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Biomedical subjects

M A Pozniak

Publications and source records attributed to M A Pozniak.

At least 19 recordsLinked to original sources
PubMed2000

Phlegmasia cerulea dolens with compartment syndrome: a complication of femoral vein catheterization.

OBJECTIVE: Central venous catheterization is commonly performed in the critically ill. The femoral vein is widely accepted as an insertion site with complications thought to be comparable to other central access sites. We used serial ultrasound examinations with Doppler to examine the evolution of a heretofore undescribed complication of femoral vein catheterization, phlegmasia cerulea dolens with compartment syndrome. DESIGN: Serial ultrasounds were performed in patients before the insertion of femoral venous catheters and sequentially every 48 hrs while the catheters were in place. The noncatheterized leg served as a control. SETTING: A trauma and life support center of a tertiary multidisciplinary critical care unit. PATIENT: A 32-yr-old man with respiratory failure as a consequence of a severe community-acquired pneumonia that required central venous access for antibiotics because no peripheral sites could be obtained. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The initial ultrasound examination of both legs before femoral catheter insertion revealed no sign of venous thrombosis. Ultrasound of the catheterized leg at 48 hrs revealed a small nonocclusive thrombosis, whereas the opposite leg remained normal. At 72 hrs, the catheterized leg had clinical and ultrasonographic evidence of a massive thrombosis. A compartment syndrome defined by pressure measurements soon ensued and required emergent surgical release. CONCLUSIONS: This case report and a review of the available literature suggest that thrombosis associated with femoral vein catheterization should be considered when clinicians decide where to obtain central venous access when multiple sites are available. This report also suggests the utility of serial ultrasound examinations to define clinically nonapparent thrombosis as an early indicator of a potentially catastrophic complication.

Adult↗
PubMed2000

Intraoperative sonographic assessment of graft patency during extracranial-intracranial bypass.

Extracranial-intracranial (EC-IC) bypass may be necessary to facilitate treatment of unclippable posterior circulation fusiform aneurysms. Although intraoperative digital subtraction angiography (DSA) allows assessment of graft patency, this technique, because of difficulties inherent in performing selective catheterization and angiography in the operating room, has limitations. Duplex sonography, in contrast, is easily performed, and provides information regarding graft patency and blood flow direction during EC-IC bypass procedures. This latter information proved useful in determining the time of parent artery occlusion after two EC-IC bypass procedures performed for treatment of a fusiform midbasilar artery aneurysm.

Adult↗
PubMed1999

Computed tomographic angiography in the preoperative evaluation of potential renal transplant donors.

The preoperative screening of potential renal transplant donors has undergone a major evolution with the introduction of computed tomographic angiography. With computed tomographic angiography, the radiologist is able to provide the surgeon with precise and valuable preoperative details of renal arterial and venous anatomy. In addition, computed tomographic angiography provides valuable information regarding the renal parenchyma and adjacent organs. This helps reduce the risks and complications associated with transplant surgery and improves the chances of a successful outcome. Helical computed tomographic angiography is rapidly replacing intravenous urography and conventional angiography as the imaging modality of choice for evaluating renal donors.

Angiography↗
PubMed1998

Sonography of testicular tumors and tumor-like conditions: a radiologic-pathologic correlation.

Malignant testicular tumors are an important clinical problem, and ultrasound is the most frequently ordered imaging modality once a palpable scrotal mass is discovered. Numerous articles discussing the role of ultrasound in the evaluation of testicular pathology have confirmed the value of preoperative imaging. This article presents a review of imaging literature regarding testicular neoplasms, with an emphasis on correlation of gross and microscopic tumor pathology and imaging findings. Also included are sections on anatomy, epidemiology, histogenesis, and tumor markers.

Adult↗
PubMed1996

A randomized comparison of iodixanol and iohexol in adult body computed tomography scanning.

RATIONALE AND OBJECTIVES: We compared the safety and imaging efficacy of iodixanol-270 (270 mg I/ml), iodixanol-320 (320 mg I/ml), both of which are isosmolal to blood, and iohexol-300 (300 mg I/ml) for body computed tomography (CT) scanning. METHODS: One hundred twenty-six patients from the University of Wisconsin Hospital and Temple University Hospital scheduled to undergo body CT examinations were randomly assigned to receive either iodixanol-270, iodixanol-320, or iohexol-300. Patients were monitored with questioning and vital signs before injection, immediately after injection, and at 24 and 48 hr. Extensive laboratory evaluation also was performed. RESULTS: No serious reactions or deaths occurred in any group. The occurrence of overall minor adverse events (usually warmth, headache, taste distortion, rash) was similar for the different groups. Laboratory results showed no significant difference across groups. There was no significant difference in image quality detected among groups. CONCLUSION: There was no detectable difference in safety and imaging efficacy among the three contrast groups in this study. However, patients from the University of Wisconsin experienced significantly less injection discomfort with iodixanol-270 than with iohexol-300. Large clinical studies may more definitively determine the presence and nature of the relative advantages of iodixanol compared with currently available ionic and nonionic contrast agents.

Contrast Media↗
PubMed1996

Conventional color Doppler velocity sonography versus color Doppler energy sonography for the diagnosis of acute experimental torsion of the spermatic cord.

OBJECTIVE: We compared color Doppler velocity sonography and color Doppler energy sonography for the diagnosis of spermatic cord torsion in a canine model and determined the degree of torsion necessary to acutely halt testicular blood flow. MATERIALS AND METHODS: Spermatic cord torsion was created in five dogs by exposing and rotating the ipsilateral testis 0 degree, 180 degrees, 270 degrees, 360 degrees, 450 degrees, and 540 degrees. Detorsion followed. The testicles were scanned at each torsion stop using both color Doppler velocity sonography and color Doppler energy sonography. Doppler parameters were optimized (by phantom and test scans) and maintained at a tolerable noise level throughout the experiment. Readers who were unaware of the degree of torsion compared flow in the rotated and contralateral control testes. RESULTS: Flow became undetectable by color Doppler velocity sonography and color Doppler energy sonography at 450 degrees in four of five cases and at 540 degrees in one of five cases. We found no significant difference between the velocity and the energy techniques for detecting this absence of flow (p > .05, Wilcoxon test). We found a significant difference in degree of flow for both techniques when comparing controls and all degrees of torsion combined (p < .006, Mann-Whitney test), but significance was achieved at lesser degrees of torsion with the velocity technique than with the energy technique (180 degrees and 360 degrees, respectively, Wilcoxon test). CONCLUSION: Color Doppler energy sonography was not significantly more sensitive than color Doppler velocity sonography for the diagnosis of spermatic cord torsion in this model. Complete occlusion of arterial inflow occurred at 450-540 degrees of torsion.

Animals↗
PubMed1995

Interleukin-2-induced splenic enlargement.

BACKGROUND: Splenomegaly in patients with cancer raises the suspicion of tumor involvement. Splenic enlargement in the absence of splenic metastases, however, has been reported in patients treated with interleukin-2 (IL-2) immunotherapy. This study characterizes the change in spleen size that occurred in 42 patients treated with IL-2 between 1989 and 1993 for nonhematologic malignancies. METHODS: Computed tomography (CT) scans before and during immunotherapy were available for review on all 42 patients and after immunotherapy on 16 of these patients. The splenic index was measured for each CT by a single reader blinded to the time course of IL-2 therapy. RESULTS: Mean splenic index increased 64.1% from 646 cm3 (standard deviation [SD], 387) pre-IL-2 to 1059 cm3 (SD, 534) during therapy with IL-2 (P < 0.0001). The splenic index remained elevated at 1112 cm3 (SD, 633) after completion of IL-2 therapy. CONCLUSIONS: Splenomegaly, temporally associated with IL-2 therapy for nonhematologic malignancies, is likely to represent a sequela of therapy and not tumor progression.

Adult↗
PubMed1995

Imaging of pancreas transplants.

The pancreas transplant is difficult to monitor both clinically and by imaging. Complications such as thrombosis, infection, pancreatitis, bleeding, anastomotic leak, or rejection may quickly progress to transplant failure. Ultrasound, CT, MR imaging, fluoroscopy, nuclear scintigraphy, and angiography may be used to help define the etiology of transplant compromise; however, all have marked limitations, and none has proved to be the study of choice. The surgeon and radiologist must carefully coordinate clinical suspicion with the strengths of the various modalities to optimize a timely diagnosis.

Humans↗
PubMed1995

Compatibility of adaptive responses with combining strength and endurance training.

Impairment in strength development has been demonstrated with combined strength and endurance training as compared with strength training alone. The purpose of this study was to examine the effects of combining conventional 3 d.wk-1 strength and endurance training on the compatibility of improving both VO2peak and strength performance simultaneously. Sedentary adult males, randomly assigned to one of three groups (N = 10 each), completed 10 wk of training. A strength-only (S) group performed eight weight-training exercises (4 sets/exercise, 5-7 repetitions/set), an endurance-only (E) group performed continuous cycle exercise (50 min at 70% heart rate reserve), and a combined (C) group performed the same S and E exercise in a single session. S and C groups demonstrated similar increases (P < 0.0167) in 1RM squat (23% and 22%) and bench press (18% for both groups), in maximal isometric knee extension torque (12% and 7%), in maximal vertical jump (6% and 9%), and in fat-free mass (3% and 5%). E training did not induce changes in any of these variables. VO2peak (ml.kg-1.min-1) increased (P < 0.01) similarly in both E (18%) and C (16%) groups. Results indicate 3 d.wk-1 combined training can induce substantial concurrent and compatible increases in VO2peak and strength performance.

Adaptation, Physiological↗
PubMed1994

Minor vascular anatomy of the abdomen and pelvis: a CT atlas.

With the early generations of computed tomographic (CT) scanners, interpretation of abdominal and pelvic scans focused on the solid organs, hollow viscera, and retroperitoneum. Attention to blood vessels generally was given only to the aorta and inferior vena cava and their larger branches. The newer generations of scanners allow rapid acquisition of high-resolution images during the vascular phase of mechanical bolus injection of intravenous contrast material. Visualization of second-order vascular branches has thus become routine. Recent improvements in software allow real-time reconstruction of data in multiple planes, which enables demonstration of long segments of vessels within a single image. Approximately 7,000 abdominal and pelvic CT scans were reviewed with attention to vascular detail. Cases are presented that illustrate peripancreatic, perigastric, parietal, and hypogastric vessels; fetal remnants and structures that may be mistaken for vessels; and collateral pathways of both arterial and venous flow. With increasing use of helical CT scanning, smaller vessels can be identified with greater confidence. Knowledge of normal CT vascular anatomy facilitates understanding of collateral pathways when vessel engorgement is perceived.

Abdomen↗