PATHO FINAL EXAM REVIEW EXAM 1 Causes of Disease - Idiopathic - Arises spontaneously and cause is unknown Iatrogenic - Caused by medical examination or treatment. Predisposing factors Prophylaxis - Measures we take to try to prevent disease from happening - Ex. Vaccines; baby aspirin every day Adults - 60% water Infants - 70% water Dehydration - v Skin Turgor - v saliva, dry nose + lips - Sunken eyes - Sunken fontanelles (infant) - v BP, weak pulse, ^ HR - ^ hematocrit - Lethargy - Kidneys - v urine output Compensation: THIRD-SPACING - fluid shifts from blood to body cavity/tissue (^OP+cap perm) Sodium (135-145) - Elderly have TOO MUCH usually Moves fluid between IVF + IC - Hyponatremia Loss of fluid into CELLS Causes - ^ Cell size - Fluid loss - diuretics + low salt diets - Hormonal imbalances - Excessive water intake Effects - fatigue - muscle cramps - abdominal pain - v OP - cerebral edema (^ICF in brain) - v BP - Hypernatremia Loss of fluid due to EDEMA Causes - v cell size - v ADH + aldosterone - watery diarrhea - prolonged periods of rapid respiration - ingestion of large amounts of Na+ Effects S kin flushed A gitation L ow grade fever T hirst Chloride - Goes with Na+ Bicarb lvls can shift in response to acid base imbalances - Hypochloremia Alkalosis vomiting - Hyperchloremia Excessive NaCl intake Potassium (3.5-5) - Cation in ICF Influence acid-base Hypokalemia Causes - excessive diarrhea - diuretics - aldosterone/ glucocorticoids (cushing) Hyperkalemia Effects S skeletal muscle weakening U wave on EKG C onstipation / ilias T oxic effects of digoxin I rregular / weak pulse O rthostatic hypotention N umbness Causes - Renal Failure - K+ sparing drugs (Spirlacone) - K+ in ICF leaking into ECF - severe acidosis Effects - cardiac dysrythmias - muscle weakness - fatigue, nausea, parestesia - impares neuromuscular activity Calcium - Vit D needed for Ca+ absorption Strengthens bones + teeth Blood clotting Hypocalcemia Causes - hypoparathyroidism - ^ serum pH - Renal failure - Lack of Vit D Effects - ^ permeability of nerve membranes - muscle twitching - tetany - weak heart contractions Hypercalcemia Causes H yperparathyroidism A ntacids (tums) M malignant tumors * Milk-alkali syndrome Effects - depressed neuromuscular activity - muscle weakness, loss of muscle tone - anorexia, nausea - v urination - stronger cardiac contractions (dysrhythmias) Phosphate - Inverse relationship w/ Ca+ Hypophosphatemia Causes - Metabolism - Diarrhea - Excessive antacids Hyperphosphatemia Effects - bone pain - stiff joints - v appetite - weakness/fatigue Causes - Renal failure Effects - anxiety - bone pain - irregular breathing - numbness Magnesium - Regulates neuromuscular function Regulates blood sugar lvls Hypomagnesemia S eizures T etany A norexia + Arrhythmias R apid HR V omiting E motions D ecreased DTR Normal pH - 7.35-7.45 Normal CO2 - 35-4resp5 Hypermagnesemia R eflex loss E KG changes (bradycardia + v BP) N ausea / vomiting A ppears flushed L ethargy Normal Bicarb - 22-26 Respiratory Acidosis - Caused by hypoventilation, excessive alcohol, + lung issues (Anything that v breathing) - Effects - neurological changes, hyperkalemia, cardiac arrhythmias, ^ urination, v BP, ^HR, v muscle tone, restlessness, papillary edema, warm skin Kidneys compensate → absorb bicarb back into blood + excrete H in urine Respiratory Alkalosis - Caused by hyperventilation, anxiety, anemia, pain, fever, sepsis (Anything that ^ breathing) - Effects - lightheadedness, dizziness/fainting, ^HR, hypokalemia, cardiac arrhythmias Kidneys compensate → retain H + excrete bicarb Metabolic Acidosis - Caused by DKA, malnutrition, lactic acidosis, shock, kidney/GI illness Effects - hyperkalemia, cardiac arrhythmias, ^RR (Kussmaul breathing), headache, v LOC, coma, muscle twitching/burning, flaccid paralysis Lungs compensate → ^RR to get rid of CO2 Metabolic Alkalosis - Caused by vomiting, diuretics Effects - hypokalemia, cardiac arrhythmias, vRR, tetany, tightening of muscles, mental status changes, seizures Lungs compensate → vRR to retain CO2 EXAM 2 Hormones Growth hormone → anterior pituitary → protein synthesis ACTH → anterior pituitary → stimulates adrenal cortex to secrete cortisol TSH → anterior pituitary → stimulates thyroid gland T3 + T4 → thyroid gland → ^ metabolic rate in all cells PTH → parathyroid gland → ^ Ca+ absorption + stimulates bone demineralization Calcitonin → thyroid gland → v release of Ca+ from bone to v Ca+ lvl FSH → anterior pituitary → Women: growth of ovarian follicles + estrogen secretion Men: sperm production LH → anterior pituitary → Women: maturation of ovum + ovulation Men: secretion of testosterone Prolactin → anterior pituitary → breast milk production ADH → posterior pituitary → reabsorption of water by kidneys Aldosterone → adrenal cortex → Na + water reabsorption by kidneys Glucagon → pancreas (alpha cells) → ^ blood glucose lvl Insulin → pancreas (beta cells) → v blood glucose lvl by transporting into cells Epinephrine → adrenal medulla → visceral + cutaneous vasoconstriction (^HR, ^RR) Norepinephrine → adrenal medulla → general vasoconstriction Erythropoietin → kidneys → RBC production ***Negative Feedback System*** Hypoparathyroidism - - Hypocalcemia - Weak pulse - Excitability of nerves Caused by - Tumor - Autoimmune disease - Surgery of gland Hyperparathyroidism - Hypercalcemia - Strong pulse - Osteoporosis - Kidney stones Caused by - Tumor - Renal failure - Paraneoplastic syndrome - Cushing - TOO MUCH corticosteroids ^ risk of infection Addisons - DEFICIT of corticosteroids ^ risk of infection - Weight GAIN (moon face) Thin limbs + hair Striae, bruising Fatigue, weakness, delayed healing - Weight LOSS Fatigue Nausea, anorexia, diarrhea Diabetes Mellitus - Cells are STARVED of glucose Body starts to break down other sources of farbs, protein, and fat to get energy → KETABOLISM → Releases biproducts - ketones - in blood → Diabetic Ketoacidosis → ^ K+ → ^ peeing Type 1 Diabetes - Destruction of beta cells in pancreas Body cannot produce insulin NOT linked to obesity Ppl tend to be thin + loose weight bc of fat breakdown (KETABOLISM) Diabetic Ketoacidosis → Dehydration, rapid deep resp, metabolic acidosis, electrolyte imbalances (cramps, nausea, vomiting, lethargy, weakness) Type 2 Diabetes - Body can produce insulin, it just cannot Not insulin dependant - LIMIT AMOUNT OF GLUCOSE (start patient on pills) LINKED TO OBESITY GENETICS Onset slow and insidious (usually 50+ yrs) Pancreas is overworked over time and grows tired REMEMBER 3 P’S → Polyphasia, Polydipsia, Polyuria *Diagnostic tests – Hemoglobin A1C <7 = well managed.* *REMEMBER: INFECTIONS = ^ GLUCOSE* Hypoglycemia - Insulin shock Glucose deficit Hyperglycemia - Too much glucose in blood Chronic Complications of Diabetes - Vascular problems (PVS) Microangiopathy (changes in microcirculation - clotting of platelets → heart disease) Peripheral neuropathy Infections Cataracts Pregnancy (genetics) Goiter - Enlargement of thyroid gland (both hypo + hyperthyroidism) Hypothyroidism - Iodine defecit Hashimoto’s disease Pale, cool, w/ edema Cold intolerance vHR Weight GAIN Lethargic, slow Hyperthyroidism - Graves Disease Flushed and warm Heat intolerance ^HR Weight LOSS (^ appetite) Exophthalmos Restless, nervous, tremors Skin Disorders Psoriasis → autoimmune - abnormal T-cell activation → chronic inflammation - glucocorticoids - Silvery-gray plaques - Itchy + burning lesions on face, scalp, elbows, knees Scleroderma → collagen deposition - Inflammation + Fibrosis - Hard, shiny, tight, immobile areas MAY CAUSE RENAL FAILURE, intestinal obstruction, + resp failure Pemphigus → autoimmune → antibodies disrupt cohesion between epidermal cells - Mucosa - scaley - Blisters (bullae), skin sheds Urticaria → Hives → Type 1 Hypersensitivity reaction - anaphylaxis Atopic dermatitis → Eczema - Common in infants → rash w/ serous exudate on face, chest, shoulders - Adults → dry, scaly + pruritic on flexor surfaces (elbows) - Chronic inflammation - IgE lvls Contact dermatitis → Type 4 Hypersensitivity reaction (delayed reaction) - Ex. poison ivy, soaps/creams Cellulitis → Bacterial Infection - Erysipelas Red, swollen, painful Red streaks along lymph vessels Furuncles (bolis) → Bacterial Infection → infection of hair follicles - Carbuncles - collections Impetigo → Bacterial Infection - Orange brown lesions on face Acute Necrotizing Fasciitis → Bacterial Infection - Inflammation and tissue necrosis Fever, ^HR, vBP, confusion, organ failure Verrucae → viral Infection → warts - Spreads by shedding of skin surface - Genital warts - HPV types 6+11 Herpes Simplex → HSV-1 - cold sores or fever blisters → HSV-2 - genetal herpes - Complications: Keratitis (eyes), Herpetic whitlow (fingers) Urinary Disorders UTIs Causes → E.coli incontinence, retention Symptoms → dysuria, flank pain, urgency, nocturia hematuria, proteinuria, ^ leukocytes in urine, fever, malaise, nausea Upper UTIs → pyelonephritis - Inflammation of kidneys Purulent exudate blocks urine flow Lower UTIs → cystitis - Inflammation of bladder wall + urethra - Urine cloudy w/ odor → urethritis - Inflammation of urethra Glomerulonephritis → Inflammation of glomeruli - Capillary permeability = leakage of protein + erythrocytes - Congestion + cell proliferation = v GFR , ^BP - Urine dark + cloudy Nephrotic Syndrome → ^ permeability of glomerular capillaries → plasma proteins escape into filtrate - v GFR , vBP - MASSIVE EDEMA - Protein, lipids, casts in urine Urolithiasis → stones - calculi formation - obstruct ureters → anywhere in urinary tract - Hydronephrosis w/ dilation of calyces - Atrophy of renal tissue - Hyperuricemia - Acidic urine Hydronephrosis → Caused by Urolithiasis - Asymptomatic in early stages - Can cause chronic renal failure Nephrosclerosis → vascular disorder → hardening + thickening of arteriole walls + small arteries - ^BP - Ischemia - Can be lesion in kidney Polycystic Kidney → vascular disorder → cysts in kidney - Kidneys ^ in size - Compress + destroy kidney tissue - CT scan or MRI - Can cause chronic renal failure Renal Failure Acute → sudden onset - Severe circulatory shock or HF Chronic → gradual reversal → destruction over long period of time - Bilateral kidney disease Ischemia Blocked urine flow beyond kidneys ^ serum urea, nitrogen creatine Metabolic acidosis hyperkalemia - Chronic kidney disease Stages: v Renal reserve - v GFR - ^ serum creatinine lvls Renal insufficiency - v GFR (20% of normal) - v erythropoiesis - ^BP End-stage - Negligible GFR - 3 As - Azotemia, anemia, acidosis - Dialysis or kidney transplant EXAM 3 Cardiovascular Disorders SA node - pacemaker (sinus rhythm) AV node **Slight delay to allow complete ventricular filling.** Bundle of His Bundle Branches Purkinje Fibers CO - amount of blood that leaves the heart in 1 MINUTE SV - amount of blood that leaves the heart in 1 CONTRACTION HR = CO X SV BP = CO X PR Preload - AMOUNT of blood filling heart before contraction Afterload - PRESSURE/force needed to eject blood Blood Flow of Heart Body → Vena Cava→ Right Atrium → TRICUSPID VALVE (Lubb sound) → Right Ventricle → PULMONIC VALVE (Dubb sound) → Pulmonary Artery → Lungs → Pulmonary Vein → Left Atrium → BICUSPID VALVE (Lubb sound) → Left Ventricle → AORTIC VALVE (Dubb sound) → Body ***Tricuspid before Bicuspid*** ***Aortic before Pulmonic*** Pericarditis Acute - Inflammation of pericardial sac → fluid build up around heart → heart cannot expand fully → decreased heart sounds - Chest pain and friction rub - Pericardial Effusion → jugular vein distention, cardiac tampenod → can lead to HF Chronic - Inflammation is already present and won’t go down - fibrosis scar tissue - formation of adhesions between the pericardial membranes ***Often after open heart surgery.*** ***Potential for atelectasis (collapsed lung)*** Myocardial Infarction - indicator of lack of O2 - Serum enzymes and isoenzymes (+ troponin in bloodstream = tissue damage) ***T WAVE WILL BE HIGH IN EKG*** Common if you have DVT Treatment - Analgesics - Anticoagulants (prevent blood clot from getting bigger) - Thrombolytic agents may be used (takes a long time) Endocarditis - Caused by infection of heart valves - common in people w/ artificial heart valves Acute - sudden onset, high variant + caused by STAPH Subacute - insidious onset, low variant + caused by STREP ***Similar Symptoms as HF → Low grade fever, anorexia, splenomegaly*** Angina Pectoris - Lack of O2 to meet metabolic needs Variant - vasospasm at rest Classic - chest pain when heart does not get enough oxygen w/ activity Unstable - chest pain for very long time - is not relieved by rest → may precede MI ***If chest pain does not cease, take a 3rd Nitroglycerin. If that doesn’t work, call 911.*** Rheumatic Fever - Untreated strep in children (aged 5-15 yrs) v Rheumatic Heart Disease Myocarditis - Inflammation of heart itself Congestive Heart Failure (CHF) - Heart is unable to pump out sufficient blood to meet metabolic demands of the body. Right Sided HF - Right ventricle leads to lungs → BACKS UP ENTIRE SYSTEM Back up effects in body - Edema in feet, legs, + abdomen (acidis) - Distended jugular veins - Weight gain - Hepato + Splenomegaly Left Sided HF - Left ventricle leads to body + COMES FROM LUNGS Back up effects in lungs - Cough - Hemoptysis (blood sputum) + rales → can lead to pneumonia Cardiac Dysrhythmias (Arrhythmias) - caused by hyper or hypokalemia (K+) Cardiac Arrest Cessation of all heart activity - No conduction of impulses - Flat ECG Hypertension - Effects brain, eyes, heart, + kidneys Atherosclerosis - Atheromas or Thrombus forms and causes due to plaques blockage Arteriosclerosis - Hardening of artery wall → loss of elasticity Atrial Stenosis - Thickening and narrowing of valves in aorta Varicose Veins - Irregular, dilated, and tortuous areas of the superficial veins - Leaky valves in veins Caused by long periods of standing Elevate legs + don’t cross legs Thrombophlebitis - Thrombus development in inflamed vein (Ex. IV site) Phlebothrombosis - Thrombus forms spontaneously without prior inflammation; attached loosely Shock Hypovolemic shock - (bleeding out) - Loss of circulating blood volume - Hemorrhage or burns Cardiogenic shock - MI - Inability of heart to maintain cardiac output to circulation Distributive, vasogenic, neurogenic, anaphylactic shock - Changes in peripheral resistance leading to pooling of blood in the periphery - Spinal cord injury, hypoglycemia (insulin shock) Septic - Virulent organisms Blood and Lymph Anemia - O2 deficit - Decreased regeneration of epithelial cells Common symptoms - Fatigue - Pallor - ^ RR + ^HR - Peripheral vasoconstriction - v BP - Digestive tract becomes inflamed and ulcerated → stomatitis - Inflamed and cracked lips - Dysphasia - Hair and skin may show degenerative changes Iron Deficiency Anemia - LOW Iron in blood → v hemoglobin Causes - Low dietary intake OR - Malabsorption - Chronic bleeding (hemorrhoids, cancer, ulcer, etc…) - Heavy periods - Severe liver disease Symptoms - Stomatitis + Glossitis Pernicious Anemia - LOW Vitamin B12 in blood bc of lack of intrinsic factor → v hemoglobin - Very large, immature, nucleated erythrocytes → shorter lifespan Causes - Genetic factor has been implicated - Often accompanies chronic gastritis - May be outcome of gastric surgery ***Vitamin B12 Needed for: RBC formation, neurological function, + DNA synthesis*** Symptoms - Enlarged, red sore, + shiny tongue - Digestive discomfort (nausea/diarrhea) - Tingling limbs (nerves) Aplastic Anemia - Impairment of BONE MARROW Causes - Hep C - Genetic abnormalities → myelodysplastic syndrome Hemolytic Anemia - Excessive destruction of RBCs Causes - Immune reactions (antigen-antibody reactions) - Infections (malaria) - Genetic defects Sickle Cell Anemia - BROKEN hemoglobin changes shape of RBC - Sickle-shaped cells are too large to pass through circulation - Causes multiple infections - Genetic condition - homozygous recessive - 1/10 African Americans have heterozygous trait Symptoms - Hyperbilirubinemia, jaundice, gallstones bc of hemolysis - Splenomegaly - Smaller blood vessels (hands + feet) - CHF - Symptoms do not appear until 12 mo old Thalassemia - LOW hemoglobin Genetic condition - one or more genes for hemoglobin are missing or variant Polycythemia - INCREASED erythrocytes, granulocytes and thrombocytes PRIMARY - Polycythemia vera - Neoplastic, LOW serum erythropoietin, ^ production of erythrocytes SECONDARY - Erythrocytosis - Hypoxia causes ^ RBCs, HIGH serum erythropoietin Symptoms - Distended blood vessels, sluggish blood flow (THINK HEAVY BLOOD = SLUGGISH) - Hepato + Splenomegaly - Dyspnea - Headaches - Hypertrophied heart (enlarged) Visual disturbances Thromboses and infarctions Blood Clotting Disorders - Gum bleeding Epistaxis (nose bleeds) Petechiae (flat red spots on skin + mucous membranes) Purpura and ecchymosis (bruising) ^ bleeding Hemoptysis Hematemesis Blood in feces Anemia LOW BP, ^ HR, rapid pulse Feeling faint + anxious Hemophilia A - DEFICIT of clotting factor VII - Body cannot clot properly INCREASED PTT, aPPT, + COAGULATION TIME BLEEDING TIME AND PT ARE NORMAL Disseminated Intravascular Coagulation - Body clotting TOO MUCH → DEFICIT of clotting factors bc it’s all used up You can bleed out from this Myelodysplastic Syndrome - Inadequate production of cells by BONE MARROW Leukemia Symptoms - Frequent or uncontrolled infections - sepsis, CHF, renal/liver failure, CNS depression - Weight loss + fatigue - Severe + steady BONE PAIN - Headache, visual disturbances, nausea/vomiting - Hepato + Splenomegaly, + enlarged lymph nodes Acute - LOTS OF immature + nonfunctional cells in bone - B lymphocytes - Young CHILDREN Acute Myelogenous (AML) - Granulocytic stem cells + ADULTS Chronic Lymphocytic - LOTS OF mature cells (better prognosis) - B lymphocytes - ADULTS > 50 yrs Chronic Myelogenous (CML) - Granulocytic stem cells + ADULTS 30-50 yrs Diagnostic tests - v RBCs + Platelets, ^ WBCs Treatment - Chemo + biological therapy (interferon to STIMULATE IMMUNE SYSTEM) Lymphomas - lymphocyte PROLIFERATION in lymph nodes Hodgkin lymphoma - ONE lymph node Non-Hodgkin lymphoma - MULTIPLE nodes, non-organized, + widespread metastases - ^ due to HIV INFECTION Symptoms - First → painless enlarged lymph node - Later → Splenomegaly + enlarged nodes - General signs of cancer Treatment - Radiation, Chemo, surgery Multiple Myeloma - - INCREASED production of plasma cells in BONE MARROW - Loss of bone - Severe bone pain OLDER ADULTS Respiratory Disorders Upper Respiratory Tract Infections - Common cold (infectious rhinitis) Viral Secondary bacterial infections may occur (Strep) Purulent exudate → systemic effects like fever Sinusitis (bacterial) Laryngotracheobronchitis (croup) (viral) - children Influenza/Flu (can lead to pneumonia - lower resp. tract) - Sudden acute onset - Achy, fatigue, fever - Type A (most prevalent) - Teens - High mortality rate if acute resp. syndrome (pulmonary edema + pneumonia) - Also Types B + C Lower Respiratory Tract Infections Bronchitis - Necrosis + inflammation in small bronchi and bronchioles - Caused by respiratory syncytial virus (RSV) - ORAL DROPLET TRANSMISSION Symptoms - Wheezing + dyspnea - Cough + rales - Chest retractions - Fever + malaise Pneumonia - Viral, bacterial, or fungal - Changes in interstitial tissue, alveolar septae, or alveoli Symptoms - Fever, chills, + cough Lobar Bronchopneumonia - 1 or 2 lobes - - Strep - - Inflammation of alveolar wall Leakage of cells, fibrin, + fluid into alveoli Inflamed pleura Sudden acute onset RUSTY sputum RALES → absent breath sounds - - Scattered small patches (BOTH LUNGS) Bacteria Inflammation + purulent exudate Insidious onset YELLOW-GREEN sputum DYSPNEA Interstitial Pneumonia (Primary Atypical Pneumonia - PAP) - Scattered small patches - Legionnaires’ disease - Influenza - Interstitial inflammation AROUND alveoli - Necrosis of bronchial epithelium - Variable onset - NO sputum - Unproductive cough, hoarseness, sore throat Tuberculosis - Inflammation + destruction of lung tissue Symptoms - Cough + rusty sputum - ORAL DROPLET TRANSMISSION - Can survive in dried sputum for WEEKS - Destroyed by UV light, heat, alcohol, glutaraldehyde, + formaldehyde Primary/Latent - exposed + infected but asymptomatic + NOT CONTAGIOUS Secondary/Reinfection TB - cell-mediated immunity is impaired bc of stress, malnutrition, HIV,age - CONTAGIOUS Miliary/Extrapulmonary TB - children <5 yrs → weight loss + measles - lesions NOT in lung = NOT CONTAGIOUS Aspiration - Obstructive Lung Disease - foreign material in lungs Inflammation + swelling → resp. Distress syndrome Can lead to pneumonia Symptomes - Coughing + choking w/ dyspnea - Stridor - Wheezing - Nasal flaring, chest retractions, + hypoxia ***HEIMLICH MANEUVER*** Asthma - Bronchial Obstruction - Bronchoconstriction (contraction of smooth muscle) - Coughing + Wheezing - Respiratory Alkalosis - hyperventilation - Respiratory Acidosis - air trapping Extrinsic - acute episodes (TYPE 1 HYPERSENSITIVITY) Intrinsic - onset in early childhood - Thick or sticky mucus build-up or Inflammation Treatment - bronchodilators (v inflammation) or cromolyn sodium (prophylactic med) Chronic Obstructive Pulmonary Disease (COPD) - Irreversible damage to lungs Emphysema - Destruction of alveolar walls and septae + Fibrosis → large, permanently inflated alveolar air spaces - Some infections - Pink Puffer - Barrel-chested - Dyspnea - Prolonged expiration - Hunched over - PURSED LIPS BREATHING - Anorexia + Fatigue - (patient is so tired from breathing that they just lose their appetite) Chronic Bronchitis - Mucus secretion, inflammation/obstruction of bronchi - FIBROSIS OF BRONCHIAL WALL - Frequent infections - Coughing twice for 3 mo or > 2 yrs ***History of Smoking*** - Blue Bloater - Hypoxia, cyanosis, hypercapnia - Cough and rhonchi more severe in MORNING Pulmonary Edema - Fluid in alveoli and interstitial area → Crackles - Cough + Rales - Orthopnea → feel like choking when lying down Pulmonary Embolus - Blood clot or mass obstructs pulmonary artery - 90% come from DVT Symptoms - Later: Hemoptysis (bc of inflammation) + fever - Hypoxia: causes anxiety, restlessness, pallor, ^ HR Atelectasis - Air in pleural cavity Causes partial or full collapse of lung Pneumothorax - Partial (usually lower right lobe) or Full Collapse of lung due to atelectasis Closed - Air enters pleural cavity through internal airways - Asymmetrical chest movements Open - Opening in chest wall (stab wound) - “Sucking wound” - Mediastinal flutter, impairing venous return ***Tension Pneumothorax is most severe → tear in lung surface*** Treatment - Cover open wound - Do not remove protruding objects - If possible tension pneumothorax should be converted to open pneumothorax by removing loose tissue or enlarging opening Pleural Effusion - Excess fluid in pleural cavity → prevents lung from expanding fully Often result of SURGERY Acute Respiratory Distress Syndrome → Ex. COVID-19 - Injury to the alveolar wall and capillary membrane Release of chemical mediators Acute Respiratory Failure - May result from acute or chronic disorders