Objectives:
Community-acquired pneumonia (CAP) is associated with a high risk of respiratory failure
or septic organ dysfunction. Lactate is an established early marker of prognosis and
sepsis severity, but few data exist in patients with CAP.
Methods:
We performed a retrospective cohort study of consecutive adult CAP patients without
treatment restrictions or direct ICU admission. Lactate was measured as point of care
test within the capillary admission blood gas analysis and its prognostic value was
compared to the CRB/CURB-65 criteria by multivariate and ROC curve analysis. The primary
endpoint was the combination of need for mechanical ventilation, vasopressors, ICU
admission or hospital mortality.
Results:
Of 303 included patients, 75 (25%) met the primary endpoint. After ROC analysis, lactate
predicted the primary endpoint (AUC 0.67) with an optimal cut-off of > 1.8 mmol/l.
Of the 76 patients presenting with lactate above this threshold, 35 (46%) met the
primary endpoint. After multivariate analysis, the predictive value of lactate was
independent of the CRB/CURB-65-scores. The addition of lactate > 1.8 mmol/l to the
CRB/CURB-65 scores resulted in significantly improved AUCs (0.69 to 0.74, p = 0.005
and 0.71 to 0.75, p = 0.008, respectively). Fourteen of 33 (42%) and 11 of 28 (39%)
patients meeting the endpoint despite presenting with 0 or 1 CRB-65/CURB-65 criteria
had lactate > 1.8 mmol/l.
Conclusions:
Admission lactate levels significantly improved the prognostic value of the CRB/CURB-65
scores in CAP patients. Lactate therefore should be considered as rapid, cheap and
broadly available additional criterion for the assessment of risk in patients with
CAP.
