Fever increases perspiration due to high respiratory rate, mucus secretion, and excretion, which leads to rapid loss of fluids and electrolytes from the body. This renders our cells, muscles and functional systems weak. Loss of appetite and weakness during fever further reduces the intake of food and fluids, catalysing dehydration among patients. Studies find that for each degree rise in body temperature above 98.6 degrees an adult with fever loses nearly 2.5 ml body fluid per kilogram body weight per day as ‘insensible losses’. In fact, ASPEN studies denote that an adult with 102 degrees Fahrenheit fever sheds 30 ounces (0.9 L) of fluid every 24 hours, in addition to 3 ounces (88.7 ml) lost through coughing and breathing.
This worsens dehydration and decelerates recuperation and recovery. It also leads to persistent hyperthermia and chills. If left untreated, dehydration can cause further damage to organs, skin, and muscles and may also reduce the ability of the body to fight against infections. Thus, it is of utmost importance that while tending to fever, we must take extra care to prevent dehydration.
Caring for dehydration during special fever
The common flu, caused by influenza infection, is a frequently seen cause for fever, recording about 10 million cases per year in India, although treatable. However, there are a number of other infections which accompany fever and illnesses that take additional time and effort to be cured. Such ‘special’ fevers augment the risk of severe dehydration in patients
For instance, dengue, a viral illness borne by the Aedes mosquito, is often characterized by high fever, vomiting, nausea, anorexia and diarrhoea, especially during its febrile phase of four to six days. These lead to major dehydration and weakness in patients. Furthermore, a number of dengue victims are found to suffer from leakage of blood plasma through their small blood vessels, causing fluids to escape the intravascular space and leading to dehydration and even shock. Electrolyte and acid-base imbalances are commonly seen in severe dengue – caused either due to the gastrointestinal losses or the use of hypotonic solutions for resuscitation. In such situations, rebalancing body fluid becomes critical, which is supported by studies linking fluid intake of more than five glasses in 24-hour durations to reduced risk of the fever worsening and the subsequent need for hospitalization.
Parallels can be drawn among patients with typhoid, which is caused by Salmonella bacteria infection. Typhoid also leads to excessive loss of body fluids through vomiting, diarrhea and Persistent high fever, with imminent dehydration. This is why oral or IV rehydration, along with proper nutrition and medication, becomes key to fighting typhoid.
Such cases bear the risk of excessive fluid and electrolyte losses at life-threatening levels. Dehydration by more than 25% leads to hypovolemic shock, which can cause major complications such as gastrointestinal bleeding, disseminated intravascular coagulopathy, and multiorgan failure. Therefore, it is crucial to examine the level of dehydration in patients and choose a course of action that emphasizes the quickest route to recovery.
Fever and dehydration in the young and elders: Focus on pediatrics and geriatrics
While dehydration due to fever can affect patients of all ages, elders and children are the most vulnerable to its ill effects. Due to age-based physical conditioning, elders and children suffer from extended effects of dehydration.
Dehydration in infants and children: Infants and children are often treated for diarrhea and vomiting, caused by various infections. This makes them frequently vulnerable to dehydration. Having a higher physical surface-to-volume area causes them to lose a higher proportion of their body fluids from a high fever and illnesses. Toddlers often can’t express when they’re thirsty, and thus, are prone to dehydration if not attended to properly.
One of the more common risks of dehydration comes with malaria. Every year, around 200 million people worldwide contract malaria, and India reports 3% of the global cases. Almost 20% of these victims are children. Children under five years do not acquire the necessary immunity to fight infections, and hence, are quick victims to the ill effects of malarial fever. Cerebral malaria and anaemia are more serious risks in children. In such situations, fluid resuscitation and electrolyte balance is generally considered to be a cornerstone of treatment.
Children must be offered plenty of fluids as oral hydration, along with nutrition, to prevent the loss of body water and reduce the risk of fever. Pediatricians, thus, advise parents to build frequent fluid intake habits among their children.
Dehydration in elders: The European Society for Clinical Nutrition and Metabolism (ESPEN) 2019 guidelines suggest that screening geriatric patients for dehydration is key in the treatment of fevers. With age, our body’s fluid reserve diminishes, our ability to conserve water contracts and sense of thirst reduces. These conditions, further compounded by co-morbidities like diabetes, make elders naturally vulnerable to fluid and electrolyte loss. Fever and other ailments further complicate the condition. In fact, one out of every three elders taken to the emergency department are found to be dehydrated.
Water intake suggestions
For a healthy male, the body’s total water requirement is approximately 4.2 L per day. The ESPEN guidelines advise older women to consume at least 1.6 L of drinks each day, while men should consume at least 2.0 L of drinks each day, For children, the Children’s Hospital of Orange County (CHOC) advises water consumption in proportion to their age, where five to seven year old children are suggested to be given between 40 ounces (1.2 litres) and 56 ounces (1.7 litres) of water per day, while children above eight years should consume up to 64 ounces ( about 2 litres).
A habit of regular hydration is crucial. It is advisable to consume an ounce of water (29.6 ml) for each kilogram of body weight. When suffering from fever, the focus should be on minimizing the insensible losses of fluid. Proper oral hydration can help reduce insensible losses and also prevent hospitalization. A person should intake roughly 20 ml of fluid for each kilogram body weight per day. This ensures replacing lost fluid in the body, reduces the viscosity of secreted mucus to prevent respiratory infections, and replenishes the organs and muscles.
Alongside recommending all these hydration best practices, clinicians should drive added focus toward rehydration of children and elders, as they form a large part of the population. In this manner, they can enable a holistically healthy and immune community.