R. Phillip Burns

Preliminary experience with airway pressure release ventilation in a trauma/surgical intensive care unit.

BACKGROUNDnAirway pressure-release ventilation (APRV) is a pressure-limited, time-cycled mode of mechanical ventilation. The purpose of this study was to evaluate our initial experience with the use of APRV in acutely injured, ventilated patients.nnnMETHODSnSince March 2003, APRV has been used selectively in adult trauma patients with or at risk for acute lung injury/acute respiratory distress syndrome. Data were obtained before and during the 72 hours after switching to APRV. A retrospective analysis of these data was then performed.nnnRESULTSnComplete data were available on 46 of 60 patients (77%) for the first 72 hours of APRV. Before APRV, the average Pao2/Fio2 ratio was 243 and the average peak airway pressure was 28 cm H2O. Peak airway pressure decreased 19% (p = 0.001), Pao2/Fio2 improved by 23% (p = 0.017) and release tidal volumes improved by 13% (p = 0.020) over the course of the analysis.nnnCONCLUSIONnAPRV significantly improved oxygenation by alveolar recruitment and allowed for a reduction in peak airway pressures. This relatively new modality had favorable results and appears to be an effective alternative for lung recruitment in traumatically injured patients at risk for acute lung injury/acute respiratory distress syndrome.

Stereotactic Core-needle Breast Biopsy by Surgeons: Minimum 2-year Follow-up of Benign Lesions

ObjectiveTo evaluate the reliability of stereotactic core-needle breast biopsy (SCNB) performed by surgeons to detect histologically benign tissue. Summary Background DataStereotactic core-needle breast biopsy is widely used to obtain tissue for definitive pathologic diagnosis of mammographically suspicious breast lesions. It has an incidence of malignancy detection similar to that of open biopsy. The potential for sampling error is a concern. Minimal data regarding follow-up and failure rate are available, especially from series performed exclusively by surgeons. MethodsPertinent medical records of all patients who underwent SCNB between April 1995 and October 1997 were reviewed. Breast lesions were classified by mammographic Breast Imaging—Reporting and Data Systems (BI-RADS) categories before SCNB. Benign biopsy specimens were classified as nonproliferative or proliferative. Malignant lesions and those with atypical histopathology by SCNB were excluded from this analysis. All lesions initially reported as benign were followed up mammographically for at least 2 years for any suspicious change requiring repeat biopsy. ResultsDuring the 31-month period, SCNB was performed on 694 lesions in 619 patients. Histologic evidence of malignancy was found in 112 lesions (16%). The initial histologic diagnosis for the remaining 582 lesions was benign. Four hundred lesions were available for follow-up; of these, 373 (93%) were mammographically categorized as BI-RADS 3 (probably benign) or 4 (suspicious). Three hundred forty-three lesions were categorized as nonproliferative and 151 as proliferative (94 had combined nonproliferative and proliferative histology). Follow-up ranged from 24 to 48 months (mean 33 months). During the follow-up period, 87 lesions (21.8%) underwent either image-guided or open biopsy. At the time of follow-up rebiopsy, ductal carcinoma in situ was found in four lesions and infiltrating ductal carcinoma was found in one, for an overall false-negative rate of 4.3% (5/117) and a negative predictive value of 98.8% (395/400). For the five false-negative cases, the interval from initial SCNB to definitive diagnosis ranged from 7 to 36 months. No correlation was found between the type of initial histopathology and development of malignancy. ConclusionsThese results support SCNB as an alternative to open biopsy and show the reliability of SCNB when benign pathology is obtained. However, given the possibility of sampling error and the nature of breast disease, close mammographic and clinical follow-up is necessary. The false-negative rate and negative predictive value in this series compare favorably with those in other reports, supporting the fact that surgeons can confidently use SCNB in the evaluation and treatment of breast disease.

MEDIASTINAL EVALUATION UTILIZING THE REVERSE TRENDELENBURG RADIOGRAPH

When thoracic aortic rupture is suspected, a 45-degree reverse Trendelenburg (RT) anteroposterior (AP) chest radiograph should place the mediastinal structures in a more appropriate position and allow a more accurate evaluation than a supine AP radiograph. One hundred ninety-one consecutive hemodynamically stable adult patients with major blunt thoracic trauma were initially evaluated for mediastinal abnormalities associated with aortic disruption by both supine AP chest radiograph and an AP chest radiograph with the patient in 45-degree RT position. One hundred four patients underwent contrast aortography based on mediastinal abnormalities detected on the supine AP chest radiograph. Twenty of these patients had abnormal aortograms demonstrating traumatic aortic disruption confirmed at surgery. Supine and RT chest radiographs were retrospectively compared in a blinded fashion to evaluate their specificity and positive predictive value for detection of traumatic thoracic aortic rupture. If RT chest radiographic findings had been used to determine the need for further assessment, 29 angiograms (26%) would have been eliminated, specificity would have increased from 52 per cent to 69 per cent, and positive predictive value would have increased from 19 per cent to 27 per cent. Both supine and RT chest radiographs demonstrated mediastinal widening in all 20 patients with abnormal aortograms, with no missed thoracic aortic disruptions (100% sensitivity). This study indicated that the RT chest radiograph may be used instead of the standard supine radiograph as the initial screen for mediastinal evaluation, maintaining a high sensitivity and eliminating the cost and morbidity of many unnecessary aortograms.