Working capacity and cardiopulmonary function after extensive lung resections

Pulmonary hypertension after pneumonectomy for lung cancer

Background

We aimed to consolidate our clinical observations regarding the development of pulmonary hypertension following pneumonectomy for lung cancer.

Methods

Sixty-nine of 82 initially selected patients without pulmonary or cardiac comorbidities, who underwent pneumonectomy for lung cancer between October 2009 and October 2011, accomplished our protocol. Mean patient age was 60.6 years (range 44–78 years) and 10.1% were women.

Results

Postoperative complications occurred in 16 (23.2%) patients. Mortality at 1, 12, and 18 months postoperatively was 4.3%, 15.9%, and 29%, respectively. One year postoperatively, 37.9% of patients developed mild to moderate pulmonary hypertension and 3.4% had severe pulmonary hypertension. The calculated mean pulmonary artery systolic pressure at 1, 6, and 12 months postoperatively was 21.9 ± 6.6, 27.3 ± 9.3, and 34.1 ± 14 mm Hg, respectively ( p < 0.001). Receiver operating characteristic curve analysis showed a cutoff point at 35.5 mm Hg for late postoperative (at 12 months) pulmonary artery systolic pressure (sensitivity 80%, specificity 82%; p < 0.001) related to suboptimal clinical outcomes (decreased performance status or death), with a detected 18-fold risk for these patients ( p < 0.001).

Conclusions

Pulmonary hypertension may occur after pneumonectomy with its known adverse effects. Patients with late postoperative pulmonary artery systolic pressure > 35.5 mm Hg are at higher risk of a suboptimal clinical outcome.

Adjustments in cardiorespiratory function after pneumonectomy: results of the pneumonectomy project

OBJECTIVE

To assess lung function, gas exchange, exercise capacity, and right-sided heart hemodynamics, including pulmonary artery pressure, in patients long term after pneumonectomy.

METHODS

Among 523 consecutive patients who underwent pneumonectomy for lung cancer between January 1992 and September 2001, 117 were alive in 2006 and 100 were included in the study. During a 1-day period, each patient had complete medical history, chest radiographs, pulmonary function studies, resting arterial blood gas analysis, 6-minute walk test, and Doppler echocardiography.

RESULTS

Most patients (N = 73) had no or only minimal dyspnea. On the basis of predicted values, functional losses in forced expiratory volume in 1 second and forced vital capacity were 38% ± 18% and 31% ± 24%, respectively, and carbon monoxide diffusing capacity decreased by 31% ± 18%. There was a significant correlation between preoperative and postoperative forced expiratory volume in 1 second (P < .01), and more hyperinflation was associated with better lung function (P < .01 for forced expiratory volume in 1 second). Gas exchange was normal at rest (Pao(2) = 88 ± 10 mm Hg; Paco(2) = 42 ± 3 mm Hg), and exercise tolerance (6-minute walk) was also normal (83% ± 17% of predicted values). Thirty-two patients had some degree of pulmonary hypertension, but in most of those cases, it was mild to moderate (mean systolic pressure of 36 ± 9 mm Hg) and not associated with significant differences in lung function (P = .57 for forced expiratory volume in 1 second), gas exchange (P = .08), and exercise capacity (P = .66).

CONCLUSIONS

These findings indicate that despite worsening of lung function by approximately 30% after pneumonectomy, most patients can adjust to living with only 1 lung. Pulmonary hypertension is uncommon and in most cases only mild to moderate.

Cardiac Function and Position More Than 5 Years After Pneumonectomy

BACKGROUND

Pneumonectomy not only reduces the pulmonary vascular bed but also changes the position of the heart and large vessels, which may affect the function of the heart. We investigated long-term effects of pneumonectomy on right ventricular (RV) and left ventricular (LV) function and whether this function is influenced by the side of pneumonectomy or the migration of the heart to its new position.

METHODS

In 15 patients who underwent pneumonectomy and survived for more than 5 years, we evaluated by dynamic magnetic resonance imaging the function of the RV and LV and the position of the heart within the thorax.

RESULTS

Long-term effect of pneumonectomy on the position of the heart is characterized by a lateral shift after right-sided pneumonectomy and rotation of the heart after left-sided pneumonectomy. Postoperatively, heart rate was high (p = 0.006) and stroke volume was low (p = 0.001), compared with the reference values, indicating impaired cardiac function. Patients after right-sided pneumonectomy had an abnormal low RV end-diastolic volume of 99 +/- 29 mL together with a normal LV function. No signs of RV hypertrophy were found. In left-sided pneumonectomy patients, RV volumes were normal whereas LV ejection fraction was abnormally low.

CONCLUSIONS

The long-term effects of pneumonectomy on the position of the heart are characterized by a lateral shift in patients after right-sided pneumonectomy and rotation of the heart in patients after left-sided pneumonectomy. Overall, cardiac function in long-term survivors after pneumonectomy is compromised, and might be explained by the altered position of the heart.

Effect of Lung Resection on Exercise Capacity and on Carbon Monoxide Diffusing Capacity During Exercise

OBJECTIVE

To evaluate the effect of lung resection on lung function and exercise capacity values, including diffusion capacity of the lung for carbon monoxide (Dlco), during exercise, and to determine whether postoperative lung function, including exercise capacity and Dlco during exercise, could be predicted from preoperative lung function and the number of functional segments resected.

DESIGN

Prospective study.

SETTING

Clinical pulmonary function laboratory in a university teaching hospital.

PATIENTS

Twenty-eight patients undergoing lung resection at Vancouver General Hospital from October 1998 to May 1999, were studied preoperatively and 1-year postoperatively.

INTERVENTIONS

We determined FEV(1) and FVC, and maximal oxygen uptake (Vo(2)max) and maximal workload (Wmax) achieved during incremental exercise testing. We used the three-equation modification of the single-breath Dlco technique to determine Dlco at rest (RDlco) and during steady-state exercise at 70% of Wmax, and the increase in Dlco from rest to exercise (ie, the mean increase in Dlco percent predicted at 70% of Wmax from resting Dlco percent predicted [(70%-R)Dlco]). We calculated the predicted postoperative (PPO) values for all the above parameters using the preoperative test data and the extent of functioning bronchopulmonary segments resected, and compared the results with the actual 1-year postoperative results.

RESULTS

Following lung resection, there was a significant reduction in FEV(1), FVC, and Dlco with decreases of 12%, 13%, and 22% predicted, respectively. There were also significant decreases in Vo(2)max per kilogram of 2.1 mL/min/kg (8% of predicted Vo(2)max) and in Wmax of 12 W (7% of predicted Wmax). However, (70%-R)Dlco did not significantly decrease after lobectomy but decreased after pneumonectomy. The calculated PPO values significantly underestimated postoperative values after pneumonectomy but were acceptable for lobectomy.

CONCLUSIONS

Exercise tests may be better indicators of functional capacity after lung resection than measurements of FEV(1) and FVC or RDlco. PPO results calculated by estimating the functional contribution of the resected segments, are comparable with those obtained using ventilation-perfusion lung scanning and significantly underestimate postoperative lung function after pneumonectomy, but are acceptable for lobectomy.

Longterm effects of pulmonary resection on cardiopulmonary function

BACKGROUND

Major lung resection decreases ventilatory capacity and reduces exercise tolerance, impairing postoperative quality of life. But we have often seen respiratory symptoms improve during several years of postoperative followup. In the current study, we evaluated postoperative changes in cardiopulmonary function on exertion of patients with lung cancer surviving for more than three years, and the corresponding changes of their respiratory symptoms.

METHODS

The effects of pulmonary resection on cardiopulmonary function were evaluated in eight patients with lung cancer. Pulmonary function tests and hemodynamic study at rest and during exercise were performed before, in the early (4 to 6 months) and late (42 to 48 months) postoperative phases after major lung resection.

RESULTS

None of the eight patients had any remarkable symptoms before lung resection. In the early postoperative study, the general condition of five patients deteriorated compared with their preoperative status. In the late postoperative study, four patients showed an improvement of their daily activities from the early postoperative phase. Pulmonary function in the late postoperative phase did not show major changes except for airway resistance and percentage of carbon monoxide diffusing capacity as compared with the early phase, which showed deterioration as compared with the preoperative period. Cardiac index and stroke volume index were significantly decreased during exercise on maximal effort in the late postoperative phase compared with other phases. These results suggest that the peak blood flow per unit of remaining lung during exercise becomes lower with time after lung resection, indicating deterioration of the condition of the pulmonary vascular bed. The deterioration was also revealed from the pressure-flow curve.

CONCLUSIONS

The condition of the pulmonary vascular bed after major lung resection does not improve, even in the late postoperative phase, although clinical symptoms were sometimes improved compared with the early postoperative period.

Recovery and limitation of exercise capacity after lung resection for lung cancer

OBJECTIVE

To assess the effects of pulmonary resection for lung cancer on postoperative recovery and limitation of exercise capacity.

METHODS

Eighty-two patients (20 pneumonectomies, 62 lobectomies) underwent spirometric pulmonary tests and exercise capacity tests preoperatively, and at 3 months and more than 6 months after the operation.

RESULTS

In the lobectomy group, FEV1 vital capacity (VC), and maximum oxygen consumption (VO2max) decreased significantly 3 months after the operation and improved after more than 6 months, but did not reach the preoperative values. In the pneumonectomy group, FEV1 VC, and VO2max decreased 3 months after the surgery and the values did not recover thereafter. In comparison with preoperative values, the functional percentage losses after more than 6 months for lobectomies and pneumonectomies were 11.2% and 36.1% for FEV1, 11.6% and 40.1% for VC, and 13.3% and 28.1% for VO2max, respectively. Postoperatively, maximal minute ventilation (VEmax), the maximal heart rate percentage, and maximal O2 pulse during the exercise test significantly decreased in both the lobectomy and pneumonectomy groups. Nevertheless, VEmax and O2 pulse improved more than 6 months after lobectomy compared with the value at 3 months, but not after pneumonectomy. Breathing reserve did not differ before and after surgery in the lobectomy group, although it decreased significantly after surgery in the pneumonectomy group. Subjectively, postoperative exercise after lobectomy was limited by leg discomfort (64% at more than 6 months after surgery); after pneumonectomy, exercise was limited by dyspnea (60%).

CONCLUSIONS

These results suggest that there are differences between lobectomy and pneumonectomy for lung cancer in terms of recovery and limitation of exercise capacity.

RETRACTED: Cardiorespiratory changes in patients undergoing pulmonary resection using different anesthetic management techniques

OBJECTIVE

Pulmonary resection may be associated with considerable alterations of the cardiorespiratory system. The ideal anesthetic regimen for these patients is not yet definitely determined.

DESIGN

Prospective, randomized study.

SETTING

Single-institutional, clinical investigation in a thoracic anesthesia department of a university hospital.

PARTICIPANTS

Fifty consecutive patients scheduled for elective thoracic surgery for lung cancer.

INTERVENTIONS

In 20 patients undergoing lobectomy, fentanyl/propofol/nitrous oxide/vecuronium anesthesia was used, and extubation was planned immediately after surgery (group 1A, early extubation). Another 20 patients with lobectomy were anesthetized during fentanyl/midazolam/vecuronium, and they were extubated in the intensive care unit (ICU) (group 1B, late extubation). Ten patients underwent pneumonectomy (extubation planned in the ICU) (group 2, pneumonectomy). Patients of groups 1A and 1B were selected according to a randomized sequence.

MEASUREMENTS AND MAIN RESULTS

Extensive hemodynamic monitoring was performed using a pulmonary artery catheter by which right ventricular hemodynamics (right ventricular ejection fraction [RVEF], right ventricular end-systolic, and end-diastolic volumes) were additionally measured. Measurements were performed after induction of anesthesia (supine position, baseline values), before surgery (lateral position), 30 minutes after one-lung ventilation (OLV) was induced, at the end of surgery (supine position), 2 hours after surgery (in ICU), and on the morning of the first postoperative day. Pneumonectomy resulted in an increase in the pulmonary wedge pressure (from 12.2 +/- 2.9 to 18.3 +/- 3.8 mmHg) and a deterioration in right ventricular hemodynamics with a decrease in RVEF from 40.6 +/- 3.4% to 28.8 +/- 4.3% at the end of surgery. These changes were also seen on the morning of the first postoperative day. PaO2/FI02, Qs/Qt, VO2I, and DO2I were also significantly different between pneumonectomy and lobectomy patients. Intraoperatively, patients of group 1A and 1B showed almost similar cardiorespiratory data. During OLV, PaO2/FIO2 was significantly less reduced in group 1A (to 292 +/- 98 mmHg) than in group 1B (to 200 +/- 120 mmHg). Postoperatively, patients of group 1A were orientated, and physiotherapy could be started early. No relevant differences with regard to cardiorespiratory parameters were observed between group 1A and group 1B in the postoperative period until the first postoperative day.

CONCLUSIONS

In comparison with lobectomy patients, pneumonectomy resulted in more pronounced and sustained deterioration in right ventricular hemodynamics. The kind of anesthesia regimen did not influence most of the cardiorespiratory parameters intraoperatively, except for Qs/Qt, which was least compromised in the propofol patients during OLV. Early extubation could safely be performed in the lobectomy patients anesthetized with propofol without showing any negative cardiorespiratory effects.

Right-to-left interatrial shunt causing platypnea after pneumonectomy. A recent experience and diagnostic value of dynamic magnetic resonance imaging

Shortness of breath after pneumonectomy is a common finding that has multiple causes. We report the cases of two patients with shortness of breath on assuming an upright posture (platypnea) that followed pneumonectomy; these individuals developed right-to-left shunt across a patent foramen ovale (PFO) with normal right-sided intracardiac pressures. Both contrast echocardiography and magnetic resonance imaging (MRI), including a recently introduced dynamic ultrafast imaging technique, proved helpful in diagnosing this condition noninvasively.

Cardiopulmonary function after pulmonary lobectomy in patients with lung cancer

The effects of pulmonary lobectomy on cardiopulmonary function were investigated in 9 patients with lung cancer. Hemodynamic studies at rest and during exercise were performed before and 4 to 6 months after the operation. Differences in hemodynamics between before and after operation were observed with respect to heart rate, pulmonary arterial pressure, pulmonary vascular resistance index, and stroke volume index. Heart rate, pulmonary arterial pressure, and pulmonary vascular resistance index were significantly increased after operation, whereas stroke volume index was significantly decreased. It is thought that cardiac index was preserved by the increase in heart rate despite a decrease in stroke volume index associated with the decreased pulmonary vascular bed after the operation. When driving pressure and cardiac index were studied after operation, the pressure at rest and during exercise was higher, and the pressure-flow curve increased more steeply, as compared with the preoperative values. These results suggest a significant deterioration in cardiopulmonary function after lobectomy. As the patient characteristics were heterogeneous (five lobectomies and four bilobectomies), and their findings are limited, additional studies may be necessary in the future.

Respiratory muscle limitation in patients after pneumonectomy

Exercise capacity is significantly impaired in postpneumonectomy patients who have relatively normal remaining lungs. Our objectives are to determine (1) the nature and extent of mechanical ventilatory abnormalities and oxygen cost of breathing in such patients, and (2) the efficacy of a selective respiratory muscle training program in improving ventilatory and exercise performance. A group of eight postpneumonectomy and eight normal subjects (mean ages 59 and 50 yr, respectively) were studied during steady-state exercise and resting voluntary hyperventilation. Ventilation, work of breathing, cardiac output, and oxygen costs of breathing were determined. Four postpneumonectomy and five normal subjects were studied before and after a respiratory muscle training program. In patients after pneumonectomy compared with normal control subjects, maximal oxygen uptake (VO2) was 56% lower (p < 0.001). Work of breathing was significantly higher at a given ventilation. Mechanical efficiency of ventilation was lower by 44% (p < 0.05). Near maximal VO2, 48% of any additional increment of total-body VO2 was required to sustain the associated increment in ventilatory work, compared with 28% in normal subjects (p < 0.05), suggesting that competition between respiratory and nonrespiratory muscles for oxygen delivery is a significant factor limiting exercise after pneumonectomy. After respiratory muscle training, maximal respiratory pressures improved but maximal sustained ventilation and maximal VO2 did not improve significantly, suggesting that selective respiratory muscle training is of limited utility in postpneumonectomy patients.

Cardiopulmonary function after lobectomy or pneumonectomy for pulmonary neoplasm

Resection of pulmonary tissue for bronchial carcinoma causes a decrease in vital capacity of 15% after lobectomy and 35-40% following pneumonectomy. After operation the lung becomes stiffer and elastic recoil pressure and transdiaphragmatic pressure at TLC increase. Maximum effort tolerance decreases after pneumonectomy with a normal pulmonary artery pressure at rest and an increase in pulmonary artery pressure and in pulmonary vascular resistance on effort, compared to preoperative values. Cardiac output and stroke volume during effort show a decrease after operation with an increase in peripheral arterial blood pressure and in peripheral vascular resistance. Arterial oxygen saturation on effort decreases after pneumonectomy, possibly due to the absolute decrease in diffusing capacity. When comparing resting and exercise values at identical work loads, increases in systemic arterial blood pressure, pulmonary and systemic vascular resistance and arteriovenous oxygen difference were similar although generally less pronounced after lobectomy compared to pneumonectomy; cardiac output, stroke volume and oxygen consumption showed the same tendency to decrease after lobectomy and pneumonectomy.

Post-pneumonectomy syndrome. Surgical correction using Silastic implants

A post-right pneumonectomy syndrome is described which manifests symptoms of exertional dyspnea and inspiratory stridor on rapid inspiration. These symptoms were associated with marked rightward and posterior deviation of the trachea, over-distention of the left lung with its herniation into the right side of the chest and kinking of the left lower lobe bronchus. At the time of surgery, the tracheal deviation, lung herniation and the kink in the left lower lobe bronchus were immediately corrected by releasing the adhesions between the malpositioned structures and the right chest wall. To maintain the corrected positions, Silastic implants totalling a volume of 990 ml were placed into the space created in the right chest. Following surgery, exertional dyspnea was present with only extraordinary activity, and inspiratory stridor was eliminated. The patient remains asymptomatic three years following surgical correction, and is able to carry on a normal and productive life. We conclude that a syndrome associated with marked exertional dyspnea and inspiratory stridor might develop in situations of marked tracheal shift and overdistention of the remaining lung following right pneumonectomy.