Chapter 017. Fever and Hyperthermia (Part 6)

Regimens for the Treatment of FeverThe objectives in treating fever are first to reduce the elevated hypothalamic set point and second to facilitate heat loss. Reducing fever with antipyretics also reduces systemic symptoms of headache, myalgias, and arthralgias.Oral aspirin and NSAIDs effectively reduce fever but can adversely affect platelets and the gastrointestinal tract. Therefore, acetaminophen is preferred to all of these agents as an antipyretic. In children, acetaminophen must be used because aspirin increases the risk of Reyes syndrome. If the patient cannot take oral antipyretics, parenteral preparations of NSAIDs and rectal suppository preparations of various antipyretics can be...
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Chapter 017. Fever and Hyperthermia (Part 6) Chapter 017. Fever and Hyperthermia (Part 6) Regimens for the Treatment of Fever The objectives in treating fever are first to reduce the elevatedhypothalamic set point and second to facilitate heat loss. Reducing fever withantipyretics also reduces systemic symptoms of headache, myalgias, andarthralgias. Oral aspirin and NSAIDs effectively reduce fever but can adversely affectplatelets and the gastrointestinal tract. Therefore, acetaminophen is preferred to allof these agents as an antipyretic. In children, acetaminophen must be used becauseaspirin increases the risk of Reyes syndrome. If the patient cannot take oralantipyretics, parenteral preparations of NSAIDs and rectal suppositorypreparations of various antipyretics can be used.Treatment of fever in somepatients is highly recommended. Fever increases the demand for oxygen (i.e., forevery increase of 1°C over 37°C, there is a 13% increase in oxygen consumption)and can aggravate preexisting cardiac, cerebrovascular, or pulmonaryinsufficiency. Elevated temperature can induce mental changes in patients withorganic brain disease. Children with a history of febrile or nonfebrile seizureshould be aggressively treated to reduce fever, although it is unclear what triggersthe febrile seizure and there is no correlation between absolute temperatureelevation and onset of a febrile seizure in susceptible children.In hyperpyrexia, theuse of cooling blankets facilitates the reduction of temperature; however, coolingblankets should not be used without oral antipyretics. In hyperpyretic patients withCNS disease or trauma, reducing core temperature mitigates the ill effects of hightemperature on the brain. Treating Hyperthermia A high core temperature in a patient with an appropriate history (e.g.,environmental heat exposure or treatment with anticholinergic or neurolepticdrugs, tricyclic antidepressants, succinylcholine, or halothane) along withappropriate clinical findings (dry skin, hallucinations, delirium, pupil dilation,muscle rigidity, and/or elevated levels of creatine phosphokinase) suggestshyperthermia. Attempts to lower the already normal hypothalamic set point are oflittle use. Physical cooling with sponging, fans, cooling blankets, and even icebaths should be initiated immediately in conjunction with the administration of IVfluids and appropriate pharmacologic agents (see below). If insufficient cooling isachieved by external means, internal cooling can be achieved by gastric orperitoneal lavage with iced saline. In extreme circumstances, hemodialysis or evencardiopulmonary bypass with cooling of blood may be performed.Malignanthyperthermia should be treated immediately with cessation of anesthesia and IVadministration of dantrolene sodium. The recommended dose of dantrolene is 1–2.5 mg/kg given intravenously every 6 h for at least 24–48 h—until oraldantrolene can be administered, if needed. Procainamide should also beadministered to patients with malignant hyperthermia because of the likelihood ofventricular fibrillation in this syndrome. Dantrolene at similar doses is indicated inthe neuroleptic malignant syndrome and in drug-induced hyperthermia and mayeven be useful in the hyperthermia of the serotonin syndrome and thyrotoxicosis.The neuroleptic malignant syndrome may also be treated with bromocriptine,levodopa, amantadine, or nifedipine or by induction of muscle paralysis withcurare and pancuronium. Tricyclic antidepressant overdose may be treated withphysostigmine. Acknowledgment The substantial contributions of Jeffrey A. Gelfand to this chapter inprevious editions are gratefully acknowledged. FURTHER READINGS De Koning HD et al: Beneficial response to anakinra and thalidomide inSchnitzlers syndrome. Ann Rheum Dis 65:542, 2006 Dinarello CA: Infection, fever, and exogenous and endogenous pyrogens:Some concepts have changed. J Endotoxin Res 10:202, 2004 Hawkins PN et al: Spectrum of clinical features in Muckle-Wells syndromeand response to anakinra. Arthritis Rheum 50:607, 2004 [PMID: 14872505] Hoffman HM et al: Prevention of cold-associated acute inflammation infamilial cold autoinflammatory syndrome by interleukin-1 receptor antagonist.Lancet 364:1779, 2004 [PMID: 15541451] Keane J et al: Tuberculosis associated with infliximab, a tumor necrosisfactor-α-neutralizing agent. N Engl J Med 345:1098, 2001 [PMID: 11596589] Pascual V et al: Role of interleukin-1 (IL-1) in the pathogenesis of systemiconset juvenile idiopathic arthritis and clinical response to IL-1 blockade. J ExpMed 201:1479, 2005 [PMID: 15851489] Simon A, van der Meer JW: Pathogenesis of familial periodi ...