Procalcitonin Levels, Severity of Illness, and Mortality in Cancer Patients Admitted to the ICU With Severe Sepsis

Abstract

PURPOSE: To determine the relationship of serum procalcitonin (PCT) levels with severity of illness and mortality in cancer patients admitted to the ICU with severe sepsis. METHODS: Serum PCT levels were measured (VIDAS Brahms PCT, Biomerieux) in patients with cancer who were admitted to an oncologic ICU with severe sepsis over a 6-month period. PCT levels were obtained within 24h and 48-72h of ICU admission, unless the patient expired. Data collected included demographics, admitting service, type of malignancy, Mortality Probability Model II score (MPM-II0) and blood lactate level on ICU admission, source of infection, use of mechanical ventilation (MV) and vasopressors (VP), and hospital mortality. Data are presented as mean (+SD), absolute numbers or percentages. Statistical analyses used were Student's t-test, chi-square and Spearman's nonparametric correlation tests. RESULTS: 63 PCT levels from 33 patients were analyzed. Mean age was 61 years, 70% were male, and mean MPM II0 was 41%. 18 (55%) were medical patients and 15 (45%) surgical. 10 (30%) had hematologic malignancy and 23 (70%) had solid tumors. Sources of infection were lung (17=52%), abdomen (11=33%), catheter-related (2=6%), urine (1=3%), skin/soft tissue (1=3%) and undetermined (1=3%). 17 (52%) received MV and 20 (61%) required VP. Hospital mortality was 39%. Nonsurvivors (NS) compared to survivors (S) had higher MPM II0 (60% vs. 29%) and PCT levels at 24 and 48-72h of ICU admission (38 (+61) and 44 (+ 71) ng/ml vs. 12 [+23] and 8 [+15] ng/ml, respectively). Lactate levels were similar for both groups (2.2 for NS vs. 2.0 mmol/L for S). PCT levels at 24h and 48-72h of ICU admission did not correlate with MPM II0 (p=0.183) and mortality (p=0.55 and p=0.40, respectively). CONCLUSIONS: Severity of illness and PCT levels at 24 and 48-72h of ICU admission were higher in cancer patients with severe sepsis who died compared to those who survived. However, PCT levels at 24 and 48-72h were not statistically significant in predicting mortality.