ViewpointIntravenous fluids for seriously ill children: time to reconsider
Section snippets
Impaired free-water excretion during severe infections
Antidiuresis during fever and sepsis has been known for over a century, especially in pneumonia and meningitis. Hippocrates' description of pneumonia included scanty and high-coloured urine. In a rhesus monkey model of pneumococcal sepsis, urine volume and free-water clearance decreased to 25% and 17% of baseline values, respectively, during the first 9 h of infection.9 When 0·45% saline, equal to 105% of urine output in controls, was intravenously infused into septic monkeys, their bodyweight
Hyponatraemia in severe infections
Hyponatraemia arises in between 20% and 45% of children with meningitis,11, 12 pneumonia,13 encephalitis,14 septicaemia,15 cerebral malaria,16, 17 and somewhat less often in those with bronchiolitis.10 The patho-physiological basis is not fully understood, but many factors could be active in the same patient (table 1). Dilution of extracellular fluid because of impaired free-water excretion and increased urinary sodium losses seem to be the main mechanisms. Other mechanisms, including shifts of
Antidiuretic hormone
High concentrations of antidiuretic hormone are seen in many acute febrile illnesses,22 and are traditionally described as inappropriate. When applied generally, this term indicates our incomplete understanding of the potency of different stimuli to antidiuretic hormone release and suppression (table 1). Hypovolaemia might be a more potent stimulus for secretion of antidiuretic hormone than hypo-osmolarity is to its suppression. In a retrospective study of 300 children with meningitis,
Adverse effects of hyponatraemia
In the peripheral circulation, sodium moves freely throughout the extracellular fluid; the hydrostatic pressure gradient and oncotic pressure (predominantly made up of plasma proteins) are responsible for preventing the movement of water out of the vasculature. Cerebral circulation is different. Endothelial tight junctions prevent free movement of sodium across the intact blood-brain barrier, and therefore effective osmolarity is the major determinant of water movement into the brain
Potential pitfalls
Use of an isotonic, rather than hypotonic, solution does not mean that progressive hyponatraemia would not take place, but that it is much less likely. Although use of high-sodium-containing solutions in children with meningitis in the first 24 h was not associated with development of hypernatraemia,6 during the later phases of illness there is a theoretical risk of hypernatraemia if isotonic saline is used. Diuresis and low urine osmolarity is a feature of the convalescent phase of childhood
Possible solution
We postulate that 0·9% saline (with 5% dextrose) at less than standard maintenance volumes results in a lower frequency of hyponatraemia, seizures, and adverse neurological events than do hypotonic solutions (0·18%-0·3% saline), in acutely unwell children with brain injury of any type (meningitis, encephalitis, cerebral malaria, febrile seizures); serum sodium less than 138 mmol/L;30 or severe infection associated with greatly impaired free-water excretion.
Ideal testing of this hypothesis would
References (33)
- et al.
Normalization of plasma arginine vasopressin concentrations when children with meningitis are given maintenance plus replacement fluid therapy
J Pediatr
(1990) - et al.
Severe hyponatraemic encephalopathy after pediatric surgery: report of seven cases and recommendations for management and prevention
Ann Fr Anesth Reanim
(2000) - et al.
Fever and sepsis during neutropenia are associated with expansion of extracellular and loss of intracellular water
Clin Nutr
(2000) - et al.
Fluid and ion redistribution in skeletal muscle in an animal sepsis model
J Pediatr Surg
(1990) - et al.
Risks of intravenous administration of hypotonic fluids for pediatric patients in ED and prehospital settings: lets remove the handle from the pump
Am J Emerg Med
(2000) Maintenance fluid therapy
Fever
- et al.
Fluid restriction does not improve the outcome of acute meningitis
Pediatr Infect Dis J
(1995) - et al.
Postoperative hyponatraernic encephalopathy: water intoxication
Aust NZ J Surg
(1998) Hyponatraemia, convulsions, respiratory arrest, and permanent brain damage after elective surgery in healthy women
N Engl J Med
(2002)
Hyponatraemia in the postoperative craniofacial pediatric patient population: a connection to cerebral salt wasting syndrome and management of the disorder
Plast Reconstr Surg
Depression of free water clearance during pneumococcal bacteraemia
Ann Surg
Water electrolyte homeostasis in acute bronchiolitis
Indian Pediatr
Initial fluid therapy for children with meningitis with consideration of the syndrome of inappropriate antidiuretic hormone
Clin Pediatr
Circulating sodium in acute meningitis
Am J Nephrol
Hyponatremia and the inappropriate ADH syndrome in pneumonia
Ann Trop Paediatr
Cited by (114)
Risks of severe hyponatremia in children receiving hypotonic fluids
2020, Archives de PediatrieCitation Excerpt :This might be explained by the empiricism of historical recommendations published roughly 60 years ago, favoring dextrose 5% in water (D5W) with low amounts of sodium (e.g., a quarter [NS/4] or half [NS/2] of normal saline [NS]) [1]. Furthermore, the syndrome of inappropriate secretion of anti-diuretic hormone (SIADH) often occurs in several diseases currently seen in children (e.g., acute gastroenteritis, viral bronchiolitis, encephalitis, meningitis; Table 1), which impairs the excretion of free water and favors the occurrence of hypotonic hyponatremia [2]. In the 2000s, two American pediatric nephrologists reported a series of children with severe hypotonic fluid-induced severe hyponatremia leading to severe neurological sequelae and death [3,4].
Fluid Management
2019, A Practice of Anesthesia for Infants and ChildrenFluid Management
2018, A Practice of Anesthesia for Infants and ChildrenMaintenance fluid practices in paediatric intensive care units in Australia and New Zealand
2017, Critical Care and Resuscitation