General

Synonym/Acronym:
Pulmonary function tests (PFTs).

Rationale
To assess respiratory function to assist in evaluating obstructive versus restrictive lung disease and to monitor and assess the effectiveness of therapeutic interventions.

Patient Preparation
There are no fluid restrictions unless by medical direction. Instruct the patient to refrain from smoking tobacco or eating a heavy meal for 4 to 6 hr prior to the study. Protocols may vary among facilities. Instruct the patient to avoid bronchodilators (oral or inhalant) for at least 4 hr before the study, as directed by the health-care provider (HCP).

Normal Findings

• Normal findings, formulas used to calculate derived measurements, and interpretation of PFTs, are based on comparisons to values obtained from healthy individuals with the same physical (e.g., age, gender, height, and weight) and ethnic characteristics (where applicable) from the same general population.
• Normal respiratory volume and capacities, gas diffusion, and distribution
• No evidence of chronic obstructive pulmonary disease (COPD) or restrictive pulmonary disease

Critical Findings and Potential Interventions

• Hypoxia occurs at oxygen saturation levels less than 90%. Significant hypoxia, levels less than 85%, require immediate evaluation and treatment.

Timely notification to the requesting HCP of any critical findings and related symptoms is a role expectation of the professional nurse. A listing of these findings varies among facilities.