bluuebunny/crossref_metadata_2025 huggingface dataset:
Intravenous propofol vs thiamylal‐isoflurane for caesarean section, comparative maternal and neonatal effects
Authors: Abboud T. K. , Zhu J. , Richardson M. , Silva E. Peres Da , Donovan M.
Published: January 2009

Several studies on propofol (Diprivan) for induction of anaesthesia during caesarean section have demonstrated its safety, however, its safely during maintenance of anaesthesia is not yet fully evaluated.

The present study was undertaken to compare the maternal and neonatal effects of propofol or isoflurane in 74 term parturients undergoing primary or repeat caesarean section. Patients were randomly assigned to two groups, propofol group (n = 37) received propofol 1.5–2.5 mg·kg‐1 for induction followed by a continuous infusion of propofol of 0.05–0.2 mg 4mD kg‐1· min‐1. The isoflurane group (n=37) received thiamylal 3–4 mg · kg‐1 for induction followed by isollurane 0.25–0.75% for maintenance. All patients had rapid sequence induction using suceinyl‐choline and endotracheal intubation, 50% N2O and O2 were used in all patients until delivery. After delivery N2O concentration was increased to 67% and intravenous butorphanol (Stadol) was given as needed. Patients in the propofol group had less hypertension after intubation (P<0.05) and this was also of shorter duration compared to patients in the isoflurane group (5 min vs 10 min respectively). Maternal blood loss as well as intraoperative awareness and recovery time did not differ significantly between the two groups. Neonatal status as ascertained by Apgar scores, cord acid base status and the neurological and adaptive capacity scores (NACS) was equally good in both groups. It is concluded that propofol used for induction and maintenance of anaesthesia is a safe alternative to thiamylal/isoflurane for patients undergoing caesarean section and is associated with less hypertensive response during laryngoscopy and intubation.
Prilocaine reduces injection pain caused by propofol
Authors: Eriksson M.
Published: January 2009

Propofol, which is commonly used for outpatient anaesthesia, may evoke pain during infusion. Forty‐eight patients (ASA I‐II) undergoing elective uterine dilatation and curettage received randomly in a standardised fashion: A: Propofol mixed with prilocaine; B: Propofol and lidocaine; C: Propofol with prilocaine + lidocaine (equal amounts) or D: Propofol and saline. The final ratio of propofol: local anaesthetic/saline was 9: 1 in all mixtures. Pain on injection was significantly decreased in the three groups receiving propofol and local anaesthetic(s) compared to the one given propofol and saline. Propofol is required in greater amounts when mixed with lidocaine than when mixed with saline. A binding between the algesic part of the propofol molecule and the local anaesthetic agent may explain these findings. Another twenty‐two comparable patients were given 30 mg of ketorolac or an equal volume of saline intramuscularly 45 60 minutes prior to propofol. Ketorolac given before propofol did not reduce pain on injection. This indicates that inhibition of the cyclooxygenase pathway of arachidonic acid metabolism does not play a major role in the reduction of this pain.
Potency and maintenance requirement of atracurium and vecuronium given alone or together
Authors: Rautoma P. , Erkola O. , Meretoja O. A.
Published: January 2009

A synergism exists between some competitive muscle relaxants. However, maintenance requirement of a combination of muscle relaxants has been evaluated only in paediatric patients. We studied 45 elective adult surgical patients (ASA I‐II) during propofol‐alfentanyl‐N2O‐O2‐anaesthesia. The first 30 patients were randomized to receive either atracurium or vecuronium to create individual dose‐response curves for these muscle relaxants. ED95‐values for atracurium and vecuronium were 260±9 and 59±3 μg · kg‐1, respectively (mean±s.e.mean). Requirements of atracurium and vecuronium to maintain an 85–95% neuromuscular blockade were 301 and 83 μg kg‐1 h‐1, respectively. An additional 15 patients received a combination of atracurium and vecuronium (cAV) in an equipotent dose ratio. An ED95 of a cAV was 94± 7 μg · kg‐1 of atracurium together with 21±2 μg · kg‐1 of vecuronium, or 72±6% of one ED95 dose of a parent agent. Potentiation was significant (P=0.0001). A maintenance requirement of a cAV was 120 μg kg‐1 h‐1 of atracurium together with 27 μg kg‐1 h‐1 of vecuronium. Thus, a significant potentiation was maintained also during the course of anaesthesia. A cAV had an effect like one intermediate‐acting agent. If a cAV is used instead of using atracurium or vecuronium alone, the maximal reduction of drug consumption would be approximately 30%.
Does colloid‐induced plasma hyperviscosity in haemodilution jeopardize perfusion and oxygenation of vital organs?
Authors: Krieter H. , Brückner U. B. , Kefalianakis F. , Messmer K.
Published: January 2009

Background and Methods. The infusion of dextran solutions is associated with haemodilution and, under some conditions, with a slight increase in plasma viscosity. To clarify the compound effects of simultaneous haemodilution and plasma viscosity increases on macro‐ and microhaemodynamics, we investigated the changes in arterial perfusion (radiolabelled microspheres, 15 μrn Ø) and oxygenation (tissue Po2) of vital organs using an animal model of plasma hyperviscosity. In nine splenectomized beagles plasma viscosity was increased step by step from 1.06 (baseline) to 2.14, and 2.99 mPas by infusion of small amounts (4% of total blood volume) of an ultra‐high‐molecular‐weight dextran (50% w/v, mw: 500,000).

Results. Despite the significant increase in plasma viscosity, cardiac output as well as specific organ blood flows in heart, brain, liver, and muscle rose steadily with each step of viscosity, while the haematocrit declined from 0.31 to 0.24 and 0.20, respectively. Medians of tissue Po2 in liver peaked at a viscosity of 2 mPa.s and returned to baseline values at 3 mPa.s, whereas in non‐working skeletal muscle Po2 values were maximal at 3 mPa.s.

Conclusion. These results indicate that the impact of plasma viscosity on the rheological properties of whole blood is completely offset by die concomitant reduction of haematocrit. Thus, the comparatively minor changes in plasma viscosity observed after prolonged use of clinical dextrans and other colloids in no way compromise the perfusion and oxygenation of vital organs.
Comparison of cardiac output measurement techniques: thermodilution, Doppler, GO2‐rebreathing and the direct Fick method
Authors: Espersen K. , Jensen E. W. , Rosenborg D. , Thomsen J. K. , Eliasen K. , Olsen N. V. , Kanstrup I‐L.
Published: January 2009

Simultaneously measured cardiac output obtained by thermodilution (TD), transcutaneous suprasternal ultrasonic Doppler (DOP), CO2‐rebreatliing (CR) and the direct Fick method (FI) were compared in eleven healthy subjects in a supine position (SU), a sitting position (SI), and during sitting exercise at a workload of 50 W (EX). The agreements between the techniques, two by two, were expressed as the bias calculated as the averaged differences between the techniques. Precision was expressed as the standard deviation of the bias. The overall agreement (bias±precision) between TD, DOP and CR respectively and FI were 2.3±1.6. ‐0.1 ±1.4, and ‐0.2±1.1 1/min. TD overestimated cardiac output consistently in SU, SI and EX. DOP was in‐accurate during EX and agreed well with FI in SU and SI. CR agreed closely with FI in SI and EX, but values were underestimated in SU. The overall agreement between DOP and CR, respectively, and TD were 2.5±2.2 and 2.6±1.6 1/min. The overall agreement between DOP and CR was 0.1 ± 1.6 1/min. In conclusion, TD overestimated cardiac output compared to the other techniques and the poor agreement has to be taken into consideration especially in measures of low values. The precision of DOP and CR against FI seems to be within clinically acceptable limits, and these methods may provide interchangeable alternatives to the invasive Fick method.
Ethanol monitoring of irrigating fluid absorption in transcervical resection of the endometrium
Authors: Olsson J. , Hahn R. G.
Published: January 2009

Background. We evaluated the precision in using ethanol to indicate and quantify absorption of irrigating fluid during transcervical resection of the endometrium.

Methods. The ethanol concentration in the expired breath, the serum sodium level, the blood loss and the volumetric fluid balance were measured over 10‐min periods during 62 operations. A solution containing glycine 1.5% and ethanol 1% was used to irrigate the uterus.

Results. Most principles previously outlined for ethanol monitoring in transurethral prostatic surgery could also be applied in endometrial resection.

In the 21 patients who showed the intravascular pattern of ethanol changes, the breath alcohol measurement corrected for absorption time predicted the volume of irrigant absorbed {up to 2,531 ml) with a standard error of 230 ml at the end of any 10‐min period of absorption. Repeated measurement of serum sodium indicated intravascular fluid absorption with practically the same precision as the breath test.

Extravascular absorption was found in 14 patients. In these operations, the volume of irrigant absorbed (up to 1,767 ml) could be predicted with a standard error of 92 ml from the ethanol concentration at the plateau level attained after absorption had occurred.

Conclusion. Ethanol monitoring is precise enough to allow monitoring of irrigating fluid absorption in endometrial resection.
Prolonged interference of blue dye “patent blue” with pulse oximetry readings
Authors: Saito S. , Fukura H. , Shimada H. , Fujita T.
Published: January 2009

Several blue dyes were reported to interfere with the accurate determination of oxygen saturation by pulse oximetry. However, in previous reports the interferences were observed only for a short duration. We have experienced a case in which the interference by a blue dye, “patent blue” continued for a long time. It was suggested that the blue dye, when it was injected intra‐arterially and in an anaemic patient, interfered with the pulse oximetry measurement to a greater extent.
Blood‐stained pleural effusion complicating interpleural analgesia
Authors: Khor K. E. , Josephson M. A.
Published: January 2009

A case of blood‐stained pleural effusion complicating interpleural analgesia for a difficult nephrectomy is reported. We describe our technique of placement of the interpleural catheter. Interpleural infusion of 0.25% bupivacaine at 7 mls/h provided excellent postoperative analgesia. However, a left pleural effusion was demonstrated from chest X‐ray films taken from the third day post‐operatively. Persistent low grade fever and a large pleural effusion necessitated drainage which resulted in improvement in symptoms. Possible aetiologies of the effusion are discussed, although the exact cause was uncertain. Observation for a developing pleural effusion and other complications should form part of the postoperative observation and if one does develop, the necessary measures can be taken.
Hyaluronan in sepsis
Authors: Berg S
Published: January 2009

Abstract: Sepsis and septic shock are important causes of morbidity and mortality in the intensive care unit (ICU). Mortality rates in septic shock are estimated to be 40‐5O%, in spite of modrn intensivc care. Death is commonly caused by cardiovascular collapse and multiple organ dysfunction syndrome (MODS). Hepatic dysfunction is a common component of MODS. and can have a major impact on prognosis and survival. Sepsis is, among other derangements, also accompanied by disturbed tissue water homeostasis with increased extravasation of water resulting in tissue oedema.

Hyaluronan is an interstitial macromolecule that participates in the regulation of tissue hydration. It is normally present in small concentrations in the blood, and is rapidly cleared from the blood by the liver endothelial cells. The synthesis of hyaluronan can be stimulated by inflammatory mediators. Thus sepsis and hyaluronan turnover could interact in many ways. The aim of the present investigations was to study possible changes in circulating hyaluronan concentrations in relation to sepsis and septic shock.

Plasma levels of hyaluronan were studied in 44 patients with infections and septic shock. Increased plasma concentrations were found, and the increase correlated to disease severity and outcome. In experimentally induced sepsis in pigs, an increase in circulating concentrations was found, and a relation to haemodynamic instability and outcome was seen. A moderate increase in blood hyaluronan concentrations was seen after surgical trauma in both humans and pigs. Crystalloid infusion therapy also caused a small increase in plasma hyaluronan concentrations in healthy volunteers, probably through an increased washout of interstitital hyaluronan. The hepatic turnover of hyaluronan was studied in septic shock patients. Low extraction ratios at high circulating concentrations were found, suggesting a reduced capacity of hepatic uptake and an increased inflow to the circulation. The kinetics of plasma turnover of hyalurorian were studied in septic and non‐septic ICU patients. A prolonged half‐life was seen among the septic patients, suggesting a reduced clearance capacity.

In conclusion, sepsis is accompanied by increased circulating hyaluronan concentrations. The magnitude of thc increase seems to correlate to disease severity and outcome. The cause of this increase is suggested to be both reduced hepatic uptake function, and increased input to the circulation. The relative contribution of these mechanisms, and the possible clinical utility of plasma hyaluronan measurements, remain to be determined.
Epidural anaesthesia blocks changes in peripheral lymphocytes subpopulation during gastrectomy for stomach cancer
Authors: Hashimoto T. , Hashimoto S. , Hori Y. , Nakagawa H. , Hosokawa T.
Published: January 2009

To examine the effects of surgery and anaesthesia on cell‐mediated and humoral immunity, we investigated changes in subpopulations of peripheral T cells and B cells during gastrectomy. Twenty‐one patients with gastric cancers who underwent total or subtotal gastrectomy were randomly assigned to receive thiopental/N2O general anaesthesia supplemented with either epidural (epidural group, n=12) or enflurane(enflurane group, n=9). The changes in peripheral lymphocyte subpopulations were detected and quantified using single and double label analysis of monoclonal antibodies against lymphocyte membrane surface markers (Leu series). Subpopulations were measured before induction, and 1 and 2 hours after skin incision. In the enflurane group, B cells (Leu12+), total T cells (Leu4+), inducer T cells (CD4+, Leu8+) and the CD4/CD8 ratio decreased and suppressor T cells (CD8+, Leu15+) increased significantly after skin incision. Whereas, the epidural group showed no change in the number of B cells and each T cell subpopulation during the study. These data suggest that epidural anaesthesia blocks the effect of stress induced by major surgery on fluctuation of peripheral lymphocyte subpopulations which may be associated with suppression of immunity.
Protective effects of halothane but not isoflurane against global ischaemic injury in the isolated working rat heart
Authors: Sahlman L. , Waagstein L. , Haljamäe H. , Ricksten S.‐E.
Published: January 2009

The effects of equi‐anaesthetic concentrations of halothane (HAL) and isoflurane (ISO) on myocardial performance, perfusion, oxygenation and lactate release were studied before, during and after a low‐flow, global ischaemic insult in isolated, paced rat left heart preparations. An antegrade perfusion technique was used, where left atrial pressure (LAP) and mean aortic pressure (MAP) could be altered independently of each other. Aortic flow, coronary flow (CF) and PO2 in venous coronary effluent were continuously recorded and stroke volume, myocardial oxygen consumption (MVO2) and myocardial oxygen extraction as well as lactate release were calculated. The hearts were exposed for at least ten minutes to the perfusate without (control, n=10) or with HAL (n=10) or ISO (n= 10) at a MAP of 80 mmHg (10.4 kPa) and a LAP of 7.5 mmHg (1.0 kPa). After baseline measurements, MAP was reduced to 25 mmHg (3,2 kPa) for a total of nine minutes. Thereafter MAP was increased to 80 mmHg (10.4 kPa) for another nine minute period. During the whole experimental procedure, LAP was maintained at 7.5 mmHg (1.0 kPa) and heart rate at 325 beats per minute. In the pre‐ischaemic control period, MVO2 was lower with HAL compared to ISO (P<0.05) and control (P<0.05). Stroke volume was also lower with HAL compared to control (P<0.05). During hypoperfusion, lactate release was twice as high in the control group (P<0.0I) and with ISO (P<0.01) compared to HAL. This was accompanied by a lower oxygen extraction with HAL compared to control (P<0.05) and ISO (P<0.05). In the post‐ischaemic periods, MVO2 and stroke volume were lower with HAL compared to ISO and control. There were no significant differences in CF between the groups. We conclude that HAL, but not ISO, exerts a direct protective effect against a glycon'c anaerobic metabolism during low‐flow global myocardial ischaemia.
Attenuation of hyperoxic lung injury in rabbits with superoxide dismutase: effects on inflammatory mediators
Authors: Mikawa K. , Nishina K. , Maekawa N. , Obara H.
Published: January 2009

Background. Superoxide dismutase (SOD) has been shown to attenuate hyperoxic lung injury. This effect is thought to be exhibited by scavenging superoxide released from neutrophils and other aerobic cells. The aim of the current study was to investigate the effect of pre‐treatment with SOD on the chemical mediators in hyperoxic lung injury.

Methods. Thirty male anesthetized rabbits were allocated to receive one of three treatments (n = 10 for each group): ventilated with 100% oxygen for 36 h with or without recombinant human SOD (rhSOD) treatment, and ventilated with air for 36 h without rhSOD. In the rhSOD‐treated group, a single intravenous dose of rhSOD 10,000 U kg BW‐1was administered immediately after the start of exposure to 100% oxygen and thereafter infused at a rate of 340,000 U kg BW‐1day‐1for 36 h until the animals were sacrificed. The lungs of all rabbits were ventilated with 100% oxygen or air. Haemodynamics, Pao2, and lung mechanics were recorded during the ventilation period. After exposure to 100% oxygen, lung mechanics, cell fraction of bronchoalveolar lavage fluid (BALF), activated complements, cytokines, and arachidonic acid metabolite concentrations in BALF were measured and analyzed. The lung wet‐to‐dry (W/D) weight ratio and albumin concentrations in BALF were determined as indices of pulmonary oedema.

Results. Exposure to the high concentration of oxygen for 36 h caused no significant changes in haemodynamics but decreased compliance and increased A‐aDo2. In the rhSOD‐treated group, the decrease in compliance was not observed. At the end of the 36 hrexposure period, however, hyperoxia significantly increased the lung W/ D weight ratio, influx of neutrophils into the lung, BALF concentrations of C3a, C5a, tumor necrosis factor‐α, interleukin (IL)‐1β, IL‐6, IL‐8, thromboxane B2, and albumin. Pre‐treatment with rhSOD attenuated these increases. Exposure to 100% oxygen caused extensive morphologic lung damage (alveolar haemorrhage and hyaline membrane formation), which was lessened by rhSOD.

Conclusion. These results indicate that intravenous rhSOD prevented hyperoxic lung injury (decreases in Pao2and compliance, increased pulmonary vascular permeability, histopathological damage) in rabbits. This prophylactic effect of rhSOD amy be due, in part, to decreased chemical mediators such as activated complements, cytokines, and arachidonic acid metabolites.
Autogenous production of hydroxyl radicals from thiopental
Authors: Okutomi T. , Nomoto K. , Nakamura K. , Goto F.
Published: January 2009

It is generally believed that barbiturates can protect neural tissues from the damage induced by cerebral hypoxia. One of the mechanisms for protecting neurons is through the inhibition of lipid peroxidation (LPO). We therefore examined LPO in rat brain, liver and kidney by measuring the accumulation of thiobarbituric acid‐reactive substances (TBAR) after thiopental administration under 21% O2. We also designed an in vitro study to gain insight into free radical generation leading to the formation of LPO from thiopental by electron spin resonance (ESR). An accumulation of TBAR in the rat liver was observed after the administration of a large dose of thiopental (70 mg/kg intraperitoneally). However, no change in LPO in the brain and kidney was observed. In the in vitro study, thiopental could scavenge superoxide (O2‐) radicals, while it spontaneously generated hydroxyl radicals (·OH) in solution. We conclude that thiopental can scavenge O2‐, while producing ·OH, subsequently resulting in membrane lipid peroxidation under physiologic O2 conditions. This formation of ·OH may damage cell membrane lipids.
Effects of hypotensive treatment with α2‐agonist and β1‐antagonist on cerebral haemodynamics in severely head injured patients
Authors: Asgeirsson B. , Grände P.‐O. , Nordström C.‐H. , Berntman L. , Messeter K. , Ryding E.
Published: January 2009

Therapy of post‐traumatic brain oedema often includes preservation of high arterial blood pressure to avoid secondary ischaemic injuries to the brain. This practice can be questioned since high arterial blood pressure may aggravate brain oedema through raised hydrostatic capillary pressure, causing fluid filtration across the damaged blood‐brain barrier. This latter view is in agreement with our clinical experience and therefore hypotensive therapy with an α2‐adrenergic agonist (clonidine) and a β1‐adrenergic antagonist (metoprolol) has become part of our treatment protocol for severely head injured patients to decrease the post‐traumatic brain oedema. The present study is an attempt to analyse whether there are any direct local cerebrovascular effects of the hypotensive agents used, which also might influence intracranial pressure. Severely head injured patients were investigated. Heart rate, mean arterial blood pressure, intracranial pressure, cerebral blood flow and arterio‐venous difference in oxygen content were measured before and after a bolus dose of clonidine (six patients) and metoprolol (nine patients).

Clonidine decreased mean arterial blood pressure and cerebrovascular resistance without affecting other parameters measured. Metoprolol decreased heart rate and mean arterial pressure, but had no effect on the cerebrovascular parameters.

The results show that clonidine and metoprolol have no, or only minor, direct influence on local cerebral haemodynamics in severely brain injured patients. This implies that if there is an intracranial pressure reducing effect of these drugs, as suggested, this must be due to other mechanisms, namely a reduction in capillary hydrostatic pressure secondary to decreased arterial blood pressure and heart rate.
Oral premedication one hour before minor gynaecological surgery — does it have any effect?
Authors: Jakobsson J. , Rane K. , Ryberg G.
Published: January 2009

The purpose of the present study was to compare the effects of oral premedication with ketohemidone 5 mg, lorazepam 1 mg, propranolol 40 mg or placebo, given about an hour prior to anaesthesia, in a prospective randomized double‐blind fashion. One hundred and twenty ASA I female patients scheduled for elective laparos‐copy were randomly prescribed one of the study drugs. Patient evaluation of anxiety, nurse evaluation of premedication, induction and postoperative course were studied. Ninety‐three of the 120 patients (78%) experienced no change or a decrease in anxiety, regardless of type of active drug or placebo administered. Eighty‐eight of the patients (73%) were considered adequately premedicated by the nurse observer, with no differences between the groups. Pre induction pulse rate, blood pressure and amount of induction agent needed was also similar between the four groups of patients. No major differences could be seen during the postoperative course. We found no major effects of any of the active drugs studied compared to placebo. Routine use of small doses of oral premedication one hour before elective surgery among low anxiety patients could probably be omitted.
Healthy lungs tolerate repetitive collapse and reopening during short periods of mechanical ventilation
Authors: Taskar V. , John J. , Evander E. , Wollmer P. , Robertson B. , Jonson B.
Published: January 2009

The possible occurrence of lung damage if alveolar units are allowed to collapse and reopen breath by breath during mechanical ventilation with normal tidal volumes was investigated. Anaesthetised, paralysed, open chest rabbits were subjected to either intrathoracic negative (NEEP; n=6) or positive (PEEP; n=6) end‐expiratory pressure during volume controlled mechanical ventilation. Both experimental settings were preceded by a 30 min control period and followed by a 30 min recovery period during which a PEEP of 0.2 kPa was maintained. Pao2 and pulmonary compliance deteriorated significantly in the NEEP group during the experimental period and compared to ventilation with PEEP. Partial restoration of lung mechanics and blood gases was achieved during the recovery period. After an alveolar recruitment manoeuvre, this recovery was complete. Lung clearance studied by depositing an aerosol of technetium‐99m‐labelled diethylenetriamine pentaacetate (99mTc‐DTPA) in the alveoli, was significantly faster during ventilation with NEEP compared to the PEEP group (P=0.0002) as well as the control period (P= 0.0029). It did not recover completely during the recovery period but remained significantly faster. light microscopic histology was normal in both groups with no evidence of inflammation or epithelial disruption. We conclude that previously healthy rabbit lungs show only a transient disturbance of lung mechanics and blood gases with repetitive collapse and re‐expansion. The integrity of the alveolar rnicrostructure is preserved. The disturbance in the alveolo‐capillary permeability persists and may indicate surfactant related alveolo‐capillary barrier dysfunction.
Erythrocyte counts in the cerebrospinal fluid associated with continuous spinal anaesthesia
Authors: Lindgren L. , Silvanto M. , Scheinin B. , Kauste A. , Rosenberg P. H.
Published: January 2009

Continuous spinal anaesthesia technique can be associated with peridural haemorrhage due to blood vessel damage caused by the needle or the catheter. We studied whether thrombosis prophylaxis or anticoaguladon medications increase the risk of subarachnoid haemorrhage when continuous spinal anaesthesia is used. Twenty arthroplasty patients received low‐molecular‐weight heparin preoperatively and twenty‐two vascular surgery patients received heparin (100 IU kg‐1) peroperatively; eight of the latter patients were on regular preoperative antiplatelet medication. Twenty‐four prostate surgery patients, not exposed to heparin or other drugs affecting coagulation, served as controls. A 22‐gauge spinal catheter was used and bupivacaine was injected through the catheter. Within the following 24 hours, 4—5 cerebrospinal fluid samples were collected for erythrocyte counts. In the arthroplasty and the vascular group there were five patients each and in the control group seven patients with more than 100 × 106 1‐1 erythrocytes in at least one of the samples. The highest erythrocyte count was 23900 × 106 1‐1 in a control patient, The 24‐hour sample was blood‐tinged (erythrocytes >1000X106 1‐1) in two patients in the arthroplasty group, in one patient in the vascular group and in four patients in the control group. In spite of the haemorrhages detected in this study, no related neurological symptoms or other serious consequences were observed. The risk of subarachnoid haemorrhage was not increased by drugs affecting coagulation.
ECG T‐wave amplitude changes during thiopentone induction with or without alfentanil
Authors: Annila P. , Lindgren L. , Loula P. , Dunkel P. , Annila I. , Yli‐Hankala A.
Published: January 2009

The T‐wave amplitude of ECG is thought to reflect the sympathetic tone of the heart but anaesthesia studies on this topic are rare. Haemodynamic and ECG T‐wave amplitude changes were studied during induction of anaesthesia in 24 ASA I‐II patients. Twelve patients were given alfentanil 30 μg kg‐1 at induction while physiologic saline was given to the rest (control). Thiopentone was then administered at the rate of 5 mg s‐1 until eyelash reflex disappeared. Vecuronium 0.1 mg kg‐1 was given thereafter. No anticholinergics were used. The lungs were ventilated with 40% oxygen in air. Haemodynamic parametres and T‐wave amplitude were measured before induction, before intubation, 30 s, 3 min and 5 min after intubation. A significandy higher amount of thiopentone was needed to abolish the eyelash reflex in the control group than in the alfentanil group (P<0.001). There were no changes in heart rate (HR) in the alfentanil group during the trial. Systolic and diastolic arterial pressures (SAP and DAP) were continuously below the preinduction levels in the alfentanil group. After baseline HR, SAP and DAP were significantly higher in the control group than in the alfentanil group at each data point. T‐wave amplitude flattened significantly (P<0.001) after intubation in the control group while no significant changes were seen in the alfentanil group. T‐wave flattening correlated to the increases in HR (P<0.01) and SAP (P<0.01). Three control patients with flattened T‐wave had a transient bigeminia period after intubation. It is concluded that ECG T‐wave amplitude flattening was associated with pressure and heart rate response to laryngoscopy and intubation. Alfentanil blunted these responses and prevented T‐wave changes after intubation.
The laryngeal mask simplifies airway management during percutaneous dilational tracheostomy
Authors: Lyons B. J. , Flynn C. G. M.
Published: January 2009

The Laryngeal Mask Airway (LMA) is used for many procedures which previously required endotracheal intubation. Percutaneous Dilational Tracheostomy (PCT) facilitates the bedside insertion of a tracheostomy tube in the Intensive Care Unit. Most patients requiring this procedure are intubated with a conventional endotracheal tube. Insertion of a LMA has advantages over tracheal intubation for PCT mainly because the artificial airway lies remote from the operating field. Three cases are reported to illustrate these advantages.
Studies on the halothane‐diethyl‐ether azeotrope
Authors: Kalman S
Published: January 2009

Abstract: Requirements for a safe standard for anaesthesia under primitive conditions differ from those under peaceful circumstances. It is important not to blunt the reflexes that guard vital functions. Safety requirements concerning breathing, circulation, and drug interaction must be sharpened because professional surveillance of the patient may be restricted. The halo‐thane‐diethyl‐ether azeotrope (HE azeotrope) has properties that could make it suitable for anaesthesia under adverse circumstances. We have re‐evaluated the HE azeotrope with special reference to safety in studies on 102 patients and 19 pigs.
Assessment of respiratory system compliance by a flow recording method
Authors: Darowski M. , Gottlieb‐Inacio I. , Ludwigs U. , Hedenstierna G.
Published: January 2009

Standard methods for the assessment of the compliance of the respiratory system require recordings of both airway pressure and ventilatory volume. A method based on the recording of respiratory flow only, with no need of measuring airway pressure was reported some years ago. The purpose of the present study was to test a modification of this flow‐recording technique.

The technique is based on the measurement of inspiratory flow with and without the addition of a source of external compliance added to the inspiratory circuit. The difference in inspiratory flow between these two situations can be used to derive the compliance of the respiratory system. The method was tested in model experiments and in patients with acute respiratory failure, and compared with a standard method based on airway pressure and inspiratory gas flow recording.

Model experiments showed strong correlation between the new flow‐recording method and the standard method (r—0.99, P <0.001) with a coefficient of variation of less than 2% with both methods. In patients with acute respiratory failure, the flow and standard methods gave similar results when no end‐inspiratory pause was applied (mean difference 5±40 ml/kPa (x±s.d.)). The standard method gave significandy higher compliance values, different from the flow method, when an end‐inspiratory pause of 10% was applied (mean difference 53 ±2 ml/kPa, P <0.01). The flow method was not influenced by the use of an end‐inspiratory pause. In conclusion, the flow method measures dynamic compliance and is not influenced by end‐inspiratory or end‐expiratory flow. It requires only a flow‐sensor for the measurement of relative values, reducing the need for calibration procedures. However, the flow method cannot replace conventional technique for assessment of static compliance.
Effects of arterial hypoxia and β‐adrenoceptor blockade on cerebral blood flow and oxygen uptake following E. coli endotoxin in dogs
Authors: Westerlind A. , Larsson L. E. , Häggendal J. , Ekström‐Jodal B.
Published: January 2009

Earlier studies in normoxia have shown that an endotoxin injection in dogs leads to an increase in cerebral metabolic rate of oxygen (CMRo2), a decrease in cerebral blood flow (CBF) and increased concentrations of monoamines in blood and cerebrospinal fluid (CSF). In animals pretreated with propranolol (PPL) the CMRo2 increase was abolished and thus β‐adrenoceptor mediated. Arterial hypoxia normally increases CBF without any influence on CMRo2. The aim of this study was to investigate the effects of moderate arterial hypoxia on CBF, CMRo2 and catecholamine concentrations in blood and CSF after endotoxin with and without pretreatment with PPL.

Three groups of dogs were studied. Group 1: Six animals were subjected to arterial hypoxia without any other intervention. Group 2: Six animals were given an endotoxin injection (E. coli lipopolysaccharide O 111: B 4), before the induction of hypoxia. Group 3: Eight animals were pretreated with PPL per os, 12.5 mg . kg‐1 twice a day for one week before the experiments, and the effects of arterial hypoxia were studied both before and after an intravenous injection of endotoxin. Two levels of hypoxia were studied; oxygen saturation in arterial blood aiming at 75 and 50%. Endotoxin was given intravenously in a dose of 1 mg . kg‐1 bodyweight over a 5 minute period.

After an endotoxin injection, the response to arterial hypoxia was an increase in CMRo2, in contrast to the unchanged CMRo2 without endotoxin. After pretreatment with PPL the increase in CMRo2 after endotoxin was prevented. The CBF reaction to hypoxia was uniformly an increase. Adrenaline and noradrenaline in blood and noradrenaline in CSF were high and similar in the different hypoxic situations. Indications of a disturbed blood‐brain barrier function were found in uptake‐release of catecholamines.

In conclusion an increase in CMRo2 and CBF was found in moderate arterial hypoxia after an endotoxin injection in dogs. The increase in CMRo2 during hypoxia was abolished when the dogs were pretreated with PPL suggesting that it is β‐adrenoceptor mediated.
Comparison of eltanolone and thiopental in anaesthesia for termination of pregnancy
Authors: Eriksson H. , Haasio J. , Korttila K.
Published: January 2009

This study was presented in part at the 22nd meeting of the Scandinavian Society of Anaesthesiologists in Kuopio, Finland, in June, 1993.

Eltanolone, a new steroid hypnotic, was compared to thiopental in short anaesthesia.

Sixty unp re medicated, ASA 1—2 women were randomized to receive eltanolone 0.6 (group El) or 0.8 mg . kg‐1(group E2) or thiopental 4 mg . kg‐1(group T) for induction of anaesthesia. One minute before induction glyco‐pyrrolate 0.2 mg and alfentanil 15 μg . kg‐1i.v. were administered. If induction failed, additional boluses of the test drug were given. Anaesthesia was maintained with 67% nitrous oxide in oxygen, and additional bolus doses of the test drug were given in a standardized fashion, if needed. Recovery was assessed by a research nurse blinded to the agent used.

Mean±s.d. induction doss were 0.7±0.1 mg . kg‐1(group E1), 0.8±0.1 mg . kg‐1(group E2) and 4.0±0.0 mg . kg‐1(group T). Induction time was prolonged in the group E1 compared to the other two groups (P<0.05). Side effects were few in all groups, but involuntary muscle movements or hypertonus occurred in 23% of the patients in the eltanolone and in 3% in the thiopental groups (n.s.). Early recovery (eye opening, orientation and sitting) was slower in both eltanolone groups compared to the thiopental group (P<0.01). No differences between the groups were found in toleration of oral fluids, walking, voiding, postoperative analgesic requirements or postoperative nausea and vomiting. Psychomotor recovery, as assessed by the Maddox Wing and the Digit Symbol Substitution tests was similar between the groups. Home readiness was achieved in 78 min (34–101 min), 90 min (29–181 min), and 84 min (36–111 min) in the groups E1, E2 and T, respectively [median (range)] (n.s.) Early recovery was faster after thiopental than eltanolone, but no differences between the groups regarding home readiness or the psychomotor tests were found.
Quantifying the interaction of vecuronium with enflurane using closed‐loop feedback control of vecuronium infusion
Authors: Olkkola K. T. , Kansanaho M.
Published: January 2009

The influence of different levels of enflurane anaesthesia on infusion requirements of vecuronium was studied in 40 adult surgical patients. Ninety percent neuromuscular block was maintained by computer controlled infusion of vecuronium. During the first 90 min study period all patients received fentanyl‐nitrous oxide‐oxygen (2:1) anaesthesia. For the following 90 min the patients were randomly assigned to receive enflurane at different end‐tidal concentrations: group I, control, fentanyl‐nitrous oxide anaesthesia; group II, enflurane 0.3%‐nitrous oxide; group III, enflurane 0.6%‐nitrous oxide; group IV, enflurane 0.9%‐nitrous oxide. Every patient served as his/her own control and the changes of vecuronium infusion requirements were determined individually. When the administration of enflurane was started, vecuronium infusion requirements decreased progressively until 90 min. In group II the infusion rate lowered from 80±28 to 56±20 μg . kg‐1 . h ‐1, in group III from 61 ±29 to 34±17 μg . kg‐1 . h‐1 and in group IV from 65±20 to 30± 14 μg . kg‐1 . h‐1. In the control group the infusion rate decreased during the three hour study period from 69± 17 (first 90 min period) to 59± 16 μg . kg‐1 . h‐1 (second 90 min period). Enflurane reduces the dose requirements of vecuronium administered by continuous infusion in a dose‐ and time‐dependent manner.
Anaesthesia for short outpatient procedures. A comparison between thiopentone and propofol in combination with fentanyl or alfentanil
Authors: Jakobsson J. , Rane K.
Published: January 2009

We studied supplementation of propofol or thiopentone anaesthesia with 0.5 or 1.0 mg alfentanil or 0.05 or 0.1 mg fentanyl for minor gynaecological outpatient procedures. Four hundred patients scheduled for elective termination of pregnancy were randomly allocated to one of eight groups. Induction agent doses, peroperative complications, complaints about pain and emesis during the postoperative period, and time to discharge were studied. Propofol compared to thiopentone was associated with a shorter time to discharge, 103±28 and 115±33 minutes respectively (P<0.05) and anxiety during recovery was more frequent in the thiopentone group (P<0.05). The need for postoperative reserve analgesics was less in the alfentanil group (P<0.05). We found, however, no major differences between the supplementations tested regarding the total dose of induction agent, emesis or time to discharge. Supplementation with 1.0 mg of alfentanil to propofol was found to be the best combination tested for short outpatient procedures.
Thoracic electrical impedance and fluid balance during aortic surgery
Authors: Jónsson F. , Madsen P. , Jørgensen L. G. , Lunding M. , Secher N. H.
Published: January 2009

Indices of fluid balance were evaluated during and after aortic surgery in 16 consecutive patients. Thoracic electrical impedance (TI), heart rate (HR), central venous (CVP), pulmonary artery mean (PAMP), pulmonary wedge (PWP) and mean arterial (MAP) pressure as well as fourteen arterial and venous blood gas variables were followed. Consistent with a reduction of TI by 4.2 (—5.2 to 9.2) Ohm (median and range) during the operation, fluid balance was in excess of 1.8 (—0.1 to 3.3) 1 when evaporation was not taken into account, and it remained elevated by 1.3 (0.0 to 5.4) 1 on the first postoperative morning. The HR, MAP and PWP remained stable, while CVP and PAMP decreased by 6 (‐2 to 13) and 6 (‐1 to 22) mmHg, respectively. Of the determined variables only TI revealed a meaningful correlation to fluid balance (rho= —0.41; P<0.01). Haemoglobin concentrations increased in proportion to the administered packed erythrocytes, while arterial oxygen saturation, pH and base excess decreased in proportion to the excess fluid. The results indicate that while central venous and pulmonary artery mean pressures gave the impression of a volume deficit, the positive fluid balance was mirrored by thoracic electrical impedance, and that even a minor increase of fluid balance may affect pulmonary function in patients subjected to aortic surgery.
Anaesthesia for microvascular surgery in children
Authors: Inberg P. , Kassila M. , Vilkki S. , Tarkkjla P. , Neuvonen P.
Published: January 2009

Now Actays, microvascular reconstructions are performed with high success rate even in small children. The combination of general anaesthesia and axillary plexus block was used in this prospective study in order to achieve optimal surgical conditions in these challenging operations. Fifteen children under eight years of age (1–8 years) were anaesthetised with a standardised anaesthesia method using a combination of general anaesthesia and axillary plexus block for microvascular toe‐to‐hand transfer. The duration of anaesthesia varied between 7.5—14.5 hours (mean 11 h). The difference in peripheral skin temperature was used to indicate the difference in peripheral circulation. Due to plexus block, the mean skin temperature in the operated hand was 1.4 d̀C higher than in the opposite extremity at the end of the operation. In the early postoperative phase the temperature difference increased to 4.8d̀C (P<0.01) due to vasoconstriction in the control hand. The mean temperature in the transplant was 33.3±2.4d̀C at the end of the operation. Primary microvascular results were good in all but two children who needed reoperations. All of the transfers survived. The mean central temperature increased progressively during the operation from 36.2d̀C to 37.6d̀C. One 1‐year‐old child developed a moderate hyper‐thermia of 39.1d̀C. According to this study axillary plexus block can be combined with general anaesthesia in prolonged microvascular operations. When the effect of general anaesthesia ceased, the plexus block effectively increased peripheral circulation in the operated hand.
Interactions between the lipophilic opioid sufentanil and clonidine in rats after spinal application
Authors: Meert T. F. , Kock M. De
Published: January 2009

Background: Alpha2‐adrenoceptor agonists, such as clonidine, can potentiate the analgesic properties of spinal opioids. In order to further extend this observation to highly lipophilic and potent spinally acting opioids, we tested the interactions between clonidine and sufentanil after both epidural and intrathecal administration in rats.

Methods: The rats were equipped with spinal catheters. Antinociceptive testing was performed with the Tail Withdrawal Reaction test. Dose‐response functions of sufentanil, clonidine and combinations of clonidine plus sufentanil were determined.

Results: These indicated that 1) sufentanil, but not clonidine alone, results in a dose‐related antinociception after both the epidural and the intrathecal route of administration; 2) In combination with normally inactive doses of sufentanil, the addition of clonidine results in activity; 3) In a particular dose‐range of sufentanil, there is a direct relationship between the doses of sufentanil and clonidine needed to produce antinociception; 4) Even at very high doses of clonidine, a minimal amount of sufentanil is needed to produce antinociception and 5) At the conditions tested here, the contribution of clonidine is minimal at high, intrinsic active doses of sufentanil.
The space blanket and shivering during extradural analgesia in labour
Authors: Buggy D. , Gardiner J.
Published: January 2009

The incidence of shivering in women during epidural analgesia in labour is up to 33%, and may be highly distressing. Its mechanism is unclear, but the most widely held theory is that it is thermogenic. Pharmacological suppression may adversely effect the foetus or induce maternal hypothermia, and although physical remedies such as direct heat application are effective, they are also expensive and cumbersome. We recently found that the space blanket, a simple aluminised metallic foil, used pre‐emptively, reduces shivering after general anaesthesia. We investigated the effect of the space blanket on the incidence and intensity of shivering, axilliary skin temperature, and subjective perception of cold during epidural analgesia for labour in 50 women over a four‐hour time frame. Patients were randomised into group 1, who were wrapped in a space blanket immediately after commencement of epidural analgesia with bupivacaine, and group 2 (matched controls). Shivering was defined as visible tremor of the head, neck, trunk or limbs as observed by the attending midwives. Twenty‐nine percent of group 1 and 35% of group 2 shivered (not significant), but a reduction in shivering intensity was observed in group 1 (P<0.05). There was no significant difference in skin temperatures in either group, and no significant temperature change within the groups. Both groups had similar thermal comfort scores throughout the study, which correlated poorly with the presence of shivering. We conclude that there is no benefit in application of the space blanket to reduce epidural‐analgesia related shivering in labour, which may indicate a non‐thermogenic mechanism for this phenomenon.
The metabolic effects of oral tizanidine in healthy volunteers
Authors: Taittonen M. , Räty H. , Kirvelä O. , Aantaa R. , Kanto J.
Published: January 2009

This pilot study compared the metabolic effects of placebo and 6 mg and 12 mg of oral tizanidine in random double‐blind cross‐over fashion in five healthy volunteers.

The metabolic measurements were made with a portable metabolic chart (Deltatrac, Datex/Instrumentarium, Helsinki, Finland). Heart rate (HR), systolic (BPS), mean (BPM) and diastolic (BPD) blood pressure were measured noninvasively. Subjective assessment of tiredness and dryness of mouth were measured by using visual analogue scales (VAS).

There were no statistically significant differences in tiredness or dryness of mouth between the groups. BPD decreased significantly after both doses of tizanidine when compared to placebo (by an average of 12% after 6 mg of tizanidine and 15% after 12 mg of tizanidine from the baseline). Oxygen consumption and energy expenditure decreased significantly after 6 and 12 mg of tizanidine when compared to placebo. The average decrease in oxygen consumption was 3% after 6 mg of tizanidine and 8% after 12 mg of tizanidine, when compared to the baseline. Energy expenditure decreased by an average of 5% after 6 mg of tizanidine and 9% after 12 mg of tizanidine, when compared to the baseline. There were no other statistically significant differences between the groups.

This study indicates that 6 and 12 mg of oral tizanidine can be useful for reducing energy expenditure and oxygen comsumption without prominent cardiovascular effects.