ABSTRACT
Hypovolemic shock in severe pelvic injury, such as open-book pelvic injury is a life-threatening condilion. Increased intrapelvic volume causes loss of temponade effect for bleeding control. Most of the bleeding is confine in the false pelvis and lower abdomen. Therefore, this study is carried out to measure intrapelvic volume from the pelvic floor to the level of the pelvic brim and to the horizontal level of the iliac crest. Ten embalmed cadaver pelvic ring in which the pelvic floor, pubic symphysis and sacroiliac joints were preserved, were dissected. Open-book pelvic ring disruption was created by separation of the pubic symphysis and left sacroiliac joints at 2.5,3,5 and 8 cm separation. Intrapelvic volume was measured at two levels. Level 1 was measured from the pelvic floor to the level of pelvic brim (V1) and level 2 from the pelvic floor to the horizontal level of the iliac crest with reconstruction of anterior lower abdominal wall. V1 and V2 before separation of pubic symphysis were 701.00 ml (SD 69.72) and 1,591.40 ml (Sd215.23) respectively. Percentage of increment of V1 at 2.5,3,5 and 8 cm separation were 3.68 ml (SD 1.29), 6.69 ml (SD 2.08), 9.25 ml (SD 2.63) and 31.28 ml (SD 6.47 respectively and of V2 were 26.08 ml (SD 11.19), 31.36 ml (SD 9.51), 37.06 ml (SD 9.31) and 74.08 ml (SD 18.51) respectively. The increment of V1 at less than 5 cm pelvic ring disruption is minimal when compared with V2 The increment of both V1 and V2 is large when the pelvic ring is disrupted over 5 cm. Obviously, V2 increases much more than V1. The increment of intrapelvic volume in open-book pelvic ring disruption is much greater at the level of the false pelvis and lower abdomen especially when the disruption is more than 5 cm, so that there is loss of the temponade effect of the intrapelvic cavity for the control of bleeding, one of the possible causes of hemodynamic instabiliy.