Physical Assessment of the Respiratory Tract II: Inspection

The normal chest configuration has an anteroposterior diameter to lateral diameter ratio of 1:2. This means the front-to-back measurement should be half the side-to-side measurement. Deviations from this ratio may indicate respiratory distress or underlying lung disease. Inspecting chest configuration is the first step in assessing respiratory health.

Barrel chest increases anteroposterior diameter due to lung overinflation, common in emphysema. Funnel chest is a lower sternum depression that can compress the heart. Pigeon chest displaces the sternum anteriorly, increasing anteroposterior diameter. Kyphoscoliosis features an elevated scapula and S-shaped spine, limiting lung expansion. Understanding these deformities helps identify respiratory system abnormal finding i inspection and percussion findings.

During inspection, observe that inspiration duration is half that of expiration, creating a 1:2 ratio. The normal adult respiratory rate ranges from 12 to 20 breaths per minute at rest. Older adults typically breathe 16 to 25 breaths per minute. Abnormal patterns like rapid, deep, or irregular breathing may indicate pathologic conditions requiring further evaluation.

Cyanosis, a late sign of hypoxemia, appears as bluish discoloration best observed in the conjunctivae, lips, palms, and under the tongue. Long-standing hypoxemia causes nail clubbing, where the angle between the nail base and tip increases to 180 degrees or more. Both findings suggest significant oxygen deprivation requiring clinical intervention.

Accessory muscles include the sternocleidomastoid, scalene, and trapezius muscles during inspiration, and the abdominal and internal intercostal muscles during expiration. These muscles provide additional respiratory support during exertion or disease conditions. Observing their use indicates whether the patient is breathing effortlessly or experiencing respiratory distress.

Increased accessory muscle use suggests the patient is working harder to breathe and may indicate respiratory distress or disease. When breathing is effortless, accessory muscles remain inactive. Observing prominent use of the sternocleidomastoid, scalene, trapezius, abdominal, or internal intercostal muscles signals compromised respiratory function requiring further assessment.

Inspecting the posterior chest reveals spinal curvatures such as kyphosis, scoliosis, and kyphoscoliosis that affect breathing mechanics. These structural abnormalities can limit lung expansion and compromise respiratory function. Posterior inspection complements anterior chest assessment to provide comprehensive understanding of musculoskeletal factors influencing the physiology of respiration i functions of the respiratory system.