[Hemodynamics associated with sleep disorders in anesthetized dogs].
Pulsus paradoxus, systolic pressure fluctuation greater than 10 mmHg during the respiratory cycle, is a well-known phenomenon. I found another fluctuation of a circulatory factor, the volume pulse wave (VPW) recorded with a pulse oximeter. I called this phenomenon "VPW fluctuation during the respiratory cycle." Using mongrel dogs, I studied the relationship between the amplitude of esophageal pressure and the degree of fluctuation of systolic pressure and VPW. I found strong correlations between the amplitude of esophageal pressure and the degree of fluctuation of systolic pressure (r = 0.992-0.998, p < 0.001, n = 5). I also found strong correlations between the amplitude of esophageal pressure and the degree of fluctuation of VPW (r = 0.985-0.995, p < 0.001, n = 5). These findings, especially the latter data, show that we can measure three respiratory variables from a pulse oximeter. These are: respiratory rate, intrathoracic pressure and O2 saturation. Although these findings were obtained experimentally, they might apply to clinical studies, especially studies of sleep disorders.
Kimura
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Second Department of Internal Medicine, Hiroshima University School of Medicine, Japan.
D000758:Anesthesia; D000818:Animals; D001794:Blood Pressure; D004285:Dogs; D004947:Esophagus / Q000503:physiopathology; D006439:Hemodynamics; D010092:Oximetry; D011312:Pressure; D012119:Respiration; D012891:Sleep Apnea Syndromes / Q000503:physiopathology*