Fluid & Electrolyte Emergencies In Critically Ill

1. Fluid & Electrolyte Emergencies In Critically Ill Dr.Patibandla.Sowjanya Dept Of Accident , Emergency & Critical Care Medicine Vinayaka Missions Kirupanandavariyar Medical College

2. Introduction • Total body water (60%) • Two third is intracellular fluid (40%) • One third is extra cellular fluid (20%) - Interstitial fluid (15%) - Intravascular fluid (5%)

3. Fluid shifts INTRACELLULAR 30 LIT 40% EXTRACELLULAR INTERSTITIAL 9 LIT 15% IV 5 LIT 5%

4. Electrolyte Components 142 Na+ 150 K+ Ca2+ Mg2+ Cl- HCO3- HPO42- SO42- Organic acid Protein

6. Osmolarity • Measurement of the total solutes in a water solution per liter. • Osmolarity = [sodiumx2 ]+urea/2.8+glucose/18 • Serum osmolarity is 280-300 mOsm/L • 280-300 mOsmol/L- Isotonic • > 300 mOsmol/L – Hypertonic • < 280 mOsmol/L - Hypotonic

7. Three categories of fluids • Isotonic- Fluid has the same osmolarity as plasma Eg: Normal saline Ringers lactate

8. Hypotonic - Fluid has fewer solutes than plasma Eg : Water, 1/2 N/S (0.45% NaCl)

9. Hypertonic - Fluid has more solutes than plasma Eg:5% Dextrose in Normal Saline (D5 N/S) , 3% saline solution.

10. Isotonic Infusion 2 litres of blood 9 litres 30 litres 3 litres

11. Intravascular Volume increases to 5 liters 9 litres 30 litres 5 litres

12. Hypertonic Infusion 2 litres of colloid 9 litres 30 litres 3 litres

13. Initially it becomes 5 L 9 litres 30 litres 5 litres

14. Hypertonicity of Colloid shifts I/C fluid into I/V 8 litres 29 litres 7 litres

15. If 2 L of Crystalloid infused… 2 litres of 0.9% saline 9 litres 30 litres 3 litres

16. Initially I/V becomes 5L 9 litres 30 litres 5 litres

17. Isotonicity of Crystalloid shifts I/C & I/V volume into interstitial space 29 litres 10.5 litres 4.5 litres

18. Hypotonic Infusion 2 litres of 5%dextrose 9 litres 30 litres 3 litres

19. Hypotonicity Shifts the fluid into the I/C space 9.7 litres 31 litres 3.3 litres

20. Signs of Volume depletion • Postural hypotension • Tachycardia • Absence of JVP • Dry mucosa • Decreased skin turgor • Oliguria

21. Signs of Volume overload • Hypertension • Raised JVP/gallop • Pedal edema • Pulmonary edema • Ascites • Organ failure

22. Basic principles of fluid therapy Abnormal loss: GIT, 3rdspace,Ongoing loss, septic and Hypovolemic shock Replace Insensible water loss + urine Maintain Acid base, electrolyte imbalances Repair

23. The rules of fluid replacement • Replace blood with blood • Replace plasma with colloid • Resuscitate with colloid / crystalloid • Replace ECF depletion with saline • Rehydrate with dextrose

24. Case Scenario • 45 yr old was brought to ER with h/o loose stools & vomiting since 2 days • Drowsy and lethargic with signs of severe dehydration, BP-80/50 , PR-120 What is initial fluid of choice?

25. Isotonic saline / Ringer’s lactate • No dextrose containing fluid initially Why?

26. Critically ill

27. Case Study #1 • HPI: • A 55 year old man is in the Neuro ICU for acute non hemorrhagic stroke. • Hospital course: • Decreasing urine output (< 0.5 ml/kg/hr) over the last 24 hours. What is your differential diagnosis?What diagnostic studies would you order?

28. Case Study #1Differential diagnosis Oliguria 1) Pre-Renal(decreased effective renal blood flow) Diminished intravascular volume, cardiac dysfunction, vasodilatation 2) Post-Renal Outlet obstruction (intrinsic vs. extrinsic), foley catheter occlusion 3) Renal Acute tubular necrosis, acute renal failure, SIADH, ...

29. Case Study #1Laboratory studies Serum studies Sodium 120 mEq/L BUN 4 mg/dL Chloride 98 mEq/L Creatinine 0.4 mg/dL Potassium 3.7 mEq/L Glucose 129 mg/dL Bicarbonate 25 mEq/L Osmolality 260 mosmol/kg Urine studies Specific gravity 1.025 Sodium 58 mEq/L Osmolality 645 mosmol/kg What are the primary abnormalities?

30. Case Study #1Laboratory studies Major abnormalities 1) Hyponatremia 2) Oliguria (inappropriately concentrated urine) What is the most likely explanation for these findings?

31. In Hyponatremia……

32. Case Study #1Syndrome of Inappropriate Antidiuretic Hormone (SIADH) • Variable etiology • Trauma • Infection • Psychosis • Malignancy • Medications • Diabetic ketoacidosis • CNS disorders • Positive pressure ventilation • “Stress”

33. SIADH • By definition, “inappropriate” implies having excluded normal physiologic reasons for release of ADH: • 1) In response to hypertonicity. • 2) In response to life threatening hypotension. • Hyponatremia • Oliguria • Concentrated urine • elevated urine specific gravity • “inappropriately” high urine osmolality in face of hyponatremia • Normal to high urine sodium excretion

34. Case Study #1SIADH • Diagnosis • Critical level of suspicion. • Demonstration of inappropriately concentrated urine in face of hyponatremia •  urine osmolality,  SG,  urine sodium excretion • Be certain to exclude normal physiologic release of ADH

35. Case Study #1SIADH • Treatment • Fluid restriction • Avoid hypotonic fluids • Hypertonic saline / oral sodium chloride • Frusemide.

36. Cerebral Salt wasting Syndrome • Development of excessive natriuresis with hyponatremic dehydration in patients with intracranial disease • Seen in Head injury, Brain tumor, Intracranial Surgery or stroke

37. CSW vs SIADH

38. Case Study #1The saga continues…. Hospital course: Four hours after beginning fluid restriction, you are called because the patient is having a generalized seizure. There is no response to two doses of IV lorazepam and a loading dose of fosphenytoin What is the most likely explanation?

39. Case Study #1The saga continues Seizure 1) Worsening hyponatremia 2) Intracranial event 3) Meningitis 4) Other electrolyte disturbance 5) Medication 6) Hypertension What diagnostic studies would you order?

40. Case Study #1The saga continues Stat labs: Sodium 110 mEq/L What would you do now?

41. Case Study #1Hyponatremic seizure • Treatment • Hypertonic saline (3% NaCl) infusion • To correct sodium to 125 mEq/L, the deficit is equal to • 0.6 X weight[kg] X (125 - measured sodium) • 0.6 X 60 X (125-110) = 54O mEq

42. Newer method • Rate of infusion of 3%NaCl = Na Requirement x 1000 infusate sodium x time • (Desired-Actual Na) x 0.6.body wt x 1000 513 x no of hours • As patient is symptomatic, rate of correction is 1 mEq/hr, • Required rate of infusion of 3% NaCl = 1 x 0.6 x 60 x 1000 513 x 1 = 70 ml/hr • Check sodium after 4 hours and correct accordingly

43. Hyponatremia

44. Case Study # 2 • 60 year old retired engineer presented to ER with history of inability to speak and move all 4 limbs since today morning. Detailed history revealed that he has been on naturopathy diet since 6 months and had developed GTCS 2 days back. He was treated outside for GTCS and following the treatment he is unable to communicate or use his limbs

45. His previous lab reports showed Na is 117 mEq/L and rest of the parameters are within normal Limits • Repeat Sodium in our hospital showed 145 mEq/L • What could be the possibility?

46. Central Pontine Myelinolysis • Develops with • Aggressive treatment of Chronic hyponatremia • Raising Sr.Na >25mEq/L in first 48 hours • Raising Sr.Na to Normal or Above normal in 48 hours

47. CPM • Focal demyelination in the Pons & extrapontine areas. • Causes  Mutism / dysarthria Spastic Quadriplegia Pseudobulbar palsy Seizures Altered Mental Status Coma & Death CPM is irreversible

48. Principles of Hyponatremia Management • Asymptomatic Hyponatremia Use 0.9%NaCl • Symptomatic Hyponatremia Use 3% NaCl • Correct only 12mEq/L defecit only perday • Chronic Hypernatremia with severe symptoms should receive hypertonic saline only to arrest the symptoms and followed by slow correction @ 0.5 mEq/L

49. Hyponatremia Management is Double Edged Sword

50. Case Study #3 HPI: A 5 month-old girl presents with a one day history of irritability and fever. Mother reports three days of “bad” vomiting and diarrhea. Home meds: Paracetamol and ibuprofen for fever PE: BP 70/40, HR 200, R 60, T38.3 C. Irritable, sunken eyes and fontanelle.