Atrial reflexes during high frequency oscillatory ventilation.
High frequency oscillatory ventilation (HFOV) is a new method of artificial ventilation which has been advocated for use in critically ill individuals. It alters the discharge in pulmonary stretch receptors (SAR) from a phasic to a continuous pattern. Since some cardiovascular neurones in the medulla are influenced by the discharge from SAR, experiments were undertaken to determine whether the reflexes from the left atrial (volume) receptors (LAR) were influenced by HFOV. The reflex increases in heart rate and urine flow which result from activation of the (LAR) were examined during both intermittent positive pressure ventilation (IPPV) and HFOV. In five dogs, the increase in heart rate was 23.9 +/- 4.3 and 24.5 +/- 5.4 beats/min during IPPV and HFOV, respectively. In six dogs the response of an increase in urine flow was examined and this response also was not altered by HFOV. It is concluded that the integrity of these reflexes was unaffected by HFOV in the anesthetized dog model.
D000818:Animals; D001794:Blood Pressure; D004231:Diuresis; D004285:Dogs; D006325:Heart Atria / Q000294:innervation*; D006339:Heart Rate; D008465:Mechanoreceptors / Q000502:physiology*; D009318:Natriuresis; D011312:Pressure; D012018:Reflex / Q000502:physiology; D012121:Respiration, Artificial / Q000379:methods