Precise Estimation of Postpartum Haemorrhage: Difficulties and Importance

Abstract

A method of accurately measuring blood loss is outlined. Blood is extracted in a washing-machine and measured spectrometrically as oxyhaemoglobin. The bleeding that occurred after 57 vaginal deliveries was measured. When this measured amount was compared with the estimate recorded at the time of delivery the estimate was reasonably correct for small losses. However, when the recorded loss exceeded 300 ml. underestimation was invariable, anJ as the loss became greater so did the amount of undercstimation. On the basis of these measurements it is calculated that in over 20%/ of vaginal deliveries the blood loss exceeds 500 ml. A systolic blood pressure below 100 mmn. Hg and a pulse rate above 100 beats per minute are late signs of depleted blood volume and indicate commencing failure of the compensatory mechanisms. © 1967, British Medical Journal Publishing Group. All rights reserved.