The effects of ketamine anaesthesia (100 mg/kg i.p.) on the content of brain 5‐hydroxytryptamine (5HT), 5‐hydroxyindoleacetic acid (5HIAA), noradrenaline (NA), dopamine (DA) and homovanillic acid (HVA) were studied in male Wistar rats.

Fifteen min after ketamine injection, when the rats were deeply anaesthetized, the 5HT content in many brain regions tended to be increased. An opposite tendency was found in the brain 5HIAA content. In rats treated with probenecid, which markedly lengthened ketamine anaesthesia, the accumulation of SHIAA was significantly reduced by ketamine. In addition to ketamine anaesthesia, probenecid was found to lengthen thiopental anaesthesia. One hour after the ketamine administration, when the rats were no longer anaesthetized but were excited, the brain NA concentration was increased by 17% (P< 0.02). The brain DA content was unchanged, but at 15 min and 1 hour after ketamine administration the striatal HVA content was increased by about 55% (P< 0.05), suggesting an increased turnover of DA.

The results suggest that during recovery from ketamine anaesthesia the increased NA content and the increased DA turnover may be associated with the post‐anaesthetic excitement of the rat, whereas the decrease in brain 5HIAA content may coincide with the deepening of ketamine anaesthesia.
Diazepam in Emulsion Form for Intravenous Usage
Authors: VonDardel Otto , Mebius Claes , Mossberg Torsten
Published: January 2009

Since aqueous solutions of diazepam were introduced into clinical practice, the problem has arisen of local vascular side effects after intravenous injection. A new preparation of diazepam as a lipid emulsion is presented. It was prepared by Vitrum and shows many similarities to Intralipid®. A clinical trial was designed to study the incidence of pain in connection with the intravenous injection of diazepam and the incidence of subsequent thrombophlebitis. The preparation was used as a sedative to patients before gastroscopic investigation and as an inductor to general anaesthesia. In the material of 88 patients, thrombophlebitis was observed in 1.1%. Only 1 patient in the group of 314 patients studied complained of pain in connection with injection. The results observed were compared with previous investigations from the literature and with parallel control investigations. The new lipid emulsion form of the preparation was found to reduce significantly the incidence of local side effects involving the venous system. No significant difference in the therapeutic effect of the different preparative forms of the active substance was observed. The possible mechanisms involving the production of thrombophlebitis in connection with the injection of aqueous solutions of diazepam are discussed.
Misplacement and Loop Formation of Central Venous Catheters
Authors: Malatinsky J. , Kadlic T. , Mŕjek M. , Sŕmel M.
Published: January 2009

Exact placement is an essential prerequisite for long‐term use of a central venous catheter. Reported data show an extremely wide range of catheteral misplacements: from less than 1 % to more than 60%. Some approaches appear to be less advantageous than others, but the highest rates of misplacement occur in the cubital, external jugular and saphenous veins.

A series is presented of 378 radiographically controlled central venous catheters analysed for aberrant placement and loop formation. The total occurrence of faulty positioning and coiling reached 5.3%, while the respective incidences were 30:/, for the external jugular vein, 5.7% for the internal jugular vein, 5.5% for the infraclavicular technique of subclavian venepuncture, 5.3% for the innominate vein and 1.4% for the supraclavicularapproach of subclavian venepuncture. The total frequency for pure loop formation was 2.9%.

The authors discuss numerous reported data on catheter malpositioning, according to the specific techniques used, and compare them with their own results. The relatively low incideffce in the present series is possibly due to the high proportion of cases where the supraclavicular subclavian approach was used, the omission of the saphenousjfemoral andcubital techniques, and to pre‐determining the length of the inserted catheteral segments.
Breathing Mechanics, Dead Space and Gas Exchange in the Extremely Obese, Breathing Spontaneously and During Anaesthesia with Intermittent Positive Pressure Ventilation
Authors: Hedenstierna GöraN , Santesson Joakim
Published: January 2009

Breathing mechanics and gas exchange were studied in 10 extremely obese subjects (average weight 138 kg) prior to and during anaesthesia with mechanical ventilation. Breathing mechanics were analysed from measurements of transpulmonary pressure (during anaesthesia, trans‐chest wall pressure as well) inspiratory gas flow and tidal volume. Gas exchange was studied by analysing inspired and expired gas as well as arterial blood samples. The total dead space was deduced from the Bohr equation, and the division into anatomical and alveolar dead space was arrived at by capnography. The patients were anaesthetised with neurolept agents and ventilated with an air‐oxygen mixture. Lung compliance during spontaneous breathing was below normal and decreased further during artificial ventilation. Chest wall compliance measured during anaesthesia was within normal limits. Lung resistance was above normal during spontaneous breathing and increased further during mechanical ventilation. Total dead space was normal during spontaneous breathing and increased moderately during artificial ventilation, the increment coming mainly from alveolar dead space. A moderate hypoxaemia was recorded during spontaneous breathing, and the alveolar‐arterial oxygen tension difference was slightly elevated. During anaesthesia this difference was markedly greater. It is concluded that the most probable reason for the relative hypoxaemia is right‐to‐left shunting.
The Effect of Segmental Epidural Analgesia on Maternal and Foetal Acid‐base Balance, Lactate, Serum Potassium and Creatine Phosphokinase during Labour
Authors: Jouppila R. , Hollmén A.
Published: January 2009

Maternal and foetal acid‐base balance, Pao2, lactate, potassium and creatine phosphokinase (CPK) were studied during the course of 28 induced labours. Every second mother received segmental epidural analgesia during the first stage of labour (epidural group), while the remaining mothers (who were given pethidine for pain relief, if necessary) acted as a control group. In the epidural group the patients had only minimal changes in acid‐base balance and lactate concentration during the first stage. During the second stage lactate concentration increased. In the control group, on the other hand, the acid‐base balance showed signs of hyperventilation and lactic acid accumulation during the first stage. The potassium changes were quite minimal and were not significantly different between the groups. The CPK level did not change during labour, but 2 and 4 h after delivery it was significantly elevated in both groups. The foetal acid‐base balance, potassium, lactate and Pao2 values revealed no differences between the groups at any time. The CPK level in umbilical venous blood was significantly higher in the epidural group.
Hepatic Blood Flow and Cardiac Output During Fluoromar® Anaesthesia. An Animal Study
Authors: Juhl B. , Einer‐Jensen N.
Published: January 2009

Related values of cardiac output and hepatic blood flow were measured in eight premedicated (pethidine 10 mg/kg b.w.) dogs under varying depths of fluoromar® anaesthesia. The measurements were first taken under basis anaesthesia with barbiturate (mebumal natrium 25 mg/kg b.w.) gallamine (80 mg)‐N2O‐O2 (ratio 2 to 1) with controlled normoventilation, and then under increasing depths of fluoromar anaesthesia: increasing stepwise to l 1/2–3 and 6% inspiratory concentrations. Finally the measurements were repeated after the fluoromar had been discontinued. Using the basis anaesthesia as a reference, it was found that 6% fluoromar gave a reduction in cardiac output (34%), heart rate (11%) and mean pressure in the aorta (18%). The peripheral resistance was simultaneously increased by 22%. The effect on the splanchnic blood flow was far less and without significant changes from one step in the anaesthesia to the next. Using 6% fluoromar it was found that there was a maximum reduction in blood flow of 20% of the initial value. There was unchanged splanchnic resistance during the whole of the investigation.

After discontinuation of the fluoromar for 15 min and continued controlled ventilation (O2‐N2O), rising heart rate and blood pressure were observed; however, cardiac output and splanchnic blood flow were unchanged. Corresponding to this, an additional increase in peripheral resistance of 10% and an insignificant increase of 5% in the splanchnic resistance were observed.
Effect of Intermittent Positive Pressure Ventilation on Cardiac Systolic Time Intervals
Authors: Brundin Tomas , Hedenstierna Göran , McCarthy Graham
Published: January 2009

The measurement of systolic time intervals (STI) has been widely used as a non‐invasive method of assessing the inotropic state of the heart, and normal values are available for healthy individuals breathing spontaneously. The present study was performed in order to evaluate how intermittent positive pressure ventilation (IPPV) affects STI. Ten subjects were investigated before and during halothane anaesthesia for routine surgery. Oesophageal pressure, respiratory minute volume and frequency, arterial blood‐gas tensions, cardiac output and heart rate were also measured simultaneously.

As expected, the institution of IPPV was associated with a reduction in cardiac output and an increase in oesophageal pressure. Paco2 was reduced. These changes were associated with a considerable lengthening of electro‐mechanical systole. This was due to a lengthened pre‐ejection period (PEP), whereas the left ventricular ejection time (LVET) was slightly shortened. These changes were even more marked during artificial hyperventilation. The changes in STI are attributed mainly to the reduction of venous return to the heart, subsidiary factors being intrathoracic pressure, myocardial inotropy and vascular resistance.
Haemodynamic Effects of Massive Doses of Hydrocortisone and the Interaction with Phenoxybenzamine in Controlled Haemorrhagic Shock in the Dog
Authors: Häggendal E. , Lindfors Maria , Lundberg D.
Published: January 2009

Haemorrhagic shock was produced in anaesthetized dogs by bleeding into a blood reservoir system. The blood level of the reservoir was adjusted at a level above the heart, corresponding to a mean arterial blood pressure of 6.7 kPa (50 mm Hg). The dogs were treated with hydrocortisone and the adrenergic alpha‐receptor blocking agent phenoxybenzamine during the hypotension period. Hydrocortisone (80–160 mg kg‐1) was found to induce vasodilation, which, however, was of a very small magnitude and was of short duration. Phenoxybenzamine given after hydrocortisone caused very pronounced vasodilation. Hydrocortisone (80 mg kg‐1) given after phenoxybenzamine also showed a vasodilator activity, which seemed to be greater than that of the same dose of hydrocortisone given alone. Thus, the vasodilator action of hydrocortisone does not seem to be due to an alpha‐receptor blockade of the drug. The vasodilator action of phenoxybenzamine given after hydrocortisone was greater than that of even higher doses of the drug given alone. From the present findings and the fact that corticosteroids are known to potentiate the sympathomimetic action of catecholamines, it is suggested that the hydrocortisone‐induced potentiation of the vasodilation action of phenoxybenzamine found is related to an increased vascular adrenergic beta‐receptor tone.
Left Ventricular Ejection and the Heather Index Measured by Non‐Invasive Methods during Postural Changes in Man
Authors: Hill D. W. , Merrifield A. J.
Published: January 2009

Differences have been found, which are usually 1% or less, between the left ventricular ejectidn time measured from the external carotid pulse tracing, and from the rate of change of thoracic impedance (dZ/dt) waveform, using either the second heart sound or the X‐point of the dZ/dt tracing as the end‐point.

The Heather Index obtained from the ECG and dZ/dt tracings has been correlated with other indices of cardiac performance. The changes observed in the physiological variables during head‐up and head‐down tilting were in the expected directions.
Pressure and Volume Changes in Tracheal Tube Cuffs during Anaesthesia
Authors: Revenäs B. , Lindholm C.‐E.
Published: January 2009

Recently, it has been observed that, when a patient is breathing a nitrous oxide‐oxygen mixture and the cuff of the tracheal tube is filled with air, nitrous oxide may diffuse into the cuff and thereby cause an increase in volume and pressure. In the present investigation, different gas mixtures were used to fill the cuff, and repeated measurements of pressure, and occasionally of volume, were made during anaesthesia. Both large‐volume and small‐volume cuffs were studied. A considerable increase in volume and pressure took place in both types of cuffs. The changes were directly proportional to time for the first few hours. If the cuff was inflated with nitrous oxide‐oxygen, no pressure increase occurred, and this was also true for the air‐filled cuff if halothane anaesthesia was given.
Airway Closure and Distribution of Inspired Gas in the Extremely Obese, Breathing Spontaneously and During Anaesthesia with Intermittent Positive Pressure Ventilation
Authors: Hedenstierna GöraN , Santesson Joakim , Norlander Olof
Published: January 2009

Airway closure (closing capacity, CC), FRC, total efficiency of ventilation (lung clearance index, LCI) and distribution of inspired gas (nitrogen washout delay percentage, NWOD) were determined by nitrogen washout techniques and arterial Po2 and Pco2 measured by standard electrodes in 10 extremely obese subjects, prior to and during anaesthesia and artificial ventilation. CC was normal, but because of small FRC, airway closure occurred within a tidal breath in 9 out of 10 subjects during spontaneous breathing, when awake. Po2 was reduced, the hypoxaemia correlating to the magnitude of airway closure. LCI was normal, but NWOD was borderline. During anaesthesia, CC was unaltered but FRC was further reduced, so that in nine subjects airway closure occurred above FRC and tidal volume together. A marked increase in relative hypoxaemia was recorded. LCI and NWOD rose, indicating less efficient and less even ventilation. It is concluded that airway closure reasonably explains the marked hypoxaemia in obese subjects during anaesthesia, and that it may also be the reason for the uneven distribution of inspired gas.
Studies on Pulmonary Function in Patients during Respirator Treatment. Diagnostic and Prognostic Evaluations
Authors: Gertz >Ingrid , Hedenstierna Göran , Löfström Bertil
Published: January 2009

Twenty‐nine patients, divided into three groups: 1) chronic obstructive pulmonary disease; 2) acute or chronic pulmonary disease with left heart failure; 3) respiratory insufficiency after peritonitis, pancreatitis, and/or sepsis, were studied during respirator treatment with regard to gas exchange, breathing mechanics and central circulation. The dead space ventilation was somewhat greater in group 1 than in the other groups. The alveolar‐arterial oxygen tension difference was least in group 1, greater in group 2 and extremely high in group J. Neither dynamic compliance of the thorax nor inspiratory resistance showed any significant differences between the groups. The cardiac output had the highest values in group J. The venous admixture was generally small in group 1 and extremely large in group 3. The pulmonary artery pressures were highest in group 2. Three variables proved to be valuable when assessing the prognosis of a patient: a large venous admixture; a lagge alveolar‐arterial oxygen tension difference, and a high pulmonary artery pressure indicated a less favourable prognosis.
Uptake of Bupivacaine (Marcaine®) in Liver and Lung after Intramuscular Administration in the Dog
Authors: Irestedt Lars , Andreen Magna , Belfrage Patrick
Published: January 2009

The uptake of bupivacaine in the liver and lung of the dog was studied 10, 20, 30 and 60 min after intramuscular injection of the drug. It was possible to quantify this uptake by combining measurements of concentrations and flows. The administration of bupivacaine (0.75 mg/kg b.w.) did not result in any significant circulatory changes. Arterial bupivacaine concentrations showed major variations, indicating interindividual differences in absorption rate. Lung uptake after 10 min was high in two dogs with initially high blood concentrations of bupivacaine, but low after 20 min or longer. The other dogs showed little or no uptake. Mean hepatic bupivacaine uptake was about 50% of the total dose during the first hour after injection; this indicates the central role of the liver in eliminating bupivacaine even during the initial period following administration. The hepatic extraction ratio showed interindividual variations, but the mean value of about 55% was constant throughout the observation period. This is in agreement with earlier findings indicating a first‐order elimination of bupivacaine.
Suitability of Althesin® as a Short‐Acting Anaesthetic Agent
Authors: Kauste A.
Published: January 2009

The suitability of Althesin® as a short‐acting anaesthetic agent was studied by comparing it to methohexitone. Twenty‐eight anaesthesias were given using equipotent doses of the two anaesthetics in order to anaesthetize 14 patients once with each drug. Thus the patients served as their own controls. Sleep induced by Althesin averaged 7 minutes, which was slightly but not statistically significantly longer than that produced by methohexitone (average 6 minutes). The time taken until orientation of the patients was complete was considerably longer with Althesin than with methohexitone. The responses to Althesin had a much wider range of individual variation in induction time, duration of anaesthesia and orientation time. After Althesin, three patients displayed mental confusion with anxiety on awakening. The recovery from anaesthesia was assessed by several recovery tests and observations, in addition to the patients' subjective assessments. Drowsiness was more manifest and persisted longer following Althesin than after methohexitone. Ninety minutes after anaesthesia, a tendency to collapse on standing was obvious following methohexitone, but this was not seen after Althesin. The level of test values and the physical status of the patients returned to pre‐anaesthetic levels within 2 hours after both agents. The majority of the patients found anaesthesia with both compounds pleasant. However, they seemed to favour methohexitone as regards pleasantness and their subjective impression was of faster awakening or less postanaesthetic drowsiness.
Restoration of Oxygen Uptake and Blood Flow in the Rat Cerebral Cortex after Halothane Anaesthesia
Authors: Berntman Leif , Carlsson Christer , Siesjö Bbo K.
Published: January 2009

Halothane decreases both the certal blooi Row (CBF) and the cerebral metabolic rate for oxygen (CMRo2) when given in anaesthetic doses. A recent report (Gjedde & Hindfelt 1975) suggests that when halothane is administered to rats for 1 hour, CBF and CMRo2 are depressed by about 30 and 40%, respectively, for as long as 4 hours after discontinuation of the halothane anaesthesia. In the present study rats were anaesthetized with 1% halothane for 1 hour, and CBF and CMRo2 were measured at the end of a 30 min recovery period, during which 70% N2O was administered. Comparison with animals maintained on 70% N2O throughout the entire 90 min period showed that previous halothane anaesthesia had no effects on CBF or CMRo2.
Oxygen Transport and Venous Admixture in the Extremely Obese. Influence of Anaesthesia and Artificial Ventilation with and without Positive End‐Expiratory Pressure
Authors: Santesson Joakim
Published: January 2009

Eight extremely obese patients (mean weight 136 kg) were studied when awake and breathing air, and during anaesthesia with controlled ventilation (oxygen fraction in inspirate (Fio2): 0.5). During anaesthesia, the patients were first studied with zero end‐expiratory pressure (ZEEP) ventilation. Then two different positive end‐expiratory pressures (PEEP) were applied, 10 cmH2O and 15 cmH2O2 in order to study the effect of an increase in functional residual capacity (FRC). Arterial oxygenation and oxygen availability, as well as cardiac output (Qt) and venous admixture (Qs/Qt) were studied. With the institution of anaesthesia and ZEEP, the alveolar arterial oxygen tension difference (P(A‐a)o2) rose from 3.5 ± 1.1 to 28.4 ± 2.6 kPa, and the oxygen availability fell from 1346 ± 222 to 1039 ± 239 ml/min, due to the additive effect of an increase in Qs/Qt from 10 ± 4 to 21 ± 5% and a fall in QT, from 7.7 ± 1.2 to 5.5 ± 1.1 l/min. With increasing levels of PEEP, despite a fall in P(A‐a)o2, there was a reduction in oxygen availability. This was due to simultaneous reduction in Qs/Qt and QT. At a PEEP of 15cmH2O, the P(A‐a)o2 was 21.2 ± 7.1 kPa, oxygen availability 862 ± 170 ml/min, Qs/Qt 13 ± 4 and QT 4.4 ± 0.6 I. It is concluded that PEEP ventilation significantly reduces Qs/Qt in extremely obese patients during anaesthesia and should be used in these patients if there is arterial hypoxemia despite a high Fio2
A Transportable Ejector Flowmeter
Authors: Jørgensen S. , Thomsen A.
Published: January 2009

A transportable ejector flowmeter for the complete removal of anaesthetic gases from operating theatres and anaesthetic rooms is described. The ejector flowmeter can also be employed as a suction unit driven by compressed air.
The Dumping Valve and its Clinical Application
Authors: Jørgensen S. , Thomsen A.
Published: January 2009

An open reservoir for the collection and evacuation of anaesthetic gases permits leakage to room air. The use of a closed reservoir for the removal of overspill gas from anaesthetic circuits is described. Calibrated gas evacuation is carried out through an ejector flowmeter from the anaesthetic circuit or from a closed reservoir, where the gas is collected via a relief valve. In order to eliminate the risk of high or low pressure in the reservoir employed, a relief valve and a dumping valve is included in the system.

The dumping valve may also be a permanent fixture on the anaesthetic machine, placed at the outlet for anaesthetic gas mixture. If the admission of anaesthetic gas fails, then the patient will inhale room air.
The Haemodynamic Effects of Adrenergic Receptor Blockade or Stimulation During Nitrous Oxide Anaesthesia in Dogs
Authors: Dottori O. , Häggendal E. , Linder E. , Nordström G. , Seeman T.
Published: January 2009

The effects of ventilation with normoxic and hyperoxic nitrous oxide on systemic, pulmonary and coronary haemodynamics before and after adrenergic receptor blockade or stimulation were investigated in 15 dogs. To evaluate a blocking or stimulating effect of nitrous oxide on the α‐adrenergic receptors, the animals were given phenoxybenzamine or noradrenaline, respectively. The effects of β‐adrenergic receptor blockade or stimulation were studied after injection of pro‐pranolol or isoproterenol, respectively. The experiments showed that in spite of the lack of α‐receptor blocking properties and despite the tendency to produce β‐receptor blockade, nitrous oxide induced vasodilation. The findings of the present study, together with the increase in cardiac output and peripheral vasodilation, suggest that the cardiovascular effects of nitrous oxide are extra‐adrenergic.
The Haemodynamic Effects of Nitrous Oxide Anaesthesia on Myocardial Blood Flow in Dogs
Authors: Dottori O. , Häggendal E. , Linder E. , Nordström G. , Seeman T.
Published: January 2009

The effects of ventilation with nitrous oxide in oxygen on myocardial blood flow and oxygen metabolism were investigated in 31 mongrel dogs. The results of this study showed that, compared with controls, hyperoxic nitrous oxide mixtures did not cause any great changes in myocardial haemodynamics, despite a decrease in cardiac output and an increase in systemic vascular resistance.

Normoxic nitrous oxide mixtures produced an increase of the coronary blood flow due to decreased coronary vascular resistance. To what extent this coronary vasodilatation resulted from an increased myocardial metabolism or from a direct effect of nitrous oxide on the coronary vascular bed cannot be quantified from the present results.
The Haemodynamic Effects of Nitrous Oxide Anaesthesia on Systemic and Pulmonary Circulation in Dogs
Authors: Dottori O. , Häggendal E. , Linder E. , Nordström G. , Seeman T.
Published: January 2009

The haemodvnamic effects of nitrous oxide in normoxia (20% oxygen) and in hyperoxia (50% oxygen) were investigated in 13 dogs. Nitrous oxide in hyperoxia caused a significant rise in total peripheral resistance and a significant decrease in cardiac output, heart rate, myocardial contractility (dP/dt max) and cardiac worl?. On the other hand, nitrous oxide in normoxia seemed to reverse these findings and did not exert any negative inotropic effects on the myocardium. The results indicate that the earlier reported sympathetic activation of the circulation may be related to hyperoxia and not to nitrous oxide as such.
Muscle Tone under Fentanyl‐Nitrous Oxide Anaesthesia Measured with a Transducer Apparatus in Cholecystectomy Incisions
Authors: Askgaard Bengt , Nilsson Tove , Ibler Mladen , Jansen Erik , Hansen Jørgen Bech
Published: January 2009

Fentanyl is a strong, synthetic analgesic which may cause muscular rigidity when administered intravenously. To obtain a quantitative measure of the possible increase in muscle tone after intravenous fentanyl, the muscular tension of the right rectus abdominis was measured in 20 patients before and after administration of this drug.

A traction transducer apparatus was fastened between the anterior and posterior rectus sheath in a right oblique laparotomy incision. Premedication was with pentobarbitone, and the anaesthesia and muscle relaxation were effected by thiopentone or enibomal and nitrous oxide‐oxygen with 75% nitrous oxide, and suxamethonium infusion (0.2%) until the measurement of tension was started. Immediately after the action of suxamethonium had ceased, fentanyl, about 0.004 mg/kg body weight, was administered. An increase in tone was found in 15 cases (75%). The mean increase was 9.2 N. The influence of the anaesthesia upon the result is discussed, and it is concluded that fentanyl must be responsible for the increase in muscle tone.
The Need for Halothane Supplementation of N2 O‐O2‐Relaxant Anaesthesia in Chronic Alcoholics
Authors: Tammisto Tapani , Tigerstedt Irma
Published: January 2009

The demand for intermittent halothane supplementation during N2O‐O2‐relaxant anaesthesia was studied in 25 alcoholics (annual consumption over 15 1 pure alcohol) scheduled for biliary or gastric surgery. The controls were 45 nonalcoholics and 43 patients with an annual consumption of between 1 to 15 1. Thiopental (3 mg/kg/min) was given for induction. After intubation, halothane supplementation was given in 0.5% concentration for 10‐min periods. Standardized criteria for halothane supplementation were various motor and autonomic responses to painful stimuli. Muscular relaxation was kept fairly constant (roughly 90%), as assessed visually with the aid of a peripheral nerve stimulator. The total time for which halothane supplementation was given, expressed as a percentage of the total anaesthesia time, was used as an indication of the need for halothane supplementation. The need for thiopental for induction was not increased to a statistically significant extent in alcoholics, but signs of excitation did occur in 40% as compared with 11% in non‐alcoholics (P < 0.01). The demand for halothane supplementation was higher in alcoholics (47±4.8%, s.e. mean) than in non‐alcoholics (33±2.3%). This difference, however, was partly due to the higher incidence of gastric surgery, which required more supplementation than biliary surgery. Analysis of the different criteria indicating the need for halothane supplementation revealed that an increase in blood pressure or heart rate was more common in non‐alcoholics, whereas motor irritability, sweating and lacrimation were more frequent in alcoholics. Management of the anaesthetic posed no special difficulties in the alcoholics with an estimated mean annual consumption of 32 ± 4 (s.e. mean) litres of absolute alcohol. Three patients (5% of the alcohol consumers) reported dreams or recollections, suggesting that this mode of halothane supplementation does not guarantee an adequate anaesthetic depth. The difficulties and biases associated with this type of analysis are discussed.
The Relationship between Disposition and Duration of Action of a Congeneric Series of Steroidal Neuromuscular Blocking Agents
Authors: ÁGoston S. , Crul E. J. , Kersten U. W. , Houwertjes M. C. , Scaf A. H. J.
Published: January 2009

The renal and hepatic elimination and biotransformation, as well as the relation between disposition and duration of action of pancuronium and two of its analogues, dacuronium and ORG.6368, have been investigated in the cat. In pharmacokinetic studies, appreciable amounts of the latter two compounds were found in the urine, bile and liver 8 h after their intravenous administration. Various proportions of the injected dose of the respective drugs were metabolized. In another series of experiments it was shown that the early hepatic uptake (during the first 3 min after the injection) of ORG.6368 was significantly greater than that of dacuronium and pancuronium. The intensity and duration of action of the neuromuscular blocking effect of the three compounds were studied after intravenous and “close” intraarterial injection. On the basis of these pharmacokinetic and neuromuscular studies, it was concluded that the short duration of action of ORG.6368 is due primarily to its early hepatic uptake. The possibility cannot be excluded, however, that differences in the kinetics of the drug action of ORG.6368 and the other two compounds also contributed significantly to the differences seen in the duration of action of these compounds.
Ketamine and Diazepam as Anaesthesia for Forceps Delivery. A Comparative Study
Authors: Ellingson Arne , Haram Kjell , Sagen Norvald
Published: January 2009

In a clinically controlled trial in forceps delivery, a comparison was made between the general anaesthesia induced by ketamine and that by a combination of diazepam and N2O. Local anaesthesia was added in the diazepam group for episiotomy and suturation. The indication for operative delivery was in all cases a prolonged second stage of labour. In the ketamine group, awareness was noted in four cases out of 13, even if the analgesic effect was found to be good. Four patients showed marked, short‐lasting elevation of blood pressure and seven had unpleasant dreams. All thirteen mothers in the diazepam group found the anaesthesia effective and the recovery pleasant. The blood pressure was stable. One mother in each group required ventilation with oxygen due to respiratory depression of short duration.

Three of the children in the ketamine group and two in the diazepam group had subnormal Apgar score with slight acidosis. This was probably not attributable to the anaesthesia.
Transplacental Passage of Ketamine after Intravenous Administration
Authors: Ellingson Arne , Haram Kjell , And Norvald Sagen , Solheim Einar
Published: January 2009

This study was designed to measure how fast and at what concentrations ketamine would enter the foeto‐placental circulation, when administered intravenously to 10 healthy mothers immediately before forceps delivery, which was indicated by a delayed second stage of labour. It is shown that ketamine very rapidly passes the placenta, and that ketamine levels in cord blood exceed the levels in the maternal venous blood as early as 1 min 37 s after the injection. The ketamine levels in cord blood reach a maximum in the period 1 min 37 s to 2 min 5 s after the injection. Later they show a tendency to decline. A short‐lasting, marked elevation of blood pressure was produced by the ketamine anaesthesia. Two of the newborn showed low Apgar scores at 1 min. In one of them this was probably attributable to the anaesthesia.
Central Venous Cannulation: A Radiological Determination of Catheter Positions and Immediate Intrathoracic Complications
Authors: Fischer J. , Lundström J. , Ottander H.‐G.
Published: January 2009

The incidence of immediate complications on inserting central venous catheters into 475 patients is reported. The catheter positions were verified by X‐ray. Six different insertion routes were used. Central venous cannulation via the right internal jugular vein is recommended because of the high incidence of satisfactory catheter positions and the small number of puncture complications with this route.
Respiration, Circulation and Anaesthetic Management in Obesity. Investigation before and after Jejunoileal Bypass
Authors: Söderberg Margareta , Thomson Dick , White Thomas
Published: January 2009

Some ventilatory and circulatory parameters were studied in 17 very obese patients before and after weight reduction following jejunoileal bypass. A low vital capacity and signs of impaired lung function with intrapulmonary shunting, increased alveolar‐arterial Po2 difference and low Pao2 were found. Although the spirometric values improved significantly after weight reduction, the ventilatory disturbance persisted. A normal response to inhalation of CO2 was seen. The total blood volume was high and did not change after weight reduction. However, if calculated as blood volume per kg body weight, the values were lower than normal, and they increased as a consequence of weight reduction. Cardiac output was slightly lower than normal in relation to oxygen consumption. Total peripheral resistance was normal. Arterial blood pressure, which was in the high normal range preoperatively, decreased significantly after weight reduction. Total doses of intravenous anaesthetic agents and muscle relaxants were the same as for patients of normal weight. The importance of preoperative evaluation and of respiratory care of obese patients undergoing elective surgery is stressed.
Blood Flow in the Rabbit Tracheal Mucosa under Normal Conditions and under the Influence of Tracheal Intubation
Authors: Nordin U. , Lindholm C.‐E. , Wolgast M.
Published: January 2009

Isotope la belled microspheres were used to study the capillary blood perfusion of the rabbit tracheal mucosa. Under resting conditions the perfusion was about 0.3 ml/min ® g (i.e. about 60% of the relative cerebral blood flow). Irritation of the tracheal mucosa by an endotracheal tube caused a steep rise in blood flow, tenfold or more. This was probably due to relaxation of the arterioles caused by a release of histamine‐like substances.

When an endotracheal tube is equipped with a small cuff (small resting diameter, low residual volume), the part of the mucosa in contact with the cuff, i.e. the mucosa covering the surface and edges of the cartilages, will be ischaemic at a cuff to tracheal wall pressure (C‐T pressure) of greater than 30 millimeters of mercury. This abrupt ischaemia threshold contributes to the risk of deep mucosal damage with subsequent tracheal scarring, possibly proceeding to stenosis. Our present studies indicate that the ideal large cuff, with properties resembling those of an air cushion, will allow the major part of the arterial pressure to be propagated as far down as the capillaries. Under these conditions the cuff would permit some of the capillary blood perfusion of the tracheal mucosa covering the cartilages also at C‐T pressures exceeding 30 mmHg.

Although this investigation supports the concept that the ideal thin‐walled large cuff interferes much less with the mucosal blood perfusion than the small cuff, we recommend that the cuff pressure be monitored and kept below 20 mmHg.
Cyclic AMP and Segmental Epidural Analgesia During Labour
Authors: Jouppila R. , Hollmén A. , Jouppila P. , Karppanen H.
Published: January 2009

The blood cyclic AMP level was determined just before, during and after induced labour in 27 healthy women. To achieve complete pain relief during the first stage of labour, 14 of them were given segmental epidural analgesia at the height of Th 10–12. The remaining parturients served as controls. Cyclic AMP was above the normal non‐gravid level before induction in both groups. In the control group the cyclic AMP content decreased during the first stage of labour, then it increased and reached a peak at the moment of delivery. These changes were, however, not significant. In the epidural group the cyclic AMP level rose significantly during the first stage, and also reached its peak at the moment of delivery. There was a statistically significant difference between the groups at a cervical dilatation of 6–8 cm. After delivery the cyclic AMP rapidly declined to its initial value in both groups. The possible role of the decreased uterine contractions after the block in the increase of the cyclic AMP is discussed.
The Cardiovascular Effects of Neuroleptanaesthesia
Authors: Brismar B. , Bergenwald L. , Cronestrand R. , Jorfeldt L. , Juhlin‐Dannfelt A.
Published: January 2009

Oxygen uptake, cardiac output, stroke volume and arterial and central blood pressures were measured before and after induction of neuroleptanaesthesia in 27 subjects. Nine were elderly patients operated on for obliterative arteriosclerotic disease, and the other 18—nine elderly and nine younger patients—underwent operation for varicose veins. Cardiac output, stroke volume and systolic arterial blood pressure decreased significantly with a corresponding decrease in oxygen uptake.

The changes were most pronounced in the patients with arteriosclerotic disease. The arterio‐venous oxygen difference was unchanged in the arteriosclerotics and decreased in the other two groups. The central pressures remained unchanged in all groups.

It is concluded that the cardiovascular changes induced by neuroleptanaesthesia are due to a decrease in oxygen uptake and not to myocardial depression.
Bupivacaine (Marcaine®): An Evaluation of its Tissue and Systemic Toxicity in Humans
Authors: Moore D. C. , Mather L. E. , Bridenbaugh L. D. , Thompson G. E. , Balfour R. I. , Lysons D. F. , Horton W. G.
Published: January 2009

In countries other than the U.S.A., dosages of bupivacaine have been limited to 100 mg without epinephrine and 150 mg with epinephrine. A review of 7,688 regional block procedures employing bupivacaine in concentrations of 0.25, 0.5, and 0.75%, and in dosages as high as 600 mg, indicated that such stringent restrictions: (1) are unwarranted, (2) make comparisons with other local anesthetic agents difficult, and (3) are in need of revision.
Hypoxia‐induced Vasoconstriction in Isolated Perfused Lungs exposed to Injectable or Inhalation Anesthetics
Authors: Bjertnæs Lars J.
Published: January 2009

Investigations during the last two decades have revealed a tendency to impaired pulmonary gas exchange in patients during general anesthesia. In the awake state, arterial hypoxemia is counteracted by a mechanism which tends to normalize the ventilation perfusion ratio of the lungs by way of a hypoxia‐induced vasoconstriction in poorly ventilated areas. This results in a redistribution of perfusion to more adequately ventilated lung regions. Recent observations suggest, however, that this beneficial mechanism is blunted by some commonly used inhalation anesthetics.

In the present study the effects of inhalation anesthetics and injectable anesthetics on the vasoconstrictor response to acute alveolar hypoxia have been compared in isolated blood‐perfused rat lungs. The experiments showed that the response was unaffected by N2O and injectable anesthetics, while a reversible, dose‐dependent damping effect was demonstrated for the volatile inhalation anesthetics, ether, halothane and methoxyflurane. The effect could be demonstrated at blood concentrations comparable to those used in clinical anesthesia, and it was not due to a general paralysis of the vascular smooth muscle. The findings might, at least in part, explain the occurrence of arterial hypoxemia during general inhalation anesthesia.
Anaphylactoid Reaction to Dextran—A Report of 133 Cases
Authors: Furhoff Anna‐Karin
Published: January 2009

From 1968 to 1975, the Swedish Adverse Drug Reaction Committee received 113 reports on anaphylactoid reaction to dextran 70, and 20 reports on the same reaction to dextran 40. For 1975, this would equal a reported incidence of anaphylactoid reaction to dextran 70 of 1:2,500. The median age of patients reacting to dextran 70 was 63 years. Median age increased with increasing severity of the anaphylactoid reaction: from 48 years in patients with skin symptoms predominantly, to 79 years in the five patients who died. Symptoms were noticed within 10 min of the start of the infusion, or before 100 ml had been infused in 96 patients (85%) with an anaphylactoid reaction to dextran 70. There was a tendency for severe reactions to be observed earlier than milder ones. Symptoms also tended to be observed earlier in conscious than in unconscious patients. Reactions reported to have occurred in unconscious patients tended to be more severe than those in conscious patients.

Patients with anaphylactoid reaction to dextran 40 did not differ from those with reactions to dextran 70 with regard to age, severity of the reaction or time before onset of symptoms. There was one death in this group.
Prostaglandin F2α as a Mediator of Pulmonary Changes during Platelet Aggregation
Authors: Rådegran Kjell , Olsson Per , Alme Björn , Granström Elisabet
Published: January 2009

Increases in pulmonary arterial pressure, tracheal insufflation pressure, and blood levels of the prostaglandin F2α metabolite, 15‐keto‐13, 14‐dihydro F2α, were observed after protamine chloride or thrombin‐induced platelet aggregation and release reaction in dogs. These effects were largely eliminated after administration of acetylsalicylic acid, an inhibitor of prostaglandin synthesis. The platelet aggregation was not noticeably affected.

It is suggested that release of prostaglandin F2α from platelets is an important factor for the pulmonary changes during induced platelet aggregation. The necessity of measuring metabolite levels, rather than prostaglandin F2α levels, in blood during in vivo conditions is demonstrated.
Selective Lumbar Epidural Block in Labour. A Clinical Analysis
Authors: Hollmen A. , Jouppila R. , Pihlajaniemi R. , Karvonen P. , Sjöstedt E.
Published: January 2009

Segmental epidural analgesia (T10‐T12) was performed in 418 parturients, using a 4–6 ml dose of 0.5% bupivacaine, with or without adrenaline. Seventy per cent of parturients were primiparas and 30% had histories, or signs, of possible uteroplacental insufficiency. Our aim was to relieve pain during the long passive opening phase, so that mothers would be rested and active at the beginning of the second phase, but also to avoid abolishing the bearing‐down reflex, the absence of which causes an increased frequency of instrumental delivery. The analgesia during the opening phase was of good quality in 89% of primiparas, and 84% of multiparas. The onset of analgesia was rapid (3–5 min) and the duration was on average 2 1/2 h. The incidence of foetal heart rate changes, during the 30 min after epidural, was 5%. The second phase was less than 30 min in about 90% of cases. About 90% of parturients delivered spontaneously, and the frequency of instrument delivery was only 7.4%. Caesarean section was required in 3.7%. Slight, but rapidly correctable, hypotension occurred in 16.5%, and in two cases the hypotension led to more serious complications. This stresses the importance of the availability and competence of both the anaesthetic and obstetric teams. There were no maternal or neonatal mortalities, and the Apgar scores compared well with the figures for the normal material in our obstetric unit.
Human Hepatic Blood Flow and its Relation to Systemic Circulation during Intravenous Infusion of Bupivacaine or Etidocaine
Authors: Wiklund Lars
Published: January 2009

Fifteen healthy young volunteers were studied before and during an intravenous infusion of a local anaesthetic agent. Seven received bupivacaine and eight etidocaine in a dose rate of 2 mg/min over a period of 150 min. Variables of the central systemic circulation and also the hepatic blood flow were measured repeatedly. The circulatory alterations during administration of the two drug s were compared. Comparisons with previous results concerning lidocaine and a placebo were also made. It was found that bupivacaine increased the heart rate, mean arterial blood pressure and cardiac output significantly more than did etidocaine in an equal plasma concentration. Lidocaine was intermediate between bupivacaine and etidocaine. In contrast, these three drugs had the same decreasing effect upon the splanchnic vascular resistance, which caused an almost identical increase in the estimated hepatic blood flow. The calculated vascular resistance in the systemic circulation, excluding the splanchnic, was unchanged during the infusion of etidocaine, while it decreased during the infusion of bupivacaine. Most of this discrepancy was due to the different plasma concentrations of the drugs.
Effect of Different Respirator Adjustments on Central Haemodynamics in Open‐Heart Surgery Patients
Authors: Laaksonen V. O. , Arola M. K. , Inberg M. V. , Irjala J. K. , Kari A. V.
Published: January 2009

Changes in cardiac index (CI), mean pulmonary artery pressure (PAP), mean pulmonary capillary wedge pressure (PCWP), central venous pressure (CVP), and pulmonary artery vascular resistance (PVR), associated with spontaneous respiration (SR) and two different types of intermittent positive pressure ventilation (IPPPV and IPNPV) were studied in a total of 17 patients undergoing aortic valve replacement or myocardial revascularization.

Swan‐Ganz thermodilution pulmonary artery cardiac output catheters were used and the aim was to determine: whether postoperative cardiac output may paradoxically be greater during IPPPV than during IPNPV or SR; whether the use of “negative” pressure in the expiratory phase during controlled ventilation may be responsible for bringing about the central haemodynamic conditions prevailing during spontaneous respiration; and whether, in weaning from postoperative IPPPV to SR, there is a risk of pulmonary congestion as a consequence of possible autotransfusion.

IPPPV connected with anaesthesia induction caused a highly significant deterioration of central haemodynamics. The use of positive end‐expiratory pressure (PEEP) is not to be recommended for such patients at this stage.

On the first postoperative day, the mean CI was lower during IPPPV than during IPNPV (P<0.1) or during SR (P<0.05). The changes observed in CI, were, however, so slight that the authors consider the routine use of PEEP to be beneficial during controlled ventilation following major open‐heart surgery. In some patients, the CI was paradoxically higher during IPPPV than during IPNPV or SR.

The mean CI was nearly the same during IPNPV (3.32) as during SR (3.38). However, PAP, PCWP and PVR values were significantly higher during SR than during IPNPV. Thus, according to this study, the use of “negative” end‐expiratory pressure during controlled ventilation did not in these patients produce central pressure conditions corresponding to spontaneous respiration.

The present study supports the finding that in weaning from controlled ventilation with PEEP to SR there is a danger of pulmonary congestion. This could be predicted by measurement of pulmonary wedge pressure, but not by measurement of central venous pressure.