Publications (2)3.76 Total impact
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Article: Aerosol delivery by an ultrasonic nebulizer during different mechanical ventilation settings in a lung model--a pilot study.
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ABSTRACT: Aerosol delivery of Iloprost is a promising therapeutic approach. The aim of this study was to determine the output of an ultrasonic nebulizer in different ventilation set-ups at the tip of different endotracheal tubes. In set-up A, an ultrasonic nebulizer was connected directly to the endotracheal tube. In set-up B, the nebulizer was incorporated into the inspiratory limb of the ventilator circuit; a bypass arrangement allowed to selectively direct the expiratory air discharged from the model lung. The test lungs were ventilated through a standard endotracheal tube (ET) and through a double-lumen tube (DLT). The nebulizer was filled with 5 ml of a Tc-99m 0.9%-NaCl solution. After nebulization, distribution of radioactivity was detected by gamma scintigraphy. Set-up A, ventilation in volume-controlled mode (VCV) via an ET: Delivered dose (1.61 +/- 0.41 ml), nebulization time 10.13 +/- 1.71 min. Set-up A, pressure-controlled ventilation (PCV), via a DLT: Delivered dose (1.33 +/- 0.88 ml), nebulization time 13.27 +/- 2.58 min. Set-up B, VCV mode via an ET: Delivered dose (1.57 +/- 0.44 ml), nebulization time (25.9 +/- 3.8 min). Set-up B, PCV mode, via a DLT: Delivered dose (1.3 +/- 0.17 ml), nebulization time (25.6 +/- 4.0 min). Set-up B did not yield a significantly higher output (p < 0.05), but the nebulization time was significantly longer (p > 0.05) compared with set-up A. Set-ups which involve connecting the nebulizer directly to an ET or a DLT exhibit sufficient output of aerosol and short nebulization times.Drug Design, Development and Therapy 01/2009; 2:1-7. · 2.88 Impact Factor -
Article: Prospective investigation into the influence of various stressors on skin impedance.
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ABSTRACT: The control mechanisms during general anesthesia include circulation parameters and vegetative reactions. A possible way to quantify vegetative reactions is to measure the impedance of the skin. An activation of the eccrine sweat glands via sympathetic sudomotor fibers induces a secretion of sweat, which generates a drop in skin impedance. The aim of the present study was to investigate the influence which different stressors and measurement electrodes have upon skin impedance. The changes in skin impedance and were measured after application of various stimuli (T1 value at rest, T2 acoustic stimulus, T3 visual stimulus, T4 tactile stimulus, T5 pain stimulus, T6 Valsalva manoeuvre, T7 forced inspiration/expiration). About 62 awake subjects underwent four standardized test sequences, during which several types of electrodes and recording sites (palmarly, plantarly) were explored. All physiological (T6-T7) and external stimuli (T2-T5) led to significant changes in skin impedance (14.9 +/- 18.2 kOmega) and heart rate. These changes happened independently of BMI, gender and measurement electrode types. The time it took to react to the stimuli was significantly shorter for palmar applications than that obtained from plantar sites. The reaction times were as follows: palmarly 1.2 +/- 0.5 seconds for solidgel electrodes and 1.15 +/- 0.5 seconds for hydrogel electrodes, plantarly 2.3 +/- 1.0 seconds for solidgel electrodes and 2.21 +/- 1.2 seconds for hydrogel electrodes. The forced inspiration and expiration manoeuvres generated greater variations in skin impedance than did pain stimulus and acoustic stimulus. Measurements that were performed with solidgel electrodes revealed significantly greater average decreases in skin impedance following exposure to a stimulus. External, but primarily also physiological stressors, generate direct and reproducible variations in skin impedance. Solidgel ECG electrodes should be used for all measurements.Journal of Clinical Monitoring and Computing 03/2008; 22(1):67-74. · 0.89 Impact Factor
