bluuebunny/crossref_metadata_2025_split huggingface dataset:
The haemodynamic effects of rocuronium and vecuronium are different under balanced anaesthesia
Authors: STEVENS J. B. , HECKER R. B. , TALBOT J. C. , WALKER S. C. 
Published: January 2009

Background: Rocuronium has been reported to have minimal haemodynamic effects. However, this conclusion has been drawn primarily from investigations conducted under narcotic‐based anaesthesia. This study was designed to evaluate the cardiovascular effects of rocuronium under isoflurane/N20/fentanyl anaesthesia and to compare rocuronium's haemodynamic effects to those of vecuronium and pancuronium.Methods: Anaesthesia was induced with fentanyl 2 μg/kg, thiopentone 4 mg/kg, and suxamethonium 0.5 mg/kg in 75 ASA I or II patients. After tracheal intubation, anaesthesia was maintained with isoflurane 0.5% and N20 50% in oxygen. Five min after intubation (baseline), patients randomly received either vecuronium 100 μg/kg, rocuronium 600 μg/kg, rocuronium 900 μg/kg, rocuronium 1200 μg/kg, or pancuronium 140 μg/kg. One min after administration of muscle relaxant, mean arterial pressure (MAP) and heart rate (HR) were recorded and were subsequently measured at 1‐min intervals for the next 4 min.Results: HR decreased significantly (P<0.05) at all times compared to baseline in patients receiving vecuronium. HR significantly (P < 0.05) increased in those receiving rocuronium 1200 μg/kg or pancuronium. Patients who received vecuronium had a sigruficant (P< 0.05) decrease in MAP at all times compared to baseline. Comparing results between groups, patients who received rocuronium or pancuronium had significantly (P < 0.05) higher MAP compared to those administered vecuronium.Conclusion: The haemodynamic effects of rocuronium and vecuronium are different under balanced anaesthesia. Rocuronium may attenuate the fall in MAP that often occurs under balanced anaesthesia without surgical stimulation.
Tramadol in the treatment of postanesthetic shivering
Authors: WITTE J. DE , DELOOF T. , VEYLDER J. DE , HOUSMANS P. R. 
Published: January 2009

Background: As an inhibitor of the reuptake of serotonin and norepinephrine in the spinal cord, the mechanism of action of tramadol resembles that of nefopam, which has been used in the treatment of postanesthetic shivering.Methods: In a randomized, placebo‐controlled, double‐blind study, we assessed the effects of tramadol (0.5 mgskg‐1, 1 mg kg‐1 and 2 mg kg‐1 i.v.) or normal saline on shivering after a standardized general anesthesia in 40 adult patients, ASA physical status I or II (group l), and in 64 adult patients regardless of the foregoing general anesthesia and ASA physical status (group 2).Results: Tramadol l mg. kg‐1 or more abolished shivering completely 5 min after treatment in all patients of groups 1 and 2. In group 1, the three dosages of tramadol were not statistically different in lowering the severity and prevalence of postanes thetic shivering. Tramadol 0.5 mg kg‐1 was significantly slower than tramadol l or 2 mg. kg‐1 in tempering the severity as well as lowering the prevalence of postanesthetic shivering in group 2.Conclusion: Tramadol's distinct features in the treatment of shivering reside in its high safety profile and weak sedative properties, particularly in patients with poor cardiorespiratory reserve, in outpatients and on recurrence of shivering.
Magnesium ‐ a profibrillatory or antifibrillatory drug depending on plasma concentration, heart rate and myocardial perfusion
Authors: AUPET J. F. , FREYSZ M. , FAUCON G. , LOUFOUA‐MOUNDANGA J. , COQUELIN H. , TIMOM Q. 
Published: January 2009

Background: The opinions on the efficacy of magnesium as an antiarrhythmic drug vary considerably. The action of magnesium on vulnerability to fibrillation was therefore investigated in anaesthetized, open‐chest pigs under different conditions as regards plasma concentration, heart rate and myocardial perfusion.Methods: Vulnerability to fibrillation was assessed by electrical fibrillation threshold (EFT), measured with 100‐ms duration diastolic impulses. These stimuli were delivered to the heart normally perfused, at a usual (90 and 120 beats/min) or accelerated (180 beats/min) rate. Vulnerability to fibrillation was also assessed at the high rate (180 beats/min) in the heart made isch‐aemic by complete occlusion of the left anterior descending coronary artery near its origin. EFT was then measured at the end of occlusion periods which were of increasing duration (30, 60, 90, 120 s). Monophasic action potential (MAP) duration, intraventricular conduction time, left ventricular dP/dt max (LVdP/dt max) and mean blood pressure were concurrently measured.Results: In the absence of ischaemia, 5 μmol kg‐1. min‐1 magnesium i.v. infusion, which raised plasma concentration to 1.78±0.14 mmol/L, lowered EFT, measured at the rate of 116 beats/min, from 14.0±1.1 to 6.8±1.0 mA (P<0.001), without significant variation of the other parameters. Administered as previously or in a markedly higher dose (400 μmol kg‐1 loading dose and 10 pmol kg‐1 min‐1 infusion) which raised plasma concentration up to 4.84±0.52 mmol/L, magnesium significantly influenced neither EFT nor MAP duration, reduced by the high rate (180 beats/min) to 6.2–6.7 mA and 212–220 ms respectively. Under the same conditions, at the same 180 beats/min rate, ischaemia brings about a fall of EFT, from 6.9 down to nearly 0 mA, with occurrence of fibrillation, in approximately 120 s. Magnesium failed to slow this fall and to delay the onset of fibrillation. In contrast, within the minutes following the end of occlusion, magnesium increased EFT to a great extent (from 7.1 ± 20.4 to 13.5±0.7 mA, P <0.001), with a significant prolongation of MAP duration (212±6 to 234±8 ms, P < 0.01).Conclusion: Magnesium may develop profibrillatory or antifibrillatory effects depending on plasma concentration, heart rate and myocardial perfusion.
A tube in the pharynx for emergency ventilation
Authors: BUND M. , WALZ R. , LOBBES W. , SEITZ W. 
Published: January 2009

Background:If the endotracheal placement of a nasal advanced tube fails, ventilation via this tube could bridge the time until a fibreoptic bronchoscope is available. This study investigates the efficiency of ventilation via a tube resting with its tip in the pharynx near the glottis.Methods: In 20 patients respiratory data during ventilation via a pharyngeally placed tube were recorded by means of pulse oximetry, capnometry and side‐stream spirometry. Results were compared with those measured previously in the same patients during conventional facemask ventilation.Results: Oxygen saturation and end‐tidal carbon dioxide concentration remained unchanged using ventilation via facemask (SO2 98.5±0.9%, FECO2 4.5±0.7 vol%) or pharyngeal tube (SO2 98.6±0.7%, FECO2 4.8±0.4 vol%). No significant differences were found between the two groups with regard to peak airway pressure, tidal volume leakage, compliance and resistance of the respiratory system.Conclusions: Our results suggest an effective ventilation and oxygenation via a tube placed with its tip in the pharynx. This technique may be helpful during difficult and prolonged nasal intubation.
Blockade of ATP‐sensitive K+ channel abolishes the anti‐ischemic effects of isoflurane in dog hearts
Authors: NAKAYAMA M. , FUJITA S. , KANAYA N. , TSUCHIDA H. , NAMIKI A. 
Published: January 2009

Background:Although isoflurane is reported to have a protective effect against ischemic damage on the myocardium, the mechanisms of this effect are not clear. Activation of adenosine triphosphate sensitive potassium (KATP) channels is indicated to protect myocardium during ischemia. Thus, it was hypothesized that if isoflurane could activate KATP channels, blockade of KATP channels would decrease its cardioprotective effect.Methods:Mongrel dogs, anesthetized with morphine, urethane, and chloralose, were subjected to 15 min of left anterior descending coronary artery occlusion followed by 60 min reperfusion. The dogs were divided into three groups: the control group (n=8), IS0 group (n=8) and ISOGC group (n=8). In the IS0 and ISOGC groups, 1 MAC of isoflurane was administrated during ischemia and reperfusion. In the ISOGC group, 0.3 mg/ kg of glibenclamide, the KATP channel blocker, was given 45 min before ischemia. Full‐thickness samples of myocardium were obtained and the concentrations of adenosine monophosphate, adenosine diphosphate, adenosine triphosphate (ATP), creatine phosphate and lactate in the endocardial portion of the myocardium were measured.Results:The ischemia‐reperfusion caused a 25.4% and 27.6% reduction of myocardial ATP in the control and ISOGC groups, respectively. In contrast, the IS0 group showed only 11.0% reduction of AT, which was significantly lower compared to the other groups (P< 0.01).Conclusions:Our results shows that blockade of the KATP channel abolishes cardioprotective effects of isoflurane in myocardial ischemia‐reperfusion. The KATP channel may play a role in the ATP‐sparing effect of isoflurane.
Intrathecal morphine for post‐stemotomy pain in patients with myasthenia gravis: effects on respiratory function
Authors: NILSSON E. , PERTTUNEN K. , KALSO E. 
Published: January 2009

Background: Thymectomy can induce a remission or at least an improvement in myasthenia gravis (MG) patients. After sternotomy MG patients with compromised muscle strength need an excellent postoperative pain relief. This study was designed to evaluate the efficacy of intrathecal morphine (ITM) on ventilatory function among MG patients undergoing trans‐sternal thymectomy, when intravenous morphine served as control.Methods: Twenty consecutive MG patients were randomised to receive either morphine (10 μg/kg) intrathecally at induction or intravenous morphine (30 μg/kg) with a patient‐controlled analgesia (PCA) device. Anaesthesia was standardised. Forced vital capacity (FVC), forced expiratory volume in 1 s (FEVl), respiratory rate, oxygen saturation, arterial blood gases, pain intensity and morphine consumption were assessed during 48 hours.Results: The mean age of the patients was 35±3.4 years and the mean duration of the disease 1.9±0.5 years. According to Osserman's classification 70% of the patients belonged to Class IIA and 30% to Class IIB. ITM restored ventilatory function significantly better than iv PCA morphine. FVC recovered to 60% and FEV1 to 57% of the baseline values in the ITM group compared with 32% (P < 0.05) and 37% in the PCA morphine group, respectively. Postpuncture headache occurred in 4/10 patients.Conclusion: Intrathecal morphine provided effective postoperative analgesia and significantly improved ventilatory function when compared with intravenous morphine.
Motor power pharmacodynamics of subarachnoid hyperbaric 5% lidocaine in the sitting position
Authors: RUSHMER J. , MILES W. , JONES R. D. M. , HO J. Y. W. , CHEUNG C. K. W. , CHAN S. S. C. 
Published: January 2009

Background:Repetitive dynamometric measurement using a plantar flexion power device (PFPD) provides detailed data describing the onset and offset of motor block following spinal administration of lidocaine. The aim of this study was to evaluate administration of two doses of spinal lidocaine in the sitting position to determine whether our dynamometric model produces data consistent with our current understanding of the pharmacokinetics of subarachnoid, hyperbaric, 5% lidocaine.Methods:Twenty male patients (54 to 80 yr) undergoing cystos‐copy received spinal anaesthesia with either 75 mg (n=10) or 100 mg of hyperbaric lidocaine 5%, in the sitting position, under standardised conditions. Plantar flexion muscle power was recorded during onset and offset of anaesthesia using a load cell interfaced with a computer (PFPD).Result:Onset of paralysis following spinal block in the sitting position was rapid and complete with motor power declining exponentially to 5% of preoperative values by 8.5 min in all patients. There was no difference in decay or recovery of plantar flexion motor power data between dosage groups in the sitting position. Measurement using the PFPD shows that onset of motor paralysis is described by an exponential decay and that motor recovery occurs at a fixed rate. Extent of block to cold and pinprick was similar in both dosage groups in the sitting position (median T4).Conclusion:This study shows that in the sitting position, doses less than 75 mg of 5% hyperbaric lidocaine are required to significantly improve ambulatory times.
The use of central regional anesthesia techniques in Sweden: results of a nation‐wide survey
Authors: HOLMSTRÖM B. , RAWAL N. , ARNÉR S. 
Published: January 2009

Background: Epidural and subarachnoid anesthesia are well established central regional techniques for surgical anesthesia. TWO additional techniques, combined spinal epidural (CSE) block and continuous spinal anesthesia (CSA), have recently become popular. However, data on nation‐wide use of central regional blocks are not available.Method: With the aims to survey the use of central regional techniques, to evaluate the risk of complications to central regional blocks and to document the use of continuous epidural techniques for postoperative pain management in Sweden during 1993, a questionnaire was mailed to all 105 Swedish anesthesiology departments.Results: Questionnaires were returned by 62 departments, representing all categories of Swedish hospitals. Central regional blocks were used for surgical anesthesia in 2040% of reported surgical procedures. Subarachnoid anesthesia was the main technique for orthopedic surgery on the lower limb, elective cesarean section and transurethral resection of the prostate. Epidural block was used for orthopedic and vascular surgery. CSE block was used by 42 departments and CSA by 21 departments. Postoperative epidural analgesia was used by 59 departments, most commonly with continuous infusion of local anesthestics and/or epidural bolusdoses of morphine. Nineteen neurological sequelae were reported after epidural (n=7) and subarachnoid (n=12) blocks. Routines for registration of complications varied greatly.Conclusions: Subarachnoid block was preferred for shorter surgical procedures (<60 min), whereas epidural and CSE blocks were chosen when severe postoperative pain could be anticipated, as continuous epidural analgesia was well established for postoperative pain management. Improved routines for registration of complications to central regional blocks are needed.
Intravenous phentolamine test ‐ an aid in the evaluation of patients with persistent pain after low‐back surgery?
Authors: SÖRENSEN J. , BENGTSSON M. 
Published: January 2009

Background: Persistent pain following surgery in the treatment of chronic low‐back pain patients is still relatively frequent. Most of these patients with persistent pain have clinical signs of neuropathic pain. The neuropathic pain might be sympathetically maintained pain (SMP) or sympathetically independent pain (SIP). Systemic administration of phentolamine, a competitive alpha‐adrenergic antagonist, has been used as a diagnostic tool to identify patients with SMP.Methods: Thirty‐seven patients with persistent pain after low‐back surgery (lumbar laminectomy, with or without discectomi, or a posterior fusion, with or without decompression) received intravenous phentolamine (0.5 mg/kg over 30 min) in a single‐blind, placebo‐controlled manner. Prior to this infusion the patients were classified clinically into different pain groups based on physical examination and imaging findings. An opioid epi‐dural test blockade was used as a control.Results: Clinical classification divided the patients into nocicep‐tive pain (n=7), neuropathic pain (n=22) and mixed pain (n= 8). In the phentolamine test there were only one responder, 34 non‐responders and 2 patients were placebo‐responders. In the control epidural blockade there were 11 non‐responders, 23 fen‐tanyl/local anaesthetic‐responders and 3 placebo‐responders. Conclusions: SMP is either an uncommon cause of persistent pain in this type of failed back surgery patients or the phentolamine test, as we performed it, was unable to identify SMP.
Segmental effects on motor function following different intrathecal receptor agonists and antagonists in rabbits
Authors: BORGBJERG F. M. , FRIGAST C. 
Published: January 2009

Background:The occurrence of motor impairment after intrathecal drug administration is infrequently reported in the literature and the methods of determining motor function vary.Methods:Motor function was examined in rabbits after a wide dose range of a variety of intrathecally administered opioid agonists, α‐adrenergic agonists, non‐competitive NMDA antagonists, a benzodiazepine agonist, a sigma agonist, paracetamol, isotonic and acidified saline. The opioids, sigma agonist and NMDA antagonists were additionally examined following pre‐treatment with naloxone. The opioid antagonists naltrindole and MR2266 (δ‐ and K‐opioid receptor antagonists, respectively) were administered before the δ agonist and the K agonist. The δ adrenergic antagonist yohimbine was given before administration of dexmedetomidine and xylazine. Motor function was evaluated by a five‐point scale of motor impairment ranging from normal function to total paralysis of the hindlegs.Results:DPDPE (δ agonist), paracetamol, naloxone, naltrindole, yohimbine, isotonic and acidified saline did not affect motor function. MR2266 produced minor motor impairment. The α‐adrenergic agonist dexmedetomidine reduced motor function slightly and dose independently. The remaining compounds affected motor function in a dose‐dependent fashion. High doses of morphine produced hypersensitivity and myoclonus. An irreversible paralysis of the hindlegs was observed following intrathecal administration of the sigma agonist SKF10047 in high doses. Naloxone and MR2266 attenuated the effects of U50488H (K agonist).Conclusion:The present results reveal a dose‐dependent reduction in motor function after intrathecal administration of some of the investigated compounds. The mechanisms behind these effects appear to be multifactorial.
Bupivacaine does not suppress cardiac sympathetic nerve activity during halothane anesthesia in the cat
Authors: NISHIKAWA K. , TERAI T. , MONMOTO O. , YUKIOKA H. , ASADA A. 
Published: January 2009

Background:The finding that IV lidocaine suppresses cardiac sympathetic nerve activity during 1 MAC halothane, but not during 2 MAC or 3 MAC halothane, suggests that the neurally mediated circulatory effects of IV local anesthetics may vary with background autonomic activity. This study aimed to compare the effects of IV lidocaine and bupivacaine on cardiac sympathetic nerve activity (CSNA) during normal and high levels of CSNA.Methods:Cats were anesthetized with halothane and allocated to three groups. In groups I‐L and I‐B, sympathetic hyperactivity was induced by electrical stimulation of the posterior hypothala‐mus. CSNA, heart rate and mean arterial pressure were then measured before and after administration of lidocaine 2 mgkg BW‐lIV (Group I‐L, n=7) or bupivacaine 0.5 mgkg BW‐1IV (Group I‐B, n=7) during 1% halothane anesthesia. In Group II (n=7), following administration of bupivacaine 0.5 mgkg BW‐1IV, CSNA, sinus cycle length (SCL), and subintervals of atrio‐ventricular conduction time (A‐H, H‐V, and H‐S) at pacing were measured during O.8%, 1.6% and 2.4% halothane anesthesia without sympathetic hyperactivity.Results:Lidocaine suppressed CSNA hyperactivity and tachycardia significantly in Group I‐L, but bupivacaine did not do so in Group I‐B. In Group 11, bupivacaine did not affect CSNA at any concentrations of halothane, but lengthened SCL, A‐H, H‐V and H‐S intervals significantly at each concentration of halothane.Conclusions:We conclude that IV bupivacaine, unlike IV lidocaine, does not suppress CSNA during either normal or high CSNA under halothane anesthesia although IV bupivacaine has stronger depressive effects on cardiac conduction than does IV lidocaine during deep halothane anesthesia.
The effect of patient positioning on dynamic lung compliance
Authors: TANSKANEN P. , KYNA J. , RANDELL T. 
Published: January 2009

Background: Side‐stream spirometry offers a non‐invasive method to monitor continuously respiratory mechanics in intubated patients. We studied the effects of different positions on dynamic lung compliance during anaesthesia.Methods: The study consisted of 56 patients, operated in supine, prone, kneeling or lateral park‐bench position. Dynamic lung compliance and inspiratory peak pressure were recorded after induction of anaesthesia, 15 min and 1 h after posturing the patient.Results: The first measured compliances were comparable in all groups. The compliance in the lateral and the prone positions was significantly lower than in the supine position at 15 min (P < 0.01) and 1 h (P < 0.001) after the posture change. The peak inspiratory pressure was significantly lower in the kneeling position than in the other groups (P < 0.01 at the first measurement, P < 0.001 at the later measurements). No correlation was found between body mass index and compliance.Conclusion: We found that dynamic lung compliance decreased significantly upon change of posture from supine to lateral or prone position, whereas in the kneeling position no change in compliance was observed. We suggest that the kneeling position might be preferable to the prone position.
The effect of acute normovolemic hemodilution on homologous blood requirements and total estimated red blood cell volume lost
Authors: KAHRAMAN S. , ALTUNKAYA H. , ÇELEBÍOǧLU B. , KANBAK M. , PASLAOLU ÎI. , ERDEM K. 
Published: January 2009

Background:Acute normovolemic hernodilution combined with retransfusion is one of the various techniques proposed to avoid homologous blood transfusion in cardiac surgery. The purpose of the present paper is to study the effect of the volume of autologous blood collected pre‐cardiopulmonary bypass (CPB) on homologous blood requirements and total estimated red blood cell (RBC) volume lost in coronary artery bypass grafting (CABG) surgery.Methods:Following induction of anesthesia, sequestration of one (5–8 ml/kg; Group I, n=14) or two units (12–15 ml/kg; Group 11, n=14) of fresh autologous blood was performed under electrocardiographic and hernodynamic control. Group III (n= 14) was designated as the control group. Autologous blood was reinfused at the conclusion of CPB.Results: The use of homologous blood in the study groups was significantly less than in the control group. High‐volume phlebotomy did not make a significant difference in the requirement of the homologous blood, while causing a mild increase in the total estimated RBC volume lost. No significant differences could be demonstrated in preoperative, post‐CPB and discharge hematocrit levels and postoperative blood drainage between the groups.Conclusion:Acute intraoperative hemodilution with high‐ and low‐volume phlebotomy reduced the homologous blood requirements similarly regardless of the amount of phlebotomy.