title: Early Diagnosis of Pneumonia in Severe Stroke: Clinical Features and the Diagnostic Role of C-Reactive Protein.
abstract: BACKGROUND
  Accurate diagnosis of pneumonia complicating severe stroke is challenging due to difficulties in physical examination, altered immune responses and delayed manifestations of radiological changes. The aims of this study were to describe early clinical features and to examine C-reactive protein (CRP) as a diagnostic marker of post-stroke pneumonia.
  
  
  METHODS
  Patients who required nasogastric feeding and had no evidence of pneumonia within 7 days of stroke onset were included in the study and followed-up for 21 days with a daily clinical examination. Pneumonia was diagnosed using modified British Thoracic Society criteria.
  
  
  RESULTS
  60 patients were recruited (mean age 77 years, mean National Institutes of Health Stroke Scale Score 19.47). Forty-four episodes of pneumonia were identified. Common manifestations on the day of the diagnosis were new onset crackles (43/44, 98%), tachypnoea>25/min (42/44, 95%), and oxygen saturation <90% (41/44, 93%). Cough, purulent sputum, and pyrexia >38°C were observed in 27 (61%), 25 (57%) and 15 (34%) episodes respectively. Leucocytosis (WBC>11,000/ml) and raised CRP (>10 mg/l) were observed in 38 (86%) and 43 (97%) cases of pneumonia respectively. The area under the ROC curve for CRP was 0.827 (95% CI 0.720, 0.933). The diagnostic cut-off for CRP with an acceptable sensitivity (>0.8) was 25.60 mg/L (Youden index (J) 0.515; sensitivity 0.848; specificity 0.667). A cut-off of 64.65 mg/L had the highest diagnostic accuracy (J 0.562; sensitivity 0.636; specificity 0.926).
  
  
  CONCLUSIONS
  Patients with severe stroke frequently do not manifest key diagnostic features of pneumonia such as pyrexia, cough and purulent sputum early in their illness. The most common signs in this group are new-onset crackles, tachypnoea and hypoxia. Our results suggest that a CRP >25 mg/L should prompt investigations for pneumonia while values >65 mg/L have the highest diagnostic accuracy to justify consideration of this threshold as a diagnostic marker of post-stroke pneumonia.
authors.affiliation: Stoke Stroke Research Group, University Hospitals of North Midlands, Stoke-on-Trent, United Kingdom.
authors.forename: Anushka
authors.initials: A
authors.lastname: Warusevitane
authors.affiliation: Stroke Unit, Taunton and Somerset NHS Trust, Taunton, United Kingdom.
authors.forename: Dumin
authors.initials: D
authors.lastname: Karunatilake
authors.affiliation: Health Services Research Unit, Keele University, Stoke-on-Trent, United Kingdom.
authors.forename: Julius
authors.initials: J
authors.lastname: Sim
authors.affiliation: Stroke and Vascular Research Centre, University of Manchester, Salford Royal NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom.
authors.forename: Craig
authors.initials: C
authors.lastname: Smith
authors.affiliation: Stoke Stroke Research Group, University Hospitals of North Midlands, Stoke-on-Trent, United Kingdom.|Health Services Research Unit, Keele University, Stoke-on-Trent, United Kingdom.
authors.forename: Christine
authors.initials: C
authors.lastname: Roffe
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002097:C-Reactive Protein / Q000378:metabolism*; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D008297:Male; D011014:Pneumonia / Q000097:blood / Q000175:diagnosis*; D012372:ROC Curve; D020521:Stroke / Q000097:blood*
chemical_list: D002097:C-Reactive Protein