bluuebunny/crossref_metadata_2025 huggingface dataset:
Gas Exchange and Respiratory Mechanics During Hip Arthroplasty
Authors: Mebius C. , Hedenstierna G.
Published: January 2009

Gas exchange and respiratory mechanics were studied during hip arthroplasty, according to Charnley (1961). Dead space measurements were made by capnography and thoracic compliance and resistance, calculated liom tracheal pressure variations and respiratory gas flow. PaO2 fell by 2.5 kPa with the insertion of each prosthesis. Small increases in PaO2 were also seen. Distal (approximately corresponding to alveolar) dead space increased by 25% when each prosthesis was anchored. Dynamic thoracic compliance fell by 30–40 ml/kPa at the insertion of either prosthesis, while inspiratory and expiratory resistances were unaffected. The findings may indicate interference with the functions of both the bronchial and the pulmonary vascular tree.
Nitrous Oxide and the Baroreceptor Reflexes in the Dog
Authors: Bagshaw R. J. , Cox R. H.
Published: January 2009

The effects were studied of 67 % nitrous oxide on the baroreceptor control of systemic haemodynamics in the dog. Nitrous oxide was added to end‐tidal halothane concentrations of about 0.9% (H2) together with halothane levels approximately 25 % above (H3) and below (H1) the H2 concentration. Baroreceptor function was assessed by brachiocephalic artery occlusion (BCO) or perfusion of the isolated carotid sinuses. In the intact animal, nitrous oxide significantly increased mean arterial pressure only at the H2 level (P<0.001). At the closed loop operating point of the carotid sinus reflex (CSR), for all halothane levels, nitrous oxide decreased cardiar output and stroke volume, increased systemic vascuIar resistance and central venous pressure with no effect upon mran arterial pressure. The operating point gain of the CSR was significantly depressed by nitrous oxide at the H1 and H3 levels (P<0.05). The Csroperating characteristics were significantly modified by N2O in a manner which depended upon the underlying concentration of halothane.
Pentoxifylline in Regional Cerebral Ischemia in Cats
Authors: Steen P. A. , Milde J. H. , Michenfelder J. D.
Published: January 2009

The effect of pentoxifylline on regional cerebral ischemia was evaluated in 22 cats. In one group of 10 cats the middle cerebral artery (MCA) was occluded by a transorbital approach, and the cats were maintained on an intensive care protocol for 48 h. Pentoxifylline 10 mg · kg‐1 initiated intravenously 30 niin post‐occlusion and followed by 6.3 mg · kg‐1 · h‐1 for 48 h failed to improve the neurologic outcome or infarct size when compared to controls. In another group of 12 cats with the same ischemic lesion, regional cerebral blood flow in the anterior (ischemic) area and an ipsilateral parieto‐occipital region was measured by 133Xe wash‐out after intra‐arterial injection. MCA occlusion reduced the anterior flow by 50% from a mean control value of 62.7 ml · 100 g‐1 · min‐1 to 31.9 ml · 100 g‐1 · min‐1. The parieto‐occipital flow was reduced by 20–30%, probably due to diaschisis. Pentoxifylline produced only a brief, although approximately 50%, increase in flow detected over both brain regions and failed to improve the cerebral energy stores as measured 150 min following MCA occlusion. From the neurologic, blood flow and metabolic data, it is concluded that pentoxifylline failed to affect cerebral ischemia favorably in cats.
Enflurane Improves the Oxygen Supply /Demand Balance in the Acutely Ischaemic Canine Myocardium
Authors: Smith G. , Evans D. H. , Ashek M. J. , Bentley S.
Published: January 2009

Acute myocardial ischaemia was produced in six dogs by ligation of the anterior descending branch of the left main coronary artery. Enflurane 1.5% inspired produced a significantly smaller reduction in blood flow in the ischaemic than in the non‐ischaemic area in myocardium in the presence of a 46% reduction in mean arterial pressure. The improvement in oxygen availability/consumption ratio in the ischaemic in Comparison with non‐ischaemic areas was attributed to a 16% reduction in heart rate.
Halothane Anaesthesia with Spontaneous Respiration for Tonsillectomy in Children
Authors: Valentin N. , Lomholt B. , Thorup M.
Published: January 2009

Bain's anaesthetic circuit was used in 22 children undergoing tonsillectomy under halothane anaesthesia with spontaneous respiration. End‐tidal CO2 was monitored by capnography. The median maximum end‐tidal CO2 was 7%, and during surgery nine patients had an end‐tidal CO2 higher than 7%, corresponding to a Paco2 close to 8 kPa when the arterial to end‐tidal CO2 difference is taken into consideration. Increase in fresh gas flow or change to a non‐rebreathing system had virtually no effect on end‐tidal CO2. However, following discontinuation of halothane or during controlled respiration, acceptable values of end‐tidal CO2 were reached, leading to the conclusion that respiratory depression was responsible for the high values of end‐tidal CO2 rather than properties of Bain's circuit or too low gas flow rates.
Effect of Posttraumatic Epidural Analgesia on the Cortisol and Hyperglycaemic Response to Surgery
Authors: Møller I. W. , Rem J. , Brandt M. R. , Kehlet H.
Published: January 2009

Plasma cortisol and glucose were measured in 36 patients undergoing abdominal hysterectomy under either general anaesthesia with halothane (Group I), epidural analgesia (T4‐S4) effective before surgery (Group II) or general anaesthesia plus epidural analgesia (T4‐S4) effective from 30 min after initiation of surgery. The results confirmed that epidural analgesia effective before skin incision (Group II) prevented the normal per‐and postoperative increase in plasma cortisol and glucose. Patients receiving posttraumatic epidural analgesia (Group III) showed the normal initial increase in plasma cortisol and glucose, but initiation of epidural analgesia immediately broke the stress‐response and prevented any further increase in plasma cortisol and glucose. However, although posttraumatic neurogenic blockade inhibited a major part of the stress‐response, resting endocrine‐metabolic activity was not reestablished. suggesting that once released the endocrine‐metabolic response to trauma leads to persistent changes even if further afferent stimuli from the traumatized area are prevented.
Influence of Epidural Morphine on Postoperative Pain, Endocrine‐Metabolic, and Renal Responses to Surgery. A Controlled Study
Authors: Jørgensen B. C. , Andersen H. B. , Engquist A.
Published: January 2009

In order to assess the analgesic properties of epidural low‐dose morphine and its possible influence on thr adrenocortical, hyperglycemic, renal, electrolyte and leukocyte responses to surgery and nitrogen excretion, a double‐blind randomized study was undertaken in 14 otherwise healthy patients admitted lor hysterectomy under halothane, N2O/O2 anesthesia. Before induction of anesthesia, an epidural catheter was introduced into the lumbar epidural space. After induction of anesthesia, either morphine 4 mg in 10 ml saline or 10 ml saline was injected into the epidural space, according to the allocation. Postoperatively, the degree of pain was evaluated by means of a visual analogue scale (0–10). When pain score exceeded 5 points during the 24‐h trial, either 4 mg morphine in saline or saline was given epidurally. If the pain score did not decrease more than 2 points after an epidural injection, morphine was given parenterally (5 mg i.v. f 5 mg i.m.). The results showed that pain scores, duration of pain relief and doses of morphine differed significantly between groups (P<0.05). Plasma concentrations of cortisol and glucose, plasma‐ and urine electrolytes, 24‐h creatinine and free‐water clearances, diuresis, fluid balance, leukocyte count and nitrogen excretion differed insignificantly between groups.

In conclusion, epidural low‐dose morphine is a superior alternative to conventional postoperative pain treatment because of greater and longer lasting pain relief, without apparent side‐effects. The measured endocrine‐metabolic and renal responses did not differ between groups, indicating that low‐dose epidural morphine does not inhibit afferent neurogenic stimuli from the site of surgical trauma.
Epidural Met‐Enkephalin (FK 33–824). A Dose‐Effect Study
Authors: Andersen H. B. , Jørgensen B. C. , Engquist A.
Published: January 2009

The present study examines the analgesic effect on postoperative pain of 0.001‐0.5 mg of epidural FK 33–824. a synthetic met‐enkephalin analogue. The results showed that FK 33–824 diluted in 10 ml of isotonic aalinr induced analgesia in doses of 0.02, 0.05, 0.1, 0.2, and 0.5 mg. The analgesic effect, however, was inferior to that of epidural morphine (4 mg in 10 ml isotonic saline), since analgesia was unpredictable and clinically insufficient in four out of eight patients receiving 0.02‐0.5 rng. Additionally, the duration of action was shorter for FK 33–824 than for morphine.
The Artificially Ventilated Preterm Rabbit Neonate as Experimental Model of Hyaline Membrane Disease
Authors: Nilsson R.
Published: January 2009

Bronchiolar epithelial lesions, similar to those in human hyaline membrane disease (HMD), can be induced by artificial ventilation of newborn rabbits, delivered on day 27 of gestation. As verified by electron microscopy, these epithelial lesions develop within only 1–5 min of artificial ventilation. Tracheal instillation of natural surfactant at birth improves lung‐thorax compliance in these animals, enhances the aeration of the alveolar compartment. and prevents the development of bronchiolar epithelial lesions. This prophylactic effect is obtained even when the compliant lungs of the surfactant‐treated animals are greatly overventilated, i.e. when the ventilator is set at standardized high insufflation pressure. The application of a low positive end‐expiratory pressure (5 cmH2O) also results in increased lung‐thorax compliance, and reduces the extent of bronchiolar epithelial lesions. These findings suggest that the epithelial lesions are secondary to an abnormal expansion pattern. In a premature neonate with surfactant deficiency, overdistension of airways and irregular aeration of the alveolar compartment might produce shear stress in the airway mucosa, leading to disruption of the epithelium and formation of hyaline membranes. The same mechanism is probably also involved in the pathogenesis of the epithelial lesions in human neonatal HMD.
Smooth Muscle Effects of Lidocaine, Prilocaine, Bupivacaine and Etidocaine on the Human Umbilical Artery
Authors: Tuvemo T. , WilldeckLund G.
Published: January 2009

The smooth muscle effects on human umbilical arteries of four different local anaesthetic agents‐lidocaine. etidocaine, prilocaine and bupivacaine‐were studied. Lidocaine and etidocaine relaxed the arteries. etidocaine more profoundly than lidocaine. Prilocaine in the concentration range 10‐1,000 μg/ml caused pronounced contractions. Bupivacaine consistently evoked a contractile response in the concentration range 5–25 pg/ml. but at lower and higher concentrations the response to this drug was inconsistent. The concentrations of lidocaine were determined in six human umbilical arteries following maternal epidural block with this agent and were found to be 0.1‐1.7 μg/g tissue. The contractile actions of prilocaine and bupivacaine on the human umbilical arteries are undesirable and might be hazardous if high concentrations are attained, e.g. during paracervical block.
Oleic Acid Lung Damage in Pigs
Authors: Haldén E. , Hedstrand U. , Torsner K.
Published: January 2009

With the purpose of producing a lung damage model simulating post‐traumatic pulmonary insufficiency, oleic acid 0.1 ml‐1 kg‐1 body weight (b. w.) was infused intravenously into eight mechanically ventilated young pigs, and the effects were studied for 2 h. After the infusion, Pao2 during air breathing decreased to a fairly low and stable level of about 7 kPa. Venous admixture during air breathing and Vd/Vt showed a marked initial increase and then remained unchanged, while venous admixture during breathing of pure oxygen increased but less markedly. Haematocrit (EvF), arterial carbon dioxide tension (Paco2) and base excess (BE) were unchanged. Mean pulmonary arterial pressure more than doubled and cardiac output decreased by 1/3, which was considered to reflect an insuperable increase in the resistance of the pulmonary blood flow. The lung model was found to resemble post‐traumatic pulmonary insufficiency with respect both to the V/Q ratio displacement and to the macroscopic appearance of the lungs at autopsy.
Effects of Thiopentone on the Canine Coronary Circulation in Acute Experimental Myocardial Ischaemia
Authors: Smith G. , Thorburn J. T. , Rogers K.
Published: January 2009

Acute myocardial ischaemia was induced in five greyhounds by ligation of the anterior descending branch of the left main coronary artery. Changes in oxygen availability and consumption in the ischaemic area in response to thiopentone 10 mg kg‐1 were compared with corresponding changes in non‐ischaemic myocardium supplied by the circumflex artery. Despite a 40% reduction in arterial pressure, there were no significant changes in the oxygen availability/consumption ratio in either normal or ischaemic areas.
Bradycardia with Laryngeal Spraying in Children
Authors: Mirakhur R. K.
Published: January 2009

Significant and clinically important bradycardia has been observed on spraying the larynx in children irrespective of routine intramuscular administration of anticholinergic drugs. Intravenously administered anticholinergics, particularly glycopyrrolate (7.5 μg kg‐1), are more effective. It is, however, suggested that spraying the larynx may be avoided altogether in children.
Effects of Halothane on Coronary Haemodynamics and Myocardial Metabolism in Patients with Ischaemic Heart Disease and Heart Failure
Authors: Reiz S. , Bålfors E. , Gustavsson B. , Häggmark S. , Nath S. , Rydvall A. , Truedsson H.
Published: January 2009

Halothane was administered at an end‐tidal concentration of 1% to 10 patients with stable ischaemic heart disease and clinical and haemodynamic signs of moderate heart failure. Measurements of central haemodynamic variables, coronary sinus blood flow and oxygen, lactate and hypoxanthine balances over the myocardium were done before and at steady state during halothane anaesthesia. Halothane induced marked haemodynamic changes with decreases in mean arterial pressure; (‐43%), mean pulmonary arteriolar occlusion pressure (‐42%), systemic vascular resistance (‐31%), cardiac index (‐20%), stroke volume index (‐31%) and left and right stroke work indices (‐62% and ‐55%, respectively). Heart rate and pulmonary vascular resistance did not change. Coronary sinus blood flow decreased in parallel with perfusion pressure, and myocardial oxygen consumption decreased (‐40%), as did myocardial oxygen extraction. Rate pressure product and triple product correlated better with changes in myocardial oxygen consumption in the present subset of patients than in healthy volunteers during halothane anaesthesia. The findings suggest that halothane, through its systemic vasodilatory effect, unloads the failing left ventricle and that this peripheral action predominates over the direct cardiodepressant action of the agent. The combined findings of unchanged coronary vascular resistance, decreased myocardial oxygen extraction and absence of increasing or pathological levels of lactate and hypoxanthine in coronary sinus blood imply a direct dilatory effect of halothane on the coronary vasculature.
Midazolam Compared with Thiopentone as an Induction Agent
Authors: Pakkanen A. , Kanto J.
Published: January 2009

In patients premedicated with scopolamine + morphine (+ 5 mg nitrazepam the evening before surgery), the sleep‐inducing effect of midazolam 0.15 mg/kg l. v. was clearly slower in onset than that of thiopentone 4.67 mg/kg‐1. v. Somewhat fewer cardiovascular and local sequelae were found in the midazolam group, but, although apnoea occurred less often in the midazolam group it lasted longer. On the whole, the differences between midazolam and thiopentone had no apparent clinical consequences. Midazolam is a new alternative agent for induction in combination anaesthesia.
Advantages of Glycopyrrolate over Atropine during Reversal of Pancuronium Block
Authors: Heinonen J. , Salmenperä M. , Takkunen O.
Published: January 2009

Atropine 0.015 mg kg‐1 and glycopyrrolate 0.0075 mg kg‐1 were compared as antimuscarinic agents during reversal of pancuronium block with neostigmine 0.03 mg kg‐1 in 30 patients anaesthetized with thiopental—N2O‐fentanyl and undergoing minor surgery. The decrease of heart rate was more pronounced in patients who received atropine‐neostigmine. The mean of the lowest heart rate was 44.3 beats min‐1 in the atropine group compared with 54.3 beats min‐1 in the glycopyrrolate group. Five patients treated with atropine‐neostigmine developed a transient nodal rhythm as compared with two of those receiving glycopyrrolate‐neostigmine (non‐significant difference). Recovery from anaesthesia, as assessed by the awakening after the discontinuation of N2O administration, was more rapid in patients given glycopyrrolate. In conclusion, glycopyrrolate seems to have advantages over atropine when used during reversal of pancuronium block with neostigmine.
A Clinical Neuropsychological Study of the Postoperative Course after Three Types of Anaesthesia
Authors: Elsass P. , Stibolt O. , Klauber P. v. , Christensen S.‐E. , Lunding M.
Published: January 2009

In a double‐blind study, 57 patients were anaesthetized with either Althesin®, thiopentone, or fentanyl combined with diazepam for cystoscopies. One and a half and four hours after the administration of anaesthesia, the patients were investigated with an objective neuropsychological method, Continuous Reaction Time, and with a subjective rating scale, Beecher's Mood Scale. One week later the patients answered a questionnaire about side‐effects experienced during the days following anaesthesia. At the 1 1/2 h investigation, the patients were cerebrally affected, both subjectively and objectively. The CNS‐dysfunction was different for the three anaesthetics. After administration of thiopentone, the patients experienced the highest degree of subjective effects but had the smallest reaction time prolongation. Fentanyl‐diazepam gave the least subjective effects, but the highest degree of cerebral affection in the reaction time measurements. The effects of Althesin were intermediate. Four hours after anaesthesia, the reaction time prolongations had disappeared, except for Althesin, and only patients who had thiopentone registered subjective effects. The number of side‐effects was greatest and most prolonged following thiopentone. About 25% of the patients reported that side‐effects had persisted more than 1 day after anaesthesia.
Atropine before Enflurane Anaesthesia: Effects on Cardiac Rhythm, Pulse Rate, Blood Pressure and Airway Secretion
Authors: Valentin N. , Lomholt B. S. , Andersen G. w.
Published: January 2009

The occurence of cardiac arrhythmias and changes in pulse rate and blood pressure during mask anaesthesia, with enflurane was investigated in 92 patients with special reference to the influence of atropine ((1.01 mg kg‐1 5 min before anaesthesia) and thiopental. The average duration of anaesthesia was a little less than 1 h in all four groups. More than five ventricular extrasystoles occurred in one patient (38 min after atropine). Supra ventricular (mainly nodal) arrhythmias were significantly (P < 0.005) more common in the atropine groups (15/45) than in the non‐atropine groups (4/47). Following atropine, heart rate increased by about 25 beats min‐1, whereas only very slight increases were seen in the non‐atropine groups. Blood pressure fell at the induction but was almost back to normal at the end of anaesthesia. Blood pressure was unaffected by atropine. Slightly lower values of blood pressure were suggested in the thiopental groups, whereas thiopental did not modify cardiac rhythm or pulse rate. Suction of the pharynx was necessary in only one patient. In conclusion, the present study does not support the routine administration of atropine before enflurane anaesthesia with or without thiopental induction.
Cerebral Blood Flow and Oxygen Uptake in Endotoxic Shock. An Experimental Study in Dogs
Authors: EkströmJodai B. , Häggendai E. , LarssonM.D. L. E.
Published: January 2009

Cerebral blood flow (CBF), cerebral oxygen uptake (CMRo2) and central haemodynamics in anaesthetized dogs with controlled ventilation were studied at intervals for 2 h following an intravenous injection of E. coli endotoxin, 1.0–1.5 mg/kg. CBF showed a 30% decrease within 15 min after the endotoxin administration, while the arterial blood pressure was still not markedly depressed. Autoregulation to arterial blood pressure changes was maintained during endotoxinaemia and the cerebrovascular reaction to changes in arterial carbon dioxide tension (Paco2) depressed. Normocapnic animals (PacO2 ≥ 4.0 kPa) showed an increase in CMRO2 of over 40%, that was obvious 1 h after the administration of endotoxin. The intracranial pressure was decreased within 5 min of the administration of endotoxin irrespective of the prevailing arterial blood pressure. Thereafter, it was raised above the control level. Two hours after endotoxin increased protein concentrations in cerebrospinal fluid were seen, results compatible with blood‐brain barrier damage and penetration of other substances; e.g. monoamines released during endotoxinaemia could thus be expected to have a direct influence on both cerebral blood flow and metabolism.
The Effects of High Dose Methylprednisolone or Fluid Volume Expansion on Cerebral Haemo‐dynamics and Oxygen Uptake in Endotoxic Shock. An Experimental Study in Dogs
Authors: EkströmJodal B. , Larsson L. E.
Published: January 2009

E. coli endotoxin has been shown to decrease cerebral blood flow (CBF) and increase cerebral metabolic late of oxygen (CMRO2) in normocapnic dogs. The aim of this study was to investigate the effects of different clinical treatments on the cerebral and central circulation already under the influence of endotoxin. Thus the animals were treated with either methylprednisolone or a lactated Ringer's solution. CBF, CMRO2 and intracranial pressure were followed. Central haemodynamic parameters, i.e. cardiac output, aortic pressure and pulmonary artery pressure, were also measured. Five dogs were given methylprednisolone (Solu‐Medrol®) 30 mg/kg 90 min after the endotoxin injection. Following this drug there were no significant changes in CBF when compared to controls. The primarily increased CMRO2 did, however, show a transient decrease. Five animals were treated with a lactated Ringer's solution (Ringerdex®), 30 ml/kg, given intravenously over 20 min starting 90 min after the endotoxin injection. In these animals, the cardiac output as well as CMRO2 returned to the values before endotoxin. CBF did not increase significantly.
The Use of Epidural Analgesia for Delivery in a Patient with Pulmonary Hypertension
Authors: Sørensen M. Bredgaard , Korshin J. D. , Fernandes A. , Secher O.
Published: January 2009

In a patient with severe pulmonary hypertension, haemodynamic observations, including cardiac output and pressure measurements in the systemic and the pulmonary circulation, were performed during vaginal delivery under selective segmental epidural block from T9 to L1 combined with Idatera1 pudendal blocks. No hypotensive episodes were observed in connection with the epidural block, but a gradual increase in the pulmonary pressures was observed during the stages of delivery. After perineal analgesia was achieved with bilateral pudendal blocks, a 2100 g girl with an Apgar score of 9 at 1 rnin was delivered by vacuuni extraction. The patient died 9 days after the delivery because of intractable cardiac failure.
The Haemodynamic Effects of Flunitrazepam in Anaesthetized Patients with Valvular or Coronary Artery Lesions
Authors: Hennart D. , D'Hollander A. , Primo‐Dubois J.
Published: January 2009

The haemodynamic efferts of flunitrazepam (FLU) 1.25 mg × m‐2 administered intravenously were studied in 18 anaesthetized cardiac patients suffering from isolated mitral (MIT, n = 6), aortic (AOR, n = 6) orcoronary (COR, n = 6) lesions. A placebo group of 18 clinically similar patients was used to asses the stability of the cardiovascular parameters under the conditions of the study. Heart rate. systemic arterial pressure, cardiac output and central venous pressure changes were measured 2, 5, 8 and 12 min after FLU or saline injection and compared with reference values collected before the start of the haemodynamic test. In the FLU group, the cardiovascular state of all the patients developed following the same pattern and the greatest differences were observed at 12 min post‐injection. These differences, expressed as a percentage 01 the initial values were (* P<0.05;** P <0.01;*** P< 0.001; ns = non‐significant): mean systemic arterial pressure: COR, ‐18% (**); MTT, ‐13% (*); AOR, ‐23% (**); heart rale: COR, 0% (ns); MIT, ‐10% (*); AOR, ‐12% (*); cardiac output: COR, ‐15% (**); MIT, ‐13% (*): AOR, ‐16% (**);. stroke volume: COR, ‐12% (*); MIT, 0% (ns); AOR, ‐3% (ns). This shows some differences concerning the SV and heart rate changes in the valvular and COR patients. As compared to the data from the literature, most of the haemodynamic effects of FLU seem relatively independent of the initial level of consciousness.
Autoregulation of Myocardial Blood Flow under Controlled Hypotension in the Dog
Authors: Jupa M. , Ducardus R.
Published: January 2009

The autoregulation of myocardial blood flow was studied under: (a) haemorrhagic hypotension (mean pressure decrease 40% from baseline); (b) drug‐induced hypotension with sodium nitroprusside or trimetaphan (40% pressure decrease); (c) drug‐induced hypotension (40% pressure decrease) after moderate blood loss of 20%. Dogs were used in experiments under general anaesthesia with sodium thiopentone and artificially ventilated with N2O/O2 (70%, 30%) and pancuronium. Under haemorrhagic hypotension, the flow was pressure‐dependent from the beginning. During nitroprusside hypotension, there was autoregulation of coronary flow to the level of mean pressure decrease 30% from control. Under trimetaphan, a constant flow persisted to the level of mean pressure decrease 20% from the baseline. Identical changes were seen during drug‐induced hypotension after moderate blood loss (20%). Central venous pressure, cardiac output, left ventricular stroke work and minute work changes are demonstrated. Blood gas data pH, Po2, Pco2 in the aortic and coronary sinus under drug‐induced hypotension are compared with control groups. There is a level of autoregulation of myocardial blood flow under hypotension. This level can be unfavourably changed in cases with hypertension and coronary obstructive diseases.
Monitoring of Optimal Oxygen Transport by the Transcutaneous Oxygen Tension Method in the Pig
Authors: Haldén E.
Published: January 2009

The validity of the transcutaneous oxygen tension (Ptco2) method as opposed to measurement of arterial oxygen tension (Pao2) and mixed venous oxygen saturation (SV̄O2), for monitoring optimal oxygen transport, was studied in six mechanically ventilated pigs with an oleic acid lung injury. With stepwise increments in positive end‐expiratory pressure (PEEP) from zero to 20 cmH2O, maximum oxygen flux was found at a PEEP of 8 cmH2O and named “optimal PEEP”. With increasing PEEP, cardiac output (CO) was maintained up to a PEEP of 8 cmH2O, when it began to decline, while venous admixture decreased at all respiratory settings up to a PEEP of 16, when it was about one‐fourth of the value (38.7%) at a PEEP of zero. Pao2 increased with rising PEEP and reached a steady level at a PEEP of 16 cmH2O. Ptco2 and Sv̄O2 parallelled each other and rose steeply up to a PEEP of 8 cmH2O. They showed a further slight increase up to a PEEP of 12 and alter that a tendency to decrease. It is concluded that Ptco2 and Sv̄o2 both seem to distinguish the optimal PEEP and give more adequate information than does Pao2. The Ptco2 method has the advantage of being non‐invasive.
Attenuation of the Circulatory Response to Laryngoscopy and Intubation by Fentanyl
Authors: Kautto U.‐M.
Published: January 2009

The effects of fentanyl on arterial pressure and heart rate increases during laryngoscopy and intubation were studied in 45 normotensive, surgical patients, who were randomly allocated to three groups receiving 2 or 6 μg/kg of fentanyl or saline in a double‐blind fashion before anaesthetic induction with thiopental. Fentanyl supplementation with 2 μg/kg significantly attenuated the arterial pressure and heart rate increases during laryngoscopy and intubation, and fentanyl, 6 μg/kg, completely abolished these responses. Moreover, fentanyl given during the induction decreased the amount of fentanyl needed during the operation. Respiratory depression was not observed during recovery.
Hemodynamic Effects of Massive Doses of Dexamethasone in Controlled Hypovolemic Shock in the Dog
Authors: Hellman A. , Häggendal E. , Lundberg D.
Published: January 2009

The hemodynamic effects of massive doses of dexamethasone in combination with the alpha‐adrenergic blocking agent phenoxybenzamine were studied in dogs subjected to hemorrhagic hypotension. Previously it has been shown that the glucocorticoid methylprednisolone, but not the glucocorticoid betamethasone, induces a pronounced vasodilation in combination with phenoxybenzamine. In the present study it was found that also dexamethasone (a stereoisomer of betamethasone) is unable to increase the peripheral blood flow after phenoxybenzamine. Since equivalent doses were used in relation to glucocorticoid activity, it seems reasonable to conclude that the different hemodynamic patterns are unrelated to the glucocorticoid ability of the drugs. Furthermore, it is unlikely that possible beneficial effects of dexamethasone in hypovolemir shock air due to a direct vascular iduence.
The Role of Halothane and Fentanyl in the Production of Balanced Anaesthesia
Authors: Tammisto T. , Aromaa U.
Published: January 2009

The aim of the study was to quantitate the degree of respiratory depression when tolerance of superficial nociception and of an endotracheal tube was achieved by supplementing N2O + O2 anaesthesia either with halothane alone or with halothane in combination with fentanyl. Eighty‐four patients, matched into sewn groups, were studied after induction of anaesthesia with thiopental (4 mg/kg) and suxamethonium (3 mg/kg) using the following supplementation: 0.8, 0.6, 0.4% halothane alone or 0.4, 0.2, 0% halothane with 0.5‐2 μg/kg fentanyl. After 10 min administration of the anaesthetic mixture using manual intermittent positive pressure ventilation (IPPV) (end‐tidal CO2 c. 5.5%), IPPV was discontinued and spontaneous respiration allowed to return. When the end‐tidal Co2 had stabilized, samples for blood gas analysis were taken and superfirial antinociception was tested by pinching an inguinal skin fold. Supplementation of an N2O + O2 mixture with 0.8% halothane without fentanyl or with 0.4% halothane with 0.5 μg/kg fentanyl seemed to come closest to the optimum in producing tolerance of an endotracheal tube and of superficial nociception (in about 85% of cases) with an increase in PCO2 to only 7 kPa.
Effects of Low‐Dose Ketamine and Thiopentone on Cardiac Performance and Myocardial Oxygen Balance in High‐Risk Patients
Authors: Pedersen T. , Engbæk J. , Klausen O. , Sørensen B. , WibergJørgensen F.
Published: January 2009

Induction of anaesthesia may pose a significant hazard to patients with critical cardiovascular status. Ketamine has been advocated as the drug of choice for maintaining cardiovascular performance during induction of anaesthesia in severely ill surgical patients. The purpose of this study was tocompare the relative changes in (he haemodynamic effects of ketamine and thiopentone during the first 30 min of anaesthesia induction measu red by thoracic impedance cardiography. Twelve adult high‐risk surgical patients, ASA class III‐V, were induced with thiopentone and fentanyl or with infusion of ketamine. Cardiac output decreased to 69% in the thiopentone group (P<0.05), but was hardly affected in the ketamine group. The pre‐ejection period to left ventricular time (PEPI) and thr pre‐ejection period index ratio increased significantly after thiopentone (P<0.05), while ketamine caused only minimal changes in left ventricular performance. The diastolic pressure time index to systolic pressure time index ratio decreased significantly in both groups.
Respirators and Respiratory Care
Authors: Bendixen H. H.
Published: January 2009

The intellectual and technological roots of respirators and respiratory care may be traced back hundreds of years. The clinical evolution has taken the better part of a century. and it has been most closely linked to the development of open‐chest surgery. Resuscitation and the treatment of poliomyelitis also have contributed ideas and technology to this evolution. If its successful performance had depended only on respirators. open‐chest surgery would have become clinical routine 50–80 years ago. In fact, many factors had to be under control, many modes of treatment had to be available, before the breakthrough in open‐chest surgery could occur. The most important factor may have been the effective control of sepsis and hemorrhage. Open‐chest surgery forced the change from single‐agent deep anesthesia with spontaneous ventilation to a balanced technique, using multiple drugs or agents, with controlled ventilation. Open‐chest surgery also necessitated that physicians specialize in anesthesiology. Scandinavian scientists and physicians have contributed greatly to the field of respirators and respiratory care, as has the specialty of anesthesiology.
Clinical Predictors of Intraoperative Myocardial Ischemia in Patients with Coronary Artery Disease Undergoing Non‐Cardiac Surgery
Authors: Coriat P. , Harari A. , Daloz M. , Viars P.
Published: January 2009

In order to detect the incidence of myocardial ischemia during the perioperative period and to determine during which situation it ocurred, continuous monitoring of the electrocardiogram by the Holter method was used in 51 patients with coronary artery disease who were undergoing a vascular surgical procedure. Clinical parameters measured preoperatively were evaluated as predictors of the occurrence of myocardial ischemia during the perioperative period. Twenty of 51 patients demonstrated 36 episodes of myocardial ischemia, which started in 11 cases during induction. Fourteen of 16 patients with disabling angina pectoris (Class III and IV) developed myocardial ischemia, whereas only six patients out of 35 with Class II or less or no angina experienced preoperative ischemic episodes (P < 0.001). All the patients without or with only mild angina who experienced perioperative ischemia showed ST‐T abnormalities at the preoperative resting electrocardiogram. Our data suggest that the risk of intraoperative myocardial ischemia can be predicted during the preoperative period by the degree of disability exhibited by patients with coronary artery disease.
Monocyte Functions are Depressed during and after Surgery under General Anaesthesia but not under Epidural Anaesthesia
Authors: Hole A. , Unsgaard G. , Breivik H.
Published: January 2009

Monocyte functions have been investigated in 18 patients undergoing total hip arthroplasty performed under either general anaesthesia or epidural anaesthesia. Serum cortisol increased significantly both per‐ and postoperatively in the general anaesthesia group compared to minor changes in the epidural group. The spreading of monocytes on plastic surfaces possibly reflects the phagocytic capacity of the cells. This spreading index of monocytes derived from patients operated under epidural anaesthesia and cultured in medium containing autologous serum showed a significant increase per‐ and postoperatively compared to the spreading index of monocytes from patients operated under general anaesthesia. This difference increased with increasing culture time. The ability of monocytes to induce lysis in malignant cells was reduced to 45% peroperatively in monocytes derived from patients operated under general anaesthesia and cultured in medium containing autologous serum. In the epidural group the lysis was nearly unchanged from the preoperative value, making the difference between the groups highly significant (P < 0.01). On the first postoperative day, the difference between the groups was less pronounced. The differences in spreading index and cytolytic capacity were not seen when the monocytes were cultured in medium with pooled AB‐serum, thus indicating a serum factor responsible for the monocyte depression when the patients were operated under general anaesthesia.
Effect of Supramaximal Vagal Stimulation in Combination with Hypoxia, Respiratory Acidosis and Deep Halothane Anaesthesia on Cardiovascular Function in Dogs
Authors: Korttila K. , Bastron R. D.
Published: January 2009

Vagal reflexes are generally recognized as a possible cause of cardiac arrest during anaesthesia. Studies were performed to determine whether hypoxia, respiratory acidosis or deep halothane anaesthesia modify the cardiovascular effect of vagal stimulation (VS) in dogs. The animals were anaesthetized with intravenous urethane and chloralose, and paralysed with metocurine. Normal temperature and arterial blood gas variables were maintained and supramaximal VS was applied to the distal end of both vagus nerves for 5 min. No differences were found in any of the variables measured among the time periods when VS was repeated five times in six control dogs receiving urethane‐chloralose basal narcosis only to determine the effects of time. VS resulted in 15 ± 3 s (mean ± s.e. mean) of asystole. Heart rate, cardiac output (CO) and mean arterial pressure (MAP) were still significantly decreased (p < 0.001) and central venous pressure, right atrial pressure. pulmonary capillary wedge pressure (PCW), systemic (SVR) and pulmonary vascular resistance significantly increased (p < 0.01 ‐ P < 0.001) at the end of stimulation when compared to values before VS in all 24 dogs. Neither hypoxia [Pao2 5.3 kPa (40 mmHg)] nor respiratory acidosis [pH 7.00, Paco2 10.6 kPa (80 mm Hg)] modified these effects of VS. VS during halothane anaesthesia (1.6% end‐tidal concentration) resulted in further significant decreases (P < 0.05 ‐ P < 0.001) in CO, MAP, mean pulmonary arterial pressure. PCW and SVR when compared to VS under basal narcosis. VS under halothane anaesthesia combined with hypoxia or respiratory acidosis did not decrease the cardiovascular parameters as much as VS under halothane Anaesthesia alone. VS alone, or in combination with hypoxia or respiratory acidosis, failed to cause persistent asystole.
Nitroprusside‐Hypotension: Cerebral Blood Flow and Cerebral Oxygen Consumption in Neurosurgical Patients
Authors: Larsen R. , Teichmann J. , Hilfiker O. , Busse C. , Sonntag H.
Published: January 2009

The effects of nitroprusside‐induced hypotension on cerebral blood flow and cerebral oxygen consumption were investigated in nine patients scheduled for cerebral arterial aneurysm surgery. Anesthesia was maintained with nitrous oxide/oxygen and fentanyl; muscle relaxation was achieved with pancuronium; Paco2 was maintained at 4.79‐5.32 kPa. Mean arterial pressure was reduced to 50 mm Hg by nitroprusside infusion after opening of the dura. Measurements were recorded and blood samples were taken 15 min before induction of hypotension, during stable hypotension and 15 min after termination of nitroprusside infusion. Measurements included: cerebral blood flow, using the argon‐washin technique, cardiac output (thermodilution), mean arterial pressure and heart rate. Cerebral blood flow averaged 56 ± 6 ml/min. 100 g before hypotension. Nitroprusside produced hypotension but did not significantly alter cerebral blood flow (61 ± 7 ml/min · 100 g). Cerebral blood flow remained virtually at preinfusion values upon cessation of infusion (53 ± 6 ml/min · 100 g). Cerebral oxygen uptake averaged 3 ± 0.2 ml/min · 100 g before hypotension and did not change significantly during hypotension (3.3 ± 0.3 ml/min · 100 g) and after termination of hypotension (2.7 ± 0.3 ml/min · 100 g). In two patients nitroprusside produced a 17 and 20% increase, respectively, in cerebral blood flow with no change in cerebral oxygen consumption, together with a marked increase in cardiac output and heart rate.
Reversal of Procaine Conduction Blockade by Adenine Nucleotides in Vivo and in vitro
Authors: Kraynack B. J. , Gintautas J.
Published: January 2009

The effect of the adenine nucleotides on procaine‐induced conduction block in rats was investigated in vivo and in vitro. Both adenine and cyclic nucleotides significantly shortened the duration of sciatic nerve Mucks in rats without affecting the frequency, degree of block or time of onset. Adenosine 5′ triphosphate (ATP) and N‐6, O2 dibutyryl 3′:5′‐monophosphate (db‐cyclic AMP) were most effective. In isolated sciatic nerve preparations. the adenine nucleotides (ATP, adenosine 5′diphosphate (ADP), adenosine 5′monophosphate (AMP)) rapidly reversed procaine‐induced depression of the action potential. These results suggest that local anesthetic effects may be mediated through interference with the physiological functions of the nucleotides.
A Study of EGG Abnormalities and Myocardial Specific Enzymes in Patients with Subarachnoid Haemorrhage
Authors: Rudehill A. , Gordon E. , Sundqvist K. , Sylvén C. , Wahlgren N. G.
Published: January 2009

Twenty‐two patients with subarachnoid haemorrhage were investigated for changes in myoglobin, total CK, CK‐MB and CK‐BB in serum and for the incidence of ECG abnormalities. Serial ECG's showed abnormalities in 20 patients; 15 of these had T wave changes, 15 Q‐Tc prolongation, ten had S‐T depression and n ine U waves and in seven cases arrhythmias were found. The purpose of the study was to find out whether a relationship could be established between these ECG abnormalities and changes in serum myoglobin and enzymes. However, in no patient could myoglobin or enzyme patterns consistent with acute myocardial or cerebral damage be observed and therefore the ECG abnormalities do not seem to be related to detectable myocardial damage.
Moderate Hypotensive Anaesthesia for Reduction of Blood Loss During Total Hip Replacement
Authors: Qvist T. F. , Skovsted P. , Sørensen M. Bredgaard
Published: January 2009

Thirty‐two consecutive patients scheduled for total hip replacement were randomly allocated to receive either neurolept anaesthesia or halothane anaesthesia. In the halothane group, systolic blood pressure was reduced to 10.69‐13.33 kPa in normotensive patients, and to 13.33‐16.0 kPa in hypertensive patients by adjusting the inspired halothane concentration and using supplementary fentanyl when necessary. In the neurolept group, no attempt was made to reduce blood pressure below the level achieved with adequate anaesthetic doses of fentanyl and droperidol. The average peroperative blood loss in the halothane group was 809 ml (range 250–1700 ml); this was significantly lower than in the neurolept anaesthesia group in which an average blood loss of 1909 ml (range 600–4900 ml) occurred. Moderate hypotensive halothane anaesthesia is recommended as an anaesthetic technique for total hip replacement.
Formation of Granulocytes and Macrophages in Mouse Bone Marrow Cultures Exposed to Various Anaesthetics
Authors: Benestad H. B. , Bjertnæs L. J. , Hersleth I. B.
Published: January 2009

The effects of anaesthetics on mouse bone marrow colony growth in vitro were examined. The culture dishes were kept in boxes of stainless steel, so that the composition of the pas phase could easily be controlled. After 1 week of culturing, cell colonies were counted. The cells (macrophages and in one type of culture also granulocytes) were then washed out of the dishes and counted. Enflurane, as well as halothane, present in the gas phase at concentrations used clinically, decreased the number of colonies and cells in a dose‐dependent fashion. However, intravenously administered drugs such as diazepam, fentanyl, alfentanyl, sufentanyl, thiopental and pentobarbital were not inhibitory at concentrations used in anaesthetic practice, but at least some of them depressed cell formation when high concentrations were used.
Hemodynamic and Metabolic Effects of Ketamine Anesthesia in the Geriatric Patient
Authors: Stefánsson T. , Wickstrom I. , Haijamäe H.
Published: January 2009

The cardiovascular and metabolic effects of ketamine as the sole anesthetic agent for surgical correction of fractured neck of femur were studied in eight spontaneously breathing geriatric patients (mean age 83 years) before premedication, at the end of operation, and 15 min and 2 h after the end of anesthesia. Arterial blood pressure, cardiac index, left ventricular stroke work index and oxygen consumption increased during anesthesia but had returned to preoperative levels 15 min after the end of anesthesia. Vascular resistance, heart rate and stroke volume index were not significantly changed. During anesthesia, arterial carbon dioxide tension increased whereas arterial pH and arterial BE decreased. The levels of glucose and lactate increased in both blood and skeletal muscle during anesthesia and remained elevated throughout the period studied but the lactate: pyruvate ratio was unchanged. High energy phosphagen levels in skeletal muscle did not change. Ketamine anesthesia in the spontaneously breathing geriatric patient induces cardiovascular stimulation and metabolic changes indicative of an increased sympathetic stimulation, whereas respiration is slightly depressed. The magnitude of these changes is, however, small and it thus seems that ketamine can be safely used as the sole anesthetic agent for hip fracture surgery in the average geriatric patient.
Effect of Neurolept and Epidural Analgesia on Cardiovascular Function and Tissue Metabolism in the Geriatric Patient
Authors: Stefánsson T. , Wickström I. , Haljamäe H.
Published: January 2009

The cardiovascular and metabolic effects of neurolept (NLA) and epidural analgesia were studied in geriatric patients (n=16, mean age 83 and 84 years, respectively) with hip fractures. Measurements were performed before premedication, at the end of operation as well as 15 min and 2 h after the end of anesthesia. During anesthesia and surgery no significant changes were seen in the studied hemodynamic variables (systemic and pulmonary arterial, central venous and pulmonary capillary wedge pressures, heart rate, cardiac index, stroke volume index, pulmonary and systemic vascular resistances) in either group. Fifteen minutes after the end of anesthesia cardiac index and heart rate rose in the NLA group while no changes were seen in the epidural group. During anesthesia and surgery, arterial oxygen tension (PaO2) increased in both groups due to increased inspired oxygen fraction. In the NLA group, arterial carbon dioxide tension (PacO2) was decreased due to the mechanical ventilation, and a slight decrease in arterial base excess (BEa) was also seen. A similar decrease in Bea occurred in the epidural group. In the postoperative period, PaCO2 increased and pH and BEa decrease significantly in the NLA group, while the only change seen in the epidural group was a slightly low BEa level. Blood glucose. lactate and pyruvate levels increased to a similar extent in both groups during anesthesia and surgery. However, in the postoperative period these levels continued to increase in the NLA group while partial normalization was seen in the epidural group. The lactate levels in skeletal muscle were increased in both groups during the postoperative period. Glucose‐6‐phosphate levels were increased during surgery and in the postoperative period only in the NLA group. No changes were seen in high energy phosphagen levels of skeletal muscle in either group during the studied time period. With the techniques used in the present study epidural analgesia as there are less hemodynamic, respiratory and metabolic effect in postoperative period.