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Biomedical subjects

R Rauh

Publications and source records attributed to R Rauh.

9 recordsLinked to original sources
PubMed2007

Sildenafil affects olfactory function.

PURPOSE: Sildenafil is the first member of a new class of oral drugs effective for erectile dysfunction. However, approximately 20% of patients complain about nasal congestion after sildenafil administration. MATERIALS AND METHODS: Because nasal airflow and olfaction are closely linked, the sense of smell was evaluated in 20 young, healthy volunteers after the administration of 50 and 100 mg sildenafil, and placebo in a double-blinded, crossover study. Olfactory function was evaluated using a standardized and validated test (Sniffin' Sticks). To investigate a possible impact of G-protein beta3 subunit C825T polymorphism on the effect of sildenafil on olfaction the genotype of all subjects was determined. RESULTS: The effect of sildenafil on olfaction was only present at a dose of 100 mg but not at a dose of 50 mg sildenafil. The genotypes TT, CC and TC of the G-protein beta3 C825T polymorphism had no impact on the change in olfactory function. CONCLUSIONS: Higher sildenafil doses may produce decreased olfactory sensitivity.

Cross-Over Studies↗
PubMed2006

Weight gain associated with clozapine, olanzapine and risperidone in children and adolescents.

The study was aimed at the evaluation of weight gain associated with atypical antipsychotics and its clinical risk factors in children and adolescents. Weight and body mass index (BMI) of initially hospitalised patients treated with clozapine (n = 15), olanzapine (n = 15), and risperidone (n = 15) were prospectively monitored on a weekly basis for the first 6 weeks. Different clinical risk factors were tested for their association with weight gain in the three groups. All three groups experienced significant weight gain between baseline and endpoint (p < 0.0001). For all weight measures, planned comparisons were all significant between olanzapine vs. clozapine and risperidone, respectively. Average weight gain was significantly higher for the olanzapine group (mean = 4.6 kg, SD = 1.9) than for the risperidone (mean = 2.8 kg, SD = 1.3) and clozapine (mean = 2.5 kg, SD = 2.9) groups. Olanzapine and risperidone, but not clozapine, caused a disproportionately higher weight gain in children and adolescents in comparison to adults.

Adolescent↗
PubMed2002

Do preceding vasoconstrictions influence the 'inspiratory gasp test'?

Diabetic or other neuropathies can affect the autonomic innervations of vessels and heart. Using non-invasive and inexpensive autonomic tests, one can detect autonomic neuropathy. One of these tests is the inspiratory gasp response (IGR). It appears as a short reduction of skin blood volume (SBV) following deep inspiration (DI). Unfortunately, because of a high degree of variability of the study results, the clinical merits of this test have been questioned. However, there remains vagueness about underlying mechanisms or pitfalls. The aim of the study was to identify preceding vasoconstrictor episodes as putative pitfalls in assessing IGR. With regard to the hypothesis that a preceding vasoconstrictor episode may affect the amplitude of the following one, we investigated SBV in fingertips of 25 healthy test subjects (14 females, 11 males; mean age 24 years), using the photoplethysmographic technique. After adaptation to environmental conditions the subjects were instructed to perform five DI in various time lags (90, 30, 20 and 180 s). We found that the shorter the time interval to a preceding IGR, the lower the amplitude of the following IGR. After an interval of 180 s, the amplitude increased again. We conclude that this newly observed phenomenon might explain the contradictory results of the IGR test found in some earlier studies. We suppose that reduced IGR may depend on alterations in peripheral norepinephrinergic transmission processes (e.g. emptying of norepinephrine reservoirs). In clinical studies it should be ruled out that a diagnostically assessed IGR is influenced by a preceding vasoconstrictor episode.

Adult↗
PubMed2001

Influence of pneumoperitoneum and patient positioning on preload and splanchnic blood volume in laparoscopic surgery of the lower abdomen.

STUDY OBJECTIVE: To determine the hemodynamic effects of pneumoperitoneum and patient positioning during laparoscopic surgery of the lower abdomen. DESIGN: Prospective study. SETTING: University-affiliated medical center. PATIENTS: 10 ASA physical I and II female patients scheduled for laparoscopic surgery of the lower abdomen. INTERVENTIONS: Patients were anesthetized with propofol and an alfentanil infusion, then intubated, and normoventilated. MEASUREMENTS: After intubation, a transesophageal multiplane probe for measurements of right (RVESA) and left (LVESA) ventricular end-systolic and end-diastolic areas (RVEDA and LVEDA) and ejection fraction area (RVEFa, LVEFa) was introduced; heart rate (HR) and noninvasive blood pressure (BP) were recorded every minute. Ventilation was not changed during the measurements. A transvaginal ultrasound probe was inserted to measure the diameter of the common iliac vein. Measurements were performed 15 minutes after induction of anesthesia and while patients were in the supine position (P 0), 10 minutes after CO(2) insufflation to 10 mmHg IA pressure (P 10), 10 minutes after a further increase to 15 mmHg (P 15), 10 minutes after 20 degrees Trendelenburg (P 15 T), and 20 degrees reverse Trendelenburg positions (P 15 RT). Data are shown as medians, 25th to 75th percentiles, and comparisons between P 0, P 10, P 15, and P15 T were made with the Friedman test, followed by Wilcoxon test, when significant. Data at P 15 T, P 15 RT, and P 15 were compared using the Wilcoxon test, with a p-value < 0.05 regarded as significant. MAIN RESULTS: Pneumoperitoneum at 10 mmHg abdominal pressure caused a significant increase of LVESA by 78% (RVESA: 61%) and LVEDA by 48.5% (RVEDA: 45%). The diameter of the common iliac vein was decreased by 6%. A further increase of abdominal pressure to 15 mmHg led to an additional increase of 20% (LVESA) and 17% (LVEDA). Mean arterial pressure increased by a significant 7% at P 10, decreasing subsequently by 5% at P 15. The Trendelenburg position did not alter any hemodynamic findings. Reverse Trendelenburg position, however, caused a significant LVEDA-and RVEDA-decrease by 18% and 27%, respectively, and an increase in the diameter of the common iliac vein by 22%. The LVEFa and RVEFa decreased significantly after abdominal CO(2) insufflation by 18% each (P 10) without further change. CONCLUSIONS: The lithotomy position and subsequent pneumoperitoneum increased preload, probably as a result of blood shifting from the abdomen to the thorax by compression of splanchnic vessels caused by the pneumoperitoneum. Careful fluid management, maintaining low abdominal pressure, and use of the reverse Trendelenburg position are favored to prevent adverse hemodynamic effects in laparoscopic surgery.

Abdomen↗
PubMed2001

Influence of pneumoperitoneum and patient positioning on respiratory system compliance.

STUDY OBJECTIVE: To investigate the influence of pneumoperitoneum (PP) and posture on respiratory compliance and ventilation pressures. DESIGN: Prospective, single blind trial. PATIENTS: 10 female ASA physical status I and II patients scheduled for elective gynecologic laparoscopy. SETTING: University medical center. INTERVENTIONS: Anesthesia was performed as total IV anesthesia (TIVA) with propofol, alfentanil, and atracurium. After induction of anesthesia and orotracheal intubation, the lungs were ventilated to maintain partial pressure of CO(2) (P(ET)CO(2)) of 30 +/- 3 mmHg. Ventilation was kept constant. As gas mixture oxygen and air 1:1 was used without positive end-expiratory pressure (PEEP). MEASUREMENTS: Measurements were taken before and after creation of pneumoperitoneum with an intraabdominal pressure (IAP) of 10 mmHg, of 15 mmHg in 20 degrees head-down tilt, then in 20 degrees head-up tilt, and after deflation of PP. We determined peak inspiratory pressure (PIP), mean airway pressure (mPaw), P(ET)CO(2), expiratory minute volume (V(E)), heart rate (HR), and systolic (SBP), diastolic (DBP), and mean arterial pressure (MAP). Respiratory system compliance (C(eff rs)) was calculated as quotient of tidal volume (V(T)) and PIP. MAIN RESULTS: After creation of PP (IAP 10 mmHg), there was a significant increase of median PIP (3 cmH(2)O), mPaw (1 cm H(2)O) and arterial pressure (BP), (MAP by 7 mmHg), C(eff rs) decreased by 6 mL. cm H(2)O(-1). Increase of IAP to 15 mmHg led to a further increase of PIP (2 cm H(2)O) and mPaw (1 cm H(2)O), and a further decrease of C(eff rs) by 5 mL cm H(2)O(-1); BP decreased (MAP by 5.5 mmHg). Head-up or head down positions showed no significant hemodynamic or pulmonary changes. P(ET)CO(2)increased from 29.5 to 36 mmHg at an IAP of 15 mmHg, but then no further changes were noticed. Five minutes after deflation of pneumoperitoneum all values returned to baseline levels. CONCLUSIONS: Creation of PP at an IAP of 15 mmHg reduced respiratory system compliance, and increased peak inspiratory and mean airway pressures, which quickly returned to normal values after deflation. Head-down or head-up position did not further alter those parameters.

Adult↗
PubMed2001

[Hemodynamic effects of pneumoperitoneum in lithotomy position].

AIM OF STUDY: The study investigates the haemodynamic effects of the varying intraabdominal pressures and patient positions during gynecological procedures employing pneumoperitoneum in lithotomy positions. METHODS: TEE was used to determine end-diastolic and end-systolic left ventricular surface areas and ejection fractions were calculated from these data. To evaluate intraabdominal volume shifts the diameter of the internal iliac vein was measured by mean of vaginal ultrasound. RESULTS: In the horizontal lithotomy position both LVEDA and LVESA increased when intraabdominal pressure increased by 10 and 15 mmHg, respectively. LVAEF significantly decreased when intraabdominal pressure increased by 15 mmHg. Also DVII decreased. In Trendelenburg position there was no change in LVEDA, LVESA, LVAEF and DVII. In Anti-Trendelenburg position LVEDA and LVESA decreased. However, LVAEF remained constant and DVII increased. CONCLUSION: The increase of the intraabdominal pressure in the lithotomy position results in an increase in intrathoracic volume and an decrease in LVAEF via elevation of the the lower extremities and compression of the splanchnic vessels. There are no changes in Trendelenburg position. However, in Anti-Trendelenburg position, gravity results in a decrease in intrathoracic blood volume. In the decreased, dilatated heart the increase in intrathoracic volume may increase myocardial wall tension and hence oxygen demand, ultimately leading to an acute heart failure. As a result laparoscopic procedures in horizontal lithotomy position should be avoided in patients with dilatative cardiomyopathy.

Adolescent↗
PubMed1996

Transesophageal echocardiography in patients with focal cerebral ischemia of unknown cause.

BACKGROUND AND PURPOSE: Identification of cardioembolic stroke is often limited by the difficulties involved in the detection of thrombi or the risk factors for thrombus formation. Patients in sinus rhythm with nondiagnostic transthoracic echocardiogram (TTE) and without carotid artery stenosis represent a subset in whom diagnostic recommendations are lacking. The aim of this study was to determine the value of transesophageal echocardiography (TEE) for diagnosis and therapy in this population. METHODS: Thirty patients with the characteristics described above were studied prospectively with the use of blood analysis, TTE, TEE, and Holter monitoring (in patients with atrial thrombus). RESULTS: TTE was abnormal in 16 of 30 patients, but no embolic source was identified. TEE disclosed left atrial appendage thrombus in 3 of 30 patients, atrial septal aneurysm in 2 of 30 patients, patent foramen ovale in 7 of 30 patients, and aortic plaques in 19 of 30 patients. The Tee resulted in a change of therapy in 3 of the 30 patients studied. CONCLUSION: This study demonstrates that TEE is a helpful diagnostic tool in delineating the risk of cardioembolic stroke and demonstrates significant pathology even in a subset of patients deemed to be at low risk. This additional new information led to a substantial change in therapy in 3 of 30 patients.

Adult↗