Conceitos básicos para prescrição de soluções hidroeletroliticas endovenosas para crianças

1. Terapêutica hidro-eletrolítico
em pediatria
Antonio Souto
acasouto@bol.com.br
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

2. Conceitos básicos
Fisiologia
Bioquímica das soluções

3. 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.

6. 10

7. Serum Osmolality
• Normal: 275 – 295 mOsm/L
Isotonic
• < 275 mOsm/L = Hypotonic
• > 295 mOsm/L = Hypertonic

11. 1 Litro de SF 0.9%
Total body water
ECF=1 liter ICF=0
Interstitial=3/4 of
ECF=750ml
Intravascular
=1/4 ECF=250 ml

12. 1 litro de SG 5%
Total body water=1 liter
ECF=1/3 = 300ml ICF=2/3 = 700ml
Intravascular
=1/4 of ECF~75ml

15. Indicação de suporte hidro-eletrolítico
endovenoso
•Impossibilidade de uso da VO
•Tratamento de distúrbios hidro-eletrolíticos
•Necessidade do uso de medicamentos EV

16. Príncipios para prescrição do suporte hidro-
eletrolítico endovenoso
•Quanto volume ?
•Qual solução?
•Doença de base
•Condição hidro-eletrolítica
•Idade
•Peso

17. Quanto volume?
• Condição hidro-eletrolítica (reposição)
• Necessidades basais (perdas fisiológicas)
• Perdas anormais

18. 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.

19. Quanto volume?
Holliday MA, Segar WE. The maintenance need for
water in parenteral fluid therapy. Pediatrics
1957;19(5):823-32.

20. NATURE CLINICAL PRACTICE NEPHROLOGY JULY 2007 VOL 3 NO 7
The main factor contributing to the
development of hospital acquired
hyponatremia is routine use of hypotonic
fluids
Excess arginine vasopressin (ADH)

21. Patients at greatest risk of developing
hyponatremic encephalopathy
following hypotonic fluid
administration
children,
postoperative patients,
brain injury or infection,
pulmonary disease or hypoxemia.

22. 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.

23. 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

24. 25 of 27 acutely ill children with hyponatremia had elevated
plasma 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 better
than half normal saline for rehydration of children with gastroenteritis. Presented
as poster #866 at the Pediatric Academic Society’s annual meeting,
Seattle, Wash 2003.

25. Prospective study
Children with meningitis and elevated ADH
Isotonic 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

26. 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 ADH
Keil LC. Release of vasopressin by angiotensin II. Endocrinology
1975;96(4):1063-5.

27. Liberadores não-osmóticos de
ADH
• Doenças pulmonares
• Ventilação mecânica
• Distúrbios neurológicos meningite, encefalite,
tumores, trauma
Kaplan SL, Feigin RD. The syndrome of inappropriate secretion of
antidiuretic hormone in children with bacterial meningitis. J Pediatr
1978;92(5):758-61.

28. 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)

29. gica
roló
a neu
Pos Doenç
tope
ra t ó Naus
ri o ea, v
omit
o
Dr
og
as
Qual criança ia
i po volem Bron
internada não
H
Do
en
ça
sR
quio
lite
es
dor apresenta risco pi r
ato
r ia
s
o
tensã
de SIADH?
Hipo m edo
mi a
e
Est oglic
re s Hip
se

30. Apropriada secreção de H AD Inapropriada secreção de H AD
Retenção renal de água
Solução hipotônica
S G5%
SG5%/SF0,9% (1/5 -4/5)
Edema cerebral
Hyponatremia

31. SIHAD / Hiponatremia
Inapropriado nível de ADH Exceso de água livre
Tipicamente
Hiponatremia sintomática Prescrito por nós !

32. Hiponatremia sintomática
• Náusea, vomito
• Coma
• Convulsões
• Parada respiratória
• HIC

33. Hiponatremia sintomática
• Children may be at particular risk for developing
hyponatremic encephalopathy
– Higher brain/skull ratio
– ? Impaired ability to regulate brain volume by osmole
extrusion
– Higher risk for hypoxemia
Moritz ML, Ayus JC. Disorders of water metabolism in children:
hyponatremia and hypernatremia. Pediatr Rev 2002;23(11):371-80.

34. Hiponatremia sintomática
Os pacientes podem apresentar
uma rápida evolução dos
sintomas (edema cerebral)

40. 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