bluuebunny/crossref_metadata_2025_split huggingface dataset:
Auditory evoked potential monitoring with the AAITM‐index during spinal surgery: decreased desflurane consumption
Authors: Määttänen H. , Anderson R. , Uusijärvi J. , Jakobsson J. 
Published: March 2003

Background: The auditory evoked potential (AEP) is sensitive to the depth of anesthesia. The A‐line monitor is a novel device that processes the amplitude and latency of the AEP during the mid‐latency time window to provide a simple numerical index, the AAI™‐index. The hypothesis of the present study was that titration of anesthetic depth (desflurane) by means of the AAI™‐index could decrease the consumption of the main anesthetic and shorten emergence times.Methods: Thirty ASA I–II patients scheduled for elective open spine surgery under general anesthesia were randomly allocated to two groups. Group I (n=15), the main anesthetic, desflurane, was titrated with a target AAI™‐index of 20±5. Group II (n=15), desflurane was titrated according to routine clinical signs, including heart rate, blood pressure, sweating and tears. No fixed MAC‐multiple was sought. The primary study variable was desflurane consumption; and secondary study variables were time to extubation and orientation.Results: All patients had an uncomplicated course and no patients showed signs of awareness or had any recall postoperatively. AAI™‐index guidance reduced desflurane consumption by 29% and improved emergence. Time until extubation and orientation and ability to state name and date of birth was significantly shortened among AAI™‐index titrated patients.Conclusion: Titrating depth of desflurane anesthesia using AAI™‐index guidance decreased main anesthetic consumption and improved emergence during spine surgery.
Bilateral continuous paravertebral catheters for reduction mammoplasty
Authors: Buckenmaier C. C. , Steele S. M. , Nielsen K. C. , Martin A. H. , Klein S. M. 
Published: March 2003

Surgical procedures of the breast can result in significant postoperative pain. Paravertebral nerve blocks have been used successfully in the management of analgesia after breast surgery but are limited by a single injection. This report describes the use of bilateral paravertebral catheters to provide extended analgesia for reduction mammoplasty.A 48‐year‐old female underwent bilateral paravertebral catheter placement at thoracic level 3 and local anesthetic injections followed by general anesthesia for elective reduction mammoplasty. She reported no pain following the operation and required no supplemental opioids for pain management during her overnight recovery.This case demonstrates a method for extended bilateral thoracic analgesia. The technique may offer an alternative to traditional outpatient analgesics for reduction mammoplasty.
Effects of prone and supine posture on cardiopulmonary function after experimental chlorine gas lung injury
Authors: Wang J. , Abu‐Zidan F. M. , Walther S. M. 
Published: March 2003

Background: Chlorine gas may induce severe acute lung injury. Improvement of pulmonary gas exchange in patients and animals with acute lung injury nursed in the prone position was observed in recent years. The purpose of this study was to evaluate the effects of prone and supine positions on pulmonary and cardiovascular functions following experimental chlorine gas lung injury.Methods: Twenty anesthetized and mechanically ventilated pigs were exposed to chlorine gas (400 p.p.m. in air) for 20 min in the supine position, then assigned randomly to ventilation in the supine or prone positions (n=10 in each group). Hemodynamics, gas exchange, lung mechanics and oxygen transport were evaluated for 5 h.Results: All animals showed severe pulmonary dysfunction immediately after chlorine gassing with a threefold increase in pulmonary vascular resistance index, a drop in arterial oxygenation (12.3±1.3 kPa to 5.4±0.7 kPa) and a fall in lung‐thorax compliance (22±1 ml cmH2O−1 to 8±2 ml cmH2O−1). Venous admixture (Qs/Qt) improved in animals in the prone position while there was no change in the supine position (prone 32±11% vs. supine 42±9% at 5 h,P<0.05). Lung‐thorax compliance improved significantly with time in the prone group only (P<0.01). Oxygen delivery increased significantly in prone animals compared with animals nursed in the supine posture (P<0.001).Conclusion: Immediate prone positioning after chlorine gas injury not only inhibited deterioration of gas exchange but was also associated with improved pulmonary function and oxygen transport.
Acceleromyography of the orbicularis oculi muscle I: significance of the electrode position
Authors: Gätke M. R. , Larsen P. B. , Engbæk J. , Fredensborg B. B. , Berg H. , Viby‐Mogensen J. 
Published: March 2003

Background: This study aimed to establish the best position of the stimulating electrodes for facial nerve stimulation during acceleromyographic monitoring from the orbital part of the orbicularis oculi muscle.Methods: In 59 anaesthetised patients, an acceleration transducer was positioned over the middle of the eyebrow. In 47 patients, supramaximal train‐of‐four (TOF) stimulation was established for four electrode pairs with different positions along the facial nerve and behind the ear. The electrode pair with the lowest, the intermediate, and the highest supramaximal stimulating current based on first response (T1) in TOF was found in each patient. A possible response from direct muscle stimulation was evaluated during complete vecuronium block. In 12 patients, supramaximal stimulation was established using a stimulation sequence different from the one used in the first part of the study.Results: The best positions for the stimulating electrodes were either with both electrodes just lateral to the eye, or with one electrode lateral to the eye and one in front of the ear. In most patients, supramaximal stimulation was obtained at these positions at 20–60 mA. However, in 10–21% of the patients, supramaximal stimulation could not be obtained. During complete block, 1–4 responses with a twitch height of 3–11% were recorded in 80% of the patients.Conclusion: The best placements of the stimulation electrodes are either just lateral to the eye or along the zygomatic arch. However, supramaximal stimulation may often not be obtainable, and activation of other facial muscles may be a confounding factor that may impede correct evaluation of the degree of neuromuscular block.
Acceleromyography of the orbicularis oculi muscle II: comparing the orbicularis oculi and adductor pollicis muscles
Authors: Larsen P. B. , Gätke M. R. , Fredensborg B. B. , Berg H. , Engbæk J. , Viby‐Mogensen J. 
Published: March 2003

Background: The orbicularis oculi (OO) muscle has been recommended for neuromuscular monitoring when the adductor pollicis (AP) muscle is not available. We investigated whether neuromuscular block could be measured reliably from the orbital part of the OO muscle by the use of acceleromyography.Methods: During propofol, fentanyl, and alfentanil anaesthesia two TOF‐Guards® (Organon Teknika NV, Boxtel, the Netherlands) with acceleration transducers placed on the distal phalanx of the thumb and over the middle of the eyebrow, respectively, were used to measure neuromuscular block simultaneously in 23 patients during vecuronium‐induced and neostigmine‐antagonized neuromuscular block.For both muscles, the simultaneously recorded first response (T1) in the train‐of‐four (TOF) and TOF‐ratio were measured both during onset and recovery of the block. Furthermore, both the AP muscle T1 and TOF‐ratio responses were plotted against 10% intervals of the OO muscle responses during onset and recovery, respectively.Results: The orbicularis oculi muscle had a shorter latency and a faster recovery to TOF‐ratio 0.80 compared with the AP muscle. During onset and recovery, pronounced variations of the AP muscle T1 and TOF‐ratio responses were observed when compared with the OO muscle.Conclusion: A significant clinical disagreement exists between the degree of paralysis measured at the OO and the AP muscles. It is impossible to obtain a reasonable estimate of the degree of block at the AP muscle when the block is measured from the OO muscle with acceleromyography. If used, there is substantial risk of overlooking a residual block, and adequate recovery of the block should be confirmed by a final AP muscle measurement.
Reproducibility of in vitro contracture test results in patients tested for malignant hyperthermia susceptibility
Authors: Islander G. , Örding H. , Bendixen D. , Ranklev Twetman E. 
Published: March 2003

Background: The in vitro contracture test (IVCT) is the golden standard to diagnose malignant hyperthermia susceptibility (MHS). A high reproducibility is important for a high validity of a test.Methods: We have therefore analyzed IVCT in 838 patients, investigated in two laboratories. Each halothane and caffeine test was performed in two muscle strips. The test results were analyzed with respect to reproducibility of abnormal outcomes within pairs of tested muscle strips and size of contractures, thresholds and quality criteria. The patients were tested according to the European Malignant Hyperthermia Group protocol (EMHG). To fulfill quality criteria in the EMHG protocol the twitch height should be 10 mN (1 g) or more. For the caffeine test a minimum contracture of 50 mN (5 g) or more at 32 mmol l−1 caffeine could be used as an alternative quality criterionResults: There was better reproducibility with larger contractures. The correlation between size of contractures and fraction of muscle strips with abnormal contractures was 0.77 or larger. Contractures < 5 mN (0.5 g) were reproducible in less than half of the tests. There was no difference in reproducibility or size of contractures between tests fulfillling all quality criteria and those not fulfillling these criteria.Conclusions: IVCT responses close to cut off limits, i.e. <5 mN (0.5 g) in the EMHG protocol, are less reproducible and must scientifically be considered as less reliable. The clinical cut off limits must remain unchanged for reasons of clinical safety. The outcome of quality measurements does not influence the test results.
Tranexamic acid given intraoperatively reduces blood loss after total knee replacement: a randomized, controlled study
Authors: Veien M. , Sørensen J. V. , Madsen F. , Juelsgaard P. 
Published: March 2003

Background: Extensive blood loss in total knee replacement (TKR) surgery is well known and is associated with a high transfusion rate of allogenic blood. Tranexamic acid (TXA) has been shown to reduce blood loss by 50% in this patient group, but only in cases with a perioperative loss of 1400–1800 ml. This study was performed to see if TXA offers any advantages in knee replacement surgery with blood loss at 800 ml.Methods: Thirty consecutive patients scheduled for TKR in spinal anesthesia with the use of a tourniquet, were randomized to TXA or non‐TXA. Tranexamic acid 10 mg kg−1 was given at conclusion of surgery and again 3 h later. Blood loss was registered.Results: Total blood loss was at all times significantly lower in the TXA group compared to the non‐TXA group (409.7±174.9 ml vs. 761.7±313.1 ml; P<0.001). There were no differences in coagulation parameters. No patients in the TXA group had a blood transfusion vs. 13% in the non‐TXA group (NS). No complications were registered in the two groups.Conclusion: We conclude that TXA significantly reduces blood loss after total knee replacement surgery.
Modulation of the inflammatory response to cardiopulmonary bypass by dopexamine and epidural anesthesia
Authors: Bach F. , Grundmann U. , Bauer M. , Buchinger H. , Soltész S. , Graeter T. , Larsen R. , Silomon M. 
Published: March 2003

Background:Cardiopulmonary bypass (CPB) induces a systemic inflammatory reaction. Microcirculation‐dependent alteration of the gut mucosal barrier with subsequent translocation of endotoxins is a postulated mechanism for this inflammatory response. This study was designed to elucidate whether two different approaches to modulate splanchnic perfusion may influence systemic inflammation to CPB.Methods:We examined 40 patients scheduled for elective coronary bypass surgery in a prospective, randomized study. One group (DPX) received dopexamine (1 µg · kg−1 · min−1) continuously after induction of anesthesia until 18 h after CPB. The control group (CON) received equal volumes of NaCl 0.9% in a time‐matched fashion. In a third group (EPI) a continuous epidural infusion of bupivacaine 0.25% [(body height (cm) – 100) · 10−1=ml·h−1] was administered for the whole study period. Procalcitonin (PCT), tumor necrosis factor (TNF‐α), soluble TNF receptor, human soluble intercellular adhesion molecule‐1, C‐reactive protein (CRP) and leukocyte count were measured as parameters of inflammation.Results:All parameters significantly increased following CPB. Increases of PCT, TNF‐α and leukocyte count were significantly attenuated in the DPX and EPI groups at different time points. However, neither splanchnic blood flow nor oxygen delivery and consumption were different when compared with the CON‐group.Conclusion:These results do suggest that mechanisms other than an improved splanchnic blood flow by DPX and EPI treatment have to be considered for the anti‐inflammatory effects.
Cerebrospinal fluid concentrations of atracurium, laudanosine and vecuronium following clinical subarachnoid hemorrhage
Authors: Tassonyi E. , Fathi M. , Hughes G. J. , Chiodini F. , Bertrand D. , Muller D. , Fuchs‐Buder T. 
Published: March 2003

Background: Neuromuscular blocking agents may exert central nervous system effects when they reach the brain. This study assessed the concentrations and the time course of passage of vecuronium, atracurium, and its metabolite laudanosine in the cerebrospinal fluid (CSF) of patients undergoing intracranial aneurysm clipping.Methods: Twenty‐five patients with subarachnoid hemorrhage were randomly allocated to receive an intravenous infusion of vecuronium (n=13) or atracurium (n=12). Arterial blood and lumbar CSF were sampled before and 1, 2, 3, 4 and 8 h after the start of the relaxant infusion. The samples were analyzed by liquid chromatography‐electrospray ionization mass spectrometry (vecuronium) and high‐pressure liquid chromatography (atracurium and laudanosine).Results: The data of 20 patients (10 in both groups) were analyzed. In 11 CSF samples from five patients atracurium was detected in concentrations from 10 to 50 ng/ml. Laudanosine was retrieved in all CSF samples at 1, 2, 3, 4 and 8 h; the highest CSF concentration of laudanosine occurred at 3 h [38 (18–63) ng/ml: median (range)]. Vecuronium was not found in any CSF sample.Conclusion: Significant concentrations of atracurium and laudanosine but not of vecuronium were detected in the CSF of patients during and immediately after intracranial aneurysm surgery.
Two propofol formulations are equivalent in small children aged 1 month to 3 years
Authors: Pessenbacher K. , Gutmann A. , Eggenreich U. , Gschanes A. , Rehak P. , List W. F. 
Published: March 2003

Background: Propofol has been widely used in general anesthesia. Although it is also often used in pediatric anesthesia, there has been only limited scientific evidence on the use of propofol in children up to 3 years.Methods: A prospective, randomized, double‐blind, therapeutic equivalence study comparing two propofol 1% emulsions (Propofol 1% Fresenius vs. Diprivan 1%) was performed in 60 patients scheduled for routine surgery or for diagnostic laparoscopic procedures requiring anesthesia. To guarantee comparability of age distribution between the two groups, a stratified randomization with patients younger than 12 months of age in a low age group and with patients aged 12 months to 3 years in a high age group was used. The average propofol induction dose and the average propofol infusion dose were analyzed to prove equivalence. The side‐effects profile was analyzed to compare the safety profiles of the two propofol formulations in this study.Results: There were no differences in baseline characteristics between the two treatment groups of high and low age. Medications used for induction and maintenance of anesthesia, and side‐effects profiles were comparable, as were the average propofol dose for induction of anesthesia (range of the mean dose 4.0–4.2 mg/kg) and for maintenance of anesthesia (range of the mean dose in the first hour 8.74–9.42 mg·kg−1·h−1).Conclusions: The two 1% propofol formulations were equally effective in our patient population of infants and young children between 1 month and 3 years of age. No differences between the two propofol formulations were found with regard to the circulatory reaction, lipid metabolism, dosages, and recovery profile in the studied age groups.
Effect of rewarming speed during hypothermic cardiopulmonary bypass on cerebral pressure–flow relation
Authors: Diephuis J. C. , Balt J. , Van Dijk D. , Moons K. G. M. , Knape J. T. A. 
Published: March 2003

Background: Cerebral blood flow is less dependent on arterial blood pressure during hypothermic cardiopulmonary bypass (CPB) compared to warm CPB. Fast rewarming has a more pronounced effect on cognitive performance in the elderly and causes an increased arterio‐jugular oxygen content difference. We studied the effect of rewarming and rewarming speed on cerebral pressure–flow relation in adult patients undergoing elective coronary artery bypass surgery with mild hypothermic CPB.Methods: Fifty patients were randomly assigned to either a slow rewarming strategy (0.24 °C/min) or a fast rewarming strategy (0.5 °C/min). Cerebral pressure–flow relation was assessed by a transcranial Doppler derived index for cerebral pressure–flow relation (Pressure–flow Index, PFI). The effect of rewarming speed on cerebral pressure–flow relation was assessed by comparing the absolute PFI value after rewarming between the two treatment groups.Results The mean PFI decreased significantly from 0.73 (standard deviation: 0.28) before rewarming to 0.54 (0.35) after rewarming in the slow rewarming group and from 0.63 (0.29) to 0.48 (0.30) in the fast rewarming group. Absolute PFI after rewarming was not significantly different (mean PFI difference = 0.06; 95% CI = − 0.13; 0.26) between both rewarming strategies.Conclusion: Rewarming from mild hypothermic CPB might result in pressure‐dependent cerebral blood flow velocity but rewarming speed did not aggravate the effect of rewarming on pressure–flow dependency.
Changes in intrathoracic blood volume associated with pneumoperitoneum and positioning
Authors: Hofer C. K. , Zalunardo M. P. , Klaghofer R. , Spahr T. , Pasch T. , Zollinger A. 
Published: March 2003

Background: It is still controversial whether elevated cardiac filling pressures after the onset of pneumoperitoneum are the consequence of increased intrathoracic pressure or of increased venous return. The aim of this study was to assess the effects of pneumoperitoneum and body positioning on intrathoracic blood volume (ITBV).Methods: Thirty anesthetized patients were randomly assigned to have CO2‐pneumoperitoneum (13 mmHg) either in a supine, in a 15° head‐up tilt or in a 15° head‐down tilt position. Measurements of ITBV and hemodynamics by the double indicator method were recorded after induction of anesthesia and application of a fluid bolus (Lactated Ringer's solution 10 ml/kg), after positioning and after induction of pneumoperitoneum.Results: Intrathoracic blood volume index (ITBVI) increased significantly after induction of pneumoperitoneum in all body positions (supine: from 18.5 ± 3.3 –20.2  ± 5.2 ml/kg (+6%) head‐up from 16.7 ± 3.8 – 17.4 ± 3.7 ml/kg (+16%) and head‐down: from 19.8 ± 5.6 – 20.5 ± 5.9 ml/kg (+14%)). Heart rate did not change significantly in any of the groups. Cardiac index showed a statistically significant change in the head‐down position with pneumoperitoneum (−11%). A good correlation was found for stroke volume (SV) with ITBV (r = 0.79), but not with central venous pressure (r = 0.26). Systemic vascular resistance index increased significantly in all three groups (supine +6%, head‐up +16%, head‐down position +14%).Conclusion: The present study indicates that the onset of pneumoperitoneum, even with moderate intra‐abdominal pressures, is associated with an increased intrathoracic blood volume in ASA I/II patients.
Comparison of the opioid‐sparing efficacy of diclofenac and ketoprofen for 3 days after knee arthroplasty
Authors: Silvanto M. , Lappi M. , Rosenberg P. H. 
Published: March 2003

Background: Comparative postoperative non‐steroidal anti‐inflammatory drug (NSAID) studies in orthopedic patients have usually been restricted in time to the first postoperative day. The opioid‐sparing effect of NSAIDs may be beneficial postoperatively as long as pain otherwise restricts ambulation and rehabilitation. We therefore compared the analgesic efficacy of the maximum recommended doses of diclofenac and ketoprofen for 3 days after knee arthroplasty.Methods: We studied 64 knee arthroplasty patients, operated on under spinal anesthesia. In a randomized, double‐blind and placebo‐controlled fashion, the patients received either i.v. diclofenac 75 mg (n = 24), ketoprofen 100 mg (n = 24) or saline (n = 16) in the recovery room, followed by oral diclofenac 150 mg/day, ketoprofen 300 mg/day or placebo, respectively, for 3 days, supplemented by patient‐controlled analgesia (PCA) with i.v. oxycodone.Results: The mean consumption of oxycodone during the first, second and third study days was 45.3, 22.3 and 15.2 mg in the diclofenac group, 43.5, 37.5 and 21.8 mg in the ketoprofen group, and 61.2, 45.9 and 36.1 mg, respectively, in the placebo group. Oxycodone consumption was significantly lower (P < 0.05) in the ketoprofen group than in the placebo group in the postoperative period 13–24 h and 61–72 h. Diclofenac was superior to placebo in the postoperative period 25–48 h (P < 0.01), 49–60 h (P < 0.05) and to ketoprofen at 49–60 h (P < 0.05). During administration of diclofenac on days 1–3 and ketoprofen on day 2, the mean pain scores (VAS) were lower than in the placebo group (P < 0.05). Six patients had difficulties in operating the PCA device. There were no differences in blood loss.Conclusion: We conclude that in the first day after knee arthroplasty (13–24 h), ketoprofen exerted an opioid‐sparing effect. After day 1 (25–60 h), with the doses used, diclofenac proved to be better than placebo, whereas ketoprofen was not.
Fatal amniotic fluid embolism diagnosed histologically
Authors: Aguilera L. G. , Fernandez C. , Plaza A. , Gracia J. , Gomar C. 
Published: March 2003

Although the mortality of amniotic fluid embolism remains very high, there are more and more reports of patients surviving after prompt and aggressive therapy. However its pathogenesis is controversial, and, in some cases, an anaphylactic reaction to the amniotic fluid rather than the hemodynamic changes following mechanical obstruction by an embolus has been proposed as the underlying pathophysiological mechanism.In this paper we describe a case of amniotic fluid embolism with florid clinical features and a difficult and delayed diagnosis. On autopsy, clear‐cut histological changes of amniotic fluid embolism were found.