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The precise quantification of the pyroelectric coefficient p is indispensable for the characterization of pyroelectric materials and the development of pyroelectric-based devices, such as radiation sensors or energy harvesters. A summary of the variety of techniques to measure p is given in the present review. It provides a classification after the thermal excitation and an outline of capabilities and drawbacks of the individual techniques. The main selection criteria are: the possibility to separate different contributions to the pyroelectric coefficient, to exclude thermally stimulated currents, the capability to measure p locally, and the requirement for metallic electrodes. This overview should enable the reader to choose the technique best suited for specific samples. [ABSTRACT FROM AUTHOR]

Background: The evaluation of German postanesthesia questionnaires is often restricted to inpatient medical care. The anesthesiological questionnaire for patients (ANP) has previously been validated only after medical care of inpatients. Therefore, the aim of the present study was to evaluate the validity of the ANP in the context of outpatient surgery and anesthesia., Methods: Data from 4547 patients (mean age 18-89 years, sex: m/f, 55%/45%), scheduled for ambulatory orthopedic and trauma surgery, were analyzed. All patients received a standard induction of anesthesia with propofol, sufentanil and 4 mg dexamethasone. Maintenance of anesthesia was achieved with a balanced technique comprising volatile anesthesia (either sevoflurane or desflurane) and sufentanil. In addition, patients undergoing operations on the anterior cruciate ligament received a femoral nerve block with 12-15 ml 0.5% ropivacaine. Of the patients 13% remained in hospital overnight as a result of complex operations (combined anterior and posterior cruciate ligament repair, hip arthroscopy and 10% of those undergoing shoulder operations). Before discharge from the recovery room, patients were asked to answer questions with respect to postoperative symptoms 1h after anesthesia (ESNA 19 items), at the time of interview (ABZ 17 items) and about overall patient satisfaction (10 items). These results were matched with the type of procedure and time data from the patient administration system. All data were analyzed descriptively using parametrical tests., Results: At both time points, pain in the area of the operation was the predominant symptom (ESNA: 77,1%; ABZ: 74,3%). Pain after shoulder arthroscopy was more severe compared to knee arthroscopy, both with and without repair of the anterior cruciate ligament. Most of the adverse symptoms decreased significantly (p ≤ 0.001) with time, demonstrating progressive recovery of the patient. Patient discomfort was more likely to occur in female than in male patients, and female patients were more likely to be dissatisfied with the progress of recovery. The risk of experiencing adverse symptoms after anesthesia was higher for female than for male patients; this was most apparent for feeling cold (odds ratio, OR 4.08) and nausea and vomiting (OR 3.45). Younger patients (18-40 years) were more likely to express discomfort than both groups of older patients (41-60 years and 61-89 years). Accordingly, younger patients had lower satisfaction levels with respect to both anesthesia and overall perioperative care, and the progress of recovery. Postoperative nausea and vomiting (PONV) were linked to younger age, female sex, and longer procedure times (>40 min)., Conclusion: The individual analyses delivered plausible results, which support the validity of the ANP. The ANP may also be used for assessment of postoperative discomfort and patient satisfaction in the setting of outpatient surgery. In view of the short time interval between the two measurement points, the ANP for outpatients could in future be reduced to a single postoperative questionnaire., (© 2021. Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Unlabelled: The laryngeal mask airway (LMA; Laryngeal Mask Company, Henley-on-Thames, UK) is an established airway device, whereas the laryngeal tube (LT) is relatively new and therefore not as well investigated. Therefore, the purpose of the present prospective, randomized, controlled trial was to compare the LT with the LMA in routine clinical practice. In 50 patients undergoing general anesthesia for minor routine surgery, standardized anesthesia was induced and maintained with alfentanil and propofol. Patients were randomized to controlled ventilation (fraction of inspired oxygen = 0.4; fraction of inspired nitrous oxide = 0.6; tidal volume = 7 mL/kg; respiratory rate = 10 breaths/min) with the LT (n = 25) or the LMA (n = 25). Oxygen saturation was recorded before the induction of anesthesia and after the administration of oxygen. After 2 and 10 min of ventilation with the LT or LMA, oxygen saturation, end-expiratory carbon dioxide, expiratory tidal volume, and peak airway pressure were recorded. Capillary blood gas samples were taken before the induction of anesthesia and after 10 min of ventilation. Time of insertion and airway leak pressure of each device were measured. The time of insertion was comparable with both devices (LT versus LMA, median 21 s versus 19 s; P = not significant). Blood gas samples and ventilation variables revealed sufficient ventilation and oxygenation with either device (P = not significant). Peak airway pressure (LT, 17 +/- 3 cm H(2)O; LMA, 15 +/- 3 cm H(2)O) and airway leak pressure (LT, 36 +/- 3 cm H(2)O; LMA, 22 +/- 3 cm H(2)O) were significantly (P < 0.05) higher when using the LT compared with the LMA. In conclusion, using the LT and LMA resulted in comparable ventilation and oxygenation variables in this model of ASA physical status I and II patients undergoing routine surgical procedures. The newly developed LT may be a simple alternative device to secure the airway., Implications: The laryngeal tube, a newly developed airway device, and the laryngeal mask airway were used to ventilate patients in the operating room. Both airway devices proved to be effective and safe; however, the laryngeal tube allowed greater airway pressure during ventilation.

Objectives: Gastric inflation and regurgitation of stomach contents are major hazards of bag-valve-mask ventilation in an emergency. The purpose of our study was to determine lung ventilation and gastric inflation when using the bag-valve-face mask, laryngeal mask, and combitube with different sizes of self-inflating bags (max. volume: 700, 1100, 1500 ml)., Methods: Twenty-six training emergency doctors without prior extensive training in emergency airway management volunteered for our study and ventilated a bench model simulating an unintubated respiratory arrest patient with bag-valve-face mask, laryngeal mask, and combitube using paediatric, medium size, and adult self-inflating bags. Lung and gastric tidal volume, as well as lung and gastric peak airway pressure were measured with respiratory monitors and a pneumotachometer., Results: When using either the combitube or the laryngeal mask, the paediatric vs. medium-size and adult self-inflating bag resulted in significantly (P < .001) lower mean +/- SEM lung tidal volumes (328 +/- 34 vs. 626 +/- 65 vs. 654 +/- 69 ml; and 368 +/- 30 vs. 532 +/- 48 vs. 692 +/- 67 ml, respectively). No gastric inflation occurred with the combitube, while gastric inflation was comparably low when using the laryngeal mask with either ventilation bag (3 +/- 2 vs. 7 +/- 4 vs. 6 +/- 3 ml; P = NS). The paediatric vs. medium-size and adult self-inflating bag in combination with the bag-valve-face mask resulted in comparable lung tidal volumes (250 +/- 23 vs. 313 +/- 24 vs. 282 +/- 38 ml; P = NS); but significantly (P < .01) lower gastric tidal volumes (147 +/- 23 vs. 206 +/- 24 vs. 267 +/- 23 ml)., Conclusions: Both the laryngeal mask and the combitube proved to be valid alternatives for the bag-valve-face mask in our experimental model. The medium size self-inflating bag seems to be adequate when using either the laryngeal mask or the combitube.

The purpose of this study was to assess the levels of lung and gastric tidal volumes paramedics achieve when performing ventilation with bag-valve-mask, laryngeal mask, and Combitube. Twenty paramedics performed ventilation with a bag-valve mask, laryngeal mask, and Combitube in a bench model simulating an unintubated cardiorespiratory arrest patient. Lung and gastric tidal volumes and lung and gastric peak airway pressures were subsequently measured. The results showed that mean +/- SEM lung tidal volumes were significantly higher with the laryngeal mask and Combitube compared to the bag-valve-mask (701 +/- 264 vs. 742 +/- 311 vs. 353 +/- 110 mL, respectively). No gastric inflation occurred with the Combitube; gastric inflation was significantly lower with the laryngeal mask compared to the bag-valve-mask (25 +/- 15 vs. 230 +/- 25 mL, respectively). Both the laryngeal mask and Combitube proved to be valid alternatives for bag-valve-mask ventilation in our bench model simulating an unintubated patient with cardiorespiratory arrest.

Samples of wheat, rye and barley from previous harvests, some of them dating back even to the past century and placed at the authors' disposal by a number of seed growers and governmental research institutions, were examined for their cadmium content by AAS or ICP-AES. Although no statistically valid data could be obtained owing to the low number of samples, it should nevertheless be stressed that the cadmium content found in cereal samples from harvests of the past were within the range of present-day wheat samples. Thus, the variation in wheat samples from former harvests was 20-100 micrograms/kg which is coincident with an average cadmium content of 50-60 micrograms/kg measured in 2000 what samples from the harvests of the last 10 years as determined in a special survey by the Federal Ministry of Food, Agriculture and Forestry. Comparison of the results for cereals samples from harvests of the past and the samples of the survey conducted by the Ministry does not indicate a trend towards a continuously rising cadmium contents of bread cereals.

A procedure is described for the residual analysis of eight pyrethroid insecticides at levels of 2-5 micrograms/kg. Residues are extracted from cereal grains, flour or bread with a mixture of acetonitrile/water (2 + 1) and are partitioned into petroleum ether. Clean-up is performed by gel permeation chromatography on Bio-Beads S-X3 and an additional Florisil column. Electron capture gas liquid chromatography on a non-polar SE-30 capillary column separates the isomers of the compounds. Under the conditions used in the experiments with cyfluthrin, cypermethrin, deltamethrin, fenvalerate, and permethrin, the compound levels in rye and wheat did not decrease significantly. Losses during milling and baking were small. Consequently, pyrethroid insecticides remain effective in grain stored over a long period of time. However, considerable residues result in the milled fractions as well as in different types of bread.