Effect of cardiopulmonary bypass on early graft dysfunction in clinical lung transplantation

Use of cardiopulmonary bypass for lung transplantation: a 10-year experience

OBJECTIVE

The use of cardiopulmonary bypass (CPB) for lung transplantation (LTx) has been reported previously. This study reports the authors' experience of planned and unplanned use of cardiopulmonary bypass for LTx.

DESIGN

Case series.

SETTING

A university teaching hospital.

PARTICIPANTS

Patients undergoing LTx.

INTERVENTIONS

A retrospective analysis of the charts of all patients having undergone LTx over the last 10 years.

MEASUREMENTS AND MAIN RESULTS

Among 140 LTx, 23 (16%) were performed with the use of CPB. CPB was planned in 11 cases and unplanned in the 12 other cases. The use of CPB is associated with a longer period of postoperative mechanical ventilation, more pulmonary edema, more blood transfusion requirement, and an increase in postoperative mortality at 48 hours and 1 month. Surgical difficulties related to the dissection of the native left lung and acute right ventricular failure are the main reasons for unscheduled use of CPB.

CONCLUSION

Scheduled and unscheduled CPB for LTx are associated with an increased mortality at 1 month and 1 year.

High Donor Age, Low Donor Oxygenation, and High Recipient Inotrope Requirements Predict Early Graft Dysfunction in Lung Transplant Recipients

BACKGROUND

Early dysfunction in lung transplants is characterized by poor oxygenation, which may then lead to prolonged mechanical ventilation. This may be due to a combination of donor, recipient, and management factors. Our aim was to determine the incidence and severity of hypoxia and graft dysfunction and which factors were directly associated with poor oxygenation within the first 24 hours after lung transplantation.

METHODS

A retrospective study of all 128 lung transplants between 1999 and 2002 was undertaken. Multiple linear regression analysis was performed to determine which donor, recipient, operative, and intensive care unit (ICU) parameters were associated with the worst recorded arterial blood gas partial pressure of oxygen (PAO2)/fraction of inspired oxygen (FIO2) ratio in the initial 24 hours after operation.

RESULTS

Eighty-three percent of the patients (104 of 128) had a PAO2/FIO2 ratio below 300 within the first 24 hours post-transplantation, and 60% (77 of 128) had a PAO2/FIO2 ratio below 200. A high donor age (p = 0.004), low donor PAO2 (p = 0.007), and high post-operative inotrope requirements (p = 0.02) were correlated with a low PAO2/FIO2 ratio. Recipient diagnosis, ischemic time, use of cardiopulmonary bypass, fluid balance in the ICU, and cardiac index were not related. There was no difference in the long-term outcomes of patients with high or low PAO2/FIO2 ratios.

CONCLUSIONS

A low PAO2/FIO2 ratio is a common finding in the first 24 hours after lung transplantation. Donor factors such as age and PAO2, and the need for increasing inotrope requirements in ICU predict early graft dysfunction and hypoxia.

Outcome of lung transplantation for patients requiring concomitant cardiac surgery

BACKGROUND

The clinical results of lung transplantation and concomitant cardiac surgery are unclear. The effect of cardiopulmonary bypass on the pulmonary allograft is controversial, and the effect of cardiac arrest and cardiac surgery in this setting is unknown. Our aim was to review the operative results and long-term survival in this group of patients.

METHODS

A retrospective review of all lung transplantations between 1988 and 2003 was performed. Patients who had concomitant cardiac surgery during lung transplantation were compared with those who underwent lung transplantation alone. The variables analyzed included allograft ischemic times, use of cardiopulmonary bypass, early graft dysfunction, postoperative morbidity, survival, length of mechanical ventilation, length of stay in the intensive care unit, and overall hospital stay.

RESULTS

During this period, 35 of 700 lung transplant recipients (15 single and 20 bilateral transplantations) underwent concomitant cardiac surgery. The cardiac procedures were for patent foramen ovale (n = 18), atrial septal defect (n = 9), ventricular septal defect (n = 2), coronary bypass (n = 4), and "other" (n = 2). Allograft ischemic time, use of extracorporeal membrane oxygenation, length of hospital stay, operative mortality, and survival were not significantly different between the 2 groups. Ventilator time and intensive care unit stay were longer in the cardiac surgery group.

CONCLUSIONS

Cardiac surgery at the time of lung transplantation can be performed with acceptable morbidity and mortality. The immediate and long-term survival in these patients is similar to that of other lung transplant recipients. Lung transplantation should continue to be offered to patients with normal ventricular function who require concomitant limited cardiac surgery.

Long-Term Results of Lung Transplantation for Emphysema

INTRODUCTION

We sought to assess the differences between lung transplantation (LT) to treat emphysema, versus other pulmonary diseases.

METHODS

This retrospective review of lung transplantations (LTs) performed from October 1993 to September 2003, included donor and recipient demographic data, pulmonary function, oxygenation, postoperative complications, incidence of rejection and pneumonia, and survival.

RESULTS

Of 159 LTs performed the 39 transplanted to treat emphysema (24.4%), were in 33 men and 6 women of age 50.9 +/- 8.7 years (men, 25 to 65 years). There were differences between the emphysema vs other groups in terms of age (P < .001), gender (P = .001), need for bypass (P = .004), and immediate posttransplantation oxygenation index (P = .001). Perioperative mortality tended to be lower among patients with emphysema (2.7% vs 10.8%; P = .131). The incidences of complications and acute rejections was similar. Forced vital capacity, forced expiratory volume in 1 second, arterial oxygen tension, and arterial carbon dioxide tension improved significantly post-Tx. Actuarial survivals were 82%, 68%, and 63%, respectively, at 1, 3, and 7 years posttransplantation for emphysema patients vs 60%, 53%, and 42%, respectively, at 1, 3, and 7 years posttransplantation for non-emphysema patients (P = .049).

CONCLUSION

Lung transplantation in patients with emphysema offers good long-term survival, with significant improvement in functional status and low morbidity. The older age of emphysema patients was not associated with a higher incidence of postoperative complications.

Anesthetic Considerations for Lung Volume Reduction Surgery and Lung Transplantation

Anesthetic considerations for lung transplantation and LVRS have been reviewed, with an emphasis on critical intraoperative junctures and decision points. Cognizance of these issues promotes coordinated and optimal care and provides the potential to improve outcome in this particularly high-risk population.

Lung transplantation for emphysema

Great strides have been made in lung transplantation in the past two decades. Changes in technique, immunosuppression regimens, and treatment of infectious complications have led to improvements in survival and functional results. Current areas of discussion concern the use of single lung transplantation versus bilateral sequential lung transplantation and the criteria for allocating donor lungs. This article reviews the current state of lung transplantation for emphysema and provides insight from more than one decade of experience with Washington University's lung transplant program.

Risk quantification of early outcome after lung transplantation: donor, recipient, operative, and post-transplant parameters

BACKGROUND

Because there is no reliable evaluation system of recipient acuity after lung transplantation, comparing patients among centers is difficult. The purpose of our study was to identify risk factors for 30-day mortality and prolonged intensive care unit stay and to develop a scoring system to evaluate the severity of impairment and to predict surgical outcomes.

METHODS

We prospectively collected data from 122 lung transplant recipients and from 119 donors from January 1997 to June 2000. We assessed donor, recipient, and operative factors; ischemic time; and immediate post-operative physiologic parameters to identify risk factors for 30-day mortality and prolonged intensive care unit stay. Furthermore, we sub-classified these factors into grades to develop a scoring system for predicting surgical outcomes.

RESULTS

Cardiopulmonary bypass use, body mass index >25 kg/m2, immediate post-operative systolic pulmonary arterial pressure, trend of oxygenation index from 12 to 24 hours after transplantation, and the Acute Physiology and Chronic Health Evaluation II score correlated significantly with outcomes, and the sum of these 5 scores correlated strongly with outcomes (p < 0.0001).

CONCLUSIONS

We conclude that the total score of these 5 risk factors could be used to predict 30-day mortality and prolonged intensive care unit stay. This scoring system also will facilitate standardization among transplant centers in evaluating post-transplant severity of illness.

[Prognostic factors of early morbidity and mortality after lung transplantation]

OBJECTIVES

Despite years of experience with lung transplantation, the rate of perioperative mortality remains high. The objective of this study was to look at our experience in the early postoperative period following lung transplantation in an effort to identify possible pre-, intra- and postoperative risk factors associated with mortality.

PATIENTS AND METHODS

A retrospective study of 68 consecutive patients receiving lung transplants over a period of 56 months. The conditions that led to transplantation were obstructive disease (40%), interstitial disease (33%) and suppurative disease (27%). Pre-, intra- and postoperative characteristics of donors and recipients were analyzed for their relation to morbidity and mortality. Statistical studies were done using SPSS 10.0 software. A p-value less than.05 was considered significant. Univariate analysis identified variables associated with the incidence of mortality in the postoperative recovery unit, and the variables with statistically significant associations were entered into multivariate analysis, using a logistic regression model to calculate odds ratio (OR) and 95% confidence intervals (CI).

RESULTS

No donor variables correlated with mortality. Patients with suppurative lung disease had a lower mortality rate (0% vs 30%; P = 0.04). Mortality was related to ischemic time longer than 300 minutes (OR = 2) and the use of extracorporeal circulation (OR = 4). A PaO2/FiO2 ratio less than 150 during the first 24 hours following transplantation (OR = 5) and reoperation due to bleeding (OR = 12) were the variables showing the highest correlations with mortality during the early postoperative period.

CONCLUSIONS

The mortality rate during the early postoperative period in our series was 22%. The survival rate was better in patients with suppurative lung disease. Bleeding that required reoperation and early graft dysfunction (defined in part by a PaO2/FiO2 ratio less than 150 during the first 24 hours) were the variables that best predicted death in the early postoperative period following lung transplantation.

Respiratory failure after lung transplantation

STUDY OBJECTIVES

To characterize patients who acquired postoperative respiratory failure after lung transplantation (LT), and to identify risks associated with postoperative respiratory failure and poor surgical outcome.

STUDY DESIGN

Retrospective clinical analysis in a tertiary care transplantation center.

METHODS

We reviewed the records of 80 consecutive patients who underwent LT from April 1994 to May 1999, analyzing their records for a number of preoperative and perioperative variables and complications.

RESULTS

Forty-four patients (55%) acquired postoperative respiratory failure and had a mortality rate of 45%. No difference was noted between patients with respiratory failure and those without in terms of age (mean +/- SD, 56 +/- 9 years vs 53 +/- 11 years), gender, baseline pretransplant arterial blood gas analysis (PaCO(2), 46 +/- 9 mm Hg vs 44 +/- 10 mm Hg), and cardiopulmonary exercise testing (maximum oxygen uptake, 0.76 +/- 0.44 L/min/m(2) vs 0.82 +/- 0.20 L/min/m(2)). Ischemic reperfusion lung injury (IRLI) [55%] and perioperative cardiovascular/hemorrhagic events (36%) were the major contributors to the development of respiratory failure. Preoperative pulmonary hypertension, right ventricular (RV) dysfunction, ischemic times, and need for bilateral LT and cardiopulmonary bypass (CPB) were higher in patients with respiratory failure (p < 0.05) compared to recipients without respiratory failure. However, the presence of preoperative moderate-to-severe RV dysfunction was the only independent factor (odds ratio, 21.9; 95% confidence interval, 1.6 to 309.0).

CONCLUSION

Respiratory failure after LT is common and is associated with high morbidity and mortality. Respiratory failure often occurred in patients with operative technical complications, cardiovascular events, and postoperative IRLI, which were observed most in patients requiring CPB because of RV dysfunction.

Thirteen-year experience in lung transplantation for emphysema

BACKGROUND

Emphysema is the most common indication for lung transplantation. Recipients include younger patients with genetically determined alpha-1 antitrypsin deficiency (AAD) and, more commonly, patients with chronic obstructive pulmonary disease (COPD). We analyzed the results of our single-institution series of lung transplants for emphysema to identify outcome differences and factors predicting mortality and morbidity in these two groups.

METHODS

A retrospective analysis was undertaken of the 306 consecutive lung transplants for emphysema performed at our institution between 1988 and 2000 (220 COPD, 86 AAD). Follow-up was complete and averaged 3.7 years.

RESULTS

The mean age of AAD recipients (49 +/- 6 years) was less than those with COPD (55 +/- 6 years; p < 0.001). Hospital mortality was 6.2%, with no difference between COPD and AAD, or between single-lung transplants and bilateral-lung transplants. Hospital mortality during the most recent 6 years was significantly lower (3.9% vs 9.5%, p = 0.044). Five-year survival was 58.6% +/- 3.5%, with no difference between COPD (56.8% +/- 4.4%) and AAD (60.5% +/- 5.8%). Five-year survival was better with bilateral-lung transplants (66.7% +/- 4.0%) than with single-lung transplants (44.9% +/- 6.0%, p < 0.005). Independent predictors of mortality by Cox analysis were single lung transplantation (relative hazard = 1.98, p < 0.001), and need for cardiopulmonary bypass during the transplant (relative hazard = 1.84, p = 0.038).

CONCLUSIONS

AAD recipients, despite a younger age, do not achieve significantly superior survival results than those with COPD. Bilateral lung transplantation for emphysema results in better long-term survival. Accumulated experience and modifications in perioperative care over our 13-year series may explain recently improved early and long-term survival.

Cardiopulmonary bypass for bilateral sequential lung transplantation in patients with chronic obstructive pulmonary disease without adverse effect on lung function or clinical outcome

OBJECTIVE

The use of cardiopulmonary bypass in lung transplantation remains controversial. Previous studies have concluded that cardiopulmonary bypass is deleterious, but these studies were confounded by the inclusion of patients with different diagnoses undergoing single- and double-lung transplantation with elective or emergency use of bypass. The goal of this study was to determine whether cardiopulmonary bypass has deleterious effects on lung function or clinical outcome by analyzing the cases of patients with a single disease entity and elective use of bypass for bilateral sequential lung transplantation.

METHODS

A retrospective review of 50 patients with chronic obstructive pulmonary disease who underwent bilateral sequential lung transplantation was performed. Fourteen patients who underwent elective cardiopulmonary bypass for 218.3 +/- 75.4 minutes were compared to 36 control patients.

RESULTS

After the operation, the bypass and nonbypass groups were not significantly different with respect to median duration of mechanical ventilation (1 day vs 1 day, P =.76), median stay in the intensive care unit (4 days vs 4 days, P =.44), median hospital stay (15.5 days vs 16 days, P =.74), mean increase in serum creatinine level (1.4 +/- 1.9 mg/dL vs 0.9 +/- 1.0 mg/dL, P =.33), and mean ratio of Pao(2) to fraction of inspired oxygen at 1 hour (376.6 +/- 123 vs 357.0 +/- 218, P =.75), at 24 hours (309.9 +/- 92 vs 350.6 +/- 122, P =.26), and at 48 hours (335.0 +/- 144 vs 316.2 +/- 120, P =.64). Late outcome markers compared between the bypass and nonbypass groups were the following: 1-year percentage predicted forced expiratory volume in 1 second (76.1% +/- 17.0% vs 85.3% +/- 21.7%, P =.24), 30-day mortality (7.1% vs 8.3%, P >.999), 1-year survival (85.7% vs 80.1%, P =.66), 3-year survival (64.3% vs 58.3%, P =.70), and the prevalence of bronchiolitis obliterans syndrome (0% vs 36.1%, P =.01).

CONCLUSION

Cardiopulmonary bypass appears to have no deleterious effect on early lung function or clinical outcome. We hope that this pilot study removes some of the unwarranted fear of the use of bypass in lung transplantation for chronic obstructive pulmonary disease.

Survival benefit of cardiopulmonary bypass support in bilateral lung transplantation for emphysema patients

BACKGROUND

This study is designed to examine a possible association of cardiopulmonary bypass (CPB) support and outcome of lung transplantation in a well-balanced group of emphysema patients.

METHODS

We performed a retrospective analysis of 62 consecutive primary bilateral lung transplantations for emphysema. Risk factors for their possible association with patient survival were analyzed by multivariate logistic regression.

RESULTS

The use of CPB support was associated with improved survival (odds ratio=0.25; P=0.038). The actuarial survival at 1 year was 97% for patients treated with CPB and 77% for patients treated without CPB support. In 28 patients (45%), 2 human leukocyte antigen (HLA)-DR mismatches between donor and recipient occurred, whereas 34 patients had 0 or 1 HLA-DR mismatches. The use of CPB support in the group with two HLA-DR mismatches was associated with improved survival (odds ratio=0.06; P=0.020). This association was not present in the group with 0 or 1 HLA-DR mismatches.

CONCLUSIONS

These results demonstrate a significant survival benefit of CPB support during bilateral lung transplantation in emphysema patients. The difference in survival benefit of CPB support between the patients with 0 or 1 HLA-DR mismatches and the patients with 2 HLA-DR mismatches indicates that the immunosuppressive effect of CPB support might be responsible for this survival benefit. The underlying immunological mechanism might be important in the future treatment of organ transplantation.

Imaging of the chest after lung transplantation

Lung transplantation is a well-accepted treatment for numerous lung diseases when medical or surgical therapy is ineffective or unavailable and the patient has a limited life expectancy (usually less than 2 to 3 years). When appropriate, single-lung transplantation is the preferred procedure because of a critical shortage of available donor lungs. Preoperative imaging is useful for selecting which lung should be transplanted, size matching between donor lung and recipient thorax, and screening for malignancy. Cardiac-related deaths, infection, and primary graft failure are the leading causes of perioperative death. Obliterative bronchiolitis is the "Achilles heel" of lung transplantation and accounts for the largest number of late deaths. This article reviews the preoperative, perioperative, and postoperative considerations and the utility of radiologic imaging after lung transplantation.

[Single-lung transplant and primary graft failure]

OBJECTIVE

To quantify primary graft failure (PGF) and its impact on perioperative and early mortality in single-lung transplant (SLT).

METHOD

We analyzed 35 SLT procedures performed using similar techniques. PGF was defined as a PaO2/FiO2 coefficient lower than 200 mmHg during the first 72 hours or ventilation assistance lasting longer than 5 days attributable to primary lung dysfunction. We defined perioperative mortality as occurring within 30 days of surgery and early mortality within 90 days.

RESULTS

Twenty-five men and 10 women received lungs, 22 for pulmonary fibrosis and 13 for emphysema; the mean age was 53.26 10.77 years. Twenty right SLTs were performed and 15 left SLTs. Twenty-nine donors were men and 6 were women, with a mean age of 29.31 12.33 years. Twenty-six died from cranial trauma, 8 from stroke and 1 from a brain tumor. The mean time of intubation was 1.69 1.35 days. The mean PaO2 was 470.71 70.82 mmHg. The mean time of ischemia was 201.77 62.64 minutes. Four patients (11.42%) developed PGF and 3 died during the perioperative period. Two additional patients died within the early postoperative period. Survival was 91.4% at one month and 85.5% at three months. The cause of donor death was the only variable that influenced the development of PGF.

CONCLUSION

We observed a low incidence of PGF and of perioperative and early mortality, with one and three month survival rates similar to those reported internationally.

Lung transplantation for primary pulmonary hypertension

Recent progress in medical therapies has diminished the role of transplantation in the management of PPH during the past decade. Drug therapy is not effective in some patients, responses to therapy are not sustained over time in others, and drug side effects eventually limit the benefits of treatment in a few more. Lung transplantation therefore ultimately is the only alternative for patients whose PPH is severe and cannot be managed medically. Choosing the right patient as a transplant candidate and the right time to make the initial referral to a transplant center are the crucial initial steps in the transplantation process, and the long waiting time before transplantation must be integrated into this decision. The outcome of lung and heart-lung transplantation for PHH has been good but sobering. Functional recovery has been excellent, but long-term survival results have been limited by the high prevalence of chronic allograft rejection.

Replacing cardiopulmonary bypass with extracorporeal membrane oxygenation in lung transplantation operations

Cardiopulmonary bypass (CPB) is required in some lung transplantation (LTx) operations. However, it increases risks of bleeding and early graft dysfunction. We report our experiences of replacing CPB with heparin-bound extracorporeal membrane oxygenation (ECMO) in LTx operations. If extracorporeal circulation was anticipated for the LTx operations, ECMO support was set up through the femoral venoarterial route after induction of anesthesia; then, LTx was done as usual. Five thousand units of heparin was injected intravenously during the femoral vessels cannulation, but no more was used during the first 24 h of ECMO support. If necessary, as in patients undergoing single LTx for end-stage pulmonary hypertension, the ECMO support was directly extended into the postoperative period until reperfusion edema of the graft lung subsided. Twelve single LTxs and 3 bilateral sequential single LTxs were done under ECMO support. The advantages of using femoral ECMO rather than conventional CPB in LTx operations were the operative field was not disturbed by the bypass cannula, stable cardiopulmonary function and normothermia were maintained throughout the operations, there were less blood loss and transfusion requirements, and the left LTx was as easily performed as the right LTx. Red blood cell transfusion requirements during the operation and the first postoperative day were 4.4 +/- 2.8 and 2.4 +/- 2.0 U, respectively, in 10 adult patients undergoing uncomplicated single LTx with ECMO support, and 4.3 +/- 1.3 and 1.5 +/- 1.5 U in 8 adult patients undergoing single LTx without any extracorporeal circulatory support. The difference was not significant between the 2 groups (p = 0.53 and 0.32 by Mann-Whitney U test). The ECMO did not increase blood transfusion requirements. In comparison, 13 U of red blood cell transfusion was required in 2 patients receiving single LTx under CPB support. The ECMO support made the postoperative critical care easier in recipients with graft lung edema. Except for 2 cases of primary graft failure, the ECMO could be weaned off and removed at bedside within a short period (27.9 +/- 24.6 h, n = 13) with no major complications. In conclusion, the heparin-bound femoral ECMO rather than CPB should be used for LTx operations unless concomitant cardiac repair is planned.

Lung deflation impairs alveolar epithelial fluid transport in ischemic rabbit and rat lungs

BACKGROUND

Because the fluid transport capacity of the alveolar epithelium after lung ischemia with and without lung deflation has not been well studied, we carried out experimental studies to determine the effect of lung deflation on alveolar fluid clearance.

METHODS

After 1 or 2 hr of ischemia, we measured alveolar fluid clearance using 125I-albumin and Evans blue-labeled albumin concentrations in in vivo rabbit lungs in the presence of pulmonary blood flow and in ex vivo rat lungs in the absence of any pulmonary perfusion, respectively.

RESULTS

The principal results were: (1) lung deflation decreased alveolar fluid clearance while inflation of the lungs during ischemia preserved alveolar fluid clearance in both in vivo and ex vivo studies; (2) alveolar fluid clearance was normal in the rat lungs inflated with nitrogen (thus, alveolar gas composition did not affect alveolar fluid clearance); (3) amiloride-dependent alveolar fluid clearance was preserved when the lungs were inflated during ischemia; (4) terbutaline-simulated alveolar fluid clearance was preserved in the hypoxic rat lungs inflated with nitrogen; (5) lecithinized superoxide dismutase, a scavenger of superoxide anion, and N(omega)-nitro-L-arginine methyl ester, an inhibitor of nitric oxide, preserved normal alveolar fluid clearance in the deflated rat lungs.

CONCLUSION

Lung deflation decreases alveolar fluid clearance by superoxide anion- and nitric oxide-dependent mechanisms.

Secondary pulmonary hypertension does not adversely affect outcome after single lung transplantation

OBJECTIVE

Primary and secondary pulmonary hypertension have been associated with poor outcomes after single lung transplantation. Some groups advocate double lung transplantation and the routine use of cardiopulmonary bypass during transplantation in this population. However, the optimal procedure for these patients remains controversial. The goal of our study was to determine the safety of single lung transplantation without cardiopulmonary bypass in patients with secondary pulmonary hypertension.

METHODS

We retrospectively reviewed 76 consecutive patients with pulmonary parenchymal disease who underwent single lung transplantation from 1992 to 1998. Recipients were stratified according to preoperative mean pulmonary artery pressure. Secondary pulmonary hypertension was defined as parenchymal lung disease with a preoperative mean pulmonary artery pressure of 30 mm Hg or more. Patients with primary pulmonary hypertension or Eisenmenger's syndrome were excluded from analysis.

RESULTS

Eighteen of 76 patients had secondary pulmonary hypertension. No patient with secondary pulmonary hypertension required cardiopulmonary bypass, whereas 1 patient without pulmonary hypertension required bypass. After the operation, no significant differences were seen in lung injury as measured by chest radiograph score and PaO(2)/FIO(2) ratio, the requirement for inhaled nitric oxide, the length of mechanical ventilation, the intensive care unit or hospital length of stay, and 30-day survival. There were no differences in the forced expiratory volume in 1 second or 6-minute walk at 1 year, or the incidence of rejection, infection, or bronchiolitis obliterans syndrome greater than grade 2. Survival at 1, 2, and 4 years after transplantation was 86%, 79%, and 65%, respectively, in the low pulmonary artery pressure group and 81%, 81%, and 61%, respectively, in the group with secondary pulmonary hypertension (P >.2).

CONCLUSION

We found that patients with pulmonary parenchymal disease and concomitant secondary pulmonary hypertension had successful outcomes as measured by early and late allograft function and appear to have acceptable long-term survival after single lung transplantation. Our results do not support the routine use of cardiopulmonary bypass or double lung transplantation for patients with this disorder.

Bilateral sequential single lung transplantation for pulmonary hypertension and Eisenmenger's syndrome

BACKGROUND

Lung transplantation, with and without intracardiac repair for pulmonary hypertension (PH) and Eisenmenger's syndrome (EIS), has become an alternative transplant strategy to combined heart and lung transplantation (HLT).

METHODS

Thirty-five patients with PH or EIS underwent either bilateral sequential single lung transplantation (BSSLT, group I, n = 13) or HLT (group II, n = 22). Another 74 patients, who underwent BSSLT for other indications, served as controls (group III). Immediate allograft function, early and medium-term outcomes, lung function, and 2-year survival were compared between the groups.

RESULTS

Comparisons between groups I and II showed no significant difference in any variables except percent predicted forced vital capacity. Immediate allograft function was significantly inferior (p < 0.05) and the blood loss was greater (p < 0.01) in group I when compared with those in group III. However, this resulted in no significant difference in early and medium-term outcomes, and 2-year survival between the 2 groups.

CONCLUSIONS

BSSLT for PH and EIS can be performed as an alternative procedure to HLT without an increase in early and medium-term morbidity and mortality. Results are comparable with BSSLT performed for other indications.

Acute pulmonary edema after lung transplantation: the pulmonary reimplantation response

BACKGROUND

Although the development of noncardiogenic pulmonary edema or pulmonary reimplantation response (PRR) after lung transplantation has been well described, the incidence has not been established and the relationship of PRR to clinical risk factors has not been analyzed.

STUDY OBJECTIVES

(1) To describe the incidence of PRR in lung transplant recipients, (2) to identify the predictors of PRR, (3) to examine the correlation of suspected predictors with the severity of PRR, and (4) to evaluate the impact of PRR on morbidity and mortality of lung transplant recipients.

DESIGN

Retrospective review of clinical records and radiographic studies.

SETTING

Tertiary care referral center.

PATIENTS

Ninety-nine consecutive patients with end-stage lung disease undergoing lung transplantation between February 1990 and October 1995.

METHODS

Review of clinical records and postoperative chest radiographs of all lung transplant recipients to identify patients who experienced PRR. Chest radiographs of patients with PRR were graded for severity on a scale of 0 (none) to 5 (very severe). Demographic, pre- and perioperative factors were also evaluated along with short- and long-term survival of patients with PRR.

RESULTS

Fifty-six of 99 lung transplant recipients (57%) experienced PRR. The median ischemia time of patients with and without PRR was 168 and 180 min, respectively (p = 0.62). The incidence of PRR was 51% in patients without preoperative pulmonary hypertension, 78% in mild to moderate pulmonary hypertension, and 58% in patients with severe pulmonary hypertension (p = 0.10). Incidence and severity of PRR was similar in patients receiving right, left, or double-lung transplantation. Similarly, age and sex of the recipients and underlying lung disease did not affect the incidence or severity of PRR. The incidence and severity of PRR was higher in patients undergoing cardiopulmonary bypass during lung transplantation. Patients with PRR had prolonged duration of mechanical ventilation and ICU stay. Overall, PRR did not affect the survival of the patients. However, survival of female lung transplant recipients was significantly better than male recipients (median survival, 60 vs 21 months; p = 0.02).

CONCLUSIONS

Acute pulmonary edema or PRR occurs frequently (57%) after lung transplantation. In this series, PRR was not associated with a prolonged ischemia time, preoperative pulmonary hypertension, the type of lung transplant, underlying lung disease, or age or sex of recipients. However, use of cardiopulmonary bypass during surgery was associated with increased incidence and severity of PRR. Also, the development of PRR resulted in prolonged mechanical ventilation and a longer ICU stay, but did not affect survival. Female lung transplant recipients survived significantly longer than male recipients. The reason for this difference in survival is unclear.

The use of continuous positive airway pressure by face mask and thoracic epidural analgesia after lung transplantation. Gothenburg Lung Transplant Group

OBJECTIVE

To evaluate the clinical use of continuous positive airway pressure (CPAP) and thoracic epidural analgesia (TEA) after lung transplantation (LTx).

DESIGN

Retrospective case series.

SETTING

Cardiothoracic intensive care unit (ICU) at a university hospital.

PARTICIPANTS

All heart-lung, bilateral, and single-lung transplant recipients between 1990 and 1996 at this institution (n = 102).

INTERVENTIONS

Postoperative pain was controlled by a thoracic epidural infusion of bupivacaine, 1 mg/mL, and sufentanil, 1 microg/mL. After extubation, CPAP, 5 to 10 cm H2O by face mask, was used to prevent reperfusion edema.

MEASUREMENTS AND MAIN RESULTS

In 99 patients, the length of ventilation (LOV) was a median of 4.3 hours (range, 1.0 to 312.0 hours). The median LOV was 8.0 hours (range, 1.5 to 41.0 hours) in the heart-lung recipients, 4.5 hours (range, 2.0 to 47.0 hours) in the bilateral-lung recipients, and 3.5 hours (range, 1.0 to 312.0 hours) in the single-lung recipients. Three transplant recipients, all with primary pulmonary hypertension, were prematurely extubated and reintubated because of pulmonary edema. Twelve hours after extubation, the median oxygenation index (PaO2/F(I)O2, PaO2 in kilopascal units) was greater than 35. The median ICU length of stay for all transplant recipients was 4 days (range, 2 to 270 days).

CONCLUSION

The postoperative use of CPAP and TEA is associated with early and safe tracheal extubation after LTx and may shorten ICU stay.

Acute and chronic effects of bilateral lung transplantation without cardiopulmonary bypass on the first transplanted lung

BACKGROUND

Bilateral lung transplantation (BLT) without cardiopulmonary bypass (CPB) may exacerbate reperfusion injury to the initially engrafted lung because of increases in pulmonary flow during implantation of the second graft.

METHODS

In a retrospective review of 23 BLT patients, we hypothesized that BLT without CPB injures the first transplanted lung measured by acute and late graft dysfunction compared to the second transplanted lung. Of the 23 BLT, 19 underwent transplantation without CPB while 4 patients were placed on CPB secondary to hemodynamic instability.

RESULTS

Acute graft function was assessed by radiographic scoring of lung quadrants (blinded radiologist; 0 = no infiltrate; 1 = infiltrate; maximum = 2 per lung) and by arterial/alveolar oxygen tension ratios (PaO2/ FiO2) ratios. Late graft function was evaluated by quantitative perfusion scan. Lung perfusion was graded as abnormal if less than 50% on the right or less than 45% on the left (Fisher's exact). Radiographic scores were not different between first and second implanted lungs at 1 and 24 hours, PaO2/FiO2 ratios at 1 and 24 hours were 273+/-26 and 312+/-23, respectively, and perfusion scans at 3 and 12 months revealed normal differential blood flow.

CONCLUSIONS

These findings suggest no acute or chronic differences occur between the first or second transplanted lung completed without CPB.

Primary graft failure following lung transplantation

STUDY OBJECTIVES

To determine the incidence of primary graft failure (PGF) following lung transplantation, assess possible risk factors, and characterize its effect on outcomes.

METHODS

Retrospective review of 100 consecutive patients undergoing lung transplantation at the University of Pennsylvania Medical Center. Fifteen patients meeting diagnostic criteria for PGF (PGF+ group) were compared with 85 patients without this complication (PGF- group).

RESULTS

The incidence of PGF was 15%. There was no significant difference in age, sex, underlying pulmonary disease, preoperative pulmonary artery systolic pressure, type of transplant, allograft ischemic times, use of cardiopulmonary bypass, or use of postoperative prostaglandin E1 infusion between the PGF+ and PGF- groups. Induction therapy with antilymphocyte globulin was used less frequently in the PGF+ group (p<0.005). Duration of mechanical ventilatory support was 36+/-43 days vs 4+/-6 days for the PGF+ and PGF- groups, respectively (p<0.0001). Hospital stay was significantly longer in the PGF+ group, averaging 75+/-105 days, compared with 27+/-38 days in the PGF group (p<0.005). One-year actuarial survival for the PGF+ group was only 40% compared with 69% for the PGF- group (p<0.005). Five of the six PGF+ survivors were ambulatory by 1 year; three were completely independent while two continued to require assistance with activities of daily living. Six-minute walk test distance among the ambulatory patients averaged 883+/-463 feet (range, 200 to 1,223 feet) compared with 1513+/-424 feet for the PGF- group (p<0.005). Among the subset of survivors who underwent single lung transplantation for COPD, the mean percent predicted FEV1 at 1 year was 43% for the PGF+ group and 55% for the PGF- groups, but this difference was not statistically significant.

CONCLUSIONS

PGF is a devastating postoperative complication, occurring in 15% of patients in the current series, and it is associated with a high mortality rate, lengthy hospitalization, and protracted and often compromised recovery among survivors.

Lung transplantation for cystic fibrosis

Cystic fibrosis (CF) is an inherited disease in which the fundamental physiological defect is failure of cAMP regulation of chloride transport. More than 90% of patients with CF will die of chronic, suppurative, obstructive lung disease, with the median survival in the United States currently being 29 years of age. Currently, although other therapies are being aggressively investigated, bilateral lung transplantation offers the only hope for short-term and mid-term survival in patients with CF and end-stage pulmonary disease. Since 1989, 103 bilateral sequential lung transplants (BLT) for CF have been performed at our institution (46 pediatric, 48 adult, 9 redo) at a mean age of 21+/-10 years. Cardiopulmonary bypass was used in all but one pediatric (age <18) transplantation, and in 15% of adults. The hospital mortality rate was 4.9%, with 80% of early deaths related to infection. Bronchial anastomotic complications occurred with equal frequency in the pediatric and the adult populations (7.3%). One- and 3-year actuarial survival rates are 84% and 61%, respectively (no significant difference between pediatric and adult age groups; average follow-up 2.1+/-1.6 years). Mean forced expiratory volume in 1 second increased from 25%+/-9% pretransplantation to 79%+/-35% 1 year posttransplantation. Acute rejection occurred 1.7 times per patient-year, with the majority of these episodes taking place the first 6 months posttransplantation. Need for treatment of lower respiratory infections occurred 1.2 times per patient in the first year after transplantation. Actuarial freedom from bronchiolitis obliterans was 63% at 2 years and 43% at 3 years. Redo transplantation was performed only in the pediatric population, and was associated with an early mortality of 33%. Eight living donor transplants (4 primary transplants, 4 redo transplants) were performed with an early survival of 87.5%. Patients with end-stage CF can undergo BLT with morbidity and mortality comparable with that observed in pulmonary transplantation for other disease entities.

Cardiopulmonary bypass is associated with early allograft dysfunction but not death after double-lung transplantation

OBJECTIVES

To assess the effect of cardiopulmonary bypass on allograft function and recipient survival in double-lung transplantation.

METHODS

Retrospective review of 94 double-lung transplantations.

RESULTS

Cardiopulmonary bypass was used in 37 patients (CPB); 57 transplantations were accomplished without bypass (no-CPB). Bypass was routinely used for patients with pulmonary hypertension (n = 27) and for two recipients undergoing en bloc transplantation. Cardiopulmonary bypass was required in eight (12.3%) of the remaining 65 patients. Mean ischemic time was longer in the CPB group (346 vs 315 minutes, p = 0.04). The CPB group required more perioperative blood (11.4 vs 6.0 units, p = 0.01). Allograft function, assessed by the arterial/alveolar oxygen tension ratio, was better in the no-CPB group at 12 and 24 hours after operation (0.54 vs 0.39 at 12 hours, p = 0.002; and 0.63 vs 0.38 at 24 hours, p = 0.001). The CPB group had more severe pulmonary infiltrates at both 1 and 24 hours (p = 0.005). Diffuse alveolar damage was more common in the CPB group (69% vs 35%, p = 0.002). Median duration of intubation was longer in the CPB group (10 days) than in the no-CPB group (2 days, p = 0.002). The 30-day mortality rate (13.5% vs 7.0% in the CPB and no-CPB groups) and 1-year survival (65% vs 67%, CPB and no-CPB) were not significantly different.

CONCLUSIONS

In the absence of pulmonary hypertension, cardiopulmonary bypass is only occasionally necessary in double-lung transplantation. Bypass is associated with substantial early allograft dysfunction after transplantation.

The Utility of Nitric Oxide in the Postoperative Period

Inhaled nitric oxide (iNO) is a pulmonary-selective vaso dilator with minimal bronchodilator activity in humans. NO also inhibits platelet and neutrophil activation and adhesion and inhibits ischemia-reperfusion injury. The pulmonary vasodilatory property of iNO causes a reduc tion in pulmonary vascular resistance and improvement in arterial oxygenation in a wide spectrum of diseases characterized by pulmonary hypertension and hypox emia. Promising examples of diseases for which NO may provide beneficial physiologic effects are primary and secondary pulmonary hypertension, right ventricu lar failure, cardiac transplantation, pulmonary embo lism, protamine reactions, acute respiratory distress syndrome, lung transplantation and, perhaps, chronic obstructive airways disease. The usefulness of iNO may be improved by concomitant therapy with pulmonary- selective intravenous vasoconstrictors (eg, Almitrine; Vectarian, Neuilly, France) and cGMP phosphodiester ase V inhibitors (eg, Zaprinast; Research Biochemicals International, Natick, MA). Almitrine improves oxygen ation, synergistically with iNO, and may be useful in disease states characterized primarily by hypoxemia. Zaprinast may be useful for weaning iNO and avoidance of rebound pulmonary hypertension.

Pediatric and adult lung transplantation for cystic fibrosis

OBJECTIVE

This paper was undertaken to review the experience at our institution with bilateral sequential lung transplantation for cystic fibrosis.

METHODS

Since 1989, 103 bilateral sequential lung transplants for cystic fibrosis have been performed (46 pediatric, 48 adult, 9 redo); the mean age was 21 +/- 10 years. Cardiopulmonary bypass was used in all but one pediatric (age <18) transplant, and in 15% of adults.

RESULTS

Hospital mortality was 4.9%, with 80% of early deaths related to infection. Bronchial anastomotic complications occurred with equal frequency in the pediatric and the adult populations (7.3%). One- and 3-year actuarial survival are 84% and 61%, respectively (no significant difference between pediatric and adult age groups; average follow-up 2.1 +/- 1.6 years). Mean forced expiratory volume in 1 second increased from 25% +/- 9% before transplantation to 79% +/- 35% 1 year after transplantation. Acute rejection occurred 1.7 times per patient-year, with most episodes taking place within the first 6 months after transplantation. The need for treatment of lower respiratory tract infections occurred 1.2 times per patient in the first year after transplantation. Actuarial freedom from bronchiolitis obliterans was 63% at 2 years and 43% at 3 years. Redo transplantation was performed only in the pediatric population and was associated with an early mortality of 33%. Eight living donor transplants (four primary transplants, four redo transplants) were performed with an early survival of 87.5%.

CONCLUSION

Patients with end-stage cystic fibrosis can undergo bilateral lung transplantation with morbidity and mortality comparable to that seen in pulmonary transplantation for other disease entities.

Perioperative management of patients undergoing lung transplantation

This review focuses on recent developments in the perioperative management of patients undergoing lung transplantation. Relevant current literature and the experience of the Munich Lung Transplant Group were taken into consideration. Recent advances include the use of inhalational nitric oxide for the treatment of early graft dysfunction and the use of aerosolized cyclosporine for the treatment of recurrent and steroid-resistant acute rejection. Opportunistic infections remain a major source of morbidity and mortality in lung transplant recipients.

Anesthesia for bilateral sequential lung transplantation: experience of 64 cases

OBJECTIVES

To review the experience of anesthesia for bilateral sequential lung transplantation (BSLTx) and describe factors associated with outcome.

DESIGN

Case series.

SETTING

University hospital.

PARTICIPANTS

Sixty-four adult patients undergoing BSLTx.

INTERVENTIONS

Descriptive and inferential statistical analysis.

MEASUREMENTS AND MAIN RESULTS

Details of anesthetic technique, patient, and perioperative characteristics are presented. Mean (SD) lung allograft ischemic times were 320 (81) minutes for the first lung and 446 (93) minutes for the second lung. Mean (SD) duration of surgery was 8.5(2) hours, and median time to extubation was 28 hours. There was a reduction in the use of cardiopulmonary bypass, from 10 of 19 (53%) in 1992 to 1993 to 10 of 45 (22%) in 1994 to 1996, p = 0.016. There was an association between time to extubation and duration of surgery (Spearman rank correlation, p = 0.33, p = 0.008), but no association with intraoperative fluid administration (p = 0.18, p = 0.16), or inotrope requirements (p = 0.06, p = 0.65). Predictors of in-hospital mortality were preoperative renal impairment (p = 0.034), early reoperation (p = 0.005), and delay in extubation (p = 0.013); and for 12-month mortality was patient age (p = 0.01). The actuarial survival rates were 90%, 73%, and 58% at 30 days, 1 year, and 2 years, respectively.

CONCLUSIONS

Anesthesia for BSLTx is a most challenging procedure, for which maintenance of tissue oxygenation and right ventricular perfusion are essential. Recent advances include use of inhaled nitric oxide, ventilator management that reduces dynamic hyperinflation, and permissive hypercapnia. Analysis of outcome from a large case series such as this enables the anesthesiologist to be more aware of the important features of anesthesia for BSLTx, as well as identify potential areas of improvement.

Cardiopulmonary bypass (CPB) for lung transplantation

Surgeons have often been reluctant to use cardiopulmonary bypass (CPB) during single (SLTx) and double lung (DLTx) transplantation surgery because of the potential adverse sequelae of CPB including haemorrhage and activation of complement leading to sequestration of neutrophils and platelets in the pulmonary capillary bed, endothelial damage, increased capillary permeability and pulmonary oedema. To clarify the effect of CPB on lung transplant recipients, we reviewed our last four years' experience in 74 patients of whom 30 required CPB support. Indications for CPB were mean pulmonary artery pressure of greater than 50 mmHg, haemodynamic instability, hypoxia or hypercarbia. Patients undergoing SLTx were placed on CPB via the femoral artery and vein, while those undergoing DLTx were cannulated in the standard fashion using the ascending aorta and right atrium. All patients were administered aprotinin prior to CPB. Intraoperatively and postoperatively, haemorrhage was not a major problem. The 30-day mortality in the CPB group and the non-CPB group were 20% and 4.6%, respectively which was not statistically significant (p = 0.06). We conclude that CPB during lung transplantation is a safe, effective method to support these severely ill patients and should not be avoided because of concerns over adverse sequelae of CPB on postoperative graft function.

Early lung allograft function in twin recipients from the same donor: risk factor analysis

BACKGROUND

Transplantation of lung allografts from the same donor into 2 recipients ("twinning") provides an opportunity to study recipient and donor factors that influence early allograft function.

METHODS

Twenty-seven pairs of recipients were identified and evaluated using multivariate logistic regression analysis (p < 0.05). Four measures of early graft function were analyzed: alveolar-arterial gradient in the operating room, first alveolar-arterial gradient in the intensive care unit, alveolar-arterial gradient at 24 hours, and days of mechanical ventilation.

RESULTS

Analysis of the pooled data without regard to pairing showed that alveolar-arterial gradient in the operating room was influenced by donor age, length of donor hospitalization, recipient mean pulmonary artery (PA) pressure at unclamping, and transplantation of a left lung. The alveolar-arterial gradient in the intensive care unit was correlated with donor age, donor cause of death, and mean PA pressure on arrival in that unit. Only mean PA pressure remained significant at 24 hours. Days of mechanical ventilation was determined by mean PA pressure on arrival in the intensive care unit, drop in mean PA pressure during operation, and diagnosis of the recipient. In the paired analysis, receiving a left lung, recipient diagnosis (pulmonary hypertension worse than others), and need of cardiopulmonary bypass were significantly associated with immediate graft dysfunction, although these influences did not persist beyond the immediate postoperative period. Donor arterial oxygen tension and time of ischemia were not significant predictors in any analysis.

CONCLUSIONS

Immediate allograft function was associated with donor-related characteristics initially, but these lost importance over the ensuing 24 hours. Recipient PA pressure was an immediate and persisting influence. In the analysis of differences in function between the members of each pair, transplantation of the left lung, recipient diagnosis, and cardiopulmonary bypass were identified, but their influence did not persist beyond the first 6 hours.

Pressure gradient across the pulmonary artery anastomosis during lung transplantation

BACKGROUND

Perioperative monitoring of pulmonary artery (PA) pressures in lung transplant recipients is critical. This report characterizes an intraoperative gradient across the PA anastomosis in a series of patients undergoing bilateral sequential lung transplantation.

METHODS

Hemodynamic measurements were obtained in a series of 10 patients before anesthetic induction, during one-lung ventilation/perfusion of the newly transplanted first lung with the PA catheter proximal and distal to the anastomosis and after arrival in the intensive care unit. The following measurements were recorded: central venous pressure, cardiac output, PA occlusion pressure, and systemic and pulmonary arterial pressures (systolic, diastolic, mean).

RESULTS

Although a systolic pressure gradient of more than 10 mm Hg across the anastomosis was observed in all patients, there was a significant variation in systolic (13 to 59 mm Hg), diastolic (2 to 10 mm Hg), and mean (5 to 27 mm Hg) PA gradients. Mean proximal systolic PA pressure measurements (56.2 +/- 20.6 mm Hg) were greater when compared to measurements obtained distal to the anastomosis (28.6 +/- 10.1 mm Hg, p = 0.001) and to those obtained in the postoperative period (32.1 +/- 9.7 mm Hg, p = 0.004).

CONCLUSIONS

The present study demonstrates that during single-lung ventilation and perfusion, the PA pressure measured proximally may not reflect accurately the pressure distal to the vascular anastomosis.

Improved results of lung transplantation for patients with cystic fibrosis

Patients with cystic fibrosis pose particular challenges for lung transplant surgeons. Earlier reports from North American centers suggested that patients with cystic fibrosis were at greater risk for heart-lung or isolated lung transplantation than other patients with end-stage pulmonary disease. During a 3 1/2 year period, 44 patients with end-stage lung disease resulting from cystic fibrosis underwent double lung transplantation at this institution. During the same interval, 18 patients with cystic fibrosis died while waiting for lung transplantation. The ages of the recipients ranged from 8 to 45 years, and mean forced expiratory volume in 1 second was 21% predicted. Seven patients had Pseudomonas cepacia bacteria before transplantation. Bilateral sequential implantation with omentopexy was used in all patients. There were no operative deaths, although two patients required urgent retransplantation because of graft failure. Cardiopulmonary bypass was necessary in six procedures in five patients and was associated with an increased blood transfusion requirement, longer postoperative ventilation, and longer hospital stay. Actuarial survival was 85% at 1 year and 67% at 2 years. Infection was the most common cause of death within 6 months of transplantation (Pseudomonas cepacia pneumonia was the cause of death in two patients), and bronchiolitis obliterans was the most common cause of death after 6 months. Actuarial freedom from development of clinically significant bronchiolitis obliterans was 59% at 2 years. Results of pulmonary function tests improved substantially in survivors, with forced expiratory volume in 1 second averaging 78% predicted 2 years after transplantation. Double lung transplantation can be accomplished with acceptable morbidity and mortality in patients with cystic fibrosis.