bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of Halothane Anaesthesia upon Cerebral Oxygen Consumption in the Rat
Authors: Harp J. R. , Nilsson L. , Siesjö B. K. 
Published: January 2009

The influence of halothane (0.6 and 2%) upon cerebral (cortical) blood flow (CBF) and cerebral metabolic rate for oxygen (CMRo2) was studied in artificially ventilated rats, using a modified technique of Kety & Schmidt (1948). The values obtained in halothane anaesthesia were compared to those recorded in nitrous oxide anaesthesia, or to those measured in unanaesthetized animals given an analgesic drug (fentanyl citrate).Although it could be confirmed that halothane induces vasodilatation in the brain, there were relatively small differences in CBF between the groups. The results demonstrate that, in the rat, halothane depresses CMRo2 in a dose‐dependent way. With 0.6% halothane, CMRo2 was reduced by 20–30% and, with 2% halothane, CMRo2 was reduced by about 50%. Thus, in the rat the effect of 2% halothane upon metabolic rate is comparable to that observed in barbiturate anaesthesia.
Halothane Anaesthesia and Suxamethonium I: The Significance of Preoperative Atropine Administration
Authors: Viby‐Mogensen J. , Wisborg K. , Gabrielsen J. , Spotoft H. 
Published: January 2009

Preoperative administration of atropine was evaluated during induction of halothane anaesthesia with two administrations of suxamethonium 1 mg/kg body weight, 5 min apart.Sixty‐eight healthy, adult patients were studied. They were divided into five groups according to dose and route of administration of atropine. EGG was continuously monitored. Serum potassium, pH, Paco2, Pao2 and standard bicarbonate were measured at appropriate intervals.It was found that neither atropine 0.01 mg/kg body weight given intramuscularly 1 h before the anaesthesia nor atropine 0.01 mg/kg body weight given intravenously 5 min prior to induction protected against serious bradycardias (defined as heart rate below 20 beats per minute) following the second dose of suxamethonium.No serious brady‐arrhythmias were seen in patients given either a combination of intramuscular and intravenous atropine in the above‐mentioned doses or in patients given atropine 0.015 mg/kg body weight intravenously 5 minutes prior to induction. However, a decrease in heart rate to around 40–50 beats per minute occurred in some of these patients. Furthermore, these large doses of atropine caused an increase in heart rate during induction to more than 120 beats per minute in about 50% of the patients and to more than 140 beats per minute in about 25% of the patients.Our results suggest that preoperative administration of atropine does not protect against serious brady‐arrhythmias following a second dose of suxamethonium, unless doses of atropine are used which cause tachycardia of considerable degree.
Halothane Anaesthesia in Caesarean Section
Authors: Kangas L. , Erkkola R. , Kanto J. , Mansikka M. 
Published: January 2009

The safety and efficacy of halothane anaesthesia were investigated in 97 caesarean sections using 0.4–0.6% halothane added to a mixture of 6 1 N2O/3–4 1 O2. The administration of halothane was initiated before intubation and terminated immediately prior to delivery. Only one patient reported memories from the operation. The mean Apgar score 1 min after delivery (8.5) was significantly better than that (8.2) in 100 caesarean sections in which a mixture of 7 1 N2O/3 1 O2 was used.In 17 caesarean sections, the halothane concentrations were examined after 0.9% halothane had been given for exactly 1 min after intubation. It was found that halothane reached and passed the placenta after only 1 min. The levels in the maternal artery and umbilical vein were comparable. The levels in the maternal artery, maternal vein and umbilical vein were markedly higher than in the umbilical artery, which indicated an accumulation of halothane in the foetal tissues. However, due to the vigour of the newborn, halothane concentrations 10 min after birth were very low. The half‐life of halothane in the maternal circulation was approximately 1 min with the described method of administration.Blood gas determinations, which were made in seven newborns, proved satisfactory.
The Antagonist Effect of Naloxone Hydrochloride after Neuroleptanaesthesia during Neurosurgery
Authors: Arnér Staffan , Gordon Emeric 
Published: January 2009

The effects of naloxone were studied in 82 patients undergoing intracranial surgery under general anaesthesia with fentanyl or phenoperidine. After the operation was finished the patients' alertness, sensitivity to pain, blood pressure, pulse rate, respiratory rate, tidal and minute volume were recorded parallel with arterial blood gas analyses prior to and immediately after the administration of varying amounts of naloxone i.v. in a single dose. These parameters were also repeatedly controlled for several hours in the postoperative period.The results show that a single i.v. naloxone dose of 1 μg/kg b.w. is effective in the rapid and definite reversal of the respiratory depression caused by the analgesics. This dose was neither correlated to the total amount of analgesics given, nor to the time period which elapsed between the last dose of the analgesic drug and the administration of naloxone. No side effects or complications were encountered when the indicated doses of naloxone were given. It is concluded that, even in a small single dose, naloxone effectively antagonises the respiratory depression caused by fentanyl and phenoperidine without totally eliminating the immediate postoperative analgesic effects of these agents.
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.
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.
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.
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.
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 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.
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.
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.
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.
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.
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.