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Biomedical subjects

R Keim

Publications and source records attributed to R Keim.

6 recordsLinked to original sources
PubMed2002

[Universal newborn hearing screening program in Würzburg. Experience with more than 4000 newborns and the influence of non-pathological factors on the test results].

BACKGROUND: The BERAphon(R) method employing a special headphone and the time-course step-stimulus algorithm offers a quick and reliable tool for universal hearing screening in newborns. An ABR-based universal newborn hearing screening program has been established in Würzburg since August, 1997. Until August 2001, 4115 newborns have undergone primary and/or control-screening with the BERAphon(R). The validity of this method was further examined by testing the effects of non-pathological factors such as gender, age, Apgar score, pH value of the umbilical cord, head circumference and duration of pregnancy on the ABR wave V latency in 415 infants. RESULTS: Out of 3930 infants who were primary screened, 27 infants were diagnosed to have hearing loss. Furthermore, hearing loss was detected in 35 out of 185 infants referred for control screening. Non-pathological factors showed a minor effect on the test results. Apgar score, gender or chronological age did not have any significant effects on the latency of wave V. Duration of pregnancy, pH value of the umbilical cord or head circumference showed a significant but weak correlation with wave V latency. CONCLUSIONS: Only non-pathological factors related to maturation had a minor effect on ABR measurements using the time-course-step-stimulus algorithm. The BERAphon(R) method has proven to be a reliable, robust method giving information related to the hearing threshold and accordingly can be used reliably for hearing screening in newborn infants.

Audiometry, Evoked Response↗
PubMed2000

[Universal hearing screening of newborn infants with the BERA-phone].

BACKGROUND: Unidentified and untreated early infant hearing loss leads to speech-language deficits as well as to cognitive, intellectual, emotional and psychosocial handicaps. Targeted hearing screening programs may miss approximately 50% of all hearing impaired children. METHODS: In an universal hearing screening program with a two stage protocol, 1349 newborns were examined using the CRESCENDO Newborn Hearing Screener according to Finkenzeller and a clinical ABR system operating with a time course step stimulus algorithm. RESULTS: Five newborns that failed the two stage screening protocol were diagnosed as hearing impaired so that therapy was initiated before the age of six months. The specificity of the method was 98.8%. The CRESCENDO method only required a short examination time and was easy to apply. CONCLUSIONS: Hearing screening programs using ABR offer advantages when compared to evoked otoacoustic emission testing. ABR threshold detection with the time course step stimulus algorithm is a quick and easy to apply method with high specificity that can be recommended for newborn hearing screening.

Algorithms↗
PubMedDate not supplied

Extracorporeal circulation in sheep with normal bleeding time using a surface heparinized circuit.

Bleeding due to systemic heparinization represents the major side effect of extracorporeal respiratory support. In the present animal study, a surface heparinized system (Carmeda Biological Active Surface) was applied to assess the feasibility of prolonged perfusion at low circulating heparin levels. Eight sheep divided into two groups: group A (5 animals) and group B (3 animals) underwent venovenous bypass using a heparin coated surface circuit. The following protocol was used: a) 24 hours at high heparin dose (30 to 100 U/kg/hr with an ACT [activated coagulation time] three to four times normal); b) 24 hours at low heparin dose (3 to 8 U/kg/hr with an ACT within the normal range); c) 24 hours at high heparin dose. Group B animals also received fresh frozen sheep plasma (14 ml/kg/day). During Period b, the clotting times were within baseline range. The bleeding time showed a dramatic decrease after change from a to b (27.9 +/- 3 minutes vs. 10.2 +/- 5.6 minutes). There was a negative relationship between antithrombin III (AT III) and thrombin coagulase time (TC); the latter is considered to be an aspecific indicator of circulating fibrin(ogen) degradation products. Maintaining AT III over 70%, TC changes were only minor. The use of the bioactive heparin surface allowed the performance of a 24 hour bypass, with normal coagulation times, at low circulating heparin levels.

Animals↗