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Biomedical subjects

F A Mann

Publications and source records attributed to F A Mann.

At least 73 records · Page 4Linked to original sources
PubMed1994

Computer-based videotape analysis of trauma resuscitations for quality assurance and clinical research.

PURPOSE: To automate time (and motion) studies of major trauma resuscitations. TECHNIQUES: We modified an existing time-motion study technique based on time-encoded videotaping for medical imaging workstation human factors analysis. Videotapes were recorded of the trauma room during normal clinical activity using an unobtrusive mounted camera. The videotapes are displayed through a customized interface using a Macintosh-based display system. Within this platform, the time-motion study module allows flexible task definition, multiple concordant task assignment, and various summary result presentations. We established an expert panel of two traumatologists, two emergency radiologists, and two time-motion study experts. The expert panel prospectively and uniquely defined important recognizable procedural and cognitive tasks and personnel (MD, RN, EMT, RT, etc.) involved in trauma resuscitation based on pilot recordings and collective experience. These task functions were used to define a menu in the time-motion analysis software. During retrospective videotape review, the beginning and ending times of each task performed were recorded by electronically highlighting each defined individual and task. The summary results can be displayed in list, tabular, or graphic form by individuals, personnel classifications, or tasks.

Clinical Protocols↗
PubMed1994

Wrist instability series: increased yield with clinical-radiologic screening criteria.

PURPOSE: To develop screening criteria for patients with wrist pain who have carpal instability. MATERIALS AND METHODS: Data were accumulated retrospectively from the cases of 535 patients with painful wrists (321 male and 214 female patients, aged 11-71 years), who underwent wrist arthrography and wrist instability series between 1979 and 1990. Four screening criteria were evaluated: abnormal carpal alignment on routine radiographs, scapholunate joint or ligament pain, reproducible painful clicking or popping, and positive capitolunate instability pattern. Patients with one or more criteria were assigned to group 1. Patients without any of the criteria were assigned to group 2. RESULTS: Group 1 comprised 142 patients (27%) and group 2 comprised 393 patients (73%). In group 1, 69 (49%) patients had abnormal wrist instability findings, and in group 2, nine (2%) had such findings. All abnormalities in group 2 were depicted on routine arthrograms. CONCLUSION: With use of these screening criteria, the majority of patients with wrist pain do not need to undergo wrist instability series and those that do can undergo a specially tailored series.

Adolescent↗
PubMed1994

Evaluation of the injured cervical spine: comparison of conventional and storage phosphor radiography with a hybrid cassette.

PURPOSE: To compare conventional and storage phosphor radiography of the injured cervical spine. MATERIALS AND METHODS: Sixty-five patients underwent imaging in a supine position while wearing a cervical collar. Matched storage phosphor and conventional lateral cervical spine radiographs were obtained with an 18 x 24-cm hybrid cassette. Edge-enhanced and nonenhanced copies of each computed radiograph were printed on film, and the images were sent via a computer network to a remote imaging workstation. Four radiologists read the conventional radiographs, the two hard-copy computed radiographs, and the soft-copy images and used a binary scale to score the visibility of bone and soft-tissue structures. RESULTS: All readers scored better in all areas with computed radiographs, and a statistically significant (P = .030) improvement in performance was seen for soft-tissue structures. CONCLUSION: Storage phosphor imaging offers advantages over conventional radiography, and digital images may be a viable alternative to film.

Cervical Vertebrae↗
PubMed1994

A force plate and display system for studying ground reaction forces in dogs.

We have developed and implemented a low cost system for measuring ground reaction forces in dogs with normal and abnormal ambulation as they walk or trot over a floor mounted plate that measures vertical and horizontal forces. Orthogonally mounted strain gages measure the forces imposed. A bridge amplifier conditions the signals which are sampled and converted to digital form for display on an operator initiated graphical user interface (GUI) which displays the forces as a function of time on the screen of a Macintosh computer. The system also allows the input of timing of the velocity of approach to the plate and the foot strike can be monitored (via tap reply) on the computer screen to verify the fidelity of the foot strike on the active surface of the plate. The data gathered on a particular strike is stored as a "raw" signal, analyzed and recorded in a spread sheet text format for later analysis.

Analog-Digital Conversion↗
PubMed1993

Use of ultrasonography and secondary wound closure to facilitate diagnosis and treatment of a cranial mediastinal abscess in a dog.

A 3-year-old dog was examined because of acute, severe respiratory distress. Harsh inspiratory sounds, oral abrasions, and pyrexia were identified. On thoracic and cervical radiographs, the trachea appeared to be ventrally displaced and narrowed for several centimeters of its length at the thoracic inlet. Cytologic examination of a transcutaneous aspirate from the caudal cervical region revealed a neutrophilic exudate with extracellular bacteria. The ultrasonographic appearance of the thoracic inlet lent support to a diagnosis of cranial mediastinal abscess. Drainage and debridement of the abscess was accomplished via a ventral midline cervical approach, and the site was managed as an open wound. After 6 days, secondary wound closure was performed. The ventral cervical approach prevented contamination of the pleural space, and treatment as an open wound allowed inspection of the affected tissues to determine optimal time for wound closure. The cause of this cranial mediastinal abscess was unknown.

Abscess↗
PubMed1993

Evaluation of a one-step surgical preparation technique in dogs.

The efficacy of a 1-step surgical preparation technique for skin of dogs prior to elective ovariohysterectomy was evaluated. Dogs randomly assigned to group 1 (n = 30) had their skin prepared for surgery by use of a 2-step method, whereas the skin of dogs in group 2 (n = 30) was prepared for surgery by use of a commercially available product for a 1-step technique. Culture plates for quantitative bacterial counts were applied to the proposed incision site on dogs under general anesthesia after hair at the site was clipped and vacuumed but before antiseptic was applied. A second quantitative bacterial culture plate was applied to the proposed incision site after completion of the surgical preparation technique. Surgeries were routinely completed, and dogs were evaluated by physical examination the next day and at the time of suture removal (7 to 10 days after surgery) for complications. Postoperative complications were minor and consisted primarily of subcutaneous swelling, which resolved with time. All cultures obtained prior to skin preparation included bacteria or yeast. Sixteen cultures obtained after skin preparation (group 1, n = 11; group 2, n = 5) included bacteria or yeast. The total number of colonies of potential pathogens (Staphylococcus sp and Enterobacteriaceae) on the preparation cultures was 9,339; 4 colonies were counted on the postpreparation cultures. Potential bacterial pathogens, ie Streptococcus intermedius and gram-negative bacteria, were isolated from dogs prepared with the 2-step technique.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

The influence of age and gender on radial height.

Radial height was measured on carefully standardized posteroanterior x-ray films of the wrist in 25 male and 25 female patients. The range of radial height (10 to 18 mm) was the same for both male and female patients, with slightly different means for each sex. In females the mean was at the upper limit of the previously reported range, whereas in males the mean was outside the reported range. Our results suggest that previously published measurements underestimate radial height. Inasmuch as radial height may be used in planning management of distal radial fractures, it is important to redefine these measurements. We also believe that the wide range of normal makes comparison with a noninjured contralateral wrist essential for accurate assessment of radial shortening in each individual patient.

Adolescent↗
PubMed1993

The night stalker effect: quality improvements with a dedicated night-call rotation.

RATIONALE AND OBJECTIVES: The authors assessed whether a non-sleep-deprived, second-year diagnostic radiology resident assigned to an after-hours "night stalker" emergency radiology (ER) rotation in an urban university hospital has a measurable impact on the number and clinical significance of "missed" radiologic findings. METHODS: After-hours Emergency Department (ED) radiographs interpreted by radiology residents between January and December 1991 were reviewed daily by ER faculty. Faculty-modified final interpretations were recorded on a worksheet and given to the attending ED physician (EDP). The EDP reviewed and, if indicated, modified clinical dispositions, and categorized missed diagnoses as requiring recall into the following categories: 1 = immediately, 2 = in 24 to 48 hours, 3 = no recall necessary, or 4 = recognized during patient visit by clinicians. Morbidity attributable to "misses" was graded A to C (A, definite; B, possible; C, none). All cases requiring patient recall were evaluated monthly with follow-up information and classified as false-positive, false-negative, or indeterminant. The relative performance of control (traditional "call") and night stalker groups were compared. RESULTS: Of 26,421 on-call examinations in 1991, there were 489 (1.1%) misses, of which 202 (1.4%) were from the June-to-December study group. The control group residents averaged 2.75 hours of sleep per call night. On night stalker days, on-call residents and the night stalker averaged 5.75 and 7.25 hours of sleep daily, respectively. The fractions (and number) of recall assignments of discordant cases for the control and night stalker groups, respectively, were: 1) immediate 48% (23) and 26% (32); 2) within 48 hours 31% (15) and 26% (31); 3) no recall 79% (38) and 36% (43); and, 4) abnormality not missed by EDPs 10% (5) and 12% (15). Morbidity for the control and night stalker groups, respectively, were: 1) 4% and 0%; 2) 31% and 30%; and 3) 65% and 70%. The amount of rework between July and December 1991 spent by the EDPs to re-evaluate cases because of discordant opinions was more than 68 hours, with no significant difference noted between the study groups. Errors were false-negative, 84.9% (415); false-positive, 7% (34); and indeterminant, 8.2% (40). Radiology faculty errors contributed 5.8% (13) of patient recalls (false-positive, 11; false-negative, 2). Finally, 58/78 questionnaire respondents believed that service quality had improved. No one believed that the standard of service had been lowered. CONCLUSIONS: A dedicated night-shift ER coverage of a busy urban ED improves quality, appropriateness, and timeliness of patient care.

Diagnostic Errors↗
PubMed1993

Two polymorphic microsatellites in a coding segment of the canine androgen receptor gene.

A 0.6-kb segment of exon 1 of the canine androgen receptor gene contains two polymorphic CAG tandem repeats which encode strings of glutamine homopolymers. The number of CAGs in each tandem repeat was determined by (1) polymerase chain reaction (PCR) amplification of a gene segment containing both repeats, (2) cleavage between repeats with restriction enzyme EcoO109I and (3) fractionation of the restriction fragments containing individual CAG repeats by denaturing polyacrylamide gel electrophoresis (PAGE). Individual genomic DNA samples from 80 unrelated dogs (53 males plus 27 females for a total of 107 X chromosomes) contained 10-12 CAGs in the 5' repeats and 10-13 CAGs in the 3' repeats. Thirteen distinct androgen receptor genotypes were identified. Eleven (or 41%) of the 27 unrelated females were heterozygous in one or both repeat regions, whereas all male samples produced single bands as expected for X chromosome markers. A total of seven distinct haplotypes contributed to the 13 genotypes. The 'polymorphism information content' or 'PIC' for this seven-allele X chromosome marker was 0.67.

Amino Acid Sequence↗
PubMed1993

Three-compartment wrist arthrography: correlation of pain site with location of uni- and bidirectional communications.

OBJECTIVE: Our objective was twofold: (1) to determine whether the site of patients' pain correlates with abnormal findings on three-compartment wrist arthrograms and (2) to determine whether the directional nature (uni- vs bidirectional) of communication(s) between adjacent wrist joint compartments shown on three-compartment wrist arthrograms correlates with the presence and site of pain. MATERIALS AND METHODS: We retrospectively studied 462 three-compartment wrist arthrograms of 458 patients. The patients were divided into four groups according to the site of pain, the correlation of that site with the site of the communication, and the directional characteristics of communications shown on the arthrogram: (1) exact correlation between site of pain and arthrographic findings, (2) correlation only between side of pain (ulnar or radial) and arthrographic findings, (3) ambiguous correlations (e.g., multifocal, midline, or diffuse pain), and (4) no correlation between site of pain and arthrographic findings. RESULTS: In 191 patients (42%), 226 intercompartmental communications were detected (51 uni- or 173 bidirectional). One hundred sixty-one patients had only one communication (uni- or bidirectional), and 30 patients had more than one (uni- and/or bidirectional) communication for a total of 65 defects. Regardless of the directional nature of the communication, no positive association between sites and/or the side of symptoms and sites of communications was demonstrable. However, a potential association appears to exist between ulnar-sided pain and combined lunotriquetral and triangular fibrocartilage tears. CONCLUSION: Our results suggest that the directional nature of interjoint communications has little or no clinical significance. Thus, with the exception of seeking the cause of ulnar-sided pain, our results question the usefulness of routine arthrography for correlating sites of patients' symptoms and individual interjoint communications.

Adolescent↗
PubMed1993

Lack of correlation between site of wrist pain and location of noncommunicating defects shown by three-compartment wrist arthrography.

OBJECTIVE: Communicating defects shown by wrist arthrography often correlate poorly with the location of the patient's symptom(s). No study of wrist arthrography in which noncommunicating defects have been isolated, described, and correlated with the site of patients' symptoms has been reported. The aim of this study was to correlate the site(s) of patients' pain and the location(s) of noncommunicating defects shown by wrist arthrography. MATERIALS AND METHODS: One hundred noncommunicating capsular defects and incomplete defects of the interosseous ligaments and triangular fibrocartilage in 82 patients were identified from 462 three-compartment wrist arthrograms. Correlation between the sites of pain and sites of the noncommunicating defect was described as: (1) exact correlation, (2) ulnar/radial side correlation, (3) ambiguous correlation, or (4) no correlation. Statistical analysis was performed for each type of defect separately, in aggregate for patients who had more than one defect, and by separate analysis using patients' age (less than or greater than 30 years old). RESULTS: Capsular defects were detected in 65 patients, incomplete perforations of the triangular fibrocartilage in 28 patients, and incomplete defects of the scapholunate and lunotriquetral ligament in three patients each. No statistically significant correlation was found between individual defects and symptoms or between the site(s) of symptoms and patterns of multiple noncommunicating defects. Further, age did not influence the degree of correlations (chi 2 = 0.000-0.476, p values = 0.49-1.00). CONCLUSION: Attribution of patient's symptoms to noncommunicating defects shown by wrist arthrography is not reliable. Cases in which site-specific arthrographic defects directly correlate may be fortuitous. Additional studies will be necessary to determine the future role of wrist arthrography in the evaluation of the painful wrist.

Adult↗
PubMed1993

Quality assessment in radiology: value of a portable bar-code scanner integrated with a computer workstation.

Radiographs are typically processed by several employees of a radiology department before being interpreted by a radiologist. A technologist acquires and labels the radiograph(s), and file room employees match the radiograph(s) with prior examinations and prepare them for interpretation by the radiologist. Every radiologist has encountered radiologic examinations in which the image quality, presentation, or associated clinical or technical information is suboptimal. In small departments, the process of immediately tracking the problem to its source and correcting it might be straightforward, albeit an annoying interruption to the radiologist's focus on clinical care. However, in larger departments, trends of human error or machine malfunction may be overlooked or untraceable because no effective method exists to track the quality of images and associated information. A feedback loop from radiologists to the department's ancillary personnel can result in a cycle of continuous quality improvement that enhances the quality of radiographic examinations and also decreases waste. To achieve this, we designed and implemented a computerized process that involves a portable bar-code scanner, a personal computer workstation, and our existing radiology information system.

Electronic Data Processing↗
PubMed1993

Quality assurance: a system that integrates a digital dictation system with a computer data base.

One of the most challenging responsibilities for radiologists is assessment of the quality of care that they provide. Some parameters of quality, such as false-negative rate, are almost impossible to calculate with absolute precision. The issue is also complicated when one tries to determine exactly what constitutes a "discordant" interpretation. However, even when a radiologist discovers that a radiographic finding was missed, or that an inappropriate examination was done, the steps necessary to perform an analysis of the problem can be very disruptive to one's clinical focus at the moment. This suggests that a major obstacle to participation in quality assurance by radiologists is the lack of an adequate infrastructure. We have integrated our digital dictation system with a personal computer data base for tracking cases appropriate for quality assurance, thus allowing radiologists to log any examination from any dictation station in our department with minimal interruption to their clinical activities. Quality assurance and peer review are facilitated by using a personal computer for otherwise tedious aspects of information management. Radiology departments that have a convenient, department-wide method for entering cases--such as a digital dictation system--are ideal for this technique.

Humans↗
PubMed1993

Effects of intra-articular chlorhexidine diacetate lavage on the stifle in healthy dogs.

Eight dogs were determined to be orthopedically normal on the basis of prelavage physical examination, stifle radiography, synovial fluid analysis, and force plate analysis (peak vertical force normalized for body weight, and time on the force plate). Each dog had 1 stifle randomly assigned to be lavaged with 100 ml of a commercially available 0.05% (w/v) chlorhexidine diacetate solution, and the contralateral stifle was lavaged with lactated Ringer's solution. Difference was not detected between the chlorhexidine diacetate and lactated Ringer's solution-treated joints, with regard to results of synovial fluid analysis and clinical lameness evaluations on days 4 and 8 after lavage. Chlorhexidine diacetate caused a more intense synovitis than did lactated Ringer's solution, as determined by histologic evaluation of synovial membrane specimens after necropsy on day 8; however, a difference in the intensity of toluidine blue staining of articular cartilage was not found between treatments. Chlorhexidine diacetate, as a 0.05% (w/v) solution, cannot be recommended as a joint lavage fluid until the duration of inflammatory changes in the synovial membrane are determined or until the chemical constituents of chlorhexidine diacetate causing the synovitis can be identified and removed.

Animals↗
PubMed1993

Marking margins of tumorectomies and excisional biopsies to facilitate histological assessment of excision completeness.

Assessment of tumor margins for completeness of excision is important for local control of neoplastic masses, particularly those that are potentially curable with surgery. Of the margin-marking techniques available, India inking seems to be the most practical way for veterinary clinicians to help pathologists accurately distinguish between surgical margins and margins created during sample processing. India inking prevents misinterpretation of contaminated processing margins as inadequate surgical excisions; however, a strongly definitive decision that an excision is complete cannot be made with any margin-marking technique because it is impossible to examine the entire surface of every margin.

Animals↗
PubMed1992

Identification of surgical biopsy borders by use of india ink.

Separation of surgical biopsy borders from artifactual borders created during trimming of biopsy specimens is necessary to avoid misinterpretation of histologic borders. Misinterpretation of a contaminated trimming border as a surgical border may lead to additional surgery and excessive removal of normal tissue. Likewise, a neoplasm may regrow locally or metastasize if a surgical border infiltrated with neoplastic cells is falsely assumed to be an artifactual trimming border. The use of India ink for distinguishing between surgical biopsy borders and artifactual borders was evaluated. Ten normal tissue specimens from 8 types of tissue (skin, small intestine, urinary bladder, bone, muscle, lung, large intestine, and uterus) were obtained from freshly euthanatized dogs. The specimens were painted with India ink and examined for adherence of the ink to the cut surface of the specimen. Adherence of the ink was observed in all specimens with the exception of the cut surface of the lung. Twenty-five biopsy specimens from dogs with clinical cases of disease were similarly painted with India ink and evaluated. Twenty-two were identified as neoplastic and 3 as inflammatory lesions. Wedges of tissue were obtained from the center of the biopsy specimens to purposely create borders that contained neoplastic tissue. These positive controls were painted with India ink to evaluate the effect of the ink on the histologic appearance of the neoplastic cells. Distortion or alteration of the cellular architecture was not observed in any of the normal specimens, specimens from dogs with clinical cases, or positive controls. The use of India ink for delineation of biopsy borders is a simple technique that presents few technical difficulties.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗