Paediatric Anaesthesia 2000 10: 110–115

Correspondence

2 Rippe JM, Irwin RS, Fink MP et al. Intensive Care Medicine, 3rdThe management of extremeedn. Little Brown, 1996: 960–964.hypernatraemia secondary to salt

3 Behrmann RE, Kliegman R. Nelson Textbook of Pediatrics, 15thpoisoning in an infant edn. Philadelphia: WB Saunders, 1996: 212, 217–218.

4 Kumar S, Berl T. Sodium. Lancet 1998 352: 220–228.SIR—I would like to comment on the case report of the

5-week-old infant with severe hypernatraemia (1). The

outcome was excellent considering the difficulty of the

case but I feel that the authors did not stress enough the Author’s replyuse of isotonic solutions in the treatment of hypernatraemia.

The authors advocate the use of a more isotonic saline SIR—We thank Dr Ross for his interest in our case report. Dr

solution for initial therapy—why not use 0.9% saline? This Ross raised an important question concerning the optimal

still creates the hazard of a steep osmotic gradient between intravenous therapy when dealing with a patient

brain cells and extracellular compartments but much less presenting with extreme hypernatraemia. He suggests that

than other hypotonic solutions. The infant was dehydrated; the use of 0.9% saline could be more appropriate than a

this was presumably secondary to decreased water intake hypotonic solution, as used in our case report, creating

over the days preceding admission, with perhaps a lower osmolar gradient between intracellular and

additional salt and water loss through the kidneys induced extracellular spaces. This flattest gradient could be less

by a drop in aldosterone (2). Hypovolaemic hyper- detrimental for the brain, whereas the kidneys excrete the

natraemia is certainly easier to treat encouraging the use sodium load. Some points need to be discussed.

of 0.9% saline. Our patient had severe hypernatraemia due to the

Nevertheless, this was not primarily a case of water association of massive salt intake (improper formula

deficit and thus the aim of therapy is maintenance of preparations) and decrease of water intake (probably

hydration with solutions that create the flattest osmolar secondary to the unpleasant taste of the bottle’s content).

gradient whilst the kidneys excrete the huge sodium The association of these two mechanisms for creating

load (as this infant was doing very successfully). Over hypernatraemia, led us to follow current recommendations

time, as the serum sodium returns to approximately concerning the management of hypertonic dehydration,

150–160 mmol·l−1, compensatory brain idiogenic osmoles i.e. the use of a hypotonic solute with correction of the

become less influential and normal maintenance solutions water deficit over a 48 h period (1). With this regimen,

can be used. In this case, perhaps because the urine sodium despite complications that occurred during the treatment,

excretion halved in 24 h, this slowed the fall in serum final outcome with a follow-up of 16 months can be

sodium and allowed the use of hypotonic solutions. considered good (2).

Standard texts and reviews advocate the use of hypotonic The child was able to excrete the sodium load with the

solutions with removal of sodium either with diuretic use large urine sodium output tending to reduce serum sodium

or peritoneal dialysis (2–4); centres such as Toronto do not without other intervention. Whether infusion during the

recommend the use of hypotonic solutions in the critically initial phase with isotonic saline could permit a more

ill hypernatraemic child. Bohn DJ, personal communica- progressive decrease of serum sodium is likely but

tion (5). the expected better outcome remains speculative. At

This is a controversial area and faced with just such a presentation, the child had pulmonary oedema and renal

child, the guidance is confused. Use of iso-osmotic sodium failure [glomerular filtration rate (GRF) at 27 ml·min−1·

solutions with frequent measurement seems the most 1. 73 m−2]. Furthermore, we suspected tubular impairment

physiological therapy in the initial phase. as maximal urine concentration was 600 mosm·kg−1 H2O.

OLIVER ROSS A rapid calculation raised the risk of an insufficient negative

Department of Anaesthesia osmole ratio to achieve the goal of decreasing plasma

St George’s Hospital Trust osmolality (by 21 mosm·l−1 every 12 h) with the use of

Blackshaw Road NaCl 0.9% infusion. This could be detrimental in face of

London SW17 OQT pulmonary oedema. So, we used a hypotonic solute in

order to achieve a correct negative osmole ratio in the first

References 12 h interval, and then we adapted net fluid and osmole

input as GFR and tubular function improved.1 Paut O, Andre N, Fabre P et al. The management of extremeBased on the literature, the physician’s choice for treatinghypernatraemia secondary to salt poisoning in an infant. Paed

Anaesth 1999; 9: 171–174. hypernatraemia from exogenous salt administration is most

2000 Blackwell Science Ltd110

CORRESPONDENCE 111

often a hypotonic solution. In a review, Modler and Hurley Referencesfound 20 cases of hypernatraemia secondary to salt

1 Kallen RJ. The management of diarrheal dehydration in infantspoisoning in children. While the authors of the reportedusing parenteral fluids. Pediatr Clin North Am 1990; 37: 265–287.cases gave little information of details of therapy used,

2 Paut O, Andre N, Fabre P et al. The management of extremeinteresting data were given: a better survival rate was

hypernatraemia secondary to salt poisoning in an infant. Pediatrprovided with i.v. therapy (9/11) vs peritoneal dialysis (4/ Anaesth 1999; 9: 171–174.7) but mean initial sodium concentrations were higher in 3 Modler KG, Hurley DL. Fatal hypernatremia from exogenous

salt intake: report of a case and review of the literature. Mayothe dialysis group (215 vs 182 mmol·l−1), making the effectClin Proc 1990; 65: 1587–1594.of dialysis on survival rate unclear. Among the children

4 Conley SB. Hypernatremia. Pediatr Clin North Am 1990; 37:treated with fluids, two out of three children treated with365–372.

0.9% NaCl survived, while three of three children treated5 Roscelli JD, Yu CE, Southgate WM. Management of salt

with hypotonic fluids survived (1 child treated with 0.45%poisoning in an extremely low birth weight infant. Pediatr

NaCl and two children treated with 0.2% NaCl) (3). Other Nephrol 1994; 8: 172–174.authors recommend the use of hypotonic fluids in 6 Oh MS, Carroll HJ. Disorders of sodium metabolism:

hypernatremia and hyponatremia. Crit Care Med 1992; 20: 94–103.hypernatraemia, with the aim of bringing serum sodium

concentration to normal and to restore normal hydra-

tion (4–6). It seems currently difficult to define whether anUnilateral pulmonary cystic enlargementisotonic solution is a better choice than a hypotonic solution

in a newborn: remember the one-sidedin the management of such extreme hypernatraemia

secondary to salt intake. Thus recommendation is only blind intubationpresumptive, while of great interest.

SIR—A 5-day-old, 2.7 kg female infant, born at 40 weeksIn view of Dr Ross’s opinion, we would like to reiterate

of gestation, presented with tachypnoea and right-sidedsome guidelines for the treatment of extreme hyper-

cardiac sounds and was referred to the Japanese Red Crossnatraemia.

Nagoya First Hospital from an obstetric clinic. Physical(1) When hypernatraemia is associated with haemo-

examination revealed a heart rate of 196.min−1, adynamic alteration due to volume depletion, the initial

respiratory rate of 54.min–1, and sternal retractions. Onsolution for volume expansion should be isotonic saline

auscultation, left side breath sounds were decreased.(6). In this case, the aim is restoration of plasma volume

Findings of arterial blood gas analysis at FIO2 0.21 werepromptly without rapid reduction of serum sodium.

pH 7.45, PaCO2 4.5 kPa (34 mmHg), PaO2 7.0 kPa(2) When acute oliguric renal failure is present or when

(53 mmHg), and base excess –0.6. Chest X-rays (Figure 1)the hypernatraemia has an acute onset (<12 h) dialysis is

showed multiple cystic regions and hyperaeration of theuseful for salt removal. The role of dialysis in other

left upper lobe with a mediastinal shift to the right.indications is controversial.

Computed tomography (CT) (Figure 2) confirmed the(3) If diuresis is preserved, an intravenous infusion is

radiographic findings. Congenital cystic adenomatoidadministered. The nature of the initial solute is somewhat

malformation (CCAM) was diagnosed. Data from routinecontroversial. While some authors recommend the use of

haematological and biochemical evaluations were withinhypotonic solutions (0.45% saline), others recommend the

normal limits. Echocardiography ruled out any congenitaluse of isotonic saline for decreasing the osmolar gradient

heart disease. At 9 days of age, she weighed 3.2 kg andbetween extracellular compartment and brain, that could

was scheduled for left upper lobectomy. We planned torepresent the safest theoretical approach.

maintain spontaneous respiration until thoracotomy and(4) Whatever the choice of solution infused, it is of critical

resection of the involved lobe because positive pressureimportance to monitor frequently urine and plasma sodium

ventilation might further distend the left upper lobe.concentrations to adapt the intravenous fluid therapy. A

The infant was not given premedication and was calmnegative sodium balance is required and the endpoint

in the operating room. She came with i.v. catheter andis a decrease of plasma sodium of 15 mmol·l−1·day−1.

atropine 0.04 mg i.v. was given. Induction of anaesthesiaIn conclusion, there are limited data concerning the

was with sevoflurane and oxygen using a mask, themanagement of severe hypernatraemia. We encourage

sevoflurane concentration being increased 0.5% every threephysicians dealing with such cases with isotonic fluids to

to five breaths. As spontaneous respiration weakened, thepublish their experience for a better knowledge of the

oxygen saturation (SpO2) gradually decreased. Althoughoptimal fluid therapy in hypernatraemic salt poisoning.

gentle assisted ventilation was started, this decreaseOLIVIER PAUT

continued and when it reached 70%, suxamethonium 5 mgDepartement d’Anesthesie–Reanimation Pediatrique

i.v. was administered. tracheal intubation was easilyCentre Hospitalier Universitaire de La Timone

achieved, but the SpO2 continued to drop to 42%. DuringBd Jean Moulin

this course, breath sounds from the right lung were13385 Marseille cedex 5, France

continuously monitored with a precordial stethoscope, but

2000 Blackwell Science Ltd, Paediatric Anaesthesia, 10, 110–115