bluuebunny/crossref_metadata_2025 huggingface dataset:
Epidural catheters of the multi‐orifice type: dangers and complications
Authors: Beck H. , Brassow F. , Doehn M. , Bause H. , Dziadzka A. , Schulte J.
Published: January 2009

A study on epidural catheters of the multi‐orifice type, investigating their tendency to epidurovasal (with an intravascularly positioned catheter tip) and epidurosubarachnoid (with the catheter tip inserted in the subarachnoid space) malpositioning, was conducted on 113 patients using clinical and radiological criteria as controls. Of the improperly placed catheters, 13 were in an epidurovasal (11.5%) arid one was in an epidurosubarachnoid (0.9%) position. The findings demonstrate the occasional hazardous dual compartmen‐tal misplacement of multi‐orifice catheters, in which a distal opening can lie intravascularly or within the subarachnoid space, while a proximal orifice simultaneously retains normal access to the epidural space. The insufficiency of controlling or even recognizing such improperly placed catheters which are only partially in the epidural space, as well as the danger of causing a secondary dural or vascular perforation with epidural catheters, is discussed. Since epidural catheters of the multi‐orifice type apparently represent an inherent, vital danger due to their construction (regardless of the catheter material and workmanship), they should no longer be used.
Splanchnic blood flow during halothane‐relaxant anaesthesia in elderly patients
Authors: Tokics L. , Brismar B. , Hedenstierna G.
Published: January 2009

We have previously found that halothane‐relaxant anaesthesia in elderly patients causes a change towards a hyperkinetic circulation, with a decrease in the arterial‐mixed venous oxygen content difference. This could be attributed to vasodilation. In the present study the splanchnic contribution to these changes was investigated. Nine patients were studied during halothane‐relaxant anaesthesia prior to surgery. During anaesthesia splanchnic blood flow was markedly reduced, while splanchnic oxygen uptake decreased only moderately compared with the awake level. This resulted in an increase in splanchnic oxygen extraction. It is concluded that the splanchnic vascular bed does not contribute to thr “hyperkinetic” circulation during halothane anaesthesia.
Hypertensive response to thiopental in man during cardiopulmonary bypass
Authors: Pauca A. L. , Roy R. C.
Published: January 2009

We report the effect of 250 mg of sodium thiopental on vascular tone at constant blood flow in 26 patients undergoing cardiopulmonary bypass while the ascending aorta was cross‐clamped. Light anaesthesia was effected with fentanyl and enflurane, muscle relaxation with pancuronium. After a latent period of 10.5 ± 0.7 s there was a hypertensive response of 9.8 k 0.5 s duration and of 21.45 1.7 mmHg (2.8 ± 0.2 kl'a) magnitude; this was followed by hypotension of 39.6 ± 4.2 s duration and of 18.4 ± 1.9 mmHg (2.4 ± 0.3 kPa) magnitude. There was a statistically significant inverse correlation between the hypertension and body temperature (P = 0.005); the time to onset of hypertension correlated directly with pump volume (P = 0.001), weight of the patient (P=0.03), and cross‐clamp time before the drug was given (P= 0.002), and correlated inversely with the serum sodium concentration (P=0.001). The duration of hypertension was inversely related to the plasma bicarbonate (P=0.01) and body temperature (P=0.04). The duration of hypotension was significantly longer in women (P=0.0001) and was directly related to the duration of cross‐clamping (P=0.0007), to pH (P= 0.0016), and to Pco2 (P=0.04). We speculate that thiopental induced the hypertensive response due to a potentiation of the vasoconstrictive (local) effect of norepinephrine, and induced the hypotensivc response by a central nervous system effect. Thiopental had no apparent effect on venous tone.
Asystole and bradycardia in adult patients after a single dose of suxamethonium
Authors: Inoue K. , Reichelt W.
Published: January 2009

Two cases of cardiac asystole and one case of severe bradycardia were seen following a single injection of suxamethonium in a series of 46 adult patients in whom anaesthesia was induced with fentanyl and etomidate. It is suggested that the vagomimetic effects of fentanyl and, possibly also of etomidate, may contribute to the enhancement of the bradycardic effects of suxamethonium.
Anaesthesiological complications in renal transplantation: a retrospective study of 500 transplantations
Authors: Heino A. , Orko R. , Rosenberg P. H.
Published: January 2009

This retrospective study consisted of 500 consecutive renal transplantations performed between September 1977 and September 1981. Preoperatively, congestive heart failure was registered in 262 cases (53.07;) and blood pressure disease in 352 cases (71.3%). The total number of patients with ischaemic heart disease was 22 (4.5%). General anaesthesia was given in 493 and regional anaesthesia in seven caws. In general anaesthesias, tubocurarine was the main relaxant and halothane the main inhalation agent used. Major complications during anaesthesia were blood pressure changes with a higher incidence of hypotension (49.60/) than hypertension (26.8%). Severe cardiac arrhythmias were rare and no intraoperative deaths occurred. One patient was successfully resuscitated in the ICU postoperatively, this being possibly related to hypoventilation caused by prolonged muscular relaxation. Other rare complications included one pneumothorax, one haemo‐ and hydrothorax, and two large haematomas all caused by Preoperative central venons cannulation. In 69 cases (14.0%) additional neostigmine doses and in 34 cases (6.9%) naloxone was given at the end of anaesthesia. Pneumonia during the first postoperative week was recorded in 11 rases (2.2%), and occurred only in patients who received general anaesthesia. One of the three patients who died during the first week developed pneumonia postoperatively.
3‐in‐1 lumbar plexus block for muscle biopsy in malignant hyperthermia patients. Amide local anaesthetics may be used safely
Authors: Gielen M. , Viering W.
Published: January 2009

A 3411–1 lumbar plexus block with the aid of a nerve stimulator was performed in 32 patients and a psoas compartment block was performed in five patients for muscle biopsy of the upper leg for diagnosis of malignant hyperthermia (MH) susceptibility. Twenty‐two patients were found to be MH susceptible by the in vitro contracture test. Twenty patients received 40 ml prilocaine 1.5% with epinephrine 1:200000 and two received 40 ml bupivacaine 0.5% with epinephrine 1:200000 without any untoward reaction. The 3‐in‐1 block provides a high success rate and excellent analgesia for muscle biopsy of the upper leg. Amide local anaesthetics are safe in MH‐susceptible patients.
Fresh gas flow in coaxial Mapleson A and D circuits during spontaneous breathing
Authors: Jonsson L. O. , Zetterström H.
Published: January 2009

In a lung model simulating spontaneously breathing halothane anaesthesia, the rebreathing characteristics of the coaxial Mapleson A (Lack circuit) and D (Bain circuit) systems were tested. Using decrrasing fresh gas flows (Vf), the end‐tidal carbon dioxide fraction (Faco2) was monitored and the point of rrbreathing (R.P.) detected. The effects of changes in minute volume (Ve), dead‐space to tidal volume ratio (Vd/Vt) and carbon dioxide elimination (Vco2) were studied. The effect of increased tidal volumes (Vt) on Faco2 was investigated for some different fresh gas flows (Vf). The Vf/Ve ratio for R.P. in the Bain circuit was approximately 2 and in the Lack circuit 0.88. In both circuits an increase in Ve and a decrease in the Vd/Vt ratio resulted in higher demands on Vf if rebreathing was to be avoided. The latter effect was much more pronounced in the Lack circuit. In neither system did any changes in Vco2 affect the rebreathing characteristics. The conclusion was drawn that the Lack system is a much better choice concerning the fresh gas flows for anaesthesia with spontaneous breathing than the Bain system. It was also concluded that the fresh gas flows recommended by Humphrey for the Lack system (it. 51 ml × min‐1 ± kg b.w.‐1) and by the manufacturers for the Bain system (i.e. 100 ml × min‐1 × kg b.w.‐1) are inadequate and should be increased if a considerable degree of rebreathing is to be avoided.
Haemodynamic effects of nifedipine in patients undergoing coronary artery bypass surgery
Authors: Hess W. , Meyer C.
Published: January 2009

Forty patients scheduled for elective aortocoronary bypass surgery were entered in a double‐blind study set up to compare the haemodynamic effects of 20 mg nifedipine (n = 20) and placebo (n = 20), both administered with the premedication. Global left ventricular function was normal in all patients. Anaesthesia was induced and maintained with standardized doses of fentanyl, flunitrazepam, and pancuronium together with 50% N2O. Cardiovascular responses to anaesthesia, intubation, skin incision, sternal retraction, and aortic manipulation were investigated. Throughout the study nifedipine produced a marked decrease in systemic vascular resistance. The reduction of left ventricular afterload was associated with an increase in cardiac index. In contrast to other reports, we observed no severe hypotension after nifedipine administration. Mean arterial pressure in patients from the nifedipine group was lower than in the placebo group only prior to anaesthesia. Since no negative drug interactions between nifedipine and the anaesthetic agents were observed, we conclude that the established cardiovascular benefit of nifedipine should be continued during anaesthesia.
Effects of repeated bupivacaine administration on sciatic nerve and surrounding muscle tissue in rats
Authors: Kyttä J. , Heinonen E. , Rosenberg P. H. , Wahlström T. , Gripenberg J. , Huopaniemi T.
Published: January 2009

The effects of repeated administration of 0.5% bupivacaine or saline into the sciatic notch of rats were studied by light microscopy, electron microscopy and a neurophysiological technique. Very severe myositis, including local necrosis, developed in six of 12 rats treated twice daily with 1 ml bupivacaine for either 3 or 7 days. A 3‐h infusion of 1.5 ml 0.5% bupivacaine resulted in minor injury to muscle tissue. A marked degree of disruption and vacuolization of myelin sheaths was evident in nerves exposed to bupivacaine for 3 days. Lymphocyte accumulation was confined to the area surrounding the nervous tissue in 7 of 10 of the preparations from rats treated for 3 days or by a 3‐h infusion. No histological changes were detected in nerve and muscle tissue from the opposite extremity exposed to saline. After a recovery period of 3 weeks, no differences in the nerve or muscle histology were seen between samples from bupivacaine‐ or saline‐treated animals. The amplitude of the compound action potential of sciatic nerves was, however, significantly lower after bupivacaine treatment (7 days, 1 ml twice daily). Thus, impaired function may continue despite the lack of histological intraneural injury.
CBF and CMRo2 during craniotomy for small supratentorial cerebral tumours in enflurane anaesthesia. A dose‐response study
Authors: Madsen J. B. , Cold G. E. , Eriksen H. O. , Eskesen V. , Blatt‐Lyon B.
Published: January 2009

In 14 patients with supratentorial cerebral tumours with midline shift < 10 mm, cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMR02) were measured twice on the contralateral side of the craniotomy, using a modification of the Kety & Schmidt method. For induction of anaesthesia, thiopental, fentanyl and pancuronium were used. The anaesthesia was maintained with enflurane 1% in nitrous oxide 67%. Moderate hypocapnia to a level averaging 4.3 kPa was achieved. The patients were divided into two groups. In Group 1 (n=7), 1% enflurane was used throughout the anaesthesia, and CBF and CMR02 measured about 70 min after induction averaged 30.1 ml 100 g‐1 min‐1 and 1.98 ml O2 100 g‐1 min‐1 respectively. During the second CBF study 1 h later, CBF and CMR02 were unchanged (P>0.05). In Group 2 (n = 7), the inspiratory enflurane concentration was increased from 1 to 2% after the first CBF measurement. In this group a significant decrease in CMR02 was observed, while CBF was unchanged. In six patients EEG was recorded simultaneously with the CBF measurements. In patients subjected to increasing enflurane concentration (Group 2), a suppression in the EEG activity was observed without spike waves. It is concluded that enflurane induces a dose‐related decrease in CMR02 and suppression in the EEG activity, whereas CBF was unchanged.
Work practices relating to intubation and associated procedures in intensive care units in Sweden
Authors: Mehta S. , Mickiewicz M.
Published: January 2009

A survey into the current usage of tracheal tubes and associated procedures, such as various sedation regimes and antacid therapy, in intensive care units was carried out in Sweden by sending a questionnaire to physicians in charge of intensive care units in 70 acute hospitals which included seven main teaching hospitals. The purpose of the survey was to see how far the recent advances in tube and cuff design and awareness of the problems caused by prolonged therapeutic paralysis in intensive care units have influenced the attitudes and work practices of physicians in Sweden. Forty‐nine replies were received (a 70% response rate). All hospitals used polyvinyl chloride tubes of Magill design, with high residual volume, low pressure cuffs. Intensive care units in 85.7% of teaching hospitals and 47.6% of non‐teaching hospitals preferred the nasal route for intubation. Most non‐teaching hospitals used a size 7 tube in both adult male and female patients for nasal intubation. The majority of units changed from tracheal tubes to tracheostomy after a period of 1–2 weeks. 85% of all hospitals monitored intracuff pressure as a routine, and in most intensive care units the cuff was inflated to no‐leak ventilation. The majority of units rarely used muscle relaxants. Phenoperidine and diazepam were the most popular drugs used for the sedation technique. 71.4% of teaching hospitals and 40.9% of non‐teaching hospitals used antacids routinely in patients on intermittent positive pressure respiration. The results are discussed.
Total body oxygen consumption and haemodynamics during the treatment of acute ischaemic heart failure with dopamine and high doses of insulin in dogs
Authors: Reikerås O. , Gunnes R.
Published: January 2009

Acute ischaemic left ventricular failure was induced in closed‐chest anaesthetized dogs by injection of 50 μm plastic microspheres into the left main coronary artery. This effected a 33% decrease in cardiac output. Dopamine and high doses of insulin restored cardiac output, and these agents in combination raised cardiac output to 34% above pre‐ischaemic levels. Total body oxygen consumption was calculated at the various levels of cardiac output, and was found to remain essentially unchanged. Inotropic agents, then, may result in overperfusion with respect to oxygen demand.
Relationship between frequency of ventilation, airways and pulmonary artery pressures, cardiac output and tracheal tube deadspace
Authors: Chakrabarti M. K. , Grounds R. M. , Swenzen G. O. , Whitwam J. G.
Published: January 2009

Intravascular and airway pressures, cardiac output (CO) and blood gas tensions were measured in five adult patients after hepatobiliary surgery. They were ventilated at frequencies of 15, 100 and 200 breaths min‐1 (bpm) with the respiratory fresh gas (RFG) supplied at the proximal and distal end of a Malinkrodt Hi‐Lo tracheal tube. The peak airway pressure (Paw) fell from 1.20 kPa at 15 bpm to 0.6 kPa at 100 bpm, rising again to 1.9 kPa at 200 bpm, and both changes were significant (P<0.05). The mean pulmonary artery pressure (PAMP) remained in the range 1.87–2.00 kPa (14–15 mmHg) at 15 and 100 bpm but rose to over 2.67 kPa (20 mmHg) at 200 bpm (P<0.05). Cardiac output, heart rate and systemic arterial pressure remained unchanged. A small but significant (P<0.05) reduction in Paco2 occurred when the RFG was moved to the distal end of the tracheal tube. A theoretical analysis predicts that the minimal Paw to maintain CO2 homeostasis will occur between 30 to 100 bpm, which is reflected in the results of the present study.
Oral temazepam as a premedicant in elderly general surgical patients
Authors: Salonen M. , Kanto J. , Hovi‐Viander M. , Irjala K. , Viinamäki O.
Published: January 2009

In elderly, general surgical patients, oral temazepam 20 mg given in a soft gelatin capsule proved to be a useful light premedicant when given before spinal anaesthesia. In comparison with placebo, it caused preoperative subjective sedation, prevented an increase in heart rate and decreased serum Cortisol, but not serum antidiuretic hormone levels. However, simple devices (linear analogue scale, Maddox wing test, critical flicker fusion apparatus) appeared to be quite ineffective in differentiating the clinical effects of temazepam from those of placebo. Temazepam given in a soft gelatin capsule to patients in the supine position had a reasonably fast gastrointestinal absorption, but its blood‐lumbar cerebrospinal fluid penetration rate appeared to be quite slow.
Investigation of malignant hyperthermia in Sweden
Authors: Ranklev E. , Fletcher R.
Published: January 2009

One hundred and thirty patients from 52 families were investigated for susceptibility to malignant hyperthermia (MH). The diagnosis of MH susceptibility (MHS) was made by in vitro exposure of muscle to halothane and to caffeine, according to the protocol established by the European malignant hyperpyrexia group. In addition, 13 normal control biopsies were obtained from the same muscle and with the same anaesthesia as in the MH patients. These control results agree with and confirm the criteria formulated in the European MH group. The results are compared with our first 85 investigations performed prior to the establishment of the protocol. The main difference compared to the earlier material is the addition of an equivocal group (MHE), whose muscle reacted in vitro to either halothane or caffeine, but not both. All the families referred because of a fulminant MH reaction contained MHS or MHE members. There was a greater incidence of MH‐negative families, suggesting an increased suspicion of MH amongst the clinicians.
Low‐dose ketamine infusion for analgesia during postoperative ventilator treatment
Authors: Joachimsson P. O. , Hedstrand U. , Eklund A.
Published: January 2009

In a randomized, double‐blind study with placebo, ketamine was used as an analgesic during ventilator treatment in the period of recovery after major abdominal surgery. Forty patients were orally intubated and ventilated by means of a volume‐controlled ventilator. Twenty of them received an i.v. bolus of 30 mg of ketamine followed by an 8‐h infusion of 1 mg per minute. End‐tidal CO2‐concentration was continuously monitored and ventilation was adjusted to metabolic demands prior to assessment of pain. If pain relief was not adequate, the infusion rate was doubled, and if this was still not sufficient, 5 mg injections of ketobemidone were given i.v. If the orotracheal tube was not tolerated, the internal branch of the superior laryngeal nerve was blocked. A total of 30 injections of ketobemidone were administered to 13 control patients, but only five were given to four ketamine patients. Ten control and three ketamine patients required an internal laryngeal nerve block. Dreams and hallucinations were recalled in three patients in the control group and five in the ketamine group. Only one control and two ketamine patients experienced these as unpleasant. In this investigation, ketamine infusion in a low dose appeared to offer satisfactory analgesia and to permit tolerance of the orotracheal tube.
Intensive care of the elderly ‐ a retrospective study
Authors: Grenrot C. , Norberg K. A. , Håkansson S.
Published: January 2009

Access to intensive care is to a large extent a prerequisite of the treatment of increasingly old patients for more and more complicated diseases. The ultimate outcome of such treatment is little known, however. In this study we have followed up 143 patients (91 males and 52 females), aged 70 years or more, who were treated in the intensive care unit (ICU) of Danderyd Hospital for 48 h or more during the years 1979 1982. As a comparison, another group of 143 patients in all age groups treated in the ICU for 48 h or more were studied during 1 year (1980). The main diagnostic groups were infectious diseases, trauma, acute abdominal diseases, malignancy, cardiovascular diseases, and other diseases. The mean mortality within 12 months at age 70 years and above was 52%, highest for cardiovascular diseases (73%) and malignant diseases (60%). Within this age group, the main part of the occupancy in our ICU was held by patients who died within 18 months (58%). The results show that the ICU‐cost per patient per year saved was not much higher for patients in diagnostic groups with higher mortality or longer duration of stay in the ICU than in other groups. Calculations of ICU‐cost seem to be a relevant parameter for the evaluation of the results of ICU care. Fifty per cent of all patients were able to return home some time after intensive care. The humanitarian end result is thus encouraging, but better criteria for selection of patients are needed.
Influence of cigarette smoking on the risk of acid pulmonary aspiration
Authors: Adelhøj B. , Petring O. U. , Frøsig F. , Bigler D. R. , Jensen B. N.
Published: January 2009

Twenty‐five non‐smokers and 35 smokers who had abstained overnight from cigarette smoking and were undergoing minor elective orthopaedic surgery were studied in order to compare gastric volume and pH. There was no significant difference in aspirated volume and pH both just after intubation and prior to extubation between the two groups, thus indicating that habitual smokers undergoing elective surgery in general anaesthesia do not have increased risk of acid pulmonary aspiration compared with non‐smokers.
Continuous measurement of oxygen uptake Evaluation of the Engström metabolic computer and clinical experiences
Authors: Behrendt W. , Weiland Chr. , Kalff J. , Glani G.
Published: January 2009

A new system for continuous measurement of oxygen uptake was tested. The tidal volumes delivered by the system, the accuracy of the oxygen sensor cell, measurement of the oxygen uptake at different inspired oxygen concentrations, and comparative tests of oxygen uptake using the Fick principle were studied. Judging from our results, even thorough maintenance could not entirely prevent leakages. Due to a construction error, there was a large increase in measured oxygen uptake if inspired oxygen concentration was increased. While carbon‐dioxide output was constant, this led to respiratory quotients of less than 0.5. By modifying the system with a mixing chamber for the inspiratory gas, new tubing to the oxygen sensor cell and changes in the computer software, these errors have been corrected in the meantime. In comparative tests of oxygen uptake using the Fick principle (cardiac output and arteriovenous oxygen content difference), we found a mean difference between EMC and the Fick principle of about 6.6% (P≤0.001, r = 0.91) with nearly identical standard deviations for both values. Our experience indicates that the EMC is suitable for continuous measurements of oxygen uptake. Additional technical improvements seem to be possible.
Concentrations of thiopentone in mature breast milk and colostrum following an induction dose
Authors: Andersen L. W. , Qvist T. , Hertz J. , Mogensen F.
Published: January 2009

In two groups of eight patients, concentrations of thiopentone in mature breast milk and colostrum following anaesthesia induction with 5.4 and 5.0 mg kg‐1 b.w. (mean), respectively, were measured in the first 36 h postoperatively. Blood concentrations were measured simultaneously. The maximal concentrations were; in mature breast milk, 3.4 ± 0.68 μmol l‐1 (mean ± s.e. mean) (0.090 mg 100 ml‐1), and in colostrum, 1.3 ± 0.5 μmol l‐1 (0.034 mg 100 ml‐1). The milk/plasma ratio was < 1.0 in both groups. The above concentrations may be regarded as negligible and therefore non‐toxic for the nursing infant.
Evaluation of the usefulness of enzymatic diagnosis of myocardial infarction in patients with acute arterial occlusion of the lower extremities
Authors: Andersen P. T. , Møller‐Petersen J. , Klærke A. , Henneberg E. W.
Published: January 2009

The serum activities of aspartate aminotransferase, lactate dehydrogenase, creatine kinase and estimated creatine kinase isoenzyme MB (CK‐B) were investigated in 12 patients before and after revascularization of ischaemic lower extremities. All patients suffered from sudden lower limb arterial occlusion and underwent embolectomy through a small arteriotomy in the groin. The median serum activity of all four enzymes was elevated before surgery and further increased during the first 24–48 h after revascularization. Median serum activity of aspartate aminotransferase, creatine kinase and lactate dehydrogenase were continuously elevated 7 days after the operation. A high relative CK‐B activity coincided in one patient with the development of electrocardiographic evidence of acute myocardial infarction. It is concluded that any of these four enzymes should be used with caution in the diagnosis of acute myocardial infarction before, during or after operation in patients who have sustained prolonged ischaemia of the lower extremities.
Propofol vs thiopentone as anaesthetic agents for short operative procedures
Authors: Henriksson B.‐Å. , Carlsson P. , Hallén B. , Hägerdal M. , Lundberg D. , Pontén J.
Published: January 2009

In a randomized open study, 120 healthy female patients were included. For short gynaecological procedures they were anaesthetized with either propofol 2.5 mg·kg‐1 (n = 60) or thiopentone 5 mg·kg‐1 (n = 60) in combination with nitrous oxide/oxygen (67%/33%). Supplementary doses of propofol (10–20 mg) or thiopentone (25–50 mg) were given when necessary during the procedure. Induction characteristics for propofol and thiopentone 1 min after start of induction were similar. Propofol seemed to have a more depressant effect than thiopentone on the circulatory response to anaesthesia. Recovery times from the end of the operative procedure until the patients opened their eyes on command and were orientated were shorter in the propofol patients compared to the thiopentone patients. In the propofol group, patients recalled discomfort on injection more often than patients anaesthetized with thiopentone. Otherwise, the side‐effects were similar in both groups. We conclude that propofol is similar to thiopentone in its anaesthetic qualities during induction and maintenance of short anaesthetic procedures. Propofol was associated with a more rapid emergence from anaesthesia than thiopentone.
Intermittent and continuous positive‐pressure ventilation in the prophylaxis of endotoxin‐induced lung insufficiency. A study in pigs
Authors: Borg T. , Modig J.
Published: January 2009

The effects of intermittent and continuous positive‐pressure ventilation (IPPV and CPPV) instituted prophylactically were evaluated in a porcine model of endotoxin‐induced pulmonary and cardiovascular failure. Pigs under ketamine anaesthesia were infused i.v. with E. coli endotoxin over 6 h. Twenty animals, breathing air spontaneously, received endotoxin without treatment. Fifteen animals were treated prophylactically with IPPV (normoventilation with air). Nine animals received prophylactic treatment with CPPV (positive end‐expiratory pressure 0.8 kPa (8 cmH2O)). Endotoxin infusion in spontaneously breathing animals caused profound deterioration of pulmonary gas exchange, a marked rise in pulmonary vascular resistance (PVR) and a moderate increase in extravascular lung water (EVLW). Cardiac output (Qt) and O2 delivery decreased considerably. Metabolic acidosis indicated oxygen deficit. Eleven of 20 animals died during the observation period. IPPV improved arterial oxygenation during endotoxin infusion, and the increase in EVLW tended to be lower. The alterations in pulmonary haemodynamics, Qt and O2 delivery, were of the same magnitude as in spontaneously breathing animals. Survival was improved. CPPV fully prevented the deterioration in pulmonary gas exchange and the development of pulmonary oedema. There was an accentuated increase in PVR. Qt and Os delivery decreased markedly and a severe metabolic acidosis developed. All animals treated with CPPV died during the observation period. These results indicate that prophylactic IPPV and CPPV may counteract the development of sepsis‐induced lung insufficiency in man. However, it must be emphasized that adequate cardiovascular support is essential in optimizing the treatment.
Heating efficacy of external heat supply during and after open‐heart surgery with hypothermia
Authors: Joachimsson P.‐O. , Nyström S.‐O. , Tydén H.
Published: January 2009

Heat balance after cardiac surgery with hypothermic cardiopulmonary bypass (CPB) was studied in 156 patients. In spite of rewarming during CPB there was residual hypothermia at the end of operation. This heat deficit could not be prevented by intraoperative use of a heating mattress at 38°C and/or heated (39°C) humidified inspired gases. Postoperatively, in four groups of patients, the core and finger skin temperatures were recorded and the mean skin and mean body temperatures and heat balance were calculated. Heating of humidified inspired gases (n = 22) gave little improvement in the time course of the temperatures and heat balance as compared with that in a control group with no external warming postoperatively (n = 49). A thermal ceiling (a low‐temperature radiator suspended above the bed and providing radiant heat (n = 35)) significantly increased the measured temperatures, which were restored to normal earlier than those in the controls. Also, with this radiant heat postoperative shivering was almost abolished. With a combination of radiant heat and heated, humidified gases (n = 50), the postoperative heat balance was improved somewhat further. For patients treated with radiant heat, postoperative rewarming was accomplished in a shorter time and almost without active endogenous muscular thermogenesis, as was evident by the great reduction in postoperative shivering.
Circulatory effects of short‐term hypercapnia during high thoracic epidural anaesthesia in elderly patients
Authors: Sundberg A. , Wattwil M.
Published: January 2009

Circulatory changes and the degree of sympathetic block were evaluated in 15 elderly patients with high thoracic epidural anaesthesia (T1‐T5). Bupivacaine 5–6 ml 0.5% was injected via an epidural catheter at the T3‐level. The quality of the sympathetic block was determined with the Valsalva manoeuvre. Induced hypercapnia was used to quantify the degree of sympathetic block. Following thoracic epidural anaesthesia (TEA), cardiac output, stroke volume and arterial blood pressure decreased. During hypercapnia, heart rate and arterial blood pressure increased both before and after established TEA. Thus the block of the sympathetic innervation to the heart with a high TEA using 0.5% bupivacaine was not sufficient to prevent mobilization of circulatory reserves during sympathetic stimulation. The most likely explanation is considered to be the lack of neural block of the efferent nerves leading to the adrenal medulla and the peripheral vascular bed.
Evaluation of epidural needles
Authors: Kumar B. , Messahel F. M.
Published: January 2009

Eight different epidural needles (Tuohy Everett, Pitkin, Braun Perifix and Portex in 16‐gauge, and Becton Dickinson Crawford, Becton Dickinson B‐D, Monoject and Portex in 18‐gauge) were evaluated using a scanning electron microscope and spectral x‐ray analysis. Differences were noted in the metal composition, between disposable and reusable needles with respect to molybdenum content. The inner surface of the 18‐gauge Crawford needle was found to be the smoothest and it also had the best clearance between the needle and stilette. The Portex 16‐gauge had the best needle/stilette fit at its bevel. The hardness of the metal was found to be satisfactory in all the needles.
Pressure characteristics of the Ambu CPAP system and the Servo Ventilator 900C in CPAP mode
Authors: Zetterström H. , Jonsson L. O.
Published: January 2009

Spontaneous breathing was simulated in the Ambu continuous positive airway pressure (CPAP) system and the Servo ventilator 900C by means of a lung model programmed to mimic the respiratory flow patterns of a healthy volunteer and a patient in severe respiratory distress. Changes in airway pressure, flow and volume were recorded during “breathing” with CPAP at 0.5, 1.0 and 1.5 kPa. In the Ambu system, the airway‐pressure decreased during inspiration and increased during expiration, while the mean airway pressure was close to the pre‐set CPAP value. The pressure changes were minimal when the fresh gas flow was increased from 15 to 25 l·min‐1. The higher fresh gas (low is recommendable during deep or rapid breathing. In the Servo Ventilator 900C, there was a short initial inspiratory pressure drop, succeeded by a pressure rise above the CPAP value. The expiratory airway pressure was somewhat higher than CPAP. Both systems were found to be recommendable for clinical use.
Effect of spinal versus epidural anaesthesia with 0.5% bupivacaine on lower limb blood flow
Authors: Perhoniemi V. , Linko K.
Published: January 2009

Changes in the haemodynamics of the lower extremities, big toe temperature, blood pressure and heart rate were studied in 20 patients undergoing spinal or epidural anaesthesia for transurethral surgery. Calf blood flow was determined by strain gauge plethysmography (SGP) and Doppler ultrasound. Bupivacaine 0.5% was injected at the L3‐L4 interspace, the dose being 3–4 ml (mean 3.6) in the spinal and 17–20 ml (mean 18.6) in the epidural group. The number of sensory blocked segments 30 min after anaesthesia was 12.7 ± 0.7 (mean ± s. e. mean) and 14.4 ± 0.7. respectively. Only minor decreases in blood pressure were noted following the blocks. Heart rate remained virtually unchanged. The increase in skin temperature was more pronounced (P<0.01) following epidural (mean 8°C) than spinal anaesthesia (mean 4°C). In addition, the arterial blood flow was significantly higher (P<0.05) following epidural than spinal block (means 3.5 and 2.2 ml/100 ml/ min, respectively). The venous capacity and maximum venous outflow remained pr unchanged in both groups. Obviously, epidural anaesthesia with bupivacaine causes a more intensive sympathetic block than does spinal anaesthesia. As probably no venous pooling occurred, when examined by SGP and Doppler ultrasound, neither of the blocks is likely to contribute to the initiation of deep vein thrombosis.
Elevations of neuropeptide Y‐like immunoreactivity and catecholamines in plasma on increased intracranial pressure in the pig
Authors: Rudehill A. , Lundberg J. M. , Sollevi A. , Hjemdahl P.
Published: January 2009

Graded increases of intracranial pressure (ICP) in anaesthetized pigs induced elevations of plasma levels of neuropeptide Y (NPY)‐like immunoreactivity (LI) and catecholamines, simultaneously with hypertension and tachycardia. Plasma adrenaline (ADR) increased at a lower ICP‐level than did the plasma levels of noradrenaline (NA) and NPY‐LI. At the maximal ICP elevation, 22.9 kPa (172 mmHg), plasma NPY‐LI was increased about 10‐fold, from 48±8 pmol/l in the basal state, while NA and ADR concentration increased more than 100‐fold. At this maximal ICP‐level the plasma levels of NPY‐LI were correlated to the concentrations of both NA (r = 0.87, P<0.01) and ADR (r = 0.92, P <0.001). Plasma NPY‐LI continued to increase to about 1000 pmol/l, 10 min after the maximal elevation of ICP was discontinued, while the catecholamines then had declined considerably. A slight cardiac release of NPY‐LI was observed at the maximal elevation of ICI. The half‐life of NPY‐LI in plasma was about 6 min upon systemic infusion. At plasma levels similar to those obtained upon maximal ICP elevation, exogenous NPY caused slight vasoconstriction in the spleen and skeletal muscle, but had no effects on coronary blood flow or systemic blood pressure. This suggests that NPY mainly exerts local actions after release from nerve endings, while levels of circulating NPY in plasma must be very high to influence blood flow in some organs. It is concluded that elevation of ICP results in hypertension and tachycardia related to elevated plasma levels of NPY‐LI and catecholamines. The markedly increased plasma levels of NPY‐LI suggest that this peptide is co‐released with NA from sympathetic nerve terminals. NPY may therefore contribute to the cardiovascular response to elevation of ICP.
Haemodynamic effects of intravenous bupivacaine during high thoracic epidural anaesthesia
Authors: Sundberg A. , Wattwil M. , Wiklund L.
Published: January 2009

Administration of small doses of bupivacaine epidurally at the upper thoracic level will partially block the cardiac sympathetic nerves hut not the sympathetic outflow via the adrenals. Local anaesthetics have direct systemic effects on the myocardium and the systemic circulation. The present study aimed to examine the effect of high thoracic epidural anaesthesia (TEA) in elderly patients, and to examine the effect (if raising plasma bupivacaine concentrations in these patients, who had earlier had the sympathetic innervation of the heart blocked by thoracic epidural anaesthesia. Fifteen elderly patients scheduled for thoracotomy took part in the study. All received high thoracic epidural anaesthesia including the upper five thoracic dermatomes. When epidural block WBS established, ten patients received bupivacaine 3 mg/min intravenously for 20 min, while five patients received a corresponding volume of normal saline solution. After TEA was established, heart rate, mean arterial blood pressure and cardiac output decreased. When bupivacaine was given to these patients intravenously during the block, mean arterial blood pressure increased, while cardiac output decreased still more. The mechanisms behind these effects seem to be a direct constriction of the systemic blood vessels and a depressive effect on the myocardium, which was blocked from the influence of the cardiac sympathetic nerves by the high thoracic epidural block.
Recovery from sufentanil anaesthesia for outpatient arthroscopy: a comparison with isoflurane
Authors: Zuurmond W. W. A. , Leeuwen L. Van
Published: January 2009

This study compares the recovery from sufentanil and isoflurane anaesthesia in patients undergoing outpatient arthroscopy of the knee under general anaesthesia. In 40 unpremedicated patients, divided at random into two groups, anaesthesia was induced with methohexitone and vecuronium bromide and, after intubation, maintained with nitrous oxide 66% in oxygen supplemented with sufentanil or isoflurane. Patients in Group A received sufentanil (I μg/kg) at induction and if necessary an incremental dose of 10 μg. Patients in Group B received 3%, isoflurane prior to intubation and 0.9% during maintenance. Awakening from anaesthesia was more rapid with sufentanil than isoflurane. Recovery was assessed from the time patients took to open their eyes, to give correct answers to five questions and to recover from ocular imbalance (Maddox wing test), and by comparing pre‐ and postoperative performance of a paper and pencil test (the p‐deletion test). After 2 h, there was no difference between the two groups. Both anaesthetic techniques provided satisfactory operating conditions, but the sufentanil group showed a higher incidence of nausea and vomiting (45%) than the isoflurane group (15%).
The influence of epidural analgesia on the splanchnic exchange of amino acids during upper abdominal surgery
Authors: Lund J. , Sandin R. , Stjernström H. , Vinnars E. , Jorfeldt L. , Wiklund L.
Published: January 2009

Splanchnic turnover of plasma amino acids was studied in 10 patients given thoracic epidural analgesia combined with general anaesthesia for elective cholecystectomy. Ten other patients given only general anaesthesia for cholecystectomy served as a control group. All patients received an infusion of glucose during the investigation. The total concentration of amino acids in arterial plasma did not change in the patients given epidural analgesia but decreased by approximately 15% in the non‐epidural group. In both groups splanchnic uptake of amino acids increased during surgery and was found to be more than doubled in the early postoperative period. The addition of epidural analgesia to general anaesthesia did not modify the splanchnic uptake or amino acids during surgery and in the immediate (2 h) postoperative period.
Influence of the respiratory flow pattern on rebreathing in Mapleson A and D circuits
Authors: Jonsson L. O. , Zetterström H.
Published: January 2009

In a lung model the rebreathing effects of different respiratory flow patterns (RFP) were studied in the coaxial Mapleson A (Lack) and D (Bain, Coax‐II) systems during spontaneous breathing. In the Mapleson A system RFP was not found to have any impact. In the D systems FACO2 was higher with an RFP typical of halothane‐anaesthetized patients than with an KFP with an exponentially decreasing expiratory flow and an end‐expiratory flow pause (FTEP). The difference in FACO2 was 26% with a ·F corresponding to 100 ml · min‐1 · kg‐1 body weight. The RFP in a non‐anaesthetized volunteer was intermediate between these two patterns. Rebreathing decreased in the D systems with prolongation of FTEP and when a decelerating expiratory flow was used.
Rebreathing and ventilatory response to different fresh gas flows in the Bain and Lack systems. A clinical study
Authors: Jonsson L. O. , Johansson S. L. G. , Zetterström H.
Published: January 2009

Thirty‐four adults were studied during halothane anaesthesia with spontaneous breathing, while undergoing orthopaedic surgery. They were randomly divided into two groups according to whether the Bain (n = 18) or the Lack (n = 16) system was used. Respiratory flows were recorded and arterial blood gases drawn at different fresh gas flows (·F). The values obtained were compared with those recorded under non‐rebreathing conditions (NRC). In the Bain system the proportion of rebreathers was 0.22, 0.25. 0.55 and 0.83 when the ·F was 175, 150, 125 and 100 ml · min‐1 · kg‐1 body weight (b.w.), respectively. In the Lack system these proportions were 0.43. 0.55 and 0.92 at ·F of 85, 70 and 55 ml · min‐1 kg‐1 b.w., respectively. The ventilatory response to rebreathing was an increase in minute ventilation (·E), keeping the partial pressure of arterial carbon dioxide (Paco2) almost unaltered. In the Bain system the ·E · kg‐1 · b.w. thus increased by 18% and 38% at ·F of 125 and 100 ml · min‐1 kg‐1 b.w., respectively, when compared to NRC (P < 0.05). The corresponding increases in the Lack system were 15% and 37% at ·F of 70 and 55 ml · min‐1 · kg‐1 b.w., respectively (P < 0.01). In the Lack group also the Paco2 increased by 6% when a ·F of 55 ml ·min‐1 · kg‐1 b.w. was used compared to the value obtained under NRC (P<0.05). The respiratory flow pattern was similar in both groups and at all studied ·F levels, despite a small, insignificant, decrease in expiratory flows when high ·F was given in the Bain system. The conclusion is that ·F of 150 ml · min·kg‐1 b.w. in the Bain system and 85 ml·min‐1 · kg‐1 b.w. in the Lack system should be used.
Plasma clearance of fat emulsion during continuous heparin infusion
Authors: Persson E. , Nordenström J. , Vinnars E.
Published: January 2009

Intravenous fat tolerance was tested in two groups of patients given a continuous i.v. infusion of heparin for several days. One group of 11 patients with deep vein thrombosis (DVT) of the leg was given 25000 30000 IU heparin daily for 4–5 days. The other group comprised 10 patients who had central venous catheters (CVC) for total parenteral nutrition. These patients were given 20000 IU heparin daily for 6 days as prophylasix against CVC‐related thrombosis. In the DVT group heparinization was associated with a 44% decrease in plasma fat removal capacity (P<0.05). This reduction persisted for 2 days after the discontinuation of heparin therapy. In the CVC group the plasma fat removal capacity decreased by 29% during heparinization (P >0.05, NS). During heparinization activated partial thromboplastin time was more than three times the basal value in the DVT group but less than twice those in the CVC group. One week after the heparin therapy the serum triglyceride levels were higher in both groups compared with initial values (DVT group: 1.2 ± 0.2 s.c. mean vs. 1.7 ± 0.3 mmol/l; P < 0.05. CVC group: 1.0 ± 0.1 vs. 1.4 ± 0.2 mmol/l; NS). The possibility that full‐dose heparinization reduces plasma fat removal capacity and that this may be due to a partial depletion of lipoprotein lipase stores is discussed.
Labetalol as a hypotensive agent for middle ear microsurgery
Authors: Saarnivaara L. , Klemola U.‐M. , Lindgren L.
Published: January 2009

Labetalol, an α‐ and β‐adrenergic receptor‐blocking agent, was studied as a hypotensive agent during halothane (mostly 0.5 vol.%)‐N2O‐fentanyl‐d‐tuhocurarine anaesthesia with a head‐up tilt of 5 degrees in 41 patients undergoing middle ear microsurgery. After the mean initial dose of 0.3 mg/kg, the mean need for labetalol ranged from 0.05 to 0.07 mg/kg at 30 ± 5‐min intervals. The mean duration of the hypotensive period was 102 min. During the hypotension, the average mean arterial pressure ranged from 59 to 62 mmHg (7.9‐8.3 kPa) and the mean heart rate from 61 to 66 b.p.m. After labetalol the maximum cardiac output decrease was 7%. Before labetalol the mean Pao2 value was 158 mmHg (21.1 kPa) and during hypotension it ranged from 145 to 149 mmHg (19.3–19.9 kPa) when Fio2 was 40%. The only peroperative side effects were ECG changes (middle junctional rhythm and sinus bradycardia) which occurred in 10% of the patients. The mean value for the degree of haemostasis rated by the otologist on a visual analogue scale between poor (0 mm) and excellent (100 mm) was 91 mm. The patients were able to open their eyes and to give their names 8–9 min after the end of anaesthesia. After extubation the patients were normotensive and there were no clinically significant changes in the cardiovascular parameters during the 4‐h recovery room period. Acid‐base status showed slight metabolic acidosis. The most common postoperative side effects were nausea only and nausea + vomiting, which occurred in 39% and 20% of the patients, respectively. It is concluded that labetalol produced stable, easily controllable hypotension without a compensatory rise in the heart rate, with minimal effect on peroperative Pao2 value or cardiac output, as well as good operating conditions. The postoperative course was uneventful with the exception of a high incidence of nausea and vomiting, most probably due to the operation rather than to the anaesthesia.
Elimination of and heart rate response to atropine in the elderly are independent of sex
Authors: Kanto J. , Pihlajamäki K. , Hovi‐Viander M.
Published: January 2009

Sex‐related changes in the pharmacokinetics and pharmacodynamics (heart rate) of atropine were studied in female (n = 9) and male (n = 9) elderly patients after a single 0.02 mg/kg i.v. injection of the drug at the beginning of a combination anaesthesia. No significant differences were found between the sexes, which indicates that there are no sex‐related alterations in the response to this anticholinergic agent.