Preparing a patient for spirometry involves a combination of pre-appointment instructions, day-of screening, and in-the-moment coaching that together determine whether the results are accurate and usable. Skipping any step can produce unreliable numbers that lead to misdiagnosis or unnecessary repeat testing. Here’s what thorough preparation looks like from start to finish.
Pre-Appointment Instructions
Preparation starts before the patient arrives. When scheduling the test, give patients a clear list of restrictions so they have time to plan. The key instructions, drawn from National Heart, Lung, and Blood Institute guidelines, are straightforward:
- No smoking on the day of the test. Smoking temporarily narrows airways and irritates the lining of the lungs, both of which reduce airflow measurements.
- No alcohol for at least 4 hours before the test. Alcohol can relax airway muscles and alter breathing patterns enough to skew results.
- Avoid large meals in the hours before testing. A full stomach pushes the diaphragm upward, limiting how deeply the lungs can expand.
- Wear loose, comfortable clothing that doesn’t squeeze the chest or abdomen. Tight waistbands, compression garments, or restrictive bras can physically limit a full inhalation.
If bronchodilator responsiveness testing is planned, patients also need guidance on withholding inhaler medications. Short-acting bronchodilators are typically held for 4 to 6 hours, and long-acting bronchodilators for 12 to 24 hours, depending on the specific medication and the ordering provider’s instructions. Make sure patients understand they should not skip medications without being told to do so, since the test may be designed to measure lung function while on treatment.
Screening for Contraindications
Spirometry requires forceful exhalation, which temporarily spikes pressure inside the chest, abdomen, skull, and eyes. That pressure is harmless for most people but can be dangerous for patients with certain recent medical events. The 2019 ATS/ERS spirometry standards list these as relative contraindications, meaning the test isn’t automatically ruled out but the risks need to be weighed carefully.
Before testing, screen for the following:
- Heart-related concerns: heart attack within the past week, severe high or low blood pressure, significant irregular heart rhythms, uncontrolled heart failure, unstable blood clots in the lungs, or uncontrolled pulmonary hypertension.
- Head and eye concerns: brain aneurysm, brain surgery within 4 weeks, recent concussion with ongoing symptoms, or eye surgery within 1 week.
- Ear and sinus concerns: sinus or middle ear surgery or infection within 1 week.
- Chest and abdominal concerns: active collapsed lung (pneumothorax), chest surgery within 4 weeks, abdominal surgery within 4 weeks, or late-term pregnancy.
- Infection control: active or suspected tuberculosis, other transmissible respiratory infections, coughing up blood, heavy secretions, or visible oral lesions or bleeding.
A quick verbal checklist at intake catches most of these. If a patient flags any item, the ordering provider decides whether to proceed, postpone, or cancel.
Collecting Accurate Baseline Data
Spirometry results are compared against predicted normal values that are calculated from the patient’s age, sex, height, and race or ethnicity. If any of these inputs are wrong, the predicted values will be wrong, and a normal result might look abnormal (or vice versa).
Height is the single most influential variable. Taller people have larger lungs, so even a one-inch error shifts the predicted range meaningfully. Measure standing height without shoes at the time of the test rather than relying on self-reported numbers. For patients who cannot stand upright, arm span can serve as a proxy. Weight and body mass index also influence spirometry indices, particularly in patients with chronic lung conditions, so recording an accurate weight matters too.
Explaining the Maneuver Before You Begin
Many patients have never done spirometry before, and the forced exhalation feels unnatural. Taking 60 seconds to demonstrate and explain the maneuver dramatically improves the quality of the first few attempts.
A clear, plain-language script covers three phases. Something like: “Start with normal breathing. Then take a huge breath in until your lungs are completely full. Blast the air out as hard and fast as you can, and keep blowing until you feel completely empty and can’t push out any more air. Then take another big, fast, full breath back in.” Demonstrating the blast yourself, or even miming the posture and effort involved, helps patients understand the intensity required. This isn’t gentle breathing. It’s a maximal effort, and patients need to know that before the mouthpiece goes in.
Coaching During the Test
Preparation doesn’t end once the test starts. Active, real-time coaching is one of the biggest factors in getting usable results.
The most common problems and how to address them:
- Hesitant start: Some patients inhale fully but then pause before exhaling. Synchronize your command to “blast” so it lands just before they finish inhaling. That way the exhalation follows the inhalation without a gap.
- Vocalization during exhalation: If a patient grunts or makes a sound while blowing out, the throat partially closes and restricts airflow. Demonstrate the difference between exhaling with and without vocalization, and remind them to keep the throat open.
- Stopping exhalation too early: Patients often feel “empty” well before they’ve actually exhaled long enough. Verbal countdown cues like “two more seconds, one more second” encourage them to push through. Another technique is to instruct patients to pull their abdominal muscles inward near the end of exhalation. This serves as a distraction that keeps them blowing rather than cutting the effort short.
Your tone matters as much as the words. Sharp, energetic commands (“Blast! Keep going! Keep going! Push push push!”) paired with tactile cues like a hand signal can motivate a level of effort that calm, measured instructions simply cannot. Think of it as coaching an athlete through a sprint, not guiding someone through a meditation.
Positioning and Comfort
Patients should sit upright with both feet flat on the floor, unless standing is preferred or clinically indicated. A chair with no wheels is safest, since forceful exhalation can occasionally cause lightheadedness. Dentures that fit well can stay in, as they help maintain a seal around the mouthpiece. Loose dentures should come out, since they can obstruct the mouthpiece or shift during the blast.
Place a nose clip to seal the nostrils before each attempt. Air leaking through the nose reduces measured volume and makes results unreliable. Make sure the mouthpiece sits between the teeth with lips sealed tightly around it, with no gaps at the corners of the mouth.
How Many Attempts to Expect
Spirometry requires a minimum of three acceptable, reproducible efforts. In practice, most patients need four to eight attempts to produce three good ones. Let patients rest between efforts, typically 30 seconds to a minute, to avoid fatigue or dizziness. If a patient becomes lightheaded, give them as much time as they need before continuing. Forced exhalation transiently raises intrathoracic pressure and can cause brief drops in blood pressure, so mild lightheadedness is common and usually resolves quickly with rest.
Setting expectations up front (“This test usually takes about 15 to 20 minutes, and you’ll blow into the tube several times”) reduces frustration and helps patients pace their effort rather than burning out on the first three tries.