Blood everywhere a case study in blood

CASE STUDY #2 CARDIO.

Maggie Silvers is a 48 year-old-woman who was involved in a car accident resulting in a large amount of blood loss. She is transported, via ambulance, to the hospital for treatment. In transport, the paramedics obtain vitals (BP 80, diastolic inaudible, HR 122bpm, skin is pale and clammy). Recognizing these as signs of circulatory shock, Maggie is given NSS. After arriving to the hospital, a fast hematocrit is drawn, and results show a low/normal HCT. Further lab work is performed including blood type and cross. Over the next hour, 2 additional liters of NSS are transfused, the attending physician treats Maggie’s injuries, and another HCT is drawn; this one showing a drop below normal. Maggie is admitted to the hospital for overnight observation. When Maggie arrived at the hospital, she presented with signs of cardiocirculatory hypovolemic shock, due to the excessive amount of blood and fluid loss. Due to the importance of blood in circulating oxygen to all areas of the body, this decrease in blood volume can be life threatening if not treated. A patient experiencing shock of this variety may present with low blood pressure due to decreased blood volume and inadequate pumping of the heart resulting in decreased cardiac output, rapid heart rate as the heart beats faster to circulate blood, and cool/clammy skin due to lack of blood/oxygen moving through blood vessels (Procter, 2018). Without proper function of the heart and blood flow, the rest of the body cannot function properly either. In order to fully determine the extent of Maggie’s injuries, the hospital would need to perform lab work, to include an HCT (hematocrit) draw. Normal range for an adult female HCT is between 38-46% (other sources claim 34.9-44.5%). The fast hematocrit revealed that Maggie’s HCT was low, but normal with red blood cell volume at 7.1mm and plasma volume at 12.9mm. HCT is calculated as follows: HCT = Volume of red blood cells / (Volume of red blood cells + volume of plasma) x 100 HCT = 7.1 mm / (7.1mm + 12.9 mm) /100 HCT = 0.355 / 100 HCT = 35.5 % After receiving two liters of normal saline, Maggie’s HCT dropped to a below normal range: Red blood cell volume was 1.45 mm and plasma volume was 3.55 mm, resulting in a hematocrit of 29%. Despite no further blood loss, this change is most likely a result of the normal saline (NSS) that was administered. While NSS increases blood volume and plasma volume, it does not restore RBC count; the blood is merely “diluted” in a sense to restore flow. If Maggie were to receive a blood transfusion, the RBC count would also increase rapidly, but due to risk of complications with transfusions they are often reserved for emergency situations. NSS is, instead, used to temporarily restore blood volume levels in order to improve blood pressure and ensure adequate flow to the flow. Blood transfusions, while they can save lives in emergency or otherwise indicated situations, also come with multiple risks. The protocol for use is often extensive and involves cross matching the patient with donor blood, obtainment of blood, and consistent observation to ensure that the recipient doesn’t present with any transfusion reactions/complications. The body is capable of restoring itself through negative feedback systems if time allows. For that reason, many doctors are reluctant to push a transfusion unless absolutely necessary. As mentioned, the negative feedback systems within the body are capable of restoring homeostatic balance. When the body experiences a loss of red blood cells, the HCT level drops. Red blood cells are important for delivering oxygen (hemoglobin) throughout the body, so when they are lost, the body experiences hypoxia (oxygen deficiency) at a cellular level. Hypoxia stimulates erythropoiesis (red blood cell formation) in order to restore oxygen delivering capability to the body (Tortora & Derrickson, 2016). As new red blood cells are produced, the HCT level increases, increasing hemoglobin levels and restoring the body to equilibrium. The link between HCT levels and hemoglobin levels make the obtainment of hemoglobin measurement levels an alternative for physicians to get an understanding of oxygen carrying capacity within the body. This physiological mechanism within the body is why when Maggie returned for suture removal a week later, she had improved without having needed a transfusion.

References:

Procter, L. (2018, March). Shock; Heart and blood vessel disorders. Retrieved from https://www.merckmanuals.com/home/heart-and-blood-vessel-disorders/low-blood-pressure-and-shock/shock

Tortora, G. J., & Derrickson, B. (2016). Principles of anatomy & physiology (15th ed., Vol. 1). Hoboken, NJ: John Wiley & Sons.