Fever, which is simply an increase in body temperature, is a common pediatric condition and almost every child will experience the process of fever throughout their lifetime. Fever is a symptom, not a disease. The understanding of fever in humans is constantly evolving. Only by understanding the causes of fever can effective prevention and treatment be given.
Body temperature refers to the temperature in the human body, and humans can maintain a relatively constant body temperature, usually around 37°C. Compared to adults, the body temperature is slightly higher in newborns and slightly lower in older adults. Normal body temperature is an important physiological basis for various functional activities of the human body.
Body temperature arises from the oxidative metabolism of nutrients in the body. Therefore, changes in the metabolism of substances will affect the body temperature, such as people in motion or children crying, feeding or intake of high-protein, high-calorie food will accelerate metabolism, body temperature can be correspondingly higher; in a state of sleep or hunger, the body metabolic activity decreases, body temperature is also slightly lower. Conversely, too high or too low body temperature can also affect the body’s metabolism, and in serious cases, the body’s material metabolism failure.
The relative constancy of body temperature is governed by the thermoregulatory center of the brain and is achieved through the dynamic balance of the body’s chemical heat production and physical heat dissipation processes. In a cold environment, the body shivers and the skeletal muscles contract to produce heat; in a hot environment, the body’s sweat glands increase their ability to produce heat and dissipate heat. However, the body’s ability to regulate body temperature is limited, and when the body temperature exceeds normal body temperature, the ability to regulate decreases, and when the body temperature reaches 41℃ superheat, the ability to regulate is nearly lost. Therefore, for children with hyperthermia above 39℃, it is necessary to take medication to lower the temperature or effective physical cooling measures.
In addition, people can also make conscious behavioral adjustments based on the sensation of heat and cold, and increase or decrease clothing to adapt to the environment with climate change. It is worth noting that the central nervous system of infants and young children, especially newborns, is not yet well developed, and the thermoregulatory function is poor. Therefore, the body temperature fluctuates greatly. Parents should pay attention to the change in environmental temperature, increase or decrease the child’s clothing.
There is a more detailed medical classification of elevated body temperature, and what we usually call fever is actually one of the most common types of pathological body temperature increase. The causes of elevated body temperature are briefly represented in the following chart.
Clinically, we believe that the vast majority of pathologically elevated body temperatures are related to pathogenic infections, which are familiar with having inflammation that stimulates the body to become febrile. Therefore, when a family member brings a child with acute fever to the doctor, the doctor often prescribes routine blood and CRP tests to clarify the type and degree of infection. Based on the test report and physical examination, the doctor determines the nature (viral or bacterial infection) and location (tonsils, bronchi, lungs, urinary tract, etc.) of the infection and treats it accordingly.
Since the child has a fever, the doctor will give antipyretic treatment. What kind of antipyretic treatment is appropriate? What does the family need to do?
1. Acute fever should be treated promptly by cooling, especially high fever. Because there is research to prove that, as far as the temperature itself, a body temperature of about 38 ℃ is beneficial for the body to clear pathogenic microorganisms, but ultra-high fever of more than 41 ℃ is harmful to the body. Therefore, for axillary temperature above 38.5℃, we recommend giving antipyretic drugs (antipyretic and analgesic drugs: such as ibuprofen, acetaminophen, etc.) to reduce the temperature, and physical methods (such as warm water bath) can be given to assist in reducing the fever.
2. For the treatment of low-moderate fever, I suggest more observation and try not to use antipyretic drugs. Because the temperature below 39℃ can be tolerated by children in general. It is more beneficial to drink more water, reduce clothing and wipe the body with warm water, and observe the trend of temperature changes in the child.
Due to the imperfect development of the nervous system in children under 3 years old, about 10% of children may have convulsions (febrile convulsions) in the early stages of fever. If the convulsions are due to simple fever, there are generally no adverse consequences as long as they do not last long (<15min) and there is no vomiting and asphyxia. However, recurrent convulsions, altered consciousness, and even feverless convulsions should be taken seriously by the family and may have central nervous system disorders and should be seen in a child neurologist.
4.Does fever need to be treated with antibiotics? This is a big problem that I found in the course of my medical practice, and it is also a rather complicated issue.
(1) Whether antibiotics are needed is determined by the patient’s disease itself. Antibiotics should usually be used in the following cases.
(1) Confirmed bacterial infection.
2) Severe malnutrition combined with infection.
3) immunocompromised co-infection.
4) preoperative prophylactic antibiotics in some patients.
(5) Some perioperative patients need antibiotics.
(2) Antibiotics have no direct antipyretic effect. Fever is only a concomitant symptom of a disease, and it is the antipyretic and analgesic drugs that have a direct antipyretic effect. More than 90% of respiratory infections in outpatient clinics are viral infections, and fever due to viral infections is self-limiting and usually stops on its own in about 3 days. So many families ask me why I do not prescribe antibiotics to reduce inflammation for viral colds, now you can understand, right?
(3) The direct use of antipyretic drugs to reduce fever is to treat the symptoms but not the root cause, so treating the cause of the fever is the fundamental treatment. If the treatment of the primary disease requires the use of antibiotics, then use a full course of treatment, if not, then decisively do not use.
(4) The choice of antibiotics is something that tests the doctor’s level and professional ethics. I found in my clinical work, many doctors use antibiotics are very blind, and even some doctors use antibiotics as the basis for the treatment of disease, which is completely wrong. The sad thing is that many families still superstitiously believe that antibiotics are a panacea, and even rush with you without giving him antibiotics (I really feel sad). So antibiotics are not a cure-all!!!
5.Does fever need fluids? My answer is: most fevers do not require fluids. Most acute fevers are the result of the activation of the body’s immunity after infection, which is a normal physiological process. Observation of the fever pattern and fever duration has a positive effect on the judgment of the disease and the development of a treatment plan. The common modes of administration are oral, intramuscular, and intravenous infusion. Most diseases have multiple modes of drug administration. In principle, if a drug can be given orally, it is not given intramuscularly, and if it can be given intramuscularly, it is not given by infusion.
What are the conditions that require infusion therapy? The following conditions require intravenous infusion therapy.
1) Patients who cannot take in orally or whose oral intake is insufficient to maintain their physiological needs, such as patients who are comatose and dehydrated.
2) Patients who need rapid replenishment of effective blood volume, such as those in shock.
3) resuscitation of critically ill patients.
4) Patients requiring infusion to maintain urine output and prevent renal failure.
5) promotion of toxic excretion.
6) supplementation of nutrition and calories.
7) Patients who need to maintain a more stable blood concentration to achieve the best therapeutic effect, such as patients with sepsis and septic meningitis. It is easy to see that in fact, the vast majority of children who visit the clinic do not meet the criteria for infusion, but in practice there are still many patients who are treated with infusion. There are many reasons for this, including the national health care system, doctors’ reasons, and patients’ reasons, so I won’t go into further details.