Lung volume reduction surgery for a patient receiving mechanical ventilation after a complex cardiac operation

Critical Care of the Lung Volume Reduction Surgery Patient

Lung volume reduction surgery (LVRS) offers the potential to improve lung function, exercise tolerance, and quality of life for patients with advanced emphysema. At present, the specific role of this procedure in the treatment of advanced emphysema is a subject of ongoing investigation. LVRS is most commonly performed bilaterally via either median sternotomy or video thoracoscopic approach with resection of the most severely affected lung tissue to reduce the overall lung volume by 20–30%. This results in improvements in lung elastic recoil, airway conductance, chest wall, and diaphragmatic function leading to greater inspiratory and expiratory airflow, decreased hyperinflation, and improved exercise tolerance. The greatest improvement after LVRS occurs within 3–6 months after surgery. In the perioperative period, however, lung function may be compromised by surgical incisions, pain, chest tubes, retained secretions, pneumonia, and parenchymal injury associated with resection. The risks of LVRS are not insignificant, with reported mortality prior to hospital discharge ranging from 2.5 to 14%. Pulmonary complications may include respiratory failure, persistent air leaks, pneumonia, tracheobronchitis, retained secretions, atelectasis, pneumothorax, bleeding, and sternal wound infections or dehiscence. Cardiac and gastrointestinal complications are the most common extrathoracic causes of perioperative morbidity after LVRS. Although many patients have an uneventful postoperative course, patients who experience complications frequently require prolonged mechanical ventilation and intensive care. Critical care practitioners must therefore be familiar with LVRS, its potential complications, and the ICU management of LVRS patients.

Preoperative pulmonary evaluation: facts and myths

This review summarizes recent reports on preoperative pulmonary evaluation focusing on the impact on outcome in thoracic and non-thoracic surgery. Data suggest that hitherto widely accepted pulmonary function tests do not predict perioperative complications. Therefore, they may not be considered alone to decide on the patient's operability. So-called prohibitive lung function parameters should no longer be used to deny a potentially curative lung resection. A more clinically oriented, interdisciplinary approach to severely compromised patients may be best suited to discuss and solve their problems.

Early and long-term results of surgery for aneurysms of the thoracic aorta in septuagenarians and octogenarians

OBJECTIVE

The purpose of this study was to demonstrate early and long-term results of surgery for thoracic aortic aneurysm in patients over 70 years of age compared with those of patients under 70 years and to clarify the clinical problems peculiar to this subset of patients.

PATIENTS AND METHODS

Of 1157 patients who underwent surgery for thoracic aortic aneurysm from 1978 to December 1997, 261 who were 70 years or older were selected for analysis. Mean age at the time of surgery was 74.4 +/- 3.5 years. Aneurysms were atherosclerotic in 177 patients and aortic dissection in 84. Acute aortic dissection was found in 25 patients and ruptured aneurysm in 44. The control group consisted of 896 patients under 70 years. Preoperative complications such as AAA, peripheral arterial disease, emphysema, and old cerebral infraction were more common in the older group. Operative procedures consisted of replacement of the ascending aorta or hemiarch in 51 patients, total arch replacement in 75, distal arch replacement in 35, descending aorta replacement in 75, replacement of the thoracoabdominal aorta in 28, and extra-anatomical repair and others in 15. The technique of extracorporeal circulation was selective cerebral perfusion in 69 patients, deep hypothermic circulatory arrest in 90, femoro-femoral bypass in 39, left heart bypass in 12, and temporary aorto-arterial bypass in 30, and others in 21.

RESULT

Early mortality was 21% (54 patients), which was greater than that of the control group (113 patients, 13%, P < 0.01). The incidence of postoperative stroke, transient brain dysfunction, and respiratory problems was higher in the study group (P < 0.01 in all). Mean duration in ICU among survivors was 9.3 +/- 20.2 days and that of the control group was 5.9 +/- 2.8 days (P < 0.01). In a recent series (from 1991 to 1997) postoperative mortality improved to 15.6% (30/192 patients) in the study group however this result was still inferior to that of the control group (8.6%, 39/452, P = 0.03) however mortality of emergency surgery during the same periods was still high (31%, 11/35 patients). Logistic regression analysis revealed that significant risk factors for postoperative hospital death were surgery before 1991, age over 70 years, preoperative cardiac problems, aneurysm rupture, postoperative stroke, low output syndrome, bleeding, and acute renal failure. Postoperative follow-up was obtained in 408 patients/year and the longest period was 10.2 years. Late deaths were documented in 31 patients. Five-year and 10-year survival were 61.2 +/- 5.7% and 31.3 +/- 16.4%, respectively. In the control group the 5-year and 10-year survival were 78.0 +/- 2.1% and 62.5 +/- 4.0%, respectively (P = 0.03). However, survival of the early survivors in the study group was similar with that of the age-matched normal population. Aortic reoperation was performed in 13 patients. Freedom from aortic reoperation was 86.7 +/- 4.2% at 5 years and 80.5 +/- 7.1% at 10 years in the study group and 83.4 +/- 1.8% at 5 years and 64.1 +/- 13.3% at 10 years in the control group (P = 0.27).

CONCLUSION

Although recent advances have been achieved, early and long-term results of surgery for thoracic aortic aneurysm in patients older than 70 years were less satisfactory compared with those of patients under 70 years of age, especially in patients who required emergency surgery. Preoperative disorder of the vital organ systems was considered to be the main causative factor for high mortality, however, pertinent surgical strategies are necessary to improve the outcome of elderly patients.

Lung volume reduction surgery combined with cardiac interventions

OBJECTIVE

Postoperative course and functional outcome were evaluated in patients who underwent lung volume reduction surgery (LVRS) or in combination with valve replacement (VR), percutaneous transluminal coronary angioplasty (PTCA), placement of a stent, or coronary artery bypass grafting (CABG).

METHODS

Patients with severe bronchial obstruction and hyperinflation due to pulmonary emphysema were evaluated for lung volume reduction surgery. Cardiac disorders were screened by history and physical examination and assessed by coronary angiography. Nine patients were accepted for LVRS in combination with an intervention for coronary artery disease (CAD). In addition, three patients with valve disease and severe emphysema were accepted for valve replacement (two aortic-, one mitral valve) only in combination with LVRS. Functional results over the first 6 months were analysed.

RESULTS

Pulmonary function testing demonstrates a significant improvement in postoperative FEV1 in patients who underwent LVRS combined with an intervention for CAD. This was reflected in reduction of overinflation (residual volume/total lung capacity (RV/TLC)), and improvement in the 12-min walking distance and dyspnea. Median hospital stay was 15 days (10-33). One patient in the CAD group died due to pulmonary edema on day 2 postoperatively. One of the three patients who underwent valve replacement and LVRS died on day 14 postoperatively following intestinal infarction. Both survivors improved in pulmonary function, dyspnea score and exercise capacity. Complications in all 12 patients included pneumothorax (n = 2), hematothorax (n = 1) and urosepsis (n = 1).

CONCLUSION

Functional improvement after LVRS in patients with CAD is equal to patients without CAD. Mortality in patients who underwent LVRS after PTCA or CABG was comparable to patients without CAD. LVRS enables valve replacement in selected patients with severe emphysema otherwise inoperable.