[Chemosensory Evoked Changes of Breathing Pattern During Propofol-induced Sedation]. / Chemosensorisch evozierte Atemänderungen während zweier Propofol-induzierter Sedierungsstadien.

BACKGROUND: The affective valence of an olfactory stimulus will be encoded in its respiratory response. Unpleasant odors shorten the inhalation of the first stimulated breaths in wakefulness and sleep. The aim of the present study was to assess the effekt of intravenous anesthetic propofol on the chemosensory evoked changes of breathing pattern. MATERIAL AND METHODS: 13 ASA 1/2 patients got intranasal chemosensory stimuli (H2S and CO2) by flow-olfactometer during "deep" (EEG-based bispectral analysis, BIS:≤60) and "moderate" (BIS>60) propofol-induced sedation with preserved spontaneous breathing. The duration of the in- and exhalation was analyzed for 5 breaths before and for 2 breaths after the onset of stimulation. RESULTS: During deep sedation respiratory reactions were observed only by CO2 irritation. During moderate sedation respiratory responses were evoked by H2S stimuli, too. In moderate sedation extensions of the inhalations of the first breath after both the unpleasant pure olfactory H2S stimuli and the trigeminal stimuli were more frequent than reductions. CONCLUSION: Olfactory stimuli change the breathing only during moderate sedation, trigeminal stimuli during deep and moderate propofol-induced sedation. In opposite to both wakefulness and sleep the duration of inhalation is often extended by H2S-stimuli during moderate sedation.

[The regularity of the breathing pattern of both sitting and reclining adults is not different]. / Die Regelmäßigkeit der Ruheatmung sitzender und liegender Erwachsener unterscheidet sich nicht.

BACKGROUND: A prestimulatory regular breathing is required for the respiration-olfactometry. In a sitting position, just about every second prestimulatory breathing sequence fulfilled this requirement checking off -line. It should be examined whether breathing in reclining position is more regular. METHODS: The coefficients of variation of the time parameters of breathing in reclining and sitting position during 30 min were determined and compared. RESULTS: Breathing regularity did not increase in reclining position with 48 healthy persons (age group 1: 18 to 30 years, n = 24, 18 women; age group 2: > 55 years, n = 24, 13 women). The age and gender had no eff ect on the proportion of regular breathing. With 7 persons, the yield of 5 on each other following regular breaths was inadequate. Additionally one person excluded from our study was not able to breathe regularly without interruptions. CONCLUSION: The respiration-olfactometry cannot be performed in each person. It is not more successful in reclining than in sitting position.

[Hyposmics have less evoked respiratory orienting reactions than normosmics]. / Hyposmiker haben weniger evozierte respiratorische Orientierungsreaktionen als Normosmiker.

BACKGROUND: Respiratory orienting reactions after olfactory stimulation can be seen as an indicator of an intact olfactory processing. Olfactory stimuli have to be recognized and they have to be important for a subject in order to generate a respiratory orienting reaction. METHODS: Hyposmic patients were stimulated pre-nasally with one sub-threshold and two supra-threshold concentrations of hydrogen sulfide (H(2)S) using a flow olfactometer. Nasal respiration was measured unilaterally using a differential pressure transducer. The data were processed after digitalization with the LabView software package. Duration of inspiration (DIN) and duration of expiration (DEX) were used as test variables for the evaluation of a regular resting respiration or a poststimulation respiration complex (PRC), respectively. RESULTS: The rate of poststimulatory respiration alterations (47%) in hyposmic subjects was significantly higher than the rate of spontaneous changes after resting respiration (31%). The reaction rate was not stimulus concentration-dependent. In spite of the stimulus recognition poststimulatory respiration alterations were less often in hyposmic subjects compared to normosmic subjects. DISCUSSION: Maybe this is due to the reduced significance of perceptible odors for hyposmic persons.

[Gustatory input affects breathing pattern: a method for objectifying of gustatory perception]. / Geschmacksreize verändern das Atemmuster: Methodik zum objektiven Nachweis einer Schmeckwahrnehmung.

INTRODUCTION: There is currently no commercial tool available to examine gustatory perception objectively. We investigated whether early changes of breathing patterns can be evoked by gustatory stimulation, and whether there are differences between sweet, sour, salty and bitter stimulation. METHODS: Using a randomised design, 34 young adult subjects (15 male, 19 female; average age: 24.6 years, median: 23, minimum: 22, maximum: 33) with normal sense of taste were stimulated by supra-threshold taste solutions for approximately 6 s. A pressure sensor recorded nasal respiratory changes using LabView software. The interstimulus-interval was longer than 1 min depending on regular status of unstimulated breath. Durations of inspiration (DIN) and expiration (DEX) were analysed. Values outside the 95%-confidence intervals were defined as gustatory evoked changes. RESULTS: The rates of alteration differed significantly in the first, second and third post stimulatory breath. The rates were regarding to DIN between 25.87% and 36.49%, and regarding to DEX between 35.31% und 43.13%. Blank stimuli showed a rate between 5.97% and 8.96% in DIN and in DEX between 10.66% and 11.48%. There were no differences in reaction frequency between the four taste solutions. Every subject reacted to gustatory stimulation more frequently than to blanks. DISCUSSION: Like other sensory modalities, gustatory input is able to evoke early respiratory orienting responses. The reaction rate is not dependent on the hedonic component of the gustatory input, as has already been shown for respiration-olfactometry.

Quantification of lipids, liposomes, amino acids, and proteins by thermal ultramicrodigestion and an ultramicrocoulometric assay, based on the reaction of hypobromite with ammonia.

The quantification of nitrogen in organic material is described. It is based on a novel thermal ultramicrodigestion in combination with an ultramicrocoulometric quantification. The lower detection limit of the coulometric measurement is 0.5 microg nitrogen, which corresponds to 20 microg lipid, 3 microg glycine, or 4 microg protein. Therefore it is as sensitive as the frequently used Lowry method. In contrast to the Lowry protein determination it is not disturbed by detergents and most other interfering substances.