Weight loss, serum sodium concentration and residual symptoms in patients with hypernatremic dehydration caused by insufficient breastfeeding
Breuning-Boers, J.M.; van Dommelen, P.; van Wouwe, J.P.; Verkerk, P.H.
Nederlands Tijdschrift Voor Geneeskunde 150(16): 904-908
2006
ISSN/ISBN: 0028-2162 PMID: 16686091 Document Number: 603179
A systematic literature search was carried out to determine the relationship between serum sodium concentration and weight loss as well as residual symptoms in newborns with hypernatraemic dehydration caused by insufficient breastfeeding. The review also investigated the sensitivity of the rule of thumb "if weight loss is less than 10%, the baby does not have hypernatraemic dehydration caused by insufficient breastfeeding". MEDLINE was searched using the terms "dehydration and breastfeeding" for case reports on patients with "hypernatraemic dehydration caused by insufficient breastfeeding". Reference lists from the articles retrieved were also searched. Articles published in 1970-2004 in Dutch, English, French and German were also included. All cases that the author diagnosed as "hypernatraemic dehydration caused by insufficient breastfeeding" were included. 47 articles were found, containing 128 relevant cases. Of these 9 had less than 10% weight loss. Therefore, the sensitivity of the 10% rule was 93%. A linear relationship was found between the degree of weight loss and serum sodium concentration (Pearson's correlation coefficient=0.7; P<0.001). For every 10% increase in weight loss, the serum sodium concentration increased by 16 mmol/litre (95% confidence interval:13-19). As the serum sodium concentration increased, the prevalence of residual symptoms increased. No residual symptoms were reported in patients with less than 10% weight loss. Results show that the rule of thumb had a high sensitivity, however, the specificity should be determined before the rule of thumb is implemented.