James got into a car accident. When the ambulance arrived, Jameswas sitting on the flood next to his car with blood covering him.His car was hit a truck who came wrong way and hit face-to-face.James looks dazed, and as the paramedics approach he says with amixture of panic and relief, “I am covered with blood!†James isonly semi-lucid as he babbles on about pushing out the broken glassin his car window. The paramedic reports quickly that the patientis bleeding from multiple right-arm cuts and especially deeplaceration on the right upper arm. The paramedic stopped thebleeding and move him quickly to the ambulance. James systolicblood pressure is 80 mm Hg (low), diastolic is not audible (too lowto hear). His heart rate is 122 bpm (very rapid), and skin is paleand clammy, indicating peripheral vasoconstriction (narrowing ofhis blood vessels, particularly in the skin) and circulatoryshock-like signs. On the way to the hospital, a paramedic beginstransfusing normal saline solution (NSS; water with some NaCl,similar to body fluids, given directly into his vein).
Up on their arrival to the hospital, a hematocrit HCT wasordered by Dr. Smith and it is low but normal. Several vials ofJames’s blood are also sent to the lab for blood tests and typing.Two liters of NSS are transfused over the next hour while the EDphysician sutures his deepest, right-upper-arm laceration. Despiteno further bleeding since the paramedics treated him at the scene,James had another HCT tested one hour after the original HCT, dropsto below normal. Dr. Smith didn’t order a blood transfusion though.Aside from his present health problem, James is otherwise healthy.He is admitted to the hospital for overnight observation.
Hematocrit is the percentage of total bloodvolume that is comprised of RBCs. Calculate James HCT if PCV forthe RBCs is 1.25ml and plasma volume is 3.75 ml
