Severe community-acquired pneumonia. Assessment of severity criteria.
The purpose of the study was to validate the criteria used in the guidelines of the American Thoracic Society (ATS) for severe community-acquired pneumonia (CAP). Severe pneumonia was defined as admission to the intensive care unit (ICU). Overall 331 nonsevere (84%) and 64 severe cases (16%) of CAP were prospectively studied. Mortality was 19 of 395 (5%) and 19 of 64 (30%), respectively. Single severity criteria as well as the ATS definition of severe pneumonia were assessed calculating the operative indices. A modified prediction rule including minor (baseline) and major (baseline or evolutionary) criteria was derived. Single minor criteria at admission had a low sensitivity and positive predictive value. Defining severe pneumonia according to the ATS guidelines had a high sensitivity (98%). However, specificity and positive predictive value were low (32% and 24%, respectively). A modified prediction rule (presence of two or three minor criteria [systolic blood pressure < 90 mm Hg, multilobar involvement, PaO2/FIO2 < 250] or one of two major criteria [requirement of mechanical ventilation, presence of septic shock]) had a sensitivity of 78%, a specificity of 94%, a positive predictive value of 75%, and a negative predictive value of 95%. The ATS definition of severe pneumonia was highly sensitive but insufficiently specific and had a low positive predictive value. Our suggested modified rule had a more balanced performance and, if validated in an independent population, may represent a more accurate definition of severe CAP.
Ewig
S
S
Servei de Pneumologia i Al.lèrgia Respiratoria, Servei de Malalties Infeccioces, Servei de Microbiologia, Hospital Clinic, Universitat de Barcelona, Spain.
Ruiz
M
M
Mensa
J
J
Marcos
M A
MA
Martinez
J A
JA
Arancibia
F
F
Niederman
M S
MS
Torres
A
A
D018806:APACHE; D000368:Aged; D001794:Blood Pressure / Q000502:physiology; D017714:Community-Acquired Infections / Q000145:classification* / Q000401:mortality / Q000601:surgery; D003422:Critical Care; D018450:Disease Progression; D005260:Female; D005544:Forecasting; D006801:Humans; D008168:Lung / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010343:Patient Admission; D011014:Pneumonia / Q000145:classification* / Q000401:mortality / Q000601:surgery; D017410:Practice Guidelines as Topic; D011237:Predictive Value of Tests; D011446:Prospective Studies; D051437:Renal Insufficiency / Q000150:complications; D015203:Reproducibility of Results; D012121:Respiration, Artificial; D012131:Respiratory Insufficiency / Q000150:complications; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D012772:Shock, Septic / Q000150:complications; D013030:Spain / Q000453:epidemiology; D015996:Survival Rate