Factors influencing pneumothorax rate at lung biopsy: are dwell time and angle of pleural puncture contributing factors?

PURPOSE: To study factors that may influence pneumothorax and chest tube placement rate, especially needle dwell time and pleural puncture angle. MATERIALS AND METHODS: In 159 patients, 160 coaxial computed tomography (CT)-guided lung biopsies were performed. Dwell time, the time between pleural puncture and needle removal, was calculated. The smallest angle of the needle with the pleura ("needle-pleural angle") was measured. These and other variables were correlated with pneumothorax and chest tube rates. RESULTS: One hundred fifty biopsies were included. There were 58 (39%) pneumothoraces (14 noted only at CT), with eight (5%) biopsies resulting in chest tube placement. Longer dwell times (mean, 29 minutes; range, 12-66 minutes) did not correlate with pneumothoraces (P =.81). Smaller needle-pleural angles (< 80 degrees) [corrected], decreased forced expiratory volume in 1 second to vital capacity ratio (<50%), lateral pleural puncture, and lesions along fissures were associated with higher [corrected] pneumothorax rates (P <.05). Emphysema along the needle path, pulmonary function tests showing ventilatory obstruction, and lesions along fissures predisposed patients to chest tube placement (P <.05). Pleural thickening and prior surgery were associated with lower pneumothorax rates (P <.05). CONCLUSION: Longer dwell times do not correlate with pneumothorax and should not influence the decision to obtain more biopsy samples. A shallow pleural puncture angle may increase the pneumothorax rate.

CT manifestations of respiratory syncytial virus infection in lung transplant recipients.

PURPOSE: The purpose of our study was to evaluate CT findings during respiratory syncytial virus (RSV) infection in lung transplant recipients and to identify sequelae. METHOD: Thirty-nine CT scans prior to, during, and following acute infection in 10 lung transplant recipients were reviewed. Abnormalities that were new from baseline observations and occurred within 4 weeks of diagnosis were defined as acute. Chronic findings were defined as those present >4 weeks after diagnosis. RESULTS: Findings in nine patients were ground-glass (seven), air-space (five), and tree-in-bud (four) opacities and acute bronchial dilatation (four) and wall thickening (four). Patients lacked pleural effusions or lymph node enlargement. Five of seven patients with follow-up exams had new air trapping (three), persistent bronchial dilatation (three), and thickening (two). Three and 2 of the 10 patients developed bronchiolitis obliterans syndrome and obliterative bronchiolitis, respectively. CONCLUSION: During acute infection, patients commonly had ground-glass opacities but lacked pleural effusions and lymph node enlargement. There can be chronic sequelae after infection.

Acute pulmonary embolism: assessment of helical CT for diagnosis.

PURPOSE: To determine the sensitivity and specificity of helical computed tomography (CT) for the diagnosis of acute pulmonary embolism. MATERIALS AND METHODS: This prospective study included 47 patients who underwent pulmonary arteriography for evaluation for possible acute pulmonary embolism. Tailored helical CT and pulmonary arteriography were performed within 24 hours of each other. Each CT scan was interpreted by two chest radiologists, blinded to arteriographic results, at two institutions. CT scan interpretations were compared with findings on bilateral selective pulmonary arteriograms interpreted by two vascular radiologists at one institution. RESULTS: Fifteen (32%) of 47 patients had angiographically proved pulmonary embolism. For the readers at the first institution, helical CT had 60% sensitivity, 81% specificity, 60% positive predictive value, 81% negative predictive value, and 75% overall accuracy. For the readers at the second institution, helical CT had 53% sensitivity, 97% specificity, 89% positive predictive value, 82% negative predictive value, and 83% accuracy. CONCLUSION: Detection of pulmonary embolism with helical CT may be less accurate than previously reported. Given its high specificity but relatively low sensitivity, helical CT may not have the ideal attributes of a first-line imaging study for the diagnosis of pulmonary embolism.

Power injection of peripherally inserted central catheters.

PURPOSE: To study the tolerance of peripherally inserted central catheters (PICCs) of varying sizes and materials to power injection of radiographic contrast agents. MATERIALS AND METHODS: Eight different models of silicone and five different models of polyurethane single-lumen PICCs were injected with increasing rates of iothalamate 60% with use of a power injector. Tolerated and bursting rates and pressures were recorded. RESULTS: There was a wide range of tolerated rates and pressures, depending on the inner and outer diameters of the catheters and on the catheter material. Silicone PICCs tolerated rates between 0.4 and 7.0 mL/sec and polyurethane PICCs tolerated rates between 0.6 and 10.2 mL/sec, depending on the specific catheter. The 5-F silicone PICCs and the 4-F and 5-F polyurethane PICCs tested all tolerated rates greater than 4 mL/sec. Silicone catheters tolerated pressures between 107 and 184 psi, and polyurethane catheters tolerated pressures between 160 and 314 psi. CONCLUSIONS: Larger single-lumen silicone and polyurethane PICCs may be suitable for power injection of contrast agents.

Malfunction of implantable cardioverter defibrillators placed by a nonthoracotomy approach: frequency of malfunction and value of chest radiography in determining cause.

OBJECTIVE: The purpose of this study was to determine the frequency of system malfunction in patients with nonthoracotomy implantable cardioverter defibrillators and to assess the role of chest radiography in detecting and determining the cause of malfunction. MATERIALS AND METHODS: The study population consisted of 300 consecutive patients in whom implantable cardioverter defibrillators were implanted using an initial nonthoracotomy approach between September 1990 and October 1994. Transvenous electrodes were placed via the subclavian or cephalic vein under local anesthetic. Intraoperative testing, pulse generator implantation, and, if necessary, subcutaneous patch or extrapericardial patch placement via thoracotomy were done in the operating room under general anesthetic. Follow-up consisted of routine device interrogation every 2-3 months and annual chest radiography. Chest radiographs were obtained more often if patients were symptomatic or if results of device interrogation were abnormal. RESULTS: Patients were followed up for a mean +/- SD of 19 +/- 14 months following implantation. Implantable cardioverter-defibrillator malfunction occurred in 17 patients (6%) during the follow-up period. Of these, 12 (71%) had component abnormalities on chest radiographs. Patients with radiographically apparent implantable cardioverter-defibrillator abnormalities presented in two discrete time periods after device implantation, early (mean, 35 +/- 14 days) and late (mean, 18 +/- 5 months). CONCLUSION: Malfunction of nonthoracotomy implantable cardioverter-defibrillator systems develops infrequently after device implantation. In most cases, the cause can be identified on chest radiographs.