Acta Physiol Hung
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Comparative Study
Cough reflex in rabbits 24-h and 48-h after sulphur dioxide breathing.
The cough reflex elicitability (CRE), cough reflex strength (CRS) and Hering-Breuer inflation reflex (HBIR) were studied in 51 anaesthetized (Pentobarbital Spofa, 30 mg/kg, i.v.) female rabbits 24-h and 48-h after SO2 breathing. To provoke cough, the interior of the trachea and carina were stroked with a polyethylene catheter. To elicit the HBIR, the lungs were inflated to 1.0 kPa intratracheal pressure. ⋯ The CRE, CRS and HBIR obtained 24-h and 48-h after SO2 breathing were compared with correspondent values of control animals. It was found, that CRE and HBIR were fully recovered 24-h after SO2 breathing, but the CRS was still decreased, however, there were no significant differences in CRE, CRS and HBIR between animals 48-h after SO2 breathing and control animals. It can be concluded, that decrease of the CRS 24-h after SO2 breathing is not due to slowly adapting stretch receptors block of airways.
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Pulmonary arterial hypertension develops in acute respiratory failure and mostly an enhanced PADd-PCWP gradient has an important effect on the outcome of that complication. Considering that this critical state of septic burned patients may last for weeks, the long-term direct monitoring of pulmonary arterial blood pressure with indwelling Swan-Ganz catheter is impossible because of the high risk of endocarditis. Therefore, the aim of this study was to elaborate a noninvasive method to estimate the pulmonary arterial hypertension. ⋯ Close correlations have been found between PAPm and PO2/FiO2 (r = 0.75), as well as between PAP values and some noninvasively measured hemodynamic data. Using these interrelations: 1) regression equations for PAPs., PAPm, PAPd, PCWP, PVRI were elaborated (r values: 0.855, 0.869, 0.681, 0.644, 0.817 respectively); 2) discriminant analysis with noninvasive parameters correctly classified the cases at critical PAPd-PCWP gradient (greater than 4 mm/Hg) in 84%. These results suggest that a continuous noninvasive hemodynamic and blood gas monitoring completed with a periodic bedside computer analysis of the PC-processed data for calculation of the pulmonary arterial pressure may be enough for the therapy during the long-term critical periods.
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The authors studied relationship between the antitussic and analgesic activity of substances. The antitussic effect of codeine, tilidine, tramadol and pentazocine has been studied in nonanesthetized healthy cats. The drugs except tilidine, were administered intraperitoneally in a dose of 10 mg/kg body weight. ⋯ A significant decrease of the subsequent cough parameters was observed after the application of codeine, tilidine, tramadol and pentazocine. Naloxone given 5 min before the application of the drug has not prevented the cough-suppressing effect due to codeine. Naloxone alone administered in a dose of 1 mg/kg body weight has not significantly influenced the experimentally-induced cough reflex in nonanesthetized cats.