bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metabolic effects of a low‐pressure tourniquet system compared with a high‐pressure tourniquet system in arthroscopic anterior crucial ligament reconstruction
Authors: Kokki H. , Väätäinen U. , Penttilä I. 
Published: January 2009

Background: Bloodless field is an integral part of orthopedic surgery. Use of tourniquet is associated with a risk of skeletal muscle ischemia and reperfusion injury. The purpose of this prospective, open‐randomized study was to determine if the use of a tourniquet system using low pressure, with a wide, curved cuff connected to a microprocessor pump is safer than a standard tourniquet system with a narrow, straight cuff using higher inflation pressures.Methods: Test parameters used as markers of muscular injury and anaerobic metabolism were femoral vein blood lactate, pH, pCO2, pO2, potassium, aspartate aminotransferase activity, myoglobin, creatine kinase and creatine kinase‐MM activity levels after release of tourniquet. Twenty‐six ASA I‐II patients were studied.Results: Tourniquet times varied between 30 and 144 min. Deflation of the tourniquet caused a significant release of lactate, myoglobin and potassium detected in the femoral vein blood. pCO2 increased, but pH and pO2 decreased after tourniquet deflation. There were no differences between the study groups. The tourniquet time showed a significant correlation with femoral vein lactate.Conclusion: The main finding of this study was that the metabolic changes were more pronounced with the longer tourniquet time. The results of the study did not show any difference on metabolic markers of muscular injury during the first hour afterelease of tourniquet between the two tourniquet systems.
Combined effect of patient variables on sensory level after spinal 0.5% plain bupivacaine
Authors: Pargger H. , Hampl K. F. , Aeschbach A. , Paganoni R. , Schneider M. C. 
Published: January 2009

Background: The combined effect of age, weight, height, and vertebral column length (VCL) on the distribution of isobaric 0.5% bupivacaine within the subarachnoid space is unclear. The aim of the present study was to evaluate the combined influence of these patient variables on the upper sensory level and on its predictability.Methods: In 100 patients who were above the age of 49 years, the age, weight, height, VCL, body surface (BS), and body mass index (BMI) were noted. Spinal puncture and subarachnoid drug administration were standardized. Cephalad spread of spinal anaesthesia (SA) was assessed by loss of temperature sensation and pinprick discrimination 15, 30, 60, 90, and 120 min following subarachnoid injection of 18 mg of plain 0.5% bupivacaine. Linear regression analysis was performed for each of the patient variables and the cephalad segmental spread of anaesthesia. Multiple regression analysis was used to test for combined correlation between patient variables and the sensory level of SA.Results: No linear correlation was found between the patient variables and the sersory level of anaesthesia. In contrast, multiple regression analysis revealed that age (P<0.01), weight (P<0.05), and height (P<0.01) significantly contributed to the spread of anaesthesia. A squared multiple comparison coefficient between 0.10 and 0.21, however, is an indication that the predictive value of the combined variables remained rather low.Conclusion: Multiple regression analysis revealed that age, weight, and height significantly correlated with the sensory level after subarachnoid injection of plain bupivacaine. The low predictive value suggests that patient factors other than age, weight, or height add to cephalad spread of SA.
Electrophysiological evidence for an antinociceptive effect of ketamine in the rat spinal cord
Authors: Hao J.‐X. , Sjölund B. H. , Wiesenfeld‐Hallin Z. 
Published: January 2009

Background: The dissociative anesthetic ketamine also has antinociceptive effects. The mechanism and the site of action of such effect of ketamine have been, however, elusive and controversial. The present study was conducted to examine the effect of systemically administered ketamine on spinal nociceptive transmission.Methods: We investigated and compared the effects of ketamine (0.25‐8 mg/kg) on the hamstring flexor reflex in intact, lightly anesthetized rats and spinally transected rats. The opioid receptor antagonist naloxone was used to examine the involvement of opioid receptors in the actions of ketamine. Finally, the effects of ketamine on dorsal horn neuronal activity to electrical stimulation of peripheral nerves were also studied.Results: Ketamine caused similar dose‐dependent depression of the hamstring flexor reflex recorded from spinally intact rats and from spinalized rats. Even the highest dose of ketamine failed to influence the monosynaptic reflex. The depressive effect of ketamine on the flexor reflex was not reversed by naloxone. Ketamine i.v. also exerted a relatively selective inhibition of the responses of dorsal horn wide‐dynamic‐range neurons to C‐fiber input of electrical stimulation of the plantar nerve.Conclusions: Our present results support the notion that ketamine can exert a direct antinociceptive effect in rat spinal cord. Moreover, the data indicated that the spinal antinociceptive effect of ketamine does not involve naloxone‐sensitive opioidergic mechanisms.
Epidural anesthesia and the thermoregulatory responses to hyperthermia ‐ preliminary observations in volunteer subjects
Authors: Glosten B. , Savage M. , Rooke G. A. , Brengelmann G. L. 
Published: January 2009

Background: Clinical reports associate the use of epidural anesthesia with an increase in core temperature in women in labor. We tested the hypothesis that epidural anesthesia alters thermoregulatory responses to hyperthermia in human volunteers.Methods: Each of four volunteers were studied on two days: Control and Anesthesia. On the Control day, the subject was warmed via the skin, and the core (esophageal) temperature threshold for sweating (detected on the forehead) was determined. The subject was then cooled until sweating stopped. The subject was warmed again, and a second sweating threshold was determined. The difference between the first and second sweating thresholds was noted. On the Anesthesia day, two sequential sweating threshold measurements were obtained in a similar fashion; however, a mid‐thoracic level of epidural anesthesia was established before the second sweating threshold measurement. The first and second sweating threshold differences were compared between the two study days. The presence or absence of sweating on the thigh was noted during all four warming periods.Results: Average skin temperatures were similar (about 37°C) during all four sweating threshold measurements. On the Control day, the second sweating threshold value was always slightly less than the first (average difference (mean±SD): — 0.18±0.14°C). In contrast, on the Anesthesia day, the second sweating threshold value (determined with an epidural block) was always greater than the first (average difference: +0.37±0.16°C). Epidural anesthesia, therefore, increased the sweating threshold by 0.55±0.27°C. Epidural anesthesia blocked sweating in the thigh in two of the subjects.Conclusions: An epidural block alters the thermoregulatory responses to warming by increasing the threshold for thermoregulatory sweating and, in some cases, preventing leg sweating.
Propofol and alfentanil total intravenous anaesthesia: a comparison of techniques for major thoracic surgery
Authors: Trinder T. J. , Johnston J. R. , Lowry K. G. , Phillips A. S. , Cosgrove J. 
Published: January 2009

Background: Previous work has highlighted the disadvantages of propofol as a sole agent for total intravenous anaesthesia (TIVA). This randomised study investigated three combinations of propofol and alfentanil as TIVA for major thoracic surgery.Methods: In 73 patients undergoing elective thoracic surgery, anaesthesia was conducted either with sodium thiopentone induction and inhalational maintenance (incorporating isoflurane) or with TIVA using propofol with alfentanil (by infusion at one of two rates or in incremental doses). Vital signs and recovery characteristics were recorded.Results: There were no significant differences in heart rate or blood pressure between groups during either induction or maintenance. Depth of anaesthesia was controlled satisfactorily in all groups. Recovery characteristics were similar between treatment groups, although there was a trend towards earlier orientationConclusion: Continuous infusions of propofol and alfentanil provide safe and reliable TIVA for major thoracic surgery. TIVA was found to be a satisfactory technique in more elderly patients than previously described. The higher of the two alfentanil infusion rates may result in a better combination of propofol and alfentanil with respect to recovery times than the lower.
Effects of four anticholinesterase‐anticholinergic combinations and tracheal extubation on QTc interval of the ECG, heart rate and arterial pressure
Authors: Saarnivaara L. , Simola M. 
Published: January 2009

Background: Imbalance in cardiac sympathetic tone causes prolongation of the QTc interval of the ECG. On the other hand, impairment of the parasympathetic control of the heart rate caused by anticholinesterase‐anticholinergic combinations might also affect the cardiac sympathetic tone and hence the QTc interval of the ECG. The main purpose of the present study was to compare the effects of four anticholinesterase‐anticholinergic combinations used for the antagonism of the neuromuscular block on the QTc interval of the ECG, heart rate and arterial pressure.Methods: Eighty‐four ASA class I‐II patients with a mean age of 32 to 37 yr undergoing otolaryngological surgery were randomly allocated to one of the following groups: neostigmine 40 μg/kg+glycopyrronium 8 μg/kg (Ne‐Glyc), neostigmine 40 μg/kg+atropine 20 μg/kg (Ne‐Atr), edrophonium 200 μg/ kg+atropine 300 μg (Edr‐Atr (1)), edrophonium 500 μg/ kg+atropine 7 μg/kg (Edr‐Atr (2)). QTc interval and heart rate were measured by a signal processing method based on an IBM/PC/xT‐compatible microcomputer and arterial pressure with a sphygmomanometer at 1‐min intervals up to 10 min after the injection of the drugs and immediately and 2 min after extubation. The ECG, lead II, was continuously recorded. Neuro‐muscular block was measured by a Datex relaxograph.Results: In all groups, the most pronounced increase in both QTc interval, heart rate and arterial pressure occurred 1 min after the study drugs and immediately after extubation. In all groups, the mean QTc intervals at 1 and 2 min after the study drugs and after extubation were longer than the upper limit of the normal range (440 ms). Junctional rhythm occurred in 1 to 3 patients in all other groups with the exception of the Edr‐Atr(1) group in which no cardiac arrhythmias occurred. At 1 min, the heart rate in the Ne‐Atr group was at a significantly higher level than that in the Ne‐Glyc group. From 3 to 6 min, the heart rate in the Edr‐Atr(2) group and at 3 min in the Edr‐Atr(1) group was at a lower level than the heart rate in the Ne‐Glyc group.Conclusions: On the basis of the present results, anticholinesterase‐anticholinergic combinations should be avoided in patients having a long QT interval syndrome or a prolonged QT interval from other causes. In addition, the cardiovascular stimulation caused by tracheal extubation should also be avoided in these patients.
Succinylcholine‐induced fasciculations in denevated rat muscles as measured using 31P‐NMR spectroscopy
Authors: Mizogami M. , Fujibayashi T. , Goto Y. 
Published: January 2009

Background: We have previously demonstrated by 31P nuclear magnetic resonance (NMR) that succinylcholine (SCh) induces metabolic changes in denervated muscle. To specify those changes, we attempted to inhibit them using two different kinds of drugs, dantrolene and vecuronium.Methods: Three weeks after unilateral sciatic nerve section, 75 male Wistar rats were randomly assigned to one of the following 5 groups: (1) non‐pretreated normal muscle group; (2) non‐pretreated denervated muscle group; (3) denervated muscle group pretreated with a low dose of vecuronium (0.02 mg · kg‐1); (4) denervated muscle group pretreated with a high dose of vecuronium (0.2 mg · kg‐1); (5) denervated muscle group pretreated with dantrolene (2 mg · kg‐1). The change of the inorganic phosphate/phosphocreatine (Pi/PCr) ratio of each muscle was measured by 31P‐NMR before and after SCh (1 mg · kg‐1) administration and the corresponding peak amplitude of the electromyograms (EMG) was determined.Results: The high dose of vecuronium totally inhibited SCh‐induced fasciculation on EMG (100%2%). In this group, though the Pi/PCr ratio significantly increased 10 min after SCh, the peak after 5 min disappeared. The inhibition with dantrolene was about the same order of magnitude as with the low dose of vecuronium (35%:21%). However, the increase in the Pi/PCr only lasted about 10 min, in contrast to the other drugs.Conclusion: Our findings indicate that the Pi/PCr increases 5 and 10 min after SCh, respectively, as a result of two different processes. The first peak is caused by an excessive energy consumption in response to excessive muscle contraction. This in turn triggers the second peak, caused by breakdown of glycogen, initiated by an increased Ca2+ concentration.
The discriminating power of a risk score for postoperative vomiting in adults undergoing various types of surgery
Authors: Apfel C. C. , Greim C. A. , Haubitz I. , Grundt D. , Goepfert C. , Sefrin P. , Roewer N. 
Published: January 2009

Background: Recently, we have demonstrated that the probability of postoperative vomiting (PV) following ENT surgery with inhalational anaesthetics can be predicted using a risk score. This score is based on gender, age, smoking status, history of motion sickness or postoperative nausea and vomiting and the duration of anaesthesia. Therefore, it is of interest whether this score is also accurate in predicting PV in patients undergoing different types of surgery.Methods: Inpatients scheduled for bone, vascular, general or eye surgery were included in a prospective survey for PV over 24 h. Data of 1091 patients were analyzed, of which 542 were used for the validation of the previously constructed risk score (Score I). The data of the remaining 549 patients were used to evaluate the risk factors that contribute to PV in this setting and to develop a new score (Score II). The discriminating power of both scores to predict PV was tested in the validation set (n=542) and compared by calculating the area under the receiver operating characteristic (ROC) curves.Results: The area under the ROC curve of Score I was 0.77 (SD 0.024). Risk factors for PV in the evaluation set were female gender, young age, history of motion sickness or postoperative nausea and vomiting and the type of surgery. The area under the curve of Score II was 0.75 (SD 0.026) and was not significantly different from Score I (P=0.57).Conclusion: Score I was accurate in predicting PV in patients after most types of surgery with volatile anaesthetics, which suggests that this score might be useful for other centres as well.
Effects of esmolol on haemodynamic response to CO2 pneumoperitoneum for laparoscopic surgery
Authors: Koivusalo A.‐M. , Scheinin M. , Tikkanen I. , Yli‐Suomu T. , Ristkari S. , Laakso J. , Lindgren L. 
Published: January 2009

Background: Carbon dioxide (CO2) pneumoperitoneum for laparoscopic surgery increases arterial pressures, systemic vascular resistance and heart rate and decreases urine output.Methods: In this double‐blind randomized study esmolol, an ultrashort‐acting β1‐adrenoceptor antagonist was compared with physiological saline (control) in 28 patients undergoing laparoscopic surgery in standardized 1 MAC isoflurane anaesthesia. Alfentanil infusion was used to prevent the increase of mean arterial pressure more than 25% from baseline.Results: Esmolol effectively prevented the pressor response to induction and maintenance of CO2 pneumoperitoneum. Significantly (P<0.001) less alfentanil was needed in the esmolol group than in the control group. Urine output was higher (P<0.05) and plasma renin activity (P<0.01) and urine N‐acetyl‐β‐D‐glucosaminidase levels lower in the esmolol group when compared with the control group.Conclusions: Esmolol blunts the pressor response to induction and maintenance of pneumoperitoneum and may protect against renal ischaemia during pneumoperitoneum.
Influence of premedication with diazepam or morphine on the induction dose of eltanolone
Authors: Czuchwicki A. , Plummer J. L. , Love D. R. , Owen H. , Ilsley A. H. 
Published: January 2009

Background: This study examined the influence of premedication with morphine or diazepam on the dose of eltanolone, a steroidal intravenous anaesthetic agent, required to induce anaesthesia.Methods: Two hundred and sixteen patients, aged 18 to 65 years, were randomly assigned to receive premedication with diazepam 10 mg orally, morphine 10 mg intramuscularly, or placebo. The double‐dummy technique was used to maintain blinding. Eltanolone 0.16‐0.75 mg·kg‐1 was given intravenously over 20 s. At the commencement of injection patients were instructed to begin counting; if the patient ceased counting within 120 s and failed to respond to commands to continue, anaesthesia was considered to have been induced. The dose required to anaesthetise 50% of patients (ED50) was determined by logistic regression.Results: The ED50 (95% confidence interval) of eltanolone in patients who received placebo premedication was 0.31 (0.27‐0.34) mg · kg‐1. It was reduced slightly and nonsignificantly by premedication with diazepam, to 0.27 (0.24‐0.30) mg · kg‐1, or morphine, to 0.26 (0.23‐0.29) mg · kg‐1. Involuntary movement occurred in 65% of placebo premedicated patients. Its incidence was not significantly reduced by diazepam (57%), but was significantly (P<0.001) reduced by morphine (37%). Morphine premedication was, however, associated with a significant (P<0.01) increase in the incidence of apnoea (21%) compared to placebo premedicated patients (4%).Conclusion: Premedication with diazepam or morphine had little influence on the dose of eltanolone required to induce anaesthesia.
The inflammatory cytokine response after autotransfusion of shed mediastinal blood
Authors: Schmidt H. , Bendtzen K. , Mortensen P. E. 
Published: January 2009

Background: The inflammatory response in patients undergoing cardiac surgery with cardiopulmonary bypass is well known and increased levels of inflammatory cytokines have been shown. High levels of cytokines have been reported in blood drained from the surgical field. The present study aimed to elucidate whether autotransfusion of shed mediastinal blood in itself causes increased cytokine levels in coronary artery bypass graft (CABG) patients.Methods: A prospective, randomized controlled study was performed in 23 patients having elective uncomplicated CABG. Autotransfusion of shed mediastinal blood was done every hour for 18 h in group I. In group II, the shed mediastinal blood was accumulated for 4 h in the cardiotomy reservoir and then autotransfused every hour for the next 14 h. Plasma levels of tumour necrosis factor‐α (TNFα) and interleukin (IL)‐1α, IL‐1β, IL‐6 were measured. In vitro study of cytokine production was performed with or without stimulation (phytohaemagglutinin (PHA) and Escherichia coli (E. coli) lipopolysaccharide (LPS)).Results: We found high levels of IL‐6 in the shed mediastinal blood. However, autotransfusion of shed mediastinal blood did not lead to increased level of cytokines (TNFα, IL‐1α, IL‐1β and IL‐6) in plasma in group I nor in group II. In vitro study showed activation of the leucocytes in the shed mediastinal blood with a significantly increased production of TNFα and IL‐6 both in the stimulated and non‐stimulated samples.Conclusion: Shed mediastinal blood contains high levels of IL‐6. However, autotransfusion of shed mediastinal does not cause measurable elevations in plasma levels of IL‐6. In vitro study shows that autotransfusion activates leucocytes, which may enhance production of inflammatory cytokines.
Dose‐dependent suppression of the neutrophil respiratory burst by lidocaine
Authors: Hyvönen P. M. , Kowolik M. J. 
Published: January 2009

Background: Oxygen radical production is thought to be fundamental to the pathogenesis of post‐ischaemic reperfusion injury which is routinely managed with lidocaine. Attention has, therefore, focused on the suppression of the neutrophil respiratory burst with a therapeutic endpoint. The widest application of lidocaine remains in local analgesia.Methods: A standard chemiluminescence technique was used to assess the human neutrophil leukocyte response to increasing doses of lidocaine in the presence or absence of particulate hydroxyapatite.Results: No reduction of oxygen radical production was seen at the drug concentration of 1 mg/ml. A clear, concentration‐dependent inhibition was seen at 2 mg/ml, 3 mg/ml, 4 mg/ml and 8 mg/ml concentrations. These drug concentrations may be reached at or near the site of injection in local anaesthetic use.Conclusion: Lidocaine showed profound anti‐inflammatory action in this experimental system. Controlled studies in the clinical setting would identify the optimal analgesic and anti‐inflammatory dosage, whilst preserving host defence without compromising tissue repair.
Comparison of transarterial and multiple nerve stimulation techniques for an initial axillary block by 45 mL of mepivacaine 1% with adrenaline
Authors: Koscielniak‐Nielsen Z. J. , Hesselbjerg L. , Fejlberg V. 
Published: January 2009

Background: The single‐injection axillary block is rapidly performed but gives unpredictable results. Axillary block by multiple nerve stimulation technique (MNS) gives better results, but takes longer to perform. Transarterial (TA) injections of high doses of local anaesthetics are very successful. This double‐blind study compared both block effectiveness and anaesthesiologic time consumption in 100 patients, having an axillary block by either TA or MNS techniques.Methods: 45 mL of 1% mepivacaine with adrenaline 5 μg/mL was used in each patient. Five mL was injected subcutaneously. In the TA group, 20 mL was injected deep to, and 20 mL superficial to the axillary artery. In the MNS group, four terminal motor nerves were electrolocated in the axilla, and injected with 10 mL each. Analgesia was assessed every 10 min and when needed supplemented after 30 min. The block was considered successful when analgesia was present in all sensory nerve areas distal to the elbow.Results: MNS group required 10δ2 min (meanδ1 SD) for the initial block performance compared with 7δ2 min for TA group, P<0.001. Latency of the initial block was shorter and the frequency of supplemental analgesia lower in the MNS group (mean 17 min and 12%), than in the TA group (25 min and 38%, respectively), P<0.001. All incomplete blocks were successfully supplemented by electrolocating the unblocked nerves. However, the total time to obtain 100% success rate was shorter in the MNS group (30 min), than in the TA group (38 min), P<0.001. The adverse effects (accidental intravascular injections and axillary haematomas) were fewer in the MNS group.Conclusion: In the hands of anaesthetists experienced in nerve electrolocation, the MNS technique of an initial axillary block by four separate injections of 10 mL of mepivacaine produces faster and more extensive block than the TA technique by two separate injections of 20 mL. Hence, the MNS technique requires fewer supplementary blocks and results in faster patient readiness for surgery than the TA technique.