Advancements in Critical Care

Hypernatremia in a one-month-old baby – a case report

Seppo Ranta, MD, PhD
Department of Anesthesia and Intensive Care Medicine
Helsinki University Central Hospital
Hospital for Children and Adolescents
Helsinki, Finland

The article also available in PDF: 220KB

Introduction

Extreme hypernatremia is associated with marked morbidity and mortality. One pediatric case is described where the serum sodium at the admission was over 200 mmol/l.
Clinical information systems may provide assistance in the critical care process by making complex calculations easier, and by providing more easily comprehensible data for decision making. The following is a pediatric case which demonstrates these benefits.

Case

A 24-day old baby girl was admitted to the University Hospital because of extreme hypernatremic contraction. She was born at the gestational age of 40+3 weeks by a cesarean section because of a protracted delivery. The APGAR score was 9, and she weighed 3720 g. The mother and child were discharged from the maternity hospital three days after delivery without any abnormalities.

Three weeks after the birth, the mother phoned the well baby clinic because she thought that the baby had lost weight. A checkup was scheduled in two days time. When the baby arrived at the well baby clinic, at the age of 24 days, she was noted to be weak and cachexic. A high-pitched cry was noticed. At that time, the baby weighed 2355 g. Serum electrolytes were measured, and S-Na was noted to be over the upper measuring range (200 mmol/l) of the analyzer. Intravenous Ringer’s acetate was started, and the baby was immediately transferred to the University Children’s Hospital.

In the University Pediatric Intensive Care Unit (PICU), the intravascular contraction of 10% was estimated on clinical grounds . It was decided to correct the contraction over 24 hours with Ringer’s acetate supplemented with sodium. S-Na on arrival at the PICU was 191 mmol/l and S-osmolality 470 mOsm/kg. It was decided to correct the sodium and serum osmolality over five days (Figure 1). The baby’s basic fluids and nutrition were provided by intravenous glucose and an amino acid solution supplemented with electrolytes.

Hypercalcemia was also present, and therefore, no calcium was given to the child. Nephrocalcinosis was found in the ultrasound scan of the abdomen, echocardiography was normal, and the parathyroid gland area in the neck was normal on ultrasound. Thyroid function, serum cortisol, S-ACTH, and serum aldosterone concentrations were normal.

Oral feedings were started on day three after admittance to the PICU. A formula without calcium was used first, and after five days, breast milk was used.

After a week in the PICU, the baby was transferred to a general ward and discharged home after 17 days of treatment in the hospital. The only remaining abnormality was constant hypercalcemia and slightly increased secretion of calcium in the urine. Routine controls at the outpatient department of the Children’s Hospital were performed until eleven months after the hypernatremia episode. At that point, the growth and development of the girl was normal, no hypercalcemia was noted. In addition, the nephrocalcinosis had disappeared in the renal ultrasound.

Discussion

The causes of hypernatremia may be divided to extrarenal losses of water in excess of sodium (vomiting, diarrhea, sweating, dermal insensible losses), renal losses of water in excess of sodium (osmotic diuretics, dibetes insipidus), or administration of sodium in excess of water1.

The baby described was fed only with breast milk while at home, however, according to her mother, she did not feed well. The family was on several occasions discussed with by doctors and social workers, and deliberate use of concentrated feeding formulas or not giving feedings to the baby were denied. Therefore, the only remaining explanation for the hypernatremia was inadequate feeding of the child with consequent loss of water in excess of sodium.

Extreme hypernatremia and hyperosmolality are associated with high mortality and mortality1. In experimental animals, death from respiratory failure developed when serum osmolality reached 430 mOsm/kg2. However, the baby described here showed no signs of abnormality in the follow-up.

Treatment of complex fluid and electrolyte balance problems in pediatric patients requires complex calculations. The calculations are considerably easier with information systems providing adequate calculation tools. In addition, following the effect of treatment is easier using graphical trend displays.

References

1. Wood, EG, Lynch RE: Fluid and Electrolyte Balance, in: Fuhrman BP, Zimmerman JJ (eds.): Pediatric Critical Care, 2nd ed., Mosby, St.Louis, 1998.
2. Lockwood AH: Acute and chronic hyperosmolality. Effects on cerebral amino acids and energy metabolism. Arch Neurol. 32: 62-64, 1975

[Accepted for publication April 4, 2002]

Figure 1. The correction of hypernatremia and hyperosmolality over five days is shown (upper panel). The amount of sodium and potassium administered is shown in the lower panel. Hypercalcemia is also depicted in the lower panel.

Figure 2. Panel of laboratory values during treatment of hypernatremia. Upper left panel: hemoglobin (g/l), trombocyte (x 109), leukocyte (x 109) ja hematocrit values. Upper right panel: arterial blood gas values (kPa; Base Excess mmol/l). Lower left panel: serum sodium, potassium and ionized calcium levels. (mmol/l). Lower right panel: blood glucose and lactate concentrations (mmol/l).

Last updated: 1 November 2003Created
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