Quality assessment of unfractionated heparin using 1H nuclear magnetic resonance spectroscopy.

Due to problems, especially anaphylactoid reactions, raised by impure unfractionated heparin the quality assessment of heparin has to be reconsidered. Neither the USP nor the European Pharmacopoeia are able to guarantee the purity of heparin, i.e., the limitation of oversulfated chondroitin sulfate (OSCS) which was found to be the reason for the allergic adverse effects. In the first run the regulatory authorities ask for 1H NMR spectroscopic and capillary electrophoretic measurements in order to characterize the impurity profile of heparin. Using an optimized 1H NMR method the limit of detection for OSCS was found to be 0.1%. In addition, it is possible to reliably quantify both OSCS and dermatan sulfate (DS), the latter being an indicator of poor purification of the unfractionated heparin. Screening of more than 100 heparin samples collected from international markets revealed a high number of samples containing substantial amounts of DS and a number of samples containing OSCS in an amount higher than 0.1%.

Degradation of heterocyclic aromatic amines in oil under storage and frying conditions and reduction of their mutagenic potential.

Heterocyclic aromatic amines (HAA) were systematically studied concerning their partition behavior in water/oil-systems and their thermostability in different animal derived fats and vegetable oils. Partitioning of IQx-compounds and PhIP in water/oil systems was found to depend on the polarity defined by the molecular structure and on the pH-value of the aqueous phase. In particular, beta-carbolines norharman and harman showed a significant strong lipophilic character at alkaline pH. After heating in frying fats at 130 degrees C, contents of IQx compounds and PhIP were reduced by more than 40% and after heating at 180 degrees C less than 10% of the HAA initial concentration was recovered. By contrast, norharman and harman were much more stable under equivalent conditions. The present study leads for the first time to the conclusion that degradation of HAA in frying fats strongly correlates to the type of frying fat and is promoted by lipid oxidation products. Firstly, addition of hydroperoxides to model oils lead to a decrease of HAA during storage at 40 degrees C. Secondly, stability of HAA correlated with the content of unsaturated fatty acids in the oil, which is indicative for the oxidative stability of the medium. Degradation of HAA by heat treatment was associated with a reduction of their mutagenic potential towards strain TA98 of Salmonella typhimurium.

[Not Available]. / Qualitätssichernde Maßnahmen hinsichtlich Mykotoxinen in der Getreidemühle.

In the present study the quality management system of 39 milling companies was investigated regarding the analysis and the prevention of mycotoxin contamination. 21 companies- mainly companies with a high processing volume - established a quality management system according to DIN EN ISO 9000ff. In view of previous studies the data indicated an improvement of quality management systems in the milling industry during the last years. Nevertheless some powerful instruments of preventive quality management like a supplier assessment have still not been efficiently used in many companies. The monitoring of mycotoxins or the participation in existing monitoring programmes is mainly limited to companies with a high production volume. It is recommended that monitoring programmes should become more attractive for small- and medium-sized companies. Further the development of quality management systems for small and medium-sized companies is required.

Initial clinical experience with remifentanil, a new opioid metabolized by esterases.

Remifentanil is a new, esterase-metabolized opioid for anesthesia. Nonspecific esterases terminate the drug effect, with a context-sensitive half-time which plateaus at 3-4 min. This dose-ranging pilot study was designed to estimate the dose requirement of remifentanil for abolition of the responses to skin incision and intraoperative stimuli, and to determine the speed of recovery. Fifty-one unpremedicated patients took part at two centers. Anesthesia was induced with propofol, 67% nitrous oxide, and vecuronium. Remifentanil was then given (1 microgram/kg, plus an infusion of 0.0125-1.0 micrograms.kg-1.min-1). Responses were defined as: > 15% increase in systolic blood pressure or > 20% increase in heart rate, tearing, sweating, movement, or coughing. Responses to incision or surgery were treated with 0.5 micrograms/kg remifentanil boluses and a 50% increase in infusion rate, which could be done twice. Subsequent responses were treated with propofol or isoflurane. Remifentanil and nitrous oxide administration were terminated after the incision was closed. ED50 for response to skin incision varied between the two study sites (0.020 and 0.087 microgram.kg-1.min-1). ED50 for response to all surgical stimuli was 0.52 microgram.kg-1.min-1. At 0.3 microgram.kg-1.min-1 or more, only 3 of 21 patients required isoflurane. Recovery was not longer in patients receiving larger doses to spontaneous ventilation (2.5-4.6 min), tracheal extubation (4.2-7.0 min), and response to verbal command (3.0-4.6 min). Postoperative pain was reported in most patients (92%) at a median time of 21 min. We conclude that remifentanil was effective and well tolerated as a component of nitrous oxide-opioid-relaxant anesthesia.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of the fiberscope in the critically ill patient.

The role of the fiberscope in the management of difficult and failed intubations has been well established and the importance of learning this valuable skill has been emphasized. Nonetheless, the fiberscope is underutilized in anesthesia and critical care practices because of a high rate of intubation failure. The main cause of failure is lack of expertise in maneuvering the fiberscope. Other technical causes of failure include fogging or clouding of the fiberscope's lens, drifting off the midline, and inability to advance the endotracheal tube or withdraw the fiberscope after completing intubation. Proper selection of the size of the fiberscope in relation to the size of the endotracheal tube, adequate lubrication, and careful passage of the fiberscope through the distal opening of the tracheal tube (not the Murphy eye) prevent difficulties encountered during advancement of the tube or upon withdrawal of the bronchoscope. Patient-related causes include inadequate topical anesthesia, which leads to abrupt movement of the larynx, laryngeal spasm, coughing, and copious secretions; a large floppy epiglottis; and tumor and edema of the upper airway, which also interfere with exposure of the larynx. Various approaches for learning and applying fiberoptic endoscopy have been instituted. The key to increased success involves initial training and practice with an intubation model and tracheobronchial tree. These models enable the learner to develop the eye-hand coordination skills needed to use the fiberscope properly. The fiberscope is best used in patients after learning to perform three simultaneous movements--advancing the fiberscope, coordinated rotation of the insertion cord, and bending the tip of the fiberscope while traversing the airway. After the technical skills of the fiberscope become second nature, the endoscopist can give more attention to patient-related factors to improve the success rate of tracheal intubation. Expert use of the fiberscope can be a life-saving measure through alleviating major airway complications and unnecessary tracheostomies.

Desflurane versus propofol anesthesia: a comparative analysis in outpatients.

This study compares the induction, hemodynamic, and recovery characteristics of a general anesthetic with desflurane to one with propofol. Sixty outpatients presenting for orthopedic surgery received either a propofol induction of anesthesia followed by desflurane and nitrous oxide (Group 1), a propofol induction followed by propofol infusion and nitrous oxide (Group 2), a desflurane and nitrous oxide induction and maintenance (Group 3), or a desflurane induction and maintenance (Group 4). The quality of induction was inferior in Groups 3 and 4 with more breath-holding and excitation than in Groups 1 and 2. However, there was a more rapid emergence in Group 4 patients than any of the other groups. Group 4 patients were able to say their names (5.6 +/- 2.0 min vs 10.3 +/- 3.3 min, 8.6 +/- 3.1 min, and 9.3 +/- 1.5 min for Groups 1, 2, and 3, respectively) sooner after the discontinuation of anesthesia. Nonetheless, intermediate recovery was similar in Groups 2 and 4 being numerically but not statistically more rapid than in Groups 1 and 3. This pattern of intermediate recovery was also demonstrated by psychomotor function test results. Although there was no difference between the groups in postoperative narcotic requirement, more patients in Group 3 vomited (50%) than in either Group 2 (0%) or Group 4 (12.5%). Hemodynamically, the anesthetics were very similar. Although desflurane was a difficult drug to use for induction of anesthesia, this study demonstrates that desflurane is a suitable maintenance anesthetic for ambulatory surgery because it provides a rapid awakening and an intermediate recovery similar to propofol.

Upper respiratory tract infections and general anaesthesia in children. Peri-operative complications and oxygen saturation.

Conflicting reports regarding the hazards of anaesthesia in children presenting for surgery with an upper respiratory tract infection have appeared in the literature. In the present study 130 children undergoing general anaesthesia with face mask for myringotomy and grommet insertion were graded as having either an acute or recent upper respiratory tract infection or were asymptomatic according to predetermined clinical symptoms and signs. The severity of respiratory and related complications were scored during induction, emergence and recovery. The peripheral oxygen saturation was recorded during induction, emergence, transfer to the recovery ward and in the recovery ward itself. There were no significant differences (p greater than 0.05) in the complication scores between the three groups of children. However, the incidence of hypoxaemia (oxygen saturation less than or equal to 93%) was significantly greater during transfer in the acute infection group (p = 0.001) and the recent infection group (p = 0.02), as well as during recovery in the acute group (p = 0.03) compared with asymptomatic children.

Propofol versus thiamylal-enflurane anesthesia for outpatient laparoscopy.

STUDY OBJECTIVE: To determine whether propofol anesthesia differs from thiamylal-enflurane anesthesia in induction characteristics, intraoperative hemodynamics, postoperative side effects, and postoperative psychomotor function recovery. DESIGN: A randomized, double-blind, two-group study. SETTING: A large university hospital with gynecologic outpatient operations performed in an integrated operating room suite. PATIENTS: Sixty adult women (ASA physical status I or II) undergoing an outpatient gynecologic laparoscopic operation with an anesthesia time of approximately 60 minutes. INTERVENTIONS: No pharmacologic premedication. Pretreatment with intravenous droperidol 0.6 mg and sufentanil 0.2 micrograms/kg before induction of anesthesia. Anesthesia was induced with either thiamylal 4 mg/kg (Group 1) or propofol 2.5 mg/kg (Group 2). Anesthesia was maintained with either nitrous oxide (N2O) and enflurane, 2-0.5% inspired concentrations; (Group 1) or with a continuous infusion of propofol 200-100 micrograms/kg/min and N2O (Group 2). MEASUREMENTS AND MAIN RESULTS: In psychomotor function tests (Trieger dot test and p-deletion test) administered preoperatively and postoperatively, no difference was found between the groups. No difference was found in induction time, although significantly more patients reported pain after the propofol injection, or in intraoperative hemodynamics (mean arterial pressure and heart rate). Immediate recovery time (emergence from anesthesia) and intermediate recovery time (ambulation, oral intake, and discharge time) were significantly shorter after propofol anesthesia. Fewer postoperative side effects, such as nausea and vomiting, were reported after propofol anesthesia. CONCLUSIONS: Induction and maintenance of anesthesia with propofol were comparable to those with thiamylal-enflurane, except patients experienced more pain on injection after propofol. Both immediate and intermediate recovery were more rapid after propofol anesthesia compared with enflurane-based anesthesia.