S. Baldi

A Way to Select on Clinical Grounds Patients with High Risk for Pulmonary Embolism: A Retrospective Analysis in a Nested Case-Control Study

We studied 196 patients with suspicion of pulmonary embolism (PE), subsequently confirmed in 98 by positive pulmonary angiography and excluded in 98 by normal or near-normal perfusion lung scan. Patients had a clinical questionnaire for history, and, soon after. a radiograph, blood gas analysis, and an ECG. Clinical and instrumental signs were matched in patients with confirmed and unconfirmed PE to find those more frequent in embolic patients and, thus, more characteristic of PE. The following were: previous PE, immobilization and thrombophlebitis (p < 0.05); dyspnea and cough (p < 0.05); enlarged descending pulmonary artery (DPA), enlarged right heart, pulmonary infarction, Westermark sign (p < 0.001), and elevated diaphragm (p < 0.05); hypoxemia. No ECG sign was more frequent in PE. Thereafter, all variables were processed separately with a logistic multiple regression analysis and those significantly associated to PE were tested in a final logistic model that was able to predict the actual result of angiography or scintigraphy; accordingly, previous PE, immobilization, thrombophlebitis, enlarged DPA, pulmonary infarction, Westermark sign, hypoxemia were significantly associated with a high risk of PE (from 2.8 to 15 times greater than in patients without these signs). Therefore, we may conclude that clinical assessment and noninvasive tests may help to detect patients at higher risk for PE where heparin coverage should be started while waiting for conclusive diagnostic procedures.

Influence of bulla volume on postbullectomy outcome.

OBJECTIVE To quantify the contribution of the resected volume and the presence of associated, functionally significant emphysema to the postoperative improvement of pulmonary function after resection of giant lung bullae. DESIGN Patients undergoing elective surgery for giant bullae who had had complete pulmonary function and radiographic studies performed were reviewed retrospectively. SETTING All 25 patients underwent surgery at the thoracic surgery unit of the University of Pisa, Pisa, Italy. METHODS Pulmonary function was assessed before and 12 months after surgery. On the chest radiograph, the location of bullae, and the signs of compression and emphysema were evaluated. The radiographic total lung capacity (TLC(x-ray)) and the volume of bullae were measured according to the ellipse method. Postoperatively, functional and radiographic changes were analyzed. The percentage change in forced expiratory volume in 1 s (Delta FEV(1)%) after surgery was the main outcome measure. The influence of factors related to emphysema and bulla volume on the functional improvement postbullectomy was assessed by stepwise multiple regression. RESULTS Before surgery, the TLC(x-ray) overestimated the TLC measured by nitrogen washout, with a mean difference between the two measurements of 1.095 L. A close relationship was found between the TLC(x-ray) and the plethysmographic TLC (n=6; r=0.95). After surgery, dyspnea lessened (P<0.05) and FEV(1) increased (P<0.01). Statistically, the radiographic bulla volume was the single most important factor determining the Delta FEV(1)% (r=0.80, P<0.0001). CONCLUSIONS These findings suggest that the preoperative size of bullae is the most important contributor to the improvement in ventilatory capacity after bullectomy, and that it is possible to predict the expected increase of postoperative FEV(1) from preoperative bulla volume.