Chapter 17: Assessment of Respiratory Function

Assessment of Respiratory Function explains the mechanics of ventilation, including the roles of the diaphragm and intercostal muscles, air pressure variances, airway resistance, and lung compliance, while distinguishing between pulmonary diffusion and perfusion. The text delves into gas exchange processes, detailing the partial pressure of gases, oxygen transport via the oxyhemoglobin dissociation curve, carbon dioxide transport, and the complex neurologic control of ventilation involving central and peripheral chemoreceptors. Significant attention is given to gerontologic considerations, highlighting age-related changes such as decreased alveolar elasticity, reduced vital capacity, and increased residual volume. The nursing assessment framework is rigorously outlined, starting with a health history that evaluates common symptoms like dyspnea (including orthopnea and paroxysmal nocturnal dyspnea), cough, sputum production, chest pain, and hemoptysis, alongside risk factors such as smoking (measured in pack-years) and genetic history. The physical examination section covers inspection of chest configuration (identifying deformities like barrel chest, pectus excavatum, and kyphoscoliosis) and respiratory patterns (such as Cheyne-Stokes, Biot’s, and Kussmaul’s respirations), palpation for tracheal deviation, respiratory excursion, and tactile fremitus, and percussion to detect resonance or dullness. Auscultation is detailed extensively, differentiating normal breath sounds (vesicular, bronchovesicular, bronchial) from adventitious sounds (crackles, wheezes, rhonchi, friction rubs, stridor) and abnormal voice sounds (bronchophony, egophony, whispered pectoriloquy). The chapter concludes with a thorough overview of diagnostic evaluations, including pulmonary function tests (measuring tidal volume, vital capacity, and inspiratory force), arterial blood gas analysis, pulse oximetry, end-tidal carbon dioxide monitoring, and imaging modalities like chest x-rays, CT scans, MRI, pulmonary angiography, and V/Q scans. Finally, it addresses invasive endoscopic procedures such as bronchoscopy, thoracoscopy, and thoracentesis, emphasizing the nurse's role in pre-procedure preparation and post-procedure monitoring for complications like pneumothorax, aspiration, and bleeding.