2. FLUID AND ELECTROLYTES A Practical Bedside Approach VICENTE V. TANSECO, JR., MD,FPCP, FPSN

3. INDICATIONS FOR IV INSERTION To correct Fluid and Electrolyte imbalance To provide calories To keep a vein open as a vehicle for medications/nutrition To anticipate Fluid & Electrolyte imbalance or IV medications

4. F & E PARAMETERS SALINE BALANCE WATER BALANCE POTASSIUM BALANCE HYDROGEN ION BALANCE

5. BASIC F&E PRINCIPLES 60 % of BW is H2O The major fluid compartments 1. ICF 2. ECF a. Plasma - b. Int. FC - 65 % BW 55 % BW 70 % BW 80 % BW 20 % BW 5 % BW 15 % BW - thin - obese - infants

6. FLUID COMPARTMENTS STOMACH INTESTINES BLOOD PLASMA LUNGSKIDNEYS INTERSTITIAL FLUID INTRACELLULAR FLUID SKIN 5 % BODY WT. 4 L 15 % BODY WT. 11 L 40 % BODY WT.30 L

7. ELECTROLYTE COMPOSITION BLOOD PLASMA INTERSTITIAL FLUID INTRACELLULAR FLUID EXTRACELLULAR FLUID Mg++ Ca++ K+ Na+ HCO3 Na+ Cl protein Org. acid SO4 K+ Ca++ Mg++ AG K+ Mg ++ HCO3 HPO4= SO4= Protein HCO3

8. BASIC F&E PRINCIPLES Na+ is the major cation in the ECF K+ is the major cation in the ICF 98-99% only 1-2 % is extracellular All Fluid compartments are separated by a semi-permeable membrane Water passes through the semi-permeable membranes but not solutes to maintain equal osmolality in all compartments

9. BASIC F & E PRINCIPLES Semi-permeable membrane ECFICF Na+ Na+ K+ Na+ H2O H2O Na+ K+ H2O H2O Na+ Na+ K+ H2O Na+ H2O Na+ K+ H2O H2O K+ Na+ K+ H2O K+ Na+ H2O K+ H2O K+ H2O

10. BASIC F&E PRINCIPLES ICFECF Volume increase Addition of Na+ K+ H2O Na+ H2O Na+ Na+ H2O K+ Na+ Na+ H2O H2O K+ Na+ K+ K+ H2O K+ H2O K+ Na+ H2O K+ Na+

11. BASIC F&E PRINCIPLES ICFECF Volume increase - negligible Addition of H2O Osmolality Na+ H2O H2O Na+ Na+ K+ H2O Na+ K+ Na+ Na+ H2O H2O K+ Na+ K+ H2O K+ Na+ K+ H2O K+ H2O

12. WATER BALANCE WATER DEFICIT OSMOLALITY OSMORECEPTORS HYPOTHALAMUSPITUITARY THIRST CENTER ANTIDIURETIC HORMONE COLLECTING TUBULE WATER REABSORPTION WATER INTAKE FEEDBACK

13. REMEMBER ! TALK OF SALINE THINK OF VOLUME TALK OF WATER THINK OF OSMOLALITY

14. SALINE BALANCE

15. SALINE BALANCE ASSESSMENT: HistoryPE 1. ECF Volume: -Orthostatic BP -CVP -Urine Output -Urine Sp. Gr. -Hct. (3 x Hb = Hct.) Blood Volume 2. Interstitial volume -skin turgor -edema -crackles in the lungs -mucosal dryness SALINE VOLUME

16. ESTIMATION OF SALINE DEFICIT WT LOSS SALINE CLINICAL REPLACEMENT PRESENTATION 5 % 50 CC/Kg BW weak, ambulatory, good mental status 10 % 100 CC/Kg BW weaker, non-ambulatory, slow mental status 15 % 150 CC/Kg BW Obtunded, stuporous, Coma, seizures 20 % 200 CC/Kg BW Not compatible with life

17. A SIMPLE ONE ! 1 Kg change in Body weight 1 L change in isotonic saline or sodium balance

18. CORRECTION OF SALINE IMBALANCE MAKE THE DIAGNOSIS COMPUTE FOR DEFICIT OR EXCESS CORRECT 50 % OF EXCESS OR DEFICIT

19. WATER BALANCE

20. WATER BALANCEASSESSMENT: WATEROSMOLALITY History - Thirst PE - CNS Manifestation Laboratory Osmolality Serum Sodium Osmolality=2(Na+) + BUN/2.8 + GLUCOSE/18 Osmolality=2(Na+) n.v. = 280-295 mOsm/L

21. ESTIMATION OF WATER IMBALANCE H20 Deficit (L): =0.5(BW) (Na+/140)-1 100 mg% increase in Blood sugar, add 3 mEq to the serum Na+ 3 mEq change in Na+ =1L change in H2O 1 mEq dec in Na+ for every 4.6 g/l Inc in Lipids

22. CORRECTION OF WATER IMBALANCE MAKE THE DIAGNOSIS COMPUTE FOR WATER EXCESS OR DEFICIT CORRECT 50 % OF COMPUTED EXCESS OR DEFICIT

23. POTASSIUM BALANCE

24. RENAL HANDLING OF K+ K+ IS FREELY FILTERED 90 % IS REABSORBED FROM PROXIMAL TUBULE SECRETION FROM THE DCT AND CT IS THE PRIMARY MODULATOR OF K+ EXCRETION

25. FACTORS AFFECTING K+ EXCRETION ALDOSTERONE Na + DELIVERY TO DISTAL TUBULES H + EXCRETION: - ALKALOSIS ---- K + EXCRETION - ACIDOSIS ----- K + EXCRETION URINE FLOW DIURETICS

26. MORE ABOUT K+ 98 % OF K+ IS INTRACELLULAR SERUM K + CONCENTRATION GENERALLY REFLECTS TOTAL BODY K+ SERUM K + IS AFFECTED BY THE SERUM pH

27. POTASSIUM BALANCE Acidosis K+ is high Alkalosis K + is low H+ ECF ICF H+ K+ H+ H+ K+ K+ H+ H+ K+ K+ K+ H+ H+ K+ H+ K+ K+ H+ H+

28. EFFECT OF pH CHANGE FOR EVERY 0.1 pH CHANGE 15 % CHANGE IN SERUM K + LEVEL

29. POTASSIUM ASSESSMENT: History Physical examination Laboratory: – Serum Potassium level (n.v.= 3.5- 4.5) – EKG: – H+; pH

30. POTASSIUM DEPLETION Muscle weakness, fatigue due to hyperpolarization of cell membranes potential of cells & nerves Low serum K+ (< 3.8 mEq/L) EKG changes: flat inverted T waves, prolonged QT interval, prominent U waves

31. ESTIMATION OF K + DEFICIT A drop of K+ from 4 to 3 100-200 mEq deficit Below 3 mEq/L 1 mEq/L drop in K + 200-400 mEq deficit At 1.5 mEq/L serum K + 400-800 mEq deficit

32. A SIMPLE METHOD For every 1 mEq/L change in serum K+ Equivalent 100-150 mEq/L change in total body K+

33. GUIDE TO K + DEFICIT CORRECTION Oral therapy is desirable For intravenous correction: - If K+ > 2.5 mEq/L and no EKG changes rate than 30 mEq/L of IVF - If K+ < 2 mEq/L w/ EKG changes 40 mEq/HR & conc. Up to 60 mEq/L

34. TREATMENT OF HYPER K+ Calcium Gluconate - 5-10 ml of 10% soln NaHCO3 - 45 mEq iv push (5 min) - 1 L D10W + 90 mEq NaHCO3, 1st 300 cc in 30 min, the rest in 2-3 HRs. - 1 L D10W + 90 mEq NaHCO3, 1st 300 cc in 30 min, the rest in 2-3 HRs. Glucose-Insulin (4 gm:1 Unit) - 300 cc D20W + 15 U RI - 300 cc D20W + 15 U RI - 50 cc D50W + 6 U RI - 50 cc D50W + 6 U RI Cation Exchange Resin: 1 mEq/gm of resin Dialysis

35. CARBONIC ACID DISSOCIATION EQUATION CO2 + H2O H2CO3 H+ + HCO3-

36. HYDROGEN ION BALANCE ANION GAP PROTEINS SODIUM POTASSIUM HCO3 CHLORIDE ANION GAP (Sodium + Potassium)-(Bicarbonate+Chloride)=+10

37. ANION GAP NORMAL EXTRACELLULAR FLUID Mg++ Ca++ K+ Na+ Cl protein Org. acid SO4 HCO3 UREMIA Mg++ Ca++ K+ Na+ Cl protein Org. acid SO4 HCO3 DIABETIC K-A Mg++ Ca++ K+ Na+ Cl protein Org. acid SO4 HCO3 PO4 AG PO4 AG KETONES AG PO4

38. HYDROGEN ION BALANCE NORMAL VALUES -pH : 7.35-7.45 -pCO2: 40 torr -HCO3: 24 mEq/L SIMPLE A/B PROBLEMS – Check for pH: High - ALKALOSIS Low - ACIDOSIS – Check for pCO2: (OR) Opposite- RESPIRATORY (SM) Same- METABOLIC

39. HYDROGEN ION BALANCE MIXED ACID-BASE PROBLEMS: – If pH is NORMAL: No Acid-Base problem Chronic Respiratory Alkalosis Mixed Acid-Base Problem – If Anion Gap is High - METABOLIC ACIDOSIS

40. RULES HCO3 w/ in pCO2 = 1 mEq/l of HCO3 for each 10 Torr in pCO2> 40 HCO3 w/ an acute in pCO2 = 2 mEq/ of HCO3 for each 10 Torr in pCO2 below 40 HCO3 w/ chronic in pCO2 = 4 mEq/L of HCO3 for each 10 Torr in pCO2 above 40

41. HYDROGEN ION BALANCE HistoryPELaboratory – pCO2; pH; HCO3-;

42. HYDROGEN ION BALANCE NORMAL VALUES -pH : 7.35-7.45 -pCO2: 40 torr -HCO3: 24 mEq/L SIMPLE A/B PROBLEMS – Check for pH: High - ALKALOSIS Low - ACIDOSIS – Check for pCO2: (OR) Opposite- RESPIRATORY (SM) Same- METABOLIC

43. RULES HCO3 w/ in pCO2 = 1 mEq/l of HCO3 for each 10 Torr in pCO2> 40 HCO3 w/ an acute in pCO2 = 2 mEq/ of HCO3 for each 10 Torr in pCO2 below 40 HCO3 w/ chronic in pCO2 = 4 mEq/L of HCO3 for each 10 Torr in pCO2 above 40

44. Dx: Acute pneumonia pH: 7.10 pCO2: 70 HCO3: 21 mEq/L pH Acidosis pH Acidosis pCO2 (opposite) RESPIRATORY pCO2 (opposite) RESPIRATORY ACIDOSIS ACIDOSIS DX: RESPIRATORY ACIDOSIS with METABOLIC ACIDOSIS Normal HCO3: 24 expected HCO3 change w/ inc. in pCO2 of 30: +3 expected HCO3 if pt. Has pure RA: 27 actual HCO3 of pt: 21 HCO3 deficit due to Metabolic Acidosis: 6

45. CORRECTION OF H + IMBALANCE Base deficit or excess = change in actual HCO3 X BW X 0.2 2

46. F&E THERAPEUTIC PLAN BASIC ALLOWANCE: LOSS H20 Na+ Cl- K+ urine 1500 50 90 40 S&I 1000 0 0 0 TOTAL 2500 50 90 40 CORRECTIONAL ALLOWANCE: Water Sodium K+ H+ TOTAL

47. ELECTROLYTE CONCENTRATIONS IN DIFFERENT BODY FLUIDS IN Meq/L

48. PRACTICAL PEARLS SALINE BALANCE = VOLUME H2O BALANCE = SERUM SODIUM NEVER USE D5W TO CHALLENGE VOLUME NEVER GIVE K+ TO OLIGURIC PTS. VOMITING - D5NSS DIARRHEA - D5LRS CORRECT ONLY 50 % OF DEFICIT/EXCESS

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