Fever.pdf

3/27/24, 5:59 AM Fever Fever Yvonne M. Shevchuk, BSP, PharmD, FCSHP Date of Revision: April 20, 2021 Peer Review Date: May 1, 2018 CPhA acknowledges Dr. Joanne M. Langley for her contributions to this chapter. Introduction Fever is a regulated physiologic response in which a new thermal set-point fo...

3/27/24, 5:59 AM Fever Fever Yvonne M. Shevchuk, BSP, PharmD, FCSHP Date of Revision: April 20, 2021 Peer Review Date: May 1, 2018 CPhA acknowledges Dr. Joanne M. Langley for her contributions to this chapter. Introduction Fever is a regulated physiologic response in which a new thermal set-point for body temperature is established by the hypothalamus. In response, the body establishes a new equilibrium of heat loss and production to maintain homeostasis at the higher temperature.​ Fever is distinguished from disorders of temperature regulation, such as hyperthermia (see Heat-Related Disorders), where heat production exceeds heat loss without an increase in the thermoregulatory set-point. Children 6 months of age, recurrent fever or high fever (>40.5°C) should be evaluated by an appropriate health-care practitioner (see Figure 1 for red flags). Although uncommon, fever may be drug-induced; Table 1 lists medications that may be associated with drug-induced fever. Table 1: Selected Drugs Associated with Fever​ Allopurinol Diltiazem Methyldopa Amphotericin B Doxepin Metoclopramide Antacid Epinephrine Mycophenolate Antibacterials/antibiotics, e.g., cephalosporins, penicillins, SMX/TMP Folic acid Nifedipine Furosemide Anticholinergics Griseofulvin NSAIDs, e.g., ibuprofen, naproxen Antihistamines Heparin Oral contraceptives Antineoplastics, e.g., cisplatin, hydroxyurea Hydralazine Phenytoin Hydrochlorothiazide Procainamide H2-receptor antagonists (e.g., cimetidine) Propylthiouracil Insulin Quinine Interferon Rifampin Iodides Salicylates Iron dextran Sulfasalazine Isoniazid Tacrolimus MAOIs Triamterene Antipsychotics Atropine Azathioprine Barbiturates Carbamazepine Clofibrate Corticosteroids Cyclosporine Digoxin Quinidine Vitamins Abbreviations: MAOIs = monoamine oxidase inhibitors; NSAIDs = nonsteroidal anti-inflammatory drugs; SMX/TMP = sulfamethoxazole/trimethoprim Measurement of Body Temperature Measurement of “core” body temperature (e.g., viscera, major arteries) is invasive and impractical except in ICU settings; therefore the oral, rectal, axillary, temporal artery, tympanic membrane and transcutaneous routes are used to approximate core temperature. Different anatomic sites have different temperatures, so all are approximations of https://cps-pharmacists-ca.login.ezproxy.library.ualberta.ca/print/new/documents/MA_CHAPTER/en/fever_selfcare 2/14 3/27/24, 5:59 AM Fever “body” temperature.​ Although measurement error can occur with any method, in children ≤5 years of age, rectal thermometry is the gold standard in Canada for definitive measurement of temperature.​ Other temperature measurement methods can be used as a screening tool for low-risk children; these include tympanic temperature measurement in children ≥2 years of age and axillary temperature measurement in children of all ages.​ In children >5 years of age and adults, oral thermometry is recommended for confirmation of fever.​ Invasive measurement of temperature in critically ill adults and children, and temperature control in this population, is beyond the scope of this chapter. The non-invasive methods of measuring temperature in the ambulatory setting (rectal, oral, axillary, ear/tympanic membrane, transcutaneous and temporal artery) are listed in Table 2.​ Oral, rectal and axillary temperatures may be taken with an electronic thermometer with a digital display (digital probe). Normal, route-specific temperature ranges and preferred routes based on age are listed in Table 3. Table 2: Methods of Measuring Body Temperature Method Description Rectal​ Recommended for definitive temperature measurement in children