指尖容積脈波による母体循環動態からみた分娩時の安楽体位

Abstract

Finger-tip plethysmogram and blood pressure were measured in 15 parturient women during delivery, 4 times during the first stage, 3 times during the second stage and 10 times during the third stage. Pulse-wave shape, pulse-wave height, blood pressure and heart rate were compared between supine position and half-sitting position. In the supine, pulse-wave height decreased gradually after the onset of labor pains, showing the lowest value of 2.3±0.2 mV/V at the end of bearing down labor. During the interval of the pain, pulse-wave height was always higher than that of labor pain. At the middle phase of the first stage when cervical dilatation was 6cm, pulse-wave height exhibited a relatively high value of 9.4±1.3 mV/V. In the half-sitting position, however, there was no remarkable variation in pulse-wave height. At 60 minutes after delivery of the placenta the pulse-wave height was 4.8±1.2 mV/V, and it also remained unchanged for the next 1 hour. In the second stage, the heart rate increased to twice that at the beginning of the first stage in supine position, while the increase remained only 25% in half-sitting position. After the delivery of the placenta, the heart rate decreased remarkably and returned to the control value by 2 hours after delivery. These data indicate that the cardiac load during labor was smaller in half-sitting position than in supine position. In conclusion, the delivery in half-sitting position is recommended.