Fluid and electrolyte therapy

A presentation done at the paediatrics department, Lagos State University Teaching Hospital, Ikeja, Lagos State, Nigeria.

1. PRESENTED BY: HAMZAT ZAHEED A. LAYENI ABIMBOLA E. Monday, 14 November 2016 HAMZAT AND LAYENI 1

2. OUTLINES Introduction Basic physiology Normal fluid and electrolyte requirement Dehydration Fluid replacement therapy Osmolality problems Management of osmolality problems Conclusion Monday, 14 November 2016 HAMZAT AND LAYENI 2

3. INTRODUCTION Fluid and electrolyte therapy is an essential component of the care of hospitalized children, and a thorough understanding of the changing requirements of growing children is fundamental in appreciating the many important pharmacokinetic changes that occur from birth to adulthood . While there are many factors that contribute to the fluid and electrolyte needs of children, approaching this therapy in a systematic, organized fashion can help meet ongoing as well as changing needs of the patient Monday, 14 November 2016 HAMZAT AND LAYENI 3

4. BASIC PHYSIOLOGY The body is comprised of solids and water; the proportion of water changes according to age. Total body water (TBW) is divided between the intracellular fluid (ICF) and the extracellular fluid (ECF), separated by cell membrane . At birth, a higher percentage of water is in the ECF, unlike older children and adults where the higher proportion is intracellular. Monday, 14 November 2016 HAMZAT AND LAYENI 4

5. CHANGES IN BODY WEIGHT, BODY SURFACE AREA AND FLUID COMPOSITION WITH AGE PRETERM NEONATE NEONATE 1YEAR 3 YEAR ADULT Weight (kg) 1.5 3 10 15 70 BSA (m2) 0.15 0.2 0.5 0.6 1.7 BSA/weight 0.1 0.07 0.05 0.04 0.02 TBW (%) 80 78 65 60 60 ECF (%) 50 45 25 20 20 ICF (%) 30 35 40 40 40 Monday, 14 November 2016 HAMZAT AND LAYENI 5

6. Despite having a similar osmolality ( 290–320 mosmoles /Kg), the electrolyte content of the ECF and ICF are very different . The ECF contains a high concentration of sodium, bicarbonate and chloride , with a low concentration of potassium, calcium and magnesium . In contrast, the ICF has a high concentration of potassium and magnesium and a low concentration of sodium and bicarbonate. Monday, 14 November 2016 HAMZAT AND LAYENI 6

7. Osmolality : … is a count of the total number of osmotically active particles in a solution and is equal to the sum of the molalities of all the solutes present in that solution . Normal = 290-310 mOsm /Kg Molarity …. is the number of particles of a particular substance in a volume of fluid ( eg mmol /L ) & Molality …. is the number of particles dissolved in a mass weight of fluid ( mmol /kg ) Monday, 14 November 2016 HAMZAT AND LAYENI 7

8. NORMAL FLUID AND ELECTROLYTE REQUIREMENTS Fluid and electrolytes required to replace daily losses and to maintain an overall net balance of zero gained or lost are often referred to as “maintenance” needs. These needs vary from day to day and from individual to individual . In 1957, Holliday and Segar developed an easily remembered formula for calculating caloric requirements of hospitalized children from body weight They also showed that the water requirement in millilitres was equal to the total energy expended. Goals of Maintenance Fluids Monday, 14 November 2016 HAMZAT AND LAYENI 8

9. DAILY FLUID REQUIREMENTS Holliday-Segar Method Holliday-Segar Estimate First 10 kg 100 mL/kg/day 4 mL/kg/hr Second 10 kg 50 mL/kg/day 2 mL/kg/hr Every kg thereafter 20 mL/kg/day 1 mL/kg/hr Monday, 14 November 2016 HAMZAT AND LAYENI 9 Other methods of estimating maintenance fluid requirements exist, including : Body surface area (BSA) Basal calorie requirements.

10. FREQUENTLY USED MAINTENANCE FLUID Age (days) / Weight ( kgs ) Requirements: mL/kg/day Hourly: mLkg / hr Type of fluid 1 50-60 2-3 10 %dextrose 2 60-70 3-4 10%dextrose in 0.22% saline 3 70-80 4-6 10%dextrose in 0.22% saline 4 80-100 6-8 5-10% dextrose in 0.22% saline 0-10kgs 100 4 mL/kg/hr 5% dextrose in 0.45% saline 10-20kgs 1000+50mL/kg 40 mL + 2 mL/kg/hr 5% dextrose in 0.45% saline >20kgs 1500+20mL/kg 60 mL + 1 mL/kg/hr 5% dextrose in 0.45% saline Monday, 14 November 2016 HAMZAT AND LAYENI 10 CONDITION REQUIRING OVER 100% OF MAINTENANCE FLUID

11. DAILY ELECTROLYTE REQUIREMENTS Estimates for daily electrolytes can be based on metabolic demands or, by extension, on daily water needs : • Sodium 2 - 3 mEq /100ml H2O /day • Potassium 1 - 2 mEq /100ml H2O / day • Chloride 2 - 3 mEq /100ml H2O / day Monday, 14 November 2016 HAMZAT AND LAYENI 11

12. IMPORTANT CAVEATS ABOUT DAILY FLUID AND ELECTROLYTE MANAGEMENT Equations for fluid and electrolyte “maintenance” are based on a series of ASSUMPTIONS, including: • Average insensible losses • Average energy expenditure and metabolism • Average urinary losses • No additional losses from other sites • Normal renal function Monday, 14 November 2016 HAMZAT AND LAYENI 12

13. FLUID IMBALANCE Fluid imbalance results when maintenance of fluid input and output within the body is impaired or when homeostatic regulatory mechanisms in the body begin to malfunction usually as a result of an underlying pathology Fluid imbalance can either be dehydration or overhydration Monday, 14 November 2016 HAMZAT AND LAYENI 13

14. DEHYDRATION Dehydration is defined as the excessive loss of body fluid with an accompanying disruption of metabolic processes or a state of fluid deficit in the body It can be either NO, SOME or SEVERE based on how much of the body’s fluid is lost or not replenished. When dehydration is severe enough, it can lead to shock . Monday, 14 November 2016 HAMZAT AND LAYENI 14

15. CLASSIFICATION BASED ON: Fluid volume depletion Plasma tonicity [osmolality ] Sodium deficit. FORMS OF DEHYDRATION Isotonic/Isonatreamic dehydration Hypotonic/Hyponatreamic dehydration Hypertonic/Hypernatreamic dehydration. Monday, 14 November 2016 HAMZAT AND LAYENI 15

16. ISOTONIC/ISONATREAMIC DEHYDRATION. Monday, 14 November 2016 HAMZAT AND LAYENI 16

17. HYPOTONIC/HYPONATREAMIC DEHYDRATION. Results from intake of water or fluids with low solute content e.g. Dextrose infusions. The water is absorbed while sodium loss continues There is deficit of water and sodium but the deficit of sodium is greater Serum sodium concentration is low <130mmol/l The child is lethargic and infrequently may have seizures . Monday, 14 November 2016 HAMZAT AND LAYENI 17

18. HYPERNATREAMIC/HYPERTONIC DEHYDRATION. Monday, 14 November 2016 HAMZAT AND LAYENI 18

19. TREATMENT Because of the associated dangers, hypernatremia should not be corrected rapidly The goal is to decrease the serum sodium by <12 mEq /L every 24 hours, a rate of 0.5 mEq /L/ hr In the child with hypernatraemic dehydration, as in any child with dehydration, the 1st priority is restoration of intravascular volume with isotonic fluid. Monday, 14 November 2016 HAMZAT AND LAYENI 19

20. CLINICAL ASSESSMENT OF DEGREE OF DEHYDRATION – AAP Signs & Symptoms Mild Moderate Severe Weight 3-5% 6% >10% General condition Alert, restless Thirsty, lethargic Cold, sweaty, limp Pulse Normal rate, volume Rapid, weak Rapid, feeble Respiration Normal Deep, rapid Deep, rapid Anterior fontanelle Normal Sunken Very sunken Systolic pressure Normal Normal or low Low, unrecordable Skin elasticity Normal Decreased Markedly decreased Eyes Normal Sunken, dry Grossly sunken Mucus membrane Moist Dry Very dry Urine output Adequate Less, dark Oliguria, anuria Capillary refill Normal <2 sec > 3 sec Estimated deficit 30-50mL/kg 60mL/kg 100mL/kg Monday, 14 November 2016 HAMZAT AND LAYENI 20

21. REVISED WHO GUIDELINE FOR THE CLASSIFICATION OF DEHYDRATION Parameters No dehydration Some dehydration Severe dehydration Appearance Well, alert Restless, irritable Lethargic, or unconscious; floppy Eyes Normal Sunken Very sunken Thirst Drinks normally, not thirsty Thirsty, drinks eagerly Drinks poorly or not able to drink Skin pinch Goes back quickly (<1 second) Goes back slowly (1 second) Goes back very slowly (≥2 seconds) Monday, 14 November 2016 HAMZAT AND LAYENI 21

22. FLUID REPLACEMENT THERAPY Most important goal of fluid replacement therapy is restoration of an adequate effective circulating volume . Replace fluid deficit in dehydration Fluid deficit is calculated from degree of dehydration Fluid deficit (ml) = % dehydration x wt (kg) x 1000mls Give maintenance fluid therapy ± on-going loss . Monday, 14 November 2016 HAMZAT AND LAYENI 22

23. ESTIMATING THE FLUID DEFICIT Check the weight: Rapid changes in weight likely represent changes in TBW. History: diarrhea , vomiting, attempts at replacement urine output. Physical exam findings: Mental status, pulse, BP, body weight, mucous membranes, skin turgor, skin color. Laboratory evaluation: Serum chemistries, hematocrit, and urine studies can guide therapy and check for complications . Monday, 14 November 2016 HAMZAT AND LAYENI 23

24. ORAL REHYDRATION THERAPY Oral rehydration with electrolyte solutions is safe, efficacious and convenient . Can be used as first line therapy in nearly all fluid and electrolyte aberrations except severe circulatory compromise. WHO Oral Rehydration Solution has been very successful with Na=90 mmol /L and glucose=111 mmol /L (2% glucose). Monday, 14 November 2016 HAMZAT AND LAYENI 24

25. ORAL REHYDRATION SOLUTIONS (CONCENTRATIONS IN MMOL/L) Na Glucose K Cl Base Concentration WHO ORS 90 111 20 80 30(BICARB) 311mOsm/kg Rehydrate 75 140 20 65 30(CITRATE) 310mOsm/kg Pedialyte 45 140 20 35 30(CITRATE) 250mOsm/kg Ricelyte 50 170 25 45 34 304mOsm/kg Monday, 14 November 2016 HAMZAT AND LAYENI 25

26. ORS REQUIREMENTS IN DIARRHOEA NO DEHYDRATION 30 – 50ml/kg of ORS over 4hrs Where this is not available other home made fluids SOME DEHYDRATION 75ml/kg of ORS over 4 hrs * Re-assess after 4 hrs, if dehydration persists, Repeat above. Monday, 14 November 2016 HAMZAT AND LAYENI 26 SEVERE DEHYDRATION For IV rehydration, Ringer’s lactate (also called Hartmann’s solution) is recommended. If not available, normal saline can be used Give 100ml/kg of the fluid as shown below: < 12 months old give; 30ml/kg in 1 hour and 70ml/kg in 5 hours ≥12 months old give 30ml/kg in30 minutes and 70ml/kg in 2 1/2 hours Repeat again if the radial pulse is still very weak or not detectable.

27. ReSoMal Oral rehydration salts solution for severely malnourished children Since severely malnourished children are deficient in potassium and have very high levels of sodium, the normal ORS is dangerous for them. They need a solution which contains less sodium and more potassium. Patients are usually also deficient in other minerals like Mg, Cu and Zn and these minerals are added to the special ORS for malnourished children. . Monday, 14 November 2016 HAMZAT AND LAYENI 27

28. ReSoMal composition Glucose 125 mmol /l Sodium 45 mmol /l Potassium 40 mmol /l Chloride 70 mmol /l Magnesium 3 mmol /l Zinc 0.3 mmol /l Copper 0.045 mmol /l Citrate 7 mmol /l. Monday, 14 November 2016 HAMZAT AND LAYENI 28 TYPES OF FLUIDS FOR ORAL THERAPY ORS solution SSS preparation Super ORS: Cereal-based , Amino-acid -based Yoghurt-based drinks Coconut water

29. CONTRAINDICATIONS TO ORT ADMINISTRATION Purging at very high rate[>10-15ml/kg/hr] Persistent vomiting Severe Dehydration Inability or refusal to drink Glucose malabsorption Incorrect preparation or administration of ORS Abdominal distension and ileus. Monday, 14 November 2016 HAMZAT AND LAYENI 29

30. INTRAVENOUS THERAPY Absolute indications for IV therapy are limited. Clearly indicated in shock; sometimes in settings of high ongoing losses or in those children who cannot accomplish rehydration orally . Reestablishing effective circulating volume is the main goal. When continuing IV fluids consider: • Remaining deficit that needs to be replaced (both water and electrolytes) • Ongoing losses (volume and electrolyte composition) • Daily requirements for water and electrolytes • Clinical conditions that can effect use of IV fluids (e.g., cardiac, renal disease) Monday, 14 November 2016 HAMZAT AND LAYENI 30

31. SOLUTION Na mmol /L K mmol /L Cl mmol /L Lactate mmol /L A: Preferred Ringer’s Lactate 130 4 109 28 B: Acceptable Normal Saline[0.9%] 154 154 Half Strength Darrow’s Solution 61 18 52 27 Half normal saline[0.45%] 77 77 C. Unacceptable Glucose[dextrose solutions] Monday, 14 November 2016 HAMZAT AND LAYENI 31

32. REHYDRATION The child with dehydration requires acute intervention to ensure that there is adequate tissue perfusion. This resuscitation phase requires rapid restoration of the circulating intravascular volume and treatment of shock with an isotonic solution, such as normal saline (NS) or Ringer lactate (LR). The child is given a fluid bolus, usually 20 -30mL/kg of the isotonic fluid, over 30 min. to 1 hr The child with severe dehydration may require multiple fluid boluses . Monday, 14 November 2016 HAMZAT AND LAYENI 32

33. REHYDRATION CONT. The initial resuscitation and rehydration phase is complete when the child has an adequate intravascular volume. Typically, the child shows clinical improvement, including a lower heart rate, normalization of blood pressure, improved perfusion, better urine output, and a more alert affect In isonatremic or hyponatremic dehydration, the entire fluid deficit + maintenance is corrected over 24 hr ; a slower approach is used for hypernatremic dehydration Monday, 14 November 2016 HAMZAT AND LAYENI 33

34. MONITORING FLUID THERAPY Proper regulation of the quantity of fluids Examine the patient frequently Weigh the child daily Monitor Fluid Input and Output-including urine and other outputs closely Laboratory parameters-Electrolytes, Urea and creatinine, Hb /PCV, Urinalysis Monday, 14 November 2016 HAMZAT AND LAYENI 34

35. COMPLICATIONS OF FLUID THERAPY COMPLICATIONS DUE TO VOLUME OVERLOAD- Congestive cardiac failure, pulmonary edema COMPLICATIONS DUE TO THE SUBSTANCES IN THE FLUID Anaphylaxis to contents of the fluids, Electrolyte derangement [hypo and hyper natraemia and - kalaemias ] Base deficits. Monday, 14 November 2016 HAMZAT AND LAYENI 35

36. OVERHYDRATION Overhydration,also called water intoxication or dilutional hyponatraemia is a condition in which the body contains too much water . RISK FACTORS Infants (as a result of their small body mass) Chronic illness(malnutrition) Renal disease . Cardia diseases Monday, 14 November 2016 HAMZAT AND LAYENI 36

37. SIGNS AND SYMPTOMS Delirium Cerebrovascular accident seizure Tachypnoea. Blurred vision Muscle cramp and twitching Nausea and vomiting Anorexia Monday, 14 November 2016 HAMZAT AND LAYENI 37 Hypertension Nausea Vomiting Confusion Drowsiness Malaise Headache Seizure(serum sodium <120meq/L)

38. OSMOLALITY PROBLEMS HYPONATREMIA Defined as: serum Na < 130 mEq /L Usually due to too much water for solute, rather than too little sodium. Sodium deficit calculation: [(normal Na( mEq /L)) – (measured Na( mEq /L)] x TBW (L) Use 135mEq/L as normal Na; estimate TBW as 0.6L/kg x body weight (kg ) Symptomatic Hyponatremia: Decreased serum sodium (usually <120mEq/L) with seizures or mental status changes. Hypertonic saline is indicated only in this situation . There is no role for hypertonic saline in the treatment of asymptomatic hyponatremia Monday, 14 November 2016 HAMZAT AND LAYENI 38

39. HYPERNATREMIA Defined as: serum Na > 150 mEq /L Significant neurological effects usually seen with Na > 160 mEq /L Usually due to a relative deficiency of water for normal extracellular solute. Can occur in setting of excess water losses (DI) or loss of Na and water that is dilute compared to serum (diarrhea; Na=60mEq/L ). Rising serum Na leads to rising serum osmolality. Osmoreceptors sense increased osmolality and trigger ADH release. Thirst mechanism is triggered with elevated osmolality. Both mechanisms should return osmolality to normal. Monday, 14 November 2016 HAMZAT AND LAYENI 39

40. HYPOKALEMIA CAUSES 1 . Renal tubular defect (intrinsic or secondary to nephrotoxins ) 2. Starvation 3. Chronic diarrhea or vomiting 4. Diabetic ketoacidosis 5. Hyperaldosteronism 6. Chronic diuretic use 7. Inadequate IV replacement 8. Metabolic alkalosis 9. Magnesium depletion Monday, 14 November 2016 HAMZAT AND LAYENI 40 SYMPTOMS/SIGNS 1 . Muscle weakness, cramps 2. Paralytic 3. Hyporeflexia 4. Lethargy, confusion 5. Prolonged QRS, U-Wave, low voltage T-wave 6. Atrial & ventricular ectopy, increased sensitivity to digitalis TREATMENT (ALL ORDERS MUST BE IN MEQ/L) 1 . Oral replacement: Maintenance = 2 mEq /kg/day. Give additional 1-2 mEq /kg/day as needed. 2. IV replacement a. Maximum concentration through peripheral IV is 60 mEq /L. b. Maximum rate of KCl administration should be 0.3 mEq /kg/ hr or 40 mEq (total)/ hr , whichever is less.

41. HYPERKALEMIA CAUSES 1. Renal failure 2. Hemolysis 3. Tissue necrosis 4. Hypoaldosteronism (e.g., Addison's disease and pseudohypoaldosteronism ) 5. Congenital adrenal hyperplasia 6. Potassium-sparing diuretics (e.g., spironolactone, amiloride ) 7. Overdose of potassium supplements (PO, IV) Monday, 14 November 2016 HAMZAT AND LAYENI 41 SYMPTOMS/SIGNS 1. Primarily cardiac 2. EKG changes: a. Peaked T-Wave b. Increased P-R interval c. Widened QRS d. Depressed ST segment e. AV or intraventricular heart block f. Ventricular flutter, fibrillation 3. Other: tingling, paresthesias , weakness, paralysis TREATMENT 1. Obtain EKG and initiate cardiac monitoring calcium gluconate - 100 mg/kg IV over 5-10 min. sodium bicarbonate - 1-2 mEq /kg IV over 5-10 min prepare for dialysis (used in face of life-threatening arrhythmias ). Kayexalate (Sodium Polystyrene sulfonate) : PO: 15gm once daily or 12hourly. Rectal: 30-50gm

42. CONCLUSION Organizing fluid needs into maintenance, deficit , and replacement therapy can provide a systematic , understandable approach to determining fluid therapy . By paying close attention to the fluid needs of pediatric patients and monitoring response to fluid therapy, the pediatric care givers can have a positive influence on the health of the child . Monday, 14 November 2016 HAMZAT AND LAYENI 42

43. Monday, 14 November 2016 HAMZAT I 43 LAYENI

44. REFERENCES Mary Cunliffe MB BS FRCA : Fluid and electrolyte management in children . British Journal of Anaesthesia | CEPD Reviews | Volume 3 Dr. Symons: Clinical Fluid & Electrolyte Management. Guidelines for the Use of Parenteral and Enteral Nutrition in Adult and Pediatric Patients. 2002; vol . 26 Rachel S. Meyers, PharmD : Pediatric Fluid and Electrolyte Therapy. Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Saint Barnabas Medical Center, Piscataway , New Jersey Dr. Suresh G. Nair and Dr . Rakhi Balachandran: Perioperative fluid and electrolyte management in paediatric patients. INnAdIiRan, BJ.A ALnAaCeHstAh.N 2D0R04A;N 4 8: (P5E) R: 3IO55P-E3R64 Dr IKUEROWO AO: Fluids & electrolytes management. Lagos State University Teaching Hospital, Ikeja. Monday, 14 November 2016 HAMZAT AND LAYENI 44