High yield (hemo)

Question 1

• Non pitting edema: exudate (increase vessel permeability with pus) > 3g
• Pitting edema: transudate (right heart failure) less tha n 3g
• Lymphatic fluid: initially pitting, later not

Answer 1

• Low albumin: nephrotic syndrome, malabsorption, cirrhosis, dec protein intake.

Question 2

• Kerley B lines: usually indicative of interstitial pulmonary edema (CHF), clinically present as dyspnea.
• Kerley A lines: caused by distension of anastomotic channels between peripheral
  and central lymphatics of the lungs (less frequent than B)

Answer 2

• Cirrhosis => dec oncotic prssure (dec albumin synthesis) + inc hydrostatic pressure (portal hypertension) => ascites.
• Pitting edema in the legs can be caused by dec oncotic pressure (cirrhosis) or inc hydrostatic pressure (RHF).
• Lymphedema: post radical mastectomy (#1), Wuchereria Bancrofti, inflammatory carcinoma of the breast, lymphogranuloma venereum (Chlamydia Trachomatis). lymphangiosarcoma is a complication of chronic lymphedema.

Question 3

• Osmolality is mainly determined by Na (doubled, one for Cl), glucose and BUN.
• Diffusion: high => low,
• osmosis: low => high.
• Hyponatremia => osmosis (ICF) => brain edema => mental status abnormality
• Hypernatremia => osmosis (ECF) => brain contract => mental status abnormality
• Glucose is an EC molecule (the IC one is phosphosylated).
• Hyperglycemia => osmosis from ICF to ECF => [Na] dec (dilutional hyponatremia)
• Urea is permeable so it can go through the compartments to establish equilibrium.

Answer 3

• Isotonic loss of fluid (EC loss, no osmotic gradient): hemorrhage, adult diarrhea. Isotonic gain of fluid (EC gain, no osmotic gradient): isotonic saline.
• Hypertonic loss of fluid (ECF => ICF because of hyponatremia): diuretics.
• Hypotonic loss of fluid: sweat, baby diarrhea (you give back hypotonic solution).
• Hypotonic gain of fluid (ECF+ICF expanded): SIADH (treatment: restrict water).

Question 4

• Serum Na less than 120mmol => ALWAYS SIADH (at least on boards…)
• 1st generation oral sulphonylureas (chlorpropamide; insulin secretagogues for DM-II): SIADH as a side effect in 30% of cases.
• Pitting edema (RHF, cirrhosis): gain of both Na and water (but more water). Treatment will be both Na and water restriction, diuretics.
• Glucose or Mannitol in urine => hypertonic loss in the urine.
• Glucose has to be in the solution with Na, because of the gut Na-Glc transporter.
• Normal saline (0.9%) is plasma without the proteins, it stays in the ECF.
• CO dec => renal blood flow dec => peritubular hydrostatic pressure dec => peritubular oncotic
  pressure inc => reabsorption inc (isotonic solution).

Answer 4

• Dry tongue (dehydration) => hyponatremia, skin indentations => hypernatremia
• Normal skin turgor ! normal Na concentrations (except in elderly)
• Diabetes Insipidus CANNOT produce shock (only water loss from ICF, NOT hypovolemic). No dehydration signs (no salt loss). Treatment: 5% dextrose+water
• Tilt test: Lying down (no effective gravity) => normal BP + pulse,
• Sat up (imposing gravity) => BP dec, pulse inc (catecholamine release from BP dec) => sign of volume depletion. Treatment: normal saline (0.45% saline after BP stable)

Question 5

• DKA => hypovolemia => give normal saline (around 6-8 liters until BP stable).
• After BP stabilization, you give what you lose
• Loss of salt => Hypovolemic shock (CO dec, cold skin, TPR inc, MVOC dec, BP dec, pulse inc, LVEDP inc)
• MI => cardiogenic shock (everything like hypovolemic except LVEDP inc)
• E. coli (urinary catheter) => septic shock (CO inc, warm skin, TPR dec, MVOC inc)

Answer 5

• Endotoxins => activate complement ! C3a, C5a (anaphylatoxins) => mast cells => histamine => vasodilation of arterioles.
• Endotoxins => damage endothelieal cells => NO, PGI2 release => vasodilation.

Question 6

• Mixed venous oxygen content can be measured in the right atrium and it is the best test for tissue hypoxia. It is high in septic shock (lots of blood but oxygen cannot be extracted because blood is going to fast), Low in hypovolemic shock.

Answer 6

• Kidney medulla suffers the most from shock (BUN + creatinin inc => sugar inc => ATN => renal tubular casts blocks urine => oliguria). Treatment: inc RBF

Question 7

Sickle cell trait can cause micro infarction in kidney medulla => micro hematuria

Answer 7

Chronic respiratory alkalosis in high altitude is the only case where pH goes completely back to normal

Question 8

Barbiturates, CNS injury => damages resp. center in medulla => resp. acidosis

Answer 8

• Anxiety, pregnancy => respiratory alkalosis => tetany (ionized Ca dec)

signs:
Tourseau sign (compression of the forearm produces spasm in the hand and wrist)
Chvostek's sign (contraction of the muscles of the eye, mouth or nose, elicited by tapping along the course of the facial nerve).

Question 9

• Estrogen and progesterone over stimulate the respiratory system, cause spider angioma on the skin (normal in pregnancy) and AV fistula in the lung

Answer 9

• Endotoxins, Salicylate => respiratory alkalosis+metabolic acidosis. Normal pH.

Question 10

• 6 year child with inspiratory stridor => acute epiglotitis (H. influenza)
• 3 month baby with inspiratory stridor => croup (parainfluenza virus): tracheal obstruction, stipple sign on X-ray.

Answer 10

• ALS, Guillain-Barr, Polio => paralysis of inspiration muscles => resp. acidosis.

Question 11

• COPD => resp. acidosis.

- Restrictive lung disease => resp. alkalosis.

Answer 11

• High altitude: atmospheric pressure decrease => pCO2 inc => pO2 dec => hyperventilation => pCO2 dec => resp alkalosis.
• Caisson’s disease = the bends = decompression sickness: Headache, pain in the arms, legs, joints, and epigastrium, itching of the skin, vertigo, dyspnea, coughing, choking, vomiting, weakness and sometimes paralysis, and severe peripheral circulatory collapse