Early Diagnosis of Pneumonia in Severe Stroke: Clinical Features and the Diagnostic Role of C-Reactive Protein

Abstract

BackgroundAccurate 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.MethodsPatients 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.Results60 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).ConclusionPatients 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.

Oral Health, Oral Microbiota, and Incidence of Stroke-Associated Pneumonia—A Prospective Observational Study

“…Recently, it was reported that elevated serum levels of CRP could be a predictor for post-stroke disability and prognosis (46) as well as a diagnostic marker for stroke-associated pneumonia (47,48). In the present study, median CRP serum levels were found to be significantly increased in pneumonia patients from the BL investigation timepoint, reaching a plateau at 48 h and decreasing again till the 120-h investigation.…”

C-reactive protein levels in the early stage of COVID-19

“…CRP levels can activate the complement and enhance phagocytosis, thus clearing the pathogenic microorganisms invading the body. CRP levels can be used for early diagnosis of pneumonia [3], and patients with severe pneumonia had high CRP levels. It is an important index for the diagnosis and assessment of severe pulmonary infectious diseases [17].…”

“…Other sensitive indicators able to reflect lung lesion changes and disease severity had to be explored. C-reactive protein (CRP) levels can be used in the early diagnosis of pneumonia [3], and patients presenting with severe pneumonia had high CRP levels. We assessed the correlation between CRP levels, lung lesions, and disease severity to provide reference for clinical treatment.…”

Elevated C-reactive protein increases diagnostic accuracy of algorithm-defined stroke-associated pneumonia in afebrile patients

“…13 A more recent study using receiver operating characteristics analysis showed that CRP concentration >25.60 mg/l was the optimal diagnostic threshold for the diagnosis of SAP, with high sensitivity (0.85) but low specificity (0.67). 8 As the pyrexia-based CDC algorithm has high specificity but low sensitivity 7 and the CRP threshold has high sensitivity but low specificity for diagnosis of SAP, 8 we hypothesized that combining a CRP threshold criterion with the pyrexia-based algorithm would have high specificity and high sensitivity for SAP diagnosis. The objective of this study was therefore to determine if incorporating CRP !30 mg/l as an additional criterion to the existing CDC-based algorithm 7,14 would improve accuracy of SAP diagnosis using adjudicated SAP as the reference standard.…”