Beat the silent dehydration in fever

What is often overlooked in managing fever is the status of hydration and the presence of subclinical and overt dehydration when the body loses not only water but also essential electrolytes like sodium, potassium, calcium, and magnesium, writes Dr B Ravinder Reddy.

Fever is a common symptom in India. The common infections in which fever is seen include malaria, dengue, typhoid, chikungunya, respiratory infections, urinary tract infections, and other viral fevers.

Fever can also be accompanied by other symptoms like headache, vomiting, and general weakness. What is often overlooked in managing fever is the status of hydration and the presence of sub-clinical and overt dehydration.

Dehydration signifies a depletion of body fluids due to either excessive losses, reduced intake, or both. All types of lost fluid contain electrolytes in varying quantities, so fluid loss is always accompanied by some degree of electrolyte loss.

This is referred to as silent dehydration, as one can miss it due to a lack of awareness. Silent dehydration is a widespread concern globally, and fever may lead to dehydration.

Fever, when associated with increased sweating, leads to the loss of fluids and electrolytes, which can cause dehydration. The body loses not only water but also essential electrolytes like sodium, potassium, calcium, and magnesium.

Electrolytes are minerals that have a natural positive or negative electrical charge when dissolved in water. Each degree Celsius rise in temperature above 39°C (102 °F) in adults can lead to a 25 per cent increase in fluid losses via sweating and breathing. Nearly 1000 ml of fluid may be lost in 24 hours via these routes.

If there are bouts of vomiting, it can further add to fluid and electrolyte losses. Fever also leads to increased energy requirements. Every degree rise in body temperature in adults with fever can lead to a 10-11% increase in the consumption of energy.

This develops a situation with a high energy demand. Due to loss of appetite and altered taste, people with fever tend to consume less amount of fluids or food. This leads to a lesser intake of fluids, electrolytes, and energy, which may impact or delay recovery from fever.

Effects of dehydration

In a knowledge, attitude, and practices survey conducted with 494 Indian physicians, it was found that these fluids, electrolytes, and energy deficits in fever have a high impact on recovery. The patient may continue to feel weak and have protein losses from muscles, which may impact the ability of the body to fight infection.

Do oral electrolyte drinks help?

In the same study, it was found that 87 per cent of physicians agreed that fluids, electrolytes, and energy supplementation ought to be given to patients with fever as adjuvants, which can help improve the speed of recovery.

The Indian Medical Association suggests maintaining sufficient oral hydration during a fever to prevent dehydration. An international society, the American Society of Parenteral & Enteral Nutrition (ASPEN), recommends consuming liquids to replace the body’s fluid losses. It also emphasises the consumption of energy so that proteins from muscles are spared, protecting the muscle from breakdown.

While fluids and electrolytes can be replenished by the standard WHO ORS (World Health Organisation Oral Rehydration Solutions), they are best suited mainly for diarrhoeal conditions as ORS may not usually meet the energy goals in non-diarrhoeal conditions due to its low sugar content. Additionally, the strong salty taste of ORS makes it unpalatable which can affect adherence. 

The addition of energy (glucose) to fluid and electrolyte drinks helps address the energy needs and also helps in improving palatability and thus patient adherence. Certain ready-to-serve electrolyte drinks may also contain additional electrolytes or ingredients like magnesium, which can support muscle function.

To recover faster from fever, these deficits need to be addressed promptly with appropriate fluids and electrolytes. It would be advisable to consult your doctor if you have a high fever or signs or symptoms of dehydration like a dry tongue, dark-coloured urine, etc.

(The author is a Hyderabad-based senior gastrointestinal & general surgeon.)