CLINICAL ASPECTS OF LUNG TRANSPLANTATION

CT findings of pneumonia after lung transplantation

OBJECTIVE

The purpose of this study was to describe the CT findings of pneumonia in patients who had undergone lung transplantation and to determine if specific imaging features existed for the different infectious organisms.

MATERIALS AND METHODS

The authors retrospectively reviewed the medical records of 262 patients with transplanted lungs at two lung transplantation centers. Patients with a documented pneumonia and correlating abnormal findings on CT (39 patients with 45 pneumonias) were included in the study. RESULTS. Of 45 pneumonias, Cytomegalovirus (n = 15), Pseudomonas (n = 7), and Aspergillus (n = 8) organisms were the most common single responsible infectious agents. The most common CT findings of pneumonia consisted of consolidation (n = 37; 82%), ground-glass opacification (n = 34; 76%), septal thickening (n = 33; 73%), pleural effusion (n = 33; 73%), and multiple (n = 25; 56%) or single (n = 2; 4%) nodules. No significant difference in the prevalence of findings was revealed among bacterial, viral, and fungal pneumonias (p >.05, chisquare test). Of 25 pneumonias in patients with a single transplanted lung, parenchymal abnormalities involved both lungs in 12 (48%), only the transplanted lung in 11 (44%), and only the native lung in two (8%).

CONCLUSION

The manifestations revealed on CT of bacterial, viral, and fungal pneumonia after lung transplantation are similar, consisting of a combination of consolidation, ground-glass opacification, septal thickening, pleural effusion, or multiple nodules. Therefore, these findings cannot be used to suggest the infectious organisms in this patient population.

Imaging of lung transplantation

Lung transplantation is an accepted treatment for a large number of end-stage pulmonary diseases. There are several complications that pertain specifically to lung transplant recipients, including airway ischemia, reperfusion edema, infections, acute rejection, obliterative bronchiolitis, and other postoperative problems relating to surgical technique and immuno-suppressive therapy. Imaging procedures play an important role in the diagnosis and management of these problems.

Perioperative management of lung volume reduction patients

Over the last 2 to 3 years, surgical lung volume reduction via sternotomy or thoracoscopy has been widely explored as an alternative to improve dyspnea, exercise tolerance, and lung mechanics in patients with severe emphysema. In this article, the authors describe the intra- and postoperative management of patients with severe airflow obstruction who undergo this procedure. Anesthesia techniques, extubation, ventilatory management, and overall medical and surgical care are reviewed. The most common postoperative complications also are reviewed, and management of these complications is discussed.

Predicting ICU length of stay following single lung transplantation

STUDY OBJECTIVE

The aim was to identify potential predictors of ICU length of stay (LOS) for single lung transplant patients.

DESIGN

Retrospective chart review.

SETTING

University medical center.

PATIENTS

All single lung transplant recipients for 1992 and 1993 at our institution.

RESULTS

Data were collected from 69 patients. The median ICU LOS was 5 days, and this was highly correlated with the duration of mechanical ventilation. The mean acute physiology and chronic health evaluation (APACHE II) score was 10. Patients with pulmonary hypertension had the longest ICU LOS. Similarly, patients with a measured transpulmonary gradient of 20 mm Hg or less had a significantly shorter ICU LOS. Patients with an immediate postoperative PaO2/fraction of inspired oxygen (FIo2) ratio greater than 200 mm Hg and a flow mismatch between the two lungs of 30% or less also had a significantly shorter ICU LOS. Positive and negative predictive values for the immediate postoperative PaO2/FIo2 ratio of 200 mm Hg or less were 77% for an ICU LOS greater than 5 days, and the calculated receiver operating characteristic (ROC) curve area was 0.74.

CONCLUSION

Overall, the immediate postoperative PaO2/FIo2 ratio of 200 mm Hg or less had the best positive and negative predictive values as well as the highest ROC curve area for predicting an ICU LOS greater than 5 days.

Right ventricular function in patients with severe COPD evaluated for lung transplantation. Lung Transplant Group

Right ventricular function was measured in ten patients with severe COPD (mean FEV1 = 0.48 +/- 0.2 L/s) as part of an evaluation for single lung transplant (SLT). Right ventricular ejection fraction (RVEF) was determined by two methods: first-pass radionuclide scan by multigated acquisition (MUGA) and by using a fast thermistor tipped RVEF/volumetric pulmonary artery catheter. None of the patients had clinical evidence of active right heart failure, although mild resting pulmonary hypertension (mean pulmonary artery pressure [PAP] = 24 +/- 4 mm Hg) that worsened with minimal exercise (mean PAP = 39 +/- 11 mm Hg) was present. There was a significant difference in RVEF measured by the two methods (mean MUGA RVEF = 57 +/- 10%, mean catheter RVEF = 27 +/- 8%; p < 0.00005). RVEF determined by both methods was correlated with hemodynamic and gas exchange variables obtained during rest and at maximal exercise. There were significant, yet inverse, correlations between RVEF measured by catheter and cardiac index measured during exercise (CIex), as well as with exercise pulmonary vascular resistance index (PVRI). There were no significant correlations found between MUGA RVEF and any gas exchange or hemodynamic variables. Significant correlations were found with the catheter-measured right ventricular end-diastolic volume (RVEDV) and CIex (r = 0.9 p < 0.005), with maximal oxygen consumption during exercise (VO2max) (r = 0.86 p < 0.0025), with exercise stroke volume index (SVI) (r = 0.76 p < 0.01), and exercise central venous pressure (CVP) (r = 0.62 p < 0.05). Echocardiographic studies revealed right ventricular dilatation and mild tricuspid regurgitation (TR) in all patients. The strong correlation between RVEDV, CIex, and VO2max supports the concept that in these patients, as long as there is no clinical evidence of right heart failure (resting CVP still within normal limits), those with the largest RVEDVs use the Frank Starling principle to their best advantage to remain more functional.(ABSTRACT TRUNCATED AT 400 WORDS)