bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on Muscle Relaxants During Haemodialysis
Authors: Cozanitis D. , Haapanen E.
Published: January 2009

Signs of neuromuscular block were evident more than 20 hours after the administration of alcuronium to an anuric patient. Complete recovery occurred during haemodialysis. We therefore decided to study the dialysance of three radioactive non‐depolarising relaxants during haemodialysis of four patients with chronic renal failure. Although dimethyl tubocurarine and alcuronium were equal as regards dialysance, the concentration of the former, in plasma, falls faster than does alcuronium. It is believed that a larger volume of distribution occurs with dimethyl tubocurarine. In spite of the fact that the dialysance of muscle relaxants is small, haemodialysis might lower the concentration of these substances in the plasma to a level below the critical point which produces paralysis.
Importance of Using Proper Techniques to Teach Cardiopulmonary Resuscitation to Laymen
Authors: Korttila K. , Vertio H. , Savolainen K.
Published: January 2009

Immediate attempts to resuscitate patients with cardiac arrest by lay bystanders distinctly increase the chances of survival in such patients. In the present study we investigated possibilities of intensifying the cardiopulmonary resuscitation (CPR) training of laymen. A group of 46 young conscripts (test group) was given 2 hours of CPR instruction in what was considered the most efficient way. The procedures included showing a film on the theory and practice of CPR, a discussion of the film, and then 3 to 5 min instructed individual practice with a recording manikin. Another 56 conscripts participated in a I‐h illustrated lecture on CPR, which was followed by group training with a non‐recording manikin; they served as a reference group. The performance of the subjects in CPR was measured with a recording manikin before and 2 months after the training. Before training, none of the subjects passed the surprise resuscitation test. After training, the skills of 62% of the subjects in the test group were acceptable according to original criteria for lay public, and 28% passed the test according to the strict criteria for medical personnel. The less intensive training given to the reference group did not improve the acceptability of resuscitation. It is concluded that CPR training for laymen may lead to failure to attain an adequate level of skill. Proper training techniques and equipment are important, but even their use does not guarantee that an adequate level of CPR performance will be attained by all laymen if their skills are not later refreshed.
Influence of General Anaesthesia on Portal Pressure in Liver Cirrhosis and Portal Hypertension
Authors: Burcharth F. , Alsner T. , Bertheussen K. , Rosendal T. , Nielsen S. E.
Published: January 2009

In 19 patients with cirrhosis of the liver and portal hypertension, a catheter was inserted into the portal vein using a percutaneous transhepatic technique. The portal pressure was measured during general anaesthesia with and without halothane, and in the awake state. Addition of halothane to the N2O:O2 anaesthesia did not change portal venous pressure, in spite of a significant fall in arterial blood pressure. Portal venous pressure under general anaesthesia with complete muscle relaxation did not differ from the pressure in the resting, awake patient.
Postoperative Arterial Oxygen Tension after Peroperative PEEP‐Ventilation
Authors: Berthelsen P. , Husum B. , Kortsen H.
Published: January 2009

Forty otherwise healthy patients (29 women and 11 men), undergoing elective cholecystectomy, were randomly allocated to he ventilated during the operation either with a positive end‐expiratory pressure of 1 kPa (10 cmH2O) (PEEP group) or with intermittent positive pressure ventilation without PEEP (control group). During the operation the mean arterial oxygen tension (Pao2) in the PEEP group increased from 14.6 to 16.5 kPa, while no changes occurred in the control group (13.5 and 13.6 kPa). On the first postoperative day, Pao2 decreased by 12% of the prcoperative values in the PEEP group; the decrease was 20% in the control group. On the third postoperative day, the Pao2, in the control group was still 9% below the preoperative values, but on the fifth day, both groups had reached their preoperative Pao2, values. In the postoperative period, no statistically significant difference in Pao2, could be demonstrated between the groups. Determinations of the forced vital capacity and forced expiratory volume in the first second showed no difference between the groups pre‐ or postoperatively. The present study demonstrated no clinically relevant beneficial effect of peroperative PEEP ventilation on the postoperative arterial hypoxaemia after an upper abdoniinal laparotomy.
Increased Serum Concentrations of Lactic, Pyruvic and Uric Acid and Bilibubin After Postoperative Xylitol Infusion
Authors: Korttila K. , Mattila M. A. K.
Published: January 2009

Xylitol has been suggested as a more advantageous calory source for intravenous administration than glucose in certain clinical situations, but the general suitability of intravenous xylitol infusion has not been confirmed. Thirty middle‐aged womm were infused with 100 g of xylitol as postoperative fluid therapy after gynaecological laparotomy and general anaesthesia. Another 10 women received 50 g of glucose in a similar manner and served as a reference group. Infusion of xylitol both at the rate of 0.25 g/kg/h (1000 ml 10% xylitol in approx. 8 h) and 0.5 g/kg/h (1000 ml 10% xylitol in approx. 4 h) caused a distinct increase in the serum concentrations of lactic acid, pyruvic acid, and uric acid; such an increase was not seen with glucose infusion. The faster infusion of xylitol also distinctly increased serum bilirubin roncentrations. Because of the possibility of lactic acidosis and urate deposits in kidneys, infusion of 100 g or more of xylitol at a rate of 0.25 g/kg/h or faster is not safe for postoperative fluid therapy in routine clinical work.
Effect of Different Anesthetics on the Pharmacokinetics and Pharmacodynamics of Pancuronium in the Cat
Authors: Miller R. D. , Agoston S. , van der Pol F. , Booij L. H. D. J. , Crul J. F.
Published: January 2009

To investigate the effect of different anesthetics on the pharmacokinetics and pharmacodynamics of pancuronium, 120 μg/kg i.v., cats were anesthetized with either pentobarbital (N = 4), ketamine (N = 4), enflurane (N = 5), or halothane (N = 5). A longer onset time and duration of neuromuscular blockade occurred during enflurane and halothane anesthesia. The apparent elimination half‐life was longer and the total volume of distribution at steady state larger during halothane anesthesia. The plasma concentration of pancuronium required for neuromuscular blockades was less during enflurane than during the other three anesthetics. We conclude lhat inhalation anesthetics may prolong a neuromuscular blockade by altering both the pharmacokinetics and pharmacodynamics of pancuronium.
Can Postoperative Pulmonary Conditions be Improved by Treatment with the Bartlett‐Edwards Incentive Spirometer after Upper Abdominal Surgery?
Authors: Lyager S. , Wernderg M. , Rajani N. , Boggild‐Madsen B. , Nielsen L. , Nielsen H. C. , Andersen M. , Møller J. , Silberschmid M.
Published: January 2009

During the immediate postoperative course after upper abdominal surgery. pulmonary complications often occur, caused, inter alia, by reduced regional ventilation and by atelectases as a result of: (1) narrowing of the small peripheral bronchi, and (2) impaired respiratory function. Based on these pathophysiological mrchanisms, an instrument (Bartlett‐Edwards Incentive Spirometer) has been devised, which aims at giving the patient an opportunity of sustained maximal inspiration under standardized and controlled conditions. The use of this instrument has been followed by reports of a considerable reduction in postoperative pulmonary complications.

In a controlled clinical investigation of the pre‐ and postoperative condition of the lungs, we were unable to show any beneficial effect of the instrument. In general, we have a low frequency of severe postoperative pulmonary complications, as compared with the results reported in the literature. We ascribe this to our very effective pre‐ and postoperative respiratory therapy.
Erythrocyte Damage Caused by the Haemotherm® Microwave Blood Warmer
Authors: Linko K. , Hynynen K.
Published: January 2009

Blood units (59) were warmed with the Haemotherm® microwave blood warmer and seven units were warmed in a water bath for comparison. The influence of the final blood temperature, the size and the hematocrit of the units on the erythrocyte lesion was studied. Extracellular hemoglobin and potassium, hematocrit, osmotic fragility and mean cellular volume were used as indicators of red cell damage. Warming in the water bath caused no erythrocyte damage at temperatures below +46.8°C. Higher temperatures caused progressive morphological changes and hemolysis. Units of red cells in saline warmed to temperatures above + 46.3°C with the Haemotherm showed intense hemolysis and changes in all parameters used. Below this temperature no erythrocyte damage occurred. When the amount of blood warmed was less than 300 g or when the hematocrit exceeded 0.70, the blood mixing mechanism became insufficient, leading to local overheating and hemolysis. Therefore, erythrocyte concentrates in a Fenwa® blood bag should never be warmed by the Haemotherm. The mean plasma hemoglobin increase of the ten whole blood units warmed by the Haemotherm to +36.0 —36.8°C was 123 mg/l. The results of the present study indicate that microwaves per se are not harmful to erythrocytes but that poor penetrance of microwaves, together with insufficient blood mixing during warming, are the critical factors leading to hemolysis.
Comparative Potency and Speed of Onset of Fazadinium and d‐Tubocurarine
Authors: Hussain S. Z. , Healy T. E. J. , Birmingham A. T.
Published: January 2009

The potency and speed of onset of fazadinium and d‐tubocurarine have been compared at three cumulative doses. With thiopentone as the induction agent, the dose ratio fazadinium/d‐tubocurarine ranged from 1.2 to 1.3 for single twitch reduction and from 1.1 to 1.2 for reduction of tetanus. The times taken for the development of 50% and 100% effect after each dose increment were not significantly different for the three doses of fazadinium and the 2nd and 3rd doses of d‐tubocurarine. However, the 1st dose of d‐tubocurarine was markedly slower than fazadinium to achieve a 50% and 100% effect.
A New Transducer for Respiratory Monitoring: A Description of a Hot‐wire Anemometer and a Test Procedure for General Use
Authors: Kann T. , Hald A. , Jørgensen F. E.
Published: January 2009

A respiratory transducer based on the constant temperature anemometry principle has been developed for respiratory monitoring, and as a tool for bedside evaluation of pulmonary function. The transducer is characterized by a dynamic range from 0–2.5 l/s and an upper limiting frequency of 50 Hz. It is designed with a view to a low pressure drop of 2.5 mbar/l/s and a minimum dead space of 5 ml. The transducer has been tested using a generally applicable procedure which includes both static and dynamic test set‐ups. The influence of variations in gas composition, temperature and pressure, together with variations in tidal volume and respiration rate, have been investigated. The results show that the transducer registers the immediate value of gas flow‐rate with a mean error less than 5–10% in all situations which are predictable in clinical use. The mean error can be reduced to less than 5% when systematic errors are eliminated.
Experimental Studies on Artificial Ventilation Using a Tidal Volume Ventilator Mechanics and Dynamics of Ventilation
Authors: Lindahl S. , Okmian L.
Published: January 2009

In 24 piglets (2.7–24.5 kg b.w.), the mechanics of ventilation, the accuracy of dosage of respiratory volumes, and the influence of the ventilator's volume/ pressure characteristics (Cvent “internal compliance”) on the dynamic course of insufflations were studied. A linear relationship was shown to exist between tidal volume and end‐aspiratory tracheal pressure and between tidal volume and insufflation time. The insufflation time was reduced to about 50% of previously registered values. The error between set and registered tidal volume was found to be 6.0 ± 2.7%. During the insufflation a linear relationship was found between the instant amount of delivered breathing gas and the corresponding endotracheal pressure change. The ventilator's Cven did (and body size, total compliance and tidal volume did not) significantly influence the size of the direction coefficient for the linear instantaneous volume/pressure relationship, the magnitude of tracheal peak pressure and the duration of the insufflation. A low Cvent resulted in a high peak pressure and a short insufflation time, and vice versa. The use of greater power from the ventilator resulted in a significant shortening of the duration of insufflation and vice versa. The duration of insufflation is the parameter of choice in evaluating the efficiency of the ventilatory equipment. When the ventilator's performance is defined, measurements of the duration of insufflation may enable evaluation of conditions within the lungs.
The Circulatory Response to Specific Ventilatory Patterns Using a Tidal Volume Ventilator
Authors: Lindahl S. , Kugelberg J. , Okmian L.
Published: January 2009

The circulatory response to different ventilatory patterns during artificial ventilation was examined in 17 sternotomized piglets. A constant CO2‐tension level was maintained in all investigations by reference to analyses of the end‐tidal infra‐red CO2 fraction and arterial CO2‐tension. The greatest variation in mean values for end‐tidal CO2‐tension was 0.2 kPa. Total compliance and lung compliance were lower at a ventilator volume/pressure quotient of 20 compared to those at 80 ml/ kPa, and at f = 30 compared to f = 11 cycles/min. Higher cardiac output, lower pulmonary vascular resistance and systemic vascular resistance were measured at f = 11 (inspiration 20%) than at f = 30 (inspiration 50%). An increase in inspiration time by about 100% at the lower ventilatory frequency (f = 11) resulted in an increased work load for the right heart, reflected by a small decrease in cardiac output (7%). Changes in the duration of inspiration by about 100% at the higher ventilatory frequency (f = 30) resulted in a significant but uncompensated decrease in cardiac output and stroke volume. These results demonstrate the value of a rapid insufflation in order to give longer expiration time per minute for the benefit of the venous return and cardiac output.
Effects of Thoracic Epidural Block and the Beta‐1 ‐Adrenoreceptor Agonist Prenalterol on the Cardiovascular Response to Infrarenal Aortic Cross‐Clamping in Man
Authors: Reiz S. , Nath S. , Pontén E. , Friedman A. , Bäcklund U. , Olson B. , Rais O.
Published: January 2009

Sixteen patients scheduled for abdominal aortic resection and grafting were randomly assigned to two groups to study the cardiovascular effects of infrarenal aortic cross‐clamping. The patients in the first group had received a thoracic. epidural block followed by intravenous administration of the selective beta‐l‐adrenoreceptor agonist prenalterol prior to induction of general anaesthesia. The patients in the second group served as controls and received no specific treatment prior to general anaesthesia.

In both groups, aortic cross‐clamping was followed by an equal rise in pulmonary artery diastolic pressure and mean systemic arterial pressure. There was a significant difference in systemic vascular resistance, as the control group had a 46% increase 30 s after cross‐clamping, while the pretreated patients had only a 7% increase at the same time. Moreover, the patients given the thoracic epidural block followed by prenalterol increased their stroke volume and cardiac indices, as compared to the patients in the control group who showed a significant decrease in these parameters.

Possible mechanisms for the mode of action of the combined thoracic epidural block and beta‐l‐adrenoreceptor agonist pretreatment are discussed.
Cameco Anaesthetic Ventilator With a Modified Mapleson D Circuit
Authors: Christensen K. Nørregaard , Jensen J. Kaalund
Published: January 2009

A modified Mapleson D circuit has been used in connection with a Cameco anaesthetic ventilator during neuroradiological procedures in general anaesthesia. In order to increase mobility of the patient, two or three lengths of corrugated rubber tubing were used to connect the patient to the ventilator. Blood gas analysis was carried out in 20 patients after ventilation to steady state with both circuits. The respiratory minute volume and fresh gas flow were preset from Bain's (Bain & Spoerel 1975) predictions. No significant difference could be detected in respect to Paco2 or Po2, whether 2 or 3 lengths of tubing were used. Mean values of Paco2 were higher compared with the results of Bain (0.37 kPa s.d. 0.50). It is concluded that this system gives maximum mobility of the patient during the radiological procedure and offers reliable adjustmcnt of Paco2 even in patients with apparent increase of intracranial pressure.
Epiglottitis Acuta Treated ith Nasotracheal Intbatiori
Authors: Enoksen Å. , Bryne H. , Hoel T.M. , Havnen J.
Published: January 2009

Twenty children, ranging in age from 1–9 years, and one adult suffering from epiglottitis acuta were treated with nasotracheal intubation performed under general anaesthesia and with ampicillin. Clinical cure was obtained in all cases with a meail intubation time of 34 hours. The diagnosis, epiglottitis acuta, was suspected by the referring physician in 10 cases. The incidence of epiglottitis acuta compared to laryngitis acuta was found to be 1:30. The mean hospital stay was 5.4 days. It is concluded that treatment of acute epiglottitis by nasotracheal intubation in the hands of experienced anaesthesiologists and with close observation in an intensive care unit, is a safe method of management with negligible morbidity and mortality.
Clinical Significance of Specific Gravity of Spinal Anaesthetic Agents Two Double‐Blind Studies with Hyperbaric 5% Lidocaine
Authors: Axelsson K. , Widman B.
Published: January 2009

In two double‐blind studies two hyperbaric 5% lidocaine solutions containing glucose in concentrations of 75 mg/ml and 50 mg/ml, respectively, were compared. The onset and total onset time, spread, intensity, duration of analgesia and motor block were studied. The spinal anaesthesia was given with the patient either sitting or in the lateral recumbent position. A tendency to a longer duration of anaesthesia near dermatomes Th X‐L II and L IV‐L V was noted in the group of patients in the sitting position and receiving lidocaine with a lower glucose concentration. Otherwise there were no differences between the two lidoraine solutions. The result shows that the glucose concentration can be reduced from 75 to 50 mg/ml in “heavy” lidocaine without any clinical disadvantage. This means a more isotonic solution in relation to the cerebrospinal fluid, resulting in milder osmotic effects on interspinal structures.
Anaphylaxis in the Monkey: Pulmonary Oedema after Pre‐treatment with β‐Receptor Stimulants
Authors: Revenäs B. , Smedegård G. , Arfors K.‐E.
Published: January 2009

Aggregate anaphylaxis was induced in seven ovalbumin‐sensitized monkeys, with high titres of ovalbumin specific haemagglutinating antibodies. After pre‐treatment with an intravenous (i.v.) injection of 0.25 mg/kg terbutaline (n = 6) cr an infusion of isoprenaline (n = 1), anaphylactic shock was induced by i.v. challenge with specific antigen. Haemodynamics, regional blood flows, respiratory mechanics, blood gases and haematological changes were studied during the following 30 min. Severe shock developed following ovalbumin challenge and the cardiac output was reduced by a mean of 74%. Pulmonary vascular resistance increased 11‐fold. Pulmonary dynamic compliance decreased, but there was only a minor increase in pulmonary resistance. Hypoxaemia and severe metabolic acidosis developed. Circulating platelets and leucocytes decreased markedly. Three animals died with fulminant pulmonary oedema. In conclusion, the reaction pattern was similar to that found in studies of monkeys that received no prior treatment. However, the occurrence of pulmonary oedema suggests that the effects of large doses of terbutaline on the heart, combined with the high pulmonary vascular resistance, resulted in more severe pulmonary changes than took place in untreated animals.
Renal Function and Fluoride Formation and Excretion During Enflurane Anaesthesia
Authors: Järnberg P.‐O. , Ekstrand J. , Irestedt L. , Santesson J.
Published: January 2009

Central circulation, renal function, and fluoride formation and excretion were studied in nine patients during enflurane anaesthesia and surgery. Cardiac output and mean systemic arterial pressure remained unchanged compared with preoperative control values. During anaesthesia and surgery, urine flow rate, inulin clearance, PAH clearance and fractional sodium excretion were 60, 65, 55, and 45% of control values, respectively. Mean peak plasma levrl of fluoride was 20.0 μM. It was reached 4 hours after termination of anaesthesia. Fluoridc clearance (CF) decreased from 23.9 ml. min‐1to 2.7 ml. min‐1during anaesthesia. Postoperative, CFincreased to 41.6 and 76.0 ml.min‐1, rrspectively, during two consecutive measurement periods. There was no correlation between plasma fluoride levels and depression of any renal function variable.
Continuous Positive Airway Pressure During Mechanical and Spontaneous Ventilation Effects on Central Haemodynamics and Oxygen Transport
Authors: Vuori A. , Jalonen J. , Laaksonen V.
Published: January 2009

The effect of continuous positive airway pressure during continuous mechanical (CMV + PEEP) and spontaneous (CPAP) ventilation on central haemodynamics and systemic oxygen transport was studied in 10 male patients who had undergone aortocoronary bypass graft operation 18 h earlier. With the change from CMV + PEEP 5 cmH2O to CPAP 5 cmH2O, cardiac index was found to increase from 2.58 + 0.44 (s.e. mean) to 2.88 2 0.19 1/min/m2 (P<0.005), and systemic oxygen transport improved from 8.5 ± 0.6 to 9.5±1.0 ml/min/kg (P<0.05). Arterial oxygen tension and content did not change, but mixed venous blood oxygen tension increased from 3.5 ± 0.2 to 4.2 ±0.2 kPa (P<0.005), reflecting the increase in cardiac output. Arteriovenous oxygen content difference decreased from 4.6±0.5 (CMV+PEEP) to 3.6±0.2 (CPAP) m1/100 ml (P<0.05), while total oxygen consumption remained unchanged. Mean systemic arterial pressure was found to increase from 10.8 ± 0.4 to 11.6 ± 0.4 kPa (P< 0.05) and mean pulmonary arterial pressure changed from 2.2 ±0.1 to 2.4 ±0.1 kPa (P<0.05). Right atrial and pulmonary capillary wedge pressures did not change. Our observations suggest that, in terms of central haemodynamics and tissue oxygen supply, CPAP offers a noteworthy alternative weaning method and an alternative to CMV+PEEP in cases where therapy is prolonged and the patient is able to breathe spontaneously.
Myocardial Performance Early After Aorto‐Coronary Bypass Surgery Cardioplegic Arrest Versus Coronary Perfusion
Authors: Tydén H. , Johansson L. , Nyström S.‐O.
Published: January 2009

Haemodynamic adaptation was studied during the first 10 h after aorto‐coronary bypass surgery. In a control group of 12 patients the heart was fibrillating and perfused during cardiopulmonary bypass (at 30°C), and in 11 patients cold cardioplegic arrest was used. The first 4–5 h were characterized by rewarming, with increasing oesophageal temperature, cutaneous vasoconstriction and elevated systemic vascular resistance (SVR). A phase of vasodilation followed. In the control group the oxygen uptake index increased by 57% during rewarming, but the cardiac index (CI) was constant (about 2.8 1 min‐1 m‐2). The arterio‐venous oxygen content difference (AVDo2) therefore increased (max. 3.0 mmol 1‐‐1). The postoperative left ventricular performance was better and the serum levels of aspartate aminotransferase (ASAT) during the first 2 days postoperatively were lower in the cardioplegic patients than in the controls, indicating more efficient myocardial preservation. In the cardioplegic‐hypothermic group, CI was constant at about 3.2 1′min‐1 m‐2 (significantly higher than in the control group) and AVDo2 remained normal during the rewarming period. The heart rate was lower initially in the cardioplegic patients than in the controls, implying a favourable influence on myocardial oxygen consumption. The better myocardial function in the cardioplegic‐hypothermic group was associated with an only moderately increased SVR. This suggests that the elevated SVR in the control group could have been due to myocardial depression.
Serum Bromide After General Anaesthesia with Halothane
Authors: Meldgaard O. T. , Cold G. E.
Published: January 2009

Serum bromide was determined in 30 patients during the first few postoperative days after general anaesthesia with halothane. The material comprised a group of younger patients (19–50 years) and a group of elderly patients (>70 years), neither of whom received thiomebumal induction, and a group of younger patients (19–50 years) who received thiomebumal induction.

The changes in serum bromide were independent of age and induction with barbiturate, and a maximum rise in serum bromide was found most often 2–3 days after the anaesthesia. All groups showed a rise in serum bromide to thera‐peutically sedative concentrations, and a significant correlation was found between MAC‐hours halothane exposure and serum bromide.
Effect of Segmental Epidural Analgesia upon the Uterine Activity with Special Reference to the Use of Different Local Anaesthetic Agents
Authors: Willdeck‐Lund G. , Lindmark G. , Nilsson B. A.
Published: January 2009

Segmental epidural block was given to 60 primiparous women during vaginal delivery, and the effect of the block on the uterine activity was studied after the first epidural injection. The women were divided into two main groups, according to whether or not oxytocin was used for stimulating the uterine contractions, and three different local anaesthetics—lidocaine‐adrenaline, bupivacaine‐adrenaline and plain hupivacaine—were tested.

There was a transitory decrease in uterine activity in all women after the block was applied. In women with normal uterine activity before the block, a return to almost pre‐analgesic values was noted within 30 min after the block, whereas in women treated with oxytocin there was still a reduction of 15–17% at this time. The reduction was caused by a decreasing intensity and at the same time an increase in the variability of the intensity, manifested as an increase in the coefficient of variation for this variable. There were no significant differences between the local anaesthetic agents tested, hut addition of adrenaline to the bupivacaine solution resulted in a more marked decrease in uterine activity in women treated with oxytocin.
Influence of Body Temperature During Cardiopulmonary Bypass on the Haemodynamics Early after Aorto‐Coronary Bypass Surgery
Authors: Tydén H.
Published: January 2009

The haemodynamic Actaptation early after aorto‐coronary bypass surgery, with special reference to the influence of body temperature on postoperative vaso‐constriction, was studied in 20 patients. Cardioplegic arrest was used in all cases. Eleven patients were cooled to 30°C during cardiopulmonary bypass, and nine were normothermic (37.5®) while the heart was cooled selectively. The normo‐thermic patients had significantly higher oesophageal and skin temperatures in the immediate postoperative period, indicating better heat preservation. However, the systemic vascular resistance was similar in the two groups; i.e. it was moderately elevated initially and subsequently decreased. There was no significant difference regarding postoperative myocardial function. The normothermic patients woke up earlier after the operation than the hypothermic patients, and since they also had a relatively low oxygen uptake index (0.10–0.12 mmol's‐l. m‐2), the possibility of earlier extubation in these patients is suggested.
Lung Uptake of Lidocaine in Healthy Volunteers
Authors: Jorfeldt L. , Lewis D. H. , Löfström J. B. , Post C.
Published: January 2009

Eleven patients with no known history of heart or lung disease received an i.v. bolus injection of a mixture of lidocaine and indocyanine green dye (Cardiogreen®). The dose of lidocaine, given once (or twice 10 min apart), was 0.5 mg/kg b.w. Time concentration curves from the appearance of indocyanine green were constructed for both substances from blood samples taken from the common femoral artery for approx. 50 s at the rate of one sample every 1.2 s. The extraction of lidocaine in each sample and the uptake of lidocaine, when 95% of the injected dose of indocyanine green had been recovered, were calculated. Nine patients showed an initial plateau of high extraction, which was 0.92 ±0.02 (± s.e. mean) and 0.91±0.02 for the first and second injections, respectively, for the entire material. In two cases, however, a short plateau and a rapid decline in the extraction curve were observed. The 95% first pass uptake was 60 ± 5% in the first injection and 55±12% for the second injection. Extraction of lidocaine dominated over back diffusion for approximately 25 s. It is concluded that: (1) The described technique for studying lung uptake gave consistent and reproducible results in human volunteers; (2) Lung uptake of lidocaine in healthy man exceeds that previously observed in anaesthetized pigs; (3) The initial uptake during the first 5 s after appearance of indocyanine green in the arterial samples was more than 90%. (4) The lungs thus have a dampening effect on the arterial concentration, which might be of importance if lidocaine is accidentally injected intravenously.
Artificial Ventilation in Children During Anaesthesia Using a Tidal Volume Ventilator
Authors: Lindahl S. , Okmian L. , Thomson D.
Published: January 2009

Standards for artificial pulmonary ventilation at ventilatory frequencies of 15 and 20 cycles per min, (Petcos 4 ± 0.5 kPa), were defined in 16 children with healthy lungs and body weights between 2.6 and 22.6 kg. A tidal volume ventilator and balanced anaesthesia were used during abdominal surgery. At f = 20 cycleslmin an approximately direct proportionality existed between tidal volume and body weight (Vtpat = 12.3.kgb.w.‐2.1, r = 0.99). The mean value Vtpat per kg b.w. was 12.1 ± 1.4 ml/kg. At f = 15 cycles/min, a linear relationship between tidal volume and kg b.w. was recorded (Vtpat = 14.6 kg b.w.+ 16, r = 0.97). The mean value Vtpat per kg b.w. was 15.9 ± 1.5 ml/kg. A significant decrease in total compliance was recorded during the initial part of the surgical procedure. A rectilinear relationship existed between total compliance and kg b.w. (ctot = 11.2 kg b.w.— 12.5, r = 0.95). The mean value CTOT per kg b.w. was 9.7± 0.54 ml/kPa/kg at f = 20. The endotracheal peak pressure maintained a fairly constant pressure level independent of the initial pressure within the ventilator, the tidal volume and the body weight, a phenomenon explained by the hypothesis that the proportional increase in total lung volume and functional residual capacity in the older children compensated for the higher pressures.
Open Scavenging Systems
Authors: Paloheimo M. , Salanne S. O.
Published: January 2009

A mathematical model was developed to cover the dynamic characteristics of open scavenging systems. The performance of such a device depends on the expiratory tidal volume (VT), the scavenging flow (VS) and the mode of exhalational voliimc build‐up. A widely used open scavenging system was tested by using carbon dioxide in oxygen as a marker gas. Capnography revealed gross turbiilence in the expiratory reservoir, which tends to increase the polluted gas volumrs and loads extra requirements onto the scavenging equipment. Increases in the scavenging flow or the expiratory reservoir volume are the aids in obtaining satisfactory safety margins for pollution‐free scavenging of surplus anaesthetic gases. The tliroretical basis of a new method to determine the expiratory time constant of the respiratory system is also presented.
An In Vitro Comparison of Six Microaggregate Blood Filters
Authors: Linko K.
Published: January 2009

The latest models of six blood microfilters were tested by filtering large amounts of pooled blood at various driving pressures. For determination of the amount and size of microaggregates in stored blood, a simple method was developed, based on consecutive nylon screens. The amount of aggregates was also determined by a modification of the screen filtration pressure method. Filtration efficiency was tested by transfusing blood from the same pool through each of the microfilters. The Pall® (SQ40KL) filtered only particles with a diameter greater than 40 pm. Small aggregates passed also through Bentley® (PFF‐100). The Biotest® (MF10B) filter removed large aggregates efficiently, but some small particles were not filtered. Fenwal® (4C2423), Swank® (6010–3) and Intersept® (HRI 8137–00) were the most effective filters. All filters were also tested by pressure transfusion of pooled blood (9 units, 21 days old). The efficiency of Biotest, Pall and especially Bentley improved considerably during the transfusion. Bentley and Fenwal had the highest capacities. A high flow rate was maintained with Pall, but small aggregates were not removed by this filter. Intersept, Swank and Biotest became occluded rapidly. Filtration of four units through Intersept released 2218–2454 mg of hemoglobin from the erythrocytes.
Hemodynamic and Cardiometabolic Effects of Prenalterol in Patients with Gram Negative Septic Shock
Authors: Reiz S. , Friedman A.
Published: January 2009

The hernodynamic eflects of prenalterol, a new inotropic agent, were investigated in 10 patients with gram negative septic shock. In four of the patients, coronary sinus blood flow (CSF) and myocardial oxygen and lactate extraction were also determined. After baseline hemodynamic measurements, prenalterol was infused intravenously over a 10‐min period to a total dose of 150 pg/kg. All patients responded within 15 min after completion of prenalterol infusion by increasing mean arterial pressure from 57±11 to 75 ± 20 mmHg (7.58f 1.46 to 9.97±2.66 kPa), (+32%), (P<0.01) and cardiac index from 2.65±0.40 to 3.80±0.47 l min‐lm‐2(+44%) (P< 0.001). There was no change in heart rate or systemic vascular resistance, nor were any arrhythmias recorded. The urinary output increased significantly. After prenalterol, CSF increased from 185kl 4 to 246±14 ml.min‐1, (+33%), (P<0.001) and myocardial oxygen and lactate extraction rose from 19.8±2.1to26.6±2.1 ml O2.min‐1, (+ 34%) (P<0.00l) andfrom33.2±2.3 to44.7k2.1 μmol.min‐1, (+35%), (P<0.001), respectively. The total body oxygen consumption increased from 287f 13 to 348±23 ml O2.min‐1, (+21 %), (P<0.01) and the arterial lactate concentration decreased from 5.61±0.55 to 3.94±0. 16 mmol.l‐1, (‐ 30%), (P<0.01), suggesting improved tissue perfusion. The results demonstrate that prenalterol is a potent, highly selective inotropic agent inducing the same magnitude of increase in blood pressure and cardiac output as reported for dopamine in septic shock.
Influence of Epidural Analgesia on the Catecholamine and Cyclic AMP Responses to Surgery
Authors: Engquist A. , Fog‐Møller F. , Christiansen C. , Thode J. , Vester‐Andersen T. , Madsen S. Nistrup
Published: January 2009

The effects of neurogenic block on plasma concentrations of adrenaline, noradrenaline and cyclic AMP were studied. Eighteen patients were subjected to surgery of moderate or minor extent under enflurane anesthesia with or without epidural analgesia. The results show that adrenaline secretion during surgical stress is a response to neurogenic stimuli, since the increase found in patients subjected to hysterectomy under general anesthesia is blocked by the addition of epidural analgesia. Furthermore, plasma adrenaline after neurogenic block is comparable with adrenaline levels during minor surgical stress.

The plasma noradrenaline concentration does not correlate with the extent of trauma. In contrast to adrenaline levels, noradrenaline concentrations varied insignificantly during and after surgery. However, the addition of epidural block induced a postoperative increase in noradrenaline apparently unrelated to changes in heart rate or blood pressure. Simultaneous measurements of the catecholamines and cyclic AMP indicate that adrenaline is of minor importance for plasma cyclic AMP in resting patients, whereas the increase in cyclic AMP elicited by surgery reflects adrenaline‐stimulated beta‐adrenergic activity.
Sister Chromatid Exchanges in Lymphocytes in Operating Room Personnel
Authors: Husum B. , Wulf H. C.
Published: January 2009

Sister chromatid exchanges (SCE) and sister chromatid exchange points (SCE‐points) were counted in lymphocytes in peripheral blood drawn from hospital personnel exposed to anaesthetics as well as from persons not exposed.

A total of 38 healthy persons were investigated, representing female nurse anaesthetists, male physicians practising anaesthesia, female nurses from the intensive care unit, and female secretaries.

The mean SCE number per cell for each person was used as the variable, and the Mann‐Whitney U‐test was applied to test for differences between groups. The group of secretaries seemed to differ from the other three groups, which appeared identical (P<0.001). Correlation of cigarette smoking and number of SCE could not be demonstrated (r=.255, n = 38).

It was concluded that by this method there was no indication of a mutagen effect of long‐term exposure to waste anaesthetic gases such as halothane and nitrous oxide.
Reduction of the Risk of Acid Pulmonary Aspiration in Anaesthetized Patients after Cimetidine Prernedication
Authors: Salmenperå M. , Korttila K. , Kalima T.
Published: January 2009

Forty‐two patients undergoing elective general surgery received either placebo, cimetidine 300 mg, or cimetidine 600 mg orally 1.5–2 h before anaesthesia in a double‐blind, randomized study. Another 13 subjects received no oral premedication and served as a control group. When compared to placebo or control patients, both doses of cimetidine significantly (P< 0.01) decreased the acidity and volume of gastric contents. None of the subjects given cimetidine were in the risk range of acid pulmonary aspiration (pH under 2.5 plus volume over 25 ml), whereas 46% of the control patients and 40% of the patients given placebo (P<0.005 vs cimetidine in both groups) were in the risk range.
The Role of Thiopental and Fentanyl in the Production of Balanced Anaesthesia
Authors: Tammesto T. , Aromaa U. , Korttila K.
Published: January 2009

In order to clarify the interactions between various doses of thiopental and fentanyl in producing “balanced anaesthesia”, their effects on consciousness, superficial nociception, and respiration and circulation were studied during N2O f O2 inhalation in connection with the induction of anaesthesia. Altogether 60 patients were studied; the drug combinations used were thiopental 5 mg/kg (TPs), thiopental 3 mg/kg (TP,), thiopental 3 mg/kg and fentany1 0.5 μg/kg (TP3Fo5), thiopental 2 mg/kg and fentanyl I pg/kg (TPPFI), thiopental 1 mg/kg and fentanyl 2 μg/kg (TP1F2), and fentanyl 3 μg/kg (F3). Five minutes after the i.v. supplementation of N2O+ O2 anaesthesia, the depth of anaesthesia and analgesia (antinociception) were evaluated from the eyelid reflex and by pinching an inguinal skin fold. Cardiorespiratory parameters were measured during this study period at 1 ‐min intervals.

The balance between antinociception and anaesthesia was closest to optimum in groups TP2F1 and TP3Fo5.

In pure thiopental groups, the analgesia was poor; only four patients did not respond to the nociceptive stimulus, whereas in group F3 anaesthesia (disappearance of the eyelid reflex) was obtained in only two patients. The respiratory depression was most pronounced in groups receiving 3,2 and 1 μg/kg fentanyl and weakest in groups where only thiopental was used. Blood pressure decreased in all groups but no statistically signscant diKerences were noted.

On the basis of the results it seems obvious that attempts to achieve what is called “balanced anaesthesia” by the supplementation of an N2O + O2 mixture with fentanyl only leads to an unnecessarily pronounced respiratory depression, whereas supplementation with thiopental alone does not offer adequate antinociception.
The Role of Diazepam and Fentanyl in the Production of Balanced Anaesthesia
Authors: Aromaa U. , Korttila K. , Tammisto T.
Published: January 2009

The effects of diazepam‐fentanyl combinations on consciousness, superficial nociception, respiration and circulation during N2O + O2 inhalation were studied in 40 premedicated patients during induction of anaesthesia. The balance between antinociception and anaesthesia was closest to the optimum in patients receiving 0.2 mg/kg of diazepam plus 1 μg/kg of fentanyl; the eyelid reflex was negative in all patients and only two out of ten patients reacted to abdominal pinching. When only 0.2 mg/kg of diazepam was given with N2O + O2, the eyelid reflex was negative in all patients, but half of them reacted to pinching. When the dose of diazepam was reduced to 0.1 mg/kg and patients received 1 or 2 μg/kg of fentanyl, the balance between anaesthesia and antinociception was good, but 30–50% of patients had a positive eyelid reflex and reacted to pinching. No distinct respiratory depression was observed in patients given 0.2 mg/kg of diazepam, whereas seven patients given 0.1 mg/kg of diazepam plus 2 μg/kg of fentanyl had apnoea lasting more than 60 s associated with a significant (P<0.05–0.001) increase in end‐tidal CO2 and PCO2 in arterialised venous blood.

No significant changes were observed in blood pressure or heart rate after any of the drugcombinations studied.

It appears that an optimal balance between anaesthesia and antinociception with minimal side‐effects during balanced general anaesthesia requires reinforcement of N2O+O2 anaesthesia not only with fentanyl but also with hypnotics or sedatives.
Calculation of the Fresh Gas Flow Requirements of the Hafnia A and D Anaesthetic Circuits
Authors: Thomsen A.
Published: January 2009

Semi‐closed anaesthetic circuits are converted into the corresponding Hafnia circuits by replacing the expiratory valve by a side tube connected to an ejector flowmeter. Theoretical analysis of the Hafnia A and D circuits revealed that the fresh gas flow requirements are dependent on the inspiration/expiration time ratio. Using a ratio of 1/1.2 and a sine‐wave respiratory waveform, the minimal fresh gas requirements were calculated as 2.1 (Hafnia A) and 2.5 (Hafnia D) times the respiratory minute volume. The fresh gas requirements are identical with spontaneous or controlled ventilation.
Influence of the Taurus® Radiowave Blood Warmer on Human Red Cells Hemolysis and Erythrocyte ATP and 2,3 DPG Concentrations Following Warming by Radiowaves, Microwaves and Water Bath
Authors: Linko K. , Hekali R.
Published: January 2009

The warming properties of the Taurus® radiowave blood warmer were studied. The safety limits were the same as for microwave warming (Haemotherm®). Hemolysis was noted in units with a hematocrit over 0.75 or containing less than 300 g of blood. The effects of radiowave, microwave and water bath warming on the erythrocyte ATP and 2,3 DPG concentrations were compared. Statistically highly significant differences were found between all these methods. Warming of blood in a +35'C water bath for 3 min had no effect on these parameters. There was, however, a tendency for ATP and 2,3 DPG levels to decrease after 60 min water bath incubation (+37 and + 45°C), but to increase levels following electromagnetic warming depending on the age of the warmed erythrocytes. Thus, electromagnetic radiation appeared to influence the red cell metabolism, which cannot be explained by the effect of temperature alone.
Hypoxia‐Induced Pulmonary Vasoconstriction: Effects of Fentanyl Following Dfierent Routes of Administration
Authors: Bjertnæs L. , Hauce A. , Kriz M.
Published: January 2009

Recent investigations have revealed that intravenous anesthetics, including fentanyl, do not reduce the pulmonary vasoconstrictor response to alveolar hypoxia. In contrast, the response is markedly reduced or abolished by inhalation anesthetics. Recent investigations have demonstrated that the route of administration is of importance. Halothane, which inhibits the response when administered via the airways, behaves more like an intravenous anesthetic following administration via the blood stream, provided the alveolar concentration has been kept low (Bjertnæs et al. 1977). It was therefore a distinct possibility that the lack of any damping effect of fentanyl on the response could be due to the route of administiation rather than to a different pharmacological property. We have tested this hypothesis by introducing fentanyl in nebulized form via the airways in one group of isolated rat lungs, and via the blood stream in another group. We found, however, no effect of fentanyl on the pulmonary vasoconstrictor response to hypoxia, regardless of the route of administration. Plasma concentrations of fentanyl were determined by radioimmunoassay and compared with those encountered in anesthetic practice.
Cimetidine in the Prevention of Acid Aspiration during Anesthesia
Authors: Kirkegaard P. , Sørensen O. , Kirkecaard P.
Published: January 2009

In a controlled, randomized, double‐blind trial, the value of cimetidine as prophylaxis against acid aspiration pneumonitis was studied. Compared to placebo, cimetidine reduced the volume as well as the acidity of the gastric contents significantly. The patients at risk of developing severe pneumonitis after aspiration (pH<2.5 and volume>20 ml) were reduced from 55% in the placebo group to 0 in the group having received cimetidine 400 mg the night before and a further 400 mg on the morning of surgery. Premedication with cimetidine may be useful if rapid intubation cannot be anticipated.
Immediate Hemodynamic Effect of Pharmacological Doses of Methylprednisolone in Dogs, and the Influence of Speed of Injection
Authors: Husum B. , Palm T. , Andersen K. , Vejlsted H.
Published: January 2009

Reports of sudden death of patients during i.v. administration of methylprednisolone (M.P.) prompted the present study of the hemodynamic effect of M.P. given i.v. to dogs. Fifteen healthy, mongrel dogs were anesthetized with thiomeburnal, fentanyl, droperidol, pancuronium and N2O/O2. With ventilation and circulation in steady state, M.P. 30 mg/kgb.w. was given i.v. either as a push bolus (n= 7) or over a5‐min period (n = 8). In the bolus group, mean aortic pressure (MAP) and systemic vascular resistance (SVR) had decreased to 72 and 60%, respectively, 1 min after the start of the steroid injection, while heart rate (HR), cardiac index (CI), mean pulmonary arterial pressure (MPAP) and left ventricular work (LVW) had not changed significantly. In the 5‐min group, the HR increased by 23 %, while the other parameters were unchanged during the injection period. Within 5 min after the termination of the steroid injection all hemodynamic parameters had returned to pre‐injection levels in both groups. Sodium, potassium, magnesium, protein and calcium in serum were unchanged in both groups during the injection period and in the following 15 min. A significant, transient fall in ionized calcium was observed in all six dogs in which this ion was measured.

It was concluded that rapid i.v. injection of pharmacological doses of M.P. in hemodynamically stable, anesthehed dogs causes immediate, transient decreases in SVR and MAP. The mechanisms may be an alpha adrenergic blocking action or a direct effect on the muscles in the peripheral vessels, combined with a negative inotropic effect on the myocardium, possibly mediated through an impeded calcium release.