- Fluid and electrolyte therapy in common neonatal conditions in neonates.

Fluid and electrolyte therapy in common neonatal conditions in neonates.

1. Congestive heart failure: infants usually require fluid restriction (-30 ml/kg).

2. PDA: restrict fluid administration. This is especially important when indomethacin is
prescribed to treat PDA (as indomethacin can decrease urine output).

3. RDS: infants with RDS need appropriate fluid therapy because:

• Excessive fluid administration can lead to hyponatremia, volume overload,
• worsening the pulmonary condition and increasing the risk of developing BPD.
• Inadequate fluid administration leads to hypernatremia and dehydration.
• It has been observed that clinical improvement in infants with RDS is accompanied by an increase in urine volume that occurs on the 2nd and 3rd days of life.
• Despite the observed association between diuresis and improving lung function, there are no data to support routine administration of diuretics to the preterm infant for treatment of RDS.
• Infants with RDS and other pulmonary disorders may have increased secretion of antidiuretic hormone, especially if they develop pneumothorax , When carefully used, positive-pressure ventilation, either conventional or high frequency, does not impair diuresis or cause water retention .
• RDS commonly is associated with a combined respiratory and metabolic acidosis resulting from hypercapnia and mild lactic acidemia. If the acidosis is primarily metabolic, the underlying cause should be identified and corrected.

4. BPD: diuretics (e.g., furosemide) are often prescribed in these infants to treat

pulmonary edema, which can lead to electrolyte disturbances.

5. Phototherapy: An additional 10-20ml/kg/day is allowed in the daily fluid intake if the infant is treated with phototherapy.

6. PERSISTENT PULMONARY HYPERTENSION

• Fluid management in the in ant with persistent pulmonary hypertension is crucial, because hypovolemia can exaggerate right-to-le t shunting, leading to worsening disease.
• Once euvolemia is achieved there is no additional benefit to repeated volume boluses.
• Hypoglycemia and hypocalcemia should be avoided, because these states can also exacerbate pulmonary hypertension.

7. Perinatal asphyxia:

• These infants are prone to acute tubular necrosis and significant oliguria, and the CNS injury may produce syndrome of inappropriate release of antidiuretic hormone (SIADH).
• During the first 48-72 hours of life, the water intake for asphyxiated infants should be limited to IWL plus urine output or restriction of 30% to allow for some physiologic contraction of the ECW volume.

8. NECROTIZING ENTEROCOLITIS

• Necrotizing enterocolitis often results in a shock like state in the infant.
• Capillary integrity and lymphatic drainage is often compromised, leading to fluid accumulation in the interstitium and diffuse bowel or other tissue edema (the “third space”).
• As effective circulating volume is diminished, antidiuretic hormone is released and the rennin angiotensinaldosterone system is activated, leading to sodium and free water retention.
• Management is aimed at maintaining adequate intravascular volume and perfusion with the use of volume expanders, vasopressors, and/ or inotropes.
• Corticosteroids may also be useful to mitigate the effects of capillary leak.
• Discontinue all potassium-containing fluids because the combination of oliguria and bowel necrosis can quickly result in hyperkalemia.

9. Central Nervous System Injury

• Infants with brain injury from other causes, such as intracranial hemorrhage or CNS infection, may also have oliguria and water retention because of inappropriately increased secretion of antidiuretic hormone.
• 10. Abdominal Wall Defects
• Infants born with abdominal wall defects (gastroschisis or omphalocele) have increased IWL from the exposed viscera and require extra water prior to surgical repair. This is especially true of infants with gastroschisis because there is no membrane covering the exposed organs. Once the abdominal wall has been closed, evaporative water loss is no longer increased, although there may still be abnormal loss of water into the peritoneal cavity or interstitial fluid compartment.

11. Renal failure :

• Fluids restricted to IWL and urinary loss.
• IWL replaced By glucose 10% or Glucose5 %
• Urinary loss is replaced By N/5.

12. Diarrhea:-

• The principles of parenteral fluid therapy of diarrheal dehydration in the newborn infant are similar to those applied to older infants and children.
• Because of their limited renal concentrating ability, newborn infants are quicker to develop severe dehydration, hypovolemia, and cardiovascular collapse.
• Therefore, rapid establishment of intravenous access for vascular expansion is of the utmost importance in neonates with moderate-to-severe dehydration from diarrhea.
• After stabilization, fluid and electrolyte deficits should be estimated as described. Water and electrolytes should be given to correct established deficits, meet maintenance requirements, and counteract ongoing losses.

13. Postoperative abdominal surgery:

• Fluid requirements may be twice or three times that noted above.
• The more extensive the procedure the greater the needs!
• These infants may require 125-150 ml/kg/day immediately postoperative with subsequent increases as determined by blood pressure measurements and urine output.
• Isotonic saline also may be required because of third spacing of fluid into tissues and other spaces, e.g., the bowel lumen.

14. Shock and Edema

• In the uncompensated phase of shock, blood pressure is low; cardiac output may be low, normal, or high; effective circulating blood volume is usually decreased; transcapillary hydrostatic pressure is elevated; and capillary integrity and lymphatic drainage are impaired, resulting in edema formation and increased interstitial compliance.
• The changes in the effective circulating blood volume also trigger the release of antidiuretic hormones, including catecholamines, renin-angiotensin-aldosterone, and vasopressin, resulting in the retention of sodium and free water.
• The specific cause of shock (e.g., infection, asphyxia, myocardial insufficiency, hypovolemia) may independently contribute to this chain of events, further compromising fluid and electrolyte balance. In affected infants, treatment is directed at normalizing tissue perfusion and oxygen delivery by restoring effective intravascular volume, cardiac output, and renal function with the use of vasopressor and inotropic support, as well as with the judicious use of volume expanders while monitoring blood pressure, cardiac output, and changes in organ blood flow
• In shock refractory to these therapies, early initiation of low-dose glucocorticoid and mineralocorticoid replacement may help to break the vicious cycle by improving capillary integrity and thus effective circulating blood volume, and by potentiating the cardiovascular response to vasopressors and inotropic agents.

15. Fluid restriction

• There has been a lot of interest in the amount of fluid therapy and outcome of preterm neonates in terms of mortality and morbidity. The Cochrane meta-analysis on this topic could identify four eligible studies13. Their findings state that, although restricted fluid therapy may lead to greater weight loss and dehydration, it is associated with a decreased incidence of death, PDA and NEC. There also seems to be a beneficial effect of restricted fluid therapy on the incidence of BPD. The volume of fluids used in the restricted groups differs from the above-described fluid therapy by 20-50 ml/kg/day in the initial 3-4 days. Based on their meta-analysis, the investigators had concluded that fluid therapy needs to be balanced enough to meet the normal physiological needs without allowing significant dehydration.