bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of midazolam, droperidol, fentanyl, and alfentanil on phagocytosis and killing of bacteria by polymorphonuclear leukocytes in vitro
Authors: Krumholz W. , Endrass J. , Knecht J. , Hempelmann G. 
Published: January 2009

Polymorphonuclear leukocytes (PMNL) make an outstanding contribution to the defence against invading bacteria. We studied the effects of midazolam, droperidol, fentanyl, and alfentanil on phagocytosis and killing of Staphylococcus aureus and Escherichia coli by PMNL in vitro.Using a method described by Eggleton et al. (5), PMNL were isolated from venous blood samples obtained from ten volunteers. The fluorescence microscopic method mentioned by Bellinari‐Pires et al. (6) was used to examine phagocytosis and killing.Whereas both midazolam and droperidol caused a significant inhibition of phagocytosis as well as bactericidal activity, fentanyl and alfentanil did not influence these PMNL functions.In order to find out whether midazolam and droperidol are able to intensify perioperative bacterial infections in vivo as well, additional clinical studies should be conducted.
Diltiazem does not increase ventricular fibrillation threshold during hypothermia
Authors: Bjørnstad H. , Jenssen D. , Mortensen E. 
Published: January 2009

This study was designed to investigate whether the calcium channel blocker diltiazem affects the threshold for ventricular fibrillation during hypothermia in dogs.Ten dogs were cooled from 37 to 25°C and rewarmed to 37°C. The threshold for ventricular fibrillation was determined at body temperatures 37, 34, 31, 28 and 25°C by programmed electrical stimulation using a stimulation protocol which involved application of maximal five extrastimuli. At 25°C, six dogs were given an i.v. bolus dose of 100 μg‐kg‐1followed by a continuous infusion of 100 μg‐kg‐1‐h‐1of diltiazem hydrochloride. The other four dogs, were given no drugs at 25°C and served as a control group. The dogs were rewarmed, and the stimulus protocol was performed at the same temperatures as during cooling.Cooling from 37 to 25°C reduced the treshold for ventricular fibrillation in both groups. Heart rate were reduced, monophasic action potential duration at the apex and base of the heart increased from 167±5 ms to 469±17 ms and from 164±5 ms to 466±1 7 ms, respectively, when the temperature was reduced. The ventricular effective refractory period increased from 176±9 ms at 37°C to 472±15 ms at 25°C. Cooling increased QRS time on the ECG from 55±4 ms to 138±13 ms. Addition of diltiazem at 25°C did not affect the threshold for ventricular fibrillation during rewarming. Further, diltiazem at 25°C did not affect the heart rate or refractoriness. Cooling reduces the threshold for ventricular fibrillation. During hypothermia, the calcium channel blocker diltiazem does not seem to affect the threshold for ventricular fibrillation.
Are the cardiovascular actions of dopamine altered by isoflurane?
Authors: Raner C. , Biber B. , Henriksson B.‐Å. , Lundberg J. , Martner J. , Winsö O. 
Published: January 2009

Dopamine seems theoretically to be a rationale choice when adrenergic support is needed to counter undesired cardiovascular depressant effects of isoflurane. Although the cardiovascular effects of isoflurane (ISO) and exogenous dopamine (DA) are well documented, there are no reports on their pharmacological interaction. The effects of ISO 1.4% (MAC 1.0) on the cardiovascular response to exogenous DA were studied in dogs during chloralose anesthesia. Instrumentation included catheterizations of the femoral artery (for aortic pressures and heart rate, HR), the pulmonary artery (for thermodilution cardiac output, CO, and pulmonary arterial pressures) and the left ventricle (for tip‐manometer measured left ventricular end‐diastolic pressure, LVEDP). ISO per se decreased HR (‐16%), mean arterial pressure (MAP; ‐33%), CO (‐29%), left ventricular dP/dt (LV dP/dt; ‐51%), and increased pulmonary artery occlusion (PAOP; +64%) and LVEDP (+28%). Prior to ISO, DA increased MAP, CO stroke volume (SV), LV dP/dt and LV dP/dt/SAP (systolic arterial pressure) at the dose 10 ug · kg‐1· min‐1. At the dose 20 μf · kg‐1· min‐1DA, besides these effects, increased PAOP and mean pulmonary artery pressure (MPAP).During ISO, DA at the dose 10 μg · kg‐1· min‐1restored MAP, CO, and SV to pre‐ISO control levels, while LV dP/dt was increased to +96% above the pre‐ISO control level. At the dose 20 μg · kg‐1· min‐1, DA increased MAP (+33%), LV dP/dt (+172%), PAOP (+ 132%) and MPAP (+50%) above pre‐ISO control levels. The cardiac effects of DA were similar to when it was given alone. However, the increase in SVR (at the dose 20 μg · kg‐1· min‐1) and MAP (at the 10 and 20 μg · kg‐1· min‐1doses) by DA was significantly more pronounced with ISO than without ISO.In conclusion, the pressor effects of DA seem to be potentiated by ISO. DA restores systemic arterial pressure during ISO anesthesia by attenuating the cardiac depressant effects of ISO and by increasing SVR above pre‐ISO control levels.
Methylmethacrylate monomer produces direct relaxation of vascular smooth musclein vitro
Authors: Karlsson J. , Wendling W. , Chen D. , Zelinsky J. , Jeevanandam V. , Hellman S. , Carlsson C. 
Published: January 2009

Methylmethacrylate bone cement is associated with severe hypotensive reactions during surgery and anesthesia. The purpose of thisin vitrostudy was to determine if methylmethacrylate monomer could produce hypotension by acting directly on vascular smooth muscle.Segments of human saphenous vein or rabbit thoracic aorta were cut into rings. The rings were mounted in isolated tissue chambers in order to measure isometric tension development.Methylmethacrylate monomer (methylmethacrylic acid ester) produced direct relaxation of venous or aortic rings preconstricted with either potassium ion or noradrenaline. The relaxation was concentration‐dependent, occurring at concentrations from 10‐1to 10‐1M. The relaxation of rabbit aortic rings {preconstricted with noradrenaline) was unaffected by pre‐treatment with atropine, propranolol, cimetidine, indomethacin, or methylene blue. Endothelial stripping with Triton X‐100, sufficient to completely abolish acetylcholine‐induced relaxation, also had little effect on methylmethacrylate‐induced relaxation. Methylmethacrylate produced direct relaxation of rabbit aortic rings constricted with either potassium or noradrenaline in calcium‐deficient media, and inhibited subsequent calcium‐induced constriction.These results suggest that methylmethacrylate monomer may interfere with intracellular and extracellular calcium mobilization and excitation/contraction coupling in vascular smooth muscle. The direct relaxation of venous and arterial smooth muscle produced by methylmethacrylate monomer may contribute in part to the hypotension that can occur when acrylic bone cement is employed during orthopedic procedures.
Hemodynamic predictors of atrial fibrillation or flutter after coronary artery bypass grafting
Authors: Frost L. , Jacobsen C.‐J. , Christiansen E. H. , MoSlgaard H. , Pilegaard H. , Hjortholm K. , Thomsen P. E. B. 
Published: January 2009

The cumulated incidence of atrial fibrillation or flutter after coronary artery bypass grafting is 30%. The causes of these arrhythmias have not yet been sufficiently identified. We therefore undertook the present study to analyze the possible association of hemodynamic function during the various phases of coronary artery bypass grafting and the later development of atrial fibrillation/flutter.Hemodynamic function was measured with a pulmonary artery catheter in 120 consecutive patients undergoing elective coronary artery bypass surgery.Thirty‐five (29%) of the patients developed atrial fibrillation/flutter. Logistic regression analysis identified independent predictors of atrial fibrillation/flutter: After induction of general anesthesia, the relative risk (95% confidence interval) of older age was 1.09/year (1.03–1.16), and the reduction in relative risk by an increase in left ventricular stroke work was 0.96/gm (0.93–0.99). After weaning from the extracorporeal circulation the independent significant predictors were age, relative risk 1.07/year (1.01–1.13), and increased central venous pressure, relative risk 1.12/mm Hg (1.00–1.26). At the time of admission to the intensive care unit, the relative risk of age was 1.10/year (1.03–1.18), and the relative risk of an increased central venous pressure was 1.26/mm Hg (1.06–1.49). However, the best prediction model (prediction after induction of general anesthesia) only provided a median predicted probability of atrial fibrillation/flutter of 0.37 for the patients who had atrial fibrillation/flutter, and a median predicted probability of atrial fibrillation/nutter of 0.20 for the patients without these arrhythmias. We identified possible hemodynamic predictors of atrial fibrillation/flutter after coronary bypass surgery, but the use of a risk stratification for development of atrial fibrillation/flutter based on hemodynamic function cannot be recommended.
Adenosine for per‐operative blood pressure control in an infant with neuroblastoma
Authors: Selldén H. , Kogner P. , Sollevi A. 
Published: January 2009

We describe a child with a localised pelvic neuroblastoma and a hypertensive crisis during the first weeks of life due to elevated systemic norepinephrine of tumoural origin. In spite of treatment with high doses of α‐blockers, blood pressure did not respond fully and the boy had a very unstable circulation. Surgery was performed at one month of age. Adenosine, a potent short‐acting vasodilator, was used for peroperalive blood pressure control to protect the patient from an uncontrolled hypertensive crisis.During tumour manipulation the child became hypertensive with systolic pressure exceeding 130 mm Hg and adenosine infusion (100 μg‐kg‐1 · min‐1) was started with a prompt normalisation of the blood pressure. Adenosine infusion could be discontinued after tumour removal.Norepinephrine, dopamine, homovanillic acid and vanillylmandelic acid in urine were elevated preoperatively and normalised at follow up. Plasma concentrations of norepinephrine and dopamine were elevated preoperatively. Norepinephrine increased during hypertension due to tumour manipulation. Plasma neuropeptide Y increased during tumour manipulation but still within the normal range for infants.It is concluded that adenosine can be used peroperatively in children with severe hypertension and in this case no adverse effects of adenosine were noted. Furthermore, tumour synthesis and systemic release of norepinephrine, but not neuropeptide Y, contributed to hypertension in this child with neuroblastoma.
Desflurane: a new volatile anesthetic for cesarean section: Maternal and neonatal effects
Authors: Abboud T. K. , Zhu J. , Richardson M. , Da Silva E. Peres , Donovan M. 
Published: January 2009

Desflurane, a new volatile anesthetic agent with low blood/gas solubility, has recently been studied in clinical and animal trials but its use in obstetrics has not been adequately evaluated. This prospective study was undertaken to evaluate the maternal and neonatal effects of desflurane in obstetrical patients.Seventy‐five healthy parturients undergoing primary or repeat cesarean section were randomly assigned to one of three groups of 25 each, end‐tidal 3% desflurane, 6% desflurane or 0.6% enflurane, combined with 50% N2O and O2. All patients had rapid sequence induction of anesthesia with thiopentone sodium followed by succinyl‐choline for tracheal intubation. After delivery, anesthesia was maintained with reduced concentration of desflurane or enflurane with 67% N2O in O2, supplemented by butorphanol tartrate. Maternal hemodynamic parameters, blood loss and maternal awareness during surgery were monitored. Neonatal outcome was evaluated by Apgar scores, neurological and adaptive capacity scores (NACS), cord blood gas and acid‐base status, and time to sustained respiraton (TSR).Maternal blood loss did not differ significantly between the three groups and none of the patients developed intraoperative awareness. All three groups responded to psychomotor performance equally fast. Patients in all three groups developed transient hypertension and tachycardia during induction of anesthesia which returned to baseline values in approximately 5 min. Neonatal outcome was equally good in the three groups. More neonates in the 6% desflurane group had TSR>90 s compared to the 3% desflurane group (P<0.05). It is concluded that desflurane in subanesthetic concentration is a safe supplement to N2O‐O2 mixture for cesarean section with the advantage of rapid and smooth recovery. 3% desflurane in N2O‐O2 seems to be an adequate concentration for cesarean section for the healthy parturient.
Synergism between mivacurium and pancuronium in adults
Authors: Rautoma P. , Erkola O. , Meretoja O. A. 
Published: January 2009

Mivacurium could be a useful agent as a final dose of a muscle relaxant following pancuronium if only additivily exists between these agents. We examined the interaction between mivacurium and pancuronium in 70 patients (ASA I‐II) during propofol‐alfentanil‐N2O‐C2anaesthesia. Neuromuscular function was monitored by adductor pollicis EMG.Firstly we established dose‐response curves for mivacurium and pancuronium. Thereafter, 20 patients received a combination of 0.5 times the ED50doses of mivacurium and pancuronium (cMP) determined in the first part of this study. Patients were randomized to receive the cMP to the same IV‐line (n=10) or to two separate IV‐lines in opposite hands (n=10).ED50values for mivacurium and pancuronium were 57.7 and 37.1 μg kg‐1, respectively. Maximal neuromuscular block following the cMP was 91.8 ±5.0% (mean±SD). This was highly significantly different from the estimated 50% NMB if only additivity exists between mivacurium and pancuronium (P=0.0001). After the cMP, the 25 75% recovery rime was 9.4± 1.3 min and the time to train‐of‐four ratio of 0.70 was 35.8±5.4 min. There was no statistical difference in any recorded neuromuscular parameter between the two subgroups receiving mivacurium and pancuronium to the same or to opposite hands (P>040).We conclude that a significant synergism exists between mivacurium and pancuronium which may indicate that mivacurium does not produce a short‐acting NMB if given after pancuronium. We do not recommend using mivacurium together with pancuronium.
Epidural anesthesia modifies cardiovascular responses to severe hypoxia in dogs
Authors: Shibata K. , Taki Y. , Futagami A. , Yamamoto K. , Kobayashi T. 
Published: January 2009

Hypoxia is a critical and sometimes fatal complication of anesthesia. Since there is little information on the cardiovascular response to hypoxia during epidural anesthesia, we assessed the effects of epidural anesthesia on the cardiovascular response to hypoxia and on survival in dogs.We randomly assigned 36 mongrel dogs to one of three groups according to the anesthede technique used: the thoracic group (n=12) received thoracic epidural anesthesia plus general anesthesia, the thoracolumbar group (n=12) received thoracolumbar epidural anesthesia plus general anesthesia, and the control group (n=12) received general anesthesia alone. We monitored hemodynamics and plasma catecholamine concentrations and assessed survival in these groups during normocapnic hypoxia (FiO2, 0.09 for 120 min).During hypoxic challenge, PaCO2 and PaO2 values were similar in all groups. In both groups that received epidural anesthesia, heart rate, systolic and diastolic arterial pressures, and plasma epinephrine and norepine‐phrine concentrations were lower and arterial pH was greater than in the control group. There was no significant difference in survival among groups.Epidural anesthesia modified both the physiologic cardiovascular and catecholamine responses to hypoxia. Epidural anesthesia of the thoracic region did not appear to accelerate cardiac arrest, but it attenuated the development of metabolic acidosis during hypoxia.
Comparison of vascular effects of ropivacaine and lidocaine on isolated rings of human arteries
Authors: Gherardini G. , Samuelson U. , Jernbeck J. , ÅBerg B. , Sjöstrand N. 
Published: January 2009

Ropivacaine is a new local anaesthetic agent. Previous animal studies have indicated that vasoconstrictor effects are elicited by ropivacaine in vitro and subcutaneously and that it produces blanching of the skin if injected subcutaneously in humans.Lidocaine is a widely used local anaesthetic reported to exert a biphasic effect on the microvasculature with contraction at low concentrations and relaxation at high concentrations. There is a need for pharmacologic tools able to counteract local arterial vasoconstriction. In this study, the contractile effect of ropivacaine and lidocaine were investigated in vitro on isolated human arteries.Experiments were performed on 43 internal mammary artery (IMA) rings obtained from 22 patients and on 14 radial artery (RA) rings from 7 patients. The rings were mounted in organ baths and isometric contractile activity was measured. Experiments were conducted by cumulative adding ropivacaine or lidocaine (1.5X10‐5 M; 4.5X10‐5 M; 1.5X10‐4 M; 4.5X10‐4 M; 1.5X10‐3 M; 4.5X10‐3 M; 1.5X10‐2 M) to the organ baths. The endothelium was mechanically removed in 19 IMA rings and in 9 RA rings.Ropivacaine and lidocaine produced a biphasic response with contraction at low concentrations (1.5X10‐5 1.5X10‐3 M) and release of the maximal contraction at higher concentrations. No statistically significant differences in contractile or relaxing effects were seen between the two drugs. Removal of the endothelium did not significantly affect contractile activity. In this study of human mammary artery preparations, ropivacaine is not a stronger vasoconstrictor than lidocaine.
Effects of sevoflurane on respiratory activities in the phrenic nerve of decerebrate cats
Authors: Masuda A. , Haji A. , Kiriyama M. , Ito Y. , Takeda R. 
Published: January 2009

Although the depressive effect of sevoflurane on ventilation has been reported, its potency and mode of action on the neural respiratory activity is still unclear. Therefore, the effects of sevoflurane on the phrenic nerve discharge and the respiratory timing were compared with those of halothane.The efferent activity of the phrenic nerve was recorded from decerebrate, un‐anesthetized and artificially ventilated cats, and its power spectrum was calculated. The inspiratory and expiratory periods were measured. Sevoflurane and halothane of the doses of 0.5–1.5 MAC were inhaled for 15 min.With 0.5 MAC, sevoflurane decreased the total power and two dominant spectral components of the high‐frequency oscillation and medium‐frequency oscillation in the power spectrum. With the same MAC dose, halothane had a greater depressive effect in a normocapnic condition with the vagus nerves being intact. In a state of hypercapnia or after vagotomy, the effect of halothane was considerably attenuated whereas that of sevoflurane remained unaltered. Halothane increased the neural respiratory rate much more than sevoflurane in both normocapme and hypercapnic states. Vagotomy significantly weakened the effect of halothane to increase the respiratory rate but did not modify the effect of sevoflurane. With 1.0–1.5 MAC, both anesthetics severely decreased the phrenic power spectra and the potency difference became indistinct.The present findings demonstrate that sevoflurane has a weaker depressive effect on the respiratory nerve discharge and a smaller effect on the neural respiratory rate than halothane when the effects of 0.5 MAC were compared. This may be due to the lesser effect of sevoflurane on the vagal mediated and CO2‐related mechanisms which modulate the global outputs of the central respiratory control system.
Anaphylactoid skin reactions after intravenous regional anaesthesia using 0.5% prilocaine with or without preservative — a double‐blind study
Authors: Kajimoto Y. , Rosenberg M. E. , Kyttä J. , Randell T. , Tuominen M. , Reunala T. , Rosenberg P. H. 
Published: January 2009

Methylparaben, the preservative of various local anaesthetic solutions, is a potential allergen.In a double‐blind study, 0.5% prilocaine with (Citanestr̀, n=100) or without (n=100) methylparaben were compared for the occurrence of skin reactions after intravenous regional anaesthesia of the arm in surgical patients. Skin reactions were registered after the deflation of the tourniquet cuff, and intradermal tests were performed with 0.5% prilocaine, 0.1% methylparaben and saline in all patients. Seventeen patients in the Citanestr̀ group and four patients in the methylparaben‐free prilocaine group developed erythematous skin reactions in the exposed arm after deflation of the tourniquet cuff (P<0.05, between the groups). The skin symptoms disappeared within an hour and were always restricted to the region which had been anaesthetised. None of the affected patients had positive intradermal tests.The observed skin reactions are probably non‐IgE‐mediated anaphylactoid reactions in which the presence of methylparaben in the local anaesthetic solution plays a major role.
Spinal anesthesia attenuates myocardial ischemia during coronary artery spasm induced by intraaortic methacholine in rats
Authors: Mizuyama K. , Sato S. , Okubo N. , Naito H. 
Published: January 2009

Coronary artery spasm is not rare in patients with coronary artery disease, but the influence of regional anesthesia on spasm‐induced myocardial ischemia is not known. We investigated the effects of spinal anesthesia on myocardial ischemia during coronary artery spasm in rats, and compared these with the effects of an alpha‐ and beta‐adrenergic antagonist, and an alpha‐adrenergic agonist.An intraaortic catheter was inserted via the right internal carotid artery so that the tip of the catheter was placed near the coronary ostium. An intrathecal catheter was placed at lumbar level. Coronary spasm was induced by the intraaortic injection of methacholine, and we identified the thresholds of myocardial ischemia, defined as the dose of methacholine that induced ST‐segment elevation. Subsequently, the thresholds were determined after spinal anesthesia, and after the intraaortic injection of phentolamine and propranolol.The thresholds of myocardial ischemia increased significantly after intrathecal bupivacaine. In contrast, the threshold did not change after the injection of phentolamine. The thresholds increased significantly after the injection of propranolol. Methoxamine significantly decreased the threshold of ischemia.These results demonstrated that spinal anesthesia attenuated myocardial ischemia during methacholine‐induced coronary spasm. This effect was equivalent to that of propranolol.