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Terapêutica hidro-eletrolítico
em pediatria
Antonio [email protected]
Médico coordenador
Unidade de Medicina Intensiva Pediátrica
Unidade de Medicina Intensiva Neonatal
Hospital Padre Albino
Professor de Pediatria nível II
Faculdades Integradas Padre Albino
Catanduva / SP
2011
Conceitos básicos
FisiologiaBioquímica das soluções
Íons Intra e Extra Celular
Cell Cytosol (mEq/L) Plasma (mEq/L)
K + 140 4
Na + 12 145
Cl -- 4 116
HCO 3-- 12 24
Anions * 138 9
Mg 2+ 0.8 1.5
Ca 2+ <0.0002 1.8
*Anions include phosphate, sulfate, and proteins with a net negative charge.
10
Serum Osmolality
• Normal: 275 – 295 mOsm/L
Isotonic
• < 275 mOsm/L = Hypotonic
• > 295 mOsm/L = Hypertonic
Total body water
ECF=1 liter ICF=0
Intravascular
=1/4 ECF=250 ml
1 Litro de SF 0.9%
Interstitial=3/4 of
ECF=750ml
1 litro de SG 5%
Total body water=1 liter
ECF=1/3 = 300ml ICF=2/3 = 700ml
Intravascular
=1/4 of ECF~75ml
Indicação de suporte hidro-eletrolíticoendovenoso
•Impossibilidade de uso da VO•Tratamento de distúrbios hidro-eletrolíticos•Necessidade do uso de medicamentos EV
Príncipios para prescrição do suporte hidro-eletrolítico endovenoso
•Quanto volume ?
•Qual solução?
•Doença de base•Condição hidro-eletrolítica•Idade•Peso
Quanto volume?
• Condição hidro-eletrolítica (reposição)
• Necessidades basais (perdas fisiológicas)
• Perdas anormais
Quanto volume?
Necessidades basais
(perdas fisiológicas)
Holliday MA, Segar WE. The maintenance
need for water in parenteral fluid
therapy. Pediatrics 1957;19(5):823-32.
Quanto volume?Holliday MA, Segar WE. The maintenance need for
water in parenteral fluid therapy. Pediatrics
1957;19(5):823-32.
The main factor contributing to the
development of hospital acquired
hyponatremia is routine use of hypotonic
fluids
Excess arginine vasopressin (ADH)
NATURE CLINICAL PRACTICE NEPHROLOGY JULY 2007 VOL 3 NO 7
Patients at greatest risk of developing
hyponatremic encephalopathy
following hypotonic fluid
administration
children,postoperative patients,
brain injury or infection,
pulmonary disease or hypoxemia.
J Pediatr 2004;145:584-7.
Holliday MA, Segar WE. The maintenance need for water in parenteral fluid therapy. Pediatrics 1957;19:823-32.
Standard intravenous maintenance therapy is designed to replace ongoing physiological water losses when oral intake is suspended.
An uncommon exception is the syndrome of inappropriate antidiuretic hormone (SIADH) secretion.
In general, patients who had elevated ADH and were given hypotonic saline did not lower ADH and often remained hyponatremic; those who had elevated ADH and were given isotonic saline did lower ADH and generally were normonatremic
25 of 27 acutely ill children with hyponatremia had elevatedplasma ADH levels.
Acta Pediatr 1996;85:550-3
More children with diarrheal dehydration and elevated ADH levels who were given 0.45% saline [77 mEq/L] became hyponatremic than did those who were given isotonic saline [154 mEq/L].
Neville KA, O’Meara M, Verge CF, Walker JL. Normal saline is betterthan half normal saline for rehydration of children with gastroenteritis. Presentedas poster #866 at the Pediatric Academic Society’s annual meeting,Seattle, Wash 2003.
Prospective studyChildren with meningitis and elevated ADHIsotonic saline plus maintenance or maintenance alone
Those given isotonic saline then maintenance lowered ADH, while those given maintenance alone did not.
J Pediatr 1991;118:996-8
Liberadores não-osmóticos de ADH
• Instabilidade hemodinâmica
• Manutenção da PA (Homeostase)
• Hipotensão , hipovolemia
– Relação exponencial com os níveis de ADH
– Mediada por barorreceptores (atrio, aorta, seio carotídeo)Thrasher TN. Arterial baroreceptors control plasma vasopressin responses to graded hypotension in conscious dogs. Am J Physiol Regul Integr Comp Physiol 2000;278(2):R469-75.
– Angiotensina II estimula a liberação de ADHKeil LC. Release of vasopressin by angiotensin II. Endocrinology 1975;96(4):1063-5.
Liberadores não-osmóticos de ADH
• Doenças pulmonares
• Ventilação mecânica
• Distúrbios neurológicos meningite, encefalite,
tumores, traumaKaplan SL, Feigin RD. The syndrome of inappropriate secretion of
antidiuretic hormone in children with bacterial meningitis. J Pediatr
1978;92(5):758-61.
Liberadores não-osmóticos de ADH
• Hipoglicemia
Baylis PH. Arginine vasopressin response to
insulin-induced hypoglycemia in man. J Clin
Endocrinol Metab 1981;53(5):935-40.
• Hipoxia, hipercarbia
• Estresse, medo, dor
• Postoperatório (íleo)
HipovolemiaHipovolemia
HipotensãoHipotensão
Nausea, Nausea, vomito
vomito
BronquioliteBronquiolite
Postoperat
Postoperatóóriorio
medomedo
dordor
EstresseEstresse
Drogas
Drogas
DoenDoenççasas Respiratorias
Respiratorias
DoenDoenççaa neurolneurolóógicagica
Hipoglicemia
Hipoglicemia
Qual criançainternada não
apresenta riscode SIADH?
ApropriadaApropriada secresecreççãoão de H ADde H AD InapropriadaInapropriada secresecre ççãoão de H ADde H AD
RetenRetenççãoão renal de renal de ááguagua
SoluSoluççãoão hipotônicahipotônica
S G5%S G5%
SG5%/SF0,9% (1/5 SG5%/SF0,9% (1/5 --4/5)4/5)
HyponatremiaHyponatremia
Edema cerebralEdema cerebral
SIHAD / Hiponatremia
Inapropriado nível de ADH Exceso de água livre
HiponatremiaHiponatremia sintomsintomááticatica
Tipicamente
Prescrito por nós !
Hiponatremia sintomática
• Náusea, vomito
• Coma
• Convulsões
• Parada respiratória
• HIC
Hiponatremia sintomática
• Children may be at particular risk for developing hyponatremic encephalopathy
– Higher brain/skull ratio
– ? Impaired ability to regulate brain volume by osmoleextrusion
– Higher risk for hypoxemia
Moritz ML, Ayus JC. Disorders of water metabolism in children: hyponatremia and hypernatremia. Pediatr Rev 2002;23(11):371-80.
Hiponatremia sintomática
Os pacientes podem apresentar
uma rápida evolução dos
sintomas (edema cerebral)
Recommendation
• No routine use of hypotonic fluid in
hospitalized children
• 5% Dextrose/0.9% NaCl or 0.9% NaCl
• Does not apply to
– Premies and neonates
– High risk for fluid overload
– Ongoing free water losses