<prompt> Blood loss during major surgery is best estimated by:Visual assessmentSuction bottlesTransesophageal USG DopplerCardiac output by thermodilution  <response>: Measurement of blood loss during surgery Gravimetric MethodBlood loss during operation is measured by: Weighing the swabs after use and subtracting the dry weight and fluid used volume of blood collected in suction bottles after subtracting irrigating fluid 