Analyzing lung crackle sounds: stethoscopes and beyond

Excerpt

Assessing the pulmonary function by physical examination is as old as the field of respiratory medicine. In 1819 the French physician René-Théophile-Hyacinthe Laennec (1781–1826) published his milestone book De l’Auscultation Médiate ou Traité du Diagnostic des Maladies des Poumons et du Coeur introducing the stethoscope as a diagnostic tool for the bedside assessment of respiration [1]. Even today, the stethoscope represents a symbol for physicians of all specialties. Despite all technical advances in recent years, auscultation provides both useful physiological information and close patient–physician interaction. Although auscultation is considered to be a very useful bedside tool, its major limitations are high interobserver variability, difficult description and documentation of findings, and the high dependency on individual expertise in acquiring and interpreting auscultation findings. Obtaining and interpreting lung sounds and especially adventitious sounds are a true art [2]. Secondary to its role in routine physical examination, the analysis of lung sounds can be used in the intensive care setting to gather information about the performance and efficiency of mechanical ventilation prior to or instead of more invasive radiological procedures like chest X-rays or computer tomography (CT). …