OF FEVER AND HYPERTHERMIA

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OF FEVER AND HYPERTHERMIA
OF FEVER AND HYPERTHERMIA

Any discussion about treating fever must necessarily begin with a discussion of the response of the human physiological system to a whole range of temperatures of the human body above what is considered normal i.e. 36.5–37 °C (97.7-98.6 °F) degrees. This implies that a temperature above the upper limit is considered as fever.

Most fevers are caused by infectious disease and can be lowered, if desired, or considered necessary by a physician with antipyretic medications- I am not considering elevation of temperature due to heat stroke.

Hyperthermia refers to a group of heat-related conditions characterized by an abnormally high body temperature.

The zone of Hyperthermia begins at about 40°C – 104° F. Though not life- threatening, it requires immediate treatment. The common symptoms include headache, confusion, and fatigue. If sweating has resulted in dehydration, then the affected person will have dry, red skin.

A temperature above 41 °C (105.8 °F) is considered as a medical emergency because it indicates that the patient has fully entered the zone of hyperthermia. The condition is characterised by fainting, vomiting, severe headache, dizziness, confusion, hallucinations, delirium, and drowsiness. There may also be palpitations and breathlessness. The occurrence of death varies between 5-20%.

At 42 °C (107.6 °F) the patient may turn pale or remains flushed and red. He may become comatose, be in severe delirium; vomiting, and convulsions can occur. The occurrence of death reaches 50%.

If the temperature reaches 43 °C (109.4 ° F) there would be serious brain damage, continuous convulsions, and shock. Cardio-respiratory collapse will most likely occur; 90% of people die at this temperature.

When the body temperature reaches 44 °C (111.2 °F) the occurrence of death reaches 99%. Only a handful of people have been known to survive up to 46.5 °C (115.7 °F) in recorded history e.g a
52-year-old man Willie Jones of Atlanta was admitted to a hospital in Atalanta on July 10, 1980, with heatstroke and a temperature of 115 degrees Fahrenheit. He spent 24 days in the hospital and survived. He holds the Guinness Book of World Record for highest recorded body temperature.

Markedly elevated or prolonged fever i.e. elevated temperature, above the upper limit 37° C or 98.6° F results in profound metabolic disturbances. Fever may also alter the metabolism and disposition of drugs used for the treatment of diverse diseases associated with fever.

In their treatment of diseases medical practitioners very often come across various suggestions or theories which sometimes are mutually contradictory. The approach to all reduction of high temperature or fever as it is known is a controversial subject. Till recently it was not clearly known if fever plays any beneficial role in the body mechanism though there is evidence to suggest that before the discovery of antibiotics, fever was employed with limited success as nonspecific therapy for some chronic infections.

One undesirable, and fairly widespread medical habit is a spontaneous reflex on the part of physicians to regard elevated temperature as an intrinsic part of a disease and thus an undesirable phenomenon to be combated as soon as it manifests itself in any ailment. This tendency is apparently rooted in the firm belief that a person’s temperature should be brought back to normal as speedily as possible. However, thanks to the work of two scientists in the United States, new evidence has come to light showing that the eagerness on the part of doctors to prescribe antipyretics to reduce the temperature can actually do more harm than good. In practice, such indiscriminate medication may well interfere with the bodys own defences which are often more effective than drugs. (There is another serious life-threatening side- effect called Reyes syndrome in children recovering from a viral infection such as chickenpox or flu or who have a metabolic disorder, if they’ve been taking aspirin. Early symptoms include diarrhoea, rapid breathing, vomiting and severe fatigue. Symptoms such as confusion, seizures and loss of consciousness need emergency treatment. There’s no specific treatment for Reye’s syndrome beyond supportive care and careful monitoring for complications.

It was Andrew Lwoff, a Nobel Laureate, who first questioned the principle that fever was an intrinsic part of a disease and thus a phenomenon that should be tackled aggressively as part of the treatment. Working at the Pasteur Institute in Paris, he discovered about five decades ago that poliomyelitis virus grows well in tissue-cultured cells at 35° C (95° F). Between 38.5 and 39° C (101.3 and 102.2° F) the release of new infectious virus particles falls down from 95 per cent at 35° C (95° F) to 2 per cent. What this means is that even a slight rise in temperature seems to reduce considerably the multiplication of polio viruses. The implication of this work was clear. While a substantially elevated temperature, i.e. above 41° C (105.8° F) is not only dangerous requiring urgent treatment, the indiscriminate use of aspirin and other antipyretic drugs to bring down moderate fever in influenza is unwise. Increased temperature may ironically be the bodys most potent means of thwarting or inhibiting and countering viral disease. Several research groups have also confirmed the findings of Professor Lwoff and found that his observations apply to other microbes as well. The American physiologists mentioned earlier have, for example, shown how fever acts against invading bacteria also. While Lwoff worked with tissue-cultures, the American scientists investigated fever in mammals. Their findings may well apply to human infections.

The subjects for the experimental study were New Zealand rabbits infected with pasteurella multocida—a bacterium related to the plague bacillus which is a common cause of disease in rabbits. The American scientists noted two related effects: as the temperature of the infected rabbits rose the amount of iron in their blood plasma fell. So they next studied cultured pasteurella multocida in an artificial- nutrient media at various temperatures and with different amounts of iron. The results were striking. At the normal temperature of healthy rabbits, the bacteria multiplied, irrespective of the concentration of iron. However, higher temperatures inhibited their growth.

Further studies by different scientists have revealed that the virulence of many disease-causing bacteria depends on their ability to secure adequate supplies of iron. Reduction of this intake in high fever may explain why a fever is an important positive force in the battle against infection.

The American researchers justifiably concluded that taking drugs to reduce fever may well impair the bodys own protective mechanism. While aspirin remains an excellent drug to combat pain, prescribing it indiscriminately to reduce fever, as many physicians do, may be a serious error as indicated above. In particular, in children with chickenpox, a physician

It would, in fact, be extraordinary if these findings are not applicable to humans, as they are to rabbits. Dr Lwoff and his colleagues found that when dogs infected with the vaccinia virus were given fever-reducing drugs, their chances of dying increased and mice suffering from viral encephalitis can be cured as easily by raising their temperature as by giving them massive injections of antibodies.

The tests made by the American scientists illustrated an effect involving nutrition. Some researchers have discovered that a crucial nutrient involved in the manufacture of influenza virus is unstable at temperatures reached through the disease itself. Others suggest that animal cells produce more interferon during fever. Whatever the detailed explanation, one important conclusion is clearly warranted. The next time you are suffering from a bout of flu and your fever is rising you may be unintentionally doing yourself a world of good because of the elevated temperature. Do not rush for the bottle of aspirin pills.

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