Fluid infusion during postpartum hemorrhage: a secondary analysis of the Obstetric Bleeding Study (OBS) Plus...

Optimal fluid resuscitation strategies in PPH are unknown. This planned secondary analysis describes fluid resuscitation during OBS Plus, a study designed to characterise PPH coagulopathy. The hypothesis was that the volume of fluid resuscitation equalled the volume of blood loss. Primary outcome was the ratio of clear fluid infused: blood loss.

Patients recruited into the OBS Plus study with available fluid infusion data and measured blood loss ≥ 1000 mL were included. Clinical management was guided by a PPH care bundle incorporating bedside testing of coagulation. Fluid resuscitation was at the discretion of the clinical team. Infusions commenced 1 h before to 1 h after PPH were analysed.

Between 2017 and 2019, 495 patients with PPH ≥ 1000 mL were recruited. 67/495 (13.5%) were excluded for missing data. Clear fluid infusions were crystalloid, 426/428 (99.5%) and colloid, 39/428 (9.1%). Blood product transfusions were red blood cells, 40/428 (9.4%); fresh frozen plasma 3/428 (0.7%); platelets 5/428 (1.1%). Overall median ratio clear fluids: blood loss was 858:1000 mL with blood products contributing to resuscitation volumes in massive PPH (≥ 2500 mL). Fluid volumes ≥ 3500 mL were only infused in massive PPH. No patients required renal replacement therapy or respiratory support for fluid overload.

Inappropriate clear fluid resuscitation may cause fluid overload or renal injury. In this report, no patient required respiratory or renal support and median fluid resuscitation volume was approximately equal to blood loss. The incidence of coagulopathy in OBS Plus should be interpreted in this context.