Diagnostic Services -- Plantation, FL

Lung Function Testing for Asthma

Precise breathing tests are the foundation of effective asthma care. At Advanced Asthma Clinic, Dr. Frank Hull uses a full suite of pulmonary function tests to accurately diagnose your asthma, measure its severity, and guide the right treatment -- including eligibility for biologic therapies.

Schedule a Test Call 954-522-7226

Why Lung Function Testing Matters

Asthma is a complex, variable condition. Symptoms such as coughing, wheezing, and shortness of breath can overlap with many other conditions. Without objective lung function measurements, treatment decisions are based on guesswork -- and patients may receive therapy that is either insufficient or more aggressive than necessary.

Lung function tests give Dr. Hull measurable data: how open your airways are, how inflamed they are, and whether your lungs respond to bronchodilator medication. This data directly determines which treatments -- including advanced biologic therapies -- may be right for you. Always consult your physician before making any changes to your treatment plan.

Did you know? A FeNO level above 50 ppb suggests significant eosinophilic airway inflammation -- a key indicator for certain biologic therapies. Many patients don't know their FeNO level. A single breath test can change your treatment trajectory.

Tests We Perform

Advanced Asthma Clinic offers a comprehensive range of pulmonary function tests in our Plantation, FL office. Most tests are non-invasive and completed within a single visit.

Spirometry -- The Gold Standard Breathing Test

Spirometry is the most widely used lung function test and the cornerstone of asthma diagnosis. During the test, you breathe into a mouthpiece connected to a spirometer, which measures two key values:

  • FEV1 (Forced Expiratory Volume in 1 second) -- how much air you can forcefully exhale in one second. Reduced FEV1 is a hallmark of obstructive airway disease.
  • FVC (Forced Vital Capacity) -- the total volume of air you can exhale after a deep breath.
  • FEV1/FVC ratio -- values below 0.70 confirm airflow obstruction consistent with asthma or COPD.

Spirometry also guides asthma severity classification (mild, moderate, severe) under GINA guidelines, which directly informs treatment step-up decisions. The test is quick, safe, and requires no needles or sedation.

Bronchodilator Reversibility Testing

After baseline spirometry, you inhale a short-acting bronchodilator (such as albuterol), and spirometry is repeated 15 minutes later. A significant improvement in FEV1 -- typically 12% or more and at least 200 mL -- confirms reversible airflow obstruction, which is characteristic of asthma rather than fixed airway disease such as COPD.

This distinction is clinically important. It shapes both diagnosis and the choice of long-term therapy.

FeNO (Fractional Exhaled Nitric Oxide) -- Airway Inflammation Measurement

FeNO is a breath test that measures nitric oxide levels in your exhaled air -- a direct marker of eosinophilic (type 2 allergic) airway inflammation. You breathe steadily into a handheld device at a constant flow rate. The result is available in minutes.

  • FeNO < 25 ppb: Low inflammation -- eosinophilic asthma unlikely
  • FeNO 25-50 ppb: Intermediate -- further evaluation warranted
  • FeNO > 50 ppb: High eosinophilic inflammation -- may indicate eligibility for biologic therapy (dupilumab, mepolizumab, benralizumab)

FeNO testing is particularly valuable for patients with difficult-to-control asthma who may benefit from biologic therapies. It is also used to monitor response to inhaled corticosteroid therapy over time.

Bronchoprovocation -- Methacholine Challenge Test

Some patients have symptoms consistent with asthma but show normal spirometry results. In these cases, bronchoprovocation testing confirms or rules out airway hyperresponsiveness -- the defining physiological feature of asthma.

During a methacholine challenge, you inhale progressively increasing concentrations of methacholine (a bronchospasm-inducing agent). Spirometry is measured after each dose. A significant drop in FEV1 at a low concentration confirms airway hyperresponsiveness consistent with asthma.

This test is conducted under close medical supervision at our Plantation clinic. Dr. Hull will review your clinical history and current lung function before ordering this test. It is contraindicated in patients with severe baseline airflow obstruction.

Diffusing Capacity (DLCO) -- Oxygen Transfer Efficiency

The DLCO test measures how efficiently your lungs transfer oxygen from inhaled air into your bloodstream. You breathe in a small, safe amount of carbon monoxide (used as a tracer gas) and hold your breath briefly. The exhaled concentration reveals how well gas exchange is occurring across the alveolar membrane.

DLCO is particularly useful when emphysema or interstitial lung disease may coexist with asthma, and in distinguishing between different causes of exercise-induced breathlessness.

Peak Flow Monitoring -- Tracking Asthma Day to Day

Peak expiratory flow (PEF) measures the maximum speed of exhalation. While less comprehensive than full spirometry, peak flow meters are inexpensive, portable, and ideal for home monitoring. Dr. Hull may prescribe a personal peak flow meter and written action plan to help you detect early signs of an asthma flare-up before symptoms become severe.

A drop in your personal best PEF of 20% or more typically signals worsening airway obstruction requiring action -- even when you feel only mildly symptomatic.

How Results Guide Your Asthma Treatment

At Advanced Asthma Clinic, Dr. Hull integrates your lung function data with your symptom history, blood biomarkers (eosinophil count, IgE), and allergy profile to build a personalized treatment plan. Here is how test results translate into clinical decisions:

Confirming the Diagnosis

Spirometry with bronchodilator reversibility confirms asthma and rules out other causes of breathlessness such as vocal cord dysfunction or fixed airway obstruction.

Classifying Severity

FEV1 percentage predicted determines mild, moderate, or severe asthma classification under GINA guidelines -- driving step-up and step-down therapy decisions.

Biologic Therapy Eligibility

Elevated FeNO and blood eosinophil counts indicate type 2 airway inflammation -- the primary criterion for FDA-approved biologics such as mepolizumab, dupilumab, and tezepelumab.

Monitoring Progress

Serial spirometry and FeNO measurements track whether your current treatment is controlling airway inflammation and preserving lung function over time.

How to Prepare for Your Lung Function Test

Most lung function tests require minimal preparation, but following these guidelines ensures accurate, reproducible results. Always confirm specific preparation instructions with our office when scheduling.

  • Short-acting bronchodilators (albuterol): Avoid for 4-6 hours before the test unless clinically unsafe to do so.
  • Long-acting bronchodilators (salmeterol, formoterol): Avoid for 12-24 hours before the test.
  • Caffeine: Avoid coffee, tea, and energy drinks on the day of testing.
  • Smoking: Do not smoke for at least 4 hours prior to the test.
  • Clothing: Wear loose, comfortable clothing that does not restrict your chest or abdomen.
  • Food: Avoid a large meal within 2 hours of testing.
  • Methacholine challenge specifically: Avoid exercise and cold air exposure for 4 hours beforehand. Confirm all medications to hold with Dr. Hull's clinical team.

This is general guidance only. Always follow the specific instructions provided by Dr. Hull or our clinical team at the time of scheduling. Do not alter prescribed medications without physician guidance.

Pulmonary Expertise You Can Trust

Dr. Frank Hull is board-certified in Pulmonary Medicine, Critical Care, and Sleep Medicine, with over 20 years of clinical and research experience in severe asthma management. At Advanced Asthma Clinic in Plantation, FL, he combines state-of-the-art pulmonary function testing with evidence-based treatment -- including the latest biologic therapies and active clinical trial participation.

Serving patients throughout Broward County, including Fort Lauderdale, Hollywood, Davie, Sunrise, and Coral Springs.

Schedule Your Lung Function Test

Most tests are completed in a single visit. We welcome new patients and referrals throughout South Florida.

Request an Appointment Call 954-522-7226

10059 NW 1st Court, Plantation, FL 33324

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