bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of motor blockade by isometric force measurement and electromyographic recording during epidural anaesthesia – a methodological study
Authors: Nydahl P. A. , Axelsson K. , Hallgren S. , Larsson P. G. , Leissner P. , Philipson L.
Published: January 2009

Methods for assessing motor blockade by means of isometric force measurements and surface electromyographic (EMG) recordings in the lower extremities and abdominal wall were evaluated in 30 volunteers. The coefficients of variation were 10% for force measurements and 14% and 20% for average rectified EMG (RIEMG) recordings over the quadriceps muscle and abdominal muscles, respectively, and 8% overall for TURNS (the number of changes in the sign of the direction of the EMG signal). Seven of the 30 volunteers received epidural anaesthesia with 20 ml of mepivacaine 2% with adrenaline. The mean maximal cephalad analgesic level was T9. At that abdominal segment, RIEMG showed a reduction of 50% and TURNS of 20%. Isometric force and RIEMG recorded simultaneously in the quadriceps muscles during epidural anaesthesia displayed a linear relationship with a correlation coefficient of 0.91. TURNS was insensitive to force variations above 60% of maximum voluntary contraction. During the regression phase, 90% of both the initial force and RIEMG value was noted 180 min after the epidural injection. It is concluded that recording of RIEMG is a good method for quantitative assessment of motor blockade during epidural anaesthesia.
Comparison of rectal to intramuscular administration of midazolam and atropine for premedication of children
Authors: DE Jong P. C. , Verburg M. P.
Published: January 2009

The effectiveness of midazolam and atropine as anaesthetic premedication was investigated, comparing rectal to intramuscular administration. A total of 202 children varying in age from 10 months to 9 years, who had been admitted to the Day Surgery Department for short ENT procedures, were assigned to one of two groups on a random basis. The first group (n = 102) was given 0.5 mg/kg midazolam and 0.05 mg/kg atropine as a rectal solution 30 to 75 min prior to induction, while the second group (n = 100) was given 0.15 mg/kg midazolam and 0.02 mg/kg atropine as an intramuscular injection 20 to 60 min prior to induction. The levels of sedation and salivation were compared, as was the degree of tolerance to intravenous induction. The parents of children older than 3 years of age were given a questionnaire designed to determine the degree of amnesia. We found this combination of drugs to be effective in the relief of anxiety, the inhibition of salivary secretion and the promotion of memory loss, regardless of the route of administration. We feel that rectal administration is preferable because it is not associated with pain or anxiety.
Buprenorphine antagonism of ventilatory depression following fentanyl anaesthesia
Authors: Boysen K. , Hertel S. , Jørgensen B. Chræmmer , Risbo A. , Poulsen N. J.
Published: January 2009

In order to compare the effect of buprenorphine and naloxone on respiratory depression after fentanyl anaesthesia (25 μg/kg), 32 women scheduled for elective abdominal hysterectomy participated in a doubleblind randomized investigation. At termination of anaesthesia, after antagonizing residual neuromuscular blockade, 20 normocapnic patients with a respiratory rate of 4 breaths/min or less entered the study, receiving either buprenorphine (0.6 mg in 20 ml NaCl) or naloxone (0.4 mg in 20 ml NaCl) 2 ml/min until 20 ml was given or until the respiratory rate exceeded 8 breaths/min. Respiratory rate, Pacc>2, sedation score, and pain intensity were evaluated during a 3–h study period. Fifteen min after beginning the treatment, all the patients in both groups had their ventilatory depression antagonized. There were no statistically significant differences in respiratory rates between groups except at 15 min. On no occasion did either Paco2 or a sedation score differ statistically significantly between the groups. At 15 min all patients in the buprenorphine group had no or mild pain, compared to the patients in the naloxone group, of whom 50% had moderate to severe pain (P < 0.05). It seems as if bupenorphine is as effective as naloxone in antagonizing respiratory rate depression following fentanyl anaesthesia.
Serum amino acid patterns and toxicity symptoms following the absorption of irrigant containing glycine in transurethral prostatic surgery
Authors: Hahn R. G.
Published: January 2009

The relationships between the scrum concentrations of amino acids, the volume of irrigating fluid absorbed and symptoms of glycine toxicity were analysed in 18 patients who had undergone transurethral resection of the prostate and in whom intravascular absorption of irrigating fluid containing 2.2% glycine had been recorded. A mean of 7% of the transferred glycine could be detected in the serum within 10 min of irrigant absorption. The half–life of glycine in serum was twice as long when the volume of irrigant absorbed exceeded 1500 ml (100 min; n = 6), and the serum levels of alanine, aminobutyrate, proline and serine were significantly more elevated, than when the volume of irrigant absorbed was between 900 and 1300 ml (n = 6). Where the amount of glycine transferred exceeded 0.5 g kg‐1, symptoms of glycine toxicity developed, their onset coinciding with a rapid increase in the serum levels of non–essential amino acids other than glycine.
The reduction of pain on injection of propofol: the effect of addition of lignocaine
Authors: Hansen S. Helbo , Westergaard V. , Krogh B. L. , Svendsen H. P.
Published: January 2009

The effects of addition of 1 ml of lignocaine (10 mg) or isotonic saline to 19 ml of the emulsified preparation of propofol (Diprivan®) were studied in a randomised, double–blind trial in 80 patients. The incidence and severity of pain on injection of propofol were significantly reduced by the addition of lignocaine (P < 0.01).
The anaesthetic management of an infant with frontometaphyseal dysplasia (Gorlin–Cohen syndrome)
Authors: Mehta Y. , Schou H.
Published: January 2009

We describe an infant with frontometaphyseal dysplasia, who presented to us twice for anaesthesia for orthopaedic surgery. These patients have facial asymmetry, mandibular hypoplasia, bradycardia, restrictive lung disease, primary pulmonary hypertension, skeletal abnormalities and difficult endotracheal intubation. The patient also showed laryngeal stridor because of laryngomalacia, vocal cord paralysis and subglottic stenosis. Light premedication along with atropine, ECG and blood pressure monitoring, gradual inhalational induction and intubation of the spontaneously breathing patient, careful positioning and postoperative CPAP are recommended.
Comparison of ketamine and pentobarbital anesthesia with the conscious state in a porcine model ofPseudomonas aeruginosasepticemia
Authors: Worek F. S. , Blümel G. , Zeravik J. , Zimmermann G. J. , Pfeiffer U. J.
Published: January 2009

LivePseudomonas aeruginosa(2.5·109·kg‐1·h‐1) were administered to awake (Group A, n = 10) and anesthetized piglets, which were given intravenous ketamine (Group K, 10 mg·kg‐1·h‐1, n = 8) or pentobarbital (Group P, 15 mg·kg‐1h‐1, n = 8). The anesthetized animals were mechanically ventilated. In addition, a pentobarbital group (Group CP, n = 6) and a ketamine control group (Group CK, n = 6) were studied. The mean survival time was 10.5 ± 3.0 h in Group A, 10.6 ± 2.8 h in Group K, and 1.8 ± 1.3 h in Group P. In Group P the arterial pressure, the cardiac output and the systemic vascular resistance declined soon after start of the bacterial infusion, whereas the pulmonary artery pressure increased. The animals died of irreversible circulatory failure. In Group K pronounced pulmonary hypertension and lethal pulmonary edema developed. There was no circulatory failure in Group A, but the animals also died of marked pulmonary edema. Groups CP and CK exhibited stable hemodynamics for a period of 8 h. The results of this study suggest a deleterious effect of pentobarbital on hemodynamics and survival time, and a minor suppressive action of ketamine on the circulation in septicemia. Therefore, data obtained from septic shock studies applying pentobarbital have to be evaluated carefully. Investigation of the effects of gram‐negative bacteria or endotoxin should be performed in unanesthetized or, if anesthesia is necessary, in ketamine‐anesthetized animals.
Alterations in the pharmacokinetic properties of amide local anaesthetics following local anaesthetic induced convulsions
Authors: Arthur G. R. , Feldman H. S. , Covino B. G.
Published: January 2009

The comparative pharmacokinetic properties of lidocaine, bupivacaine, etidocaine and mepivacaine were investigated in convulsing and non‐convulsing dogs. The same dose of a given local anaesthetic was administered as either a 30‐s intravenous (IV) bolus to produce convulsions or as a 15‐min IV infusion producing no convulsions. Derived pharmacokinetic data were found to be different in convulsing and nonconvulsing animals. Total body clearance was found to be significantly reduced for lidocaine (29%,P<0.05), bupivacaine (31%,P<0.05), etidocaine (60%,P<0.01) and mepivacaine (68%,P<0.01) in convulsing animals. Increases in elimination half‐life only achieved statistical significance in mepivacaine‐treated animals (non‐convulsing 45.2 min, convulsing 105.4 min,P<0.01). Overall, the most profound effects of convulsions on pharmacokinetic data were seen with mepivacaine. Convulsions were associated with increases in heart rate ranging from 117% (lidocaine,P<0.05) to 129% (mepivacaine,P<0.05), increases in cardiac output ranging from 78% (mepivacaine) to 232% (bupivacaine,P<0.05) and increases in mean arterial pressure ranging from 45% (lidocaine,P<0.05) to 80% (bupivacaine,P<0.05). The results suggest that when local anaesthetic‐induced seizures occur in man, it cannot be assumed that these drugs will be distributed and eliminated as predicted by intravenous infusion of non‐toxic doses.
Suppression of the pressor effect of centrally administered thyrotropin‐releasing hormone under halothane, pentobarbital and flunitrazepam anaesthesia
Authors: Tanaka H. , Okuda C. , Sawa T. , Mizobe T. , Demura H. , Miyazaki M.
Published: January 2009

Intracerebroventricular (i.c.v.) administration of thyrotropin‐releasing hormone (TRH) caused an increase in blood pressure (BP) and heart rate (HR) in conscious rats. The pressor effect was greatly diminished by adrenalectomy as well as after pretreatment with phentolamine, an α‐receptor antagonist or with mecamylamine, a ganglion blocker, suggesting that centrally administered TRH increases BP mainly by stimulating sympathetic activity. Under halothane (0.8%), pentobarbital (33 mg/kg, i.p.) and flunitrazepam (0.8 mg/kg, i.v.) anaesthesia, the pressor effect of TRH was almost completely blocked. The increase in BP induced by peripheral α‐receptor stimulation with phenylephrine was not affected by the anaesthetics at these doses. Pretreatment with atropine (50 μg, i.c.v.) significantly reduced the pressor effect of TRH. Intracerebroventricularly administered haloperidol and bicuculline also partially diminished the increase in BP produced by TRH, while other neurotransmitter blockers such as phentolamine, propranolol and naloxone did not. These results indicate that the anaesthetics at the doses employed interfere with the central neuronal pathway(s), probably cholinergic pathways, through which TRH exerts its pressor effect.
Lower limb compression using inflatable splints to prevent hypotension during spinal anaesthesia for caeserean section
Authors: Goudie T. A. , Winter A. W. , Ferguson D. J. M.
Published: January 2009

The efficacy of pneumatic compression of the lower limbs using inflatable leg splints in prevention of hypotension during spinal anaesthesia was assessed in an open study of 46 patients undergoing elective caesarean section. All patients received 15 ml/kg of Hartmann's solution before spinal anaesthesia and were tilted to the left to minimise aortocaval compression. Splints were rapidly inflated to a pressure of 5.3 kPa immediately after institution of the block in treated patients. Blood pressure was measured by a cuff method at 1‐min intervals until the commencement of surgery. Hypotension was less common (P<0.05) and less severe (P<0.05) in splint‐treated patients, but the incidence was unacceptably high in both treated (48%) and control (83%) groups.
Particulate contamination in spinal analgesia
Authors: Eriksen S.
Published: January 2009

A microscopic investigation was undertaken to quantify the amount of particulate contamination in the injectates of bupivacaine 0.5% in spinal analgesia. No differences were found between samples prepared with either a glass syringe or a disposable plastic syringe, nor could differences be documented between groups where atraumatic opening of vials, perforation of vial stoppers or opening of glass ampoules was performed. The use of commercially available bacterial filters was followed by a significant increase in the amount of particulate contamination, probably filter debris. The clinical use of such filters in spinal analgesia is therefore questionable.
Cardiovascular responses caused by the combination of lidocaine and vecuronium in the induction of general anaesthesia
Authors: Pouttu J. , Tuominen M. K. , Rosenberg P. H.
Published: January 2009

Fentanyl, vecuronium and enflurane may cause bradyarrhythmias during anaesthesia. Lidocaine administered before endotracheal intubation may interact synergistically with these agents. In this randomized and double‐blind study, lidocaine 1 mgkg‐1 (24 patients) or saline (20 patients) was given, immediately after glycopyrrolate 5 μgkg‐1, fentanyl 1.5 μgml‐1 and thiopentone 3–5 mgkg‐1, together with vecuronium 0.1 mgkg‐1 as a rapid i.v. injection to healthy (ASA 1) surgical patients. Enflurane 0.8% was included in the inhaled gases 10 min and enflurane 1.6% 25 min after lidocaine administration. The plasma concentrations of lidocaine rose to a mean level of 3.1 μgml‐1 (maximum 7.1 μgml‐1) which may affect the electrical conduction at various sites in the heart. There were no statistically significant differences in arterial blood pressures or heart rates during anaesthesia between the groups. The incidence of junctional rhythm was 7/24 patients in the lidocaine group and 5/20 patients in the saline group. Three patients in the lidocaine group, and two patients in the control group developed junctional rhythm immediately after intubation. The plasma concentrations of vecuronium were unaffected by lidocaine. The ratio of the unbound lidocaine to plasma protein bound lidocaine was at the expected level and did not differ significantly 2 and 10 min after the injection.
Vasopressor therapy for hypotension due to epidural anesthesia for cesarean section
Authors: Ramanathan S. , Grant G. J.
Published: January 2009

Maternal hemodynamic changes and neonatal acid‐base status were assessed in 127 healthy patients undergoing elective cesarean section under epidural anesthesia. An impedance cardiograph was used to measure stroke volume (SV), ejection fraction (EF) and end‐diastolic volume (EDV). In addition, neonatal umbilical venous and arterial Po2, Pco2, pH, base excess, lactate, pyruvate, excess lactate, and L/P ratio were measured at birth. Patients were divided into three groups. Group 1 (n = 53) required no vasopressor (normotensive controls). In Group 2 (n = 37), mean blood pressure (BP) decreased from 90 mmHg to 67 mmHg (12.0 to 8.9 kPa), and ephedrine was given in 5‐mg increments to maintain systolic BP>100 mmHg (13.3 kPa). In Group 3 (n = 37), BP decreased from 83 mmHg to 62 mmHg (11.1 to 8.2 kPa), and phenylephrine was administered in 100 μg increments to maintain systolic BP>100 mmHg (13.3 kPa). In Groups 2 and 3 the SV and EDV decreased 43% and 33% respectively when hypotension developed. Both vasopressors restored BP, SV and EDV to near baseline values. Neonatal Apgar scores and acid‐base profiles were not signficantly different among the three groups of neonates, nor were they different between the two hypotensive groups. It is concluded that: 1) transient maternal hypotension does not affect neonatal acid‐base status; 2) both ephedrine and phenylephrine increase cardiac preload; and 3) an α agent like phenylephrine does not cause fetal acidosis when used for treating maternal hypotension.
The effect of bupivacaine paracervical block on the neurobehavioural responses of newborn infants
Authors: Kangas‐Saarela T. , Jouppila R. , Puolakka J. , Jouppila P. , Hollmén A. , Puukka M.
Published: January 2009

The effects of maternal bupivacaine paracervical block on neonatal neurobehavioural responses were studied at the ages of 3 h, 1 day, 2 days and 4–5 days. Subjects were healthy, term neonates born vaginally to 10 mothers with paracervical block and to 12 mothers without analgesia. No statistically significant differences were found in the responses between the groups. It is concluded that paracervical block with a small dose of bupivacaine, applied by experienced obstetricians to non‐risk parturients with healthy foetuses, has no detrimental effects on newborn behaviour or neurological recovery.
Assessment of the efficiency of pulmonary oxygenation. The choice of oxygenation index
Authors: Zetterström H.
Published: January 2009

Oxygen‐derived indices are often used as alternatives to determination of venous admixture (Qva/Qt) when a pulmonary arterial catheter is not in use, but the question of which more accurately indicates the efficiency of oxygenation is controversial. The theoretical relationships between six measures of oxygenation (Pao2, Sao2, P(A‐a)o2, Pao2/Fio2, P(A‐a)o2/Pao2, Pao2/Pao2) and venous admixture were analyzed with special reference to the influence of the concentration of inspired oxygen (Fio2). In addition, the predictability of Qva/Qt was evaluated on the basis of 100 authentic sets of arterial and mixed venous blood gas data. Of the above six indices, Pao2/Fio2 was most accurate (r = 0.88), but was far from independent of the Fio2 used. However, a direct Estimate of Venous Admixture (EVA) — based on arterial blood analysis and with C(a‐v)o2 assigned a value of 50 ml·l‐1 — predicted Qva/Qt still better (r = 0.95). It is concluded that when mixed venous blood gas data are lacking, EVA is the preferable measure of oxygenation.
The influence of position on ventilation‐perfusion distribution after abdominal surgery
Authors: Bonnet F. , Bourgain J. L. , Matamis D. , Tesseire B. , Viars P.
Published: January 2009

The effects of a change in position on gas exchange and ventilation perfusion (VA/Q) distribution were studied in 12 patients, after abdominal surgery. VA/Q distribution was determined from retention and excretion curves of six inert gases of different solubilities, in supine and sitting patients, during spontaneous breathing. Changing position from supine to sitting resulted in an increase in minute ventilation and a decrease in Paco2 without any change in Pao2. With regard to VA/Q distribution, an estimated shunt of 5.2% ± 3.4 was documented in all the patients in the supine position, and was associated with a large percentage of low VA/Q, regions (20.0% ± 13.0) in six of them. Patients with associated estimated shunt and low VA/Q regions were those with the greatest amount of venous admixture (respectively: 27.3% ± 7.2, and 14.9% ± 3.0, for patients without low VA/Q regions, P<0.01). When patients were placed in the sitting position, the estimated shunt was not reduced, but the percentage of low VA/Q, regions decreased when it was documented. Despite the improvement of VA/Q distribution in the sitting position, the lack of significant change in Pao2 may be explained by the simultaneous decrease in Pvo2 caused by a decrease in cardiac output.
Comparison of propofol induction with thiopentone or methohexitone in short outpatient general anaesthesia
Authors: RÆder J. C. , MisvÆr G.
Published: January 2009

The per‐ and post‐operative characteristics of three different i.v. anaesthetic induction agents were studied double‐blindly in 75 patients admitted for outpatient gynaecological dilatation and curettage. All the patients were premedicated with midazolam 0.1 mg/kg i.m. Induction started with alfentanil 0.015 mg/kg i.v. 60 s before either: propofol 2.2 mg/kg i.v., or thiopentone 4.0 mg/kg i.v., or methohexitone 2.0 mg/kg i.v. All the patients received 66% nitrous oxide in oxygen. The propofol patients were significantly better relaxed and had a higher incidence of hypotension during the procedure. The methohexitone patients had higher pulse rates and a higher frequency of hiccups during the procedure. Propofol induction resulted in a faster awakening of the patients and a better recovery function compared with methohexitone for the first 15 min and compared with thiopentone for the first 240 min after the procedure. Postoperative side‐effects were less frequent in the thiopentone group, and minor abdominal pain was significantly more frequent in the propofol group. There was no significant difference between the groups for any variable after 240 min postoperatively.
Influence of age on the dose‐response relationship of atracurium in paediatric patients
Authors: Meretoja O. A. , Wirtavuori K.
Published: January 2009

To assess the influence of age on the dose‐response relationship of atracurium in paediatric patients during thiopental‐fentanyl‐N2O‐O2‐anaesthesia, we studied 85 patients from neonates to adolescents. Each patient was given two doses of atracurium: following the maximum EMG response to the first dose of 150 μg/kg, an individual second dose was given, to produce exactly 95% neuromuscular block. The onset time of atracurium (time from administration to maximum effect) was shortest in neonates (2.6 min) and infants (3.3 min) and longest in adolescents (5.5 min) (P<0.01). The dose‐response curves were parallel in all patients aged 3 months or older. The ED95of atracurium was comparable for neonates and infants (226 μg/kg). This was 28% less than the ED95for patients aged 1 year or older (316 μg/kg) (P<0.01). The results explain the slightly longer‐lasting neuromuscular block in infants as compared to children following a constant atracurium dose in μg/kg. The great individual variability of the neuromuscular response, however, indicates that neuromuscular monitoring is essential in paediatric patients.
Experience with vecuroniurn during long‐lasting surgery
Authors: Eriksson L. I. , Staun P. , Cederholm I. , Lennmarken C. , Löfström J. B.
Published: January 2009

Our knowledge of the possible cumulative properties of vecuronium is limited. Previous studies have shown a tendency towards an increased duration of effect, a slightly prolonged recovery time, as well as an increased variation in duration of effect. We have studied 15 patients scheduled for middle‐ear surgery. During i.v. N2O‐O2 anaesthesia the twitch response of the adductor pollicis muscle was recorded after supramaximal stimulation of the ulnar nerve at the wrist. Prior to tracheal intubation a bolus dose of vecuronium was given (0.08 mg/kg body weight). During surgery supplementary doses of 0.02 mg/kg body weight were given at a train‐of‐four (TOF) ratio of 0.25. The duration of effect (DUR‐IT‐25) and recovery time from a TOF ratio of 0.10 to 0.25 (Recovery‐IT‐10–25) were recorded. When comparing 10 iteration doses, the mean DUR‐IT‐25 in the 15 patients studied showed only minor variations (n.s.). Each patient had a near constant interval between the iteration doses; however, a noteworthy variation between individuals was found. Recovery‐IT‐10–25 was 250 ± 80 (mean · s.d.) 240 ± 80 and 260 ± 80 s comparing the second, sixth and tenth iteration doses, respectively. In conclusion, the duration of effect vaned considerably between patients. Each patient showed, however, a near constant iteration interval and a recovery time with only small variations. This indicates that cumulation is unlikely to exist following repetitive administration of vecuronium of 0.02 mg/kg body weight.
Midazolam combined with paracervical blockade compared to general anaesthesia for curettage of the uterus
Authors: Nielsen H. Kirkegaard , Klünder K. , Møller J. T. , Werner M. U.
Published: January 2009

Two anaesthetic techniques were compared in a randomized trial of 60 ASA I and II women admitted for diagnostic dilatation and curettage of the uterus. Group I had fentanyl 2.5 μg/kg and thiopentone 2 mg/kg i.v. Supplementary thiopentone 50 mg was given every 15 s until loss of the eyelid reflex. Anaesthesia was maintained with nitrous oxide in oxygen 2/1 together with supplementary thiopentone 50 mg as required. Group II had midazolam 0.1 mg/kg i.v. and a supplementary 0.025 mg/kg every second min until sleep or dysarthria, followed by paracervical blockade with 1% mepivacaine 10 ml on each side of the portio. There was no significant depression of the cardiovascular system. The working conditions for the gynaecologist were good in both groups. The midazolam technique gave just as good amnesia as did general anaesthesia, and there was a high degree of patient satisfaction in both groups. In the thiopentone group there was a significant depression of the respiratory rate and a significantly higher frequency of adverse effects (nausea and vomiting) as compared to the midazolam group. It is concluded that paracervical blockade combined with midazolam, titrated i.v., until sleep or dysarthria, is a recommendable anaesthetic technique for diagnostic dilatation and curettage.
Inactivation of exogenous surfactant in experimental respiratory failure induced by hyperoxia
Authors: Ennema J. J. , Kobayashi T. , Robertson B. , Curstedt T.
Published: January 2009

Adult guinea pigs were exposed to 100% oxygen until, after 54–85 h, they developed severe respiratory insufficiency. One subgroup of animals was ventilated artificially with 100% oxygen for an additional 60–960 min. When the PaO2 was < 15 kPa or the PacO2 > 20 kPa, 1 ml of porcine surfactant (phospholipid concentration 80 mg.ml‐1) was instilled via the trachea. These animals were ventilated for one more hour and then sacrificed. Surfactant instillation did not improve the blood gases, nor the pulmonary pressure‐volume characteristics. All hyperoxia‐exposed guinea pigs showed prominent histologic lung lesions, including intraalveolar edema and desquamation of airway epithelium. Compared to normal guinea pigs the volume density of intraalveolar “gas” was decreased and that of intraalveolar fluid increased. The alveolar expansion pattern in histologic sections was not improved in the surfactant‐treated animals, compared to hyperoxia‐exposed guinea pigs studied immediately after death. In hyperoxia‐exposed animals, about 1.5 ml of edema fluid was sampled from the airways. Evaluated with pulsating bubble, our surfactant preparation had a minimum surface tension (γmin) close to zero. However, the γmin values of edema fluid from surfactant‐treated and nontreated guinea pigs were both about 20 mN.m‐1. The edema fluid thus seemed to inhibit the essential physical properties of exogenous surfactant. This, together with the prominent lung lesions, may explain the failure of surfactant replacement therapy at a late stage of hyperoxia‐induced respiratory failure.
Calcium, magnesium and phosphate during and after hypothermic cardiopulmonary bypass without temperature correction of acid base status
Authors: Kancir C. B. , Madsen T. , Petersen P. H. , Stokke D.
Published: January 2009

The plasma concentration variations of calcium, magnesium and phosphate were studied in ten patients during and after hypothermic cardiopulmonary bypass (CPB) without temperature correction of acid base status. During the study, pH remained stable, but all the other studied components varied significantly (P<0.001). At the start of CPB, the mean ionized calcium concentration increased 25%, and magnesium and phosphate decreased 29% and 40%, respectively, from their control values. At the end of blood cooling, ionized calcium was still 11% above its initial value, magnesium 50% above, and phosphate 39% below. Before weaning from CPB, ionized calcium remained 10% above its initial level, magnesium 41% above, and phosphate 26% below. After CPB, the different divalent ions returned to their initial levels within 1 h for ionized calcium, 6 h for phosphate and 9 h for magnesium. One day post‐CPB, ionized calcium was at its start level, magnesium 13% lower, and phosphate 36% higher. During cardiac surgery, the acid base regulation without temperature correction (so‐called “alpha stat mode”) avoided the appearance of carbon dioxide acidosis. There were widespread disturbances of the divalent ions concentrations, due principally to the different fluids used during CPB, pump priming fluids and cardioplegic solution.
Continuous measurement of pulmonary gas exchange during general anaesthesia in man
Authors: Viale J. P. , Annat G. , Bertrand O. , Thouverez B. , Hoen J. P. , Motin J.
Published: January 2009

We report a system for the continuous measurement of oxygen uptake (Vo2) and carbon dioxide output (Vco2) during open‐circuit anaesthesia. Gas concentrations were measured by a mass‐spectrometer, and expired flow by a pneumotachograph. The values measured by the system were compared in vitro to values produced by a nitrogen‐dilution technique. Excellent correlations were found. Continuous measurements were performed in 21 patients anaesthetized for abdominal surgery. Compared to pure intravenous anaesthesia (flunitrazepam‐fentanyl), anaesthesia including the administration of nitrous oxide or nitrous oxide and halothane led to more pronounced and sustained decreases in Vo2 and core temperature, with a better cardiovascular stability. Two hours postoperatively, Vo2 was not different from preoperative values. After a transient increase at the onset of anaesthesia, the respiratory exchange ratio (Vco2/Vo2) returned to preoperative values, and then remained subsequently unchanged. Based on these observations, the system described provides an accurate approach to noninvasively monitoring the pulmonary gas exchange in the operating room.
Laryngospasm‐induced pulmonary oedema
Authors: Andersen C. , Kancir C. B. , Nielsen K. D.
Published: January 2009

A case of pulmonary oedema following laryngospasm in a healthy young woman is reported. Laryngospasm occurred following surgery and was treated with positive pressure oxygen ventilation by mask and by deepening of the level of anaesthesia. The rest of anaesthesia was uneventful. During the following hour, spontaneous respiration deteriorated progressively and ended in manifest pulmonary oedema which was treated by endotracheal intubation and mechanical ventilation with PEEP for some hours.
Anxiety, pain and sedation: some psychiatric aspects
Authors: Mindusm P.
Published: January 2009

Whereas pain is an important factor that brings the patient to the dental office, fear and anxiety about pain are common reasons for patients to delay or avoid dental care. The relation between anxiety and pain is discussed in view of recent neuroanatomical and pharmacological findings obtained through modern research techniques, including positron emission tomography. Mechanisms behind sedation induced by the benzodiazepines and through psychological management of the apprehensive patient are discussed. It is concluded that the optimal quality of treatment may be obtained through the combined use of pharmacological and psychological treatment modalities
The Benzodiazepines: A pharmacological overview
Authors: Oreland Lars
Published: January 2009

Benzodiazepines exert their effects by facilitating neurotransmission in GABAergic synapses, probably by increasing the affinity of the GABA receptor to GABA. Stimulation of GABA receptors (at least of the A type) opens chloride ion channels which inhibits the ability of the cell (e.g. monoaminergic or cholinergic) to conduct nerve impulses. The endogenous ligand for the benzodiazepine receptor is probably a peptide, which is able to induce “anxiety” in rats. Thus, if the benzodiazepines are receptor agonists, the endogenous ligand would be an antagonist.

The clinical effects resulting from the above mechanism of action (anticonvulsant, muscle relaxant, anxiolytic, sedative‐hypnotic and amnesic) are discussed with special attention to preoperative sedation in dental practice.
Risk evaluation and patient assessment in sedation
Authors: Löfström Bertil
Published: January 2009

Risk assessment gives a good clinical guide to the understanding of our patients' medical problems. The dentist can cope with problems related to patients belonging to risks group 1 and 2, but not to groups 3 or 4. The results of studies on risks, morbidity, and mortality in anaesthesia teach us that the human factor and technical error provoke complications, morbidity and mortality, seemingly unnecessarily. Case history and a simple physical examination, primarily concentrated on respiration and circulation, are of greatest importance. Main risks during conscious sedation are regurgitation and aspiration of fluid and smaller objects, such as a broken dentist's drill or a cardiac complication. Most feared is the risk of of a reinfarcation. The aim of sedation is to reduce anxiety and restlessness. Of greatest importance is thorough patient information and a good doctor–patient contact.
Sedation as an alternative to general anaesthesia
Authors: Lundgren Stefan
Published: January 2009

Dental patients are generally in good health, the procedures are often short, and it is fear and anxiety about pain rather than the nature of the procedure that dictates the use of sedation or general anaesthesia. Indications and contra‐indications for sedation, appropriate agents and techniques, and facilities and personnel needed for managing and monitoring patients are discussed. Safe and effective use of sedation in combination with local anaesthesia is a realistic alternative to general anaesthesia for many outpatient procedures.
Sedation by the use of inhalation agents in dental care
Authors: Hallonsten Anna‐Lena
Published: January 2009

Nitrous oxide/oxygen has long been the mixture of gases used in dental practice to produce light sedation. The main indication for use of nitrous oxide/oxygen sedation is fear‐anxiety. The equipment used is a continuos flow machine with a fail safe system set at a minimum of 30 or 40 per cent oxygen. A standardized sedation technique starting with administration of 100 per cent oxygen, is recommended. The concentration of nitrous oxide is then slowly increased and individually set, mostly between 30 and 50 per cent. In most cases the analgesia produced by nitrous oxide is not sufficient to ensure pain‐free dental treatment. The sedation must therefore be supplemented by local anaesthesia. Side effects, e.g. restlessness, vomiting, and nausea are infrequent. About 90 per cent patients, who have difficulty in co‐operating during dental treatment, mainly because of anxiety, show excellent or fair co‐operation during nitrous oxide/oxygen sedation. Occupational exposure to nitrous oxide can be minimized by the use of scavenging systems, local exhaust systems, careful sedation technique, and equipment management.
Immunologic transfusion reactions
Authors: Högman Claes F.
Published: January 2009

ABO blood group incompatibility is of major concern because the antibodies frequently cause intravascular destruction leading to the most clinically severe complications.

Irregular erythrocyte antibodies seldom cause intravascular destruction. However, when the antibodies bind complement and are present in high concentration the extravascular destruction occurs predominantly in the liver and may cause a clinically severe reaction with hemoglobinemia, shock and DIC. Those IgG class antibodies which do not bind complement cause a spleen‐mediated, more or less drastically shortened life span of the red cells with unpleasant but usually not life threatening consequences for the patient. The transfusion reaction may occur with a delay of several days.

Compatibility testing may consist of either a cross‐match performed in such a way that both ABO incompatibility and irregular antibodies are detected, or a type‐and‐screen procedure. In the latter a computerized delivery control checking the patient's previous serological history and the donor/recipient compatibility is a recent improvement and rationalization.

In an acute situation a reduction of the normal security measures may be necessary. The clinician responsible for the patient must know the time needed for carrying out an acute blood group determination and compatibility test in the hospital and must give instructions about what normal security measures that should be refrained from.

Blood group incompatible transfusions have nowadays a much better prognosis than earlier, provided a rapid diagnosis can be made and appropriate treatment can be started promptly.

Formation of antibodies against leukocyte/thrombocyte antigens is a frequent consequence of transfusion which, however, can be prevented by modern blood component therapy. Such antibodies are a frequent cause of refractoriness to platelet transfusions in bone marrow aplasia patients.

Plasma may cause transfusion reactions in two ways: (1) by transfer of plasma proteins which react with antibodies in the recipient, (2) by transfer of antibodies which react with cellular elements or plasma proteins in the recipient. Clinically mild reactions with urticaria and a failing plasma volume expansion are common, severe reactions with anaphylactoid shock, pulmonary complications and cellular destruction are rare.
Transfusion transmitted non‐A, non‐B hepatitis
Authors: Iwarson Sten
Published: January 2009

Non‐A, non‐B of hepatitis (NANBH) may occur following blood transfusions or administration of blood products. The causative agent(s) is still not identified and the symptoms are usually mild. The only indication of infection may be increased serum alanine transferase levels. The incidence of posttransfusion NANBH has been reported as high as 4–12% in the US (average 7%) while in Sweden it is according to recent studies on the average 2%. An estimated 2–3% of Swedish blood donors are probably carriers of the NANBH agent(s). Of patients acquiring posttransfusion NANBH, 40–60% will develop chronic hepatitis which in 15–20% will progrediate to cirrhosis.
Transfusion transmitted infectious agents, excluding hepatitis and human immunodeficiency viruses
Authors: Leikola Juhani
Published: January 2009

A number of viruses, parasites and bacteria can be transmitted by blood. Blood seronegative for cytomegalovirus (CMV), effectively prevents CMV infection in seronegative bone marrow recipients. Such blood is available at larger blood transfusion services. Immune anti‐CMV globulin can also be helpful in protection of transplant recipients. Human T‐lymphotropic virus, type 1 (HTLV‐1) causing leukemia and myelopathy can also be transmitted by blood. Blood banks are considering donor screening in areas where the prevalence of this virus is significant. Parvoviruses that may cause crises in haemolytic anaemias present a potential hazard of transfusion. Malaria and syphilis are currently not very important infectious complications of transfusion, whereas prolonged storage of platelets has reemphasised the risk of bacterial growth in blood products.
Immunosuppressive effects of blood transfusion in anaesthesia and surgery
Authors: Salo Matti
Published: January 2009

The immunosuppressive effects of blood transfusion at surgical operations become manifest as enhanced graft survival, increased cancer recurrence and decreased patient survival, and increased susceptibility to postoperative infections. Blood transfusion in transplant recipients no longer offers this advantage when cyclosporine A is used. The deleterious effects of blood transfusion on the prognosis of some cancers found in the statistical analyses of retrospective studies are considered to be of increasing clinical importance. Therefore, unnecessary blood transfusions should be avoided and special attention directed to the use of autologous blood. Leucocyte‐free red blood concentrates are the least immunosuppressive homologous blood preparations. Conventional red blood cell concentrates may also be used in cancer patients until ongoing prospective randomized studies confirm that there is a true association between the use of homologous blood and inreased recurrence of cancer.
Safety of blood and blood products in Scandinavia today
Authors: Lindholm Annika
Published: January 2009

The safety of blood and blood products in Scandinavia today is high. An absolutely safe blood supply is, however, an unattainable goal. The dominating risk is transmission of non‐A, non‐B virus (NANBV). The calculated per blood unit risk is 1:200. The incidence of cirrhosis due to post‐transfusion hepatitis NANB is calculated to at most 0.1 % among recipients of blood components from about 5 donors. Other risk factors are transmission of hepatitis B virus (HBV), human immunodeficiency virus (HIV‐1) and cytomegalovirus (CMV). The prevalence of HBsAg among first time donors is about 0.05% (Sweden). In Scandinavia, anti‐HIV‐1 has been found in 0.001% of donations from start of screening in 1985 to December 1987. The prevalence was higher in Denmark, lower in Finland (and perhaps Iceland). The prevalence has declined during the last years. As of June 1988, 117 patients in the Scandinavian countries have been infected by blood components, all but 2 before screening was introduced. Besides these, 226 haemophiliacs have been infected by, in almost all cases, imported clotting factor concentrates before heat treatment was introduced. Most of the infected patients are still asymptomatic.

About 70% of blood donors have anti‐CMV, a few percent of which will transmit CMV‐infection, with severe symptoms, to immunosuppressed patients without anti‐CMV.
Hypotensive anesthesia and blood loss
Authors: Sollevi Alf
Published: January 2009

Controlled hypotension reduces blood loss during defined major surgical procedures, which in turn will minimize transfusion needs and thereby the risks of transmission of infectious diseases. There is no evidence that hypotension below 8 kPa (60 mmHg) (MAP) is associated with better blood‐sparing effects than a more moderate hypotension, but it will probably increase the risk of cardiovascular complications. Therefore, controlled hypotension, being a sophisticated technique, requires handling by an experienced anesthetist well aware of contraindications and the need for adequate monitoring for prevention of tissue ischemia. Large randomized and prospective studies are still warranted, especially for further evaluation of the risk‐benefit with controlled hypotension.
Regional anaesthesia and blood loss
Authors: Modig Jan
Published: January 2009

Epidural and spinal anaesthesia for various types of surgery offer advantages over general anaesthesia by decreasing blood loss and transfusion requirements. This paper focuses on the importance of the choice of anaesthesia on surgical blood loss in total hip arthroplasty. Haemodynamic differences, with lower arterial blood pressure, lower central venous blood pressure, and most importantly lower peripheral venous blood pressure in the surgical wound seem to explain the lower blood loss intra‐ and post‐operatively in patients given regional anaesthesia. These differences in haemodynamics give rise to less arterial, and notably less venous oozing of blood from the surgical area. The latter observation is strengthened by the significant correlations between the intraoperative peripheral venous blood pressure and the intraoperative blood loss. The reduction in blood loss and consequently the reduced transfusion requirements in regional anaesthesia are beneficial in decreasing the hazards and costs of homologous blood transfusion. Although impossible to quantify, reduced bleeding also greatly facilitates the surgeon's work.
Plasma volume substitution
Authors: Karanko Meri S.
Published: January 2009

Blood loss up to 10–15% of the total blood volume can be substituted by mere crystalloids. A quicker and more stable volume replacement can be accomplished with colloid solutions. Combination of artificial colloids (e.g., dextran 60, dextran 70 or hydroxyethyl starches with high degree of hydroxyethylation) with crystalloids (isotonic balanced solutions) produces a long lasting volume effect. Due to dose limitation recommendations for the artificial colloids, volume substitution may be continued, at a later stage, by albumin.
Predeposit autologous blood donation
Authors: Stehling Linda
Published: January 2009

Predeposit autologous donation for elective surgical procedures during which there is a potential requirement for transfusion is medically proven as safe and efficacious but significantly underutilized. The primary advantages are avoidance of transfusion‐transmitted disease and alloimmunization. Appropriate donor selection is essential. In general, there are no age or weight limits for donors. The incidence of adverse reactions is no greater in properly selected autologous donors than in homologous donors. Administration of oral ferrous sulfate allows many patients to meet all of their perioperative transfusion requirements. The blood is usually stored in the liquid state, but can be frozen.

The mere availability of autologous blood is not an indication for its reinfusion. The criteria for transfusion are similar to those for homologous blood. However, a more liberal interpretation may be appropriate in some clinical situations. The issue of disposition of predonated blood which is not transfused to donor‐patients remains unresolved. In some areas all units are discarded. In others, the blood can be administered to other patients if the donor met all the criteria for homologous donors and the blood tested negative for infectious disease markers.
Preoperative haemodilution
Authors: Lisander Björn
Published: January 2009

In preoperative haemodilution, blood is withdrawn before surgery while normovolaemia is maintained by infusion of cell free fluid. A surgical bleeding then entails a smaller loss of red cells. Reinfusion of the saved blood maintains normovolaemia, raises hematocrit and decreases the need for donor blood. Dilutional anaemia may endanger the oxygenation of the tissues. Tissue oxygenation can be upheld by an augmented and redistributed cardiac output and by a raised oxygen extraction. These compensatory mechanisms are less efficient in the presence of vascular stenosis, in particular in the myocardium which relies virtually exclusively on coronary vasodilatation. Major contraindications to preoperative haemodilution are, apart from coronary insufficiency, ventricular failure and valvular disease. Deleterious increases in cardiac oxygen consumption and/or heart rate may result from e. g. hypovolaemia, arterial desaturation and painful stimuli. The haemodilution procedure requires knowledge and vigilance in all involved personnel and gives best results if combined with other blood saving measures, like blood predeposit and intraoperative red blood cell salvage.
Survival compared to the general population and changes in health status among intensive care patients
Authors: ZAREN B. , BERGSTROM R.
Published: January 2009

In order to evaluate intensive care, all adult patients (980) admitted to a multidisciplinary intensive care unit (ICU) during 1 year were followed prospectively. The ICU mortality was 9,6%. One year after admission the survival was 73.6%. By that time the surviving patients had a further survival that was 96% of that of the general population. Of the 1–year survivors, 22.3% had deteriorated in health status compared to 3 months before the stay in ICU. In the admission groups with high mortality the survivors had a more pronounced deterioration in health status. Increased age and length of stay in the ICU were associated with higher mortality but not with changes in health status. We conclude that the outcome of intensive care can be evaluated by studying only the survival, since the survival rate is correlated to changes in health status among survivors in the different admission groups. One year after admission most of the surviving patients had regained their previous health status and their further survival was almost the same as that of the general population.