Pyrexia - PACT - ESICM

Task 4. Understanding and treating fever
loss, when the thermostat is set again to the normal level. Shivering occurs in
the first period (heat gain) and sweating in the second one (heat loss).
For every degree centigrade increase in temperature, oxygen demand
and energy expenditure are said to increase by about 6–10%. Sedation,
anaesthesia and cooling may decrease oxygen demand while shivering has the
opposite effect. When cooling results in shivering, oxygen demand may also
increase.
Treating fever
There is ongoing debate as to the benefit of physical or pharmacologic lowering
of core temperature exceeding 40 °C with the attendant risk of cerebral damage.
Indeed, we previously noted that brain damage may be anticipated when the
duration of fever of >42 ° C exceeds one hour; higher temperatures may be
tolerated for much shorter periods. In patients with sepsis, NSAIDs may
attenuate the febrile response. In patients with severe sepsis, ibuprofen has
been shown to lower body temperature, tachycardia and lactic acidosis but no
other haemodynamic, respiratory, or survival benefit was demonstrated.
Although this type of drug may be associated with renal dysfunction,
particularly in hypovolaemic subjects, the administration appeared safe.
Antipyretics may also include paracetamol (acetaminophen) (orally or rectally)
or diclofenac (0.04 mg/kg/h continuous i.v. infusion) if available. Overzealous
treatment with NSAIDs may augment inflammatory responses.
Mackowiak PA. Physiological rationale for suppression of fever. Clin Infect Dis
2000; 31 Suppl 5: S185–189. PMID 11113022
Manthous CA. Toward a more thoughtful approach to fever in critically ill
patients. Chest 2000; 117(3): 627–628. PMID 10712983
[42]