Body temperature alterations in the critically ill

To determine the incidence of body temperature (BT) alterations in critically ill patients, and their relationship with infection and outcome.

Prospective, observational study.

Thirty-one bed, medico-surgical department of intensive care.

Adult patients admitted consecutively to the ICU for at least 24 h, during 6 summer months.

None.

Fever (BT≥38.3°C) occurred in 139 (28.2%) patients and hypothermia (BT≤36°C) in 45 (9.1%) patients, at some time during the ICU stay. Fever was present in 52 of 100 (52.0%) infected patients without septic shock, and in 24 of 38 (63.2%) patients with septic shock. Hypothermia occurred in 5 of 100 (5.0%) infected patients without septic shock and in 5 of 38 (13.1%) patients with septic shock. Patients with hypothermia and fever had higher Sequential Organ Failure Assessment (SOFA) scores on admission (6.3±3.7 and 6.4±3.3 vs 4.6±3.2; p<0.01), maximum SOFA scores during ICU stay (7.6±5.2 and 8.2±4.7 vs 5.4±3.8; p<0.01) and mortality rates (33.3 and 35.3% vs 10.3%; p<0.01). The length of stay (LOS) was longer in febrile patients than in hypothermic and normothermic (36°C<BT<38.3°C) patients [median 6 (1–57) vs 5 (2–28) and 3 (1–33) days, p=0.02 and p=0.01, respectively). Among the septic patients hypothermic patients were older than febrile patients (69±9 vs 54±7 years, p=0.01). Patients with septic shock had a higher mortality if they were hypothermic than if they were febrile (80 vs 50%, p<0.01).

Both hypothermia and fever are associated with increased morbidity and mortality rates. Patients with hypothermia have a worse prognosis than those with fever.