bluuebunny/crossref_metadata_2025 huggingface dataset:
Utilization of Pharrna‐Plast® Syringes for Gas Level Determination
Authors: E. Andreasen E. , Bøgh A.
Published: January 2009

A comparative study has been made of Pharma‐Plast® and Arterial‐Blood‐Sampler®‐B‐109 syringes. Thirtytwu syringes were studied in each group: their properties were compared with regard to blood sampling from intravascular catheters with the object of gas level determination. A comparison of the two groups showed no significant diffrrence. It is concluded that there are economic advantages in using the cheaper, simple Pharma‐Plast'K) syringes for gas level determinations, if the blood is withdrawn from an intra vascular catheter. They are particnlarly recommended for departments carrying out cardiac and vascular surgery, and for scientific prqjects.
Use‐Dependent Conduction Block Produced by Volatile General Anesthetic Agents
Authors: Strichartz G.
Published: January 2009

The ability of a tertiary amine local anesthetic, barbiturates, and several volatile general anesthetics to block conduction of the compound action potential was measured in the frog sciatic nerve. Action potentials from large myelinated fibers were monitored using a desheathed nerve preparation in a sucrose‐gap chamber. Supramaximal stimuli were applied over a range of stimulus frequencies from 0.1 Hz to 500 Hz. All three anesthetic agents produced a phasic, frequency‐dependent anesthetic block, which developed with repetitive stimulation and returned to a tonic level when the nerve remained at rest. Saxitoxin produced a frequencyindependent block. The frequency‐dependent conduction blocks produced by the tertiary amine anesthetic and by the barbiturates were potentiated by elevated Ca2+in the solution bathing the nerve, but Ca2+changes did not modify the block produced by any of the volatile anesthetics, so the latter agents probably art by a diffrent mechanism than local anesthetics or barbiturates.
Diazepam Under Hyperbaric Conditions in Rats
Authors: Gran L. , Coggin R. , Bennett P. B.
Published: January 2009

The effect of diazepam, expressed as loss of the righting reflex, in 60 adult rats compressed with oxygen /helium to 90 ATA was compared to 18 diazepam‐treated rats at 1 ATA. A marked pressure reversal of the loss of righting reflex was found. Convulsions provoked by high helium pressure were prevented by diazepam and the symptoms of High Pressure Nervous Syndrome (HPNS) were reduced.
Before Cannulation of the Radial Artery: Collateral Arterial Supply Evaluated by Strain‐Gauge Plethysmography
Authors: Husum B. , Palm T.
Published: January 2009

Systolic arterial pressure in the thumb was measured using strain‐gauge plethysmography before and after compression of the radial artery in 259 patients (aged 11–75 years), undergoing vascular or open‐heart surgery. In 38 hands (in 27 patients aged 37–75 years), manual compression of the radial artery reduced the arterial pressure in the thumb to less than 40 mmHg (5.3 kPa), and consequently the collateral ulnar arterial supply was judged to be inadequate. Because 27 out of 259 patients (10.4%) would be without adequate blood supply to one or both thumbs following occlusion of the radial arteries, cannulation of the radial artery should be performed only after ensuring the presence of an adequate collateral ulnar arterial supply.
Pretreatment with Non‐Depolarizing Muscle Relaxants: The Influence on Neuromuscular Transmission and Pulmonary Function
Authors: Howardy‐Hansen P. , Jørgensen B. Chræmmer , ØRding H. , Viby‐Mogensen J.
Published: January 2009

The influence of pretreatment with non‐depolarizing muscle relaxants on the neuromuscular transmission was evaluated in 40 healthy, awake, non‐premedicated volunteers using train‐of‐four (TOF) nerve stimulation and measurement of vital capacity (VC), inspiratory force (IF), peak expiratory flow (PEF), and forced expiratory volume in the first second (FEV1). The subjects were randomly allocated to one offour groups: group I received pancuronium 0.01 mg/kg; group II pancuronium 0.015 mg/kg; group III gallamine 0.3 mg/kg, and group IV gallamine 0.4 mg/kg intravenously. TOF ratio decreased significantly in groups II, III, and IV but not in group I following precurarization. Median (25 and 75 percentiles) TOF ratios after pretreatment were 94 (92–96), 89 (86–93), 92 (89–93), and 93 (87–96), respectively. Overall there were decreases in VC, IF, and PEF, but only the decrease in PEF was statistically significant in all four groups. FEVl was unchanged. The most pronounced decrease in VC, IF, and PEF (11,29, and 29 %, respectively) was seen in one subject in group II with a TOF‐ratio of 63 following precurarization. Four subjects (20%) in groups IIand IVexperienced difficulty in breathing. All subjects were, however, able to maintain head lift for more than 10 s, and none needed respiratory support. Seventy percent of all subjects had various minor complaints as, for instance, blurred vision and difficulty in swallowing. It is concluded that the higher doses of pancuronium (0.015 mg/kg) and gallamine (0.4 mg/kg) cannot be recommended for routine precurarization.
Incubation Conditions and Reversibility of a New Non‐Depolarizing Neurornuscular Blocking Agent, Org‐NC45
Authors: Krieg N. , Mazur L. , Booij L. H. D. J. , Crul J. F.
Published: January 2009

We describe the clinical use, for intubation purposes, of Org‐NC45, a new non‐depolarizing neuromuscular blocking agent. Administration of 50 and 72 μg/kg of this drug allowed good to excellent endotracheal intubation conditions within 3 and 2 min, respectively. In none of the cases was a signifcant change in blood pressure or heart rate seen after the injection of Org‐NC45. The resulting block was of short duration and, if necessary, was easily reversed with neostigmine or pyridostigmine.
Cardiovascular Effects of Sodium Nitroprusside in Cerebral Aneurysm Surgery
Authors: Lagerkranser M. , Gordon E. , Rudehill A.
Published: January 2009

Cardiovascular eflects of sodium nitroprusside (SNP) were studied in 17 patients undergoing cerebral aneurysm surgery under controlled hypotension. In 10 patients oxygen uptake was also calculated. Mean arterial bood pressure was decreased from 91 to 58 mmHgby SNP due to reductions in both total peripheral resistance (29%) and cardiac output (15%). Mean right atrial and pulmonary capillary wedge pressures were reduced during hypotension. Total oxygen uptake remained constant throughout the procedure. There was no signilicant change in arterial oxygen tension in the hypotensive period, but after discontinuation of SNP infusion it was significantly increased. The haemodynamic effects of SNP in patients with a recent subarachnoid haemorrhagc and its etrect on blood oxygenation are discussed. It is concluded that the fall in cardiac output is related to a reduction of central blood volume and might be more pronounced in these patients than in normal subjects.
The Closed Co‐Axial Analgesia System
Authors: Waaben J. , Jørcenses S. , Oxhøj H. , Arnsbo P.
Published: January 2009

A twin‐tube system for nitrous oxidc analgesia in dental surgeries is described. The system is a non‐polluting modification of the Mapleson A system, employing the principle of co‐axial tubing introduced by Bain & Sport. (1572). Active, continuous and calibrated gas removal takes place via the co‐axial tubing by means of an ejector flowmeter. Investigation of the dynamic pressure changes during simulated spontaneous breathing demonstrated that the maximum pressure excursions occurring at the nose‐piece are fully compatible with normal breathing. Gas contamination of the dental environment can be reduced by at least 90%. The system described is safe and easy to handle. It is made of light‐weight material and is adaptable to the equipment available. No rebreathing takes place when using a fresh gas inflow of 150 ml/kg body weight/min.
Effects of Adrenergic Neuron and Ganglion Blockers on Hemodynamics and Plasma Catecholamine Levels after Corticosteroids during Hemorrhagic Shock in the Dog
Authors: Haglund U. , Hellman A. , Haggendal E. , Haggendal J. , Lundberg D.
Published: January 2009

The involvement of adrenergic mechanisms in the ability of massive doses of methylprednisolone to potentiate the vasodilatory effects of phenoxybenzamine during controlled hemorrhagic shock was investigated. Dogs were subjected to ligation of the adrenals and, with the exception of the controls, were pretreated with either hexamethonium or bretylium. Despite careful surgery, the adrenal ligation,per se, failed to alter the concentration of plasma catecholamines. Hexamethonium and bretylium, on the other hand, both decreased the levels of plasma catecholamines: noradrenaline to a greater extent than adrenaline. Methylprednisolone was almost ineffective after ganglionic or adrenergic neuron blockade. Furthermore, the degree of vasodilation after methylprednisolone and phenoxybenzamine seemed to correlate better with plasma noradrenaline than with adrenaline. These findings indicate that the ability of methylprednisolone to induce vasodilation in the presence of adrenergic alpha‐receptor blockade in hypovolemic shock in the dog relies on an intact release of noradrenaline from postganglionic adrenergic nerve terminals.
Neurolept Anaesthesia for the Renal Transplant Operation
Authors: Lindahl‐Nilsson Ch. , Lundh R. , Groth C.‐G.
Published: January 2009

Between October 1973 and December 1976, neurolept anaesthesia was used in 176 consecutive renal transplantations carried out in 155 patients. For premedication, the combination either of droperidol, diazepam and atropine or of oxicon and scopolamine was used; the latter was found to be more effective. The induction agent was droperidol or thiomebumal sodium, the barbiturate being found to be preferable. For maintenance, nitrous oxide and fentanyl were employed. Pancuronium was given as a muscle relaxant. The fact that the patients belonged to a high‐risk category as regards anaesthesia was apparent from the frequent occurrence of abnormal features in the heart‐lung radiographs (47%) and ECG (53%). As could be expected in uraemic patients, anaemia and hypertension were fairly common. Induction was followed by a marked fall in blood pressure in 30% of the patients. During anaesthesia, there was a drop in blood pressure of more than 30% of the initial value in 35% of the patients, usually associated with a blood loss. In the majority of cases the course of the anaesthesia was uneventful. In four patients (2.3%), the onset of respiration was delayed and re‐intubation was resorted to. One patient developed arrhythmia requiring treatment. There was no evidence of nephrotoxicity. The per‐ and postoperative mortality was nil. The findings in this series indicate that neurolept anaesthesia is suitable for renal transplant operation.
The Influence of the Position on Some Haemodynamic and Ventilatory Parameters under General Anaesthesia
Authors: Videbæk F.
Published: January 2009

The effects of a change in posture from flat supine to supine with elevated and extended thorax have been investigated in 12 healthy patients under general anaesthesia prior to elective surgery on the stomach. The following parameters were measured: pulse rate, mean arterial blood pressure (MABP), central venous pressure (CVP), ventilation pressure, oesophageal pressure, and arterial oxygen and carbon dioxide tensions. Changes were measured as deviations from initial values before the change of position at 4 and 15 min after the change. One patient (8%) had a 31 % fall in MABP and a 87% fall in CVP, requiring treatment outside the standard procedure, but acceptable values were obtained by simple means. Eleven patients showed only minor changes: a mean initial rise in pulse rate of 10% and a fall in CVP of 25%, after which the pulse rate returned to the initial level and the CVP remained stable. MABP was unchanged, as were ventilation pressure, oesophageal pressure and gas tensions. On the basis of reports in the literature and findings in this study, it is concluded that otherwise healthy patients tolerate the posture well, the slight risk of haemodynamic complications being outweighed by the surgical advantages. This posture should be used with caution in patients who may be haemodynamically unable to compensate.
Double‐blind, Multiple‐dose Comparison of Buprenorphine and Morphine in Postoperative Pain
Authors: Tigerstedt I. , Tammisto T.
Published: January 2009

The analgesic profile and side‐effects of buprenorphine 0.3 mg and morphine 10 mg intramuscularly were compared postoperatively in a double‐blind, non‐crossover, multiple‐dose study. When the patient complained of moderate to severe postoperative pain after halothane‐relaxant anaesthesia for upper abdominal surgery, the first test dose of either drug was given. Subsequent similar doses of buprenorphine 0.3 mg or morphine 10 mg were given when required (maximum ten doses). The first dose of both drugs gave an equal decrease in pain intensity, suggesting a relative potency of 33:1 for buprenorphine/morphine. A mean of 0.51 mg buprenorphine or 17 mg morphine had to be administered for satisfactory initial analgesia. Thereafter, the next analgesic dose was required a mean of 10.3 h after buprenorphine compared to 5.9 h after morphine (P< 0.01). Significantly (P< 0.01) fewer analgesic doses (mean 5.6) were needed in the buprenorphine group within the first 48 h postoperatively as compared to the morphine group (mean 7.3). A more pronounced mean decrease in the respiratory rate was observed after buprenorphine, but the mean minimum respiratory rates did not differ significantly from each other. Other effects of the two drugs on vital signs were similar. The incidence of other side‐effects was fairly similar after both analgesics. The patients' subjective appraisal favoured buprenorphine.
Effect of Epidural Analgesia on Glucose Tolerance During Surgery
Authors: Jensen C. H. , Berthelsen P. , Kühl C. , Kehlet H.
Published: January 2009

Intravenous glucose tolerance tests were performed on 12 surgical patients the day before surgery and during surgery. Six patients were anaesthetized with enflurane and six were operated on during an epidural lumbar blockade (Th8‐S5). In the general anaesthesia group the plasma glucose concentration was significantly higher after the intraoperative glucose load than after the preoperative load. The pre‐ and intraoperative glucose tolerance tests were identical in the epidural group. Pre‐ and intraoperative glucose disappearance rates and plasma insulin responses were similar in the two groups, indicating that the observed differences in plasma glucose were caused by differences in hepatic glucose release, rather than differences in peripheral glucose utilization.
Experimental and Preliminary Clinical Studies of a Method of Reducing Anaesthetic Gas Contamination
Authors: Nilsson K. , Stenqvist O. , Lindberg B. , Kjklltoft B.
Published: January 2009

Long‐term exposure to low concentrations of anaesthetic gases is potentially hazardous. In spite of efforts to reduce the exposure of personnel by increased air conditioning, by scavenging of excess circuit gases and by improvements in anaesthetic equipment, high concentrations of gases have still been measured. Problems arise during mask induction, in paediatric anaesthesia, and in certain situations with unavoidable leaks, especially in small rooms but also in recovery rooms. Experimental and preliminary clinical studies have shown that nitrous oxide pollution can be considerably reduced by using a separate close scavenging system in the area where high gas concentrations occur. The geometrical and flow dimensions of a close scavenging device used in paediatric. anaesthesia are described.
Effects of Intercostal Nerve Blocks on Pulmonary Mechanics in Healthy Men
Authors: Jakobson S. , Fridriksson H. , Hedenstrom H. , Ivarsson I.
Published: January 2009

Bilateral block of the 5th through the 11th intercostal nerves was induced in 16 healthy men. In eight of the men, bupivacaine 0.25% was used and in the other eight, etidocaine 0.5%. Before and after induction of the block flow/volume curves, maximal airway pressures, and pulmonary compliance, were recorded, and helium spirometry and multiple and single breath nitrogen wash‐outs were performed. There were no differences between the results in the two groups, and the material was therefore pooled. Total lung capacity was decreased by 4%. There was no increase in residual volume, though the maximal expiratory airway pressure decreased by 7%. There was an 8% decrease in functional residual capacity. Pulmonary recoil appeared to be unchanged, as also did the effort‐independent peak expiratory flow rates. According to the pulmonary nitrogen clearance index, the overall pulmonary time constant did not alter, while the slope of the alveolar plateau in the single breath nitrogen wash‐out test increased by 9%. The significance of the latter finding is unclear, but it is concluded that the nerve block had no obvious effects on pulmonary mechanics, the changes observed rather being attributable to effects on the chest wall.
Do Moisture Exchangers Prevent Patient Contamination of Ventilators?
Authors: Stånge K. , Bygdeman S.
Published: January 2009

Fifteen tracheostomized and mechanically ventilated patients in an intensive care unit for surgical patients were studied. Two types of humidifiers were used: the Cascade humidifier and the Servo humidifier. Results from bacteriological cultures of the tracheal exudates, the expiratory and inspiratory ports of the ventilator, and various parts of the Servo humidifier are presented. There was a high incidence of colonization of the trachea of the patients. When the Cascade humidifier was used, a low rate of contamination in the expiratory and inspiratory ports of the ventilator was found, while no such contamination could be demonstrated with the Servo humidifier. There was a great difference in the colonization rate of the three different parts of the Servo humidifier. The part first exposed to the gas from the patient was frequently contaminated whereas the part towards the ventilator was not contaminated et all.
Transcutaneous Oxygen Measurement During Thoracic Anaesthesia
Authors: Gothgen I. , Degn H. , Jacobsen E. , Rasmussen J. P.
Published: January 2009

The value of transcutaneous oxygen tension (tcPO2) as an oxygen parameter during uncomplicated thoracic anaesthesia was examined in ten patients anaesthetized with oxygen‐nitrous oxide and enflurane or flunitrazepam/fentanyl. tcPO2 was measured with the Radiometer TCM‐1® monitor at 45d̀C. Measuring interference due to the anaesthetic agents was not observed. tcPO2 was found to be lower than the arterial oxygen tension (PaO2) at any inspiratory oxygen fraction (FIO2). When the peroperative readings were related to the preoperative values, no statistically significant difference was found between PaO2 and tcPO2 at FIO2 = 0.5, 0.4 and 0.3 (P > 0.3). Linear regression between PaO2 and tcPO2 shows disparity in pre‐ and peroperative regression. tcPO2 (preoperative) = ‐2.2+ 1.03 X PaO2 (r = 0.89), tcPO2 (peroperative) = +3.1 +0.56 X PaO2 (r = 0.87). This disparity indicates a decrease in the tcPO2/PaO2 ratio with increasing PaO2. It is concluded that tcPO2 cannot substitute for PaO2, but tcPO2 and PaO2 proved to be equally useful as oxygen parameters in the examined patients. Interpretation of tcPO2 during anaesthesia, however, necessitates a preoperative measurement as reference.
Subarachnoidal Block after a “Top‐up” Dose during Continuous Segmental Epidural Analgesia in Labour a Case Report
Authors: Kriz M. , Jouppila R.
Published: January 2009

We describe a case of spinal block which developed after a second “top‐up” of local anaesthetic during segmental epidural analgesia in labour. The incidence of similar cases is reviewed. The importance of aspiration and the injection of a “test” dose before every “top‐up” is stressed.
Nitrous‐oxide Analgesia During Ambulance Transportation. Airborne Levels of Nitrous Oxide
Authors: Ancker K. , Halldin M. , Göthe C J.
Published: January 2009

A model experiment was performed for studying nitrous‐oxide levels in the breathing zones of the different members of an ambulance team, viz. the anesthetist, the accompanying person in the ambulance coupe, and the ambulance driver. Without a functioning local exhaust coupled to the exhalation valve, the integrated average level of nitrous oxide in the breathing zone of the anesthetist was 650‐1,700 ppm, with top concentrations up to 7,500 ppm. Under the same conditions, the accompanying person in the ambulance coupe was exposed to average concentrations of 58–280 ppm, with top concentrations up to 660 ppm. The mean exposure of the driver was 9–45 ppm (max. 81 ppm). However, the exposure to nitrous oxide was considerably decreased in all parts of the ambulance by an effective local exhaust system. A prerequisite for nitrous‐oxide analgesia in ambulances is an effective local exhaust coupled to the exhalation valve or face mask. The ambulance coupé ought to be equipped with a motor‐driven exhaust fan in the roof, the ordinary inlet fan of the ambulance should be switched on at maximum speed, and any additional heater or fan in the ambulance coupe should be placed inside the coupé and not behind the driver's seat.
Simultaneous Computer‐Calculated Carbon Dioxide and Oxygen Direct Fick and Dye Dilution Measurements of Cardiac Output in Dogs
Authors: Noe F. E. , Whitty A. J. , Davies K. R.
Published: January 2009

Cardiac output was measured by both indocyanine green dye dilution and the direct Fick method using computer‐calculated values for oxygen consumption and carbon dioxide excretion in eight mechanically ventilated dogs anesthetized with pentobarbital, with either tubocurarine or succinylcholine intravenous drip for neuromuscular relaxation. Sequential measurements were made during the anesthesia and in response to pharmacologically induced increased cardiac output using doxapram hydrochloride (1.5 mg/kg) given intravenously.

The purpose of this project was to investigate the accuracy and reliability of the direct Fick measurements during anesthesia using computer‐calculated measurements of pulmonary gas exchange and, since these measurements have not been reported in detail previously, to establish tentative control values for future projects. The correlation of dye and direct Fick measurements of cardiac output during the first hour after induction of anesthesia was very good (r = 0.85 for all dye‐carbon dioxide Fick values; r = 0.83 for all dye‐oxygen 7 values).
Thermocamera, a Macroscopic Method for the Study of Pollution with Nitrous Oxide in Operating Theatres
Authors: Allander C. , Carlsson P. , Hallén B. , Ljungqvist B. , Norlander O.
Published: January 2009

Nitrous oxide (N2O) is used in high concentrations in inhalation anaesthesia and can serve as a tracer of other, more potent anaesthetic agents polluting the air of operating theatres. It has the quality of absorbing infra‐red light with a characteristic peak at 4.5 μm in the absorption spectrum. N2O in the operating‐room atmosphere will absorb infra‐red light emitted from a heat screen, and can therefore be registered by an infra‐red‐camera equipped with a filter eliminating waves outside the 4.5 μm waveband. The method was tested during paediatric inhalation anaesthesia. The infra‐red‐camera measurements are semi‐quantitative and sensitive to an extinction of about 1000 ppmcm, comparable to a N2O concentration of 100 ppm measured by an infra‐red N2O monitor. It was demonstrated that major pollution occurs during mask anaesthesia and after extubation. The polluting gas is insufficiently evacuated by the operating theatre ventilation. The method makes it possible to visualize the dispersion of spilled or leaking N2O, and is therefore of value when constructing and evaluating new scavenging equipment and in producing educational material.
Computer‐Calculated Pulmonary Carbon Dioxide and Oxygen Exchange in Human Subjects During General Anesthesia with Mechanical Ventilation
Authors: Noe F. E.
Published: January 2009

Computer calculation of minute‐by‐minute and breath‐by‐breath values for carbon dioxide excretion (v̇co2) and oxygen consumption (v̇o2) in human subjects during general anesthesia and mechanical ventilation were obtained with position changes and after drug administration to demonstrate a method for monitoring pulmonary gas exchange. A modified response to the intravenous injection of doxapram hydrochloride was observed in 12 patients with pancuronium bromide neuromuscular relaxation when they were compared with 12 patients who had been given tubocurarine. The data included representative values for v̇co2 and v̇o2 measured simultaneously in normal women after 1–2 h of balanced nitrous oxide‐oxygen‐fentanyl anesthesia with muscular relaxation and mechanical ventilation.
Early Response in Central Hemodynamics to High Doses of Sufentanil or Morphine in Dogs
Authors: Eriksen J. , Berthelsen P. , Ahn N. C. , Rasmussen J. P.
Published: January 2009

The hemodynamk effects of high doses of sufentanil, a newly synthetized highly potent analgesic, were investigated in dogs. This study compared the early (30 min) cardiovascular effects of sufentanil 0.01 mg‐kg‐1and morphine 4 mg‐kg‐1. Sufentanil caused a moderate and insignificant decrease in mean arterial pressure (MAP). A 30% decrease in cardiac index (CI) was almost outbalanced by an increased systemic vascular resistance (SVRI). The lowering of CI was due to a more than 50% decrease in heart rate (HR) which was partly compensated for by a greater stroke volume index (SVI). In the first 5 min after morphine injection, MAP fell significantly to about 50 mmHg (below 50% of the control value). CI was reduced to about 50% of the control value because of significant decreases in both SVI and HR. The calculated SVRI was unchanged alter morphine. Within 30 min some of the initially changed parameters had returned to control levels. Central venous pressure (CVP) and pulmonary capillary wedge pressure (PCWP) increased immediately after sufentanil, but decreased alter morphine. With time, both parameters returned towards control values. Peak left ventricular dP/dt decreased by about 25–50% after both analgesics. The rate‐pressure products (RPP) were significantly decreased to less than one half of the control values after both analgesics. Mixed venous oxygen tension (Pv̇o2), oxygen transport and oxygen consumption were significantly lowered in the sufentanil group, whereas immediate decreases after morphine were followed by gradual increases towards control values. We conclude that the use of high doses of sufentanil in dogs is safe. Apart from initial, transient changes, a stable cardiovascular stale characterizes the high‐dose sufentanil anesthesia, while morphine causes fluctuations in several hemodynamic parameters. Compared to morphine anesthesia, sufentanil anesthesia appears to be an attractive alternative which deserves further evaluation in humans.
Flow to Lung Compartments with Different Time Constants: Effect of Choice of Model
Authors: Epstein R. A. , Epstein M. A. F.
Published: January 2009

The thesis that an accelerating flow generator provides more even ventilation than a constant flow generator originated from studies using mechanical lung models. We simulated such studies by use of mathematical models. We found that the conclusions of these previous studies were dependent on the particular characteristics of their mechanical models. Studies employing more commonly used models indicate that constant flow generators, in fact, tend to provide more uniform ventilation, especially with long inspiratory times.
Portable Emergency Ventilators: Sensitivity to Environment
Authors: Dahlgren B.‐E. , Engdahl O. , Nilsson H.
Published: January 2009

The function in various types of climate of three ventilators which are commercially available in Sweden: Motivus®, Pneupac® 2 and Logic 07®, was tested as well as their sensitivity to vibration. The ventilators functioned in subzero temperatures only if the driving gas had a low humidity content. They also required an increased driving gas pressure. Only Logic 07 would function below — 20°C In a hot climate there were no functional disturbances. Motivus and Pneupac 2 had few resonance frequencies during the vibration tests. Logic 07 had a very marked resonance frequency at 60 Hz, as well as in other ranges, which disturbed the ventilatory function since the vibration affected the ventilatory frequency regulator. All three ventilators functioned without any complaints after being subjected to vibration tests for at least 15 min at the observed resonance frequencies, or to shock tests. The results suggest that a thorough scrutiny should be carried out of the function of compact ventilators in various environments.
A Preliminary Assessment of Atracurium, a New Competitive Neuromuscular Blocking Agent
Authors: Coker G. G. , Dewar G. H. , Hughes R. , Hunt T. M. , Payne J. P. , Stenlake J. B. , Waigh R. D.
Published: January 2009

Atracurium besylate, 2,2′‐(3,1 l‐dioxo‐4,10‐dioxatridecylene}‐bis‐[6,7‐dimethoxy‐l‐(3,4‐dimethoxybenzyl)‐2‐methyl 1,2,3,4‐tetrahydroisoquinolinium] dibenzenesulphonate is a potent non‐depolarising (competitive) neuromuscular blocking agent in the cat, monkey, dog and anaesthetised man. In man, it caused complete paralysis of the tetanic response of the adductor pollicis muscles at doses of 0.2 mg/kg. Blockade was of medium duration with rapid spontaneous recovery, and was readily reversed by neostigmine. The electrocardiogram, heart rate, arterial blood pressure and central venous pressure were virtually unchanged following doses of 0.2‐0.4 mg/kg. Intubation was readily accomplished in 1.5‐2 min after administration of 0.25‐0.3 mg/kg.
Lithium‐Droperidol Interaction and Risk of Diabetes Insipidus after Neurolept Anaesthesia
Authors: Serup J. , Brun C.
Published: January 2009

A 61‐year‐old woman presenting two episodes of nephrogenic diabetes insipidus following surgical operations performed under neurolept anaesthesia using droperidol (Dehydrobenzperidol®) and ientanyl (Haldid®) is reported. The patient was under long‐term lithium therapy for manic depression. She had minor signs of chronic lithium‐nephropathy. The episodes of diabetes insipidus were, essentially, lithium side‐effects, which became manifest through an interaction with droperidol used for neurolept anaesthesia. The lithium‐droperidol interaction acted at the organ level after a latent period of a few days. The interaction seems only to be manifest in rare cases, and well‐established use of lithium as well as droperidol should not be uncritically restricted.
Maternal and Foetal Drug Levels After Epicutaneous Application of a Local Anaesthetic Formulation Containing Ketocaine For Possible Use as Pain Relief in Labour
Authors: Jouppila R. , Teramo K. , Ulmsten U. , Purhonen M. , Hollmén A. , Berlin‐Wahlén A. , Gustafsson B.
Published: January 2009

A local anaesthetic formulation (A 2358) containing ketocaine, a local anaesthetic drug, was applied epicutaneously to the low back, Two compresses soaked with A 2358 were applied for 1 hour in 26 normal labours (or relieving referred pain from the low back. The maternal blood ketocaine levels remained low, compared to higher systemic levels reported in other studies. Maternal heart rate and blood pressure were stable during the application time. The mean umbilical vein/maternal vein and umbilical artery /maternal vein concentration ratios were 0.20±0.10 and 0.21 ±0.09. In addition, the foetal heart rate findings and the conditions of the neonates were satisfactory, thus suggesting the foetal safety of this analgesic method.
Central Haemodynamics and Oxygen Transport With and Without Continuous Positive Pressure Ventilation After Open‐heart Surgery
Authors: Vuori A.
Published: January 2009

Twelve patients, subjected 20 h earlier to coronary artery bypass surgery, were studied on discontinuation of the postoperative mechanical ventilation employing PEEP+5 cmH2O (CMV + PEEP). Compared to the values obtained during CMV + PEEP, cardiac index and mixed venous blood oxygen tension increased with the change to spontaneous ventilation at ambient pressure, employing a 28% O2 Ventimask® for the intubated patient. There was a slight decrease in both the arterial oxygen content and oxygen tension, but the increase in cardiac output compensated well for the lowering in the arterial oxygen content, and consequently the systemic oxygen transport was statistically unaltered. Oxygen consumption, pulmonary shunt fraction and arteriovenous oxygen content difference also remained unaltered. The observations suggest that after open‐heart surgery, CMV using a PEEP as low as+ 5 cmH2O may exert, in comparison to controlled oxygen therapy during spontaneous breathing, a significant lowering effect on the already compromised cardiac performance. This necessitates continuous weighing of the beneficial effects obtained by employing postoperative CMV + PEEP, against the adverse haemodynamic effects, although the alterations in cardiac output may partly ensue from the changes in metabolism, muscular effort and oxygen consumption during the two modes of ventilation, although there was no significant increase in oxygen consumption.
Clinical Study on an Endotracheal Tube with a High‐Residual Volume, Low‐Pressure Cuff
Authors: Saarnivaara L. , Grahne B.
Published: January 2009

The development of intracuff pressure in a Shiley tube with a high‐residual‐volume, low‐pressure cuff was studied in 61 patients during nitrous oxide‐oxygen anaesthesia and after replacement of nitrous oxide with nitrogen in the anaesthesia system. The mean minimal occluding pressure of the cuff filled with air was 18 cmH2O (1.8 kPa). In the 27 Group I patients, the intracuff pressure was always adjusted to its initial value after reaching the value of 25 cmH2O (2.5 kPa). In the 34 Group II patients, the intracuff pressure was allowed to increase freely. In Group I, the intracuff pressure reached the value of 25 cmH2O (2.5 kPa) in about 34 min. In Group II, the intracuff pressure increased linearly up to 120 min, reaching the value of 38 cmH2O (3.7 kPa). Thereafter, the increase in the intracuff pressure slowed to about 40 cmH2O (3.9 kPa) at 150 min. During 60 min after the replacement of nitrous oxide with nitrogen, the intracuff pressure in Group I decreased from 22 cmH2O (2.2 kPa) to 15 cmH2O (1.5 kPa) and in Group II from 36 cmH2O (3.5 kPa) to 24cmH2O(2.4kPa). During 240 min after extubation, the incidence of hoarseness ranged from 12 to 25% in Group I and from 19 to 28% in Group II. During 60 min after extubation, sore throat did not occur in Group I, whereas in Group II, its incidence was 13% (P < 0.05). No other side‐effects possibly associated with intubation were noticed. Eighty percent of the patients who developed side effects were women, whereas 60% of all patients were women. The present results suggest that even during a relatively short period of intubation of 120 to 140 min, the intracuff pressure should be controlled and kept below the value of 25 cmH2O (2.5 kPa).
Diazepam Adsorption to Infusion Sets and Plastic Syringes
Authors: Winsnes M. , Jeppsson R. , Sjöberg B.
Published: January 2009

The adsorption of diazepam to infusion sets and plastic syringes was studied. Infusion solutions consisting of diazepam injection (Valium®) in glucose 5.5%, diazepam emulsion (Diazemuls®) in glucose 5.5%, or diazepam emulsion in a lipid emulsion (Intralipid® 10%) were infused through two different infusion sets (Transcodan L‐74 and Cutter IL). It was found that, when an infusion solution with a low diazepam concentration (0.04 mg/ml) was infused slowly (4 ml/h), the diazepam adsorption was more than 80%. At a higher diazepam concentration (0.1 mg/ml) and increased infusion rate (20 ml/h) the adsorption decreased. Diazepam injection in glucose 5.5% was adsorbed to a higher degree (40–75%) than diazepam emulsion in glucose 5.5% (15–35%). When diazepam emulsion was diluted with the lipid emulsion, no diazepam adsorption to the infusion set occurred at this concentration and infusion rate. No significant difference between the two infusion sets could be found. The miscibility of diazepam emulsion with glucose 5.5%, glucose 10%, or sodium chloride 0.9% was examined. Diazepam emulsion proved to be miscible with glucose 5.5% and glucose 10%, but sodium chloride should not be used to dilute diazepam emulsion. The effect on the diazepam concentration of storing diazepam injection and diazepam emulsion in plastic syringes for up to 4h was also studied. It was found that the diazepam concentration remained unchanged during this time.
The Effect of Buprenorphine and Oxycodone on the Intracholedochal Passage Pressure
Authors: Tigerstedt I. , Turunen M. , Tammisto T. , Hästbacka J.
Published: January 2009

The effects of i.v, buprenorphine (0.3 mg) and oxycodone (10 mg) on intracholedochal passage pressure were studied in 20 patients who had undergone surgery of the common biliary tract, prior to the extraction of an indwelling T tube. Informed consent was obtained from all patients, each of whom was given buprenorphine or oxycodone in random order. The intracholedochal passage pressure was measured from the T tube perfused with continuous saline infusion (55 ml/h). Both analgesics significantly (P<0.01) increased the intracholedochal passage pressure after 5 min, with an equal peak increase of about 1.5 kPa at about 7 min. The pressure decline was rapid and similar in both groups: 20 min after administration of the test drug only about 40% of the maximum elevation caused by either drug remained. Thereafter, a slower fall towards the baseline was recorded after both drugs during the remaining 45 min of the study period. The results indicate that buprenorphine can be used with the same indications and precautions as other narcotics for postoperative pain relief in patients who have undergone surgery of the biliary tract.
Effects of Thiopentone on Cardiac Performance, Coronary Hemodynamics and Myocardial Oxygen Consumption in Chronic Ischemic Heart Disease
Authors: Reiz S. , Bålfors E. , Friedman A. , Häggmark S. , Peter T.
Published: January 2009

Thiopentone was administered as induction agent for general anesthesia to eight patients with stable ischemic heart disease; 6 mg/kg of the drug induced decrease in arterial blood pressure (— 27%), systematic vascular resistance (— 20 %), stroke volume index (—14%), mean pulmonary arteriolar occlusion pressure (— 15%) and left ventricular stroke work index (— 38%), while heart rate increased by 10% and cardiac output remained unchanged. Total body oxygen consumption decreased by 30%. Myocardial oxygen consumption decreased by 39% with unchanged or decreased myocardial oxygen extraction and myocardial lactate uptake decreased by 40%. Arterial and coronary sinus hypoxanthine levels were unchanged and no ST‐T‐segment changes or dysrhythmias were recorded. In the present experimental setting, the results indicate that thiopentone substantially decreased myocardial oxygen requirements. In spite of the marked reduction in coronary perfusion, myocardial oxygen demand was matched by supply, myocardial dysoxia was not induced and cardiodepression was clinically negligible. Rate pressure product was a poor indicator of changes in myocardial oxygen consumption after thiopentone administration.
Epidural Morphine for Postoperative Pain Relief
Authors: Reiz S. , Ahlin J. , Ahrenfeldt B. , Andersson M. , Andersson S.
Published: January 2009

Thirty‐three patients were randomly assigned to two groups to study the analgesic potency, duration of action and side effects of epidural and intramuscular morphine after hip surgery. Two milligrams of preservative‐free morphine chloride in 10 ml of normal saline in the epidural space was compared to 10 mg of intramuscularly administered morphine. There was a more rapid onset of action after intramuscular morphine. However, the quality of pain relief was substantially higher and the duration of action markedly longer after epidural morphine. The total dose required in the epidural group was 3.6 mg and in the intramuscular group 41 mg during the 15‐h observation period. The side effects of epidural morphine were few and mild, the most embarrassing being urinary retention (20 %). Nausea and/or vomiting was less common after epidural morphine (20% versus 55%). Pruritus or respiratory depression which have been reported previously were not encountered. However, it is recommended that preservative‐free solutions are used to avoid itching and that the patients are monitored, as respiratory depression may occur long after administration of epidural opiate.
Fatal Brain Lesion Following Spinal Anaesthesia: Report of a Case
Authors: Eerola M. , Kaukinen L. , Kaukinen S.
Published: January 2009

Leakage of cerebrospinal fluid following dural puncture and subsequent downward sagging of the brain have been suggested as a cause of the rare subdural haematomas occurring after spinal or attempted epidural anaesthesia which have been reported in the literature. We report a case where this mechanism probably produced a fatal brain lesion, due to the herniation of the uncus against the tentorium cerebelli 15 days after spinal anaesthesia. The patients complained of severe headache and nausea after the procedure. The reported case shows that postdural‐puncture headache may be a sign of more serious sequelae and should be treated by the means available.
Influence of Plasma Oncotic Pressure on Lung Water Accumulation and Gas Exchange After Experimental Lung Injury in the Pig
Authors: Zetthrström H. , Jakobson S. , Janerås L.
Published: January 2009

In 18 anaesthetized and artificially ventilated pigs, oleic acid was infused intravenously in order to induce a lung injury characterized by increased lung water content, decreased compliance and a ventilation/perfusion disturbance. After a stabilizing period, half of the animals (group P) underwent repeated plasmapheresis, which halved their plasma oncotic pressure (POP). The rest of the animals were bled and re‐transfused with the shed blood, thus serving as a control group. In both groups, care was taken to keep the mean left atrial pressure as constant as possible. During plasmapheresis and “shamapheresis”, there was no significant increase in venous admixture (Fio2 0.21 and 0.6) in either of the groups. At the end of the study, end‐inspiratory pressure, dead space/tidal volume ratio and wet/dry lung weight ratio (WW/DW) were significantly higher in group P. Venous admixture and WW/DW correlated significantly with pulmonary arterial pressure and calculated pulmonary capillary pressure, but not with POP or POP minus pulmonary arterial occlusion pressure. It is concluded that reduction of plasma oncotic pressure may increase the lung water content in previously injured lungs, but this extra water accumulation does not necessarily impair oxygenation in the lungs.
Albumin Treatment Following Major Surgery
Authors: Zetterstrom H.
Published: January 2009

The effects of i. v. infusion of 5% albumin and balanced salt solutions were investigated in a prospective study on 18 patients subjected to reconstruction of the abdominal aorta. The same schedules for blood replacement and intraoperative fluid therapy were followed for all patients. Postoperatively, the amounts of fluid administered were adjusted with the aim of keeping the mean pulmonary arterial occlusion pressure (MPAOP) close to the preoperative level. Immediately after operation, there was a decrease in cardiac filling pressures, indicating a blood volume deficit, in both groups. Less fluid was needed for adequate haemodynamic restitution in the albumin group. Postoperatively, the mean plasma oncotic pressure (POP) in the albumin‐treated patients remained steady at 2.4‐2.5 kPa (86–88% of preoperative value). In the control group, POP fell to a mean minimum of 1.8 kPa (64% of preoperative value) 8 h after operation. The difference between POP and MPAOP decreased significantly in both groups, but the difference between the groups was not significant at any time. There was no significant correlation between venous admixture, on the one hand, and POP, MPAOP, POP‐MPAOP difference, total sodium intake or net supply of non‐colloid fluids, on the other. No clinically important differences in haemodynamic or lung function variables were found between the groups.
Preanaesthetic Medication with Rectal Diazepam in Children
Authors: Ahn N. Chr , Andersen G. W. , Thomsen A. , Valentin N.
Published: January 2009

With the purpose of avoiding injections to children, the quality of rectal premedication with a solution of diazepam (Apozepamr̀) was investigated in a double‐blind study. Compared with a lytic cocktail (containing pethidine, promethazine and chlorpromazine), adequate preanaesthetic sedation was obtained with rectally administered diazepam in a dose of 0.75 mg kg‐1. However, following rectal diazepam, the majority of the children were very restless during recovery, but the combination of diazepam premedication and a small dose of lytic cocktail given i. m. during anaesthesia secured a smooth recovery in practically all children. The proportion of cases classified as “unsatisfactory” was higher in children below the age of 5 years than in the older children.
Comparison of Laryngotracheal and Ultrasonic Nebulizer Administration of Lidocaine in Local Anaesthesia for Bronchoscopy
Authors: Korttila K. , Tarkkanen J. , Tarkkanen L.
Published: January 2009

Inhalation of nebulized minute lidocaine droplets has been suggested to be a very safe and pleasant method to produce topical anaesthesia for bronchoscopy. We produced topical anaesthesia of the respiratory tract either by laryngotracheal spraying (LS) of lidocaine (439±85 mg) or ultrasonic nebulizer administration (UNA) of lidocaine (462±81 mg) in 40 patients undergoing bronchoscopy. All patients also received an average of 15 mg of diazepam intravenously. Both modes of lidocaine administration produced adequate anaesthesia and were safe, but when rated on the visual analogue scale, both the efficacy of local anaesthesia and the cooperation of patients during bronchoscopy were better (P<0.05) after LS than those after UNA. The peak plasma concentrations of lidocaine (means ±s.d.) were lower and occurred earlier after UNA (0.53 ±0.34 μg/ml at 5–15 min after administration) than those after LS (0.89±0.63 μg/ml at 15–25 min after spraying). The highest individual values measured (2.54 μg/ml after LS and 1.17 μg/ml after UNA) were much less than those measured 1 and 15 min after i.v. administration of 2 mg/kg of lidocaine in another ten patients and far below the reported toxic lidocaine plasma concentrations. It is concluded that bronchoscopy can be conducted under local anaesthesia as successfully and safely using inhalation of lidocaine droplets from an ultrasonic nebulizer as when using laryngotracheal spraying of lidocaine.
Pentoxifylline Does Not Protect Mice Against Hypoxia
Authors: Steen P. A. , Michenfelder J. D.
Published: January 2009

Pentoxifylline 12.5–200 mg/kg failed to increase the survival time of mice exposed to oxygen, 5%. Other measures have previously been shown to increase survival time in this model, probably by improving the ratio of energy supply to demand. This has been accomplished by either increasing cerebral blood flow or decreasing cerebral energy consumption. Contrary to previous reports, it thus seems unlikely that pentoxifylline favorably affects these factors, at least in this model.