The role of a new noninvasive imaging technology in the diagnosis of anemia. (57/1139)

Traditionally, numerical data regarding the status of a patient are a combination of measurements made at the point of care (POC) and those made in the laboratory on specimens withdrawn from the patient. We report here on our experiences with a new method for a noninvasive determination of anemia, as defined by blood hemoglobin (Hb) concentration. This method is based on a novel technology, orthogonal polarization spectral imaging, which provides high quality digitized images of the microcirculation using reflected light. Measurements of Hb, based on the analysis of these images at the POC, were found to compare favorably with results obtained with traditional laboratory methods. Additional advantages of these new POC technologies are that they will make possible completely new measurements that may have no direct analog with existing methods. For example, orthogonal polarization spectral imaging can give feedback regarding microvascular density, which also may be reduced in anemic subjects. This information may give earlier and different insights regarding the patient status in nutritional deficiency anemia than an Hb concentration only. However, additional research will be required to confirm the accuracy and utility of this measurement, especially in adult and pediatric populations, where anemia is more commonly encountered. The ultimate success of POC testing will require collaboration between the attending health care professional, the laboratory and institutional management to rapidly assimilate improved methodologies and new information to provide benefits to the patient.  (+info)

Setting standards for pathology service support to emergency services. (58/1139)

Quality standards have been established in two key areas of pathology directly relevant to standards for the provision of emergency medical services. First, there is a national scheme for accreditation of laboratory services--Clinical Pathology Accreditation (UK) Ltd (CPA)--which has been in formal operation since 1992 and currently covers about 80% of all UK laboratories. Secondly, guidelines have been issued by the Joint Working Group on Quality Assurance (JWGQA) on the support to any point-of-care (near patient) testing facilities. Point-of-care testing (POCT) is increasingly popular in emergency areas, where the availability of faster test results is expected to expedite diagnosis and treatment. When laboratory services are not accredited or POCT equipment and its usage are outside laboratory supervision, there should be concerns that quality standards for pathology service support of the emergency services are not being met.  (+info)

The Southwestern Ontario Joint Replacement Pilot Project: electronic point-of-care data collection. Southwestern Ontario Study Group. (59/1139)

OBJECTIVE: To pilot a provincial joint replacement registry using electronic point-of-care data collection. DESIGN: Data collection study. SETTING: Southwestern Ontario, which has a population base of 3.5 million people. PARTICIPANTS: Eighteen orthopedic surgeons. METHOD: Information on total hip and knee replacements was obtained by the orthopedic surgeons over a 6-month period. Information was obtained in paper form and electronically on hand-held computers. MAIN OUTCOME MEASURES: Patient demographics, waiting times from referral to operation, patient satisfaction and relevance and value of electronic records compared with paper records. MAIN RESULTS: Data were collected on 815 total hip and knee arthroplasties. A slightly greater number of hips required revision than knees. The majority of patients were in the 60 to 90-year age range. With respect to the waiting time from referral to operation 10% of patients waited less than 5 weeks, 50% waited less than 30 weeks, and 90% waited less than 59 weeks. There was a high level of patient satisfaction with the operation and with hospital care received. Most surgeons found that the gathering and use of data electronically was relevant and easy. The electronic data were more timely, accurate and complete than paper records. CONCLUSION: Electronic point-of-care data collection is appropriate, particularly in high-volume, high-cost surgical interventions such as total joint replacements.  (+info)

Physician-performed point-of-care echocardiography using a laptop platform compared with physical examination in the cardiovascular patient. (60/1139)

OBJECTIVES: The purpose of this study was to compare the results of physical examinations (PEs) performed by board-certified cardiologists with the results of point-of-care (POC) echocardiography in a group of patients with cardiovascular disease. BACKGROUND: Although cardiovascular PE is crucial in the evaluation of patients with suspected heart disease, the skills required to diagnose abnormal cardiovascular findings have been declining. Echocardiography is a powerful noninvasive cardiovascular diagnostic tool; however, echocardiographic evaluation of patients is not performed at the time of patient encounter (POC echocardiography), beacuse current platforms are cumbersome and expensive for individual physician use. The development of miniaturized echocardiographic equipment has the potential to overcome some of these limitations. METHODS: Thirty-six subjects had a complete cardiovascular examination by four board-certified cardiologists. The physicians subsequently imaged each patient using a miniaturized echocardiographic platform. The yield of PE and POC echocardiography were compared using a complete echocardiographic study as the gold standard, performed on an upper-end platform. RESULTS: Cardiac examination failed to detect 59% of the overall cardiovascular findings. Physician-performed echocardiography with the prototype device missed 29% of the overall cardiovascular pathology. When considering only the major cardiovascular findings, the cardiologists' PEs still failed to correctly detect 43%. Point-of-care echocardiography reduced this to 21% without significant interphysician variation. CONCLUSIONS: Point-of-care echocardiography using a miniaturized echocardiographic platform substantially improved the detection of important cardiovascular pathology compared with PE. Use of this device by a cardiovascular specialist with training in echocardiography as a routine adjunct to PE appears to be useful.  (+info)

How useful is hand-carried bedside echocardiography in critically ill patients? (61/1139)

OBJECTIVES: The study compared a hand-carried echocardiography (HC) device with standard echocardiography (SE) in critically ill patients. BACKGROUND: Recently, small HC devices have been introduced, and early reports showed a good correlation with SE. METHODS: We used HC (SonoSite, Bothell, Washington) echocardiography to evaluate critically ill patients, and we compared the results with SE obtained with state-of-the-art equipment (Sonos 5500, Hewlett-Packard, Andover, Massachusetts). Each of 80 critically ill patients was studied twice (HC and SE). The studies were done and interpreted separately in blinded fashion. RESULTS: The HC device missed a clinical finding related to the reason for referral in 31% of patients. In 19% of patients a clinically important finding separate from the indication for echocardiography was also missed. The total number of patients with one or more missed findings was 36 (45%). Findings were missed by HC for several reasons. First, HC does not contain spectral Doppler, electrocardiographic, or M-mode capabilities. Two-dimensional imaging is superior on SE, with improved image processing. In addition, although HC does contain color power Doppler, it does not have true color flow Doppler imaging. Therefore, HC often failed to detect or accurately quantify valvular regurgitation. CONCLUSIONS: Although the HC device was able to provide important anatomic information, the device falls far short of SE in the evaluation of critically ill patients.  (+info)

Bedside vena cava filter placement guided with intravascular ultrasound. (62/1139)

OBJECTIVE: The purpose of this study was to report a feasibility trial approved by the Institutional Review Board for insertion of inferior vena cava (IVC) filters with intravascular ultrasound (IVUS) guidance in the intensive care unit. METHODS: Between October 1998 and May 2000, 26 patients (15 men, 11 women; age range, 22-86 years; mean, 55 years) were enrolled. Eight patients (31%) underwent prophylactic filter placement, and 18 patients (69%) had venous thromboembolism (deep venous thrombosis = 16, pulmonary embolism = 2) with contraindications to anticoagulation. A single groin puncture was used for IVUS and filter placement. Location of major branch veins, thrombosis, and caval diameter were readily demonstrated without the use of radiocontrast agents. Mapping of the IVC permitted assessment of ideal filter location. Postprocedure radiographs (23 of 26) were obtained to document filter position. Seventeen of 26 had follow-up lower extremity duplex studies. RESULTS: Twenty-four (92%) of 26 patients underwent successful filter deployment. The two other patients had filters subsequently placed by means of traditional fluoroscopic techniques. One femoral vein insertion site thrombosis resolved after a month. One patient experienced symptomatic caval thrombosis thought to be caused by thrombus trapping 55 days after the procedure. No pulmonary emboli occurred after filter placement. One patient's death was unrelated to vena cava filter placement. The hospital charge for bedside filters was $3623 compared with $4165 (P =.281) for fluoroscopic placement. CONCLUSION: Bedside insertion of an IVC filter with IVUS guidance is feasible and may be an effective alternative in the intensive care unit. No additional costs were incurred in this small series. Protocol refinements should reduce the incidence of complications. The results of this study support the need for further evaluation comparing it with standard techniques.  (+info)

The adenosine triphosphate test: a bedside diagnostic tool for identifying the mechanism of supraventricular tachycardia in patients with palpitations. (63/1139)

OBJECTIVES: This study assesses the value of the "ATP test" (injection of adenosine triphosphate [ATP] during sinus rhythm) for identifying patients with palpitations of unclear etiology who actually have atrioventricular (AV) nodal re-entry tachycardia (AVNRT) or AV re-entry tachycardia (AVRT). BACKGROUND: Because AVNRT and AVRT can be cured with radiofrequency ablation, documentation of spontaneous AVNRT or AVRT usually prompts referral for electrophysiologic (EP) evaluation. However, these paroxysmal arrhythmias may elude clinical diagnosis. We recently showed that administration of ATP during sinus rhythm often reveals dual AV node physiology or a concealed accessory pathway (AP) in patients with documented AVNRT or AVRT. Thus, we postulated that the ATP test could identify patients with palpitations who actually have AVNRT or AVRT and would therefore benefit from EP evaluation. METHODS: One hundred forty-six patients (54 with "palpitations without documented arrhythmias" and 92 with "documentation of arrhythmias of unclear mechanism") underwent a noninvasive ATP test. ATP was injected during sinus rhythm using 10 mg increments. The ATP test was considered positive when prospectively defined signs of dual AV node physiology or concealed AP were disclosed in the electrocardiogram. These findings were correlated with the results of EP evaluation. RESULTS: A positive ATP test predicted induction of AVNRT or AVRT with a positive predictive value of 93% (sensitivity 71%) but a negative predictive value of 37% (specificity 76%). CONCLUSIONS: A bedside ATP test identifies patients with palpitations who are likely to have AVNRT or AVRT (and who are therefore likely to benefit from EP evaluation) with a high positive predictive value.  (+info)

Bedside leukoreduction of cellular blood components in preventing cytomegalovirus transmission in allogeneic bone marrow transplant recipients: a retrospective study. (64/1139)

BACKGROUND AND OBJECTIVES: Cytomegalovirus (CMV) infection continues to be a major complication of bone marrow transplants (BMTs). Administration of leukoreduced unscreened cellular blood products at the bedside has been shown to be effective in preventing CMV transmission via transfusions in CMV-seronegative bone marrow transplant recipients who receive their transplants from CMV-seronegative donors. The aim of this study was to determine whether CMV infection occurred in CMV-seronegative BMT patients who received CMV-seronegative donor marrows and CMV untested blood products leukodepleted at the bedside. DESIGN AND METHODS: We collected data over a 2-year period from patients undergoing allogeneic transplantation who received leukoreduced cellular blood components that were not screened for CMV. All CMV-seropositive patients and donors were excluded from the study. The CMV status of both the donors and the patients was determined before the transplantations. CMV cultures of urine, blood buffy coat, bone marrow samples and bronchial washings were performed if necessary in patients. RESULTS: Thirty-six CMV-seronegative patient-donor pairs were included in the study. Five patients (13.89%) were serologically reactive, but their CMV cultures were negative and they did not show signs or symptoms of CMV infection. These patients received intravenous immunoglobulin and thus could have acquired anti-CMV passively. INTERPRETATION AND CONCLUSIONS: The confidence interval in this study is 0/36 incidence of CMV infection. Our present findings support those of prior studies showing the effectiveness of filtered unscreened blood components as an alternative transfusion support for CMV-seronegative marrow transplant recipients. Studies in larger number of patients are warranted.  (+info)