Related Experiment Video
Updated: Oct 18, 2026
Protocol and Guidelines for Point-of-Care Lung Ultrasound in Diagnosing Neonatal Pulmonary Diseases Based on International Expert Consensus
Published on: March 6, 2019
Diagnostic value of tachypnoea in pneumonia defined radiologically
M Palafox1, H Guiscafré, H Reyes
1Research Unit on Epidemiology and Health Services, Mexican Social Security Institute, Centro Médico Nacional Siglo XXI, Unidad de Congresos, Bloque B, 4o. Piso, Avenida Cuauhtémoc 330, Col. Doctores, Mexico 06725 DF.
Insights
Tachypnoea is a useful indicator for diagnosing childhood pneumonia, especially when used alone. Its diagnostic accuracy, however, is lower in the initial stages of illness and in children with low weight for age.
Area of Science:
- Pediatrics
- Diagnostic Accuracy
- Infectious Diseases
Background:
- Pneumonia remains a leading cause of childhood mortality globally.
- Early and accurate diagnosis is crucial for effective treatment and improved outcomes.
- Tachypnoea (rapid breathing) is a common clinical sign associated with respiratory infections in children.
Purpose of the Study:
- To determine if the diagnostic accuracy of tachypnoea for pneumonia varies with patient age, nutritional status, or disease duration.
- To evaluate tachypnoea's sensitivity and specificity as a standalone diagnostic tool versus in combination with other clinical signs.
Main Methods:
- A diagnostic accuracy study involving 110 children with acute respiratory infection was conducted.
- Chest roentgenogram served as the gold standard for pneumonia diagnosis.
- Sensitivity, specificity, and correct classification rates of tachypnoea were calculated overall and stratified by age, nutritional status (weight for age), and disease duration.
Main Results:
- Tachypnoea alone demonstrated 74% sensitivity and 67% specificity for pneumonia diagnosis.
- Combining tachypnoea with other signs increased specificity to 84% but did not significantly improve overall correct classification.
- Diagnostic accuracy was notably lower in children with disease duration less than three days (55% sensitivity, 64% specificity) and in those with low weight for age (83% sensitivity, 48% specificity).
- No significant variations in sensitivity and specificity were observed across different age groups.
Conclusions:
- Tachypnoea is a valuable standalone clinical sign for identifying childhood pneumonia, with consistent accuracy across age groups.
- Its diagnostic utility is diminished in the early phase of illness (first three days) and in children with malnutrition.
- While combining tachypnoea with other signs enhances specificity, it may not substantially improve the overall diagnostic yield.
Objective:
To evaluate whether sensitivity and specificity of tachypnoea for the diagnosis of pneumonia change with age, nutritional status, or duration of disease.
Methods:
Diagnostic testing of 110 children with acute respiratory infection, 51 of whom presented with tachypnoea. The gold standard was a chest roentgenogram. Thirty five children had a radiological image of pneumonia; 75 were diagnosed as not having pneumonia. Sensitivity, specificity, and percentage of correct classification of tachypnoea, by itself or in combination with other clinical signs for all children, by age groups, nutritional status, and disease duration were calculated.
Results:
Tachypnoea as the sole clinical sign showed the highest sensitivity (74%) and a specificity of 67%; 69% of cases were classified correctly. Sensitivity was reduced when other clinical signs were combined with tachypnoea, and there was no significant increase in correct classification, although specificity increased to 84%. In children with a disease duration of less than three days, tachypnoea had a lower sensitivity and specificity (55% and 64%, respectively), and a lower percentage of correct classification (62%). In children with low weight for age (< 1 Z-score), tachypnoea had a sensitivity of 83%, a specificity of 48%, and 60% correct classification. Sensitivity and specificity did not vary with age groups.
Conclusions:
Tachypnoea used as the only clinical sign is useful for identifying pneumonia in children, with no significant variations for age. In children with low weight for age, tachypnoea had higher sensitivity, but lower specificity. However, during the first three days of disease, the sensitivity, specificity, and percentage of correct classification were significantly lower.
Related Concept Videos
01:30Pneumonia III: Complications and Assessment
01:23Assessment of Respiration
Subjective Assessment: Nurses interview the patient to gather information directly during the subjective assessment. It includes questions about the individual's medical history, medications, and symptoms, focusing on past respiratory conditions like asthma or COPD,...
01:29Pneumonia II: Pathophysiology
01:14Atypical Pneumonia
01:30Pneumonia I: Introduction
Risk Factors
Various factors influence the likelihood of developing pneumonia. Age plays a crucial role, with infants, children under two, and individuals over 65 at increased risk due to their...
01:29Pneumonia I: Introduction