bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of learning during an anaesthesiological multicentre trial
Authors: Honkavaara P. , Paloheimo M. 
Published: January 2009

Background: After the completion of a multicentre study, it was disputed whether becoming acquainted with a novel drug would affect dosing, and how many consecutive patients would be sufficient for this phenomenon.Methods: A post hoc analysis of the data on 408 patients from a multicentre study on propofol was performed to reveal a possible learning effect. For study purposes, the patients were given consecutive anaesthetic serial numbers per anaesthesiologist. Patients eligible for the study with serial numbers 3–8 (113) were included in the initial group, and numbers 12–17 (89) in the end group.Results: The patients in the end group opened their eyes (4.1 vs. 5.5 min, P<0.05), gave their date of birth (4.5 vs. 6.3 min, P<0.005) and walked sooner (27.1 vs. 49.8 min, P<0.05) than the patients in the initial group. They received a higher dose of propofol at induction (2.37 vs. 2.26 mg kg‐1, P<0.05) and the last additional dose of propofol earlier (3.3 vs. 2.7 min, P<0.05).Conclusion: This study shows that the learning effect can influence the results in a multicentre study. Learning contamination may occur if a novel drug is dosed by clinical judgement, and if the allocation of patients into groups is markedly uneven during the different stages of the study.
Subarachnoid and intravenous PCA versus bolus administration for postoperative pain relief in orthopaedic patients
Authors: Rundshagen I. , Kochs E. , Standl Th. , Schnabel K. , Esch J. Schulte am 
Published: January 2009

Background: Patient‐controlled analgesia (PCA) with intravenous piritramide and subarachnoid bupivacaine was studied during postoperative pain management in comparison with nurse‐administered bolus injections.Methods: Following general anaesthesia (n=60) patients randomly received either 3.75–7.5 mg i. v. piritramide on demand (group P‐Bolus) or via PCA (group P‐PCA; initial bolus: 3.75 mg i. v. piritramide, baseline rate: 1 mg/h, demand‐dose 1.5 mg, lockout time: 20 min). Following continuous spinal anaesthesia (n=60; CSA; 28‐G spinal catheter) patients randomly received a subarachnoid injection of 1.5 ml bupivacaine 0.25% every 2–4 h (group B‐Bolus) or a baseline infusion of 0.5 ml/h bupivacaine 0.125% plus 0.5 ml bupivacaine 0.125% on demand via PCA (group B‐PCA; lockout time: 30 min). Pain ratings were assessed hourly by patients using a visual analogue scale (0=no pain, 100 mm=unbearable pain). Statistics: multivariate analysis of variance.Results: While pain scores did not differ between group P‐Bolus and P‐PCA, group B‐PCA showed the lowest pain ratings (18±22 mm) differing significantly from group B‐Bolus (41±32 mm: P<0.001). Group P‐PCA required more piritramide than group P‐Bolus (46±15 mg vs. 31±13 mg, P = 0.001). In contrast group B‐PCA required less bupivacaine than group B‐Bolus (18±4 vs. 23±7 mg, P=0.002).Conclusion: PCA with CSA was more effective than nurse‐administered bolus‐administration of bupivacaine, while the present study failed to show superiority of i. v. PCA over i. v. bolus‐administration of piritramide. PCA using the subarachnoid route is a promising concept for treatment of postoperative pain in orthopaedic patients, while the PCA piritramide regime of this study warrants improvement.
The accuracy and precision of four infrared aural canal thermometers during cardiac surgery
Authors: Imamura M. , Matsukawa T. , Ozaki M. , Sessler D. I. , Nishiyama T. , Kumazawa T. 
Published: January 2009

Background: Four infrared aural canal thermometers are currently available in Japan: Geniusr̀, Thermoscanr̀, Quickthermor̀, and Thermopitr̀. We therefore tested the hypothesis that each is sufficiently accurate and precise for clinical use.Methods: For the purpose of this investigation, we considered accuracy to be the mean difference between the test thermometers and the reference thermocouple. Precision was considered to be the standard deviation of the difference between the test and reference values. We evaluated ten patients undergoing cardiopulmonary bypass with moderate hypothermia (≅30°C). Aural canal temperatures were measured in random order with each infrared thermometer, and compared with readings from a thermocouple positioned at the contralateral tympanic membrane.Results: Compared to the thermocouple, the Geniusr̀ and Thermoscanr̀ both had regression slopes >0.85 and correlation coefficients near 0.87; in contrast, slopes of the Quickthermor̀ and Thermopitr̀ regressions were 0.68 and 0.53, respectively. The correlation coefficients for each were <0.65. The accuracy (offset, or bias) was near 0°C with both the Geniusr̀ and Thermoscanr̀ thermometers. In contrast, it was 1.1°C with the Quickthermor̀ and a full 2.3°C with the Thermopitr̀. The precision (standard deviation) of the measurements, however, was ≅0.8°C in each case.Conclusion: We conclude that none of the tested aural canal infrared thermometers was sufficiently accurate and precise for perioperative use.
Catheter‐induced thrombus in the superior vena cava diagnosed by transesophageal echocardiography
Authors: Weber T. , Huemer G. , Tschernich H. , Kranz A. , Imhof M. , Sladen R. N. 
Published: January 2009

Background: To present the role of transesophageal echocardiography (TEE) in the diagnosis and management of catheter‐related superior vena cava thrombosis.Case history: A 42‐year‐old woman with severe Crohn's disease presented with septic shock and pulmonary embolism three weeks after emergency laparotomy and ileocolic resection for small‐bowel perforation with peritonitis. Cardiopulmonary evaluation with ECG, pulmonary artery catheter and TEE demonstrated no evidence of acute myocardial ischemia or ventricular dysfunction; hemodynamic indices were consistent with severe sepsis. TEE revealed a large sheathing thrombus surrounding a central venous catheter used for parenteral nutrition. A spiral CT scan of the chest confirmed multiple peripheral pulmonary emboli. Treatment consisted of systemic anticoagulation and antibiotics. To avoid further pulmonary embolism, the central venous catheter was not removed until six days later under TEE monitoring, which revealed that the thrombus was firmly adherent to the superior vena cava. The patient made an uneventful recovery and was discharged from hospital on long‐term anticoagulant therapy.Conclusion: In a case of catheter‐induced superior vena cava thrombosis with septicemia and pulmonary embolism, bedside TEE was very helpful to make the correct diagnosis early, assess thrombus size during anticoagulation, and monitor cardiac performance and thrombus disposition during central venous catheter removal.
Preoperative oral granisetron prevents postoperative nausea and vomiting
Authors: Fujii Y. , Tanaka H. , Toyooka H. 
Published: January 2009

Background: Postoperative nausea and vomiting (PONV) is a commonly observed adverse effect of anaesthesia. This study was designed to evaluate the efficacy of granisetron administered orally for preventing PONV in female patients undergoing major gynaecological surgery.Methods: In a prospective, randomized, placebo‐controlled, double‐blind study, 120 patients received orally either placebo or granisetron (1 mg, 2 mg or 4 mg) (n=30 for each) 1 h before surgery. The same standard general plus regional anaesthetic technique was employed throughout. Postoperatively, during the first 24 h after anaesthesia, the incidence of PONV and adverse events was recorded by nursing staff.Results: The incidence of PONV was 47% with placebo, 37% with granisetron 1 mg, 10% with granisetron 2 mg and 10% with granisetron 4 mg (P<0.05; overall Fisher's exact probability test). No difference in the incidence of adverse events was observed among the groups.Conclusion: Preoperative oral granisetron in a minimum dose of 2 mg is effective for preventing PONV after major gynaecological surgery.
Dose‐related cardiovascular effects of amrinone and epinephrine in reversing bupivacaine‐induced cardiovascular depression
Authors: Igarashi T. , Hirabayashi Y. , Saitoh K. , Fukuda H. , Shimizu R. , Mitsuhata H. 
Published: January 2009

Background:To ascertain the efficacy of amrinone and epinephrine in reversing bupivacaine‐induced cardiovascular depression, we investigated the time course of recovery of cardiac function with 3 doses of both agents after bupivacaine administration.Methods:In sevoflurane‐anaesthetized dogs, bupivacaine was infused intravenously at 1 mg . kg−1. min−1until mean arterial pressure fell to 60 mmHg or less. The 3 doses of amrinone (1, 2, and 4 mg . kg−1) or the 3 doses of epinephrine (2, 5, and 10 μg . kg−1) were administered as a bolus in randomized order in each dog.Results:Amrinone improved maximum left ventriculardP/dt, a time constant of left ventricular isovolemic relaxation and cardiac index persistently and dose‐relatedly. Amrinone increased heart rate and decreased left ventricular end‐diastolic pressure and systemic vascular resistance index. Amrinone at 1 and 2 mg . kg−1significantly increased mean arterial pressure, but amrinone at 4 mg . kg−1did not. Epinephrine increased mean arterial pressure, maximum left ventriculardP/dt, and systemic vascular resistance dose‐relatedly. The duration of action of epinephrine, peaking at 1 min and subsequently decreasing by 10 min after administration, did not differ among the groups. Epinephrine at all doses failed to improve a time constant of left ventricular isovolemic relaxation and cardiac index. ECG evidence of serious ventricular dysrhythmias was seen in 1 out of 6 dogs after administrating each dose of amrinone and in 3, 3 and 5 out of 6 dogs after administrating 2, 5 and 10 μg . kg−1of epinephrine, respectively.Conclusion:Bolus amrinone may have a certain efficacy in reversing bupivacaine‐induced cardiovascular depression, and improving cardiac contractility and relaxation dose‐relatedly. In contrast to amrinone, bolus epinephrine remains indispensable for resuscitation, causing a rapid, massive, transient and doserelated rise in blood pressure. However, the use of amrinone may be limited predominantly by a decrease in systemic vascular resistance, while the use of epinephrine may be limited predominantly by the generation of serious ventricular dysrhythmias and lack of effectiveness on cardiac index and on cardiac relaxation.
Elevated methemoglobin in patients with sepsis
Authors: Ohashi K. , Yukioka H. , Hayashi M. , Asada A. 
Published: January 2009

Background:It has been reported that large amounts of nitric oxide (NO) are released in patients with sepsis. NO is converted to methemoglobin and nitrate. This study was designed to determine whether blood methemoglobin levels were increased in patients with sepsis or septic shock.Methods:Forty‐five critically ill patients including 8 with sepsis but without shock, 6 with septic shock and 31 non‐septic patients were enrolled in the study. For septic and septic shock patients, blood methemoglobin concentrations were measured during sepsis or septic shock and at the time of recovery or just before the onset of sepsis. For the remaining non‐septic patients, methemoglobin concentrations were measured atICUadmission and discharge.Results:Blood methemoglobin levels in the presence of sepsis or septic shock were significantly (P<0.05) higher than those in non‐septic patients and those at recovery or just before the onset of sepsis in both septic and septic shock patients.Conclusions:Blood methemoglobin concentration may be useful as a marker of the onset of sepsis or septic shock.
Correction of pressure waveforms recorded by fluid‐filled catheter recording systems: A new method using a transfer equation
Authors: Lambermont B. , Gerard P. , Detry O. , Kolh P. , Potty P. , D̂Orio V. , Marcelle R. 
Published: January 2009

Background: Pressure measuring systems using fluid‐filled catheters can result in the recording of distorted pressure waveforms. It results in phase delay, overestimation of systolic and, to a lesser extent, of diastolic pressure. We designed and evaluated a method to correct this pressure waveform distortion using an appropriate transfer equation obtained from the dynamic response of the fluid‐filled catheter. This transfer equation is based on the principle that a fluid‐filled catheter recording system is considered as an underdamped dynamic system fully characterized by its natural frequency (ωn and damping ratio (ζ).Methods: Pressure waveforms, simultaneously recorded in vitro or in vivo by a fluid‐filled catheter (Pc) and a micromanometertipped catheter (Pref), were used to validate the method. Dynamic response of the catheter used was obtained from a fastflush test. The corrected signal (Ppred) was obtained using con, Ωnζ and the following transfer equation:d2Pc/dt2+ 2 ωnζ dPc/dt+ωn2Pc=C Ppred (t)After correction of Pc, Ppred was compared, using a linear regression, with Pref taken as reference.Results: Our results showed that Ppred was fitted to Pref with excellent coefficient correlation (0.99). The mean error and the standard error of estimate were respectively –1.16 mmHg and 1.4 mmHg.Conclusion: This new method can convert the distorted pressure waveforms transmitted by any fluid‐filled catheters into high‐fidelity signals. It suppresses the phase delay and the over‐estimation of systolic pressure induced by fluid‐filled catheters.
Postoperative analgesia with epidural bupivacaine and low‐dose fentanyl ‐ a comparison of two concentrations
Authors: Sjöström S. , Bläss J. 
Published: January 2009

Background: The purpose of the study was to compare the analgesic and side effects of two epidurally administered mixtures of bupivacaine and fentanyl with the same drug ratios.Methods: One hundred patients scheduled for colorectal surgery were randomized to receive a thoracic epidural infusion of either bupivacaine 0.12% with fentanyl 2 μg/ml or bupivacaine 0.24% with fentanyl 4 μg/ml during 48 h postoperatively. The pumps were adjusted to keep the visual analogue scale (VAS) pain score at 3 or less (on a scale of 0–10) with a minimum of adverse effects.Results: There were no statistically significantly differences between the two groups in VAS pain scores. The average VAS pain score resting varied between 0.5 and 1, and coughing between 1.9 and 3.4. One case of respiratory depression with breathing frequency 7 occurred in each group, but none of the patients required naloxone. One patient in the low concentration group developed partial motor weakness in both legs 36 h postoperatively. Equal drug amounts ‐ bupivacaine 10.8–11 mg/h and fentanyl 18‐18.4 μg/h ‐ were given in both groups throughout the study.Conclusions: Both groups had low pain scores with few and comparable adverse effects. It thus seems that the volume is not important when mixtures of bupivacaine and fentanyl in the studied concentrations are infused epidurally at a low thoracic level. Practical reasons favour the higher concentration mixture.
Porcine‐derived surfactant treatment of severe bronchiolitis
Authors: Luchetti M. , Casiraghi G. , Valsecchi R. , Galassini E. , Marraro G. 
Published: January 2009

Background: It is hypothesized that surfactant treatment helps to improve severe bronchiolitis by restoring surfactant system activity. This study aims to assess the effect of surfactant on gas exchange, peak inspiratory pressure and duration of mechanical ventilation and intensive care unit (ICU) stay in children with severe bronchiolitis.Methods: Twenty children with bronchiolitis requiring mechanical ventilation were randomly assigned to one of two groups (10 patients each). Group A was treated with continuous positive pressure ventilation (CPPV) plus surfactant. Group B was treated with CPPV only. Porcine‐derived surfactant, 50 mg/kg body weight, was instilled into the trachea. Arterial tension of oxygen/fraction of inspired oxygen (PaO2/FiO2) ratio, arterial tension of carbon dioxide (PaCO2), and peak inspiratory pressure (PIP) were assessed. Heart rate and non‐invasive arterial blood pressure were monitored. The duration of CPPV and the length of ICU stay were also recorded. Finally, the incidence of complications and the survival rate were assessed.Results: In group A, the PaO2/FiO2 ratio significantly improved from 1 h and a reduction in PaCO2 was noted from 12 h. A reduction of PIP was observed from 3 h. The duration of CPPV and the length of ICU stay were reduced in group A. No complications were reported in either group and all children survived.Conclusions: Surfactant treatment of severe bronchiolitis appeared to improve gas exchange, reduce PIP and shorten CPPV and ICU stay. However, these initial results must be confirmed by a larger and more rigorously controlled study.
Preservation of humidity and heat of respiratory gases in spontaneously breathing, tracheostomized patients
Authors: Thomachot L. , Viviand X. , Arnaud S. , Vialet R. , Albanese J. , Martin C. 
Published: January 2009

Background: Ventilation with endotracheal intubation bypasses the upper airway and the normal heat and moisture exchanging process of inspired gases. A continuous loss of moisture and heat occurs and predisposes patients to serious airway damage. We therefore prospectively studied one heated humidifier system, one cold humidifier system and one heat and moisture exchanger in spontaneously breathing, tracheostomized intensive care unit patients to determine the ability to preserve patients' heat and water.Methods: Following a randomized order, 10 patients were spontaneously ventilated for 24‐h periods with the Nam 35r̀ humidifier (Europe Medical, France, a cold water humidifier), the heat and moisture exchanger Trach‐Ventr̀ (Gibeck, Sweden), and the Aerodyner̀ humidifer (Kendall, USA). In each patient, during the inspiration phase, the following measurements were performed: mean values of temperature and relative humidity of inspired gases. The absolute humidity was calculated. Values were obtained in each patients after 40 min and 24 h.Results: The Trach‐Ventr̀ filter and the Aerodyner̀ humidifier had better humidification and thermic capacities than the Nam 35r̀ humidifier (P<0.001). With the Nam 35r̀ humidifier, no patient had temperature of inspired gas >29°C. Concerning absolute humidity of inspired gases, the Nam 35r̀ humidifier achieved a lower performance than the other two tested systems (P<0.001).Conclusion: In spontaneously breathing, tracheostomized intensive care unit patients, the Trach‐Ventr̀ heat and moisture exchanger and the Aerodyner̀ heated system achieved satisfactorily preservation of heat and humidity of inspired gases.
Inhibited hypothalamic histamine metabolism during isoflurane and sevoflurane anesthesia in rats
Authors: Hashimoto Y. , Hashimoto Y. , Hirota K. , Matsuki A. 
Published: January 2009

Background: Histamine is most densely distributed in the hypothalamus and has an important effect on consciousness or wakefulness. It has been little considered whether general anesthetics could exert their effects on hypothalamic histamine metabolism. The present study was conducted to investigate the effects of isoflurane and sevoflurane anesthesia on hypothalamic histamine metabolism.Methods: Sixty male Wistar rats were divided equally into isoflurane and sevoflurane anesthesia groups. Each group was divided into three equal sub‐groups: the control, anesthesia and recovery groups. The rats of the anesthesia and recovery groups were exposed to either 2% isoflurane or 3% sevoflurane for 30 min. The recovery group was kept in air for 30 min after anesthesia. The rats were decapitated to dissect out hypothalamus which was divided into the fore and rear portion. The contents of histamine and 1‐methylhistamine, which is a main histamine metabolite, were determined by high‐performance liquid chromatography. The obtained data were analyzed by one‐way analysis of variance followed by Bonferoni's test.Results: Histamine contents of the anterior and posterior hypothalamus in both isoflurane and sevoflurane groups increased significantly during the anesthesia and 1‐methylhistamine contents of the anterior and posterior hypothalamus in sevoflurane group increased remarkably after anesthesia. The increases of histamine contents supposedly reflected inhibited histamine metabolism and the increases of 1‐methylhistamine would be caused by acceleration of histamine degradation.Conclusions: Histamine metabolism was inhibited during both isoflurane and sevoflurane anesthesia and accelerated only in the posterior hypothalamus during the emergence from these anesthetics.
Waste gas exposure during desflurane and isoflurane anaesthesia
Authors: Hobhahn J. , Hoerauf K. , Wiesner G. , Schrögendorfer K. , Taeger K. 
Published: January 2009

Background: Currently, there are no data available concerning the occupational exposure to desflurane during general anaesthesia. This prospective, randomized study reports on occupational exposure to desflurane, compared to isoflurane, in a modern operation theatre (OT).Methods: The study was performed in an OT equipped with a modern air‐conditioning system and with a low‐leakage anaesthesia machine connected to a central scavenging system. Trace concentrations of the anaesthetics were measured continuously by means of a photoacoustic infrared spectrometer during general anaesthesia in 30 patients undergoing eye surgery. Values were obtained within the breathing zone of the anaesthetist, the surgeon, the auxiliary nurse and at the mouth of the patient.Results: Desflurane and isoflurane were administered with median (range) endtidal concentrations of 4.7 (3.8–10.3) vol% and 0.9 (0.6–1.4) vol%, respectively. The personnel‐related median values of the average trace concentrations of desflurane and isoflurane were 0.5 (0.01–7.5) ppm and 0.2 (0.01–1.6) ppm, respectively.Conclusions: Occupational exposure to desflurane is low in the environment of a modern OT, even though it has to be administered in approximately 5‐fold higher concentrations compared to isoflurane.
Intravenous endotoxin does not increase tissue extravasation of albumin in rats
Authors: Metcalf K. , Sundqvist T. , Lisander B. 
Published: January 2009

Background: It is unclear whether activation of the inducible nitric oxide synthase (iNOS) increases or decreases the extravasation of plasma.Methods: Chloralose anaesthetised male Wistar rats receivedE. colilipopolysacharide (LPS), 3 mg kg‐1i.v., or the corresponding volume of saline, 3 or 5 h before the end of the experiment. Mean arterial pressure (MAP) and heart rate (HR) were recorded. Tissue clearance of radio‐labelled albumin, during the last 2 h of each experiment, was determined by a double‐isotope method. In separate animals, the serum concentration of nitrite and nitrate was determined, 5 h after LPS or the solvent.Main Results: LPS initially decreased MAP and lastingly increased HR. In the 3‐h LPS animals (n=8), tissue plasma clearance was lower in the heart and calf muscle and increased only in diaphragm, compared to corresponding control animals (n=8). In the 5‐h LPS rats, clearance was lowered (n=8) in the entire gastrointestinal tract and in testes, compared to controls (n=8). The serum nitrite/nitrate concentration was higher in animals given LPS (n=6) than in controls (n=6).Conclusion: After LPS, tissue clearance of albumin was not increased in any major tissue, in spite of increased serum levels of NO end products. Apparently, after activation of iNOS, the augmented release of NO is not necessarily associated with increased albumin extravasation.