This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
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? 
Select and explain. 
A. Checking for pallor, B. Volume in suction bottles & increase in weight of swabs, C. Cardiac output by thermodilution method, D. Transesophageal Doppler
B: Volume in suction bottles & increase in weight of swabs
Answer: B: Volume in suction bottles & increase in weight of swabs 
Explanation: 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.