|
KMID : 0351619700110020357
|
|
Kyungpook Medical Journal
1970 Volume.11 No. 2 p.357 ~ p.367
|
|
|
Effect of Position on Pulmonary Gas Volume, ECG and Blood Pressure
|
|
|
|
|
Abstract
|
|
|
The changes of the pulmonary air volumes according to the various postural changes were measured. At the same time the ECG was recorded and the systolic and diastolic blood pressures were measured by .the auscultatory method.
Total of 116 university students were employed for this purpose. The range of the age of the subjects were from 19 to 22 years old.
The average body weight was 59kg and stature 170cm. In the sitting position, the mean vital capacity (VC) was 4098 ml and this value was closely similar to that of the predictive value derived from tile West equation. the percentage of the residual volume (RV) to the total lung capacity (TLC) was 22.7
The change of the TLC and VC according to the various body postures was apparent, but that of the RV was relatively unchanged with the postural changes.
In the vertical head down tilt, a significant change of 15.6% decrease of the VC was obtained comparing to that of the sitting position.
In the study of the ECG changes during the tilting, the initial instantaneous sinus bradycardia within 10 seconds from the beginning was common findings regardless of the direction of the tilting of the body, and the bradycardia disappeared thereafter.
Duriug 1 to 2 minutes from the beginning in the vertical head down tilting, the short term relative sinus tachycardia was observed. And this finding was assumed as an Bainbridge reflex induced by the increased venous return to the right ventricle.
No abnormal ECG findings were noted except those of flatness of P wave and insignificant elevation of R-ST segments in the charges of systolic blood pressure, the average value in the sitting posture was 124.7 mmHg. The variations of systotic blood pressure according to the barious postural changes were between 98.2% and 101.8% comparing with that of the sitting, but these were statistically insignificant.
On the contrary, the diastloic blood pressure was significantly increased during the postural changes in the position of the supine and vertical head down with comparing with the sitting position.
The average diastolic blood pressure in the sitting was 73.7 mmHg, and this was increased to 109.6% at the initial vertical head down tilt from the sitting position.
This rise in pressure was considered to be caused by the increased hydrostatic pressure to the left ventriele from the upside down position of the body. The hydrostatic pressure would be equal to that of a theoretical column which has the height of equal distance from the foot to the heart.
This rise in pressure was readjusted to the initial range within 3 to 4 minutes in the posture. It was assumed that this regulation of the diastolic pressure was induced by the pressorreceptor by decreasing the peripheral vascular tone.
|
|
|
KEYWORD
|
|
|
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|
|
|