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Christian Koch

Publications and source records attributed to Christian Koch.

20 records · Page 2Linked to original sources

Determination of the acoustic output of a harmonic scalpel.

The acoustic output of a harmonic scalpel was experimentally determined, and both the airborne ultrasound and the ultrasound transmitted in water were taken into account. The sound pressure level of airborne ultrasound was measured with a microphone and an artificial head, so that the free-field value and the sound level at the entrance at the bottom of the cavum conchae of the ear could be determined. The derived output power in water was obtained from a hydrophone measurement. The results were strongly influenced by cavitation effects, and it is shown that the power values with and without cavitation differ by more than a factor of 5. The measurement of acoustic output parameters forms the basis for describing the performance of the devices and for an assessment of the risk of harmful bioeffects on both the operator and the patient.

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Meropenem in cystic fibrosis patients infected with resistant Pseudomonas aeruginosa or Burkholderia cepacia and with hypersensitivity to beta-lactam antibiotics.

OBJECTIVE: To assess the efficacy and safety of meropenem, administered on a compassionate basis to 62 cystic fibrosis (CF) patients (age: 24plus minus6 years) with hypersensitivity reactions to beta-lactam antibiotics and/or infection by bacteria resistant to other antibiotics. METHODS: Fifty-seven patients were chronically infected with Pseudomonas aeruginosa and 5 with Burkholderia cepacia. In total, 124 courses (1 to 6/patient) of meropenem, 2 g three times a day by intravenous infusion (10 to 15 min) for 14 days, were administered. RESULTS: During treatment for P. aeruginosa the mean increase in pulmonary function (as a percentage of the predictive values) was 5.6% for FEV1 (forced expiratory volume in the first second) and 8.6% for FVC (forced vital capacity). C-reactive protein and erythrocyte sedimentation rate (ESR) and leukocyte count decreased significantly. In courses administered for chronic infection with B. cepacia the post treatment FEV1 and FVC values were higher than the pre-treatment values, and all the inflammatory parameters decreased. The geometric means of minimal inhibitory concentration (MICs) (microg/mL) for P. aeruginosa (B. cepacia) were: tobramycin 6 (59), ciprofloxacin 1.2 (9.7), piperacillin 49 (16.3), ceftazidime 26 (23), aztreonam 26 (35), imipenem 6.4 (not determined) and meropenem 5.1 (4.8). No statistically significant increase in the MICs of meropenem for either pathogen occurred during therapy. Of the 124 courses, 115 were tolerated without any clinical complaint. The following side effects were observed: nausea (0.8%), itching (4%), rash (3.2%), drug fever (1.6%). CONCLUSIONS: Meropenem proved to be a valuable drug in the treatment of CF patients with chronic pulmonary infection with multiresistant P. aeruginosa and B. cepacia and with hypersensitivity reactions to other beta-lactam drugs.

Journal Article↗