Chpt. 29-Alterations of erythrocyte function Flashcards
Polycythemias
Too many cells
Anemias
- Too few cells
- Reduction in total # of erythrocytes in circulating blood or in the quality or quantity of hemoglobin
- Acute or chronic blood loss, impaired erythrocyte production, increased erythrocyte destruction or combo of all the above
Cytic
-Refers to the size
Macrocytic
Large cell
Microcytic
Small cell
Normocytic
Normal cell
Hemoglobin content
ends in chromic
Clinical manifestations of anemia
- Reduced O2 carrying capacity (hypoxia)
- Syncope, angina, compensatory tachycardia, organ dysfunction
- Classic signs: fatigue, weakness, dyspnea, elevated HR, and pallor
- Asymptomatic anemia: may only be seen with exertion and develops gradually.
Treatment of anemias
- Transfusions, dietary correction, administration of supplemental vitamins or iron
- Correcting underlying cause
Other body system dysfunctions of anemia
- CV: Increased preload, HR, and SV, with reduced afterload
- Respiratory: Dyspnea
- Nervous system: Myelin degeneration
- GI: Pain, N/V, anorexia
Cardiovascular function and anemia
- Blood will dilute & flow faster. Increased CO for better O2 delivery.
- Hemorrhage: decreases # of RBC’s which causes decreased blood volume-fluid from interstitum move to intravascular space to expand plasma volume
- Systemic arterial dilation which causes decreases VR and afterload (blood out of the heart)
- Increased HR activated the SNS-need to intervene before HF
Respiratory function and anemia
- increased RR to increase available O2.
- When interventions fail you’ll see dyspnea, palpitations, dizziness, fatigue. May only see w/ exercise but as anemia progresses, you’ll see symptoms at rest
Nervous system and anemia
-Vitamin B12 deficient will see loss of fibers of spinal cord-causing parasthesias, gait disturbance, and weakness
Acute onset of anemia
-Blood is diverted from vital organs (esp kidneys) and starts renin-angiotensin response system to increase water and Na in the blood to increase volume
Macrocytic-Normochromic Anemia
- Also termed megaloblastic anemia
- RBC’s are large
- DNA synthesis is defective (due to deficiencies in B12 and folate)
- Labs: LDH and indirect bilil LDH for cell breaksdown-indirect bili for breakdown of heme.
Pernicious Anemia (Macrocytic-normochromic anemia)
- Most common marcrocytic anemia
- Caused by B12 defiency
- Lacks intrinsic factor from gastric parietal cells (required for B12 absorption)
- Congenital or autoimmune
- Conditions that increase the risk of PA are gastrectomy, HPylori, PPI
Autoimmune PA
-Associated with chronic thyroiditis, DM1, Addisons, primary hypoparathyroidism, and Graves
Environmental factors that contribute to PA
-ETOH, tea consumption, smoking
PA manifestations
- Weakness, fatigue
- Parathesias of feet or fingers, difficulty walking
- loss of appetite, abdominal pains, weight loss
- sore tongue that’s smooth and beefy red, secondary to atrophic glossitis
- lemon yellow (sallow) skin as result of a combo of pallor and icterus
- neuro symptoms from nerve demylenation-not reversible
PA Eval
- methylmalonic acid and homocysteine levels are elevated early on
- gastric biopsy
- Blood tests, serologic test, symptoms, schilling test, B12 absorption, B12 present in urine