Dehydration is a common phenomenon in those suffering from infectious diseases, particularly if the diseases cause vomiting and/or diarrhea. We are all familiar with having the “stomach flu,” “traveler’s diarrhea,” or food poisoning. However, severe infections of all sorts can cause profound illness, debilitation, and fluid losses. In many developing countries, very large numbers of small children are afflicted with non-gastrointestinal infectious diseases that rapidly cause relatively large fluid losses, and therefore profound, life-threatening dehydration, which is manifested in part by dangerously low blood pressure and subsequent failure to deliver precious liquid, nutrients and oxygen to the tissues of the body. This is called “shock.”
The following discussion is cutting edge information, but not simplistic or necessarily easy to understand or apply. However, I have learned that my readers are often volunteers in settings where intensive care medicine must be applied, and want to read more than simple approaches to therapy. So, I am going to do my best to interpret for you what has recently been published in the New England Journal of Medicine in an article entitled “Mortality after Fluid Bolus in African Children with Severe Infection” (N Engl J Med 2011; 364:2483-95) written by Kathryn Maitland and her colleagues.
The focus of their investigation was the role of fluid resuscitation in the treatment of children with fever, shock, and life-threatening infections in resource-limited settings. Of note is the fact that the study excluded children with malnutrition and gastroenteritis (inflammation of the gastrointestinal tract, which would include infectious diarrhea). What would be a disease state that could be included in this study? Malaria is a good example. In this study, children with severe infectious diseases associated with “impaired perfusion” (i.e., shock or impending shock) were randomized to receive either rapid fluid boluses (large volumes of fluid calculated by body weight to rapidly restore volume status) or to receive no fluid boluses. All children received appropriate antibiotics, intravenous “maintenance” fluids (to approximate daily needs), and supportive care.
The results were enlightening. The children treated with fluid boluses had a significantly increased mortality at 48 hours after the initiation of treatment over the group that did not receive fluid boluses. Particularly interesting was the fact that beyond the numbers indicating increased mortality, there was not apparent physiological explanation for what was observed. In other words, the children who received fluid boluses did not appear to have an increased incidence of excess fluid in the lungs or brain.
So, what might have caused this effect? Based on what we know about the pathophysiology of shock, the authors speculated. Perhaps in a shock state, certain blood vessels constrict to shift blood flow to vital organs, and this situation might be negated by rapidly infusing fluid. Another possibility is that there were subtle effects on organs such as the lungs, brain, or heart that could not be detected. It is also possible that improving blood pressure and blood flow too quickly could cause its own set of problems, which is an area of active investigation in medicine under the category of “reperfusion injury.”
For the field practitioner of medicine, what conclusions can be drawn? For medical professionals, this study calls into question the practice of rapid intravenous administration of fluid to attain a certain blood pressure number, which might not equate with physiological treatment success. For laypersons, who do not use intravenous fluid, it is life as usual, because oral rehydration is all that is available to treat a situation like this. For everyone, since gastroenteritis and malnutrition were excluded, no conclusions can be drawn in these situations. If there is ongoing fluid loss associated with a gastrointestinal infection (e.g., cholera), until further notice, one needs to keep up with fluids to avoid getting so far behind in a resuscitation that one cannot catch up. Malnutrition may be a separate entity altogether, so it is difficult to predict what might be the outcome of fluid bolus therapy in this situation.
This post, Study Investigates The Role Of Fluid Resuscitation In Treatment Of Life-Threatening Infections, was originally published on Healthine.com by Paul Auerbach, M.D..