You are performing explorative laparotomy after a penetrating abdominal injury. The surgery is prolonged and you suspect heavy blood loss. Which of the following will give you the best understnding of the actual blood loss?

Here the Gravimetric method gives the best estimation of blood loss. The weights of the swabs after use are subtracted from the dry weight of the swabs and this is added to the volume of blood collected in the suction bottles and/or drains. Ref: Bailey and Love, 24th Edition, Page 61.