Name of the Procedure:

Plethysmography for determination of lung volumes and, when performed, airway resistance

Summary

Plethysmography is a non-invasive test that measures the volume of air in your lungs, including the amount you can inhale and exhale, as well as the air left in your lungs after exhaling. When necessary, it can also measure airway resistance. This test is typically performed using a body plethysmograph, a sealed, transparent box you sit in during the procedure.

Purpose

Plethysmography helps diagnose and monitor conditions that affect lung function, such as asthma, chronic obstructive pulmonary disease (COPD), and restrictive lung disease. By determining lung volumes and airway resistance, it aids in assessing the severity of lung disorders and the effectiveness of treatments.

Indications

• Shortness of breath
• Chronic cough
• Unexplained wheezing
• Ongoing respiratory issues despite treatment
• Monitoring response to therapy in known lung conditions
• Preoperative assessment for patients undergoing surgery

Preparation

• Avoid eating a large meal before the test.
• Wear comfortable, loose-fitting clothing.
• Follow any specific instructions provided by your healthcare provider, which may include withholding certain medications that can affect test results.

Procedure Description

1. The patient sits in a sealed, transparent box known as a body plethysmograph.
2. A mouthpiece connected to the equipment is placed in the patient’s mouth, while the nose is clipped shut.
3. The patient performs a series of breathing maneuvers as instructed, such as breathing normally, taking deep breaths, and panting.
4. The equipment measures changes in pressure and volume to calculate lung volumes and airway resistance.

Duration

The procedure typically takes about 20 to 40 minutes.

Setting

Plethysmography is usually performed in a hospital pulmonary function lab or an outpatient clinic equipped with the necessary equipment.

Personnel

• Respiratory therapist or pulmonary function technician
• Pulmonologist or supervising physician

Risks and Complications

• The procedure is generally safe with minimal risks.
• Some patients may experience dizziness, shortness of breath, or mild claustrophobia due to the enclosed space.
• Rarely, the test may induce coughing spells or asthma attacks in susceptible individuals.

Benefits

• Provides detailed information about lung volumes and airway resistance.
• Helps accurately diagnose and monitor lung conditions.
• Aids in the appropriate management and treatment planning for respiratory disorders.
• Results are typically available shortly after the test, allowing for timely decision-making.

Recovery

• The patient can usually resume normal activities immediately after the procedure.
• Follow any specific instructions provided by your healthcare provider.
• Schedule follow-up appointments as recommended to discuss the results and any further steps.

Alternatives

• Spirometry: A simpler test that measures airflow but may not provide as detailed information as plethysmography.
• Gas dilution or nitrogen washout tests: Alternative methods to measure lung volumes but often less comprehensive.
• Imaging tests like chest X-rays or CT scans: Provide structural information but not functional details.

Patient Experience

• The patient may feel momentary discomfort from the mouthpiece and nasal clip.
• Breathing maneuvers may cause slight shortness of breath or lightheadedness.
• Efforts will be made to ensure patient comfort and handle any anxiety during the procedure.