patio exam 2 easier

Anemia

↓ O2-carrying capacity of blood

Polycythemia

Too many RBCs

Microcytic vs macrocytic

Micro = small RBCs (iron deficiency); Macro = large RBCs (B12/folate deficiency)

Hypochromic

Low hemoglobin in RBCs

Hematocrit

% of blood made of RBCs

Reticulocyte count

Shows if marrow is making RBCs; ↑ with bleeding/hemolysis, low with marrow failure

Why anemia causes symptoms

Less O2 delivered to tissues

Main signs of anemia

Fatigue, pallor, cold hands/feet, dyspnea on exertion, tachycardia

Severe acute blood loss anemia

Emergency: ↓ BP, vasoconstriction, ↓ urine output, MI-like symptoms

Body's compensation for anemia

↑ cardiac output, vasodilation to organs, ↑ erythropoietin

Most common anemia

Iron deficiency anemia (IDA)

IDA RBCs

Microcytic + hypochromic

IDA causes

Poor diet, poor absorption, ↑ need (growth, menses, pregnancy), chronic blood loss

Most common cause of IDA in adults

Chronic GI blood loss (e.g., NSAID/aspirin ulcers)

Why infants get IDA

Breast milk has little iron

IDA labs

↓ Hgb, ↓ Hct, ↓ MCV, ↓ ferritin, ↓ serum iron

IDA treatment

Treat the cause + iron supplements

Where is iron absorbed?

Duodenum

Iron storage form

Ferritin

Which iron absorbs better?

Animal (heme) iron

Megaloblastic anemia cause

B12 or folate deficiency

Megaloblastic anemia RBCs

Large (macrocytic), normochromic

Why megaloblastic anemia happens

Impaired DNA synthesis → cells can't divide/mature properly

Pernicious anemia

B12 deficiency from lack of intrinsic factor

Cause of pernicious anemia

Autoimmune attack on stomach lining (gastric atrophy)

Intrinsic factor

Made by stomach parietal cells; needed to absorb B12 in the ileum

B12 deficiency unique symptom

Neurologic: numbness/tingling, unsteady gait

Folate deficiency in pregnancy

Neural tube defects (spina bifida, anencephaly)

B12 treatment

Oral/sublingual/nasal; IM if pernicious anemia

Aplastic anemia

Bone marrow fails → pancytopenia (all blood cells low)

Aplastic anemia causes

Chemo, radiation, drugs, infection, autoimmune, idiopathic

Hemolytic anemia

RBCs destroyed too early

Hemolytic anemia signs

Jaundice, hyperbilirubinemia, enlarged spleen/liver

Hereditary hemolytic anemias

Sickle cell and thalassemia

Sickle cell anemia

Genetic abnormal hemoglobin → crescent-shaped RBCs

Sickle cell: why pain/crisis

Sickled cells block small vessels → ischemia and necrosis

Sickle cell early sign

Swollen hands and feet + fever

Thalassemia

Genetic abnormal hemoglobin → malformed RBCs

Relative polycythemia

Dehydration (↓ plasma volume), not true ↑ RBCs

Primary polycythemia (vera)

Bone marrow neoplasm making too many RBCs (also WBCs, platelets)

Secondary polycythemia

↑ erythropoietin due to chronic low O2

Causes of secondary polycythemia

Lung disease, smoking, heart disease, high altitude, renal tumor

Polycythemia problem

Thick blood → ↑ viscosity → HTN, ischemia, clots

Polycythemia skin sign

Bluish discoloration (lips, nails)

immune thrombocytopenic purpura

Autoimmune: antibodies coat platelets → destroyed in spleen

immune thrombocytopenic purpura main result

Thrombocytopenia (low platelets) → bleeding

immune thrombocytopenic purpura key sign

Petechiae

Other ITP bleeding signs

Nosebleeds, gum bleeding, heavy periods, GI bleeding, hematuria

Acute immune thrombocytopenic purpura

Children 2–6 yrs after a viral infection/live vaccine; resolves

Chronic immune thrombocytopenic purpura

Adult women 20–50; linked to SLE and HIV

immune thrombocytopenic purpura treatment

Corticosteroids; splenectomy

coronary artery disease

Narrowed coronary arteries → ischemia of heart muscle

Most common cause of coronary artery disease

Atherosclerosis

Ischemia vs infarct

Ischemia = low blood supply (reversible); Infarct = tissue death

Angina

Chest pain from ischemia; O2 demand > supply

Stable angina

Predictable pain with exertion, relieved by rest

Unstable angina

New or worsening pain – emergency, can lead to MI

Why angina hurts

Anaerobic metabolism → lactic acid + adenosine build up

Angina/MI pain spread

Neck, jaw, back, left arm

Women's MI symptoms

Dyspnea, dizziness, jaw/epigastric pain

Unstable angina treatment

Oxygen, nitrates, aspirin, angioplasty, morphine

Nitrates do what?

Vasodilate

Aspirin does what?

Prevents platelet clumping (clots)

myocardial infarction

Prolonged ischemia → irreversible heart muscle death

Where myocardial infarction usually happens

Left ventricle and septum

myocardial infarction causes

Coronary blockage (plaque/clot) or ↑ demand (severe HTN, aortic stenosis)

Cardiac enzyme markers

CK-MB and troponin

CK-MB timing

Rises ~4 hrs, peaks 18–24 hrs, gone in 3–4 days

Troponin

Most sensitive MI marker; stays elevated up to 2 weeks

ST-elevation myocardial infarction

Full-thickness (through-wall) MI; ST elevation; worse

NSTEMI

Subendocardial MI; less damage; better prognosis

Most common MI complication

PVCs (premature ventricular contractions)

PVC ECG look

Wide, bizarre QRS; no P wave

Most dangerous post-MI arrhythmia

Ventricular fibrillation

V-fib

Ventricles quiver → no pumping → cardiac arrest

Asystole

No heart contractions

Post-MI heart failure

Damaged ventricle can't pump → pulmonary edema

Mural thrombus after MI

Clot on ventricle wall; can embolize to brain, kidneys, spleen

Cardiac rupture after MI

Blood fills pericardial sac → cardiac tamponade

Cardiac tamponade

Fluid/blood compresses heart so it can't fill

Ventricular aneurysm

Late MI complication: scarred wall bulges out; can rupture

Endocarditis

Infection of heart lining/valves (usually bacterial)

Endocarditis bacteria

Strep viridans and Staph aureus

Endocarditis risk factors

IV drug use, tooth extraction, valve defects

Vegetations

Fibrin + microbe clumps on valves

Septic emboli

Pieces of vegetations that travel and cause infarcts

Endocarditis signs

Fever, chills, weight loss, new murmur

Myocarditis

Inflammation of heart muscle, usually viral

Pericarditis

Inflammation of pericardium; often viral or 2–3 days post-MI

Pericarditis hallmark sign

Friction rub

Pericarditis problem

Fibrin/scarring restricts ventricular filling → ↓ cardiac output

Heart failure

Heart can't pump enough blood for body's needs

Most common cause of HF

Ischemic heart disease

Cause of LVF

Hypertension

Cause of RVF

Chronic lung disease

Cor pulmonale

Right heart failure caused by lung disease

Dilated cardiomyopathy

Big, floppy, weak ventricles; unknown cause

Hypertrophic cardiomyopathy

Genetic thick heart muscle (esp. septum); arrhythmias, sudden death

Left-sided HF backs up into

Lungs (pulmonary edema)