bluuebunny/crossref_metadata_2025 huggingface dataset:
Anaesthesia Induction and Lower Oesophageal Sphincter Pressure
Authors: Laitinen S. , Mokka R. E. M. , Valanne J. V. I. , Larmi T. K. I.
Published: January 2009

The effects of some drugs generally used in premedication for and induction of anaesthesia on the lower oesophageal sphincter (LOS) pressure were investigated in 30 dogs, using the modern oesophageal manometric technique. In thiopental‐induced anaesthesia, a distinct pressure gradient was noted between the LOS and gastric pressure. Atropine eliminated this pressure gradient almost completely. Metoclopramide increased the LOS pressure significantly, and subsequent atropine administration was unable to bring it down. Metoclopramide administered after atropine was unable to elevate the LOS pressure reduced by atropine. Succinylcholine had no observable lasting effect on the LOS pressure.

The present findings seem to indicate that of the drugs generally used in premedication for and induction of anaesthesia, atropine significantly reduces the LOS competence, thereby creating favourable conditions for gastro‐oesophageal reflux (GOR) and consequent postoperative pulmonary complications. Use of metoclopramide in premedication for or induction of anaesthesia to eliminate the depressant effect of atropine on the LOS pressure appears to be indicated.
Comparative Evaluation of Neuro‐Muscular Blockade after Pancuronium Administration in Patients with and without Renal Failure
Authors: Dhollander A. A. , Camu F. , Sanders M.
Published: January 2009

Objective studies about the duration of action of pancuronium (PCM) in renal failure patients are scarce. This study was undertaken to obtain more complete information on spontaneous reversal from PCM‐induced neuromuscular block by monitoring the twitch height to full recovery in the absence of any potentiating agent. Thumb abduction was monitored by a deplacement transducer in end‐stage renal failure (ESRF) and in control patients without renal failure (RF) during neuroleptanalgesia after 0.04 mg/kg and 0.08 mg/kg PCM administration.

In the small dosage series, the prolongation of action in ESRF becomes significant for the 75% recovery level (mean values ± s. e. mean:control: 42±7 min, ESRF: 71±10 min, P≤0.05). In the second series (0.08 mg/kg), the 50% recovery level is already significantly delayed in ESRF patients (control: 91±7 min, ESRF: 163±27 min, P≤0.05). The 100% twitch height recovery is obtained with 0.04 mg/kg PCM within 65 f 7 min for patients without RF and within 103±9 min in ESRF patients (P≤0.01). For the 0.08 mg/kg PCM dose, these figures are, respectively, 139±9 min and 214±20 min (P≤0.01).

The prolongation of PCM action in ESRF is in agreement with the pharmacokinetics of the drug. Large dosages of PCM must be avoided in ESRF patients because it delays spontaneous full recovery for too long.
Operating Room Nurses' Psychomotor and Driving Skills after Occupational Exposure to Halothane and Nitrous Oxide
Authors: Korttila K. , Pfäffli P. , Linnoila M. , Blomgren E. , Hänninen H. , Häkkinen S.
Published: January 2009

Concentrations of halothane and nitrous oxide were assayed by gas chromato‐graphy throughout a working day in three operating theatres and in the end‐tidal air of 19 nurses 15 and 60 min after leaving the theatres. Perceptual, psychomotor and driving skills were measured in these nurses and in 11 younger nurses working in the wards of the same hospital. A complicated psychomotor test battery and a driving simulator were used. End‐tidal air concentrations of halothane and nitrous oxide were positively correlated with the exposure level of these gases in the operating theatres. Some of the operating room nurses had greater amounts of halothane in their end‐tidal air (average 15 to 10 ppm) than student volunteers 4.5 h after 3.5 min of general anaesthesia with a combination of halothane‐nitrous‐oxide‐oxygen (10 ppm halothane). These volunteers had worse psychomotor and driving performances when measured than controls who had not been anaesthetized. No correlations were found between the concentrations of halothane or nitrous oxide in end‐tidal air and psychomotor or driving performance. Despite their higher age and exposure to the operating room environment, the driving skills of the operating room nurses were similar to those of the ward nurses. The results suggest that tolerance to anaesthetic gases develops among operating room personnel. No impairment of driving skills can be expected after daily exposure to halothane and nitrous oxide among long‐term employees in operating theatres.
Concentration and Elimination of Anaesthetic Gases in Recovery Rooms
Authors: Berner Ole
Published: January 2009

The investigation includes the measurement of the N2O‐concentration in the recovery rooms of three hospitals with different room ventilation systems. The amount of ventilation determines the elimination of the gas exhaled by the patients and, therefore, is related to the number of patients in the recovery rooms.

The investigation has shown that non‐recirculating room ventilation of 500 m3/ pt./hour in recovery rooms gives personnel the same protection against inhalation of anaesthetic gases as is afforded to personnel in operating theatres with scavenging equipment.
Hernodynamics during Superficial Thiopental Anesthesia in the Dog
Authors: Ahlgren I. , Aronsen K. F. , Björkman I. , Wetterlin S.
Published: January 2009

Radioactive microspheres, labeled with ytterbium (169Yb), strontium (85Sr) and cerium (141Ce) were used in an investigation of the cardiovascular response to superficial thiopental anesthesia. The course was followed for 90 min and measurements were carried out at 30, 60 and 90 min, respectively. Between 30 and 60 min of anesthesia there was a slight decrease in cardiac output and left ventricular work. The blood flow was reduced to the lungs, kidneys and the liver. Between 60 and 90 min there were, except for the coeliac artery and total liver, no further changes, which indicated a circulatory steady state.
The Hemodynamic Effect of Halothane in the Normovolemic Dog
Authors: Ahlgren I. , Aronsen K. F. , Björkman I. , Wetterlin S.
Published: January 2009

With the aid of radioactive microspheres (labeled with 169Yb, 85Sr and 141Ce, respectively), the effect of halothane anesthesia on circulation was studied for 30 min and (group A) for 120 min of halothane anesthesia in thiopental‐sedated dogs. Measurements were also carried out on recovery from halothane anesthesia. Besides such well‐known general circulatory changes as reduction in cardiac output, pulse rate, left ventricular work, arterial mean blood pressure and left atrial mean blood pressure, in both groups there was also a reduced coronary blood flow. The flow to the lungs, kidneys and the brain was well preserved, despite the reduction in both the cardiac output and arterial mean blood pressure. The flow to the liver, however, did not change during short halothane anesthesia; but during long anesthesia there was a marked reduction, due mainly to a decrease in the flow to the preportal area. On recovery from halothane anesthesia, the changes had mostly returned to the preanesthetic values.
The Effect of Halothane Anesthesia on Heart Function During Normovolemia and Hypovolemia in the Dog
Authors: Ahlgren F. Ingemar H.
Published: January 2009

The effects of halothane anesthesia on coronary circulation and cardiac work were studied in normovolemic and hypovolemic dogs, with the aid of the radioactive microsphere technique.

During normovolemia, halothane depressed the heart rate, cardiac output, arterial mean blood pressure and left ventricular work, with a simultaneous decrease in the coronary blood flow. During moderate hypovolemia, the arterial blood pressure was reduced as well as the coronary blood flow; whereas during hemorrhagic hypotension (severe hypovolemia), the arterial blood pressure was slightly increased and the coronary blood flow was unchanged with a reduced heart rate and increased stroke volume.
Venous Air Embolism through Infusion Sets Theoretical Considerations, Model Experiments and Prevention
Authors: Pedersen N. Thorsgaard , Hessov Ib
Published: January 2009

Some infusion sets are so designed that, even when infusing into peripheral veins, a negative pressure may occur in a large portion of the infusion tubing, with the result that air enters the system from a side drip which has run dry, or through leaks. In model experiments, it was found that, when infusing into a peripheral vein, volumes of air up to 13 ml per min can enter the system from an empty side drip. From an analysis of the pressure conditions in infusion sets before and during infusion, it is concluded that infusions sets should be so designed that clamps and connections for the attachment of a side drip are placed distally on the infusion tubing. Even then there is a risk of air embolism. The tubes for both the main and the side drip should therefore be so long that each of them can be fixed below the heart level of the patient, thus forming a waterlock and preventing the entry of air.
Cardiovascular Effects of Local Adrenaline Infiltration During Halothane Anaesthesia and Adrenergic Beta‐Receptor Blockade in Man
Authors: Pöntinen P. J.
Published: January 2009

Adrenergic beta‐receptor blocking agents, alprenolol, propranolol and practolol were given as a prophylactic measure to patients undergoing middle‐ear microsurgery where adrenaline was deliberately infiltrated during halothane‐N2O/O2anaesthesia.

These three beta blockers did not differ in their action on heart rate, arterial blood pressure, right ventricular pressure, CVP or peripheral pulse wave in equipotent doses, which were 0.04 mg/kg for alprenolol and propranolol and 0.4 mg/kg for practolol in this study. Atropine caused a highly significant increase in heart rate in the spontaneously ventilating group and maintained blood pressure at higher levels, although the latter difference was not significant.

Alprenolol and propranolol offered partial protection for over 40 min against adrenaline‐induced arrhythmias. Occasionally occurring tachyarrhythmias were easily terminated with a further dose of a beta blocker.

The effective half‐life of practolol was less than 15 min and doses up to 0.4 mg/kg were unable to prevent arrhythmias during adrenaline challenge.
Peroperative Haemorrhage and Epidural Anaesthesia in Major Abdominal Surgery A Retrospective Study
Authors: Jensen Mogens , Stokke Dag
Published: January 2009

The peroperative blood loss during resection of the colon, abdominal‐perineal excision of the rectum and cystectomy, according to the method of Bricker, was studied from anaesthetic reports. The period under study was 18 months.

A total of 97 patients were divided into two main groups according to the type of anaesthesia (general anaesthesia and general anaesthesia combined with epidural analgesia), as well as into sub‐groups according to the type of operation.

An evaluation was made of the blood loss, peroperative mean arterial blood pressure and the duration of the operation.

In contrast to reports published earlier on other types of operation, we have been unable to demonstrate a significant reduction in the blood loss of patients given general anaesthesia plus epidural analgesia, despite a lower mean arterial blood pressure during the operation.

We ignored any possible postoperative beneficial effect of epidural anaesthesia.
Renal Function During Neurolept Anaesthesia
Authors: Järnberg Per‐Olof , Santesson Joakim , Eklund Jan
Published: January 2009

Renal function and central haemodynamics were studied in eight patients, without known histories of renal or cardiovascular disease, during and immediately after upper abdominal surgery under neurolept anaesthesia. Inulin and PAH clearance, fractional sodium and fractional osmolal excretion decreased, while fractional free water reabsorption increased under anaesthesia. Cardiac output, mean systemic arterial pressure and systemic vascular resistance remained virtually unchanged both per‐ and postoperatively. Renal haemodynamics were promptly restored postoperatively, while fractional sodium and fractional osmolal excretion were unaltered and antidiuresis increased. It is concluded that neurolept anaesthesia, as far as renal function is concerned, is well suited for the anaesthetic management of the poor‐risk patient.
Acute Effects of Furosemide and Mannitol on Renal Function in the Early Postoperative Period
Authors: Järnberg Per‐Olof , Eklund Jan , Granberg Per‐Ola
Published: January 2009

The effects of furosemide and mannitol on renal function in the immediate postoperative period were studied in 16 patients, who had undergone upper abdominal surgery under neurolept anaesthesia. Renal function was studied preoperatively and during the first postoperative hour with a standard clearance technique. The patients were then randomly given furosemide, 1 mg/kg b.w., or mannitol, 0.5 g/kg b.w. Renal function was further investigated during the following 6 h in periods of varying duration. The injection of furosemide caused an initial increase of renal plasma flow (RPF), while glomerular filtration rate (GFR) decreased. Striking increases of urine flow, fractional sodium, fractional chloride and fractional osmolal excretion were found. These increases reached maximum levels during the second 20‐min clearance period after the injection. Fractional free water reabsorption decreased and during the first 20‐min clearance period it changed into free water clearance. These changes had reached or nearly reached the preoperative control levels after 6 h.

The infusion of mannitol caused an initial rise in RPF, while GFR remained stable. Increases were found in urine flow, fractional sodium, fractional chloride, fractional osmolal excretions and fractional free water reabsorption. The changes reached maximum levels during the first 20‐min control period and then gradually returned to the preoperative control levels.

Mannitol did not impair GFR and had a milder effect on renal function than furosemide. The losses of sodium and water were much smaller in the mannitol group than in the furosemide group. It is therefore concluded that mannitol should be used as the diuretic of choice in the treatment of postoperative oliguria in patients without known cardiovascular disease associated with increased preload and/or left ventricular insufficiency.
Reversal of Fentanyl‐Induced Narcotic Depression with Naloxone Following General Anaesthesia
Authors: Tigerstedt Irma
Published: January 2009

To study the need for and mode of naloxone reversal after liberal use of fentanyl during anaesthesia, a fixed‐dose schedule of fentanyl (mean 6.5 μg/kg/h) was applied intraoperatively to 60 patients, randomly divided into four treatment groups. After surgery and reversal of muscle relaxation, end‐tidal CO2 was allowed to rise to 8% by manually assisted ventilation. Thereafter, 0.04 mg increments of naloxone were given i.v. every 3 min until spontaneous respiration maintained ETco2 below 8% (group I) or below 6.5% (group II). After similar intravenous reversal to that in groups I or II, an additional intramuscular dose of naloxone, identical to that given i.v., was given to groups III and IV after awakening from nitrous oxide.

If ETco2 remained above 6.5%, mean spontaneous minute ventilation was lower than before anaesthesia and significantly (P<0.05) less than if ETco2 had decreased below that value. This difference had disappeared 45 min postnal‐oxone. Arterialized venous Pco2 showed normocapnia (6.0 kPa) in patients with ETco2 <6.5%, hut slight hypercapnia (6.6 kPa) in patients with ETco2>6.5% after intravenous naloxone. After 15 min, the patients with additional intramuscular naloxone had significantly (P<0.05) lower values of Pco2 than those with intravenous naloxone only.

Postoperatively, a positive correlation (R = 0.35) between the total dose of naloxone and pain intensity could be demonstrated (P<0.01). As acute postoperative pain could not be avoided after naloxone reversal to normoventilation, titration of naloxone after liberal use of analgesics is recommended with the help of capnography, until an acceptable ETco2 of about 7% is maintained.
A Circle System Without Carbon Dioxide Absorption
Authors: Ladegaard‐Pedersen H. J.
Published: January 2009

An anaesthetic circle system without a carbon dioxide absorber is described. The efficiency of the circle, i.e. the fraction of alveolar gas in the outflow from the circle, was measured in 15 patients during halothane anaesthesia or neurolept analgesia. The fraction ranged from 0.88 to 0.95 (mean 0.91), while the ratio between the alveolar ventilation and the fresh gas inflow ranged from 0.97 to 1.71. The efficiency was not correlated to this ratio. There was no need for hyperventilation if the fresh gas inflow was 10% higher than the alveolar ventilation required to maintain normal Paco2.

The circle was used in 50 patients manually ventilated by nurse anaesthetists. Mean fresh gas inflow was 60 ml/kg. Mean Paco2 was 5.47 kPa (41 mmHg). In a similar group of 50 other patients, in which the standard circle used in the department was employed, the mean Paco2 was 4.80 kPa (36 mmHg). The frequency of hypercapnia was equal in the two groups, but hypocapnia was not seen when the circle without absorber was used.
Hemodynamic Observation in Relation to Extensive Surgical Treatment of Patients with Increased Operative Risk
Authors: Sørensen M. Bredgaard , Bille‐Brahe N. E. , Engell H. C.
Published: January 2009

In 25 patients, considered high surgical risks according to clinical criteria, systemic and pulmonary hemodynamic parameters were monitored using a flow‐directed pulmonary arterial thermodilution catheter before, during and after major vascular surgery. During and after the operation, hemodynamic complications were observed in 13 patients. The following conditions were dealt with: hypovolemia, increased systemic vascular resistance, and left ventricular failure in hypervolemia and in normovolemia. Tachy‐arrhythmias seen in six of the patients were associated with left ventricular failure, hypovolemia or normal hemodynamics.

Operation for renovascular hypertension and thoracolaparotomy carried the highest risk. Two of the patients died from primarily surgical complications.
Individual Variation in Response to Thiopental
Authors: Christensen Jørgen H. , Andreasen Frederik
Published: January 2009

The anaesthetic records of 540 patients operated on during a 3‐week period were studied. The purpose was to elucidate the influence of age, sex, concentration of haemoglobin, creatinine concentration in serum, heart disease, and the premedication given on the size of the induction dose of thiopental. A statistically significant fall in dose with advancing age was seen after the age of 60 and the significance increased when a weight‐related dose was used for the calculations. A 6% difference, indicating a lower induction dose in women, was not statistically significant. When premedication with scopolamine and morphine had been used, significantly less thiopental was needed to induce anaesthesia than after atropine, diazepam and pethidine. When both sexes were considered, no correlation was found between haemoglobin concentration and induction dose of thiopental, but in two groups of women, weak negative correlations between these two variables were found. Thirty‐seven patients on long‐term treatment with digoxin and a diuretic required significantly less thiopental than 37 patients, otherwise comparable, not receiving this medication. About 60% of the dose used in 21 patients who were to have operations on their limbs was needed in 21 patients who were to be operated for valvular heart disease. Eleven patients with moderately elevated serum creatinine (average 2.1±1.0 mg/100 ml) required 11% (not statistically significant) less than 11 patients with normal serum creatinine (1.1±0.2 mg/100 ml). A considerable individual variation still exists for patients who are comparable with respect to all factors known to influence sensitivity to thiopental.
Haemodynamic Effects of Different Corticosteroids in Controlled Haemorrhagic Shock in the Dog
Authors: Hellman A. , Häggendal E. , Lindfors Maria , Lundberg D.
Published: January 2009

The haemodynamic effects of massive doses of hydrocortisone (80–320 mg.kg‐1), methylprednisolone (4–32 mg.kg‐l), betamethasone (1.6–12.8 mg.kg‐1) and aldosterone (0.1–0.8 mg.kg‐1) and the interaction with phenoxybenzamine and propranolol have been studied during controlled haemorrhagic shock in the anaesthetized dog. Hydrocortisone was the only steroid which showed any significant vasodilating ability when given alone. The alpha‐receptor blocking agent phenoxybenzamine distinctly decreased the total peripheral resistance. The effect of the phenoxybenzamine was increased in combination with hydrocortisone or methylprednisolone, especially if the steroid was given as the first drug. The vasodilation found was efficiently abolished by the beta‐receptor blocking agent propranolol. The ability of hydrocortisone or methylprednisolone to potentiate phenoxybenzamine was not shared by betamethasone or aldosterone. Thus, the haemodynamic effect of the steroid does not seem to be correlated to either a glucocorticoid nor a mineralocorticoid effect.

It is suggested that the steroid effect studied is related to the ability of hydrocortisone or methylprednisolone to block the extra neuronal amine uptake which decreases the rate of elimination of the sympathetic transmitter from the vicinity of the adrenergic receptor of the vascular smooth muscles.
Postanaesthetic Postural Stability Following Thiopental or Propanidid Anaesthesia
Authors: Eriksen Jørgen , Jansen Erik , Larsen Robert E. , Olesen Mogens B.
Published: January 2009

Using a quantitative Romberg‐test performed on a computerized force‐plate‐system, postural stability was tested in 39 patients before and 3 hours after general anaesthesia with either thiopental (20 patients) or propanidid (19 patients).

Sway‐tendencies in the sagittal and the transversal direction were recorded.

Comparing pre‐ and postoperative test results, patients anaesthetized with thiopental had a decreased postural stability 3 hours after anaesthesia, indicated by a significantly (P < 0.05) increased sway‐tendency of 22.6% in the sagittal direction. No change occurred in sway‐tendency in the transversal direction in this group.

In the propanidid group no significant differences were found between pre‐ and postoperative test results.
Effect of Pain on Human Psychomotor Performance
Authors: Korttila K. , Seppälä T.
Published: January 2009

The effect of pain on human psychomotor performance was measured in seven healthy volunteers after an intramuscular injection of vitamin B or saline using a controlled cross‐over method. Vitamin B, causing moderate to severe pain, or painless saline was injected into the buttock at a time when the subjects' performance was impaired after an intravenous injection of diazepam (0.3 mg/kg). The subjects' psychomotor performance was tested before and 2, 3, and 4 h after diazepam (before, 15 min, and 1 h 15 min after the vitamin Band saline injections). The effects of the vitamin B injection on the subjects' divided attention, reaction or co‐ordination skills or their ability to discriminate the fusion of flickering light did not differ from the corresponding effects of the saline injection. The results suggest that pain as such does not have any major influence on human psychomotor performance.
EEG‐Changes during General Anaesthesia with Enflurane (Efrane®) in Comparison with Ether
Authors: Persson A. , Peterson E. , Wåhlin Å.
Published: January 2009

The effects of enflurane (efrane®) and ether on the cerebral functions were studied by EEG on two similar groups of adult patients. For basic comparison a depth of anaesthesia was chosen which permitted abdominal surgery without the need to administer muscular relaxants. At this level of anaesthesia the typical EEG‐changes of paroxysmal type which have been described with enflurane were seen only occasionally. If, however, the depth of anaesthesia was further increased, such EEG‐changes indicating increased cerebral excitability were seen more often under enflurane and also appeared under ether anaesthesia. No seizure activity was recorded.
Effect of Respiratory Physiotherapy on Arterial Oxygen Tension
Authors: Hedstrand U. , Liw M. , Rooth G. , ÖGren C. H.
Published: January 2009

The effect of deep breathing on arterial oxygen tension was investigated in 45 postoperative patients. Arterial oxygen tension was estimated by the transcutan‐eous oxygen tension method, which allows continuous non‐invasive measurement of the arterial oxygen tension changes. Three deep breaths in 1 min, assisted by three respiratory therapy devices, were compared to a standard physiotherapy programme. A peak increase in arterial oxygen tension of 3–4.5 mmHg occurred after 1 min, and significantly increased values were seen for 2–4 min following deep breathing with the three respiratory devices. From the various physiotherapeutic procedures, verbally and manually assisted deep breathing gave a 7 mmHg Po2 peak and significantly increased values for 6 min.

The sigh mechanism is discussed in the light of the present knowledge of airway closure, which gives a satisfactory explanation of the short‐lasting increase in oxygen tension.
Effects of Acute Hypercapnia and Hypocapnia on Plasma and Red Cell Potassium, Blood Lactate and Base Excess in Man During Anesthesia
Authors: Finsterer U. , Lühr H.‐G. , Wirth A. E.
Published: January 2009

In order to test the relationship between changes in plasma potassium concentration and pH changes of respiratory origin, we produced hypercapnia (mean Paco2 71 mmHg = 9.5 kPa) in a group of 17 patients and hypocapnia (mean Paco2 21 mmHg = 2.8 kPa) in another 20 patients during neurolept analgesia and intra‐abdominal operations. A control group of 19 patients was studied under normo‐capnia but otherwise identical conditions. During hypercapnia, serum potasssium rose, ΔK/ΔpH amounting to—0.82, ‐1.05 and ‐1.34 after30, 60 and 90 min, respectively. During hypocapnia, serum potassium decreased, ΔK/ΔpH being a little more negative than during hypercapnia (mean values—1.62, —2.44 and —1.60). Red cell potassium concentration decreased in all three groups to a similar extent. Blood lactate levels during hypercapnia decreased to 75% of control and during hypocapnia rose to a maximum of 186% of control. In order to obtain reasonable values for base excess in primarily respiratory acid‐base disorders, it is necessary to use nomograms based on in vivo ECF‐COL‐titration curves. With this premise, hypercapnia or hypocapnia in our patients was not associated with significant changes in base excess.
Prolonged Apnoea after Suxamethonium: An Analysis of the First 225 Cases Reported to the Danish Cholinesterase Research Unit
Authors: Viby‐Mogensen J. , Hanel H. K.
Published: January 2009

During the last 4 years, 225 patients have been referred to the Danish Cholinesterase Research Unit following an episode of prolonged apnoea after suxaniethonium.

Fourteen patients (6.2%) were found to have a low serum cholinesterase activity due to an acquired deficiency (for instance, liver disease, chronic debilitating disease or carcinoma).

One hundred and forty‐eight patients (65.8%) had an inherited abnormal serum cholinesterase, and 105 of these patients (46.7%) were homozygous for the atypical enzyme (E1E1a). The mean period of apnoea in this latter group was 92 min (range: 25–240). Seventeen patients (7.6%) were heterozygous for the normal and the atypical enzyme (E1YE1a), with a mean apnoea period of 25 min (range: 7–60 min). Twelve patients were found to be heterozygous for the atypical and the silent gene (E1aE1s). The mean period of apnoea was 126 rnin (range: 45–210 min). Fourteen patients had other rare genotypes. The longest mean period of apnoea (170 min, range: 70–330) was found in patients homozygous for the silent gene (E1sE1s). The silent gene and the fluoride‐resistant gene were found in 8.9% and 2.7% of the patients, respectively.

In 63 patients (28.1%) both the type and quantity of serum cholinesterase were normal. In 34 of these patients (15.2%), the prolonged apnoea was due to other causes; for example, suxamethonium overdose, hyperventilation and central as well as peripheral respiratory depression. However, in the other 29 patients (12.9%), the reason for the prolonged apnoea could not be established. The possibility therefore exists that these cases represent unknown genotypes.
Preoperative Hemodynamic Evaluation of Patients Submitted for Major Surgery
Authors: Sørensen M. Bredgaard , Engell H. C.
Published: January 2009

Prior to major vascular surgery, hemodynamic studies were carried out in 63 patients by means of a flow‐directed pulmonary artery balloon catheter.

The results were correlated to electrocardiographic and roentgenologic findings, as well as to pertinent clinical information. Of 15 patients with either atrial fibrillation or both left ventricular hypertrophy and an increased cardiac volume, six had pulmonary pressures elevated above normal values; none of 14 patients with only one of the two signs (left ventricular hypertrophy or increased cardiac volume) had elevated pulmonary pressures. Also, the 34 patients with normal roentgenologic and electrocardiographic findings had normal hemodynamics, irrespective of a history of previous AMI, present angina or dyspnea on exertion.

It is concluded that hemodynamic studies by means of a balloon‐tipped catheter floating in the pulmonary artery are indicated before major surgery in patients with either atrial fibrillation or both electrocardiographic and roentgenologic signs of left ventricular hypertrophy. In such patients pulmonary pressures should be monitored during and after surgical operation.
The Elimination of Bupivacaine (Marcain®) after Short Intravenous Infusion in the Dog: with Special Reference to the Role Played by the Liver and Lungs
Authors: Irestedt L. , Andreen M. , Belfrage P. , Fagerström T.
Published: January 2009

The elimination of bupivacaine after a short intravenous infusion (1 mg. kg‐1 b.w. for 1 min) was studied in eight dogs. Special interest was focused on the roles played by the liver and lungs. By combining measurements of blood flows and blood concentrations of bupivacaine entering and leaving the liver, it was possible to quantify hepatic elimination of the drug. The concentration time‐curves from pulmonary arterial and aortic blood were similar as regards height and shape and thus did not verify the existence of a pulmonary uptake of bupivacaine of such significance that it dampened the aortic concentration time‐curve. The circulatory changes induced by the infusion were small. The plasma bupivacaine concentration often reached a peak well above 4 μg. ml‐1, but no symptoms of toxicity were registered. The elimination was very fast in comparison with that in man and is probably explained by both a higher hepatic extraction ratio and a greater hepatic blood flow kg‐1 b.w. in the dog. The results support the assumption of a first‐order hepatic hupivacaine elimination. The mean hepatic extraction ratio was constantly about 60% throughout the experiments, and the mean hepatic bupivacaine clearance about 25 ml. kg‐1 min‐1. Cumulative elimination time‐curves were calculated and it was demonstrated that the liver eliminated on average 80% of the given dose during the first hour after the infusion. Finally, it was shown that the mean cumulative elimination time‐curve was not easily linearized, which suggests that the liver eliminated more bupivacaine per time unit during the distribution period than would have been predicted from the usually assumed two or three‐compartment model. It is claimed that distribution volumes calculated by extrapolating the terminal decay slope of the semi‐logarithmic concentration time‐curve to time zero will partly consist of hepatic elimination.
Effect of Pancuronium on Plasma Free‐Norepinephrine and Epinephrine in Adult Cardiac Surgical Patients
Authors: Kumar S. M. , Kothary S. P. , Zsigmond E. K.
Published: January 2009

Since diazepam‐ketamine induction sequences in healthy humans cause no significant increase in plasma free‐norepinephrine and epinephrine, blood pressure and heart rate, we have frequently used a diazepam‐ketamine pancuronium sequence for induction of anesthesia in patients undergoing open‐heart surgery. In order to assess objectively the influence of pancuronium on sympathetic activity in cardiac patients, plasma free‐norepinephrine and free‐epinephrine were measured by Vend‐salu's method in the arterial blood of 12 patients who were to undergo valve replacement or coronary bypass. At the same time, arterial pressure measured by a strain‐gauge from the radial artery and heart rate measured by ECG were continuously recorded during induction with diazepam 0.3 mg/kg, followed 10 min later by ketamine 2.0 mg/kg. No significant changes occurred in these parameters before pancuronium administration. Plasma free‐norepinephrine and free‐epinephrine concentrations before and 5 min after pancuronium 0.1 mg/kg given over a 1‐min period were 0.42±0.05 (mean ± s.e.mean) and 0.45±0.05 ng/ml (P>0.1) and 0.01±0.003 and 0.02±0.009 ng/ml (P>0.1), respectively. A significant increase in heart rate followed pancuronium administration from 75.0±4.0 to 90.0±6.0 beatslmin (P<0.001). The corresponding systolic and diastolic direct arterial pressures were 148.0±9.4/74.0±6.0 and 153.0±8.3/81.0±5.2 mmHg (P>0.05). Although a statistically significant increase in heart rate was observed after pancuronium, no significant increase was found in plasma free‐norepinephrine, epinephrine or direct arterial pressure.
Effects of Antihypertensive Medication on the Cardiovascular Response to Ketamine in Rats
Authors: Kaukinen S.
Published: January 2009

The effects of hydralazine, clonidine, propranolol and methyldopa medications on the cardiovascular response to ketamine anaesthesia were studied in spontaneously hypertensive (SH) rats. Except in propranolol‐ and methyldopa‐treated animals, blood pressure was increased by ketamine in all groups. The heart rate was increased only in the normotensive control rats, whereas it was reduced in both the unmedicated and all of the medicated SH rats. Plasma renin activity under ketamine anaesthesia was markedly higher in normotensive control rats than in any of the SH groups. The pressor responses to dopamine and metaraminol were not altered by propranolol medication, but hydralazine suppressed these responses, while they were markedly intensified by clonidine and methyldopa treatment. Similarly, small additional doses of ketamine caused a pressor response only in clonidine‐ and methyldopa‐treated animals, whereas in the other groups the response was depressive. The tolerance to haemorrhagic shock during ketamine anaesthesia was notably improved by hydralazine and methyldopa medication, but impaired by propranolol treatment.

The results suggest that, with special reference to shock tolerance, hydralazine and methyldopa, and to a lesser extent also clonidine, have a favourable effect on the circulation under ketamine anaesthesia, whereas the action of beta‐blockade may be harmful.
Effects on Muscarinic Receptors of Various Agents in Reversal of Neuro‐muscular Blockade: A Study Evaluating Atropine, Glycopyrron, Neostigmine and Pyridostigmine
Authors: Eriksen S. , Hansen E. Kjær , Hasselstrøm L.
Published: January 2009

The effects were studied of various drug combinations, recommended for use in reversal of neuromuscular blockade, on heart rate and salivary secretions in 80 healthy patients anaesthetized with nitrous oxide‐oxygen‐halothane and relaxed with d‐tubocurarine. The drug combinations were mixtures of atropine 1 mg—neostigrnine 2.5 mg, atropine 1 mg—pyridostigmine 15 mg, glycopyrron 0.5 mg—neostigmine 2.5 mg, and glycopyrron 0.5 mg— pyridostigmine 15 mg, respectively.

It was found that administration of the atropine‐containing mixtures induced more pronounced initial increases and delayed decreases in heart rate than the mixtures containing glycopyrron. Pyridostigmine‐containing mixtures elicited a somewhat more pronounced initial increase in heart rate than neostigmine‐containing mixtures, but a less pronounced and delayed decrease in heart rate. Supraventricular arrhythmias occurred less frequently in the pyridostigmine groups than in the neostigmine groups. No such difference was found between the atropine and glycopyrron groups. Glycopyrron caused a more intense dryness of the mouth than atropine.

A differential attitude towards the use of drugs for reversal of neuromuscular blockade, based on the cardiovascular state of the particular patient, might be recommendable.
Non‐Polluting Dental Analgesia
Authors: Jörgensen S.
Published: January 2009

Threc anaestlletic circuits for Lise in nose‐piece application of inlialation analgesia are described. An ejector flowmeter is used for tlic scavenging of overspill gas.
Cerebrovascular Permeability to Protein in the Rat During Nitrous Oxide Anaesthesia at Various Blood Pressure Levels
Authors: Johansson B. B. , Linder L.‐E.
Published: January 2009

Rats anaesthetized with 70% nitrous oxide in oxygen have a high mean arterial pressure (MAP), usually in the range of 130–155 mmHg. It occasionally reaches higher levels, aiid when MAP exceeds 160 mmHg the cerebrovascular permcability may increase. In the prescnt study all rats with MAP>170 mmHg showed areas of protcin leakage in ihc brain. When dcaling with substancm that normally do not pass the blood‐brain barrier (BBB), this permeability increase may have important consequences. It is suggcsted that rats under nitrous oxide anaesthesia with MAP> 160 mmHg should not be included in studies in which an intact BBB is essential.
Influence of Lung Volume History on Closing Volume Measurement During Anaesthesia
Authors: Santesson J.
Published: January 2009

Airway closure measurements were made with the bolus technique on eight healthy subjects, who were in a supine position prior to and during anaesthesia. Measurements were made on an expiration following vital capacity (VC) and 30% VC. Closing volume (CV) was calculated prior to anaesthesia, and closing capacity (CC)—functional residual capacity (FRC) was estimated during anaesthesia. When measured from VC, CV was 703±20 ml (s.e. mean) and from 30% VC it was 440±51 ml (s.e. mean) (P< 0.005) prior to anaesthesia. When measured from VC, CC‐FRC was 370±34 ml (s.e. mean), and from 30% VCit was 343±37 (s.e. mean) (P>0.05) during anaesthesia. It is concluded that volume history has little effect on CC measurement during anaesthesia and artificial ventilation, but a major influence on CC measurement in the conscious patient. Hence, it is suggested that CC, within the tidal range, is increased during anaesthesia.
The Prognostic Value of EEG in Coma Survivors after Cardiac Arrest
Authors: Thomassen A. , Sørensen K. , Wernberg M.
Published: January 2009

EEG was recorded in 64 patients while they were in a state of moderate coma after cardiac arrest. The clinical course of the patients was followed, and the prognosis was compared with the EEG findings.

A total of 59 patients died within periods ranging from 1 to 287 days, 57 without having regained consciousness. Five patients survived, all with cerebral sequelae. The immediate causes of death were brain death in 18, pneumonia in 24, and cardiovascular complications in 17 cases. Autopsy was performed in 54 patients.

The EEGs were visually graded and classified into five groups, in order of increasing abnormalities (Hockaday et al. 1965). Of the records, 17% were unclassifiable. An extremely abnormal EEG (grade V) was indicative of death after a few days, while other grades of EEG changes did not give any prognostic indications. Good correlation was disclosed by multiple regression analysis between the length of the survival time and the EEG changes estimated on the basis of 12 variables.

A method is described by which it is possible to estimate the probable length of survival of a patient from his EEG records. There was a fair correlation between the estimated and observed survival times, except in the patients who died from cardiovascular complications after a few days. In these cases the prediction from the EEG was too optimistic.

It is concluded that EEG is a useful supplement to the clinical evaluation of patients in coma after cardiac arrest. The EEG must be assessed in a special way, as simple visual grading is of only limited prognostic value.
Maternal, Foetal and Neonatal Blood Creatine‐Phosphokinase‐Activities and Creatine‐Phosphokinase‐Isoenzymes after Labour with and without Epidural Analgesia and after Caesarean Section
Authors: Jouppila R. , Jouppila P. , Koivisto M. , Virkkunen L. , Wendt L. von , Pakarinen A.
Published: January 2009

Maternal, cord and neonatal blood creatine‐phosphokinase (CK) activities and CK‐isoenzymes were determined in connection with 24 labours after normal pregnancies. In eight cases there was a normal vaginal delivery; in another eight cases there was a normal vaginal delivery with segmental epidural analgesia; and In the remaining eight cases there was an elective caesarean section under general anaesthesia.

The lowest maternal blood CK‐activities were seen in connection with caesarean section. There was a statistically significant difference in the maternal CK levels after delivery between cases with caesarean section and normal labour (P<0.05) and between cases with caesarean section and labour with segmental epidural analgesia (P<0.001). Most of the maternal CK‐activity was of muscular type, and there were no statistically significant differences in isoenzyme fractions between the different groups.

The neonatal blood CK‐activities were at their peak at the age of 1 day in all groups. Between the groups there were no statistically significant differences in cord or neonatal blood CK‐activities at any time. Most of the cord and neonatal blood CK‐activity was also of muscular type, and there were no significant differences in the CK‐isoenzyme fractions between the groups.
The Effect of Acute Respiratory Acidosis on the Proportion: Total Splanchnic Perfusion/Cardiac Output, and the Alteration in this Proportion by Two Anaesthetics
Authors: Juhl B. , Einer‐Jensen N.
Published: January 2009

Eight dogs were anaesthetized and ventilated. Respiratory acidosis with variations in the pH (range: 7.49 to 7.05) were brought about by changes in the dead space of the apparatus. The pH‐related changes in cardiac output (Q), and total splanchnic perfusion (Qsp1) were studied during anaesthesia with mebumal natrium (NFN) N2O‐O2‐gallamoni jodidum (NFN) (“basic anaesthesia”), and after the addition of 1 % halothane (inspiratory). Similar relationships were demonstrated in the systemic circulation between pH changes and changes in the cardiac output, pulse pressure, and total peripheral resistance during both types of anaesthesia; whereas the pulse frequency and the mean aorti cpressure were not significantly correlated to changes in pH.

Qsp1 was different during the two types of anaesthesia. Under “basic anaesthesia,” the pH‐related changes in Q and Qsp1 were opposite and of varying magnitude. Their mutual relation: the fraction of cardiac output perfusing the splanchnic area, was Qsp1/Q= ‐2.28 + 0.34×pH (r = 0.69, N = 28, P<0.001). After the addition of halothane, no correlation could be demonstrated between Qsp1/Q and changes in pH. The changes in Q and Qsp1 were in the same direction and of the same relative magnitude, with an average of Qsp1/Q = 0.21. In agreement with this, no changes could be demonstrated in the total splanchnie resistance (Rsp1) during halothane anaesthesia in relation to the provoked pH changes, while Rsp1 under “basic anaesthesia” showed a slight rise with falling pH in the majority of dogs (six out of eight). The pressure in the portal vein (Pvp) appeared to rise with a falling pH. For both types of anaesthesia, the APvp (kPa) = ‐0.97 × δpH (r = 0.79, N = 34, P<0.001).
Effects of Positive End‐Expiratory Pressure on Renal Function
Authors: Järnberg P.‐O. , de Villota E. Dominguez , Eklund J. , Granberg P.‐O.
Published: January 2009

The effects were studied of positive end‐expiratory pressure (PEEP) on renal function in eight patients with acute respiratory failure, requiring mechanical ventilation. On application of PEEP+ 10 cmH2O, central venous pressure increased, systolic blood pressure decreased, urine flow and PAH‐clearance were reduced, while inulin clearance remained stable. There was a marked increase in fractional sodium reabsorption and a concurrent decrease in fractional osmolal excretion. Fractional free‐water clearance and the ratio Uosm/Posm did not change.
The Ejector Flowmeter: An Evaluation of its Accuracy
Authors: Waaben J. , Thomsen A.
Published: January 2009

The accuracy of five ejector flowmeters was assessed using three different gases and four flow‐rates. A soap‐bubble flowmeter was used for the calibration. Significant variations were found between individual flowmeters and between different gas mixtures. No variation was found between the four different flowrates, indicating that the calibration is linear. The mean calibration factor was 84.8% ±4.1 (100 % O2: 87.4±3.4, 50 % N2O/O2: 84.2±2.8, and 100 % N2O: 83.0±4.6).
The Influence of Thoracic Epidural Analgesia on the Circulation at Rest and During Physical Exercise in Man
Authors: Ottesen S.
Published: January 2009

The effects of thoracic epidural analgesia (TEA) on the circulation at rest, during, and after physical exercise were investigated in 10 volunteers. At rest, TEA did not affect oxygen consumption (Vo2) or cardiac output (Q), but heart rate (HR) was, increased by 7 beats/min, and stroke volume decreased correspondingly by 13 ml. Systolic arterial blood pressure was slightly reduced, but no other changes in systemic or pulmonary circulatory parameters were produced. TEA did not change VO2during exercise, a 2.1 l/min reduction of Q being accompanied by a 4.2% increase of oxygen utilization coefficient. HR showed a relative reduction of about 10%. At moderate work loads during TEA, systemic arterial blood pressures were significantly lower than during control exercise. The resulting rate pressure product (RPP) was markedly reduced, while total peripheral resistance (TPR) remained unchanged. During recovery after the termination of exercise during TEA, VO2, Q, HR, RPP and TPR fell more rapidly towards values obtained at rest. From a clinical point of view the results support the safeness of TEA and also support its use in surgical patients with heart disease.
Arterial Oxygenation During Artificial Ventilation: The Effect of Airway Closure and of its Prevention by Positive End‐Expiratory Pressure
Authors: McCarthy G.S. , Hedenstierna G.
Published: January 2009

Airway closure and arterial blood gases were measured in 11 healthy subjects, both before and during anaesthesia with artificial ventilation, prior to routine surgery. The functional residual capacity was then increased by positive end‐expiratory pressure (PEEP), so that ventilation took place at a lung volume where no airway closure was present, and the effect on arterial oxygenation was again investigated. A significant increase in alveolar‐arterial oxygen gradient occurred in the group of seven patients in whom airway closure within a tidal breath could be demonstrated during anaesthesia, but there was no significant change in the four patients in whom airway closure could not be demonstrated. There was no improvement in arterial oxygenation on increasing functional residual capacity (FRC) in either group. It may well be that this failure to improve oxygenation was due to a deleterious effect of PEEP on the circulation, even though the PEEP was the minimum required to abolish airway closure.