bluuebunny/crossref_metadata_2025 huggingface dataset:
Epidural sufentanil for intra– and postoperative analgesia in thoracic surgery: a comparative study with intravenous sufentanil
Authors: Rosseel P. M. J. , Van Den Broek W. G. M. , Boer E. C. , Prakash O.
Published: January 2009

A eomparative study was undertaken to evaluate the effectiveness of epidural sufentanil in providing intraand postoperative analgesia during thoracic surgery. Sufentanil was chosen on the basis of its high lipid solubility and its potent opiate receptor binding. Epidural sufentanil was compared with intravenous sufentanil as the major intraoperative analgetic agent in an anesthesia regimen with midazolam and nitrous oxide. Epidural sufentanil significantly decreased the need for supplementary intravenous analgesia. In the epidural sufentanil group the immediate postoperative analgesia was found to be better, with a longer duration of action, compared with the intravenous sufentanil group. Postoperatively epidural sufentanil was compared with epidural morphine. Sufentanil provided good analgesia with a very fast onset and a mean duration of almost 7 h. Severe respiratory depression was observed in one patient within 1 h of extubation, probably due to the combined effects of the narcotic administration and residual midazolam. It is concluded that 50 pg of sufentanil administered in the thoracic epidural space provides valuable intraoperative analgesia which can easily be extended into the postoperative period, although all necessary precautions for epidural opiate administration should be taken.
Detection of embolized material in the right atrium during cementation in hip arthroplasty
Authors: Svartling N.
Published: January 2009

Preeordial Doppler ultrasound, hemodynamic changes and end–tidal carbon dioxide (ETco2) were monitored in 36 patients undergoing hip surgery in general anesthesia. Changes in Doppler ultrasound indicative of embolization were recognized in 22 out of 36 patients during femoral cementation. The character of the ultrasound was suggestive of air emboli, though simultaneous embolization of bone marrow could not be excluded. Embolization was associated with a fall in arterial oxygen tension (Pao2). Both embolization and reduction of Pao2 were influenced by the cementation technique. Digital anterograde insertion and insertion by syringe of acrylic bone cement into the femoral cavity caused ultrasound changes in 92% and 75% respectively, whereas retrograde insertion of low viscosity bone cement was accompanied by ultrasound activity in only one patient (9%). The blood levels of monomeric methylmethacrylate (MMA) released from the low viscosity bone cement ranged from 0.04 to 7.01 μg/ml‐1. Doppler ultrasound monitoring gave valuable help during cementation, as the ultrasound change immediately signalled a warning of embolism and an imminent decrease in Pao2.
Partial reversal of the cerebral effects of isoflurane in the dog by the benzodiazepine antagonist flumazenil
Authors: Roald O. K. , Forsman M. , Steen P. A.
Published: January 2009

Six dogs initially anaesthetized with isoflurane–N2O–O2for surgery with cannulation of the sinus sagittalis for direct measurement of cerebral blood flow (CBF) and maintained with 1% isoflurane–N2–O2anaesthesia, were given two 2–mg doses of the benzodiazepine antagonist flumazenil with an interval of 10 min. This was accompanied by a significant increase in the cerebral metabolic rate for oxygen (CMRo2) 10 min after the first 2–mg dose, and 5, 10 and 15 min after the second 2–mg dose, the increase varying in mean value from 9% to 14%. EEG was recorded in five of the six dogs and administration of flumazenil converted the EEG from a sleep pattern to an awake pattern in two of them. There were no significant changes in the CBF or mean arterial blood pressure (MABP) values. In the brain biopsies taken at the end of the study there were no significant changes in the adenylate energy charge (EC) and the lactate/pyruvate ratio (L/P) when compared to five other dogs not given flumazenil. It is concluded that flumazenil in this study demonstrated a partial antagonism of the cerebral effects of isoflurane.
Increased lethality and delay in the recovery of hemopoietic stem cells after irradiation in mice exposed to nitrous oxide
Authors: Konno M. , Kirikae T. , Suzuki K. S. , Yoshida M. , Mori K. J. , Wakusawa R.
Published: January 2009

Effects of N2O–exposure on the survival rate and growth kinetics of hemopoietic stem cells after irradiation were investigated. LD 50, 30 days after irradiation, was 300 rad for N2O exposed mice and over 550 rad for control mice. Recovery of the pluripotent hemopoietic stem cells (CFU–S) and granulocyte–macrophage progenitor cells (GM–CFC) was significantly delayed in the spleen of N2O–exposed mice after 150 rad irradiation, compared to that of control mice. However, in bone marrow, there was a significant but slight difference in the recovery of GM–CFC and no significant difference in the recovery of CFU–S between the two groups. These results suggest that N2O augments the damage of splenic hemopoiesis in irradiated mice, and this may be responsible for the increased hemopoietic death.
Hydroxyethyl starch 120, dextran 70 and acetated Ringer's solution: hemodilution, albumin, colloid osmotic pressure and fluid balance following replacement of blood loss in pigs
Authors: Linko K. , Mäkeläinen A.
Published: January 2009

Twenty healthy pigs weighing 12–17 kg were anesthetized and the small intestines were exteriorized into saline–moistened gauze. During a 2–h period 4% of the animals' body weight was bled through an arterial cannula in six increments and replaced immediately by the fluid tested: hydroxyethyl starch 120 (HFS, Plasmafusim®, Orion Corp., Mw 120 000), dextran 70 (DEX) and Ringer's acetate (RA). The amount of fluid infused for replacement of blood loss was equal to the amount of blood withdrawn in the colloid groups but fourfold in the RA group. Five non–bled pigs served as controls. After the hemodilution the laparotomy was closed and the animals received only 5% dextrose (2 ml/kg/min) during a 5–h follow–up period. The synthetic colloids caused a more effective dilution of hemoglobin and albumin than did RA. The colloid osmotic pressure (COP) was well maintained by the plasma substitutes but decreased in the RA group to 64% of the initial values. A stable urinary output and no edema formation was found in the HKS and DFX groups. The RA animals were unable to excrete the excess crystalloid, which resulted in a strikingly positive fluid balance persisting throughout the study. Thus, the synthetic colloids were superior to RA in expansion of the plasma volume, maintenance of the COP and prevention of fluid accumulation. The effect of the iwo colloids was similar except that COP was slightly better maintained during the follow–up period in animals which received HES 120.
The acceleration transducer – an assessment of its precision in comparison with a force displacement transducer
Authors: May O. , Nielsen H. Kirkegaard , Werner M. U.
Published: January 2009

A new and simple acceleration transducer (ACT)–based system of neuromuscular monitoring has recently been introduced. The precision of this transducer has been evaluated as compared to a conventional force displacement transducer (FDT) in the present study. Ten progressions of spontaneous recovery from atracurium–induced block with simultaneous measurements using the ACT on one hand and the FDT on the other were studied. Five individuals undergoing elective surgery in modified neurolept anaesthesia and one ICU–patient requiring prolonged neuromuscular blockade, sedated with pentobarbital, were included. Measurements were carried out on the latter patient on 5 consecutive days. Train–of–four (TOF) stimulation was used, readings were given in twitch heights (TH) (Tl/control value), and when four responses were obtained in TOF–ratios (T4/T1). Linearity was achieved after logit–transformation and the values regressed on time for each progression of recovery. Analysis of variance was applied to the regressions for the TH and TOF–ratio readings of each transducer. No significant differences were found, either between variation due to differences between slopes or variation due to technical error between the two transducers. The study indicates that the ACT is equal to the FDT with regard to precision in clinical recordings on atracuriumrelaxed individuals.
Optimal time interval between pretreatment with alcuronium and suxamethonium during anaesthetic induction
Authors: Lindgren L. , Klemola U. M. , Saarnivaara L.
Published: January 2009

Alcuronium 0.03 mg/kg was studied in a double–blind randomized fashion as a pretreatment before suxamethonium using different time intervals between the administration of the drugs in 78 patients (ASA I–II) undergoing otolaryngological surgery. Alcuronium was given 1, 2 or 3 min before suxamethonium 1.3 mg/ kg. The control group received saline as a pretreatment and suxamethonium 1 mg/kg. Anaesthesia was induced with thiopental 5.5 mg/kg over 60 s. Muscle fasciculations, intubating conditions, cardiovascular responses to endotracheal intubation and duration of neuromuscular block were assessed. Muscle lascicul–ations were statistically and similarly inhibited (P < 0.01) at all time intervals between alcuronium ami suxamethonium. Intubating conditions were worse (P < 0.05) in the 3–min group than in the other groups. Cardiovascular responses to endotracheal intubation were similar in all groups. The neuromuscular block after suxamethonium was significantly shorter (P < 0.05) in the 2– and 3–min groups than in (he other groups. In conclusion, from the clinical point of view the 1–min time interval between alcuronium and suxamethonium is optimal since muscle fasciculations are inhibited and intubating conditions are satisfactory.
Impact of surgical stress on the haemodynamic profile of isoflurane–induced hypotension
Authors: Bernard J. M. , Pinaud M. , Macquin–Mavier I. , Remi J. P. , Souron R. , Bainvel J. V.
Published: January 2009

It has been suggested that stimulation of adrenoreceptors could be responsible for some of the haemodynamic effects of isoflurane. But there are no solid data demonstrating the role of sympathoadrenal stimulation induced by pain during isoflurane administration. The impact of surgical stress on the haemodynamic profile of isoflurane–induced hypotension has been investigated in 28 patients (47 76 years), scheduled for total hip arthroplasty. After premedication with morphine hydrochloride (0.1 mg/kg), patients were randomly assigned to receive either no fentanyl (control group) or fentanyl (5 μg/kg before tracheal into ion, 5 μg /kg before skin incision, and 2 μg/kg each 15 min during the 1st hour). Isoflurane … given to maintain mean arterial blood pressure in the range 6.7–8 kPa in both groups. Haemodynamic data and blood samples for determination of plasma renin activity (PRA) and epinephrine (E) and norepinephrine (NE) levels were collected before and during hypotension. The fentanyl group and the control group differed significantly during hypotension: heart rate, cardiac index, oxygen consumption and K, NE and PRA were lower (P < 0.01) in the fentanyl group than in control group. Fentanyl lowered the required concentration of isoflurane to achieve the same degree of hypotension (end–tidal concentration: 0.8 ± 0.2% in the fentanyl group and 1.4 ± 0.15% in the control group; P < 0.001). Our results demonstrate that the cardiovascular effects of higher isoflurane concentrations in the absence of narcotic analgesia are counterbalanced by adrenergic stress stimulation of released epinephrine and norepinephrine. Among the likely reasons for catecholamine release during isoflurane administration, inadequate analgesia may be considered.
Clinical experience of long–term treatment with epidural and intrathecal opioids – a nationwide survey
Authors: Arnér S. , Rawal N. , Gustafsson L. L.
Published: January 2009

Long–term use of spinal opioids to treat chronic severe pain is widely established. However, the indications, shortcomings and complications of the method have not been completely described. Experience with spinal opioids was analysed for the period 1979–1984 in a nationwide Swedish survey. Out of 93 anaesthesia departments, 69 used the method. Approximately 750 patients were treated with epidural morphine for an average duration of 124 days (3–450). Eighteen patients were treated with intrathecal morphine for an average period for 47 days (3–90). The intrathecal approach was used in all clinics because of failure of the epidural route. In only one department was the intrathecal approach used as the primary route of therapy, depending on the mechanism of pain. The highest daily morphine dose was 480 mg and 50 mg for epidural and intrathecal routes, respectively. The patients given the highest dosages were not necessarily those subjected to the longest treatment. The need for increased dosage seems to be related not only to changes in receptor sensitivity but also to changes in pain mechanisms. No case of threatening ventilatory depression was reported. Thirty–two departments had treated a few patients with chronic non–cancer pain conditions. Initial results were considered “excellent” in H departments, but at follow–up results were excellent in only one department. In addition to dislocation, occlusion of the catheters or leakage, injection pain was an obstacle to successful treatment. Pruritus, urinary retention, and local infections were not reported as significant problems, but one case of meningitis was reported.
Half–life of plasma cholinesterase
Authors: ØStergaard D. , Viby–Mogensen J. , Hanel H. K. , Skovgaard L. T.
Published: January 2009

The half–life of plasma cholinesterase (acylcholine acylhydrolase EC 3.1.1.8) was determined in three patients homozygous for the atypical gene for plasma cholinesterase by measuring the rate of disappearance of enzyme activity following intravenous injection of concentrated human cholinesterase. Half–life values of 10.9, 11.1, and 11.3 days were estimated. The distribution volume was estimated to be 18.0, 18.2, and 13.8% of body weight, respectively.
Effects of ephedrine on renal function in patients after major vascular surgery
Authors: Westman L. , Hamberger B. , Järnberg P. O.
Published: January 2009

The haemodynamic and renal effects of ephedrine were studied in 11 mechanically ventilated patients on the first day after major vascular surgery. Ephedrine, a sympathomimetic agent with alpha–1, beta–1, and beta–2 agonistic activity, was infused into 11 patients to achieve a 20% rise in systolic blood pressure. The doses used were 2–6 μg/kg/min, and in six of these 11 patients the dose was then doubled, 4–12 μg/kg/min for another renal function test. Blood pressure, heart rate, and cardiac output increased at both dose–ranges. Systolic pulmonary arterial pressure increased by 10% at the first dose–range. Systemic vascular resistance was unchanged and plasma catecholamine levels were unaltered in the present study. Plasma renin activity diminished by 18% and 6%, respectively. Clearance of para–aminohippuric acid increased by 20% and 6%, at the two dose–ranges, while clearance of inulin and urine flow rate increased by 24% and 29%, respectively, at the first dose–range, without further increase during the second dose–range. Fractional chloride excretion, and fractional osmolar clearance were unaltered. Fractional Na+ clearance rose by 30% and 36%, respectively. Fractional free water clearance diminished by 8% at the second dose–range. When comparing the two dose–ranges, HR, systolic and mean BP rose by 8%, 13% and 11%, respectively. Fractional K+ excretion diminished by 30%. We conclude that ephedrine given as a continuous infusion seems to have beneficial effects on renal function in patients after elective major vascular surgery.
Acute carbon monoxide poisoning
Authors: Krantz T. , Thisted B. , Strom J. , Sørensen M. Bredgaard
Published: January 2009

The course and outcome in terms of cerebral morbidity and hospital mortality in 79 severely carbon monoxide poisoned patients admitted to the intensive care unit during a period of 15 years is presented. Treatment consisted of administration of pure oxygen. Ninety–four per cent of the patients were artificially hyperventilated, and the majority of the patients were also treated with moderate hypothermia, steroid hormones and diuretics. Hospital mortality was 30%, and 14% of the patients were discharged after long–term hospital treatment with signs of brain damage. Due to the unpredictable cerebral course after the acute incident long–term follow–up is recommended.
Respiratory failure in mice caused by a hybridoma making antibodies to the 15 kDa surfactant apoprotein
Authors: Suzuki Y. , Robertson B. , Fujita Y. , Grossmann G.
Published: January 2009

Hybridoma cells were obtained by fusing spleen cells from mice, immunized against the 15 kDa porcine surfactant apoprotein, with a myeloma cell line. Adult mice were inoculated intraperitoneally with this hybridoma; mice that were not inoculated or were inoculated with myeloma cells served as controls. Lung–thorax compliance was measured at various intervals after inoculation. The animals were then killed for histologic–morphometric evaluation of alveolar air expansion, inflammatory reaction in the pulmonary parenchyma, and intraalveolar edema. In the hybridoma group, the mice developed respiratory failure 9 days after inoculation, with markedly reduced lung–thorax compliance, lung congestion, alveolar collapse, hemorrhagic pulmonary edema, and hyaline membranes. Morphometric data from the same animals showed reduced volume density of alveolar air, and increased volume densities of intraalveolar “fluid” (edema) and tissue components. These lung lesions are similar to those in the adult respiratory distress syndrome.
Difficulties with tooth protectors in endotracheal intubation
Authors: Aromaa U. , Pesonen P. , Linko K. , Tammisto T.
Published: January 2009

The suitability of three tooth protectors for routine use during endotracheal intubation was studied in 300 consecutive patients undergoing elective operations under general anaesthesia. The main disadvantages of the protectors were lack of space and the consequent difficulty of guiding the endotracheal tube into the larynx, and poor visibility, especially when the Camo® protector was used. These difficulties could be avoided in most cases by cutting off the right angle of the Camo protector. The less experienced anaesthesiologists especially had difficulties with the protectors: 20% of patients in the Camo group were considered impossible to intubate unless the protector was removed. The silicone inlay of the Camo protector melts and becomes adhesive at body temperature, which makes its prolonged use hazardous. Two patients lost a maxillary incisor despite the proper use of a protector (Denex®). Thus the use of a tooth protector alone does not guarantee avoidance of dental trauma. Better results could be obtained by improving the design of the protectors and by careful pre–anaesthetic dental examination.
Dual effect of thiopentone on human granulocyte activation. Non–intervention by ketamine and morphine
Authors: Ruud B. , Benestad H. B. , Opdahl H.
Published: January 2009

The immune system, defending our organism against infections, can also cause disease. Anaesthetics may impair immunological defence by modifying the number and functions of immunocompetent cells, including the polymorphonuclear leucocytes (PMN). We have studied the effects of thiopentone, ketamine and morphine on some stimulated PMN responses that presumably reflect their microbicidal activity, i.e. oxygen consumption, aggregation, and volume increase. Stimulators were N–formyl–methionyl–leucyl–phenylalanine (FMLP, affecting cells via specific membrane receptors) and phorbol–myristate–acetate (PMA, activating protein kinase C, thereby short–cutting intramembraneous steps in normal signal transmission, and presumably provoking near–maximal cell responses with the dose applied). Preincubation of PMN with low doses of thiopentone enhanced oxygen consumption in unstimulated cells as well as in response to FMLP, but not PMA. FMLP–stimulated volume and aggregation responses were not detectably affected. The highest concentration of thiopentone depressed both oxygen uptake and volume/aggregation responses in FMLP–stimulated PMN. The amount of oxygen consumed after PMA stimulation was not affected, but both the onset of increased consumption and the maximal response were delayed. The two other drugs investigated, ketamine and morphine, did not appreciably affect oxygen consumption or aggregation by PMN: neither the baseline values nor those obtained after FMLP or PMA stimulation.
Splanchnic circulation following coeliac plexus block
Authors: Fujita Y.
Published: January 2009

Both the capacitance vessels and the resistance vessels of the splanchnic area are innervated by the sympathetic nerve fibers. We investigated the effect of abdominal visceral sympathectomy on splanchnic circulation, and the effect of altered splanchnic circulation on systemic circulation in ten mongrel dogs. Abdominal visceral sympathectomy was induced by coeliac plexus block with 1 ml/kg (body weight) of 1 % lidocaine infiltrated around the coeliac artery. Comparison was made with infiltration of physiologic saline of the same volume. The saline infiltration caused no significant changes in the hemodynamic parameters of systemic and splanchnic circulation. Mean arterial pressure decreased significantly from 18.2 ±2.0 to 14.4±1.9 kPa following the coeliac plexus block, with a concomitant decrease in the cardiac index from 2.63 ± 0.46 to 2.30 ± 0.54 1 × min‐1 × m‐2, while systemic vascular resistance was unchanged. Portal vein blood flow, hepatic artery blood flow and, therefore, splanchnic blood flow decreased by 8 to 17%. Portal vascular and hepatic artery resistances were not affected by abdominal sympathectomy. It was concluded that the capacitance vessels in splanchnic circulation are dilated during abdominal sympathetic denervation, causing a blood shift from systemic to splanchnic circulation. On the other hand, the resistance vessels in splanchnic circulation are affected little by abdominal visceral sympathectomy.
Influence of adenosine–induced hypotension on the canine myocardium rendered acutely ischaemic by artificial stenosis
Authors: ÖWall A. , Rudehill A. , Sylvén C. , Sollevi A.
Published: January 2009

An open–chest preparation was carried out in 14 pentobarbitone anaesthetized dogs in order to evaluate the myocardial effects of controlled hypotension induced by adenosine in the presence of a severe coronary stenosis that caused ischaemia of the left anterior ventricular wall. Myocardial performance, blood flow and metabolism were studied before and during a 78 ± 3% reduction of flow in the left anterior descending coronary artery (LAD) and during adenosine–induced hypotension (approximately 40% reduction of the mean arterial pressure) in the presence of the LAD stenosis. The LAD stenosis decreased the myocardial lactate uptake (P<0.01), increased ST–T segment depression (P<0.05) of the left ventricular subendocardial ECG, and reduced cardiac output by 10% (P<0.05). In the presence of stenosis, the mean arterial pressure was reduced by adenosine from 10.4 ± 0.6 kPa to 6.3 ± 0.2 kPa for 15 min. Heart rate decreased by 22% (P<0.01). There was no change in cardiac output during hypotension, while the rate–pressure product decreased by 47% (P< 0.01) and myocardial oxygen consumption decreased by 30 ±7%,. Adenosine increased the coronary sinus blood flow by 52% (P<0.01), while the LAD flow distal to the stenosis was not significantly reduced. Myocardial lactate uptake was not further reduced and subendocardial ECG signs of ischaemia were not aggravated by the hypotension. In conclusion, adenosine–induced hypotension did not aggravate the subendocardial ECG signs of acute poststenotic myocardial ischaemia. Nor did myocardial lactate determinations indicate aggravation of myocardial ischaemia. Reduced myocardial oxygen demand, as indicated by a reduced rate–pressure product and reduced myocardial oxygen consumption and heart rate, probably counteracted aggravation of ischaemia during the induced hypotension.
Severe anaphylactic reactions outside hospital: etiology, symptoms and treatment
Authors: Söreide E. , Buxrud T. , Harboe S.
Published: January 2009

Twenty–seven patients with severe anaphylactic reactions were treated by two anesthesiologist–staffed ambulance helicopters during a 5–year period. All patients had signs of respiratory and/or circulatory failure. Cutaneous symptoms were described in 70% of the patients, gastrointestinal symptoms in 30% and central nervous symptoms in 85%. Wasp sting and drugs were the most common causes. Other etiologies were bee sting, snakebite, nuts and exercise. All patients were provided with advanced pre–hospital medical care. Epinephrine was employed in 78% of the patients. I.v. fluid therapy was started in 77%. Three patients (11%) needed endotracheal intubation. The time–span from onset of symptoms to medical attendance exceeded 45 min in two patients; both died. Of the surviving patients, 23 were hospitalized. The majority had no signs of respiratory or circulatory failure on arrival in the emergency room and needed only observation in the hospital.
Antistatic treatment for reducing airborne contamination of insulating materials in intensive care
Authors: Cozanitis D. A. , Ojajärvi J. , Mäkelä P.
Published: January 2009

In an effort to reduce airborne contamination by Staphylococcus epidermidis harboured on emitted skin scales, items used in patient care were studied as regards bacterial contamination and electrical resistance. An alcoholic benzalkonium chloride sodium was used to coat stopcocks, latex drains, silicon drains and plastic covering. Static electricity did not accumulate when the insulating resistance was < 109 to 1010 ohms. Study items not treated with the antistatic solution had resistances of >2 times 1012 ohms, which decreased to 2 times 106 to 8 times 1010 ohms following antistatic treatment. The resistance of the silicon drain before and after antistatic exposure remained unchanged; an increase in its weight after treatment suggests absorption rather than the solution adhering to its surface. Statistically significantly lowered aerobic bacterial colony counts occurred from study items antistatically treated as compared to those items left untreated. The coating of an entire room and its metal contents failed to decrease bacterial contamination. The results suggest that coating of insulating objects with an antistatic solution will reduce electrical resistance and thereby airborne bacterial contamination.
Effects of macromolecular adjuvants on the duration of prilocaine
Authors: Renck H. , Hassan H. G. , Lindberg B. , ÅKerman B.
Published: January 2009

Sodium hyaluronate (HA) and dextran (Dx) of different molecular weights and concentrations were used as adjuvants to prilocaine for studies of the duration of infraorbital nerve block in the rat (IONB) and spinal anaesthesia in the mouse (SA). A positive relation was found between duration of block on the one hand and the concentration as well as the molecular weight of the adjuvant on the other. A direct relation was found between the duration of block and the viscosity of the anaesthetic solution. Low–sodium–content solutions of plain prilocaine caused a markedly prolonged duration of the most profound degrees of IONB as compared to medium– or high–sodium–content solutions, while no differences between the solutions were found for the weakest intensity of IONB studied or for SA. Solutions of low–sodium–content containing prilocaine and HA were associated with significant prolongations of IONB and SA as compared to corresponding solutions of medium– or high–sodium content. Inclusion of adrenaline, 5 μg/ml, in solutions containing prilocaine and Dx significantly prolonged the duration of the most profound degrees of IONB and of SA. By contrast, the inclusion of adrenaline in solutions containing prilocaine and HA did not prolong the duration of IONB or SA. It is concluded that modulations of the viscosity of local anaesthetic solutions by the addition of macromolecular compounds strongly affect the duration of peripheral and central nerve blocks in experimental animals. A further prolongation is accomplished by reducing the sodium content of the solutions and, in the case of Dx–containing solutions, by inclusion of adrenaline in the anaesthetic solution. The possible mechanisms of these actions are discussed.
Importance of correct handling of samples for the results of blood gas analysis
Authors: Harsten A. , Berg B. , Inerot S. , Muth L.
Published: January 2009

The importance of correct handling of samples for blood gas analysis was studied in 100 patients. Sixty minutes storage in iced water lowered pH by 0.02 pH–units. Storage at room temperature caused considerable changes in Pco2 and Po2 (+ 0.45 kPa and –1.05 kPa). Air bubbles in the syringes increased Po2 if not expelled within 30 s. Thirty minutes storage with air trapped inside the syringe caused an increase in Po2 of 1.8 kPa and a decrease in Pco2 of 0.16 kPa. The use of plastic syringes induced significant changes in Pco2 and Po2, of which the latter (+ 1.0 kPa) may be clinically significant. The findings indicate that sample collection and storage must be guarded by strict rules in order to avoid false results.
Comparison between fluctuating PEEP and conventional PEEP in dogs with lung injury induced by blood aspiration
Authors: Sato J. , Inaba H. , Uchida H. , Sakurada M. , Ohwada T. , Mizuguchi T.
Published: January 2009

It has been documented that in some patients with acute hypoxic respiratory failure the application of positive end–expiratory pressure (PEEP) may produce no improvement or even a deterioration of pulmonary oxygenation due to an increase in ventilation–perfusion mismatching. Fluctuating PEEP (F–PEEP) is a newly developed PEEP in which end–expiratory pressure (EEP) is periodically changed within a certain range. In a dog model with localized lung injury induced by the aspiration of non–heparinized blood (2 ml kg body weight‐1), F–PEEP in which the EEP was periodically changed from 0.5 to 1.5 kPa at frequencies of 10 min, and conventional PEEP with 3 different fixed EEPs, 0.5, 1.0 and 1.5 kPa (C–PEEP0.5, C–PEEP1.0 and C–PEEP1.5) were each applied for 60 min. F–PEEP produced a periodical change in Pao2 and hemodynamic variables including cardiac output, and in comparison with C–PEEP0.5, C–PEEP1.0 and C–PEEP1.5, a signficiantly greater improvement of A–aDo2 and dynamic compliance with relatively largecardiac output in the low EEP phase. These results suggest that F–PEEP is a useful mode of artificial ventilation for treating some kinds of acute hypoxic respiratory failure due to increased ventilation–perfusion mismatching.
Fluctuating PEEP (F–PEEP) versus conventional PEEP in dogs with asymmetrical lung injury
Authors: Inaba H. , Sato J. , Uchida H. , Sakurada M. , Ohwada T. , Mizuguchi T.
Published: January 2009

Fluctuating PEEP (F–PEEP) is a newly developed PEEP in which end–expiratory pressure (EEP) is periodically changed within a certain range. In a dog model with unilateral lung injury induced by the introduction of hydrochloric acid, F–PEEP in which the EEP was periodically changed from 0.5 to 1.5 kPa at periods of 6 min, and conventional PEEP (C–PEEP) with an optimized EEP of 1.0 kPa, were each applied for 30 min. F–PEEP produced a significantly greater improvement of Pao2 and intrapulmonary shunt (Qs/Qr)than C–PEEP, and at the low EEP phase, the greatest improvement accompanied by an increased dynamic compliance and a large cardiac output was obtained. These results suggest that F–PEEP provides a useful mode of artificial ventilation for the treatment of unilateral lung injury.
The cardiovascular effects of anticholinergic agents administered during halothane anaesthesia in children
Authors: Badgwell J. M. , Heavner J. E. , Cooper M. W. , Cookings E.
Published: January 2009

The cardiovascular effects of anticholinergic agents administered during halothane anaesthesia were studied in 31 children aged 1–12 years undergoing peripheral orthopaedic surgery. Either normal saline, glycopyrro–late (10 μg–kg‐1) or atropine (20 μg–kg‐1) was administered in randomized double–blind fashion during the induction of anaesthesia with halothane while the electrocardiogram was continuously recorded. After induction, the children were paralyzed with atracurium, intubated, and ventilated. Anaesthesia was maintained with N2O/O2 and halothane (up to 2.5% inspired). The concentrations of expired CO2 and halothane were measured continuously using mass spectrometry. Sixty–one percent (19/31) of the children developed one or more dysrhythmias. Junctional rhythm occurred in 74% (14/19) of the children with dysrhythmias, developed early during induction (mean ± s.d. time = 2.29 ± 2.0 min after commencement of induction), and usually resolved before the administration of the study drug (8/14). All dysrhythmias initially occurred before or during induction and none developed during intubation, during incision, during the maintenance of anaesthesia, or after the administration of anticholinergic agents. The data suggest that: 1) a combination of factors present during halothane induction is highly dysrhythmogenic especially for junctional rhythm; 2) junctional rhythm will resolve spontaneously; 3) the administration of an anticholinergic agent during halothane induction is safe but may be unnecessary in children > 1 year of age; and 4) the dysrhythmogenic factors present during induction are attenuated during the maintenance of halothane anaesthesia.
Elimination of waste anaesthetic gases from operating theatres
Authors: Kann T. , Breum N. O.
Published: January 2009

At present, waste anaesthetic gases in the operating theatre are eliminated by room ventilation and by–additional measures such as scavenging by a double–mask system and a local exhaust system. A simple technique is proposed for measuring the capture efficiency (E) of different scavenging systems. E is the ratio of the waste anaesthetic gases captured by a system to the total quantity of waste anaesthetic gases produced. In a field study on existing unmodified systems, E from a phantom pollutant source was measured using a portable measuring unit designed for displaying test results on location. The pollutant source was a leaking double–mask system. When scavenging from the double–mask system, E was 98% at an exhausted airflow of 28–33 m3/h. Using a local exhaust system at an airflow of 30 m3/h, E ranged from 20 to 96%, depending on the distance between the mask and the nozzle of the exhaust system.
Effects of thoracic epidural analgesia with morphine or bupivacaine on lower oesophageal motility – an experimental study in man
Authors: Thorén T. , Carlsson E. , Sandmark S. , Wattwil M.
Published: January 2009

Lower oesophageal peristalsis and lower oesophageal sphincter (LOS) pressure during thoracic epidural analgesia (TEA) were studied in 20 healthy volunteers. After oesophageal manometric baseline recordings, 10 volunteers received 4 mg epidural morphine. The other ten received 0.5% bupivacaine epidurally in sufficient amounts to block the sympathetic innervation of the oesophagus. Thereafter oesophageal manometry was repeated. During epidural morphine oesophageal peristalsis, resting LOS pressure and the contraction of LOS after swallowing did not change, but the relaxation of the LOS in response to swallowing decreased significantly (P< 0.01). Following TEA with bupivacaine, neither distal oesophageal peristalsis nor LOS pressure changed.
Assessment of neuromuscular transmission by the evoked acceleration response
Authors: Werner M. U. , Nielsen H. Kirkegaard , May O. , Djernes M.
Published: January 2009

This paper presents preliminary observations on an acceleration–responsive transducer designed to monitor neuromuscular transmission. Simultaneously evoked acceleration and tension responses of the adductor pollicis muscles were studied. Registrations were obtained during recovery from atracurium–induced block in 29 individuals in neurolept II anaesthesia (Group I) and in 4 ICU patients (Group II) sedated with pentobarbital or midazolam. Regression analysis of 1567 train–of–four (TOF) registrations, in regard to TOF–ratio (T4/T1) and first twitch ratio (T1/T0), demonstrated regression coefficients (b) and correlation coefficients (r) in the range 0.91‐1.06 and 0.89‐0.98, respectively. During 1 Hz single twitch stimulation and post–tetanic count stimulation, b and r were in the range 0.85‐1.03 and 0.77‐0.90, respectively. Following administration of edrophonium (n = 6, Group I) a deviation of T1/T0 regression values was observed in four individuals, i.e. 0.48 (b) and 0.56 (r). This investigation proved a good level of accuracy of the acceleration transducer compared to the force displacement transducer during spontaneous and neostigmine–induced recovery from atracurium block. The acceleration transducer–based system does not require a rigid suspension and seems to have a good monitoring potential in clinical assessment of neuromuscular transmission.
Slowing of the heart during anaphylactic shock
Authors: J. Jacobsen M.D.  , Secher N. H.
Published: January 2009

Five patients are reported with anaphylactic shock reactions due to i.v. administration of atracurium, methicillin, amidotrezoate (n = 2) and plasma. In these patients a fall in heart rate (HR) from 5–50 beats min‐1 was recorded during the hypotensive period. In three of the patients HR was 40 beats min‐1 or less, and in two of the patients a hypotensive bradycardiac episode spontaneously reappeared after normal HR and BP were established. Central venous pressure (CVP) fell in one patient from 0.8 to 0.6 kPa as HR and BP decreased while arterial oxygen tension remained normal. All patients were in a stable condition after treatment with volume expansion and sympathomimetic drugs. These observations indicate that anaphylactic shock is associated with a strong and sometimes persistent vagal tone to the heart in parallel with the early reaction to hypotensive hypovolaemic shock.
Effect of epidural analgesia on immediate posttraumatic cardiovascular hemodynamics and pulmonary platelet trapping
Authors: Blomquist S. , Elmér O. , Thörne J.
Published: January 2009

Immediate reactions to different types of trauma have been the object of several studies recently. Thus, it has been shown that pulmonary platelet trapping (PPT) occurs within minutes after both septic and traumatic shock following soft tissue trauma. To study whether block of the nervous supply to the traumatized tissue had any effect on PPT, 40 mg of mepivacaine was injected through an epidural catheter inserted between the second and third lumbar vertebrae in pigs. After a period of stabilization the animals were subjected to a standardized soft tissue trauma to the hind limbs. A group of animals without an epidural catheter served as control. The trauma induced a profound decrease in cardiac output and mean arterial pressure. Pulmonary platelet trapping was recorded dynamically by labelling platelets with radioactive indium. Trapping of platelets in the lungs occurred immediately after the trauma, and there was no difference in animals pretreated with epidural block compared with the control animals. Our findings indicate that the trapping of platelets after soft tissue trauma is triggered at the trauma site and not affected by a block of the nervous supply to the trauma sites, including the peripheral sympathetic outflow.
Flumazenil in total intravenous anaesthesia using midazolam and fentanyl
Authors: Klausen N. O. , Juhl O. , Sørensen J. , Ferguson A. H. , Neumann P. B.
Published: January 2009

Forty patients, scheduled for elective surgery in a thoracic and vascular surgical unit, were anaesthetized by a total intravenous anaesthesia technique using midazolam and fentanyl. Subsequent reversal of anaesthesia by the specific benzodiazepine antagonist flumazenil was evaluated in a double–blind trial. The patients were observed in the recovery room postoperatively until the next morning, and their recovery was repeatedly evaluated during the first 240 min after anaesthesia. Six patients in the placebo group required an oral airway or an endotracheal tube during the first hours of recovery, whereas none who received flumazenil did. The respiratory rate was significantly higher after flumazenil than placebo during the first 4 h postoperatively (Anova, P < 0.01). Blood pressure and heart rate were not different between the two groups. The degree of sedation, orientation in time and space and the ability to cooperate were significantly superior after flumazenil than placebo (Anova, P < 0.01). Some degree of resedation was observed in both groups, affecting 95% of the patients who received flumazenil against 30% after placebo (Mann–Whitney, P < 0.05). No adverse reactions attributable to the use of flumazenil were encountered.
Reversal of flunitrazepam sedation with flumazenil. A randomized clinical trial
Authors: Riishede L. , Krogh B. , Nielsen J. Lyhne , Freuchen I. , Mikkelsen B. O.
Published: January 2009

Fifty–nine male patients scheduled for transurethral resection of the prostate under flunitrazepam sedation and spinal analgesia were randomized in a double–blind trial to reversal of sedation with either the benzodiazepine antagonist flumazenil or placebo. Judged by degree of sedation, comprehension and cooperation as well as by estimation of orientation in time and space, flumazenil was superior to placebo (P < 0.001). The median duration of anterograde amnesia was 16 min after flumazenil and 75 min after placebo (P < 0.001). Adverse events were more frequent with placebo (P > 0.05), while no differences were evident with regard to laboratory data or cardiorespiratory function.
Hemodynamic changes during laparoscopy with positive end–expiratory pressure ventilation
Authors: Ekman L. G. , Abrahamsson J. , Biber B. , Forssman L. , Milsom I. , Sjöqvist B. A.
Published: January 2009

Hemodynamic measurements were performed in 10 healthy women undergoing elective laparoscopy for the investigation of infertility. A standardized anesthetic technique which included the application of positive end–expiratory pressure (PEEP), 0.49 kPa (3.7 mmHg) was utilized. The following variables were studied: cardiac output, stroke volume and left ventricular ejection time (determined non–invasively with impedance cardiography), heart rate, blood pressure, total peripheral vascular resistance and end–tidal carbon dioxide (ET–CO2). The combination of 25 head–down tilt and PEEP ventilation during laparoscopy was associated with a pressure response that restored arterial pressures to essentially pre–anesthetic levels. Net cardiac effects were small. With this regime low pressure 0.7–1.1 kPa (5–8 mmHg) intra–abdominal insufflation with CO2 was associated with only minor cardiovascular changes. There were no indications that 0.49 kPa PEEP during laparoscopy produced adverse cardiovascular effects. The application of PEEP reduced (P < 0.001) ET–CO2. There was no net increase in ET–CO2 after CO2–insufflation compared to the measurement after induction of anesthesia. This is in contrast to earlier studies without PEEP where a significant net increase in ET–CO2 was reported after CO2–insufflation.
Effects of dopamine on the portal circulation after therapeutic hepatic artery ligation
Authors: Winsö O. , Biber B. , Fornander J. , Gustavsson B. , Holm C. , Häggendal J. , Milsom I.
Published: January 2009

The effects of exogenous dopamine (2, 4 and 6 μg–kg‐1 min‐1 i.v.) on the portal circulation were studied in six patients following therapeutic hepatic artery ligation. Portal blood flow (PBF) was measured by the continuous thermodilution technique. Portal venous pressure (PVP, n = 3) was monitored through the thermodilution catheter to allow derivation of preportal vascular resistance (PVR). Blood samples were taken through the portal venous catheter for measurement of dopamine. A significant increase in PBF and a decrease in PVR were observed during graded i.v. dopamine infusion. Thus, PBF was 961 ± 119 ml min‐1 during control conditions and increased to 1446 ± 221 ml min‐1 during the dopamine infusion at 6 μg kg‐1 min‐1. No significant changes in mean arterial pressure or PVP were observed during dopamine administration. The pharmacokinetics of dopamine did not differ from that previously reported in patients with an intact arterial supply. In conclusion, our data indicate that exogenous dopamine consistently increases PBF by preportal vasodilation, also in patients with a surgically restricted hepatic arterial blood supply.
Prolonged elimination of midazolam after i. m. administration
Authors: Rærder J. C. , Nilsen O. G.
Published: January 2009

The elimination pharmacokinetics of midazolam after i.m. administration was compared with combined i.m. and i.v. administration in a randomized study of 55 gynaecological patients in outpatient general anaesthesia. Group 1 (n = 40) received midazolam 0.1 mg/kg i.m. as premedication 45 min before induction of general anaesthesia with midazolam 0.3 mg/kg i.v. Group 2 (n= 15) received midazolam 0.1 mg/kg i.m. as premedication 45 min before induction of general anaesthesia with thiopentone 4 mg/kg. Serum midazolam concentration measurements were performed regularly post–induction for 7 h in each patient. The elimination half–life of midazolam after i.m. administration (Group 2) was 6.6 ± 1.2 h (mean ± s.e. mean), which was significantly longer (P < 0.05) than the 3.9 ± 0.3 h observed after the combined i.m. and i.v. administration of midazolam (Group 1), and significantly longer than 2.9 h obtained from a calculated i.v. administration curve. We postulate a slow i.m. depot release of midazolam, representing the rate–limiting step in the elimination of midazolam after i.m. administration.
Subarachnoid versus epidural bupivacaine 0.5% for caesarean section
Authors: Hansen S. Helbo , Bang U. , Garcia R. S. , Olesen A. S. , Kjeldsen L.
Published: January 2009

In order to compare subarachnoid (spinal) and epidural block for caesarean section, 40 women were randomly allocated to spinal or epidural analgesia with bupivacaine. The median dose of bupivacaine was 13 mg in the spinal group versus 155 mg in the epidural group. The mean time from induction to delivery was 32 min shorter in the spinal group (P < 0.001). In the spinal group one woman was excluded because of spontaneous labour. Three patients in the spinal and one in the epidural group failed to develop adequate analgesia to initiate surgery. For the remaining patients both techniques provided good analgesia during operation. Postoperatively, epidural block provided better pain relief. The patients in the epidural group had a lower pain score during the first 4 h after the operation (P <0.01). In spite of similar haemodynamic changes in the two groups, the mean base deficit in umbilical cord blood at delivery was higher in the spinal group (P <0.05).