Hydration in severe acute asthma

A tribute to Paul PotterPaul Potter was appointed as the first paediatric allergy registrar in my Department of Paediatric Allergy at the Red Cross War Memorial Children’s Hospital in 1982. He immediately showed a great interest in all aspects of paediatric allergy and this interest was accompanied by an enormous capacity for hard work and boundless enthusiasm. In this same year he also managed to find time to obtain a BSc (Hons) degree in Immunology (with distinction). Paul conducted a most important study on the fluid requirements of children presenting with severe acute asthma. At the time IV fluid supplementation was considered to be an important part of the management of children with severe acute asthma, but there was considerable debate about the correct volume of fluid to be given. One approach based on adult studies had shown considerable dehydration in these patients and recommended that double the maintenance volume of fluid was to be given. The liberal correction of fluid deficits was also thought to help to mobilise any mucus plugs blocking the airways of these patients. A second approach assumed that dehydration was not an important feature and that the over-correction of fluid deficits in children with severe acute asthma was likely to be harmful. Paul’s study showed that mild dehydration was common in children with severe acute asthma and that fluid given at a rate of 50 mL/kg/24 hours was safe and appropriate.This study significantly changed our approach to the use of IV fluids in treating children presenting with severe acute asthma. His article, published in a prestigious international paediatric journal, had a considerable impact on the management of fluid requirements of children with acute severe asthma in many countries. Even more amazing is that this important article was to be the first of more than 370 articles that Paul would go on to write and publish. Of these, 130 articles appeared in international peer- reviewed journals, including six citation classics.Twenty children were studied during severe attacks of acute asthma to determine how dehydrated they were on admission to hospital. Mean body weight on admission was 97.8% of their reference stable weight seven to ten days after the attack and in only three children was it less than 95% of the stable weight. Bedside assessment of dehydration was unreliable. The mean packed cell volume was significantly higher on admission than 7–10 days later (0.44 compared with 0.42, differenc