bluuebunny/crossref_metadata_2025 huggingface dataset:
Per‐ and Postoperative Monocyte and Lymphocyte Functions: Effects of Combined Epidural and General Anaesthesia
Authors: Hole A.
Published: January 2009

Monocyte‐mediated cytolysis and thymidine uptake in phytohaemagglutinin‐stimulated lymphocytes during and after hip replacement performed under combined epidural‐ and general anaesthesia were studied using in vitro culture techniques. Monocyte‐mediated cytolysis was unchanged during operation but was significantly reduced on the first postoperative day, coinciding with an increasing serum cortisol which indicates an incomplete epidural analgesia. However, there was no significant correlation between the increased cortisol concentration and the reduction of cytolysis. Lymphocyte proliferation was unchanged both during and after operation. These findings indicate that the presence of anaesthetic agents during surgery does not influence the studied functions of monocytes and lymphocytes. This supports the hypothesis that monocyte and lymphocyte depression during surgery under general anaesthesia alone is due to the trauma‐induced stress reaction. The difference between postoperative suppression of monocytes and lymphocytes in this study indicates that monocytes are more vulnerable to surgical stress than lymphocytes.
Intravenous Infusion of Halothane Dissolved in Fat. Haemodynamic Effects in Dogs
Authors: Biber B. , Johannesson G. , Lennander Ö. , Martner J. , Sonander H. , Werner O.
Published: January 2009

Eight harrier dogs received an i.v. infusion of halothane dissolved 1:9 in a fat emulsion for i.v. nutrition (Intralipidr̀, Vitrum). The rate of infusion was adjusted to maintain end‐tidal halothane concentrations of 0.7% and 1.4%. At 1.4%, mean arterial pressure decreased to 76 ± 8 mmHg (10.1 ± 1.0 kPa) (mean ± s.e.mean) from a pre‐infusion value of 122 ± 6 mmHg (16.2 ± 0.8 kPa) (P<0.01). The concomitant decrease in cardiac output was 39% and left ventricular maximum dp/dt decreased by 50% (P<0.01). Changes in systemic vascular resistance and pulmonary arterial pressure were small. The haemodynamic responses during halothane inhalation, to corresponding end‐tidal concentrations, were similar. Arterial and mixed venous halothane concentration increased in proportion to end‐tidal concentration. There were no changes in arterial Po2 during the halothane‐in‐fat infusion. Triglyceride concentrations in plasma increased 12‐fold. Haemodynamic recovery after the infusion was fast. We conclude that the halothane‐in‐fat infusion caused a dose‐dependent depression of myocardial contractility and arterial pressure, similar to that seen during inhalation, and that end‐tidal concentration could be used for control of the infusion rate.
General Anaesthesia with Halothane and Drug Absorption: The Effect of General Anaesthesia with Halothane and Diazepam on Postoperative Gastric Emptying in Man
Authors: Adelhøj B. , Petring O. U. , Erin‐Madsen J. , Angelo H. , Jelert H.
Published: January 2009

The effect of general anaesthesia with halothane on postoperative absorption of paracetamol was measured in seven patients, after minor surgery on the extremities. Gastric emptying, estimated indirectly by the rise in serum paracetamol following oral administration of the drug, was significantly delayed after general anaesthesia with halothane compared with gastric emptying when general anaesthesia with halothane was not administered. It was furthermore demonstrated that absorption of paracetamol and therefore gastric emptying were normal or nearly normal when diazepam 15 mg was given orally to the same patients 2 weeks later.
Epidural Anaesthesia Does Not Delay Early Postoperative Gastric Emptying in Man
Authors: Petring O. U. , Adelhöj B. , Erin‐Madsen J. , Angelo H. , Jelert H.
Published: January 2009

The effect of epidural anaesthesia on early postoperative gastric emptying was measured in seven patients, after minor surgery on the extremities. Gastric emptying, estimated indirectly by the rise in serum paracetamol following oral administration of the drug, was not delayed following epidural anaesthesia. It was furthermore demonstrated that gastric emptying was normal or nearly normal when diazepam 15 mg was given orally to the same patients 2 weeks later.
Enflurane, Isoflurane and the Eye
Authors: Earnshaw G.
Published: January 2009

The intra‐ocular pressure was monitored in ophthalmological patients in whom nitrous oxide/oxygen anaesthesia was supplemented with an inspired concentration of 1% enflurane (10 patients) or 0.7% isoflurane (10 patients). These concentrations are proportionate to 0.6 MAC in oxygen. Both agents caused a significant decrease in intra‐ocular pressure, enflurane by a mean of 3.1 mmHg (0.4 kPa) and isoflurane by 2.1 mmHg (0.3 kPa). There was no significant difference between agents. Isoflurane offers an alternative to enflurane in surgery when intra‐ocular pressure is of importance.
A New Method for Clinical Assessment of the Negative Inotropic Action of Anaesthetics ‐ With Special Reference to Isoflurane and its Effect on Myocardial Oxygenation
Authors: Reiz S. , Bålfors E. , Häggmark S. , Nyhman H.
Published: January 2009

A new method for maintaining the peripheral determinants of myocardial oxygen demand constant is described. Intravenously administered phenylephrine and nitroglycerin were used to control afterload and preload. Heart rate was kept constant with atrial pacing. The method was used to establish the in vivo negative inotropic effect of 1% end‐tidal isoflurane in eight patients with ischaemic heart disease during positive pressure ventilation (IPPV). Stroke volume measured during steady‐state isoflurane anaesthesia and IPPV with preload, afterload and heart rate kept constant was 23% below awake control. The decrease in myocardial oxygen consumption was 22% and correlated well (r = 0.891) with the fall in left ventricular performance (stroke volume).
Comparison of Three Hypotensive Anaesthetic Methods for Middle Ear Microsurgery
Authors: Saarnivaara L. , Brander P.
Published: January 2009

Three hypotensive anaesthetic methods were compared in 123 patients undergoing middle ear microsurgery. Hypotension was induced with halothane (1 vol. %), nitroprusside (4.4 μg/kg/min) or the combination of halothane (0.5 vol. %) and nitroprusside (1.2 μg/kg/min). The compensatory rise in the heart rate was controlled with a β‐adrenergic receptor blocking agent, practolol, the mean need for which was 0.03 mg/kg in the halothane group and 0.1 mg/kg in the other groups. The mean duration of the hypotensive period ranged from 79 to 107 min in the groups. During the hypotension, the average mean arterial pressure ranged from 55 to 60 mmHg (7.33 to 8.00 kPa) and the mean heart rate from 67 to 79 beats/min in the groups. The Pao2 value in the nitroprusside and halothane + nitroprusside groups, but not in the halothane group, decreased statistically and in some cases clinically significantly. The only peroperative side effects were ECG changes (mostly junctional rhythm), the incidence of which ranged from 16 to 24% in the groups. The mean values for the degree of haemostasis rated by the otologist on a visual analogue scale between poor (0 mm) and excellent (100 mm) were 90, 73 and 89 mm in the halothane, nitroprusside and halothane + nitroprusside groups, respectively. Recovery in the halothane group was statistically highly significantly longer than in the other groups. No rebound hypertension occurred in any of the groups after discontinuation of the hypotension. The most common side effect was nausea + vomiting, the incidence of which ranged from 15 to 26% in the groups. Respiratory difficulties occurred in 7% of the patients in the halothane group but not in the other groups. It is concluded that the hypotension induced either with halothane or halothane + nitroprusside produced good and similar operating conditions. Nitroprusside hypotension was inferior to the other methods since it produced statistically significantly worse haemostasis than the other methods, and the Pao2 value during hypotension decreased statistically significantly as also in the halothane + nitroprusside group. The disadvantage of halothane alone was long postanaesthetic recovery.
Effect of Vecuronium and Pancuronium on Cardiac Performance and Transmural Myocardial Perfusion During Ketamine Anaesthesia
Authors: Pedersen T. , Engbæk J. , øRding H. , Viby‐Mogensen J.
Published: January 2009

The haemodynamic effects of vecuronium and pancuronium were studied in 20 healthy patients during diazepam/ketamine anaesthesia. Anaesthesia was induced with glycopyrrolate 3 Hg/kg, diazepam 0.3 mg/kg and ketamine 1.0 mg/kg as a bolus and 1.0 mg/kg over 10 min. After induction, anaesthesia was maintained with ketamine infusion 1.0 mg/kg/h. The lungs were ventilated with 50% nitrous oxide in oxygen. Equipotent doses of vecuronium (74 μg/kg) or pancuronium (99 μg/kg) were administered for intubation. The thoracic impedance, ECG and phonocardiogram were recorded during the induction of anaesthesia. The results suggest that vecuronium has no cardiovascular effects during ketamine anaesthesia, whereas pancuronium due to its chronotropic effect, causes a deterioration in left ventricular performance.
Heat‐Induced Changes in P02 and Pco2 of Blood
Authors: Gøthgen I.
Published: January 2009

In vitro differences in blood P02 and Pco2 at 37d̀C and 42—44d̀C were measured in 100 samples from 10 patients, aged 54–79 years. P02 was measured amperometrically with Clark electrodes, Pco2 was measured with Severinghaus electrodes. P02 increased with heating and the relative P02 increment declined with increasing P02. At 10 kPa the relative increment was approximately 7% per d̀C; at 40 kPa it was less than 2% per d̀C. No correlation between the temperature coefficient and temperature, haemoglobin concentration or pH could be demonstrated. The observed changes were in agreement with the Severinghaus correction formula r = 0.99 (P<0.0001). Pco2 increased by 4.6% per d̀C (s.d. = 0.8%) with heating. The Pco2 temperature coefficient did not vary significantly with the Pco2, pH or temperature (P>0.3). No significant difference was seen between the measured values and values calculated according to Severinghaus and Nunn et al. (4.4% per d̀C) or Siggaard‐Andersen (4.8% per d̀C), r = 0.95 (P< 0.0001). It is concluded that the recommended temperature correction formulas for P02 and Pco2 changes in the blood can be applied even in the temperature level 37–44d̀C, and thus for analysis of P02 and Pco2 on the heated skin surface.
Dose‐Response of Tubocurarine in Patients With and Without Renal Failure
Authors: Orko R. , Heino A. , Rosenberg P. H. , Alanen T.
Published: January 2009

Different initial doses of tubocurarine (0.1, 0.2, 0.3 and 0.4 mg kg‐1) were given to 20 patients with and 20 patients without renal failure (RF) during standard anaesthesia. Neuromuscular blockade was registered with a device based on electromyography. A fluorescent technique was used to measure plasma tubocurarine concentrations, for which blood samples were drawn during induction and at reversal of neuromuscular block. The dose‐response curves for the induction period were slightly steeper in patients with RF. A linear correlation between tubocurarine concentration and twitch response was found in both groups, although the curve had shifted to the left in RF patients. The total amount of tubocurarine used for surgical relaxation was lower in the RF than in the non‐RF patients.
The Response of the Awake Spontaneously Hypertensive Rat (SHR) to Acute Blood Loss
Authors: Wennberg E. , Hagberg H. , Haljamäe H.
Published: January 2009

In order to evaluate experimentally if the presence of hypertensive disease is an additional risk factor in connection with emergency situations including blood loss, awake spontaneously hypertensive rats (SHR) and normotensive Wistar‐Kyoto rats (WKY) were subjected to standardized acute haemorrhage (35% of blood volume) via an aortic catheter. Mean arterial blood pressure (MAP), blood gases, acid‐base balance, blood glucose and haematocrit values were followed and the 5‐h survival rate was determined. In the early posthaemorrhagic phase similar plasma refill, as evidenced from haematocrit readings, was seen in SHR and WKY. Hyperglycaemia occurred in both groups but the hyperglycaemic response was only moderate and transient in SHR. The inability of SHR to maintain hyperglycaemia was intimately correlated to early appearance of metabolic acidosis and short posthaemorrhagic survival times. Determination of liver glycogen content of unbled SHR and WKY indicated that the deficient hyperglycaemic response in SHR was not due to inadequate glycogen stores but rather to poor liver perfusion resulting in liver hypoxia. Since spontaneous hypertension in rats in many ways is considered to be similar to essential hypertension in man, these findings suggest that human hypertensive disease constitutes a considerable risk factor in connection with acute haemorrhage.
Gas Exchange During Ventilator Treatment: a Validation of a Computerized Technique and its Comparison With the Douglas Bag Method
Authors: Bredbagka S. , Kawachi S. , Norlander O. , Kirk B.
Published: January 2009

In recent years a number of commercial instruments for on‐line gas exchange measurements has been introduced. One of them, the Engström Metabolic Computer (EMC), is here clinically validated as compared to the standard Douglas bag method for gas sampling and a Centronic Mass Spectrometer (CMS) for gas analysis. Vo2, Vco2 and RQ were simultaneously measured and calculated with both methods. Twenty individual gas exchange determinations were made at different times on 12 critically III patients at the intensive care unit. There was a small but significant difference (P< 0.025) of 4.3% ± 8.4% (s.d.) between the two methods when they were used to measure V02 (the EMC giving the lower value). The corresponding value of Vco2 was 2.4% ±9.1% (s.d.), and for RQ the difference was ‐1.98% ±7.1% (s.d.). These differences are not significant at the 95% level of significance. Determinations of oxygen uptake during ventilator treatment with standard methods usually involve technical difficulties and are associated with errors of method around 10%. Our results indicate a probable error of about 8.5% for V02 in clinical situations. Considering the difficulties involved in determinations of gas exchange, the EMC method seems to be a valuable technique with an accuracy within acceptable limits.
Peroperative Hypothermia
Authors: Tølløfsrud S. G. , Gundersen Y. , Andersen R.
Published: January 2009

Heat loss during anesthesia and operation and subsequent hypothermia will increase the postoperative oxygen demand and may endanger patients with restricted cardiopulmonary reserves. Forty patients scheduled for intra‐abdominal aortic surgery and 40 patients scheduled for peripheral vascular surgery on the lower limbs were investigated using a warming blanket, humidified heated inspired anesthetic gases at 37–40d̀ C, or both these methods together. A fourth group of patients received no active warming. A warming blanket used alone gave no protection against hypothermia when compared with no active warming. In the abdominal surgical group, there was a steady fall in temperature throughout the operation if no warming method was employed. In this group the use of humidified, heated inspired gases was significantly better than no treatment after 2 h of anesthesia (P < 0.05). The combination of humidified and heated inspired gases and a warming blanket gave significantly better heat preservation after 40 min (P < 0.05). Patients undergoing peripheral vascular surgery had similar but smaller drops in temperature with the different types of wanning procedures employed. The differences in temperature between the intra‐abdominal and extra‐abdominal operations were statistically significant after 3 h (P < 0.05).
Effects of Succinylcholine Chloride on the Response of Fast and Slow Muscle in the Cat
Authors: Choi W. W. , Gergis S. D. , Sokoll M. D.
Published: January 2009

Fast and slow muscle fibres differ histochemically, electrophysiologically and pharmacologically.In vivo, the effect of 0.05, 0.075 and 0.1 mg . kg‐1succinylcholine on the response of the indirectly stimulated gastrocnemius (fast) and soleus muscle (slow) to single, train‐of‐four and tetanic stimuli was studied. There was a significant difference between the response of the two muscles. Maximum twitch suppression occurred 2 min after injection and was more significant in the gastrocnemius than the soleus. The duration of the neuromuscular blockade was 9 min or more in both groups. The train‐of‐four ratio dropped below 0.7 in the gastrocnemius preparation at all doses and in the soleus when 0.1 mg‐kg‐1succinylcholine was used. Sustained tetanus was achieved in both muscles at 5 and 10 min, respectively. There was evidence of fatigue in the soleus muscle at the 5‐min observation suggestive of the presence of a phase II block, a phenomenon not observed in the gastrocnemius.
Lateral Positioning With Differential Lung Ventilation and Unilateral PEEP Following Unilateral Acid Aspiration in the Dog
Authors: East T. D. , Pace N. L. , Westenskow D. R.
Published: January 2009

Body position can significantly alter the efficiency of gas exchange following unilateral lung injury. We systematically examined three positions during differential lung ventilation with unilateral positive end‐expiratory pressure (PEEP) following unilateral hydrochloric acid aspiration in the dog. Twelve mongrel dogs were intubated with a double‐lumen endobronchial tube and mechanically ventilated with a microcomputer‐controlled pair of ventilators. A tidal volume of 7.5 ml/kg was delivered to each lung. The Paco2 was maintained at 4.67 kPa. A unilateral injury was induced with an injection of 0.1 N hydrochloric acid (2.5 ml/kg) into one lumen of the endobronchial tube. 0.984 kPa PEEP was applied to the injured lung and the dogs were placed sequentially in one of three positions (supine, lateral decubitus with injured lung non‐dependent, and lateral decubitus with injured lung dependent) for 1 h apiece. There was no significant difference between the three positions with regard to Pao2 (F (2, 10) = 1.60, P = 0.25) or venous admixture (F (2, 10) = 0.49, P = 0.63). Our data indicated that position did not alter oxygenation. This was probably due to the use of differential ventilation with unilateral PEEP which eliminated redistribution of ventilation between the two lungs and minimized position‐dependent changes in pulmonary blood flow.
Rectal Administration of Morphine Hydrogel: Absorption and Bioavailability in Women
Authors: Westerling D. , Andersson K. E.
Published: January 2009

Seven patients undergoing radiological treatment for carcinoma of the uterus were given morphine intramuscularly (0.15 mg kg‐1) and morphine in a starch hydrogel rectally (0.56 mg kg‐1) on two separate occasions. The hydrogel preparation was used in order to improve the contact between the rectal mucosa and thus improve and possibly prolong the absorption of morphine. Plasma concentrations of morphine were followed for 8 h and analysed with a GG/MS technique. It was found that 45–120 min after administration of morphine hydrogel, a mean maximum plasma morphine concentration of 61 ngml‐1 was obtained. After 8 h, the mean plasma concentration was 10 ngml‐1. The mean biological availability of morphine hydrogel was 48% (range 31–72%). It is suggested that morphine hydrogel, given rectally, can be clinically useful.
Haemodynamic Effects of Fentanyl or Alfentanil as Adjuvants to Etomidate for Induction of Anaesthesia in Cardiac Patients
Authors: Spiss C. K. , Coraim F. , Haider W. , White P. F.
Published: January 2009

This investigation was designed to study the comparative haemodynamic effects of alfentanil, 5 mg vs. fentanyl 0.5 mg when administered in combination with etomidate for induction of anaesthesia in patients undergoing cardiac surgery. Both groups manifested significant decreases in heart rate (17–22%), cardiac index (12–25%) and mean pulmonary artery pressure (4—17%). The mean arterial pressure was decreased in both groups; however, the decrease was significantly greater in the alfentanil group. In contrast to the fentanyl group, the systemic vascular resistance was transiently decreased in the alfentanil group. In conclusion, it appears that alfentanil is associated with a greater degree of cardiovascular depression than fentanyl when used in combination with etomidate as part of an induction sequence in cardiac surgery patients.
Cardiovascular Response to Endotracheal Intubation During Four Anesthetic Techniques
Authors: Bedford R. F. , Marshall W. K.
Published: January 2009

In order to investigate the impact of four different anesthetic regimens on the cardiovascular response to endotracheal intubation, 24 patients were anesthetized to approximately the same depth of anesthesia (MAC‐fraction) using one of four supplements to N2O‐O2 (60:40) anesthesia: Group 1 = morphine 0.5 mg/kg i.v., Group 2 = Innovarr̀ 0.1 ml/kg i.v., Group 3 = halothane, 0.4% end‐tidal, Group 4 = enflurane 0.7% end‐tidal. Cardiovascular variables were recorded from radial arterial and thermistor‐tipped pulmonary artery catheters and were determined at the following times: (1) while the patients were awake prior to induction of anesthesia; (2) after a stable level of anesthesia had been induced; and (3) within the first minute after endotracheal intubation. Only the groups receiving morphine and halothane sustained significant increases in heart rate, rate pressure product and pulmonary capillary wedge pressure after intubation. It is concluded that N2O‐O2 anesthesia supplemented with either morphine or halothane at the 1 MAC dose level does not adequately prevent cardiovascular response after endotracheal intubation, and that these techniques require additional anesthetic depth or other adjuvant drugs in order to prevent cardiovascular complications.
Can the “Sympatho‐Galvanic Reflex” (Skin Conductance Response) Be Used to Evaluate the Extent of Sympathetic Block in Spinal Analgesia?
Authors: Löfström J. B. , Malmqvist L. Å. , Bengtsson M.
Published: January 2009

The skin conductance response (SCR) (the “sympatho‐galvanic reflex”) was studied in volunteers and in a few patients undergoing spinal analgesia. Electrical stimulation over the clavicle, breath‐holding during inspiration, a short, deep breath and a sharp sound provoked a marked change in conductance not only in the hand and foot but also in dermatomes T5, T9, T12‐L1. Thus, the SC response can be used to study sympathetic activity not only in the hand and foot, but also on the chest and abdomen. Electrical stimulation over the clavicle or a short, deep breath were the best means of provoking SC responses in patients receiving spinal analgesia. This restricted pilot study indicates that skin conductance response is maintained at dermatome levels far below anaesthetised levels during spinal analgesia, and a larger study is now under way to investigate these results further.
Influence of Blood‐Taking Procedure on the Heart Function of Blood Donors
Authors: Ibler M. , Lage S.
Published: January 2009

The systolic time intervals and heart rate were studied in 11 blood‐donors aged between 20 and 48 years by a non‐invasive technique before and after the usual blood‐taking procedure. No statistically significant difference was found between values determined before and after the procedure. A significant correlation (r = 0.76) was demonstrated between percent changes of pre‐ejection period/left ventricular ejection time (PEP/LVET)‐ratio and withdrawn volume of blood (450 ml) × time (min)‐1 × bodyweight (kg)‐1. No correlation was found between percent changes of PEP/LVET‐ratio and withdrawn volume of blood × time‐1, nor between percent changes of PEP/LVET‐ratio and withdrawn volume of blood × percentage of circulatory volume removed‐1. It is suggested that the blood‐taking time (in minutes) should not be shorter than the quotient: donated volume of blood (ml) × bodyweight (kg)‐1 if a negative influence of withdrawal procedure on left ventricular function is to be avoided. Mechanisms contributing to circulatory stability during reduction of blood volume are briefly discussed.
Moisture Exchangers Do Not Prevent Patient Contamination of Ventilators. A Microbiological Study
Authors: Bygdeman S. , Euler C. von , Nystrom B.
Published: January 2009

Thirty‐three mechanically ventilated patients in an intensive care unit were studied in order to verify a claim that the Servo humidifier acts as a bacterial barrier. The Servo humidifier was used on all patients. It was changed once daily, and the connecting tubes were changed once weekly. Daily bacterial cultures were taken from the trachea of the patient as well as from the humidifier, the tubing and the ventilator. In 25 of the patients, the same bacterial strain as in the trachea of the patient could not be isolated from the outside of the humidifier, from the tubing or the ventilator. In eight patients a breakthrough of bacterial strains from the trachea through the humidifier could be demonstrated. In four of these eight patients the breakthrough strains appeared to establish themselves in the respirator environment, while in the other four they appeared only temporarily outside the humidifier. The clinical importance of the establishment of a bacterial strain in the ventilator is not clear, but it seems prudent that the introduction of the Servo humidifier should not lead to less stringent cleaning and/or disinfection routines of ventilators and tubing than before.
Perivascular Axillary Block V: Blockade following 60 ml of Mepivacaine 1 % Injected as a Bolus or as 30 + 30 ml with a 20‐min Interval
Authors: Vester‐Andersen T. , Husum B. , Lindeburg T. , Borrits L. , Gøthgen I.
Published: January 2009

Perivascular axillary blockade was performed on 60 patients with the aid of a catheter technique. The patients were randomly allocated to two groups. All patients received the same dose of local anaesthetic: 60 ml of mepivacaine 1 % with adrenaline, but one group received the dose as a bolus injection, whereas the other group received the dose as fractional injections of 30 + 30 ml with an interval of 20 min. Blood concentrations of mepivacaine were measured up to 90 min after injection of local anaesthetic. Sensory and motor blockade were evaluated 20, 30 and 40 min after injection. Forty minutes after the last injection of local anaesthetic, there was no difference between the blockades of the two groups, except for the sensory blockade of the lower lateral cutaneous nerve of the arm, in which the frequency of analgesia was 90% after bolus injection and 63% after fractional injections. There was no difference in blood concentrations of mepivacaine between the two groups. None of the 60 patients showed any sign of systemic toxic reactions. Fractional injection of local anaesthetic in perivascular axillary blockade does not offer any advantage over bolus injection with regard to the resulting blockade.
Enkephalinase Inhibition Prevented Tolerance to Nitrous Oxide Analgesia in Rats
Authors: Rupreht J. , Ukponmwan O. E. , Dworacek B. , Admiraal P. V. , Dzoljic M. R.
Published: January 2009

Tolerance to nitrous oxide (N2O) antinociception was studied in rats in accordance with the Randall‐Selitto pressure nociception test. Both N2O (70% in 30% O2) and the relatively selective enkephalinase inhibitor phosphoramidon (350 μg i.c.v.), which blocks the biotransformation of enkephalins, were administered. They both induced a significant analgesic effect which vanished within 45 min. The rapidly developed tolerance to N2O analgesia does not affect the anaesthetic state since the animals remained motionless for the duration of exposure lasting 3 h. In the animals treated with the enkephalinase inhibitor phosphoramidon, no development of tolerance to N2O‐antinociception occurred during the exposure lasting 3 h. The results indicate that tolerance to N2O analgesia can be abolished by activation of the enkephalinergic system, which might suggest a possible insufficiency of this system during tolerance to N2O.
Intravenous Sedation for the Intubated and Spontaneously Breathing Patient in the Intensive Care Unit
Authors: Bird T. M. , Edbrooke D. L. , Newby D. M. , Hebron B. S.
Published: January 2009

A technique is described for the management of post‐operative patients who have undergone major cranio‐facial surgery. Under supervision on the Intensive Care Unit, the patients breathe humidified, oxygen‐enriched air through a naso‐tracheal tube. Sedation and analgesia are provided by continuous infusions of etomidate (variable rate) and fentanyl (fixed rate), administered by volumetric infusion pumps (IMED 922). Six patients have been studied in detail and our results are presented. In conjunction with fentanyl, a mean infusion rate of 3.72 μg+ kg‐1 min‐1 of etomidate provided good sedation and analgesia, without clinically significant respiratory depression. The patients found the technique very acceptable and no side‐effects were noted.
Rectal Diazepam Compared to Intramuscular Pethidine/Promethazine/Chlorpromazine with Regard to Gastric Contents in Paediatric Anaesthesia
Authors: Blom H. , Schmidt J. F. , Rytlander M.
Published: January 2009

Sixty children, aged 1—12 years, were investigated with regard to gastric pH and volume before general anaesthesia. Thirty children (group D) received diazepam 0.75 mg/kg b.w. rectally 1 h before anaesthesia. Thirty children (group L) received a “lytic cocktail” (pethidine 28 mg, promethazine 7 mg, chlorpromazine 7 mg per ml) 0.05 ml/kg b.w. intramuscularly 1 h before anaesthesia. The pH values were significantly higher and the amount of gastric juice was significantly lower in group L compared to group D. The number of children in group L with gastric juice volume exceeding 0.4 ml/kg and the number of children with pH less than 2.5 was significantly smaller compared to group D. The number of children with both gastric pH less than 2.5 and gastric juice volume greater than 0.4 ml/kg was significantly smaller in the group receiving “lytic cocktail” intramuscularly compared to the group receiving diazepam rectally. Bile‐stained gastric contents was not related to the gastric pH.
Distribution of Expiratory Gas and Rebreathing in a T‐piece Modification Combined with a PEEP Valve
Authors: Hartmann‐Andersen F. , Andersen P. K. , Olsen J. E. , Jakubaszko J.
Published: January 2009

T‐piece modifications with PEEP valves are often used in weaning from mechanical ventilation or for intubated patients not requiring ventilatory support. Distribution of expiratory gas and the extent of rebreathing in a T‐piece modified with an inspiratory reservoir (ICR) and with a PEEP valve were studied in a model with various fresh gas flows (FGF), tidal volumes and frequencies at three valve settings: 0 cmH2O (ZEEP) and PEEP of 5 and 10 cmH2O (0.490–0.981 kPa). Two types of distribution of expiratory gas were delineated: type one with expiratory gas in the inspiratory limb (IL) and a high ratio of the maximum CO2 content and corresponding end‐expiratory CO2 concentration in the expiratory limb (EL) (FmaxCO2/F2CC2) and a type 2 with no detectable alveolar gas in the IL and a low ratio of FmaxGO2/FECO2. The use of PEEP did not increase the amount of alveolar gas in the system, and no increase occurred in the end‐expiratory CO2 concentration. The investigated system is in fact a Mapleson A system. The ratio of FGF to minute ventilation just preventing rebreathing during spontaneous ventilation is approximately 1, in contrast to 3 in other modifications. These advantages minimize the risk of rebreathing, even when the minute ventilation rises to that of the fresh gas flow. The T‐system with a compliant inspiratory reservoir and a PEEP valve can, in most clinical weaning situations, satisfy the inspiratory peak flow of different respiratory patterns with a standard FGF of 15 1 × min‐1.
Metoprolol Medication and Coronary Artery Bypass Grafting Operation
Authors: Heikkilä H. , Jalonen J. , Laaksonen V. , Arola M. , Oja R.
Published: January 2009

Twenty patients undergoing a coronary artery bypass grafting operation with high‐dose fentanyl anaesthesia, all on long‐term metoprolol medication, were randomly divided into a metoprolol group (last metoprolol dose given 1.5 h before the anaesthesia) and a control group (last metoprolol dose 12 h before the anaesthesia). Haemodynamics were measured and the ECG was recorded serially in order to compare the responses to the anaesthesia induction and skin incision in these two groups and to evaluate possible harmful effects of the maintained metoprolol medication. The ECG showed ischaemic signs in five control group patients during the anaesthesia induction; these patients also had a relatively high rate‐pressure product. No metoprolol group patient developed ECG changes indicative of ischaemia at this stage, despite a low plasma metoprolol concentration in two patients. Surgical stimulation caused no signs of myocardial ischaemia in either group. There were no inter‐group differences in the haemodynamics or oxygen transportation. No harmful effects of the maintained metoprolol on the post‐bypass cardiac performance nor on the occurrence of rhythm or conduction disturbances could be seen, although a high plasma metoprolol concentration was maintained in several metoprolol group patients over the bypass time. It is concluded that continuation of long‐term metoprolol medication up to 1.5 h before high‐dose fentanyl anaesthesia for coronary artery bypass grafting has no harmful effects on the haemodynamics during the operation or the restoration of the cardiac function after the cardiopulmonary bypass, but it evidently does help to maintain the myocardial oxygen supply/ demand balance during the anaesthesia induction.
Midazolam as Adjunct to High‐Dose Fentanyl Anaesthesia for Coronary Artery Bypass Grafting Operation
Authors: Heikkilä H. , Jalonen J. , Arola M. , Kanto J. , Laaksonen V.
Published: January 2009

The usefulness of midazolam as an adjunct during high‐dose fentanyl anaesthesia was studied by following the changes in the haemodynamics and total body oxygenation after an intravenous injection of 0.075 mg/ kg and 0.15 mg/kg of midazolam during the induction of fentanyl (75 μg/kg)‐oxygen anaesthesia for a coronary artery bypass operation. These responses were then compared to the changes seen in patients receiving the same fentanyl anaesthesia without the midazolam. A rapid decline after the midazolam injection was seen in the mean systemic arterial pressure (24—32% ‐ the lowest individual value was 45 mmHg (6.0 kPa)) and in the systolic and diastolic pulmonary arterial pressures (29–33% and 30–31%) in 1–3 min. As measured 10 min after the midazolam injection, a decrease from the baseline was seen in the stroke index (25–30%), in the left ventricular stroke work index (46–42%) and in the right ventricular stroke work index (48–61%). These haemodynamic variables remained on a lower level throughout the study period (40 min) in the midazolam patients as compared to the controls. The tissue oxygenation seemed to be sufficient in all groups during the study period. An intravenous injection of a relatively low dose of midazolam during the induction of high‐dose fentanyl anaesthesia seems to be followed by rapidly increased venous pooling and a moderately to severely decreased systemic arterial pressure. Based on the results of this study, midazolam cannot be recommended as an adjunct during high‐dose fentanyl anaesthesia.
The Measurement of Tidal Volumes in Spontaneously Breathing Children during General Anaesthesia using a Haloscale Infant Wright Respirometer
Authors: Meeke R. , Wren W. , Davenport J. , O'Griofa P.
Published: January 2009

The accuracy of tidal volume measurements made with a Wright Haloscale infant respirometer in children breathing spontaneously during general anaesthesia was assessed by a bench test. The tidal volumes and peak flow rales of 20 spontaneously breathing, anaesthetised children were measured with a pneumotacho‐graph before and during surgery, and similar volumes, at the same flow rates, were delivered by a calibrated syringe simultaneously to the respirometer and a pneumotachograph. The results reveal that the mean (+ s.d.) peak gas flow rates of children aged 6 years and less, 7.5 (± 1.6) and 9.3 (±0.1) 1/min before surgery and during surgery respectively, are significantly less than the peak flow rates, 11.3 (± 1.0) and 11.9 (+ 1.5) before and during surgery, respectively, of children aged more than 6 years; and that the respirometer underestimates tidal volume by 10% when the peak flow rate is 11 1/min, and the percentage error in tidal volume estimation by the respirometer increases as the peak gas flow declines below 10 1/min.
Comparison of Fentanyl and Halothane as Supplement to Nitrous‐Oxide‐Oxygen Anaesthesia for Coronary Artery Surgery
Authors: FISCHERSTRÖM A. , ÖHQVIST G. , SETTERGREN G.
Published: January 2009

Twenty unselected patients suffering from incapacitating angina, in spite of medication with nitrates, β‐ blockers and calcium antagonists, were studied before and during coronary artery bypass surgery. Fentanyl or halothane was randomly used in combination with nitrous oxide for maintenance of anaesthesia in order to compare the haemodynamic response to surgery and cardiopulmonary bypass with these two anaesthetic regimens. Systemic and pulmonary artery pressure were kept within normal limits with the aid of volume replacement and/or nitroprusside. The haemodynamic response to surgery and bypass was benign and almost identical in the two groups. Cardiac index increased markedly after bypass (P<0.02–0.001) from 2.0 to 3.0 1 ⋅ min‐1 × m‐2 due to an increase in heart rate with no change in stroke index (40 ml ⋅ m‐2). Oxygen delivery remained unchanged at 17 mmol ⋅ min‐1 ⋅ m‐2 in spite of a marked reduction in blood erythrocyte volume fraction (B‐EVF), from 38% before bypass to 24% after bypass (P<0.001). Oxygen uptake remained unchanged until the end of surgery and did not differ between the groups. Systemic vascular resistance, corrected for the change in viscosity due to the altered B‐EVF, was unchanged during the study. No difference was observed between the groups in the relation between pulmonary artery diastolic pressure and left ventricular stroke work index or stroke index, either before or at the end of cardiopulmonary bypass when the patients were transfused from the oxygenator.
Circulatory Effects of Pancuronium and Alcuronium in Patients with Coronary Artery Stenosis
Authors: ÖHQVIST G. , SETTERGREN G. , TUPPURAINEN T. , LINDSKOG E. ANJOU , FISCHERSTRÖM A. , TORSSELL L. , WEDELIN B. , WICKERTS C. J.
Published: January 2009

Heart rate and systemic arterial blood pressure were recorded during induction of anaesthesia up to 9 min after endotracheal intubation in 92 patients scheduled for coronary artery bypass surgery, in order to study to what degree the circulatory response to induction of anaesthesia and intubation was modified by different relaxants. Pancuronium (pancuronium bromide) 0.1 mg ⋅ kg b. w.‐1 and alcuronium (diallyl‐nortoxiferine) 0.25 mg ⋅ kg b. w.‐1 were randomly studied in 36 patients during induction with high‐dose fentanyl and in 36 patients induced with thiopentone, diazepam, fentanyl and nitrous oxide. In patients given high‐dose fentanyl anaesthesia, systolic blood pressure before, during and after intubation was significantly lower with alcuronium (P<0.01). The same difference between alcuronium and pancuronium was observed in balanced anaesthesia before endotracheal intubation. Induction of anaesthesia and intubation were followed by a moderate increase in heart rate, irrespective of the type of anaesthesia and relaxant. Subsequently, 20 patients (10 with high‐dose fentanyl and 10 with balanced anaesthesia) were studied. They received pancuronium 0.05 mg ⋅ kg b. w.‐1 +alcuronium 0.125 mg ⋅ kg b. w.‐1. This mixture of relaxants produced an intermediate blood pressure response.
Phosphate Supplementation in Parenteral Nutrition
Authors: PIGON J. , LINDHOLM M. , EKLUND J. , HAGELBÄCK A.
Published: January 2009

Pronounced serum phosphate deficiency has been shown to be deleterious when starting parenteral nutrition in severely malnourished patients. The consequences of phosphate deficiency and the need for phosphate supplementation in critically ill patients are not well known. Thirty ICU patients randomized into two groups were studied. The patients received complete parenteral nutrition with and without addition of extra phosphate. The low phosphate group got 7.5 mmol phosphate (from the phospholipids in the fat emulsion) and the high phosphate group got 60–80 mmol phosphate/day. There were no significant differences in serum phosphate or calcium levels between the groups. In the high phosphate group the phosphate balance was positive and calcium balance zero while in the low phosphate group both phosphate and calcium balances were negative. The phosphate content in a standard nutrition programme is not sufficient to create a positive phosphate balance. With the addition of 80 mmol phosphate/day a positive balance was achieved. It is hard to establish guidelines for the administration of phosphate in ICU patients. 20–40 mmol may normally be satisfactory but we have shown that ICU patients may need and can tolerate up to 80 mmol/ day.
A Comparison of Bupivacaine and Tetracaine in Spinal Anaesthesia with Special Reference to Motor Block
Authors: AXELSSON K. , WIDMAN G. B.
Published: January 2009

Thirty‐six patients received spinal anaesthesia with either glucose‐free bupivacaine (22.5 mg) or glucosecontaining solutions of bupivacaine (20 mg) or tetracaine (15 mg). The duration of analgesia in the lower thoracic and lumbar segments was significantly longer with glucose‐free bupivacaine than with the other solutions. Using a quantitative method for measuring muscle strength, the motor block was recorded for three types of movements: hip flexion, knee extension and plantar flexion of the big toe. Movements of the lower part of the thoracic cage were recorded at the same time. The length of time from spinal injection to complete motor block was short and without notable difference between all three groups. Regression of the motor block tended to start earlier for hip flexion and knee extension than for plantar flexion of the big toe. For all three movements the regression of the motor block began significantly later in the glucose‐free bupivacaine group than in the other groups. During the regression phase, muscle strength returned significantly later in the glucose‐free bupivacaine group than in the bupivacaine group containing glucose and knee extension returned significantly later in the glucose‐free bupivacaine group than in the tetracaine group. No difference in motor block was found between the hyperbaric solutions of bupivacaine and tetracaine. For hip flexion (L1‐L3), there was no noteworthy difference between the level of analgesia and the motor block segments, whereas for plantar flexion of the big toe (L5‐S2) the level of analgesia lay 2–3 segments higher than the motor block segments. In seven patients, during spinal anaesthesia there was a reduction in respiratory deflections corresponding to the lower thorax. As the Bromage scale only represented the motor block during the first half of the regression phase, it was of limited value. As measured according to the Bromage scale, the patients could not be mobilized until 1–2 h after complete restoration of the muscle strength.
Adrenergic Hyperactivity and Epidural Block in Severe Tetanus A Case Report
Authors: LINDAHL S. G. E. , DAHLGREN N. , LUNDBERG D. , NORDÉN N.
Published: January 2009

In a 69‐year‐old man with severe tetanus, sympatho‐adrenal overactivity was successfully treated with a lumbar epidural block. Cardiovascular disturbances were reduced and fluctuations in plasma catecholamines were decreased. The duration of other manifestations of tetanus was, however, not influenced by the epidural block in this case.
Cardiovascular Studies during Controlled Baroreflex Activation in the Dog: I. Effects of Enflurane
Authors: HENRIKSSON B.‐Å. , BIBER B. , MARTNER J. , PONTÉN J. , WERNER O.
Published: January 2009

In chloralose‐anaesthetized dogs the carotid sinuses were bilaterally perfused with blood from a femoral artery, either at systemic arterial pressure through a direct by‐pass or with a pump in order to control the sinus pressure. Influences from cardiac receptors and aortic baroreceptors were eliminated by denervation. Administration of enflurane (1.6% end‐tidal concentration) with the presence of barostatic modulation, i. e. the carotid sinuses were perfused at prevailing systemic arterial pressure, reduced cardiac performance (cardiac output, cardiac contractility, heart rate and left ventricular stroke work) and mean arterial pressure. When barostatic compensation of enflurane‐induced circulatory changes was prevented by maintaining sinus perfusion pressure constant at the pre‐enflurane level, these haemodynamic alterations, with the exception of cardiac output, were significantly more pronounced. Furthermore, systemic vascular resistance decreased. We conclude that barostatic reflexes significantly modify cardiovascular depressive effects of enflurane.
Coronary Haemodynamic Effects of Surgery during Enflurane‐Nitrous Oxide Anaesthesia in Patients with Ischaemic Heart Disease
Authors: REIZ S. , RYDVALL A. , HÄGGMARK S.
Published: January 2009

The systemic and coronary haemodynamic effects of 1.5 MAC enflurane‐nitrous oxide anaesthesia and abdominal surgery were investigated in nine patients with ischaemic heart disease. Anaesthesia decreased systemic blood pressure (‐ 56%) by a combination of cardiodepression and peripheral vasodilation. A marked fall in myocardial oxygen extraction suggested a moderate coronary vasodilation. Surgery markedly increased the circulating levels of adrenaline and noradrenaline, manifested by increases in blood pressure (+ 76%) and systemic vascular resistance (+ 83%). Pulmonary capillary wedge pressure increased by 70% without any change in cardiac or stroke volume index, suggesting that the patients were performing at the horizontal part of their left ventricular function curve. Despite the marked rise in coronary perfusion pressure and a 62% increase in myocardial oxygen demand, coronary blood flow remained unaltered. This could be due either to coronary vasoconstriction overriding the normal coronary autoregulation or to an increase in coronary back pressure opposing the diastolic aortic pressure. When coronary blood flow could not increase to meet the demand for oxygen, the myocardium had to extract more oxygen to ensure appropriate oxygenation, demonstrating interference with coronary autoregulation. Surgery markedly increased myocardial extraction of adrenaline and noradrenaline. We could not find any relationship between myocardial adrenaline extraction and heart rate response to surgery or between myocardial noradrenaline extraction and changes in coronary blood flow, calculated coronary vascular resistance, incidence of myocardial ischaemia or cardiac dysrhythmias.