If you have asthma, COPD, pulmonary fibrosis, bronchiectasis, emphysema, or another lung condition and are preparing for surgery, your doctor may recommend pulmonary function testing (PFT) or spirometry before the operation.
Many patients wonder why a breathing test is necessary when the surgery may have nothing to do with the lungs.
The reason is simple: anesthesia, surgery, pain medicines, reduced mobility, and the surgical procedure itself can place additional demands on the respiratory system. Knowing how well your lungs are functioning before surgery can help your medical team identify potential risks and, when necessary, improve your lung condition before the operation.
What Are PFTs and Spirometry?
Pulmonary function tests (PFTs) are a group of tests used to assess how well the lungs are working. Spirometry is one of the most commonly performed pulmonary function tests.
Spirometry measures how much air you can breathe out and how quickly you can blow the air out. It can help identify airflow obstruction and assess conditions such as asthma and COPD.
Depending on the patient’s condition, a more complete PFT may also include measurements of lung volumes and diffusing capacity (DLCO), which provides information about how effectively oxygen passes from the lungs into the blood.
Why Is Spirometry Important Before Surgery?
The purpose of preoperative lung testing is not simply to produce a number.
It helps the doctor understand your respiratory reserve—in other words, how much breathing capacity your lungs have before they are exposed to the additional stress of surgery.
This information can be particularly useful when a patient already has a known lung disorder or significant respiratory symptoms.
A preoperative pulmonary assessment may help doctors:
- Identify previously unrecognized airflow limitation
- Assess the severity of an existing lung condition
- Determine whether the lung disease is adequately controlled
- Identify patients who may need optimization before surgery
- Help estimate the risk of postoperative breathing problems
- Decide whether additional pulmonary testing is necessary
- Assist the anesthesia and surgical teams in planning perioperative care
Preoperative pulmonary assessment is particularly relevant in patients with established respiratory disease and those undergoing thoracic or upper abdominal surgery.
Does Every Patient Need Spirometry Before Surgery?
No.
This is an important point.
Spirometry is not automatically required before every surgical procedure simply because a patient is having an operation.
The need for PFTs depends on several factors, including:
- The type and extent of surgery
- Whether the operation involves the chest or upper abdomen
- Existing lung disease
- Shortness of breath or exercise limitation
- Smoking history
- Abnormal findings on examination or previous investigations
- The patient’s overall health and functional capacity
- Whether the results are likely to change management
A careful medical history and physical examination remain central to preoperative risk assessment. Additional tests should be requested when they provide useful information for the individual patient.
Which Patients With Lung Disease May Benefit From PFTs Before Surgery?
Your doctor may consider pulmonary function testing if you have conditions such as:
COPD or emphysema
Patients with COPD may have reduced airflow and limited respiratory reserve. Spirometry can help determine the degree of airflow limitation and whether the condition is adequately controlled before surgery.
Asthma
If asthma is poorly controlled, surgery may be more difficult from a respiratory standpoint. Assessing lung function can help identify airflow limitation and may assist in optimizing treatment before an elective procedure.
Pulmonary fibrosis or interstitial lung disease
Patients with interstitial lung disease may have abnormalities in lung volumes and gas transfer. A complete PFT, including DLCO when appropriate, can provide additional information about pulmonary reserve.
Bronchiectasis
Patients with bronchiectasis may have chronic cough, sputum production, recurrent infections, and abnormal lung function. Preoperative assessment can help determine whether the respiratory condition is stable before surgery.
Previous major lung surgery or significant lung damage
If part of the lung has previously been removed or there is significant structural lung disease, pulmonary function testing can provide useful information about the remaining lung function.
What If the PFT Is Abnormal?
An abnormal PFT does not automatically mean that surgery cannot be performed.
This is a common concern among patients.
Instead, an abnormal result may prompt the doctor to look more closely at the cause and determine whether the patient’s lung condition can be optimized before surgery.
Depending on the situation, this may involve:
- Adjusting inhaler treatment
- Treating an active respiratory infection
- Improving asthma or COPD control
- Assessing oxygen requirements
- Encouraging smoking cessation
- Assessing exercise capacity
- Considering pulmonary rehabilitation
- Obtaining additional investigations when indicated
The goal is not simply to decide whether a patient can or cannot have surgery. The goal is to understand and reduce avoidable respiratory risks wherever possible.
Is Spirometry Enough?
Not always.
Spirometry provides important information about airflow, but some patients require a more complete assessment.
Depending on the clinical situation, a doctor may consider:
Full pulmonary function testing: This may include lung volumes and DLCO.
Six-minute walk test: This can provide information about exercise tolerance and oxygenation.
Cardiopulmonary exercise testing: In selected patients, particularly when major lung surgery is being considered, more detailed exercise testing may be required.
Chest imaging: Previous CT scans or chest X-rays may provide important information about the underlying lung disease.
The appropriate tests depend on the patient’s condition and the planned operation.
PFT Before Lung Surgery Is Especially Important
Patients who are being considered for lung resection, such as surgery for lung cancer, require particularly careful assessment of their remaining lung function.
Spirometry and DLCO are important components of this evaluation. In patients with reduced lung function, doctors may calculate predicted postoperative lung function and, when necessary, perform additional exercise testing to better understand the risk of surgery.
This assessment helps the surgical team determine whether the patient has sufficient respiratory reserve for the planned procedure and whether an alternative treatment approach should be considered.
Can PFT Help Make Surgery Safer?
A PFT itself does not make surgery safer.
Its value is in providing information that can influence medical decision-making.
For example, if testing reveals poorly controlled obstructive lung disease, there may be an opportunity to optimize treatment before an elective operation.
Similarly, if testing suggests significantly reduced pulmonary reserve, the medical team may decide that additional assessment or specific perioperative precautions are appropriate.
Preoperative evaluation provides an opportunity to identify underlying disease, optimize medical conditions, and develop an individualized plan for the patient’s surgery and anesthesia.
What Should Patients Tell Their Doctor Before PFT?
Before pulmonary function testing, tell the doctor or testing staff about:
- Your current lung disease
- All inhalers and respiratory medications you use
- Recent chest infections
- Recent surgery or significant medical problems
- Oxygen use
- Smoking history
- Any significant breathlessness or chest symptoms
You may also be given specific instructions about whether certain inhalers or medications should be withheld before testing. Do not stop a prescribed medication unless your doctor or testing center specifically instructs you to do so.
The Chest Clinic – Dr. Javed Husain & Associates, Karachi, Pakistan
At The Chest Clinic – Dr. Javed Husain & Associates, Karachi, Pakistan, patients with respiratory disorders can be assessed for lung function and their suitability for surgery based on their individual clinical condition.
Dr. Javed Husain provides specialist care in respiratory medicine, including evaluation of chronic lung diseases, pulmonary function assessment, and preoperative pulmonary evaluation when required.
If you have a lung disorder and are planning surgery, discussing your respiratory condition with a pulmonary specialist before the operation can help ensure that your lung health is properly assessed and optimized.
For appointments and information call +923018479066, +923293364949, or email us at connect@thechestclinic.pk