bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Cardiopulmonary Bypass and Prostacyclin on Plasma Catecholamines, Angiotensin II and Arginine‐Vasopressin
Authors: FEDDERSEN K. , AURELL M. , DELIN K. , HÄAUGGENDAL J. , ARÉEAN C. , RÅARDEGRAN K.
Published: January 2009

Infusion of prostacyclin during cardiopulmonary bypass (CPB) reduces platelet activation, diminishes postoperative blood loss and decreases arterial blood pressure. In spite of continuous prostacyclin infusion, there is a delayed gradual rise in arterial pressure and resistance from low initial levels. We measured epinephrine (E), norepinephrine (NE), serotonin (5‐HT), angiotensin II (ATII) and arginine‐vasopressin (AVP) in plasma and carried out hemodynamic studies in 19 patients operated for coronary vascular disease. Eight patients served as a control group and were subjected to routine CPB. Eleven patients received prostacyclin 50 ng/kg/min during CPB. E and NE increased four‐ to sixfold during CPB from about 0.5 ng/ml (P <0.001). There was no difference between the groups. During CPB AVP increased sixfold from about 20 pg/ml in both groups (P <0.001), decreased early after CPB and increased again to high levels 3 h after CPB. The combined action of E, NE and AVP is of likely importance for the rise in systemic vascular resistance and/ or need of vasodilation during CPB in the control group. ATII did not increase in the control group, but increased fourfold to about 20 pg/ml (P <0.01) during CPB in the prostacyclin group. The addition of AT II to E, NE and AVP seems responsible for the gradual return of arterial pressure and resistance during prostacyclin infusion. Postoperative hypertension and/or need of vasodilation 3 h after CPB was associated with high AVP levels in both groups. Hypotension caused by prostacyclin infusion did not increase E, NE or AVP above levels produced by CPB and moderate hypotension alone.
Left Ventricular Function during Anaesthesia Induction and Sternotomy in Patients with Ischaemic Heart Disease A Comparison of Six Anaesthetic Techniques
Authors: MILOCCO I. , LÖOUF B. AXISON , WILLIAM‐OLSSON G. , APPELGREN L. K.
Published: January 2009

A comparison between five anaesthetic procedures, fentanyl (FE), morphine (MO), halothane (HAL), fentanyl/droperidol (NLA) and thiopenthone (two dose levels: PE 3 and PE 6), all supplemented with nitrous oxide, was performed with respect to the left ventricular function (LVF) during anaesthesia induction and sternotomy in 47 patients with good preoperative LVF and maintained β‐blockers. Peroperative LVF was characterized by left ventricular stroke volume (stroke index) and external pressure volume stroke work (left ventricular stroke work index) in relation to filling pressure (pulmonary capillary wedge pressure) and outflow resistance (systemic vascular resistance). The individual patient patterns in each group indicated normal LVF in the awake state. Anaesthesia induction was followed by a moderate depression of LVF in the HAL, MO, PE 3 and PE 6 groups at full dose of anaesthetic agent. After addition of nitrous oxide, there was also a decrease of preload in all groups, masking any additional depressions of LVF. The response to external stimuli, endotracheal intubation and sternotomy was that of mildly depressed LVF in the majority of the patients. The haemodynamic reactions in the FE and NLA groups were more varied. In all groups some patients (approximately 30%) showed signs of left ventricular failing in response to external stimuli. With the exception of the more variable haemodynamic reactions in the FE and NLA groups, the differences between the anaesthesia groups with respect to LVF depended mainly on extracardiac factors.
The Effect of High‐Dose Fentanyl Anaesthesia on P50in Man
Authors: Damen J. , Sprokholt R. , Sinclair D. , Maas A.
Published: January 2009

The effect of high dosage fentanyl anaesthesia on P50was studied in patients undergoing coronary bypass surgery. After induction of fentanyl anaesthesia 100 μg.kg‐1with pancuronium muscle relaxation P50changed significantly (P<0.005) from 3.40 ± 0.12 ± 3.33 ± 0.13 kPa. This anaesthesia technique decreases P50in vivo, but this has more theoretical than practical importance.
Surgical Stimulation during High‐Dose Fentanyl Anaesthesia: Effects of Dehydrobenzperidol on the Haemodynamics and Myocardial Oxygenation
Authors: Heikkilä H. , Jalonen J. , Arola M. , Laaksonen V.
Published: January 2009

Twenty‐four patients undergoing a coronary artery bypass grafting operation with high‐dose fentanyl (100 μg/kg)‐lorazepam‐oxygen anaesthesia were divided into a control group and a group receiving in addition 0.25 mg/kg dehydrobenzperidol (DHBP) before the skin incision (DHBP‐group). The changes in the central and coronary haemodynamics and the myocardial oxygenation were studied and compared between the two groups during the skin incision and sternotomy, in order to evaluate the possible effects of the dehydrobenzperidol in preventing the harmful haemodynamic effects of surgical stimulation during high‐dose fentanyl anaesthesia. In the control group a marked increase in the systemic vascular resistance and mean arterial pressure was seen during surgery. This haemodynamic stimulation was prevented by dehydrobenzperidol during the skin incision and markedly reduced during the sternotomy. Regardless of whether or not DHBP was given, a significant increase in the myocardial oxygen consumption was observed during the sternotomy; in the control group, the increase was slightly higher and was compensated by a greater increase in the myocardial oxygen extraction. No significant changes were seen in the coronary sinus blood flow or coronary vascular resistance in either group during the study period. The surgery caused no change in the myocardial lactate extraction in either group, although myocardial lactate production was observed in one control patient and the myocardial lactate extraction was markedly reduced in two other control patients and one DHBP patient.
Simulated Spontaneous Breathing. A New Model for Testing Anaesthetic Circuits
Authors: Zetterström H. , Jonsson L. O. , Kronander H.
Published: January 2009

A carbon‐dioxide‐producing lung model capable of simulating spontaneous breathing is presented. It consists of a piston in a cylinder, a mixing chamber and a dead space volume. The piston is driven by a direct‐current motor controlled by a micro‐processor and a servo unit. Respiratory waveform and rate, tidal volume, carbon dioxide production and dead space are easily adjustable within a wide range. The model is easy to handle and accurately mimics a given breathing pattern. It seems suitable for investigations of rebreathing and carbon dioxide elimination in different anaesthetic circuits.
The Venturi Anaesthesia Circuit I An All‐Purpose Breathing System for Anaesthesia
Authors: Jørgensen S. , Hansen L. K.
Published: January 2009

The Venturi is a flow‐accelerating injector, activated by fresh gas inflow from the anaesthetic machine. The Venturi entrains exhaled gas from the patient through a soda‐lime canister, and carries it to the patient together with fresh gas. The Venturi circuit is a Mapleson D system and the fresh gas requirements are roughly 30 ml kg‐1 min‐1 for anaesthetized, relaxed, adult patients under controlled ventilation.
Regional Anaesthesia in Paediatric Surgery
Authors: Serlo W. , Haapanemi L.
Published: January 2009

The use of regional anaesthesia in paediatric surgery remains controversial although the pharmacological and technical aspects, even in this age group, have been described. Many authors regard regional anaesthesia as contra‐indicated, and consequently general anaesthesia is preferred in paediatric surgery. In the present study regional anaesthesia was used in the form of supraclavicular, interscalene brachial plexus blockade, axillary brachial plexus blockade, lumbar epidural and spinal blockade in altogether 199 patients in the paediatric age group. Surgically excellent or satisfactory analgesia was achieved in 92–100% of the blocks. No complications were observed.
Vasodilator Responses to Enflurane in the Small Intestine
Authors: Henriksson B. Å. , Biber B. , Lundberg D. , Martner J. , Nilsson H. , Pontéan J.
Published: January 2009

Local effects of enflurane on intestinal vascular resistance were studied in vivo in cats. A jejunal segment was prepared and perfused at constant flow with blood from the femoral arteries. The intestine was either: (1) left with intact sympathetic innervation, (2) denervated and exposed to electrical post‐ganglionic vasoconstrictor nerve stimulation, or (3) excluded from neurogenic remote control by post‐ganglionic denervation. Enflurane dissolved in lipid and intra‐arterially administered to the jejunal segment in doses comparable to those clinically encountered, decreased intestinal vascular resistance in relation to the intra‐arterial concentration of the drug. The vasodilator response was, at the highest enflurane doses studied (blood concentration: 400 and 800 mg · l‐1), most pronounced in the intestine with intact sympathetic innervation. Otherwise, no differences were observed in vasodilator responses between the three different investigated modes of neurogenic influence on the intestine. In vitro enflurane (‐in‐lipid) did not affect the vasoconstrictor response to electrical field stimulation in the rat mesenteric arterioles. Enflurane, however, dose‐dependently reduced spontaneous contractile activity in the rat portal veins.
Intestinal Vascular Effects of Inhaled and Locally Administered Enflurane in the Cat
Authors: Henriksson B. Å. , Biber B. , Lundberg D. , Martner J. , Pontén J. , Sonander H.
Published: January 2009

The effects of enflurane on intestinal vascular resistance and blood flow in the intestine were studied in cats during basal chloralose anaesthesia. A jejunal segment was prepared and perfused with blood from both femoral arteries, allowing control of intestinal inflow pressure. Mesenteric venous blood flow was measured with an optical drop recorder. During constant intestinal arterial pressure (75 mmHg; 10 kPa), intestinal vascular resistance was calculated during enflurane inhalation at MAC 0.5 and 1.0 before and after post‐ganglionic denervation of the jejunal segment. Inhalation of enflurane reduced intestinal vascular resistance in a dose‐dependent fashion. The decrease in vascular resistance was attenuated but not abolished by post‐ganglionic denervation, indicating both peripheral and central nervous sites of action for enflurane. Furthermore, with the intestinal segment perfused at systemic arterial pressure, the effects of locally intra‐arterially infused enflurane dissolved in a fat emulsion was studied. A vasodilator response was elicited in the intestine when exposed to local arterial enflurane concentrations in the same range as encountered during surgical anaesthesia in man, supporting the hypothesis of a peripheral site of action.
Flow Pattern and Respiratory Characteristics during Halothane Anaesthesia
Authors: Jonsson L. O. , Zetterström H.
Published: January 2009

Using pneumotachography, the flow pattern was analysed in detail and tidal volume, respiratory rate, dead‐space to tidal volume ratio (VD/Vr) and carbon dioxide output were measured in adults (Group A, n= 12) and 3–8‐year‐old children (Group B, n= 10) during spontaneous breathing anaesthesia with halothane and surgery. The respiratory cycle was divided by equidistant points into 40 parts and the flow at each point related to peak inspiratory and expiratory flow. Thus a relative flow pattern was derived. This relative flow pattern was almost identical in both groups. Characteristically, the flow curve showed rapid turns from high expiratory to high inspiratory flow rates without any end‐expiratory flow pause (except in one adult). The minute ventilation was 6.6 ± 2.0 1 × min‐1 in Group A and 3.4 ± 0.6 1 × min‐1 in Group B, being correlated both to body weight and body surface area in Group A but not in Group B. The tidal volume was 210 ± 60 ml in Group A and 78 ± 13 ml in Group B, respiratory rate 31 ± 4 × min‐1 and 44 ± 10 × min‐1, respectively, and the VD/Vr ratio 0.40 ± 0.10 and 0.55 ± 0.12, respectively. Carbon dioxide output was 173 ml × min‐1 (STPD) in the adults and 82 ± 13 ml × min‐1 (STPD) in the children. It was correlated to both body weight and body surface area in the adults but not in the children.
Spinal Cord and Cerebral Blood Flow Responses to Subarachnoid Injection of Local Anesthetics with and without Epinephrine
Authors: Porter S. S. , Albin M. S. , Watson W. A. , Bunegin L. , Pantoja G.
Published: January 2009

Subarachnoid anesthesia with lidocaine, mepivacaine, or tetracaine with and without added epinephrine (1:100000) produced no demonstrable changes in average cerebral (CBF) or segmental spinal cord blood flow (SCBF) in 38 cats anesthetized with pentobarbital. Blood flow was measured by the injection of radioactive microspheres. Seven groups of cats received either lidocaine 15 mg, lidocaine 15 mg with epinephrine, mepivacaine 10 mg, mepivacaine 10 mg with epinephrine, tetracaine 5 mg, tetracaine 5 mg with epinephrine, or saline with epinephrine 1:100000. Mean arterial pressure (MAP) decreased significantly (P<0.05) in Groups I‐VI. Added epinephrine had no effect on the decrease in MAP. Amplitude of the somatosensory cortical evoked response decreased significantly in Groups I‐VI, but did not change from control in Group VII. No significant change in CBF or SCBF was demonstrated in any group at any time. Plasma lidocaine and mepivacaine levels were significantly less at 5 min after subarachnoid injection in the groups receiving epinephrine compared to those not receiving epinephrine (P<0.05). The data appear to support the hypothesis of a vasoconstrictive reduction in systemic absorption of intrathecal local anesthetics, but suggest that significant segmental spinal cord ischemia does not occur. Maintenance of total flow in the face of a decrease in MAP suggests that autoregulation in brain and spinal cord may be maintained. Changes in regional SCBF or CBF may have been present but were not examined in this study. Further studies of brain and spinal cord blood flow dynamics, regional flow changes, and regulation of flow after intrathecal agents are necessary.
Thiopental after Brain Ischemia in Monkeys. Cardiovascular and Electroencephalographic Effects
Authors: Gisvold S. E. , Safar P. , Alexander H. , Thompson M. E.
Published: January 2009

The cardiovascular and electroencephalographic (EEG) effects of thiopental were investigated, with and without preceding global brain ischemia (GBI). Four groups of pigtailed monkeys were used: Group I received thiopental 90 mg/kg over 1 h after 16 min GBI. Group II received thiopental 90 mg/kg over 1 h without preceding brain ischemia. Group III received 90 mg/kg over 1, 3, 6, or 8 h with varying infusion rates and no brain ischemia. Group IV, after 16 min GBI, received thiopental 90 mg/kg over 12 h with a gradually reduced infusion rate, keeping thiopental serum levels around 120–140 μmol‐1‐1 throughout the infusion. Large doses of thiopental (Group II) produced serious cardiovascular side‐effects. With co‐existing brain ischemia (Group I), these side‐effects were much worse; five of six animals not receiving lidocaine prophylaxis suffered circulatory arrest. A prolongation of the Q‐T interval on the electrocardiogram may be of pathogenetic importance. In contrast, lower thiopental blood levels, sufficient to depress the EEG to burst suppression or isoelectricity, were well tolerated with and without preceding brain ischemia (Groups IV and III).
Hypoxic Pulmonary Vasoconstriction in the Human Lung: the Effect of Prolonged Unilateral Hypoxic Challenge during Anaesthesia
Authors: Carlsson Å. Jolin , Bindslev L. , Santesson J. , Gottlieb I. , Hedenstierna G.
Published: January 2009

The influence of time on the pulmonary vasoconstrictor response to hypoxia was studied in six subjects during general anaesthesia and artificial ventilation prior to elective surgery. The lungs were intubated separately with a double‐lumen bronchial catheter. After preoxygenation of both lungs for 30 min, the test lung was rendered hypoxic for 60 min by ventilation with 5% O2 in N2, with the control lung still being ventilated with 100% O2. Cardiac output was determined by thermodilution, and the distribution of blood flow between the lungs was assessed from the excretion of a continuously infused poorly soluble gas (SF6). The fractional perfusion of the test lung decreased from 53% to 25% of cardiac output within the first 15 min of unilateral hypoxia. The pulmonary artery mean pressure increased by 14% and the pulmonary vascular resistance (PVR) of the test lung increased by 54%. Venous admixture increased from 21% to 39% of cardiac output, while the “true” shunt was maintained at about 15%. Arterial oxygen tension (Pao2) fell from 45 kPa to 12 kPa. Prolonging the unilateral hypoxic challenge caused no further change in the redistribution of the pulmonary blood flow, but cardiac output and pulmonary artery mean pressure continued to increase to 40%‐50% above control values after 1 h of hypoxia. The PVR of the test lung remained unchanged. The findings suggest that there is an immediate vasoconstrictor response to hypoxia in the human lung and that there is no further potentiation or diminution, of the response during a 60‐min period of hypoxia.
Hemodynamic Effects of Alfentanil in Verapamil‐Treated Dogs
Authors: Pedersen J. Lehd , Strøm J. , Berthelsen P. , Eriksen J. , Rasmussen J. P.
Published: January 2009

The hemodynamic effects of alfentanil were investigated in six dogs receiving verapamil 0.5 mg‐kg‐1and six dogs receiving saline in equal volume. Basic measurements were done after 30 min and the dogs were then given alfentanil 160 μg × kg‐1with measurements at 5, 15, and 30 min. Significant increases in central venous pressure (CVP), mean pulmonary arterial pressure and pulmonary wedge pressure (PWP) were found 30 min after verapamil. After verapamil‐alfentanil, increases were seen in CVP and PWP at 5 and 15 min and in PWP at 30 min. Mean arterial pressure and cardiac index were unchanged, while a decrease in heart rate was fully compensated by an increase in stroke volume. Indices of contractility were unchanged. All values were within the limits of normal hemodynamic function. We conclude that high‐dose alfentanil has no adverse effects on hemodynamic parameters during calcium blockade.
Effects of Adjuvants to Local Anaesthetics on Their Duration
Authors: HASSAN H. G. , ÅKERMAN B. , RENCK H. , LINDBERG B. , LINDQUIST B.
Published: January 2009

The effects of addition of hyaluronic acid (sodium hyaluronate, Healon®) to different local anaesthetics of the amide type on the duration of sensory or motor blocks following various regional anaesthetic procedures were studied in animal experiments. In the rat infra‐orbital nerve block model, the addition of 0.1‐0.5% hyaluronic acid (HA) to 2% prilocaine increased the duration of sensory block of varying degrees in a dosedependent way by up to 500% of values obtained with plain prilocaine. The duration of degree 5 blocks produced by 0.5% etidocaine and 0.5% bupivacaine was also significantly prolonged when 0.4% HA was included to 206% and 282% of control, respectively, while blocks induced by 2% lidocaine were prolonged to 123% of control. The duration of motor block following spinal anaesthesia in the mouse was prolonged in a dose‐dependent way when HA was added to prilocaine, bupivacaine and etidocaine. For solutions containing 0.4% HA, prolongations to 254%, 166% and 134% of control, respectively, were obtained. A concomitant increase of latency to onset of block and failure rate occurred with increasing concentrations of HA. The duration of corneal anaesthesia in the rabbit increased by 57% and 44% when 0.3% HA was added to prilocaine and bupivacaine, respectively. The duration of infiltration anaesthesia was not affected by the addition of HA to the local anaesthetic solutions. Addition of HA had no effect on the onset, depth and duration of prilocaine‐induced block of the nervous transmissionin vitro. The duration of infra‐orbital nerve block and spinal anaesthesia shows a significant relation to the relative viscosity of the local anaesthetic solution.
Midazolam versus Fentanyl/Droperidol and Placebo as Intramuscular Premedicant
Authors: VAN WIJHE M. , VOOGT‐FRENKEL E. DE , STIJNEN T.
Published: January 2009

Midazolam, a new short‐acting benzodiazepine with promising premedicant effects, was investigated in a double‐blind, randomized clinical trial in 203 patients versus fentanyl/droperidol and placebo. Subjective effects, side‐effects, amnesia and overall satisfaction were recorded. Midazolam caused the greatest decrease in anxiety level, and while causing more confusion and somnolence than placebo, caused less confusion and somnolence than fentanyl/droperidol. Half the patients who received midazolam reported anterograde amnesia. No serious side‐effects were reported. Patient satisfaction was greater in the midazolam group than in the other groups.
The Effect of Diazepam Pretreatment on the Succinylcholine‐Induced Rise in Intraocular Pressure
Authors: FJELDBORG P. , HECHT P. S. , BUSTED N. , NISSEN A. B.
Published: January 2009

The influence of diazepam on some adverse effects of succinylcholine was studied double‐blind. Thirty patients (ASA I‐II) were allocated to groups receiving either diazepam 0.08 mg/kg or d‐tubocurarine 0.05 mg/kg 5 min before a bolus of succinylcholine, 1 mg/kg and 1.5 mg/kg, respectively. Fasciculations were more frequent in the diazepam group (80%) than in the d‐tubocurarine group (13%). Relaxation, onset and duration of neuromuscular blockade were comparable in the two groups. The rise in intraocular pressure after succinylcholine and endotracheal intubation was small (0.27 kPa = 2 mmHg) but significant (P<0.01) after diazepam pretreatment. In this group the rise in intraocular pressure was 50% lower than the rise seen in the d‐tubocurarine group (P<0.01). We conclude that pretreatment with diazepam 0.08 mg/kg will reduce but not prevent a rise in the intraocular pressure after succinylcholine in a rapid sequence induction. In the management of patients with penetrating eye injuries the use of succinylcholine still carries some risk even after diazepam pretreatment.
Continuous Positive Airway Pressure Increases Vagal and Phrenic Nerve Activity in Cats
Authors: NORSTED T. , JONZON A. , SEDIN G.
Published: January 2009

To investigate how continuous positive airway pressure (CPAP) changes the vagal nerve activity and whether CPAP alters the efferent phrenic nerve activity or the breathing pattern similarly before and after vagotomy, a study was made of vagal and phrenic nerve activity in chloralose‐anaesthetized cats. In the vagal nerve, CPAP increased the mean impulse frequency during expiratory rest. The breath‐related impulse frequency also increased with CPAP. With higher CPAP (≥ 0.5 kPa), the peak of breath‐induced activity in the vagal nerve lasted longer than inspiration. In the phrenic nerve, the impulse frequency in the bursts increased almost linearly with CPAP irrespective of whether the vagal nerves were intact or not. The duration of the phrenic nerve bursts decreased with increasing CPAP when the vagal nerves were intact. When the vagal nerves were cut, the burst duration did not change. The rate of breathing was almost unchanged by CPAP regardless of whether the vagal nerves were cut or not. The inspiration/expiration ratio decreased with increasing CPAP when the vagal nerves were intact, but not when they were cut.
Respiratory Performance after Upper Abdominal Surgery. A Comparison of Pain Relief with Intercostal Blocks and Centrally Acting Analgesics
Authors: ENGBERG G.
Published: January 2009

The respiratory capacity was studied during the first 2 days postoperatively in 94 patients, aged 19 to 75 years and undergoing surgery through an upper abdominal incision. Postoperative pain relief was randomly administered, either by intercostal block (i. c. b.) and centrally acting analgesics on demand, or by centrally acting analgesics alone. Respiratory studies comprising forced vital capacity (FVC), forced expiratory volume in one second (FEV1), peak expiratory flow rate (PEF) and analysis of arterial blood gases were made. Bilateral i. c. b. given after surgery performed through a midline incision did not improve the respiratory function, whereas unilateral i. c. b. after surgery through a subcostal incision had positive effects. Thus postoperative i. c. b. following cholecystectomy performed through a subcostal incision resulted in higher FVC, FEV1 and PEF values than without i. c. b. at least during the time of effective nerve block. I. c. b. after subcostal incision also improved arterial oxygen tension. The patients undergoing cholecystectomy and receiving a second i. c. b. 8 h after the first one had better respiratory function than the patients without any block during the first 2 days postoperatively.
Factors Influencing the Respiratory Capacity after Upper Abdominal Surgery
Authors: ENGBERG G.
Published: January 2009

The analgesic requirement and some factors influencing the respiratory capacity after upper abdominal surgery were studied during the first 2 days postoperatively in 417 patients, aged 17 to 84 years, undergoing surgery in the upper part of the abdomen. The operations were cholecystectomy or choledocholithotomy through a subcostal incision, partial gastric resection, repair of a diaphragmatic hernia or vagotomy through a midline incision. Pain relief was achieved in a random order either by intercostal block (i. c. b.) and centrally acting analgesics on demand, or by centrally acting analgesics alone. The analgesic demand was recorded, and the respiratory capacity was monitored by the peak expiratory flow rate (PEF). A smaller analgesic requirement and a smaller change in PEF were found after cholecystectomy than after any other kind of surgery. The demand for analgesics was age‐dependent, and patients under 60 years of age demanded more than those aged 60 years and older. Bilateral i. c. b. given after surgery through a midline incision had few advantages, but unilateral i. c. b. following cholecystectomy and choledocholithotomy with a subcostal incision had positive effects. Thus it decreased the demand for centrally acting analgesics and resulted in higher PEF values than without i. c. b. for cholecystectomy during the period of effective nerve block and for choledocholithotomy for 2 whole days postoperatively. Smokers seemed to benefit from i. c. b. for 2 postoperative days. The reduction of PEF after cholecystectomy also seemed to be related to the duration of treatment with centrally acting analgesics.
Methylprednisolone Reduces Vascular Resistance in Hypoxic and Atelectatic Lungs
Authors: STRØMME‐HANSEN L. , BJERTNÆS L. J. , VAAGE J.
Published: January 2009

The effect of pharmacological doses of methylprednisolone (MP) on the pulmonary vasoconstrictor response to hypoxia has been investigated in two groups of isolated rat lung preparations, one consisting of ventilated, and the other of atelectatic lungs. In both groups, MP reduced the vasoconstrictor response to hypoxia in a dose‐dependent fashion. At a perfusate concentration of 3 mmol/1 of MP, the response was reduced by about 80%. On the contrary, the vasoconstrictor response to injections of standardized doses of angiotensin II, used as an independent vasoconstrictor substance, were not significantly changed by MP, even when administered at a concentration which completely abolished the response to hypoxia. We suggest that MP inhibits the pulmonary vasoconstrictor response to hypoxia without influencing the general reactivity of the pulmonary vascular bed.
Methemoglobinemia Associated with a Prilocaine‐Lidocaine Cream and Trimetoprim‐Sulphamethoxazole. A Case Report
Authors: JAKOBSON B. , NILSSON A.
Published: January 2009

A case of moderate methemoglobinemia in an infant treated with trimetoprim‐sulphamethoxazole and a topical mixture of lidocaine and prilocaine is described. The possibility of an additive interaction between sulphamethoxazole and prilocaine is discussed, as well as the mechanism and therapy of methemoglobinemia.
Haemodynamics and Myocardial Oxygenation during Anaesthesia for Coronary Artery Surgery: Comparison between Enflurane and High‐Dose Fentanyl Anaesthesia
Authors: HEIKKILÄ H. , JALONEN J. , AROLA M. , LAAKSONEN V.
Published: January 2009

Changes in central and coronary haemodynamics and myocardial oxygenation during anaesthesia induction, intubation, skin incision and sternotomy were studied in 24 patients undergoing a coronary artery bypass grafting operation under either high‐dose fentanyl or enflurane anaesthesia. The anaesthesia induction caused no changes in the coronary haemodynamics in either group, in spite of a marked decrease in the coronary perfusion pressure during enflurane induction. In both groups a decrease in the coronary sinus blood flow and an increase in the coronary vascular resistance was observed after the intubation. At this stage, two patients in both groups had a low level of myocardial lactate extraction, indicating possible myocardial ischaemia; mean myocardial lactate extraction had decreased significantly from the awake level in both groups. A circulatory response to surgical stimulation was seen in both groups, although it could be somewhat better controlled during enflurane anaesthesia. In the enflurane patients the increase in myocardial oxygen demand was accompanied by increased coronary flow, while in the fentanyl group the increase in coronary flow was not in proportion to the increased oxygen demand, and an increase in myocardial oxygen extraction was also seen. During surgery, three fentanyl patients and one enflurane patient had a low level of myocardial lactate extraction.
The Pharmacokinetics of Methohexital in Young and Elderly Subjects
Authors: GHONEIM M. M. , CHIANG C. K. , SCHOENWALD R. D. , LILBURN J. K. , DHANARAJ J.
Published: January 2009

The pharmacokinetics of methohexital were investigated in ten young adult volunteers and in seven young and seven elderly patients. The latter two groups underwent enflurane and nitrous oxide anesthesia and surgery. Each subject received a bolus dose of 2 mg/kg of methohexital intravenously. Plasma levels of the drug were measured for 8 h after injection by gas chromatography using a nitrogen detector. Anesthesia (combined with surgery) and increase in age did not separately affect the kinetics of the drug; however, the elimination half‐life was longer in the elderly patients group than in the young non‐anesthetized volunteers.
CBF and CMRO2 during Continuous Etomidate Infusion Supplemented with N2O and Fentanyl in Patients with Supratentorial Cerebral Tumour. A Dose‐Response Study
Authors: COLD G. E. , ESKESEN V. , ERIKSEN H. , AMTOFT O. , MADSEN J. B.
Published: January 2009

In 14 patients with supratentorial cerebral tumours with midline shift below 10 mm, CBF and CMRo2 were measured (Kety & Schmidt) during craniotomy. The anaesthesia was continuous etomidate infusion supplemented with nitrous oxide and fentanyl. The patients were divided into two groups. In Group 1 etomidate infusion of 30 μg kg‐1 min‐1 was used throughout the anaesthesia, and CBF and CMRo2 were measured twice. In this group CMRo2 (± s. d.) averaged 2.31±0.43 ml O2 100 g‐1 min‐1 70 min after induction and 2.21 ± 0.38 ml O2 100 g‐1min‐1 130 min after induction. In Group 2 the etomidate infusion was increased from 30 to 60 μg kg‐1 min‐1 after the first study and a significant fall in CMRo2 from 2.52 ± 0.56 to 1.76 ± 0.40 ml O2 100 g‐1 min‐1 was found. Simultaneously, a significant fall in CBF was observed. The CO2 reactivity was preserved during anaesthesia.
Circulatory Effects of Haemorrhage during Sodium Nitroprusside Induced Hypotension A Study in the Rat
Authors: GUSTAFSON C. , ARONSEN K. F. , ROSBERG B.
Published: January 2009

The haemodynamic changes induced by acute moderate blood loss were investigated in rats during normotensive halothane anaesthesia and during sodium‐nitroprusside‐induced hypotensive anaesthesia, respectively. Following haemorrhage in the normotensive group, mean arterial blood pressure, heart rate and left cardiac work decreased. Cardiac output was reduced non‐significantly. Blood flow was redistributed to favour cerebral, coronary, renal and hepatic circulation, mainly at the expense of blood flow to the carcass. Following haemorrhage in the hypotensive group, cardiac output increased significantly. Mean arterial pressure, heart rate and left cardiac work were unchanged. Absolute values for cerebral, coronary, renal and hepatic blood flow were maintained or even increased, while blood flow to the carcass was unchanged.
Multiple Intercostal Blocks by a Single Injection? A Clinical and Radiological Investigation
Authors: JOHANSSON A. , RENCK H. , ASPELIN P. , JACOBSEN H.
Published: January 2009

Three different techniques for producing multiple intercostal nerve blocks using bupivacaine were compared in volunteers. The techniques used were multiple injections at intercostal nerves 7–11, or a single injection employing a needle or a catheter inserted in the 9th intercostal space. The injections were made at the costal angle. The anatomical spread of a mixture of a local anaesthetic and a radio‐opaque fluid following the single injection technique at the ninth intercostal space or at the subcostal space was evaluated by computerized x‐ray tomography (CT). The distribution of cutaneous analgesia/hypalgesia following all techniques was evaluated by pin prick. No spread of the local anaesthetic to adjacent intercostal spaces or to the paravertebral space could be shown by CT. The distribution of cutaneous analgesia was limited to three segments or less following a single injection. No difference in blood levels of bupivacaine could be found. It is concluded that the single injection technique of producing multiple intercostal nerve blocks is inferior to the multiple injection technique.
Hemodynamics and Oxygen Transport after Partial and Total Blood Exchange with Pyridoxalated Polyhemoglobin in Dogs
Authors: HOBBHAHN J. , VOGEL H. , KOTHE N. , BRENDEL W. , PETER K. , JESCH F.
Published: January 2009

The effects of a pyridoxalated polyhemoglobin solution ((SFH‐PLP)n‐solution) on cardiovascular hemodynamics and oxygen transport were investigated in a model of partial and total blood exchange in seven dogs. Cardiac output, mean arterial pressure and heart rate were essentially unchanged, even after total blood exchange, due to the long plasma half‐disappearance time of (SFH‐PLP)n (36 h) and due to the addition of albumin to the solution. The oxygen‐binding capacity of (SFH‐PLP)n was 1.1 to 1.2 ml O2/g hb. Oxygen availability was reduced to about 50%, resulting from the low hemoglobin concentration and the decreased oxygen‐binding capacity of (SFH‐PLP)n. Since cardiac output did not increase, O2‐consumption was maintained by an increase in O2‐extraction from 21 to about 50%. However the decrease in mixed venous Po2 to values not below 30 mmHg (4.00 kPa) proves the sufficient unloading capacity of (SFH‐PLP)n. The adequate tissue oxygenation of (SFH‐PLP)n could be demonstrated by the lack of a metabolic acidosis, the essentially unchanged Po2‐histograms of the skeletal muscle and the only moderate decrease in mixed venous Po2. Four dogs survived for more than 3 days;
Edrophonium and Neostigmine for Reversal of the Neuromuscular Blocking Effect of Vecuronium
Authors: ENGBÆK J. , ØRDING H. , ØSTERGAARD D. , VIBY‐MOGENSEN J.
Published: January 2009

The effect of edrophonium for reversal of the non‐depolarizing neuromuscular blockade produced by a continuous infusion of vecuronium was compared to that of neostigmine in 20 adult patients during neurolept anaesthesia. When antagonism was attempted at 10% twitch height recovery, reversal time to a train‐of‐four ratio of 0.7 was significantly shorter following neostigmine 0.04 mg/kg than after edrophonium 0.75 mg/kg (9.8 min and 18.7 min, respectively) but the same after edrophonium 1.5 mg/kg (10.3 min). There was no statistically significant difference in reversal time between neostigmine 0.04 mg/kg given at 10% twitch height and edrophonium 0.75 mg/kg given at 25% twitch height recovery (6.0 min). Additional doses of atropine were necessary following edrophonium 1.5 mg/kg.
Epidural Fentanyl Counteracts Sympathetic Gastric Inhibition
Authors: Lisander B. , Stenqvist O.
Published: January 2009

Postoperative paralytic ileus is in part mediated by the sympathetic gastrointestino‐gastrointestinal (GI‐GI) reflex. The modulation of this reflex by epidural fentanyl (50 μg) was studied in chloralose‐anesthetized, ventilated cats. The vagi were cut in the neck but could be efferently stimulated. Gastric volume, arterial pressure and heart rate were followed and the GI‐GI reflex was elicited by intestinal distension, mesenteric afferent nerve stimulation or heating or capsaicin administered intra‐arterially to an intestinal loop. Epidural fentanyl enhanced the gastric contraction response to efferent vagal stimulation and considerably counteracted the GI‐GI reflex inhibition of vagally induced tone. These effects were reversed by epidural naloxone (10 μg). In contrast, 50 μg of fentanyl i. v. only enhanced the effect of vagal stimulation but had no influence on the inhibitory GI‐GI reflex responses. Apparently, epidural fentanyl may inhibit the GI‐GI reflex by a spinal point of action.
Postoperative Pain Treatment after Upper Abdominal Surgery with Epidural Morphine at Thoracic or Lumbar Level
Authors: Larsen V. Højkjær , Iversen A. D. , Christensen P. , Andersen P. K.
Published: January 2009

Thirty patients undergoing upper laparotomy were entered into a randomized trial, comparing the effect of midthoracic (T) and lumbar (L) epidural morphine on postoperative pain and pulmonary function. Five mg morphine was injected through the catheter at the end of the operation, and subsequently three times a day. Six, 30 and 54 h postoperatively, the following tests were performed: linear analogue pain score, arterial gas tensions (PaO2, PaCO2 and pH), forced ventilatory capacity (FVC), forced expiratory volume in 1 s (FEV1) and peak expiratory flow rate (PEF). The changes in pain score (increase of the median): T: 21, 6, 5, and L: 24, 15, 8 per cent of full scale), PaO2 (decrease of the tension: T: 1.7, 2.1, 2.4, and L: 2.0, 2.8, 2.0 kPa), PaCO2, pH, FVC (decrease of the volume: T: 1.3, 1.1, 0.9, and L: 1.3, 1.3, 1.2 1). FEV1 and PEF from the preoperative tests were not significantly different. It is concluded that the clinical effect of epidural morphine for postoperative pain treatment is the same or little different whether the administration takes place at the thoracic or lumbar level.
Post‐operative Analgesia by Epidural Versus Intramuscular Nicomorphine after Thoracotomy. Part I
Authors: Hasenbos M. , VAN Egmond J. , Gielen M. , Crul J. F.
Published: January 2009

One hundred and sixty‐three patients subjected to three different types of thoracic operation were allocated randomly either to balanced intravenous anaesthesia including i. v. opiates with post‐operative intramuscular opiates (intramuscular group) or to balanced intravenous anaesthesia without i. v. opiates but with high thoracic epidural regional block during the operation as well as epidural nicomorphine post‐operatively (epidural group). Post‐operative nicomorphine was given only at the request of the patient and as frequently as needed to obtain satisfactory pain relief. Patients in the epidural group received nicomorphine exclusively by epidural injection. In this paper (Part I), general parameters between the epidural group and the i. m. group are compared. The epidural group showed acceptable cardiovascular stability during the operation. With the catheter tip at the T3‐T4 level, there was apparently a preferential spread downwards of the local anaesthetics. Post‐operatively both groups (i. m. and epidural) provided effective and rapid onset of analgesia. There were no major differences in post‐operative pain assessment, either by the patient or by the team.
Post‐operative Analgesia by Epidural Versus Intramuscular Nicomorphine after Thoracotomy. Part II
Authors: Hasenbos M. , VAN Egmond J. , Gielen M. , Crul J. F.
Published: January 2009

One hundred and sixty‐three patients subjected to three different types of thoracic operation were allocated randomly either to balanced intravenous anaesthesia including i. v. opiates with post‐operative intramuscular opiates (intramuscular group) or to balanced intravenous anaesthesia without i. v. opiates but with high thoracic epidural regional block during the operation as well as epidural nicomorphine post‐operatively (epidural group). Post‐operative nicomorphine in either group was given only at the request of the patient and as frequently as needed to obtain satisfactory pain relief. Patients in the epidural group were given nicomorphine exclusively by epidural injection. Patients in the epidural group required significantly less nicomorphine for effective pain relief (29 mg (sd = 10) over a period of 3 days compared to 52 mg (sd = 27) in the intramuscular group. Significantly fewer pulmonary complications in the epidural group were observed (9 atelectases in 83 patients in the epidural group compared to 24 atelectases in 80 patients in the intramuscular group). Only one patient developed pneumonia (intramuscular group). Although the epidural catheter was inserted at the T3‐T4 level, no signs of ventilatory depression were found; on the contrary, respiration in the epidural group was significantly better than the intramuscular group. None of the patients, in either analgesia group, needed to be ventilated post‐operatively.
Reduction of the Slow Inward Current of Isolated Rat Ventricular Cells by Thiamylal and Halothane
Authors: Ikemoto Y. , Yatani A. , Arimura H. , Yoshitake J.
Published: January 2009

The barbiturates and halothane exert a negative inotropic effect on the myocardium. A reduction in the slow inward current, carried mainly by calcium ions, is an important factor for the underlying mechanism because the calcium current during the action potential provides the calcium ions for accompanying contraction, supplies Ca ions to the sarcoplasmic reticulum for subsequent contractions, and induces Ca release from the store site. It has been suggested that reduction in the slow inward current caused by anesthetics is indicated by depression of the slow action potential of the partially depolarized myocardium. In order to assess directly the effect of anesthetics on the slow inward current, we carried out voltage clamp experiments with single isolated rat ventricular cells obtained by an enzymatic dissociation method. Thiamylal (10‐4mol·1‐1) and halothane (1%) decreased the slow inward current to 60 ± 5% (mean ± s. d., n = 8) and to 65 ± 10% (mean ± s. d., n = 8) of the control value, respectively, without changing the configuration of the current‐voltage curve. The results provide further evidence for anesthetic reduction of the slow inward current of the myocardium, and suggest that the negative inotropic effect is at least partly due to the reduction in that current.
Infectious Complications of Percutaneously Inserted Central Venous Catheters
Authors: Lindblad B. , Wolff T.
Published: January 2009

The frequency of early and late complications of percutaneously inserted central venous catheters (CVC) was prospectively assessed. One hundred and fifty‐one periods of catherization (siliconized and heparinized polyethylene and teflon catheters), inserted mainly infraclavicularly and on the right side, were evaluated. Strict aseptic technique was used during insertion and daily care of the CVC. The only early complications noted were three cases of pneumothorax. No nerve injuries or arterial punctures were observed. Of 124 evaluated cases (96 arm‐phlebography, 28 post‐mortem) 16% developed thrombosis, and in one patient this probably resulted in fatal pulmonary embolism. Septicaemia was seldom seen: two cases were considered as proved and another two cases as probable. This study and other studies indicate that an aseptic technique is essential and perhaps even more important than using tunnelled versus percutaneously inserted catheters in respect of reducing infectious complications of central venous catheters.
Buprenorphine Delays Drug Absorption and Gastric Emptying in Man
Authors: Adelhøj B. , Petring O. U. , Ibsen M. , Brynnum J. , Poulsen H. E.
Published: January 2009

The aim of the present study was to investigate the effects of buprenorphine on drug absorption and gastric emptying in man, using paracetamol absorption as an index of gastric emptying rate. Paracetamol was given to eight healthy volunteers p. o. together with or without a single i. v. dose of buprenorphine 4 μg kg‐1body weight. Nausea occurred in five of the subjects, four subjects vomited and one was excluded due to vomiting during the study period. The mean peak serum paracetamol concentration (Cmax) was significantly (P< 0.0002) lowered by a factor 3 by buprenorphine, the mean time from administration of paracetamol to its peak concentration (Tmax) was significantly (P<0.03) prolonged by a factor 6, and the area under the plasma concentration‐time curve from 0 to 120 min was significantly (P<0.00006) reduced by a factor 3. This demonstrates a marked inhibition of the rate of paracetamol absorption, indicating a clinically important reduction of gastric emptying following administration of buprenorphine.
Effects of a Thermal Ceiling on Postoperative Hypothermia
Authors: Henneberg S. , Eklund A. , Joachimsson P. O. , Stjernström H. , Wiklund L.
Published: January 2009

Moderate per‐ and postoperative hypothermia initiates an increased metabolism in the postoperative period. The subsequent demands on oxygen transport may be critical in poor risk patients. Nineteen healthy young women with moderate hypothermia after abdominal surgery were studied for 2 h postoperatively with or without external heating from a heating ceiling. Central and peripheral temperatures, oxygen consumption, plasma catecholamines and shivering were measured. A method for continuous measurement of oxygen consumption and carbon dioxide production during spontaneous breathing is described. The results suggest that postoperative external heating decreases oxygen consumption, shivering and plasma catecholamine levels. At the same time, the comfort of the patient is increased considerably.
Comparison of Adrenaline and Phenylephrine in Out‐of‐Hospital Cardiopulmonary Resuscitation: A Double‐Blind Study
Authors: Silfvast T. , Saarnivaara L. , Kinnunen A. , Erosuo J. , Nick L. , Pesonen P. , Luomanmäki K.
Published: January 2009

Phenylephrine, a strong alpha‐adrenergic receptor‐stimulating agent, was compared with adrenaline in 65 patients with out‐of‐hospital cardiac arrest, in a double‐blind study. The resuscitation was performed by the physician‐staffed Prehospital Emergency Care Unit of Helsinki University Central Hospital. The patients received either 1.0 mg of phenylephrine or 0.5 mg of adrenaline i. v. in the treatment of fine ventricular fibrillation, asystole or electromechanical dissociation. If two doses of either drug did not restore circulation, 0.5 mg of known 0.01% adrenaline was given i. v., maximally twice. In the adrenaline group, which consisted of 36 patients with a mean age of 61 years, 10 patients (28%) were successfully resuscitated. The phenylephrine group consisted of 29 patients with a mean age of 62 years. In this group nine patients (31%) were successfully resuscitated. The two groups were comparable regarding their apnoea‐times, and there was no difference in the need for extra adrenaline between the groups. No adverse effects, such as hypertension or bradycardia, were noted in the patients treated with either adrenaline or phenylephrine, nor did the overall rate of successful resuscitation fall during the test period. It is concluded that phenylephrine seems as effective as adrenaline in the treatment of cardiac arrest, but further studies seem warranted.