ARCHIVES
OF
PRACTICAL PEDIATRICS
A News Letter Devoted To Practical Pediatric Practice
Volume 4 Issue 7 Date JULY 2022
Editor in Chief :
BD Gupta
Ass Editor :
RK Maheshwari
Mohan Makwana
Anil Arora
Regional Editors
Pankaj Agrawal
Avinash Bansal
Anil Jain
PC Khatri
Priyanshu Mathur
Jai Singh Meena
Adarsh Purohit
Editorial advisory Board
Neeraj Gupta
Manoj Jangid
Rakesh Jora
Amarjeet Mehta
Lakhan Poswal
GS Sengar
Pramod Sharma
Anurag Singh
Kuldeep Singh
S Sitaraman
Management Of Fever In Pediatric Practice
Dr Rakesh Dudi
Dr Adarsh Purohit.
Introduction
Fever is the most common symptom with which a patient is brought in pediatric outdoor for consultation. As a clinician we have to take a thorough history and examination to diagnose the cause of fever upon which rests its management, but before that we have to confirm the presence of fever. Once we have confirmed the presence then we proceed to further management. In this article, we will be discussing various methods to record fever to confirm its presence and various anti-pyretic drugs which are used commonly, with their mechanism of action and side-effects. Tympanic Membrane Temperature Measurement is one of the most reliable among the various sites used for body temperature measurement. Paracetamol is the anti-pyretic of choice and other NSAIDs should be avoided as far as possible.
Introduction
Fever is the most common symptom with which a patient is brought in pediatric outdoor for consultation. As a clinician we have to take a thorough history and examination to diagnose the cause of fever upon which rests its management, but before that we have to confirm the presence of fever. Once we have confirmed the presence then we proceed to further management. In this article, we will be discussing various methods to record fever to confirm its presence and various anti-pyretic drugs which are used commonly, with their mechanism of action and side-effects. Tympanic Membrane Temperature Measurement is one of the most reliable among the various sites used for body temperature measurement. Paracetamol is the anti-pyretic of choice and other NSAIDs should be avoided as far as possible.
Measurement of Body Temperature
Body temperature measurement is most commonly performed to confirm the presence or absence of fever. Many decisions concerning the investigation and treatment of children are based on the results of temperature measurement alone. An incorrect temperature measurement could result in delayed detection of a serious illness, or alternatively an unnecessary septic workout. Despite the plethora of instruments available, there remains considerable controversy as to the most appropriate thermometer and the best anatomical site to measure body temperature.
Core Temperature
There is no uniform core temperature throughout the body. The hypothalamus is the site where body temperature is set and where the highest body temperature is recorded. Since the hypothalamus is inaccessible, core temperature is generally defined as the temperature measured within the pulmonary artery. Other standard core temperature monitoring sites are distal esophagus, urinary bladder and nasopharynx. Since these deep-tissue measurement sites are clinically inaccessible, physicians have been using rectum as a practical site to monitor body temperature with the belief that this site most accurately reflects core temperature.
Temperature Measurement: Accurate or Screening
Pediatricians are usually only interested in the presence or absence of fever and its approximate degrees. For pediatricians, small variations in body temperature is lesser important a parameter as compared to the clinical condition of the child i.e. how well or ill the child looks. The presence of fever and its severity can be vital indicators of conditions that need careful investigations and prompt treatment of the underlying disease. The accuracy of body temperature measurement is particularly important in the following situations:
- Fever in a neutropenic child with cancer
- Children with sickle-cell anaemia
- Infants younger than 3 months
- To differentiate between Epilepsy (recurrent non febrile seizure) and Febrile seizure
- Critically ill children in intensive care unit
- During anaesthesia continuous body temperature monitoring is essential
- Hypothermic neonates on admission to NICU
- Drowning and Near-drowning cases
Tactile Assessment
Simple palpation has been used for thousands of years to assess body temperature and it is still the most widely used method of evaluating body temperature in busy outdoor patient department. The drawback with this method is that it is less accurate and sensitive, and depends upon observer or examiner’s hand temperature. This method is also far from accuracy mainly because of lowering of skin temperature during the early phase of fever due to vasoconstriction. However, it has been observed that detection of fever by touching the child by a mother is more sensitive than that by a medical personnel.
Instrumentation
An ideal thermometer must
- Accurately reflect core body temperature in all age groups.
- Be convenient, easy and comfortable to use by parents and practitioner, without causing embarrassment.
- Give rapid results.
- Not result in cross infection.
- Not be influenced by ambient temperature.
- Be safe.
- Be cost-effective.
- Possess high reproducibility
Types of Thermometer
- Mercury thermometer has been used for long in office practice as well as in admitted patients, but it is being phased out now-a-days because of environmental concern.
- Chemical Dots thermometer (Tempa Dot): these are re-usable or single-use disposable plastic-encased thermophototropic liquid crystals for forehead application. The substance changes color as the temperature rises. They are most suitable for home use. Its advantage is that it is convenient to use, is safe, comfortable and provide rapid results. The drawback of this device is that temperature measurement by this device is inaccurate and it frequently records a normal temperature despite presence of fever.
- Infrared Thermometer (Temporal artery thermometer (TAT), Tympanic membrane Thermometer): These types of thermometers measure the temperature by detecting the thermal infrared energy. They are easy to use, but their accuracy remains a problem, with only 66% sensitivity to accurately detect fever.
- Electronic or Digital Thermometer: It measures temperature by monitoring changes in electrical properties i.e. voltage and resistance of metals inside the device. It can be used to measure rectal, axillary and oral temperatures. It is not influenced by environmental temperature (when used orally or rectally) and gives quick result in 30 seconds.
National Institute of Health and Care Excellence (NICE) Guidelines for Body Temperature measurement
- In infants under the age of 4 weeks, body temperature should be measured with an electronic thermometer placed in axilla.
- In children aged 4 weeks to 5 years, healthcare professionals should measure body temperature by one of the following methods:
1. Electronic thermometer in the axilla
2. Chemical dot thermometer in the axilla
3. Infrared tympanic thermometer in the ear
- Forehead chemical thermometers are unreliable.
Sites of Temperature Measurement
Axillary Temperature (AT)
| Advantages | Disadvantages |
| Ø Safe
Ø Easily accessible and comfortable. Ø In neonatal units, AT measurements are as accurate as rectal measurements
|
Ø Requires supervision, otherwise displacement may occur.
Ø Measurement takes longer than on other sites, e.g. 30–40s by electronic thermometer which is not cost-effective with regard to nursing time. Ø Measurement may be inaccurate as the effects of sweating and evaporation can cause inaccuracy |
Skin Temperature (ST)
An infrared thermometer or temporal artery thermometer that scans the surface from the forehead to behind the ear can be used for this purpose, with the highest temperature being recorded over the temporal artery. Although this device has been found to be easy to use (a gentle stroke across the forehead and then placement behind the earlobe), its accuracy remains a problem, with only 66% sensitivity to detect fever. Comparison of temporal artery temperature with pulmonary artery temperature measurements have shown only modest agreement between the two sites.
| Advantages | Disadvantages |
| Ø Convenient
Ø Easy to use with safety Ø Comfortable Ø Rapid results |
Ø Measurement is inaccurate, frequently records falsely normal temperature despite elevated core body temperature |
Oral Cavity Temperature
| Advantages | Disadvantages |
| Ø Not affected by ambient temperature.
Ø Easily accessible and accurate. Ø Accurate with excellent correlation with pulmonary arterial temperature |
Ø Requires co-operation, therefore not suitable in children <5 years of age, in children with developmental delay, or in comatose or intubated patients.
Ø Hot baths, exercise, hot and cold drinks and mouth breathing influence the results. Ø Accuracy relies on sealed mouth. Ø The site should not be used in case of tachypnoea which causes cooling of the mouth. Ø There is variation in temperature recorded depending on where the bulb is placed. |
Rectal Temperature (RT)
| Advantages | Disadvantages |
| Ø Widely viewed as the gold standard concerning accuracy
Ø The site is not influenced by ambient temperature and its use is not limited by age |
Ø It is frightening for small children and may be psychologically harmful for older children.
Ø Can cause discomfort and is painful for patients with perirectal infection or irritation. Ø Site is not hygienic and presents an infectious hazard. Ø The transmission of HIV through this route is a concern. Ø RT should not be used in patients with neutropenia. Oncology centers routinely avoid this site. Ø Measurement is time-consuming, requires privacy and has been reported to cause rectal perforation. Ø RT varies depending on how deeply the thermometer is inserted into the rectum, local blood flow, and the presence of stool and diarrhea. Ø It lags significantly behind a rapidly rising or falling core temperature, therefore RT should not be used for patient’s temperature monitoring during anaesthesia |
Tympanic Membrane Temperature (TT)
A tympanic infrared thermometer is used with a disposable probe. The pinna is first gently retracted, and the thermometer is inserted a few millimeters inside the left external ear canal until a beep indicates completion of the measurement. The measurement is repeated twice and the highest reading is recorded. As the tympanic membrane receives its blood supply from the carotid artery, its temperature may reflect that of blood flowing into the hypothalamus, thereby correlating closely with core body temperature.
| Advantages | Disadvantages |
| Ø Fast and easy to use
Ø Without risk of cross infection Ø Uninfluenced by environmental temperature Ø Saves nursing time, so cost-effective |
Ø Crying, OM and ear wax may interfere in measurement
Ø The main reason why the TT has yet to be regarded as the gold standard for body temperature measurement is that some studies have reported inaccuracies, mainly in children younger than 2–3 years of age |
Final words
- Axillary temperature measurement is not accurate
- Rectal temperature measurement is not favored by parents and nurses
- The oral temperature measurement is not used in children less than 5 years of age
- Tympanic site infrared thermometer is the most suitable for use in hospitals and home
Management of Fever (Use of Antipyretics)
- The principal indication for the use of antipyretics is not to reduce body temperature but to make the child comfortable. It has been well documented that antipyretics are ineffective in preventing febrile seizures. Currently, Paracetamol is the first-line choice for fever management. It has also been observed that combining two antipyretics has no scientific basis and does not achieve a greater antipyretic/analgesic effect than either agent alone. In therapeutic dose, antipyretics rarely cause adverse events.
- The use of tepid sponging for febrile children is rarely needed because of the availability of antipyretic drugs, which are simpler to use, more effective in reducing body temperature and produce less discomfort to children.
- One of the most important duties of pediatricians is to differentiate between an ill child (who may need prompt attention, including hospitalization) and a well child who can be sent home. This comes with experience.
- Fever phobia is common among parents and doctors. This excessive fear of fever is unfounded. It is not the fever which is harmful but the underlying disease.
Mechanisms of Action of Antipyretics
- Antipyretics act centrally by lowering the thermoregulatory set-point of the hypothalamic center. This is achieved through inhibition of cyclooxygenase (COX) enzyme and production of prostaglandins (PG) and leukotrienes. Most antipyretics inhibit PG effects and reduce the classical signs of inflammation.
- Antipyretics do not reduce fever to a normal level, neither do they reduce the duration of febrile episodes or interfere with the normal body temperature. They also do not directly interfere with pyrogen formation or with mechanisms of heat loss, such as sweating. Their effectiveness in reducing fever depends on the level of fever (the higher the fever, the more the reduction), the absorption rate and the dose of the antipyretic.
Indications for Antipyretics
Antipyretics are mainly used to lower fever and abolish pain. The primary goal of treating febrile children should be to improve the overall comfort rather than focusing on lowering body temperature and thereby reducing the parents’ anxiety. Therefore, improving the comfort and evaluating for serious illness should be the therapeutical end points of fever management. There is no evidence that fever causes brain damage or that antipyretics prevent febrile seizures. There is also no evidence to suggest that reduction of body temperature reduces morbidity or mortality from a febrile illness. If there is morbidity or mortality, it comes from the underlying illness rather than from the fever.
Current pediatric practice for a febrile child includes the use of antipyretics when the temperature is greater than 38.5°C. With the reduction of fever, the activity and alertness of children may improve, while the improvement in mood or appetite is less pronounced. Improved activity should encourage children to take fluid, which is essential in the treatment of febrile children. Paracetamol and ibuprofen are frequently used as antipyretic-analgesic to reduce fever and associated body pain. A common practice is to recommend the routine use of paracetamol or ibuprofen before receiving immunization (aimed at reducing discomfort associated with the injection), but this practice may decrease immune response to vaccination leading to sub-optimal antibody level.
A practice frequently used to control fever is the alternating or combined use of paracetamol and ibuprofen. This practice has the potential of inaccurate dosing and overdosing and does not cause improved comfort. External cooling measures such as tepid sponging can reduce fever, but they do not improve comfort which is the goal of antipyretic use.
Choosing an Antipyretic
Various NSAIDs have been used over the years to control fever. Aspirin is one of the oldest medicines used for this purpose, but in 1988, aspirin was removed from the World Health Organization’s list of essential drugs following reports linking aspirin and Reye’s syndrome (encephalopathy associated with liver necrosis). Presently, Paracetamol is the most commonly used as well as the safest antipyretic. Ibuprofen and Mefenamic Acid also have a good anti-pyretic effect, but they may lead to severe adverse effects, so they should not be used routinely either alone or in combination form.
Paracetamol (Acetaminophen)
Paracetamol is the most commonly used antipyretic and analgesic drug in pediatric practice. It is the only available drug for fever and pain in children from birth and younger than 3 months of age. Ibuprofen should not be used at this age for its potential to cause serious side-effects. Its clearance is reduced in neonates, so a dosing at 8–12 hours interval is recommended in neonates. It is the first choice for antipyresis and analgesia, but has no anti-inflammatory property. Unlike ibuprofen, paracetamol can be safely used in children with dehydration and with chickenpox. Following administration of a therapeutic dose, fever begins to fall in about 30 min, a nadir is reached in about 2 h and recurrence of fever is observed after 3–4 h. A peak plasma level is reached in about 30 min. It can be administered by Oral, IM, or IV route with safety. The dose of paracetamol for oral use is 10-15 mg/kg per dose, may be repeated 4-6 hourly. When used by rectal route in form of suppository the dose is 15-30 mg/kg as the absorption may be erratic in some cases.
Use of IV Paracetamol
- Advantage: Penetrates readily in CSF, provides rapid central analgesia bypassing the delayed absorption of enteral route
- Disadvantage: May cause transient hypotension. Few indications where it can be used by intravenous route is for intra-operative or postoperative analgesia, but not as an antipyretic.
Paracetamol Toxicity/Poisoning
Paracetamol is the most common drug used for self-poisoning in the UK, although toxic dose of paracetamol is high i.e. >150 mg/kg in a child.
Management of PCM toxicity
- Plasma paracetamol measurement should be performed 4 h after ingestion
- Activated charcoal is administered to minimize the drug absorption.
- Specific antidote is N-acetylcysteine. It is to be given in standard dose of 300 mg/kg administered intravenously over a 20 h period.
Fever is a very common complaint in children and how sick the child looks is more important than the level of fever. Most children aged 0–36 months who have fever have a focus of infection, which can be identified by careful history and examination. A viral upper respiratory tract infection is the most common focus. Most children aged 0–36 months without an obvious focus of infection have viral infections, but they may harbor two important serious bacterial infections (SBI): urinary tract infection and bacteremia. Febrile neonates and ill-looking children, regardless of age, are at high risk for SBI and need antibiotic coverage, hospital admission and comprehensive septic work-up. This include blood and urine cultures, CBC, CRP, and, when indicated, chest X-ray and Lumbar Puncture. Children aged 1–36 months without a focus may be treated more selectively: if the i) temperature is >39 °C, ii) WBC count is >15,000/mm3, and iii) CRP >40 mg/L, urine and blood cultures should be ordered and a third-generation cephalosporin (ceftriaxone or cefotaxime) may be considered. So, prompt identification of fever, diagnosing the cause and treating the cause of fever is the key in a febrile child.
References
1.Kluger MJ, Ringler DH, Anver MR. Fever and survival. Science. 1975;188:166–8.
2.Bernheim HA, Kluger MJ. Fever: of drug-induced antipyresis on survival. Science. 1976;193:237–9.
3.Graham NH, Burrell CJ, Douglas RM, et al. Adverse effects of aspirin, acetaminophen, and ibuprofen on immune function, viral shedding and clinical status in rhinovirus-infected volunteers. Infect Dis. 1990;162:1277–82.
4.Doran TF, Angelis CD, Baumgarder RA, et al. Acetaminophen: more harm than good in chickenpox? J Pediatr. 1989;114:1045–8.
