Caution over fluids advice in respiratory infection
Advice to drink extra fluids during acute respiratory infection may be flawed, according to researchers writing in last week’s BMJ (2004;328:499).
The Australian researchers proposed theoretical reasons why increased
fluid intake could cause harm. Increased antidiuretic hormone secretion
has been reported in lower respiratory tract infections, although it
was uncertain if this was mirrored in the upper respiratory tract. Giving
extra fluids might lead to hyponatraemia and fluid overload, they suggest.
They searched the literature but were unable to find any trials providing
definitive evidence that increased fluid caused harm. However, two prospective
prevalence studies had found hyponatraemia at rates of 31 per cent and
45 per cent in children with moderate to severe pneumonia, although associated
symptoms were not reported. Several case studies also showed hyponatraemia
in patients with respiratory infections.
The researchers call for randomised controlled trials to provide definitive
evidence. “Until we have this evidence, we should be cautious about
universally recommending increased fluids to patients, especially those
with infections of the lower respiratory tract,” they conclude. |
The
Pharmaceutical Journal