Use of universal precautions in interventional radiology: results of a national survey.

OBJECTIVE: To determine current use of universal precautions by practicing interventional radiologists in the United States. METHODS: National survey mailed to interventional radiologists, conducted anonymously in November 1991. Of 1530 survey forms mailed to practicing interventional radiologists, 817 (53%) were returned and 804 (52%) were completed and evaluable. Both academic and private practice settings were represented. RESULTS: Eighty-five percent of respondents had changed their use of infection control measures in the previous 10 years. Of these, 96% cited personal concerns about AIDS as a reason for making changes. Sixty-two percent made changes in response to Centers for Disease Control and Prevention and Occupational Safety and Health Administration recommendations as well. Use of barrier precautions was quite variable. Although 86% of respondents always wore a sterile gown during procedures, only 32% routinely wore a face mask or shield and only 29% of those who did not wear corrective glasses routinely wore protective eye gear during procedures. Seven percent of respondents routinely double gloved for procedures. Twenty percent of reported percutaneous injuries occurred during recapping of used sharps; an additional 6% were related to improper disposal of used sharps. CONCLUSIONS: We conclude that use of universal precautions by interventional radiologists in the United States is variable. Some practices that may lead to preventable injury to health care workers remain common.

Pulmonary embolism: comparison of MR images with radionuclide and angiographic studies.

PURPOSE: To assess the accuracy and potential of magnetic resonance (MR) imaging in evaluation of patients in whom pulmonary embolism is suspected. MATERIALS AND METHODS: Blinded, prospective interpretations of multiphasic, cardiac-gated spin-echo MR images were compared with retrospective chart review in 86 patients in whom pulmonary embolism was suspected. In 64 patients, the presence or absence of pulmonary emboli was established with x-ray angiography (n = 34) or ventilation-perfusion (V-P) scans and concurrent clinical impression (n = 30). RESULTS: In the subgroup with angiographic proof, MR imaging had a sensitivity of 90%, specificity of 77%, positive predictive value of 86%, and negative predictive value of 83%. In 21 patients with intermediate probability of pulmonary embolism on V-P scans and angiograms, MR images enabled diagnosis of pulmonary embolism in 12 of 12 patients (sensitivity, 100%) and absence of pulmonary embolism in seven of nine patients (specificity, 78%). CONCLUSION: MR imaging reliably depicts large and medium-size pulmonary emboli, regardless of infiltrates or effusion; hence, it may clarify findings on V-P scans that show intermediate probability of pulmonary embolism or are at variance with the clinical impression.

Needle-stick injuries and blood contacts during invasive radiologic procedures: frequency and risk factors.

OBJECTIVE: Possible nosocomial transmission of blood-borne pathogens is a serious concern for health care workers and patients alike. Needle-stick injuries and blood contacts pose a risk of pathogen transmission during procedures. We performed a study to determine the frequency of injuries and blood contacts during invasive radiologic procedures and to examine procedure-related factors that may increase risk of injury or exposure. SUBJECTS AND METHODS: A prospective study of needle-stick injuries and blood contacts during invasive radiologic procedures was performed. During a 10-week period, information about procedures was recorded by technologists or physicians, and needle-stick injuries and exposures to patients' blood and body fluids were noted. Data were analyzed with the SAS statistical package. RESULTS: Accidental exposure to patients' blood and body fluids occurred in 15 of 501 cases (3.0%; 95% confidence interval, 1.7-4.9%). Of 729 operators at risk, 15 were exposed (2.0%; 95% confidence interval 1.1-3.3%). Exposure was parenteral in one case and cutaneous in 14. Risk of exposure was correlated with procedure duration (p = .003), but not with emergency vs elective procedure status (p = .796), procedure type (p = .275), or operator experience level (p = .554). Three needle-stick injuries (0.6% of cases) occurred, all with sterile instruments; bleeding occurred in two cases. Risk of injury was correlated only with procedure type (p = .046). In no case was a patient exposed to a physician's blood. CONCLUSION: Whereas cutaneous exposure of physicians to patients' blood was not infrequent, parenteral exposure was rare in this series. Most of the exposures in this study could have been prevented by the use of protective equipment. Patients' contact with physicians' blood did not occur in this study.

HIV and interventional radiology: a national survey of physician attitudes and behaviors.

PURPOSE: The frequency of parenteral and cutaneous exposure to blood or body fluid during interventional radiologic procedures, current use of barrier precautions by interventional radiologists, and physician attitudes about testing for the human immunodeficiency virus (HIV) and related issues were assessed. MATERIALS AND METHODS: An anonymous survey of interventional radiologists was conducted by mail in November 1991. RESULTS: Of 1,530 surveys, 819 (54%) were returned and 806 (53%) were completed and evaluable. Ninety-six percent of respondents (763 of 794) perform procedures in patients infected with HIV. Sixty-nine percent oppose mandatory testing of physicians for HIV. Eighty-seven percent (693 of 797) reported at least one procedure-related injury (range, 0-99; mean, four). Fifty-eight percent of injuries occurred with use of a sharp instrument (381 of 662), 20% were due to needle recapping (133 of 662), and 7% (44 of 662), to improper disposal of a sharp instrument. Contact between a physician's blood and a patient was reported in only one case (0.2%). Eighty-five percent of respondents (671 of 789) changed their use of barrier precautions in the last 10 years; concerns about HIV were cited by 96% as a reason for change. Reported use of barrier measures was highly variable. CONCLUSION: Exposure to patients' blood or body fluid is not infrequent during interventional radiologic procedures. Exposure of patients to the blood or body fluid of health care workers is rare. Use of recommended precautions in interventional radiology is variable, and practices that could lead to preventable injury remain common. Strategies should be developed to reduce risks even further and to encourage universal compliance with government guidelines.

Vascular proximity: is it a valid indication for arteriography in asymptomatic patients?

The role of arteriography in asymptomatic patients with penetrating extremity wounds in proximity to major vessels is controversial. This prospective study was designed to evaluate a precise definition of proximity, determine the incidence of positive arteriograms, and correlate angiographic interpretation with operative findings. Proximity was defined as any wound located within 1 cm of a major vessel. Excluded were patients with a pulse deficit, bruit, thrill, history of arterial hemorrhage, expanding hematoma, nerve deficit, fracture, or significant soft-tissue injury. One hundred sixty arteriograms were performed in 146 patients. One hundred forty-three (89.4%) were true-negatives. Seventeen (10.6%) were suggestive of injury. These included seven (4.4%) true-positive arteriograms, six (3.8%) false-positive studies, and four (2.5%) positive arteriograms in patients who were not operated upon. The angiographic report correlated with operative findings in five (38.5%) of 13 patients. These data confirm the low incidence (4.4%) of vascular injury in asymptomatic patients. The use of extremity angiography when proximity is the sole indication in an asymptomatic patient with a normal vascular examination must be questioned.

Deep venous thrombosis of extremities: role of MR imaging in the diagnosis.

Current noninvasive imaging techniques for diagnosis of deep venous thrombosis (DVT) of extremities are limited in their ability to demonstrate central vein involvement and to distinguish acute from chronic changes. The utility of spin-echo magnetic resonance (MR) imaging for DVT was evaluated in 100 patients suspected of having either upper- (n = 25) or lower-extremity (n = 75) DVT. Ninety-seven patients were imaged successfully. In a subset of 36 patients, prospective comparison of MR imaging with contrast venography revealed a sensitivity of 90%, specificity of 100%, and Kappa level of agreement of .752 (P less than .0001). MR imaging showed more central extent of thrombus than did venography in all five patients with upper-extremity DVT and in 13 of 25 patients (52%) with lower-extremity DVT. Although all patients in the study were evaluated for acute symptoms, 13 of 59 (22%) MR imaging studies positive for DVT demonstrated chronic disease. MR images demonstrated ancillary abnormalities in 18 of 41 (44%) patients who did not have DVT. Thus, MR imaging has a role as the definitive examination when the results of initial screening studies are unsatisfactory, or as a first-line examination if (a) there is suspicion of upper-extremity or pelvic vein thrombosis, (b) there is a history of prior DVT that necessitates distinction of acute from chronic changes, or (c) other tests are unavailable.

Posterior abdominal stab wounds: role of CT evaluation.

Stab wounds to the back present a diagnostic problem, since missed occult abdominal injuries can lead to serious morbidity. In a prospective study of 205 patients, the authors evaluated the usefulness of abdominal computed tomography (CT) in assessment of low-velocity penetrating injury to the back. CT results were classified into three groups. Category 1 included injuries limited to superficial subcutaneous tissue (n = 174); category 2, injuries to the retroperitoneal compartment (n = 18); and category 3, injuries within the peritoneal cavity (n = 13). Fifty patients underwent surgery, including 30 with category 1 injuries, nine with category 2 injuries, and eleven with category 3 injuries. CT categorization of injury, compared with surgical findings in these 50 patients, had a sensitivity of 85% and specificity of 93%. The CT interpretation was considered correct if it demonstrated peritoneal penetration or retroperitoneal injury potentially requiring surgery. The remaining 155 patients were managed nonoperatively, and none had late complications. Abdominal CT is a reliable diagnostic tool in the evaluation of penetrating injury to the back.

The role of abdominal CT in the evaluation of stab wounds to the back.

Two hundred five patients with stab wounds to the back were evaluated with CT scans using both oral and IV contrast material. One hundred sixty-nine patients had a negative scan. Thirty (17.8%) of the 169 patients were operated upon because of clinical concern. Injuries were found in two of these patients: a diaphragmatic injury in one and a combined diaphragmatic and liver injury in the other. None of the 139 patients observed developed any sequelae. Twenty of the 33 patients with a positive CT were taken to the operating room where 16 were found to have a significant injury. Seven of these 16 patients had additional injuries not identified on CT. There were four false positive scans. Thirteen patients with a positive scan and two patients with an equivocal scan were observed based upon clinical judgment. Ten of these 15 patients had minor isolated renal or hepatic injuries seen on scan. None of these developed complications. It is concluded that abdominal computed tomography, with a sensitivity of 89%, specificity of 98%, and accuracy of 97% is a reliable study in the evaluation of patients with stab wounds to the back.

The route to subspecialty accreditation.

Subspecialty training accreditation is a way in which the adequacy of postresidency training can be controlled. The development of subspecialty training accreditation is the purview of the Residency Review Committees (RRCs) of the Accreditation Council for Graduate Medical Education (ACGME). An RRC develops the Special Requirements and the Justification/Impact statement for the subspecialty. These documents are reviewed by all other RRCs, the parent organizations of the sponsoring RRC, and the ACGME and other interested groups. When all suggestions from these groups are answered by the RRC, the Committee for Review of Special Requirements of the ACGME must approve the program. The final step is ACGME approval. The program will then go into effect on the date specified in the Justification/Impact statement. The procedure is complex and time-consuming. However, in the final analysis, a subspecialty program accredited in this fashion will be a solid educational experience for the trainee and should have a well-defined role in the parent institution.

Evaluation of computed tomography and diagnostic peritoneal lavage in blunt abdominal trauma.

Three hundred one hemodynamically stable patients with equivocal abdominal examinations following blunt abdominal trauma had a CT scan followed by DPL. Both studies were negative in 194 patients (71.6%) and positive in 51 patients (27.1%). Seven of the 51 patients (13.7%) had an additional significant injury at operation that was not seen on the CT scan. Nineteen patients had a negative CT scan, a positive DPL, and a significant injury confirmed at celiotomy. In this group of 19 patients, the CT failed to identify seven splenic, three hepatic, and three small bowel injuries. There were two complications attributed to DPL. Three patients had a false negative DPL. Diagnostic peritoneal lavage continues to be a reliable study (sensitivity--95.9%, specificity--99%, accuracy--98.2%). The CT scan is not as sensitive (sensitivity--74.3%, p less than 0.001; specificity--99.5%, accuracy--92.6%). It is concluded that selective use of both procedures is appropriate as long as one recognizes the inherent limitations of each.

Intra-arterial digital subtraction angiography in the evaluation of peripheral vascular trauma.

The role of intra-arterial digital subtraction angiography (IADSA) in the evaluation of extremity trauma has not been clearly established. Several potential advantages would make IADSA a preferable study to conventional angiography (CA). This retrospective study analyzed 104 major peripheral arteries with suspected injury. Multiplane IADSA studies were compared with conventional angiography of the same vessel in 97 patients. The arteriograms were evaluated by a physician and a radiologist in a double-blinded fashion. IADSA correlated well with CA. Similar findings comparing both studies were noted in 101 of 104 angiograms (97%) (p less than 0.001) in review by the radiologist and in 100 of 104 (96%) (p less than 0.001) by the surgeon. Only one injury confirmed at surgery was not seen on IADSA; this study was read as equivocal by both examiners. These data confirm that IADSA is a reliable and reasonable study for the evaluation of patients with suspected peripheral arterial injury.

Pseudo renal artery stenosis (PRAS) syndrome.

During the course of a long-term, prospective, randomized study in 77 hypertensive nephrosclerosis patients, five patients developed evidence suggestive of renal artery stenosis. However, arteriography demonstrated patent renal arteries. The evidence suggestive of renal artery stenosis was: (1) converting-enzyme inhibitor (CEI)-induced renal dysfunction including marked and reversible increases in serum creatinine and urea concentrations, (2) minoxidil-induced hyperreninemia despite beta-adrenoceptor blockade and volume expansion, and (3) minoxidil-induced salt and water retention with diuretic resistant edema. Thus, the renal dysfunction induced by CEI in these patients with patent renal arteries is similar to the alterations occurring in patients having bilateral renal artery stenosis. The diuretic resistant edema and the beta-adrenoceptor blocker resistant high renin release are also functional alterations of renal artery stenosis. We suspect that the long-standing and usually severe hypertension in these patients has caused sufficient arteriolar hypertrophy or sclerosis to interfere with renal blood flow and to induce these functional lesions of renal artery stenosis. With widespread use of the new CEI agents in patients with renal disease, this syndrome suggestive of renal artery stenosis may be encountered in as many as 10% of hypertensive nephrosclerosis patients during long-term treatment with converting-enzyme inhibitors.