Fluid and Electrolyte Balance Objectives PEDIATRIC FLUID AND ELECTROLYTE BALANCE AND DEHYDRATION Mary Fran Hazinski, RN, MSN, FAAN, FAHA Professor, Vanderbilt University School of Nursing Nashville, Tennessee
At the end of the presentation the participant will be able to:
Describe the normal distribution of body water and factors causing free water shift into and out of the vascular space Describe calculation of estimated fluid requirements using body weight and body surface area Describe the management of sodium and potassium imbalances
© Mary Fran Hazinski: Please do not reproduce without permission
© Mary Fran Hazinski
FLUID AND ELECTROLYTE BALANCE IN CHILDREN
For further information see
Distribution of Body Water Calculation of Fluid Requirements Electrolyte Imbalances
From: Hazinski, MF (Ed)., Nursing Care of the Critically Ill Child, edition 3, Saint Louis, 2012, Mosby/Elsevier. © Mary Fran Hazinski
FLUID AND ELECTROLYTE BALANCE IN CHILDREN Distribution of Body Water Calculation of Fluid Requirements Electrolyte Imbalances
© Mary Fran Hazinski
TOTAL BODY WATER Location Beyond 6 Weeks of Age EXTRACELLULAR 33%
8% VASCULAR SPACE © Mary Fran Hazinski
25% INTERSTITIAL SPACE
INTRACELLULAR 67%
67% CELLULAR SPACE
© Mary Fran Hazinski from Roberts KE. Fluid, electrolyte and endocrine problems, In Hazinski MF (Ed), Nursing Care of the Critically Ill Child, edition 3. Saint Louis, 2012, Mosby
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From Guyton, Textbook of Physiology
© Mary Fran Hazinski From Guyton, Textbook of Physiology
© Mary Fran Hazinski
EXTRAVASCULAR FLUID SHIFT
INTRAVASCULAR FLUID SHIFT
With Acute FALL in Serum Osmolality
With Acute RISE in Serum Osmolality
EXTRACELLULAR
VASCULAR SPACE
INTERSTITIAL SPACE
INTRACELLULAR
CELLULAR SPACE
© Mary Fran Hazinski from Roberts KE. Fluid, electrolyte and endocrine problems, In Hazinski MF (Ed), Nursing Care of the Critically Ill Child, ed. 3. Saint Louis, 2012, Mosby
EXTRACELLULAR
VASCULAR SPACE
INTRACELLULAR
INTERSTITIAL SPACE
CELLULAR SPACE
© Mary Fran Hazinski from Roberts KE. Fluid, electrolyte and endocrine problems, In Hazinski MF (Ed), Nursing Care of the Critically Ill Child, ed. 3. Saint Louis, 2012, Mosby
BRAIN CELL PROTECTION
POTENTIAL BRAIN CELL INJURY
With Intravascular Fluid Shift
With Extravascular Fluid Shift
EXTRACELLULAR
INTRACELLULAR
EXTRACELLULAR
Other Cells
VASCULAR SPACE
INTERSTITIAL SPACE
BRAIN CELLS
© Mary Fran Hazinski from Roberts KE. Fluid, electrolyte and endocrine problems, In Hazinski MF (Ed), Nursing Care of the Critically Ill Child, ed. 3. Saint Louis, 2012, Mosby
INTRACELLULAR
Other Cells
VASCULAR SPACE
INTERSTITIAL SPACE
BRAIN CELLS
© Mary Fran Hazinski from Roberts KE. Fluid, electrolyte and endocrine problems, In Hazinski MF (Ed), Nursing Care of the Critically Ill Child, ed. 3. Saint Louis, 2012, Mosby
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ESTIMATION OF SERUM OSMOLARITY
ANTIDIURETIC HORMONE (ADH/AVP) Normal Function
2 x [Na+]
=
_______
+ [Glucose] ÷ 18 =
_______
+ [BUN] ÷ 2.8 NORMAL
_______ 280-295 mOsm/L
= =
Produced in hypothalamus, released by pituitary in response to: - rise in serum osmolality - hypovolemia - hypotension
Increases permeability of renal collecting ducts and distal tubule to water, producing renal water retention, fall in serum osmolality
© Mary Fran Hazinski
© Mary Fran Hazinski
URINE AND SERUM OSMOLALITY Normal and SIADH and CSW
SYNDROME OF INAPPROPRIATE ADH SECRETION (SIADH)
Na+
High circulating levels of ADH in absence of physiologic stimulus Produces dilutional hyponatremia (water intoxication) Typically urine output is low (< 1 mL/kg/hr) Can be associated with CNS disorders, respiratory disorders, ectopic autonomous ADH secretion
Serum Urine
500 mOsm/L**
CEREBRAL SALT WASTING SYNDROME Typically develops 2-7 days after CNS injury Probably caused by abnormal secretion of natriuretic peptide Produces sodium diuresis, volume contraction and hyponatremia Typically urine output is high
Restrict water intake
Administer isotonic saline
Monitor neurologic status; administer 3% saline if neurologic symptoms develop
Consider diuresis
© Mary Fran Hazinski
260 mOsm/L < 260 mOsm/L
© Mary Fran Hazinski
SYNDROME OF INAPPROPRIATE ADH SECRETION: Management
1 Low Increased
>1 High Increased
Administer fluids and sodium (aggressive fluid resuscitation)
Monitor neurologic status; administer 3% saline if neurologic symptoms develop
Treatment with high-dose fludrocortisone (0.2-0.4 mg/day) may be effective
© Mary Fran Hazinski
© Mary Fran Hazinski
DIABETES INSIPIDUS (DI) Management
DIABETES INSIPIDUS (DI): Pathophysiology
Decreased secretion (central/neurogenic) or
Replace urine fluid losses (q 10-15 minutes) plus maintenance fluid requirements
Administer ADH (central/neurogenic)
Monitor electrolyte balance
Identify, treat cause
decreased renal response (nephrogenic)to ADH
Urine not concentrated by kidneys
Significant water loss in urine can rapidly produce hypovolemia, hemoconcentration
Urine volume high with low urine specific gravity, osmolality and sodium © Mary Fran Hazinski
© Mary Fran Hazinski
Slide courtesy of Dr. Norman Staub, UCSF,
© Mary Fran Hazinski
© Mary Fran Hazinski
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FLUID AND ELECTROLYTE BALANCE IN CHILDREN Distribution of Body Water Calculation of Fluid Requirements Electrolyte Imbalances
From Winters, RW, The Body Fluids in Pediatrics, 1973, Little Brown
© Mary Fran Hazinski
© Mary Fran Hazinski
© Mary Fran Hazinski
© Mary Fran Hazinski
INTRAVASCULAR VOLUME Assessment Systemic perfusion Skin turgor, mucous membranes, conjunctiva, fontanelle Systemic and pulmonary edema Laboratory data (BUN, serum Na+, serum osmolality, urine specific gravity, possible urine chemistries)
© Mary Fran Hazinski
© Mary Fran Hazinski
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© Mary Fran Hazinski
© Mary Fran Hazinski
INTRAVASCULAR VOLUME Factors Influencing Fluid Shifts Absolute volume status Osmotic gradients (sodium) Capillary pressure, permeability Colloid osmotic pressure (proteins)
© Mary Fran Hazinski
© Mary Fran Hazinski
From Elaine Daily, Bedside Hemodynamic Monitoring, Mosby
Slide courtesy of American Edwards
© Mary Fran Hazinski
© Mary Fran Hazinski
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DAILY MAINTENANCE FLUID REQUIREMENTS WEIGHT First 72 hrs
DAILY BASE RATE 60-100 ml/kg/day
0-10 kg
100 ml/kg/day
11-20 kg
1000 ml + 50 ml/kg/day for kg 11-20
21-30 kg
1500 ml + 25 ml/kg/day for kg 21-30
© Mary Fran Hazinski
© Mary Fran Hazinski
HOURLY MAINTENANCE FLUID REQUIREMENTS WEIGHT First 10 kg + Second 10 kg + Third 10 kg
HOURLY BASE RATE 4 ml/kg/hour + 2 ml/kg/hour + 1 ml/kg/hour
© Mary Fran Hazinski
© Mary Fran Hazinski
MAINTENANCE FLUID REQUIREMENTS 1500 ml/m2 body surface area (BSA)/day Insensible water losses: 300-400 ml/m2 BSA/day
Formula to estimate BSA: (4 X kg wt) + 7 = m2 BSA 90 + (kg wt) © Mary Fran Hazinski
FLUID ADMINISTRATION RATE Tailoring Fluid Administration
Consider clinical condition
Potential increased requirements for dehydration, phototherapy (non LED bililight)
Fever increases IWL 0.42 ml/kg/hr/o C > 37o C
Once patient euvolemic, reduce intake for: congestive heart failure, respiratory failure, renal failure or increased intracranial pressure © Mary Fran Hazinski
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© Frank Netter
© Mary Fran Hazinski
© Mary Fran Hazinski
FLUID AND ELECTROLYTE BALANCE IN CHILDREN Distribution of Body Water Calculation of Fluid Requirements Electrolyte Imbalances
© Mary Fran Hazinski
HYPONATREMIA Potential Causes Sodium loss Adrenocortical hyperplasia Water intoxication SIADH Severe hyperglycemia
© Mary Fran Hazinski From Guyton, Textbook of Physiology
EXTRAVASCULAR FLUID SHIFT With Acute FALL in Serum Osmolality EXTRACELLULAR
VASCULAR SPACE © Mary Fran Hazinski
INTERSTITIAL SPACE
INTRACELLULAR
CELLULAR SPACE
© Mary Fran Hazinski from Roberts KE. Fluid, electrolyte and endocrine problems, In Hazinski MF (Ed), Nursing Care of the Critically Ill Child, ed. 3. Saint Louis, 2012, Mosby
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Correction of Sodium for Hyperglycemia For every 100 mg/dl rise in glucose above normal, expect serum sodium to fall 1.6 mEq below 135 mEq/L When serum glucose falls, serum sodium should rise proportionately
HYPONATREMIA Management Administer sodium or eliminate free water or both Calculate estimated deficit (use 0.5 below for women) and replace Correct hyponatremia at rate of 0.5 mEq/L/hour or 10-12 mEq/L/day Monitor neurologic status; administer 3% saline if needed (3-5 ml/kg, 513 mEq/L)
© Mary Fran Hazinski
© Mary Fran Hazinski
HYPERNATREMIA Potential Causes
INTRAVASCULAR FLUID SHIFT With Acute RISE in Serum Osmolality EXTRACELLULAR
Salt gain
Free water loss
Diabetes insipidus
VASCULAR SPACE
INTRACELLULAR
INTERSTITIAL SPACE
CELLULAR SPACE
© Mary Fran Hazinski from Roberts KE. Fluid, electrolyte and endocrine problems, In Hazinski MF (Ed), Nursing Care of the Critically Ill Child, ed. 3. Saint Louis, 2012, Mosby
© Mary Fran Hazinski
EXTRAVASCULAR FLUID SHIFT With Acute FALL in Serum Osmolality EXTRACELLULAR
VASCULAR SPACE
INTERSTITIAL SPACE
INTRACELLULAR
CELLULAR SPACE
© Mary Fran Hazinski from Roberts KE. Fluid, electrolyte and endocrine problems, In Hazinski MF (Ed), Nursing Care of the Critically Ill Child, ed. 3. Saint Louis, 2012, Mosby
From Guyton, Textbook of Physiology © Mary Fran Hazinski
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INTRAVASCULAR K+ SHIFT With Acidosis and Fall in Serum pH K+ concentration changes in a direction opposite the pH change H+ K+ H+ K+ H+ K+ H+
K+
H+
H+
H+ K+ H+H+ K+ H+
VASCULAR SPACE
K+
INTRACELLULAR K+ SHIFT With Alkalosis and Rise in Serum pH K+ DECREASES ~ 0.3 mEq/L for every 0.1 unit increase in pH K+
H+
H+
H+ K+ K+
H+ H+
H+
Dilution Excessive potassium loss renal tubular acidosis hypomagnesemia and renal potassium loss extrarenal losses
Inadequate potassium administration Alkalosis/rising pH © Mary Fran Hazinski
HYPERKALEMIA Potential Causes Decreased potassium excretion Excessive potassium administration Significant hemolysis (tumor lysis syndrome) Redistribution Acidosis
© Mary Fran Hazinski
K+
K+ H+
K+
CELLULAR SPACE
© Mary Fran Hazinski from Roberts KE. Fluid, electrolyte and endocrine problems, In Hazinski MF (Ed), Nursing Care of the Critically Ill Child, ed. 3. Saint Louis, 2012, Mosby
HYPOKALEMIA Potential Causes
K+
H+
VASCULAR SPACE
CELLULAR SPACE
© Mary Fran Hazinski from Roberts KE. Fluid, electrolyte and endocrine problems, In Hazinski MF (Ed), Nursing Care of the Critically Ill Child, ed. 3. Saint Louis, 2012, Mosby
K+
K+ K+ H+ K+
HYPOKALEMIA Management Administer potassium infusion over 1-3 hours (0.5-1 mEq/kg) Monitor ECG (U wave, arrhythmias) Consider central IV administration Label IV tubing Consider addition to daily intake
© Mary Fran Hazinski
08:23am: 16 year-old patient with end-stage renal failure with complaint of weakness after missing last dialysis appointment. Patient alert,talking; weak, BP=80/55 mmHg. Case details and slide courtesy of Richard Cummins, MD University of Washington, Seattle, WA
© Mary Fran Hazinski
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HYPERKALEMIC ECG CHANGES: Peaked T waves, Flattened or absent P waves, Prolonged P-R, Prolonged QRS, “Sine wave”, VT, VF
• 08:27am : now 4 minutes later. Why such marked improvement?
Slide courtesy of Richard O. Cummins, MD, Seattle
Slide courtesy Richard O. Cummins, MD, Seattle
O8:23 08:27
(continuous strip)
O8:27
Rx??
© Mary Fran Hazinski
• 08:31am: final strip; 8 minutes from start. • What is full regimen for this problem?
© Mary Fran Hazinski
Slide courtesy of Richard O. Cummins, MD, Seattle
HYPERKALEMIA Management Stabilize Excitable Tissues: CaCl or Ca Gluconate Shift K+ Into Cells: Sodium bicarbonate, Glucose + insulin, Beta-agonist (albuterol) Remove K+ From Body: Furosemide, Cation exchange resins, Dialysis Note: Low level evidence (chiefly small case series) supports recommendations
O8:31 am
© Mary Fran Hazinski
© Mary Fran Hazinski
Hyper- and Hypoglycemia Infants have high glucose needs and low glycogen stores, so can rapidly become hypoglycemic Hyperglycemia associated with worse neurologic outcome in children Glucose control in critically-ill adults associated with reduced mortality; hypoglycemia also problematic
© Mary Fran Hazinski
© Mary Fran Hazinski
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Glycemic Control in Children
Intensive insulin therapy for pediatric intensive care, Vlasselaers et al, Lancet 2009
Recent publications
© Mary Fran Hazinski
Hirshberg EL, Sward KA, Faustino EVS, Nadkarni VM, Agus MSD, Morris AH, Lacroix J. Clinical equipoise regarding glycemic control: a survey of pediatric intensivist perceptions, Pediatr Crit Care Med 2013; 14:0-0 (published online ahead of print). Tofil NM, Prabhakaran P. Glucose—more data, still no answers (editorial). Pediatr Crit Care Med 2013; 14:1:111-112. Ulate KP. A critical appraisal of Vlasselaers D, Milants I, Desmet L et al: intensive insulin therapy for patients in paediatric intensive care: a prospective, randomized controlled study. Lancet 2009; 373:547-556. Pediatr Crit Care Med 2011; 12:455-458.
© Mary Fran Hazinski
Vlasselears, Lancet, 2009
FLUID AND ELECTROLYTE BALANCE IN CHILDREN
Conclusions
Hyperglycemia is common in children requiring mechanical ventilation and/or vasoactive infusions Hyperglycemia is independently associated with mortality Glycemic control in many pediatric critical care units maintains serum glucose < 150 mg/dL but not as low as fasting serum glucose. More data needed
Distribution of Body Water Calculation of Fluid Requirements Electrolyte Imbalances Dehydration
© Mary Fran Hazinski
© Mary Fran Hazinski
DEHYDRATION
MILD ISOTONIC DEHYDRATION
Definitions and Classifications
Clinical Description
Definition: Total output of all fluids and electrolytes exceeds intake Classified by severity: mild, moderate, severe Classified by effect on serum sodium:
hypotonic/hyponatremic isotonic hypertonic/hypernatremic
© Mary Fran Hazinski
Eyes sunken, mucous membranes dry Tachycardic but BLOOD PRESSURE AND RESPIRATORY RATE NORMAL Child irritable, ill 5% Weight loss or less (3% in adolescents) Estimated 50 ml/kg fluid deficit
© Mary Fran Hazinski
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MODERATE ISOTONIC DEHYDRATION: Clinical Presentation Signs of peripheral circulatory failure present (cool extremities, decreased urine output) but BLOOD PRESSURE NORMAL 5-10% Weight loss (4-7% in adolescent) Estimated 100 ml/kg deficit
SEVERE ISOTONIC DEHYDRATION: Clinical Presentation DECOMPENSATED SHOCK PRESENT, including hypotension Child appears moribund > 10 % Weight loss (> 7% in adolescent) Estimated 150 ml/kg fluid deficit
© Mary Fran Hazinski
© Mary Fran Hazinski
ISOTONIC DEHYDRATION
HYPOTONIC DEHYDRATION
Pathophysiology and Management Priorities
Pathophysiology and Management Priorities
Loss of sodium proportional to loss of water so serum sodium normal Fluid loss proportional from all compartments Clinical signs as described Replace deficit while giving maintenance fluids and maintaining electrolyte balance over 24-48 hours
© Mary Fran Hazinski
Loss of sodium > loss of water Serum sodium < 125-130 mEq/L Fluid loss predominantly from intravascular compartment so clinical signs worse for any fluid deficit (severe signs with moderate deficit) Fluid resuscitation often necessary Replace deficit over 24 hours (50% first 8 hrs)
© Mary Fran Hazinski
HYPERTONIC DEHYDRATION Pathophysiology and Management Priorities
EXTRAVASCULAR FLUID SHIFT With Acute FALL in Serum Osmolality EXTRACELLULAR
INTRACELLULAR
VASCULAR SPACE
INTERSTITIAL SPACE
CELLULAR SPACE
© Mary Fran Hazinski from Roberts KE. Fluid, electrolyte and endocrine problems, In Hazinski MF (Ed), Nursing Care of the Critically Ill Child, ed. 3. Saint Louis, 2012, Mosby
Loss of water > loss of sodium Serum sodium > 150-155 mEq/L Fluid loss predominantly from extravascular compartment so clinical signs less severe despite significant fluid deficit (moderate signs despite severe deficit) Replace deficit over 48 hours--prevent rapid fall in serum sodium concentration © Mary Fran Hazinski
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INTRAVASCULAR FLUID SHIFT
EXTRAVASCULAR FLUID SHIFT
With Acute RISE in Serum Osmolality
With Acute FALL in Serum Osmolality
EXTRACELLULAR
VASCULAR SPACE
INTRACELLULAR
INTERSTITIAL SPACE
EXTRACELLULAR
CELLULAR SPACE
© Mary Fran Hazinski from Roberts KE. Fluid, electrolyte and endocrine problems, In Hazinski MF (Ed), Nursing Care of the Critically Ill Child, ed. 3. Saint Louis, 2012, Mosby
VASCULAR SPACE
Summary Questions
© Mary Fran Hazinski
© Mary Fran Hazinski
Website for Hazinski MF, Nursing Care of Critically Ill Child, ed 3
References
http://portals.elsevier.com/portal/hazinski
This custom website provides 20% discount and free shipping
© Mary Fran Hazinski
CELLULAR SPACE
FLUID AND ELECTROLYTE BALANCE AND DEHYDRATION
Principles of Therapy Achieve, maintain IV/IO access Support systemic perfusion Replace volume deficit Administer maintenance fluids Replace ongoing losses Restore, maintain electrolyte balance Monitor organ system function
INTERSTITIAL SPACE
© Mary Fran Hazinski from Roberts KE. Fluid, electrolyte and endocrine problems, In Hazinski MF (Ed), Nursing Care of the Critically Ill Child, ed. 3. Saint Louis, 2012, Mosby
PEDIATRIC DEHYDRATION
INTRACELLULAR
Blaney, F. Renal problems. In In Hazinski MF (Ed), Nursing Care of the Critically Ill Child, ed 3, Saint Louis, 2012, Mosby. Choong K, Kho ME, Menon K, Bohn D. Hypotonic versus isotonic saline in hospitalized children: a systematic review. Arch Dis Child, 91:828-835, 2006. Levin DL. Cerebral edema in diabetic ketoacidosis. Pediatr Crit Care Med 2008;9(3): 320-329. Roberts K. Fluid, electrolyte and endocrine problems. In Hazinski MF (Ed), Nursing Care of the Critically Ill Child, ed 3, Saint Louis, 2013, Mosby. See, also, articles on glycemic control cited in section regarding serum glucose.
© Mary Fran Hazinski
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Diabetic Ketoacidosis Cerebral Edema Diagnostic Criteria Abnormal motor, verbal response to pain Decorticate or decerebrate posture Cranial nerve palsy (esp III, IV, VI) Abnormal neurogenic respiratory pattern Major criteria:
Altered mentation, fluctuating LOC Sustained HR deceleration (>20/min)not associated with improvement Age-inappropriate incontinence Levin, 2009 from Muir, 2004
ANION GAP Definition: Difference between positivelycharged ions (Na+ and K+) and negativelycharged ions (Cl- and NaHCO3-) GAP = { [Na+] + [K+]} -- { [Cl-] + [HCO3 -]} Normal gap = 10-12 mEq/L Lactic acidosis associated with shock produces an increased anion gap
© Mary Fran Hazinski
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