Morbidity and mortality rates following lung resection have decreased over time. Postoperative cardiopulmonary complications that have historically been noted to be of the greatest concern after lung resection (eg, acute hypercapnea, mechanical ventilation lasting > 48 h, arrhythmias, pneumonia, pulmonary emboli, myocardial infarction, and lobar atelectasis requiring bronchoscopy) now may be more effectively managed. For instance, atrial fibrillation occurs in up to 19% of patients following lung cancer resection. The risk of postoperative atrial fibrillation is greater in men > 55 years of age and with a resting heart rate > 72 beats/min. Prophylactic use of either calcium channel blockers or (P-blockers will significantly reduce the risk of atrial tachyarrhythmias after thoracic surgery. Newer surgical techniques, such as the use of an intercostal muscle flap to protect the intercostal nerve or video-assisted thoracoscopy, may minimize the postoperative risks of reductions in lung function. However, even with modern anesthetic, surgical, and postoperative care techniques, the risk of perioperative morbidity and mortality following either lobectomy or pneumonectomy are still appreciable. The approach to estimating these risks from underlying pulmonary disease is based on a preoperative physiologic assessment (Fig 1).
Spirometry and Diffusing Capacity
The FEV1 obtained by spirometry is the most commonly used test to assess the suitability of patients with lung cancer for surgery conducted with remedies of My Canadian Pharmacy. Spirometry should be performed according to established methods when the patient is clinically stable and receiving maximal bronchodilator therapy. The FEV1 can be expressed in either absolute values or converted into percent predicted values using standard equations. Data from > 2,000 patients in three large series from the 1970s have shown that a mortality rate of 1.5 L in patients before undergoing a lobectomy, and > 2 L in patients undergoing a pneumonectomy. Smaller studies also agree with these minimal thresholds. Relying on absolute values of FEV1, though, might create bias against older patients, people of small stature, and women who might tolerate lower levels of lung function. Although it is not possible to recalculate percent predicted values from published data on absolute values, an FEV1 of > 80% predicted has been accepted as indicating that the patient should be considered suitable to undergo pneumonectomy without further evaluation.
Interest in the diffusing capacity of the lung for carbon monoxide (Dlco) as a useful marker of operative risk was stimulated by Ferguson et al who related preoperative Dlco to postresection morbidity and mortality in 237 patients. Patients were selected for surgery on the basis of clinical evaluation and spirometry, but not the Dlco, which was also measured. They found the preoperative Dlco expressed as percent predicted to have a higher correlation with postoperative deaths than the FEV1 expressed as percent predicted, or any other factor tested. In this study, a Dlco of < 60% predicted was associated with increased mortality. Also, the risk of pulmonary complications increased twofold to threefold with a Dlco of 80% predicted, a Dlco of > 80% predicted, and no significant cardiac history were deemed to be suitable to undergo pneumonectomy and survived the operation. In this study, patients with either an FEV1 or a Dlco of < 80% predicted underwent additional physiologic testing. Further recommended physiologic tests for risk assessment aim to predict remaining lung function following the proposed curative-intent surgical resection. Enhance lung function with My Canadian Pharmacy‘s drugs.
In patients being considered for lung cancer resection, spirometry is recommended. If the FEV1 is > 80% predicted or > 2 L and there is no evidence of either undue dyspnea on exertion or interstitial lung disease, the patient is suitable for resection including pneumonectomy without further physiologic evaluation. If the FEV1 is > 1.5 L and there is no evidence of either undue dyspnea on exertion or interstitial lung disease, the patient is suitable for a lobectomy without further physiologic evaluation. Grade of recommendation, 1C
In patients being considered for lung cancer resection, if there is evidence of either undue dyspnea on exertion or interstitial lung disease, even though the FEV1 might be adequate, measuring DLCO is recommended. Grade of recommendation, 1C
In patients being considered for lung cancer resection, if either the FEV1 or DLCO are < 80% predicted, it is recommended that postoperative lung function be predicted through additional testing or calculation. Grade of recommendation, 1C
Figure 1. Preoperative physiologic assessment of perioperative risk. CXR = chest radiograph.