Presentation on theme: "INTERACTIVE CASE DISCUSSION"— Presentation transcript:
1 INTERACTIVE CASE DISCUSSION Fluid and Electrolyte DisordersPart I
2 Introduction to Fluids and Electrolytes Fluid & Electrolyte Status AssessmentSodium (Na) balancePotassium (K) balanceWater balanceOther ions: Ca, Mg, Phosphate, etc.
3 Introduction to Fluids and Electrolytes Fluid & Electrolyte Status Assessment“Hypo” – deficit“Hyper” – excess“Eu” or “Normo” - normal; adequate
4 Introduction to Fluids and Electrolytes Assessment of Potassium (K) BalanceMeasuring tool: serum KK = meq/LHypokalemia: < 3.5 meq/LNormokalemia: 3.5 – 5meq/LHyperkalemia: > 5meq/L
5 Introduction to Fluids and Electrolytes Assessment of Water BalanceMeasuring tool: serum NaHypernatremia ( >145 meq/L): water deficitNormonatremia ( meq/L): normal water balanceHyponatremia ( <135 meq/L): water excess
6 Introduction to Fluids and Electrolytes Assessment of Sodium (Na) BalanceMeasuring tool: Physical examination of the patient’s volume statusHypervolemia: Na excess; BP, JVP, edema, ascites, effusion etc.Normovolemia: normal Na balance; normal BP, JVP = 8-12; good skin turgorHypovolemia: Na deficit; BP, JVP, dry mucosa, poor skin turgor etc.
7 Introduction to Fluids and Electrolytes REMEMBER !Serum K = K balanceSerum Na Na balanceSerum Na = Water balanceVolume status = Na balance
8 Introduction to Fluids and Electrolytes Sample Question: A 50 year old male with chronic renal failure has a serum K of 6 meq/L. What is his K status?
9 Introduction to Fluids and Electrolytes Answer:Normal serum K = meq/LSerum K = 6meq/L ( > 5 meq/L)HyperkalemiaK excess
10 Fluids and Electrolytes Part I CASE #1: A 45 year old Japanese tourist collapsed in a shopping mall and was brought to the ER.90/60, HR = 110/minJVP = 4, proximal muscle weaknessLabs: Na = 140, Cl = 110, HCO3 = 16, K = 2.
11 Fluids and Electrolytes Part I Question #1: How will you approach the problem of hypokalemia?
12 HYPOKALEMIA Urinary K excretion <15 mmol/d > 15mmol/d Metabolic acidosisMetabolic alkalosisLower GI K lossRemote diuretic useRemote vomitingK loss via sweatingSinger, 2001
13 HYPOKALEMIA Urine K excretion > 15 mmol/d TTKG > 4 TTKG < 2 Na wasting nephropathyOsmotic diuresisDiureticSinger, 2001
15 Fluids and Electrolytes Part I Question #2: What test will you order next in order to work-up the cause of the hypokalemia?
16 Fluids and Electrolytes Part I Answer #2: 24-hour urine collection to measure 24-hour urinary K excretion.
17 Fluids and Electrolytes Part I Question #3: The 24-hour urinary K excretion rate is 10 mmol/day. Which of the following is the most likely cause of hypokalemia?Barrter’s syndromeDiarrheaHypomagnesemiaLiddle’s syndrome
18 Fluids and Electrolytes Part I Answer #3: DiarrheaThe 24-hour urine K excretion is less than 15 mmol/day.Rest of the choices are renal K-wasting states wherein the 24-hour urine K excretion should be > 15mmol/d.The patient later admitted thru an interpreter that he ate fishballs from a sidewalk vendor 2 days ago and has been having diarrhea since then.
19 Fluids and Electrolytes Part I Case # 4: 38 y/o male alcoholic with cirrhosis. Admitted bec. of anorexia and cachexia. He is not on any medications.BP = 90/60, HR = 105/minABGs: pH= 7.42, pCO2 = 35, HCO3 = 22Creatinine = 0.7 mg/dl (normal)Urea = 8 mg/dl ()K = 6 meq/L ()
20 Fluids and Electrolytes Part I Question #4:How will you approach the problem of hyperkalemia in this patient?
21 HYPERKALEMIA Exclude pseudohyperkalemia Exclude transcellular K shift Exclude oliguric renal failureStop NSAIDs and ACE-inhibitorsAssess K excretionSinger, 2001
24 Fluids and Electrolytes Part I Question #5: What is the next test to order in order to work-up the cause of this patient’s hyperkalemia?
25 Fluids and Electrolytes Part I Answer #5: Compute for the Transtubular K Gradient (TTKG).TTKG = Uk/Pk Uosm/PosmUk = Urine KPk = Plasma KUosm = Urine osmolalityPosm = Plasma osmolality
26 Fluids and Electrolytes Part I TTKG (Transtubular K Gradient):In hyperkalemia:< 5, diminished aldosterone effect 10, normal aldosterone effect,non-renal hyperkalemia
27 Fluids and Electrolytes Part I Question #6: The urine and plasma values are as follows:Pk = 6 meq/LUk = 54 meq/LPosm = 280 mmosm/kgUosm = 260 mmosm/kgCompute for the TTKG.
28 Fluids and Electrolytes Part I Answer #6: TTKG = 10TTKG = Uk/Pk Posm/Uosm= 54/6 280/260= 9/0.9= 10
29 Fluids and Electrolytes Part I Question #7: What is the most likely cause of the patient’s hyperkalemia?HypoaldosteronismK - sparing diuretics (Spironolactone)Low protein intakeRenal tubular acidosis (RTA)
30 Fluids and Electrolytes Part I Answer # 7: Low protein intakeTTKG 10 means normal aldosterone effect (not hypoaldosteronism)In the rest of the choices, the TTKG should be < 5.Patient is likely to have a low food intake (history of anorexia, low serum urea) due to his alcoholism.