bluuebunny/crossref_metadata_2025 huggingface dataset:
The double mask‐a new local scavenging system for anaesthetic gases and volatile agents
Authors: Reiz S. , Gustavsson A.‐S. , Häggmark S. , Lindkvist A. , Lindkvist R. , Norman M. , Strömberg B.
Published: January 2009

The double mask, a new concept for local scavenging of anaesthetic gases escaping around face masks and from endotracheal tubes, is described. The system consists of a flexible silicone mask into which the anaesthetic gas mixture is led through a flow distributor which is necessary for adequate scavenging. A rigid transparent polysulphone shell surrounds the inner mask, and escaping gas is evacuated via the 3–4 mm slot between the two masks by a fan, centrally located outside the operating‐room. With this system, the anaesthetist's exposure to nitrous oxide during mask anaesthesia was reduced from 145 ± 29 to 15± 3 ppm (mean±s.‐e.mean, P< 0.001) and to halothane from 2.9± 1.1 to 0.5 ±0.1 ppm (mean ±s.e.mean, P<0.05), as measured in 32 patients aged 1–74 years. The double‐mask system provided safe and adequate mask anaesthesia, as judged from inspired concentrations of anaesthetic and fresh gases and transcutaneous and blood gases in 24 patients. The noise level was low with a mean value under regular operating‐room conditions around 45 dB(A) in the low frequency range. It is concluded that using the scavenging conditions provided by the system, the Swedish limits for anaesthesiologists' gas exposure could be reduced to the levels recommended by the US National Institute of Occupational Safety and Health (25 ppm for nitrous oxide and 0.5 ppm for halothane).
Severe acute propoxyphene overdose: plasma concentrations of propoxyphene and norpropoxyphene and the effect of dopamine on circulatory failure
Authors: Krantz T. , Thisted B. , Strøm J. , Angelo H. R. , Sørensen M. Bredgaard
Published: January 2009

Twelve patients with cardiovascular failure because of propoxyphene self‐poisoning were treated with dopamine. The patients responded favourably to dopamine infusion (2–17 μg/kg/min) with a dose‐dependent rise in systolic arterial blood pressure and a fall in central venous pressure and copious urinary output. Side effects during infusion were few, and in periods where dopamine infusion exceeded 10 μg/kg/min no tachyarrhythmias were seen. Eleven of the patients were treated on a respirator. Two patients were discharged from the ICU with signs of hypoxic brain damage, one of whom recovered completely after 2 weeks. Serum propoxyphene and norpropoxyphene were measured in nine patients. All but one patient had either propoxyphene or norpropoxyphene concentrations above 3 μmol/l.
Central haemodynamics and oxygen transport during CPPV with frequencies of 16 and 8 times per minute
Authors: Vuori A.
Published: January 2009

During the weaning period after 18 h of mechanical ventilation following open‐heart surgery, central haemodynamics, systemic oxygen transport and total oxygen consumption were assessed in a total of 11 patients receiving continuous positive pressure ventilation. Mechanical ventilatory rates of 16 and 8 times per minute were studied. Systemic arterial pressure, cardiac index, stroke volume index, left ventricular stroke work index, rate‐pressure‐product, and systemic oxygen transport were observed to be higher during the lower ventilatory rate. Because transmural right atrial and pulmonary capillary wedge pressures were also higher during ventilation with a frequency of eight times per minute, the lower frequency may impede venous return less. This might explain the differences found in central haemodynamics between the two ventilation frequencies.
A double‐blind trial of the analgesic properties of physostigmine in postoperative patients
Authors: Petersson J. , Gordh T. E. , Hartvig P. , Wiklund L.
Published: January 2009

A double‐blind clinical trial of the analgesic and antisedative effects of physostigmine was carried out on surgical patients (n = 60) during the first hours postoperatively. Pethidine and placebo were included for comparison in the double‐blind study. The degree of pain and sedation was estimated when the patient demanded analgesics and immediately before the administration of the test drug. The dosage administered i.v. was: physostigmine salicylate 2 mg, placebo=saline, or pethidine chloride 50 mg. After this, the same parameters were recorded at regular intervals. In addition, ventilatory rate, pulse rate, systolic blood pressure and side effects, if any, were noted. The results showed that physostigmine caused analgesia that was of the same magnitude as pethidine during the first 15 min, after which it decreased to the level of the placrbo at 30 min. An antisedative or arousal effect was recorded over a somewhat longer time period; after this, there was no difference between placebo and physostigmine. In contrast to pethidine, physostigmine caused no decrease in the ventilatory rate. The pulse rate and systolic blood pressure did not change in any of the groups. Although the durations of the analgesic and antisedative effects of physostigmine were short, the use of this drug may well be preferable to the use of e.g. naloxone when immediate alertness of the patient is wanted without causing an increase in postoperative pain.
A fatal case of malignant hyperthermia following isoflurane anaesthesia
Authors: Jensen A. G. , Bach V. , Werner M. U. , Nielsen H. K. , Jensen M. H.
Published: January 2009

To date, only two cases of malignant hyperthermia following isoflurane anaesthesia have been reported, neither of which were fatal. This case describes a very malignant form of hyperthermia after isoflurance in which the laboratory values were grossly abnormal, and with multi‐organ failure and death finally supervening.
A new nomogram facilitating adequate haemodilution
Authors: Zetterström H. , Wiklund L.
Published: January 2009

When using deliberate haemodilution to a certain haematocrit value (Hct), the appropriate preoperative blood volume of the patient must be determined and matched with the transfusion volume at a certain blood loss. In order to facilitate such calculations a nomogram was constructed, aiming for a final Hct of 33%. Preoperative Hct, height, weight and sex of the patient are input variables. After drawing three straight lines, the nomogram yields the normal blood volume and the acceptable pre‐transfusion blood loss (BL). This nomogram was used during surgery when the preoperative Hct exceeded 35%. Protocols from 100 patients bleeding more than 50% of their BL were studied. Blood loss was 1.1±0.6 I (mean±s.d.) ranging from 0.4 to 4.0 1. Fifty‐one of the patients received blood transfusion. This program resulted in a decrease of Hct (mean ± s.d.)from 41 ± 3% preoperatively to 33 ± 4% during the first 30 min postoperatively. Sixty‐three of the patients had a final Hct of 30–35%, 13 had 27–29% and one had 26%. The low values were most likely due to underestimation and consequent unsubstituted blood loss. In summary, the nomogram makes time‐consuming mathematical operations unnecessary. It was easy to use and the postoperative Hct was close to that desired in most patients.
Comparison of microbiological contents of compressed air in two Danish hospitals. Effect of oil and water reduction in air‐generating units
Authors: ØBerg B. , Bjerring P.
Published: January 2009

In a comparative study microbiological contamination of compressed air for medical use produced in oil‐lubricated and oil‐free compressors was investigated. Significantly lower levels of bacterial Contamination were observed in the air produced by oil‐free compressors; but if the air is transported to operating rooms and intensive care units through extensive pipeline systems previously contaminated by oil‐lubricated compressors, the bacterial count at peripheral air outlets remains unchanged.
Cardiac arrhythmias in familial amyloid polyneuropathy during anaesthesia
Authors: Eriksson P. , Boman K. , Jacobsson B. , Olofsson B. O.
Published: January 2009

There is an increased risk of anaesthetic complications in patients with myocardial disorders. The present paper concerns seven patients with familial amyloid polyneuropathy, who developed severe bradycardia or heart block during anaesthesia. Amyloid infiltration of the cardiac conducting tissues probably increases their susceptibility to anaesthetic agents. Dysfunction of autonomic nerves may also diminish cardiac impulse formation and conduction. In addition, the possibility of contributing succinylcholine‐induced hyperkalacmia cannot be excluded. There was a prompt response to infusion of isoproterenol in all patients so treated, but the insertion of a temporary pacemaker prior to anaesthesia should, nevertheless, be seriously ronsidered in this group of patients.
Gas exchange and lung morphology after surfactant replacement in experimental adult respiratory distress syndrome induced by repeated lung lavage
Authors: Berggren P. , Lachmann B. , Curstedt T. , Grossmann G. , Robertson B.
Published: January 2009

Severe respiratory insufficiency was induced in adult guinea pigs by repeated lung lavage. The animals were then ventilated for 75 min with 100% O2, insumation pressure 28/68 cmH2O (2.7/0.6–0.8 kPa), frequcnry 30/min, and 33% inspiration time. One group of animals (I) was treated with protein‐depleted porcinr surfactant, prepared by a combination of sucrose‐gradient centrifugation, heating to 90°C, and chloroform/methanol extraction. Another group (II) received the phospholipid fraction of porcine surfactant, isolared from minced lungs by chloroform/methanol extraction and liquid‐gel chromatography. Surfactant was administered in two 1‐ml doses (lipid concentration 90 mg/ml) instilled via the tracheal cannula about 15 and 45 min after the lavage procedure. Non‐treated, lavaged animals served as controls. After 75 min of ventilation, control values for Pao2 and Paco2 were 13.3 ± 6.8 and 6.8 ± 2.3 kPa (mean ± s.d.), respectively. The corresponding values in Group I of surfactant‐treated animals were 52.9 ± 7.7 and 4.4 ±1.I kPa, in Group II 53.5 ± 7.3 and 4.8 ±1.3 kPa (P<0.02–0.002). The two groups of surfactant‐treated animals also had significantly improved alveolar air expansion in histological sections, as reflected by increased alveolar volume density (0.67 ± 0.05 and 0.62 ± 0.11 vs. 0.45 ± 0.08 in controls; P<0.002). The benefits of surfactant replacement in this experimental model were thus similar to those previously observed in animal models of neonatal surfactant deficiency as well as in babies with respiratory distress syndrome (RDS). Our data suggest that surfactant replacement might have a therapeutic effect also in clinical adult RDS.
Glycopyrrolate during ketamine/diazepam anaesthesia A double‐blind comparison with atropine
Authors: Mogensen F. , Müller D. , Valentin N.
Published: January 2009

In a double‐blind study, the effects of atropine and glycopyrrolate (dosage ratio 2:l) following i.m. and i.v. administration were compared with respect to salivation, heart rate, and blood pressure before, during and after i.v. infusion anaesthesia with ketamine and diazepam for alloplastic hip or knee surgery in 30 patients above the age of 50 years. Given with the premedicant, the two drugs were equally effective in reducing salivation. A slight increase in heart rate was seen after atropine only (P<0.005). Increases in heart rate and blood pressure during induction of anaesthesia were similar in the two groups. A second dose of the test drug was given with neostigmine for reversal of neuromuscular blockade. Again, there were no statistically significant differences with respect to salivation, blood pressure, heart rate, nausea and/or vomiting, unpleasant dreams and arousal time.
Bioavailability of three formulations of intravenous diazepam
Authors: Fee J. P. H. , Collier P. S. , Dundee J. W.
Published: January 2009

It has been generally assumed that the bioavailability of different formulations of intravenous diazepam is identical. In a within‐subject crossover study using eight healthy volunteers, we have found that both thr initial and the overall plasma diazepam levels are significantly lower after both emulsion (Diazemuls®) and micelle preparations than after an organic formulation (Valium®). These findings are relevant to the interpretation of the results of past, present and future clinical studies involving intravenous diazepam. The studies with Valium and Diazemuls confirm the clinical impression of the lesser potency of the latter formulation.
Hemodynamic effects of atracurium, vecuronium and pancuronium during sufentanil anesthesia for coronary artery bypass
Authors: Waldmann C. S. , Wark K. J. , Sebel P. S. , Feneck R. O.
Published: January 2009

A study was undertaken to evaluate the cardiovascular effects of sufentanil, in combination with three different muscle relaxants, used as sole anesthetic with 100% O2 in 30 patients undergoing elective coronary artery vein graft surgery. Patients were randomly allocated to receive pancuronium (P), vecuronium [V) or atracurium (A) for muscle relaxation. All patients received 15 μg/kg sufentanil at induction followed by 5–10 μg/kg sufentanil prior to sternotomy. At the 95% level of significance no statistical difference was found for any of the measured and derived cardiovascular parameters between groups P, V and A, except for a decreased systolic blood pressure in the atracurium group after induction. Sufentanil in combination with pancuronium or vecuronium provided stable hemodynamic conditions throughout anesthesia. Atrarurium was less satisfactory. We conclude that there is no advantage to be gained, in the presence of beta blockade, from the use of the new generation muscle relaxants as compared to pancuronium during high‐dose sufentanil anesthesia for coronary artery vein grafting.
Effect of nitrogen on carbon dioxide elimination during continuous flow apneic ventilation in dogs
Authors: Babinski M. F. , Smith R. B. , Bunegin L. , Goldberg I.
Published: January 2009

Continuous endobronchial insumation of air in paralyzed animals (continuous flow apneic ventilation ‐CFAV) has been shown to maintain adequate oxygenation and carbon dioxide removal. CFAV in patients using oxygen resulted in adequate oxygenation but a mean rise in Paco2 of 0.6 mmHg/min (0.08 kPa/min). This experiment compared carbon dioxide removal in dogs with air and oxygen. Ten dogs were anesthetized and paralyzed, and CFAV was used for 1 h with either air or oxygen in a randomized fashion. Adequate oxygenation was obtained with air and oxygen. Normal Pacos levels were obtained with air; however, in the animals where oxygen was used, Paco2 levels rose to a mean of 6.45 ± s.e.mean 0.4 kPa (48.5 ± s.e.mean 3.2 mmHg).
Reversal of sedation and respiratory depression after anaesthesia by the combined use of physostigmine and naloxone in neurosurgical patients
Authors: Wiklund L.
Published: January 2009

A clinical trial of the combination of naloxone in alow dose (1–1.5 μg·kg‐1body weight) with physostigmine (0.5–1.0 mg i.v.) was made to elucidate whether this combination could reverse postanaesthetic oversedation in neurosurgical patients without increasing postoperative pain. The investigation was made following previous findings that physostigmine has analgesic properties in addition to its systemic antisedative and anticholinergic effects as well as a stimulatory effect on morphine‐depressed ventilation. Altogether 198 neurosurgical patients were investigated. The results showed that postanaesthetic oversedation can be safely treated by a combination of naloxone and physostigmine in the dosages named above, resulting in the rapid reversal of sedation, where opiates, neuroleptics and benzodiazepines have been used. In contrast, this combination has very little effect on sedation following the administration of agents such as halothane and isoflurane. In the great majority of patients (95%), the treatment resulted in excellent analgesia during the first postoperative hour. The incidence of nausea and vomiting was increased somewhat by this treatment, but these side‐effects could be minimized by decreasing the rate of drug administration. Physostigmine is contra‐indicated in patients having symptoms and signs similar to those of Parkinson's disease, and the dose of physostigmine should also be reduced to 0.5 mg i.v. in all patients over the age of 65.
Auditory evoked potentials during isoflurane anaesthesia
Authors: Schmidt J. F. , Chræmmer‐Jørgensen B.
Published: January 2009

Brainstem auditory evoked potentials (BAEP) were determined in 12 volunteers. The effect of isoflurane anaesthesia on BAEP was determined in six patients. Body temperature and end‐tidal CO2% were controlled. Increasing end‐tidal isoflurane concentration from 0.6–2.4% increased BAEP wave I, III and V latencies. The amplitude of wave V decreased with increasing isoflurane concentration. Thus a dose‐related change was demonstrated between end‐tidal concentration of isoflurane and BAEP latencies.
Self‐administered prophylactic postoperative positive expiratory pressure in thoracic surgery
Authors: Frølund L. , Madsen F.
Published: January 2009

Application of self‐administered postoperative prophylactic positive expiratory pressure (S‐PEP) treatment in addition to conventional physiotherapy was investigated in 75 patients undergoing thoracotomy. Twenty‐nine patients used a face‐mask set supplied with an expiratory resistance (S‐PEP group) arid 27 patients used a face‐mask set without resistance (control group). The observation period and postoperative treatment with the face‐mask was 3 days. In the S‐PEP group 13 patients developed radiographic atelectasis during the 3 postoperative days compared to eight patients in the control group (P>0.05). The postoperative Pao2: in the S‐PEP group was 0.36 kPa lower than in the control group (P>0.05). We conclude that application of S‐PEP postoperatively after thoracotomy in addition to conventional physiotherapy including early mobilization had no beneficial effect in preventing atelectasis, as evaluated by changes in blood gas tensions and chest roentgenograms.
A prospective analysis of 1400 pulmonary artery catheterizations in patients undergoing cardiac surgery
Authors: Damen J. , Bolton D.
Published: January 2009

During 1983 and 1984, 1305 patients underwent 1400 pulmonary artery (PA) catheterizations. Successful placement was achieved in 1397 (99.6%) of 1403 attempts. The catheters were inserted via the right internal jugular vein on 1364 occasions. The median duration of monitoring was 28 h with a range from 3 to 220 h. Central venous puncture complications included carotid artery puncture in 67 instances (4.8%) and pneumothorax in one patient. Insertion of the catheters was associated with supraventricular arrhythmias on 11 occasions, ventricular arrhythmias on 930 (66.4%), right bundle branch block on two and a total heart block on one occasion. Eighteen (2.3%) of the 794 cultured catheter tips were positive. An in situ time of more than 72 h was associated with a significantly higher percentage (7.2%) of positive tip cultures compared with an in situ time of less than 72 h (P<0.01). Repeated PA catheterization was not associated with significantly more complications than the initial catheterization. The results show that monitoring with a PA catheter in cardiac surgical patients is associated with a low incidence of morbidity.
Sudden bilateral hearing loss after spinal anaesthesia. A case report
Authors: Wang L. P.
Published: January 2009

A case of bilateral hearing loss following an otherwise uncomplicated spinal anaesthesia with bupivacaine is presented. It is suggested that a drop in intracranial pressure played a principal role in the development of this complication. Unless specifically sought for, minor auditory losses following spinal anaesthesia may be overlooked.
Respiratory depression following postoperative analgesia with epidural morphine
Authors: Madsen J. Vestergaard , Rybro L. , Schurizek B. A. , Husegaard H. C. , Joensen F. , Møller L. V. , Wernberg M.
Published: January 2009

Eighteen healthy patients subjected to operation for duodenal ulcer were allocated randomly to one of two regimes of analgesic treatment with epidural morphine. The analgesic regime was started either per‐ or postoperatively. Epidural morphine in doses of 4 mg was given until satisfactory pain relief was achieved. Paco2 and respiratory rate were measured hourly for 10 h and a nearly identical respiratory depression was found in the two groups. Peak Paco2‐‐values were seen in the 5th and 6th postoperative hour. The respiratory rate was initially high and declined during the first postoperative hours. Only one patient in each group had a pathologically low respiratory rate (8 min‐1), but this was transient and seen in thc 10th postoperative hour. The needs for epidural morphine on the first postoperative day were highest in the peroperative group. It is concluded that a peroperative start of pain treatment with epidural morphine does not affect the degree of respiratory depression or reduce the postoperative analgesic requirements.
Comparison of different methods of postoperative analgesia after thoracotomy
Authors: Asantila R. , Rosenberg P. H. , Scheinin B.
Published: January 2009

Fifty‐one patients scheduled for thoracotomy were included in a study involving five different methods of postoperative analgesia. Forty patients were randomly divided into: Group C, receiving intramuscular oxycodone on request following an intraoperative intercostal block; Group IC, intercostal blocks with 0.5% bupivacaine performed prior to surgery, 6 h later and on the first postoperative morning: Group EB, epidural bupivacaine as a continuous infusion of 0.25% bupivacaine (5 ml h‐1); Group EM4 epidural morphine 4 mg injected prior to surgery and on the first postoperative morning. In addition, a fifth group (Group EM6) of 11 patients received 6 mg of epidural morphine timed as in Group EM4, but these patients were automatically scheduled to be observed in the ICU. Additional intramuscular oxycodone was given on request to all patients. Group EB, EM4 and EM6 had lower numbers of requests than Group C. Pain intensity score was lowest (2.5 on a scale from 0 to 10, 3 h postoperatively) in Group EM6, and there was a statistically significant difference in pain intensity at 3 h between EM4 and EM6. The evaluation of cooperation and pain by the physical therapist revealed no differences between the groups. Postoperative blood‐gas analyses contained slightly elevated Pco2 values (6.0–7.3 kPa) in all groups. Postoperatively, only Group EB was devoid of Pco2 values above 7.3 kPa. Urinary retention was a common complication in the patients receiving epidural analgesia, occurring most frequently in Group EM6; 10 of the 11 patients had to be catheterized.
Postoperative analgesia by nicomorphine intramuscularly versus high thoracic epidural administration: Effects on ventilatory and airway occlusion pressure responses to CO2
Authors: Hasenbos M. , Simon M. , Egmond J. Van , Folgering H. , Hoorn P. Van
Published: January 2009

In this study the effects of nicomorphine, administered either intramuscularly or by high thoracic epidural route, on the ventilatory and airway occlusion pressure response to CO2 were investigated and compared. Twenty‐four patients scheduled for thoracic surgery were allocated randomly to postoperative pain relief by i.m. nicomorphine or by high thoracic epidural nicomorphine. The ventilatory response to 5% carbon dioxide was measured in all patients: first 1 day before operation, secondly on the first day after surgery immediately before nicomorphine administration and finally after the administration, at the moment when no further rise in end‐tidal Pco2 (Petco2) was measured. Respiratory response was assessed in two ways, by measuring minute ventilation (Ve) and mouth occlusion pressure (p0.1). There was a significant depression in ventilatory response to CO2 in the intramuscular group (P = 0.03) due to nicomorphine as assessed by the slope of Ve vs PetCO2 No significant depression was found in the epidural group, irrespective of measurement of VE, or P0.1. No significant shift of apnoeie threshold‐PETco2 was observed in either group.
CO2 production and breathing pattern during invasive and non‐invasive respiratory monitoring
Authors: Eriksson I. , Berggren L. , Hallgren S.
Published: January 2009

A computerized non‐invasive strain gauge system for respiratory monitoring is described and compared with pneumotachography. With the use of simultaneous capnography, changes in breathing pattern, end‐tidal PCO2 and CO2 production were evaluated during non‐invasive (NIM) and invasive breathing monitoring (IM) in 14 healthy subjects. An overall absolute difference between measured and calculated tidal volumes of 4.6 ± 3.47% (r = 0.97) was found. When switching from NIM to IM, tidal volume increased by 19%, and breathing frequency decreased by 11% with a 10% increase in minute ventilation. These changes were mainly accomplished by an increased respiratory drive with the timing component unaltered. During IM both end‐tidal PCO2 and CO2 production increased significantly as compared with those during NIM.
Subcutaneously implanted injection system for epidural administration
Authors: Andersen H. B. , Kjærgård J. , Eriksen J.
Published: January 2009

Six patients with advanced disseminated cancer were treated by operatively implanting a subcutaneous injection system for epidural opiate injection. The system consisted of an access port connected to an epidural catheter. The median period of treatment during hospitalization was 16 days (9–64). Two discharged patients were treated for 9 and 150 days, respectively. The median number of injections was 92 (48–542). Patient compliance was good in all cases. There was no case of displacement, kinking or occlusion of the cathetcrs. All patients experienced sufficient pain relief, although four, before epidural opiate treatment, had their pain triggered by activity.
Effect of chlorhexidine 0.5% on the hand bacterial flora
Authors: Sia R. I. , van der Goot L. , van Saene H. K. F.
Published: January 2009

The effects of cleaning the dorsal hand with chlorhexidine 0.5% in spirit was evaluated by bacteriological study in 45 adult patients. In the absence of cleaning it was found that the prevalent microorganisms were Staphylococcus epidermidis, Staphylococcus aureus, Streptococcus viridans and Enterobacteriaceae. Cleaning the hand with chlorhexidine 0.5% eliminated all bacteria except S. epidermidis and S. aureus. In both instances, the culture results showed that the microorganisms were present in very low growth density.
Adult respiratory distress syndrome after renal transplantation: A case report
Authors: Modig J. , Hedstrand U. , Wegenius G. , Tufveson G.
Published: January 2009

A potentially lethal case of “air‐borne” adult respiratory distress syndrome, most likely consequent to cytomegalovirus (CMV) pneumonitis, is described in a kidney transplant patient. It was characterized by confluent densities on both lung fields with peripheral zones of normal radiographic pattern and with one of the highest values of extravascular lung water reported in the literature, in the presence of a normal pulmonary capillary wedge pressure. When specific conservative therapy for curing a potentially lethal CMV pneumonitis after kidney transplantation fails, we suggest that transplantectomy should be considered.
Bradycardia during hypotension following release of a tourniquet in orthopaedic surgery
Authors: Jacobsen J. , Rørsgaard S. , Secher N. H.
Published: January 2009

Heart rate (HR) and mean arterial blood pressure (MBP) were followed in 39 consecutive patients during orthopaedic surgery with the leg exsanguinated by an inflatable tourniquet around the thigh. The rirculation was stable in all patients until release of the tourniquet. Following release of the tourniquet MBP derrcased from 94 ± 5 (s.e. mean) to 45 ± 12 mmHg (12.5 ± 0.7 to 6.0 ± 1.6 kPa) (P<0.005) in 10 patients, while it remained stable in the others. At the same time the hypotensive group showed a decrease in HR from 83 ± 6 to 67 ± 3 beats min‐l (P<0.005) while no significant change in HR was seen in the normotensive group. The hypotensive group was older (57 ± 8 versus 50 ± 4 years (P<0.05)), had a larger blood loss during surgery (2.9 ± 1.2 versus 0.7 ± 0.3 ml kg‐1 (P< 0.005)), and the duration of the operation was longer in this group (120 ± 14 versus 60 ± 27 min (P<0.001)). It is suggested that the characteristic deviation of HK in conjunction with hypotension following release of a tourniquet is bradycardia.
Positive‐pressure ventilation at moderately high frequency in newborn infants with respiratory distress syndrome (IRDS)
Authors: Sedin G.
Published: January 2009

In 24 seriously ill newborn infants with respiratory distress syndrome (IRDS) and ensuing respiratory failure., high‐frequency positive‐pressure ventilation was administered. The mean gestational age of the infants was 32 ± 3 weeks. In the infant ventilator employed, the compressible volume had been reduced in order to give higher flow rates but lower intratracheal pressures. The ventilation frequency was kept constant at 60—66 per min and the insufflation period at 32–35% of the ventilatory cycle. A positive end‐expiratory pressurc (PEEP) of 0.2—0.6 kPa was used. Arterial PCO2 was maintained at 4.0–5.3 kPa and Po2 at 8.5—10.5 kPa by adjusting the gas flow through the patient circuit, the peak tubing pressure, the PEEP and the oxygen concentration in inspired gas. High‐frequency positive‐pressure ventilation improved oxygenation and gave adequate alveolar ventilation in all infants, in most cases at a low peak pressure. Only one infant developed pneumothorax during intermittent positive pressure ventilation, and in no infant did bronchopulmonary dysplasia or retrolental fibroplasia occur. One infant died from intracranial haemorragc during the ventilation period, giving a survival rate of 96%.
Inhibition of phrenic nerve activity during positive‐pressure ventilation at high and low frequencies
Authors: Norsted T. , Jonzon A. , Rondio Z. , Sedin G.
Published: January 2009

A study was made to determine whether the ventilatory pattern, in terms of ventilatory frrqurnry, insufllation period and end‐expiratory pressure, influences the arterial blood gas level at which central inspiratory activity is inhibited, and whether further expansion of the lung changes this activity. This was accomplished by measuring arterial pH and blood gases, and intratracheal, intrapleural and transpulmonary pressurrs, at the setting of positive‐pressure ventilation causing inhibition of phrenic nerve activity in chloralose‐anaesthetized cats. Spontaneous breathing movements were prevented by muscle relaxation. Ventilatory frequencies of 15–120 breaths per minute (b.p.m.) were studied at at least two different insumation times. A volume‐controlled ventilator with a large compressible volume was used in the frequency range 15–45 b.p.m. and a constant flow respirator with a low‐compressible volume in the range 45–120 b.p.m. A much lower Pco2 was needed for phrenic nerve activity to be inhibited at a ventilatory frequency of 15 b.p.m. than at higher frequencies. At ventilatory frequencies between 30 and 120 b.p.m. inhibition ronld be achieved at a higher Pco2, within the normal range. The inhibition of phrenic nerve activity tended to he less stable when PEEP was added during ventilation with a long insumation period, but PEEP did not influence the arterial blood gas level at which inhibition occurred. In the lower frequency range of 15–30 b.p.m., inspiratory activity was observed with bursts at the same rate as the insumations given by the ventilator. The intratracheal peak pressures at ventilation causing inhibition of phrenic nerve activity decreased with increasing ventilatory frequencies. The intratracheal peak pressure was always highest at 15 b.p.m., and at each ventilatory frequency it was higher when PEEP was used.
Halothane hepatitis in a prospective study of postoperative complications
Authors: Zaric D. , Larsen S. F. , Jacobsen E. , Olesen K. H. , Ranek L.
Published: January 2009

In a prospective study comprising 2609 consecutive surgical patients, of whom 1166 were anesthetized with halothane, four cases of hapatitis were encountered. The incidence of hepatitis among those who received halothane was 1:292 in our material. The high incidence may be explained by the recognition of milder forms of hepatitis and by the selection of the series (over 40 years). Serum alanine amiriotrarisfcrase should be investigated in all patients with postoperative pyrexia of unknown origin if mild forms of halothanc hepatitis are to be discovered. The patient's history should be carefully examined for prrvious postoperative pyrexia of unknown origin following halothane anesthesia, in which case other anethetics should be chosen.
Cardiovascular and blood gas responses to inhaled anaesthetics in normoxic and hypoxic dogs
Authors: Naeije R. , Lambert M. , Lejeune P. , Leeman M. , Deloof T.
Published: January 2009

Changes in haemodynamics and blood gases were investigated before and after administration of 0.5, I and 1.5 MAC of halothane, enflurane and isoflurane in respectively 7, 7 and 9 dogs ventilated alternatively with a fraction of inspired O2 in N2 (FiO2) of 0.4 and with brief periods (10 min) of Fio2 of 0.1. Anaesthesia was induced with pentobarbital and the animals were paralysed with pancuronium. Acute hypoxic challcnges with Fio2 of 0.1 consistently decreased arterial Po2 to 3.5–4.5 kPa and increased pulmonary vascular resistances by 60–100%. At identical inspired concentrations, as expressed in MAC: units, all thrrr inhaled anaesthetics induced a broadly comparable dose‐related decrease in systemic blood pressures, due to a depression in cardiac performance as well as a reduction in systemic vascular resistances. Enfluraw was the most potent myocardial depressor and isoflurane the most potent vasodilator, halothane being intermediate. Oxygen deprivation was associated with some enhancement of the cardiovascular depressant effects of the inhaled anaesthetics but, in spite of this, matching of 02 transport to tissue O2 demand appeared to be improved, probably in relation to a concomitant reduction in metabolic rate. Only isoflurane inhibited the hypoxic pulmonary pressor response, and this was associated with a slight deterioration in arterial oxygrnation in both normoxic and hypoxic conditions.
Selective effect of sufentanil on Group III (A delta) and Group IV (C) somatosympathetic reflexes
Authors: Swenzen G. Odensjo , Chakrabarti M. , Sapsed‐Byrne S. , Wnrrwam J. G.
Published: January 2009

The effect of sufentanil on somatosympathetic reflexes and the subsequent reversal of its effects by naloxonc have been observed in dogs anaesthetised with a‐chloralose, paralysed with suxamethonium and artificially ventilated. When the drug was infused at a rate of 2.5 μg kg‐lmin‐1the late long latency response evoked by Group IV (C) fibres was totally abolished at a mean dose of 6.40 pg kg‐1(± 0.99 μg kg‐1) (s.e. mean), while retaining a substantial part of the early short latency response evoked by group III (A delta) fibrrs; subsequently, during the infusion, this response was also totally abolished at a mean dosr of 26.2 pg kg‐1(±3.2 mg kg‐1). The administration of naloxone (2 mg i.v.) completely reversed the effects of sufentanil within 3–5 min in different preparations. Some of the implications of these results are discussed.
Correction of metabolic alkalosis by HCl and acetazolamide: effects on extracellular and intracellular acid‐base status in ratsin vivo
Authors: Rothe K. F. , Heiler N.
Published: January 2009

Extracellular plasma pH (pHe) of nephrectomized male or female Sprague‐Dawley rats was changed by infusion of either sodium bicarbonate or HCl to predetermined values in the pH rangc of 7.53–7.14, and then held constant for 2 h. Intracellular pH (pHi) of the liver, heart, brain, and two skeletal muscle groups as calculated from the distribution of14C‐labelled DMO (5.5‐dimethyl‐2,4‐oxazolidinedione) was compared to corresponding tissues of a control group and rats treated with the carbonic anhydrase inhibitor acetazolamide (Diamox). When compared to control, changes of the extracellular pH in malr or fcmalr rats were followed by similar effects on pHi in the investigated tissues. At the same extracellular pH three were no statistical differences between pHi values of HC1 or acetazolamide treated rats, though thc arterial Pco2following acetazolamide administration was significantly increased when compared to control or thr corresponding HCl group. This study shows that administration of acetazolamide or HCl rcsrilts in a dosrdependent decrease of plasma and tissue pH, and that both agents may be used as a logical and safe therapy during severe metabolic alkalosis in rats.
Anaesthetic temperature and shivering in epidural anaesthesia
Authors: Ponte J. , Collett B. J. , Walmsley A.
Published: January 2009

The mechanism of shivering during epidural analgesia remains unclear. This study investigates the role of the temperature of the local anaesthetic injected extradurally. Forty patients admitted for elective caesarean section under epidural anaesthesia were studied; 20 were given bupivacaine warmed to 37°C: (warm group) and 20 were given hupivacaine stored at 4°C (cold group); the occurrence of shivering in both groups was recorded. The overall incidence of shivering was 27.5%; two patients of the warm group and nine patierits of the cold group shivered. This difference was statistically significant (P<0.03). The results suggest that there are thermosensory mechanisms in the human spinal canal. In our view, epidural anaesthetic solutions should be warmed to body temperature prior to injection to reduce the incidence of shivering.
The influence of fentanyl on the cardiovascular effect of suxamethonium
Authors: Engék J. , Sørensen M. , ØStergaard D. , Skovgaard L. T. , Viby‐Mogensen J.
Published: January 2009

The influence of fentanyl on the cardiovascular effect of a single dose of suxamethonium was evaluated during thiopentone N2O/O2anaesthesia. Sixty adult patients were randomly allocated to three groups. In one group (control group) no fentanyl was given. In two groups fentanyl 0.002 mg/kg and 0.004 mg/kg, respectively, was given before induction of anaesthesia. Three minutes after the injection of suxamethonium 1 mg/kg, both heart rate (HR) and mean arterial pressure (MAP) in the two groups receiving fentanyl were significantly lower than in the control group. However, the absolute changes were small and no dose‐related effect was seen. An estimation of the change in HR following suxamethonium was made using as predictors initial HR before induction of anaesthesia, age, sex, and the injection of fentanyl. The higher the initial HR, the greater was the chance of a decrease in HR following suxamethonium. Injection of fentanyl lowered the threshold HR above which a decrease was to be expected following injection of suxamethonium. This effect was most pronounced among the younger patients. It is concluded that injection of fentanyl potentiates the decrease in HR sometimes seen after a single dose of suxamethonium and that this effect is influenced by HR before induction of anaesthesia and by age of the patient.
Accidental hypothermia Review of the literature
Authors: Lønning P. E. , Skulberg A. , ÅByholm F.
Published: January 2009

The pathophysiology and treatment of accidental hypothermia are discussed. Special attention is paid to the pathophysiologic problems of rewarming. For severely hypothermic patients we would recommend peritoneal dialysis as the method of choice for rewarming in a hospital situation. In a “field situation” passive or slow active rewarming is recommended.
Diclofenac and oxycodone in treatment of postoperative pain: a double‐blind trial
Authors: Nuuttnen L. S. , Wuolijoki E. , Pentikäinen I. T.
Published: January 2009

The effects of a prostaglandin synthesis inhibitor (diclofenac, Voltaren®) and an opiate (oxycodone, Oxa‐nest®) on postoperative pain were compared. Included in the study were 85 candidates for various operations. Patients requesting an analgesic were given either 75 mg of diclofenac or 10 mg of oxycodone as an intramuscular injection. The onset of analgesic effect occurred within 13 ± 4 min with oxycodone and within 16 ± 8 min with diclofenac. The analgesic effect of diclofenac was slightly weaker than that of oxycodone (on a pain scale of 1–4, 1.6/2.1 after 0.5 h and 1.5/1.8 after 1 h). The patients again asked for an analgesic after an average of 4.6 h in the oxycodone group and after an average of 6.1 h in the diclofenac group. The average number of injections required until the first postoperative morning was 2.5 in the oxycodone group and 1.8 in the diclofenac group. Side‐effects: 21 patients in the oxycodone group reported a total of 39 side‐effects and eight patients in the diclofenac group a total of 10 side‐effects. Diclofenac is an alternative to opiates in the management of postoperative pain. It is especially useful in patients in whom opiates cause side‐effects.
The incidence of cardiac arrhythmias and arterial hypotension subsequent to standardized surgical stimuli in patients undergoing thoracotomy. With reference to enflurane and halothane
Authors: Sørensen O. , Waaben J. , Andersen K. B. , Skovsted P.
Published: January 2009

A main factor which might cause cardiac arrhythmias and arterial hypotension during thoracic operations is surgical manipulation around the pericardium and the lung hilus. Halothane and enflurane were compared as to the occurrence of arrhythmias and hypotension caused by standardized surgical stimulation. Twenty‐eight patients scheduled for thoracotomy were studied. The patients were selected in randomized order, and the anaesthetic agent in use was unknown to the surgeon. ECG, intra‐arterial blood pressure and central venous pressure were recorded continuously. Six patients in the halothane group (n= 14) and nine patients in the enflurane group (n=14) developed premature atrial contractions and nodal rhythm, while nine patients in the halothane group and five in the enflurane group developed a fall in systolic blood pressure of more than 20 mmHg (2.7 kPa). No statistically significant difference in the occurrence of cardiac arrhythmias and hypotension was found between the two anaesthetic groups.
Benzodiazepines and neuromuscular blocking drugs in patients
Authors: Driessen J. J. , Crul J. F. , Vree T. B. , Egmond J. van , Booij L. H. D. J.
Published: January 2009

The interaction between four benzodiazepines (diazepam, lorazepam, lormetazepam and midazolam) and two nondepolarizing neuromuscular blocking drugs (vecuronium and atracurium) was investigated in 113 patients during general anaesthesia. Neuromuscular function was monitored by recording the mechanical twitch tension of the adductor pollicis muscle of the thumb in response to ulnar nerve stimulation with single supramaximal stimuli of 0.2 ms at 0.1 Hz. In the first group of patients a benzodiazepine (diazepam 20 mg, lorazepam 5 mg, lormetazepam 2 mg or midazolam 15 mg), was injected i.v. 15 min before a single bolus of vecuronium 45 μg kg‐1. In the second group of patients suxamethonium 1 mg kg‐1 was given for endotracheal intubation, and 30 min later the patients received atracurium 200 μg kg‐1. Fifteen min before injection of atracurium one of the same benzodiazepines as in the first group was injected i.v. Comparisons were made with control patients receiving thiopentone. Neither benzodiazepine caused significant potentiation of neuromuscular blocking agents in comparison with control. With midazolam, however, the duration to 25% and to 75% recovery of the twitch height after vecuronium was significantly longer than with diazepam. The time to 25% recovery of the twitch height after atracurium was significantly longer in patients receiving midazolam than in those receiving diazepam. The recovery index was not influenced by the four benzodiazepines.
The effects of ornipressin and adrenaline on lignocaine nerve blocks
Authors: Prokopiou A. A. , Pateromichelakis S. , Rood J. P.
Published: January 2009

An electrophysiological method measuring nerve conduction following the electrical stimulation of a sciatic nerve branch in anaesthetised rats was used to evaluate under strictly controlled conditions the effects of 1:100000 adrenaline and of 0.03 IU ml‐1 ornipressin on the speed of onset, depth and duration of lignocaine anaesthesia. It was shown that compared with plain lignocaine, lignocaine with ornipressin produced shorter onset of anaesthesia and improved its depth and duration. Adding adrenaline to lignocaine merely extended its duration of action. Ornipressin, therefore, even at low concentration, can be considered as a viable alternative vasoconstrictor to adrenaline, the use of which is undesirable in some categories of patients.
Halothane‐associated liver damage and renal failure in a young child
Authors: Hals J. , Dodgson M. S. , Skulberg A. , Kenna J. G.
Published: January 2009

A case of halothane‐associated liver damage and renal failure is described in an 18‐month‐old girl after her third halothane anaesthetic. There had been two uneventful enflurane anaesthetics. The diagnosis was confirmed by detecting antibodies specific for halothane‐associated liver failure using a recently developed enzyme‐linked immunosorbent assay.
Oxygen analyzers in anaesthesia: performance in a simulated clinical environment
Authors: Bengtson J. P. , Sonander H. , Stenqvist O.
Published: January 2009

Nine commercial oxygen analyzers were tested in a laboratory model simulating clinical anaesthesia conditions. Fifteen test situations were used in order to study the effects of nitrous oxide, humidity, positive end‐expiratory pressure, halothane, enflurane and isoflurane. Errors exceeding 8 vol% were not uncommon, the dominating source of error being humidity. Analyzers with efficient dehumidification of gases before analysis performed better than analyzers without this property.
Peroperative buprenorphine: do high dosages shorten analgesia postoperatively?
Authors: Pedersen J. E. , Chræmmer‐Jørgensen B. , Schmidt J. F. , Risbo A.
Published: January 2009

Fifty‐two patients undergoing biliary surgery were investigated in a prospective randomized study, in which they received buprenorphine 10, 20, 30, and 40 μg.kg‐1, respectively, as sole intravenous analgesic as a bolus 15 min before induction of anaesthesia. The anaesthetic was uneventful in all four groups, although when receiving 10 and 20 μg kg‐1 almost two‐thirds of the patients needed supplemental analgesics during the operation. When receiving buprenorphine in the dosages of 30 and 40 μg‐kg‐1, 50% of the patients requested an analgesic within 5 min of extubation. In contrast, when receiving 10 and 20 μg‐kg‐1 none of the patients requested an analgesic within 1 h of the operation. These findings accord to a certain extent with the presence of a bell‐shaped dose‐response curve for buprenorphine in humans.
Postoperative pain relief with high‐dose epidural buprenorphine: a double‐blind study
Authors: Gundersen R. Y. , Andersen R. , Narverud G.
Published: January 2009

Forty‐five patients scheduled for major abdominal or intrathoracic surgery were assigned at random to two different groups. One group received 0.3 mg and the other 0.9 mg of buprenorphine epidurally to abolish postoperative pain. The first dose was given immediately upon arrival in the ICU, irrespective of pain. Subsequent medication was given on demand. The duration of action and side‐effects were recorded. Both doses produced excellent and long‐lasting pain relief, but no statistically significant difference was found between the groups, with regard to either the duration of action or the occurrence of side‐effects.
Postoperative lymphocytopenia and leucocytosis after epidural and general anaesthesia
Authors: Jakobsen B. W. , Pedersen J. , Egeberg B. B.
Published: January 2009

Few investigations have demonstrated a positive effect of epidural blockade on the leucocytosis and lymphocytopenia secondary to surgery. Thirty elderly patients undergoing total hip replacement were randomly allocated to two groups: epidural analgesia and general anaesthesia. The leucocyte and lymphocyte counts per‐ and postoperatively were registered. Significant leucocytosis and lymphocytopenia were found in both groups, but no significant difference was found between the groups.