DEHYDRATION SOAD JABER 2009 Maintenance fluid replacement Normal

DEHYDRATION SOAD JABER 2009

Maintenance fluid replacement Normal fluid replacement ECF Thirst ADH Aldosterone Obligatory water loss * urine, sweat , stool *Insensible water loss 70% skin 30% lung no solute content Osmotic Hydrostatic ICF

Some causes of dehydration Vomiting Metabolic alkalosis Hypokalemia Hyponatremic dehydration Iso, hyper natremic dehy Hyper tonic dehydration sweating diarrhea. Salt loss 1°C → 10% water loss Prolonged gastric aspiration hypo natremic dehydration Diarrhea DKA Cystic fibrosis Fever Intestinal Obstruction Diabetes Insipidus Renal disease Pure water loss hypernatremic dehydration. Na+water loss Iso OR hyponatromic deh

Dehydration Simple deficit in body water Contraction of body fluid space Both water and electrolyte contents Loss of ECF ± ICF

Deficit : Cumulative body water and electrolyte losses that occur prior to clinical presentation. Body losses: n n Absolute amount of water lost always Exceeds the amount of solute loss. Every dehydration tend to be hypertonic , Only kidneys prevent hypertonicity.

Types Isotonic: 70% most common Na 135 -145 meq/L

cont Hypertonic: 20% - Na 145 meq /L - Water loss> solute - Renal circulation impaired → kidney can't excrete solute. -? Salt intake, - May occur in well nourished obese infants follow acute process with marked anorexia and fulminant diarrhea.

CONT hypertonic p - Signs of dehydration less than the actual degree of dehydration fluid shift ICF → ECF p Doughy skin p Parched tongue p Almost near normal B. P. Complications: p Shrinkage of brain cells → hematoma →Bleeding p Brain edema while treatment p Coma Seizure Associated with acidosis Hypokalemia

HYPOTONIC 10%- In an infant or a child with diarrhea whose intake is electrolyte free. Weak tea, , Rice water, , diluted milk - Chronically malnourished child with bouts of mild to moderate diarrhea and poor intake. -Fluid shift ECF → ICF - Well preserved intracellular volume. -Collapse and shock with degree of dehydration decrease Renal flow with milder degree of dehydration.

HYPOTONIC Complication p Convulsion due to hyponatremia p Circulatory collapse and shock even with milder degree of dehydration n n Extra cellular fluid losses Intra cellular fluid shift Volume depletion more than actual water loss Profound volume depletion will lead to ±Renal failure -shock

DEGREE 10% Moderate p Skin p fontanels depressed Oliguria tears OR absent B. P. Still well maintained Orthostatic B. P. p p p turger elasticity tenting Sunken eyes Obvious to the parents not to the physician.

Cont, Moderate - Severe p Hypovolemia due to contraction of plasma volume p Hypotension p Cold extremities p Tachycardia

Severe dehydration 15% Circulatory collapse B. P. Cool cyanotic sweaty extremities Mottled skin Shock Death

Mod 5 -9% Blood Pressure Pulse pressure Heart rate Skin Fontanel Mucous memo Extremities Mental status Urine output Thirst Mild <5% N to Normal Turgor Normal Slightly dry Dry Perfuse Delay capill refill Normal N or lethargic Slightly Severe >10% Tachycardia turgor Sunken Dry Cool , mottled Lethargic, coma Absent

Management of: Fluid and electrolyte Refeeding 1. Dehydration: More severe in children a. greater basal fluid + elect requirement / kg b. dependent on others for the demands Assess the degree of dehydration: Clinical signs and symptoms Ongoing losses daily requirement

Investigation Lab: 1. 2. 3. Repeat all at 6 - 12 - 24 h. CBC Hemo concentration Hb Hct. Plasma osmolality Urea + electrolytes * Na. . . Type of dehydration Normal Acidosis Na Renal function with significant stool losses with severe vomiting - alkalosis NA with treatment with high glucose treatment with alkali * HCO 3 loss will lead to acidosis with severe diarrhea * Urea nitrogen & Creatinine

Rehydration therapy * I. V. * Oral I. V. Initial therapy Resuscitation fluid (10 -20 ml / hour) n n n Designed to expand extra cellular fluid volume rapidly especially plasma Improve circulatory and renal function Prevention or treatment of shock Fluid type: Isotonic saline. 0. 9% [ 0. 9% N. S. ]

Initial therapy (Continuation) p p If with severe acidosis Ringer lactate Na 140 meq/L K 115 meq/L HCO 3 25 meq/L Dextrose 5% If in shock Plasma expander *Alb 5% *Blood 10 ml/kg n n Repeat once or twice till patient is hemo-dynamically stable. No hypotonic saline →may lead to cerebral edema

II. Subsequent therapy p p Provision of maintenance fluid and electrolyte Replacement of existing deficits. Replacement of ongoing losses. To be re-checked at 8 hourly interval. 1)Maintenance - Fluid requirement /kg /24 hour. -Constant everyday -Maintenance calculated on daily basis regardless to deficit or ongoing losses.

II. Subsequent therapy. (maintenance) How 1 -10 kgs 10 -20 kgs > 20 kgs 100 mls/kg/24 h 50 mls/kg/24 h 20 mls/kg/24 h Example: Child weight is 25 kg what is his maintenance? 1 st 10 kgs 2 nd 10 kgs > 20 kg 10 x 100 10 x 50 5 x 20 = 1000 mls = 500 mls = 100 mls 1600 mls/24 h

2)Deficits *Degree of dehydration: 5% dehydration (mild) p 10% dehydration ( moderate) p 15% dehydration (Severe) p *Type of dehydration: According to Na level p Rate p Type of fluid 50 mls/kg 100 mls/kg 150 m. Is/kg

A) Isotonic (Isonatremic) dehydration. Loss of isotonic fluid from the body -No osmotic gradient between Intra + Extra cellular fluids. -Full deficit correction over 24 hours 1/2 over 1 st 6 -8 h 1/2 over 16 -18 h. Type of fluid D 5 in 0. 2 N. S. D 5 in 0. 45 N. S.

B). Hypo natremic dehydration. -Na loss more than water loss. ex. * with dysentery *Treatment with low Na fluid - Rate Full deficit correction over 36 h , 1/2 over 6 -8 h. . the rest over 16 -18 hour. -Depend on. . . level of Na …degree of dehydration

Type of fluids: D 5 IN 0. 45 N. S. D 5 IN 0. 9 N. S. depend on Na level p Usually no need to add Na to the fluid as correction of dehydration will correct Na. If after correction of dehydration still Na loss Add: 6 meq/kg Na cl Max 12 ml/kg of 3% Na cl over 6 h p or Calculate Na deficit = (135 – actual Na level) x 0. 3 x B. W. in kg.

C) Hyper natremic dehydration: -More serious. -Fluid therapy replacement can be difficult. -Severe hyper osmolality may result in cerebral damage and Hge. -Seizures occur during treatment as serum Na returning to normal due to rapid correction, or the use of hypotonic fluid. Treatment of convulsion: *Anti convulsant *Na cl -

*Excess movement of water into cerebral cells during rehydration with hypotonic saline , or rapid correction will lead to → Cerebral edema May be irreversible or fatal Type of fluid -Slow rate in more important than type of fluid -Na drop should not be more than 10 meq/L/ 24 hour D 5 0. 45 N. S.

Rate: Very slow Can be done over days Usually 48 - 72 hours ***Example: Child weight 30 kg with 10% dehydration What is his fluid requirement? 1)Maintenance: 30 kg 10 x 100 = 1000 10 x 50 = 500 1700 mls/ 24 h 10 x 20 = 200 2)Deficit 10% dehydration = 100 mls/kg 100 x 30 = 3000 m. Is Type and rate according to type of dehydration

3). Ongoing losses: --Continuous pathological losses Stool - diarrhea Vomitus N. G. tube *Small amount *Moderate amount *Large amount 6 -8 h. 50 mls/time 100 mls/time 150 mls/time To be added to deficit, calculated every

ORS To all patient but: 1. 2. 3. Severe dehydration in patient whose care giver can’t administer fluids. If ongoing losses can’t be compensated orally. Severe vomiting. Value: Rapid rehydration with rapid replacement of ongoing losses during the first 4 -6 hours. Once rehydrated – oral maintenance solutions.

Home remedies? n n n Decarbonated soda beverages Fruit juices Tea Not suitable: n n n Inappropriate high osmolarities due to CHO conc. Low Na content → hypo natremia Inappropriate CHO to Na ratio

Oral rehydration solution When to use it? Contraindication …. . Types Na meq/L K meq/L C 1 meq/L HCO 5 meq/L Glucose g/dl Types …. WHO 90 20 80 30 2% Rate…. . Pedialyte Rate: 45 20 35 30 citrate 2. 7% 50 ml/kg …. within 4 hours for patient with mild dehydration 100 ml/kg … within 6 hours for patient with moderate dehydration Small amounts + short intervals

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