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T W Fengler

Publications and source records attributed to T W Fengler.

5 recordsLinked to original sources

The clinical suitability of laparoscopic instrumentation. A prospective clinical study of function and hygiene.

On the basis of experience gained from 6,000 laparoscopies (73% cholecystectomies) at the Moabit Hospital in Berlin, we carried out a cohort study to analyze the failure rate and decontamination of labeled "tracer" instruments processed in three test trays that were each subjected to 100 cycles. The majority of repairs focused on the functional parts of separable scissors and damaged or lost components. At 4%, the repair index after laparascopic use was less than that of a previously documented investigation period covering 1990 to 1996. A comparison of the costs of disposable and reusable instruments showed that reusable instruments were more cost-effective by a factor of > or =10, indicating that the price gap reported in our previous calculation for 1992 and 1994 has closed only slightly. After 100 cycles, we found traces of proteinaceous material in the eluate on every fourth instrument inspected (eight of 32); half of them (four) gave a positive reading when tested with a hemoglobin pseudoperoxidase test stick. It must be said, however, that similar residual contamination has been found on instruments used in conventional open surgery, with no indication of clinical relevance. This study was designed to examine the clinical suitability of laparoscopic instruments in terms of function and hygiene. Improvements in instrument design and cleanability must focus in particular on the reproducibility of cleaning results, because cleaning is the most important step in processing sterile supplies. As the number of minimally invasive operations has risen considerably, a mere visual check no longer meets the requirements prescribed by modern quality assurance. A multicenter study of residual proteins found on tracer instruments in all surgical fields is now in progress.

Cost-Benefit Analysis↗

Sterile and economic instrumentation in laparoscopic surgery. Experiences with 6,000 surgical laparoscopies, 1990-1996.

BACKGROUND: Because so many common surgical problems can now be addressed by the laparoscopic approach, the issue of sterile processing has to be reconsidered. METHODS: Selected laparoscopic instrumentation was analyzed regarding wear and tear and decontamination after sterile processing following 6,000 surgical laparoscopies carried out between 1990 and 1996 at the Academic Hospital Moabit, Berlin. RESULTS: Fewer than 7.9 (parts of) instruments failed per 100 laparoscopies. Most of the repairs involved scissors. The main problems were blunting, burnt or disconnected electromechanical components, defective insulation, and damaged or lost parts of dismantable instruments. Residues of human blood proteins were detected on a few instruments. The effect of intraluminal rinsing was documented by measuring the iron content (as an indicator for blood contamination). A comparison of costs showed that it was >10 times cheaper to use instrumentation with reusable components. CONCLUSIONS: The sterile processing of economic reusable instrumentation for laparoscopies needs staff well trained in sterile supply. Instrument design should allow easy dismantling and rinsing of internal parts. Insulating compounds present a problem for decontamination. Disinfection with aldehydes before cleaning the lumina of instruments must be avoided because protein coagulation will occur. A tube-in-tube concept for tubular instruments offering compatibility should be favored.

Data Collection↗

[Laparoscopic instruments in practical clinical tests--prospective study of functional aspects and residual contamination].

Wear, tear, and possible contamination after 100 clinical cycles of three test trays were investigated on laparoscopic "tracer" instruments in a prospective clinical study. Failure was below 4 per 100 laparoscopies, and remaining contamination was detected after passing 100 cycles in 20%, which happened to control instruments from open surgery as well. Further clinical data of contamination levels for apparently clean instruments must be collected to evaluate and correlate to microbiological testing.

Cohort Studies↗

Continuous monitoring of fetal oxygen saturation by pulse oximetry.

OBJECTIVE: To compare spectrophotometric saturation values of fetal blood sampling to the saturation readings by pulse oximetry. METHODS: During a clinical trial, fetal oxygen saturation was monitored during labor by a fetal oxisensor and a fetal pulse oximeter. Fifty-one fetal scalp blood samples were assessed because of abnormal fetal heart rate (FHR) patterns. The pulse oximeter displayed only signal quality readings. The investigator had to perform adjustments if signal quality fell below 50%. After delivery, the saturation at the moment of fetal blood analysis could be read from a printout and compared to the saturation values of scalp blood sampling. RESULTS: The share of usable signal time was 51% overall, but only 40% in the 20-minute period during fetal blood sampling. Comparison with the reference method resulted in a median deviation of 6% (tenth percentile -10%; 90th percentile 18%) for pulse oximetry. The correlation coefficient between saturation values by pulse oximetry and fetal scalp blood sampling was 0.67. The correlation coefficient with the partial pressure of oxygen and oxygen saturation by pulse oximetry was 0.61, whereas it was 0.88 between partial pressure and saturation from the spectrophotometric analysis of the scalp sample. CONCLUSIONS: Fetal pulse oximetry corresponds satisfactorily to results from fetal blood analysis. Low invasiveness and continuous monitoring are the advantages of this method. At present, the available sensor generates only a limited amount of signal time. However, in combination with FHR monitoring, pulse oximetry promises greatly improved detection of fetal hypoxia.

Female↗