What testing should be performed before a lobectomy (surgical removal of a lung lobe)?

From the Guidelines

Before a lobectomy, patients should undergo a preoperative physiologic assessment starting with cardiovascular evaluation and spirometry to measure FEV1 and diffusing capacity for carbon monoxide (DLCO), as recommended by the American College of Chest Physicians evidence-based clinical practice guidelines 1. The assessment of surgical candidacy for lobectomy involves several key tests to minimize complications and ensure the best possible outcomes.

• Pulmonary function tests (PFT) with spirometry and diffusion capacity are crucial to evaluate respiratory reserve, with a focus on FEV1 and DLCO values.
• The predicted postoperative (PPO) lung functions should be calculated, and if the % PPO FEV1 and % PPO DLCO values are both ≥ 60%, the patient is considered at low risk of anatomic lung resection, and no further tests are indicated 1.
• For patients with % PPO FEV1 or % PPO DLCO between 60% and 30% predicted, a low technology exercise test should be performed as a screening test, and if the performance is satisfactory, patients are regarded as at low risk of anatomic resection 1.
• A cardiopulmonary exercise test is indicated when the PPO FEV1 or PPO DLCO (or both) are < 30% or when the performance of the stair-climbing test or the shuttle walk test is not satisfactory, with a peak oxygen consumption (O2peak) < 10 mL/kg/min or 35% predicted indicating a high risk of mortality and long-term disability for major anatomic resection 1.
• Systematic measurement of DLCO is recommended in all lung resection candidates, regardless of their preoperative level of FEV1, as it has been shown to be a valid predictor of major morbidity even in patients without airflow limitation 1.
• The value of DLCO has been associated with long-term survival and residual quality of life, making it a critical component of the preoperative assessment 1.
• Other tests such as arterial blood gas analysis, cardiac evaluation through ECG and echocardiography, imaging studies (chest CT scan, PET scan, brain MRI), laboratory tests (complete blood count, comprehensive metabolic panel, coagulation studies), and bronchoscopy may be performed as necessary to complete the preoperative evaluation 1.

From the Research

Preoperative Testing for Lobectomy

The following tests are recommended before performing a lobectomy:

• Measurements of FEV1 (forced expiratory volume in 1 second) and DLco (carbon monoxide lung diffusion capacity) should be taken 2
• If either FEV1 or DLco is < 80% of the predicted value, an exercise test with VO2 max (oxygen consumption during maximal exercise) measurement should be performed 2
• The exercise test with VO2 max measurement may be replaced with other tests such as the shuttle walk test and the stair climbing test 2
• Patients considered for lobectomy should be able to climb 3 flights of stairs (12 m) 2

Predictors of Pulmonary Complications

The following are predictors of pulmonary complications after lobectomy:

• Dlco (odds ratio 1.03, p=0.003) and FEV1 (odds ratio 1.04, p=0.003) are significant predictors of pulmonary complications for patients undergoing thoracotomy 3
• However, Dlco and FEV1 are not significant predictors of pulmonary complications for patients undergoing thoracoscopy 3
• Diabetes is a predictor of the composite of all-cause morbidity and postoperative home oxygen use 4

Outcomes of Lobectomy in High-Risk Patients

Lobectomy can be safely performed in select patients considered to be high risk for resection by pulmonary function tests:

• A study found that lobectomy can be performed in patients with a predicted postoperative DlCO less than or equal to 40% with no operative mortality and a 5-year survival rate of 69% 4
• However, additional criteria are needed to assess risk in these patients 4

Pulmonary Function Changes After Lobectomy

The extent of pulmonary resection can affect postoperative pulmonary function:

• A study found that forced vital capacity (FVC) loss after lobectomy was significantly greater than after segmentectomy or wedge resection 5
• Forced expiratory volume in 1 second (FEV1) loss after lobectomy was similar to segmentectomy but greater than after wedge resection 5
• Diffusing capacity of the lungs for carbon monoxide (DLCO) loss was similar among the three groups 5