Laboratory Assessment of Iron PDF

118 Laboratory Assessment of Iron DISEASE SERUM IRON TRANSFERRIN TIBC SERUM (µg/dL) SATURATION {%) (µ...

118 Laboratory Assessment of Iron DISEASE SERUM IRON TRANSFERRIN TIBC SERUM (µg/dL) SATURATION {%) (µg/dL) FERRITIN (µg/dL) Normal 65-175 (M) 20-55 250-425 20-250 (M) 50-170 (F) 10-120 (F) Storage Iron Depletion (No Anemia) N N N t Iron Deficiency Anemia t t + t Anemia of Chronic Disease (Inflammation) t t t + Thalassemia Hemochromatosis ,t. + ,t. + t t + Sideroblastic Anemia + + N + Acid-Base Balance METABOLIC ACIDOSIS HENDERSON-HASSELBALCH EQUATION 1. Primary bicarbonate deficit (t HCOj 1. Definition - logarithmic expression of a. Diabetic ketoacidosis ( acid + ionization constant equation of a weak production) acid b. Renal disease ( t J-J+ excretion; decreased readsorption of HCOj) 2. Formula c. Prolonged diarrhea (excessive a. pH = pKa + log [HC0 3-) HC0 3 loss) d. Late salicylate poisoning [H 2C03] 2. Compensatory mechanism s want this ratio to be 20 a. Primarily respiratory 1 ❖ Hyperventilation ❖ t pC02 b. pH p roportional to: b. Some r enal (ilkidney fun ction ❖ log HC03- normal) pC02 ❖ +excretion of JI+ ❖ kidney ❖ Reahsorption of HC03 lungs ❖ metabolic 3. Lah Findings respiratory a. t pH, H CO3, CO2 and pCO2 b. Acid urine SAMPLE COLLECTION AND HANDLING METABOUC ALKALOSIS 1. Anticoagulant - sodium heparinate (heparin) 1. Primary H CO3 excess ( HCOj} + 2. Seen in: 2. Must use anaerobic collection for pH a. NaHCO3 infusion and blood gas studies b. Citrate (anticoagulant in blood transfusions) 3. If blood is exposed to air (bubbles in c. Antacids (contain HCOj) syringe; uncapped tube): d. Vomiting (HCJ loss; prolonged a. CO2 and pCO2 t vomitingjeads to alkalosis due to GI h. pH ♦ loss of FI ) c. pO2 ,t. e. K+ depletion 4. If testing prolonged (> 15 minutes) blood f. Diuretic therapy should be k ept in cracked ice to prevent g. Cushing's Syndrome glycolysis , which leads to: (+ mineralocorticosteroids) a. CO2 and pC02 + 3. Compensatory mechanisms b. pHt a. Primarily respiratory C. pO2 t ❖ Hypoventilation ❖ ,t- retention of CO2  119 b. Some renal - 5. Primary respiratory dysfunction ❖ t excretion of H+ results in change in pCO2 (~eesaw); ❖ +excretion of HCO'j main compensation is HCO3 (metabolic) 4. Lab Findings - ,t. pH, HCO3, CO2 and pCO2 6. Primary metabolic dysfunction results RESPIRATORY ACIDOSIS in change in HCO3_ (swing); main + 1. Primary CO2 excess ( pC02) compensation is pCO2 (respiratory) BASE EXCESS / DEFICIT 2. Seen in: 1. Defined as amount (dose) of acid or a. Emphysema alkali needed to return pH to normal b. Pneumonia c. Rebreathing air (paper hag) 2. Calculated using pH and pCO2 3. Compensatory mechanisms 3. Assess metabolic compon ent of acid- a. Mainly renal - base disorder ❖ ,t. H+ excretion a. Positive value (base excess) = ❖ HCO3reabsorption metabolic alkalosis b. Some respiratory (if defect is not in b. Negative value (base deficit) = the respiratory center) metabolic acidosis 4. Lab findings - t pH and ,t.. HCO3, CO2 and pCO2 Blood Gas Reference Ranges RESPIRATORY ALKALOSIS 1. Primary CO2 deficit (t pC02) PARAMETER DEFINITION "NORMAL" 2. Seen in: pH Negative Log of H+ 7.35-7.45 a. Hyperventilation (blowing off too pCO2 P.:irtiol Pressure or Tension 35-~5 mm Hg much CO?) of CO2 in Blood b. Early salicylate poisoning HCO3 Bicarbonate - Calculated 22-26 mM/L 3. Compensatory mechanisms a. Mainly renal pO2 Ox~gen Tension - Partial 85-1 05 mm Hg ❖ t H+ excretion ressure of Oxygen 4. Lab findings - ,t.. pH and HCO3, t pCO2 and CO 2 EVALUATING ACID-BASE DISORDERS 1. Look at pH; determine if acidosis or alkalosis REMEMBER! Blood Gas 2. Compare pCO2 and HCO3 to 11normals 11 a. pCO.J going opposite to pH = "Normals" respiratory b. HCO3 going same direction as pH = I like my oxygen at 100, metabolic p02 but 90 will do. 3. If pH normal, full compensation occurred 1/2 (90) = 45 4. If main compensatory mechanism nco- 3 kicked in, but pH still out of normal 1/2 (45) ~ 23 (a little >1/2) range, partial compensation has occurred pH 1/3 22.5 ~ 7.4 a little >1/3 120 Factors Affecting Blood Gas Analysis pH pC02 p02 Bubbles in Syringe Sample Sitting MoreThan 30 Minutes (Not on Ice) t + t + t REMEMBER! Factors Affecting Blood Gases Let me introduce the characters who will help you remember blood gases: Phonetia (pH), Carbo (Bicarbonate - HCO3), and Paco (pCO2) Phonetia flies through the air but... Paco falls from the air.. but rises , = after sitting. 1 I' I (Air bubbles in syringe ,i.. pH, prolonged I sitting at roomtemperature t pH) I \ / / / ~~ =------ (Air bubbles in syringe t pC02; prolonged sitting at room temperature ,i.. pC02) 0 2 is simple: Exposure to air(oxygen) causes ♦ in pO2 ; prolonged sitting causes loss of air, at in pO2. Compensatory Mechanisms Resp. Acidosis Renal ♦ HC01 Resp. Alkalosis Renal t Hco~ Metabolic Acidosis Lung t pC02 Metabolic Alkalosis Lung ,t. pC02  121 REMEMBER! Acid-Base Status To determine acid base status (respiratory or metabolic) picture yourself in Rome. You are on a playground with Phonetia (pH), Carbo (HC03), and Paco (pC02)- Phonctia and Paco h op on the seesaw and begin to play. Up and down , up and down. When the pH and pC02 are in opposite R Respiratory directions from "normal," the sta tus is r espiratory (respiratory = opposite). 0 Opposite Phoentia tires of playing with Paco and runs off to join Carbo who i s on a swing. Both go up and both M Metabolic go down, always together. When pH and HC03 are either both ,t. or both t , the status is metabolic (metabolic = equal). E Equal pH > 7.45 = alkalosis pH< 7.35 = acidosis Compensation occurs in respiratory situations when Carbo gets mad at Phonetia for playing with Paco and hops on Paco's side of the seesaw! pH (Plwentia) goes up, pC02 and HCO3 (Paco and Carbo) go down. pH comes down, pC02 and HC03 go up. Compensation occurs in metabolic situations when Paco decides to crash the swinging twosome and hops on with Phonetia and Carbo. Now all go up or all go down. Hey who needs Henderson or Hasselbalch !! ! 122 ACID-BASE PROBLEMS Hemoglobin Derivatives Determine the acid-base status in each of 1. Hemoglobin (Hb) breakdown products the following examples: ind ude porphyrins, bilirubin and 1. urobilinogen pH= 7.24 pC02 = 44 LABORATORY ANALYSIS OF PORPHYRINS AND HC03=18 RELATED COMPOUNDS Answer: Metabolic Acidosis 1. Urines with large amounts of ( uncompensated); Phonetia and Carbo porphyrins sh ow a red or "port wine" are swinging down. pH< 7.35 color 2. 2. Chromatography (HPLC, ion- pH= 7.52 exchange) to separate. All porphyrins pC02 = 44 h ave a characteristic pink fluorescence HC03= 39 (can be quantitated using a UV spectrophotometer or flurometer) Answer: Metabolic Alkalosis ( uncompensated); Phonetia and Carbo 3. Watson-Schwartz test are swinging up. pH> 7.45 a. Porphobilinogen (PBG) will react with Ehrlich's reagent, p-dimethyl- 3. aminobenzaldehyde, to form r ed pH= 7.26 color pC02 = 56 b. Add chloroform to separate PBG HC03= 24 from interfering compounds including urobilinogen (UBG) Answer: Respiratory Acidosis ❖ Color in chloroform top layer= (uncompen sated); Phonetia and Paco UBG and other interfering are on the seesaw. pH< 7.35 compounds ❖ Color in aqueous bottom layer = 4. PBG pH= 7.52 pC02 = 28 LABORATORY ANALYSIS OF BILIRUBIN HC03= 21 1. Diazotization methods Answer: Partially compensated respiratory alkalosis. Phonetia and Paco are seesawing. Carbo joins Paco to compensate. Correlate Porpbyrin 5. Reaults with Disease pH= 7.39 (tiee Bematology cbapwr) pC02 = 25 HC03= 15 a. Classic method ❖ Bilirubin + diazotized sulfanili.c Answer: Completely compensated metabolic acidosis or completely acid ~ azobilirubin (purple) ❖ Total bilirubin (conjugated+ compen sated respiratory alkalosis. For unconjugated) reacts slowly with these situations, look at the pH. If it is diazo reagent on the low side of normal, choose ❖ Conjugated biliruhin (direct) acidosis. If it is on the high side of normal, choose alkalosis. In a like reacts rapidly with diazo reauent manner, completely compensated in water Jendrassik-Grof m:thod metabolic alkalosis cannot be uses caffeine-benzoate as accelerator distinguished from fully compensated c, Direct= conjugated= water soluble respiratory acidosis. The Phonetia, d. Indirect = unconjugated = r elatively Paco and Carbo story will work > 90% of the time in solving acid-base insoluble in water problems.