An Ultrasound Screening Exam During Medicare Wellness Visits May Be Beneficial.

OBJECTIVES: The physical exam component of a periodic health visit in the elderly has not been considered useful. Standard Medicare Wellness visits require no physical exam beyond blood pressure and most physicians perform limited exams during these visits. The objective of this study was to test the feasibility, potential benefit, and costs of performing a screening ultrasound (US) exam during Medicare Wellness visits. METHODS: A physician examiner at an academic internal medicine primary care clinic performed a screening US exam targeting important abnormalities of patients 65-85 years old during a Medicare Wellness visit. The primary care physician (PCP) recorded the follow-up items for each abnormality identified by the US examiner and assessed the benefit of each abnormality for the participant. Abnormality benefit, net exam benefit per participant, follow-up items and costs, participant survey results, and exam duration were assessed. RESULTS: Participants numbered 108. Total abnormalities numbered 283 and new diagnoses were 172. Positive benefit scores were assigned to 38.8%, neutral (zero) scores to 59.4%, and negative benefit scores to 1.8% of abnormalities. Net benefit scores per participant were positive in 63.9%, 0 in 34.3%, and negative in 1.8%. Follow-up items were infrequent resulting in 76% of participants without follow-up cost. Participant survey showed excellent acceptance of the exam. CONCLUSIONS: The US screening exam identified frequent abnormalities in Medicare Wellness patients. The assessed benefits were rarely negative and often mild to moderately positive, with important new chronic conditions identified. Follow-up costs were low when the PCPs were also US experts.

Rationale and design of an evidence-based tool to guide preoperative evaluation and management.

BACKGROUND: In the United States, over-testing and over-treatment are recognised causes of excess cost and patient harm. Healthcare value, defined as health outcomes achieved relative to the costs of care, has become a focus to improve the quality and affordability of healthcare. AIM: To describe the rationale for, and development of a standardised clinical preoperative decision-support tool.Program description: An evidence-based, preoperative clinical decision tool was developed to guide preoperative testing and management of high-risk medications.Program evaluation: Patient data before and after implementation of the tool will be analysed to determine its effectiveness in reducing preoperative testing. DISCUSSION: Preoperative testing is an area that presents an opportunity to increase healthcare value and decrease healthcare spending. Guidelines are available to standardise preoperative assessment but their adoption and acceptance into practice has been slow. To systematise preoperative assessment within our healthcare system, we reviewed current published literature and guidelines and synthesised them into an electronic, evidence-based, decision-support tool. After distribution of the tool to clinicians in our healthcare system, we will assess its impact on healthcare value, costs and outcomes. We believe that an evidence-based preoperative tool, seamlessly and efficiently integrated into clinician workflow, can improve preoperative patient care.

Factor X and factor II activity levels do not always agree in warfarin-treated lupus anticoagulant patients.

Warfarin therapy is used in lupus anticoagulant patients with thrombosis and yet the prothrombin time (PT)/international normalized ratio (INR) in these patients can sometimes be falsely elevated. Both a PT-based factor II (FII) assay and a chromogenic, enzymatic factor X (CFX) assay have been used for monitoring when the INR may be artifactual. This study compared FII and CFX assays in lupus anticoagulant-positive and lupus anticoagulant-negative warfarin-treated patients in a cross-sectional study of samples from 21 lupus anticoagulant-positive and 19 lupus anticoagulant-negative outpatients. Plasma samples were simultaneously measured for FII and CFX and the ratio of FII/CFX was used to measure concordance. Compared with lupus anticoagulant-negative patients 14 of the 21 lupus anticoagulant-positive patients had lower FII/CFX ratios (P < 0.01). Three of the patients had ratios less than 0.6 indicating strong disagreement (P < 0.0001). The patient with the lowest FII/CFX ratio had evidence suggesting a specific antibody to FII. Another patient showed that the discordance between FII and CFX varied over time. The CFX assay in the laboratory was technically superior, more precise, and less costly. The CFX assay is preferred for warfarin therapy monitoring in lupus anticoagulant patients when INR artifacts are suspected.

Relationship between chromogenic factor X and international normalized ratio differs during early warfarin initiation compared with chronic warfarin administration.

Chromogenic factor X (CFX) monitoring is necessary in patients with potential international normalized ratio (INR) artifacts during warfarin therapy. The relationship of CFX with the INR needs to be quantitated to have warfarin protocols that are equivalent with either test as a monitoring parameter. This study investigated whether the CFX/INR relationship is different during warfarin initiation compared with that during chronic warfarin therapy. Outpatients (N = 164) taking chronic doses of warfarin and inpatients (N = 137) initiating warfarin therapy had plasma samples tested for CFX and INR. The best fit mathematical relationship of CFX and INR was determined for both groups. A six hundred and twenty-five bed, adult-only, private, tertiary care teaching hospital was the setting of the study. The best fit equation for chronic warfarin patients was quadratic using a reciprocal transformation of the INR. The best fit equation for the warfarin initiation patients was linear using logarithmic transformation of CFX and INR. The predicted CFX from INRs over the range of 1.4-2.2 was 7-18% higher in the warfarin initiation patients than in the chronic warfarin patients. Translation of CFX values into equivalent INRs for use in warfarin initiation and maintenance protocols is improved when using equations specific to the patient situation.

Selecting an equation to estimate glomerular filtration rate for use in renal dosage adjustment of drugs in electronic patient record systems.

STUDY OBJECTIVE: To identify a variant of the Cockcroft-Gault equation whose estimate would agree with the Modification of Diet in Renal Disease (MDRD) estimate of glomerular filtration rate (GFR) since the MDRD equation may not be programmable in some electronic patient record systems. DESIGN: Prospective case series. SETTING: A 625-bed, adults-only, private, tertiary care teaching hospital. PATIENTS: Two hundred eight consecutive hospitalized patients with MDRD-estimated GFRs less than 90 ml/minute/1.73 m 2 . Seventeen patients were black (includes native African immigrants). INTERVENTION: Chemistry assays were performed, and patients' records were reviewed for age, ethnic background, height, and actual weight. Ideal weight, corrected weight, body mass index, body surface area (BSA), and GFR by the original MDRD equation were calculated for each patient. MEASUREMENTS AND MAIN RESULTS: Cockcroft-Gault estimates of renal clearance were calculated by using actual weight, ideal weight, and corrected weight both with and without correction for BSA. These estimates, as well as an estimate of GFR by the abbreviated MDRD equation, were compared with the original MDRD estimate. The results obtained with the abbreviated MDRD equation and with the Cockcroft-Gault equation that used corrected weight and BSA adjustment had the best agreement; both were within +/- 30% of the original MDRD equation in 80% of the 208 patients' results. All other Cockcroft-Gault variants tested were less accurate. CONCLUSION: Electronic patient record databases may not contain a nominal variable database field for black or non-black status, which is required by the MDRD equations. The Cockcroft-Gault equation that used corrected weight and BSA adjustment performed about as well as the abbreviated MDRD equation and can be programmed into electronic patient records. Given the small number of black patients included in this study, further study in this patient population is recommended before applying this Cockcroft-Gault variant to this subgroup.

Unreliability of international normalized ratio for monitoring warfarin therapy in patients with lupus anticoagulant.

STUDY OBJECTIVE: To compare the international normalized ratios (INRs) of patients positive for lupus anticoagulant and the INRs of control patients receiving warfarin therapy with equivalent therapeutic chromogenic factor X levels. DESIGN: Prospective case series. SETTING: A 625-bed, adult, private, tertiary care teaching hospital. PATIENTS: Sixty-eight outpatients positive for lupus anticoagulant and 57 control patients receiving long-term warfarin therapy. MEASUREMENTS AND MAIN RESULTS: Concomitant INR and chromogenic factor X activity were measured in all patients. In 44 control patients (77%) and 46 patients with lupus anticoagulant (68%), chromogenic factor X activity was 22-40% of normal, which is therapeutic. Of the 44 control patients, 4 (9%) had an INR above 3.0, and none had an INR above 4.0. In contrast, 18 (39%) of the 46 patients with lupus anticoagulant had an INR above 3.0, and 5 (11%) had an INR above 4.0. CONCLUSION: At least 10% of patients with lupus anticoagulant receiving long-term warfarin therapy may have falsely high INR values, which could lead to inappropriate warfarin dosage reduction. Monitoring warfarin therapy by chromogenic factor X activity in patients with lupus anticoagulant avoids this INR artifact.

Achieving target antifactor Xa activity with a heparin protocol based on sex, age, height, and weight.

STUDY OBJECTIVES: To develop and validate an improved unfractionated heparin (UFH) dosage protocol, using antifactor Xa levels as the outcome variable. DESIGN: Prospective case series. SETTING: A 625-bed, adults-only private, tertiary care teaching hospital. PATIENTS: Three hundred seventy-two patients receiving UFH for eight different indications were in the protocol derivation group. One hundred ninety-seven patients were in the final validation group. Intervention. Variables that predicted successful UFH treatment were determined by analysis of variance and regression. MEASUREMENTS AND MAIN RESULTS: Sex, age, height, weight, UFH dosage, and antifactor Xa levels were variables. A regression model using sex, age, height, and weight was superior to a weight-only model in predicting UFH dosage. Target-range antifactor Xa levels were achieved with the new protocol in 122 (87%) of 140 patients within 24 hours of start of therapy. CONCLUSION: A UFH dosage protocol based on patient sex, age, height, and weight produced improved initial target antifactor Xa levels compared with a weight-based protocol. The protocol is computerized and easy to apply.

Heparin thromboprophylaxis in gastric bypass surgery.

BACKGROUND: Patients undergoing gastric bypass surgery are at risk for postoperative venous thromboembolism. Thromboprophylaxis often includes fixed doses of some type of heparin. However, it is unlikely that the same dose of subcutaneous heparin will be optimal for all patients, because heparin pharmacokinetics depend on a number of patient variables, including thickness of the adipose layer. METHODS: An adjusted-dose, unfractionated heparin protocol was developed using pharmacokinetic data from 245 medical and surgical patients. Heparin doses were adjusted to achieve subtherapeutic peak anti-factor Xa heparin activity levels of 0.11-0.25 units/mL. This protocol was then applied to a prospective series of 700 patients undergoing laparoscopic Roux-en-Y gastric bypass who had no history of thromboembolism. Heparin prophylaxis was begun the evening of the day of surgery. RESULTS: No patients were diagnosed with a deep venous thrombosis, but 3 (0.4%) were diagnosed with a non-fatal pulmonary embolism. Heparin therapy was halted because of bleeding in 2.3% of patients but only half of these required blood transfusions (1% of total). No patient required reoperation. Minor wound hematomas occurred in 0.6%. There were no deaths from any cause in this series. CONCLUSION: Use of a monitored, adjusted-dose unfractionated heparin prophylactic protocol in a laparoscopic gastric bypass patient population resulted in doses greater than those used in traditional fixed-dose protocols. However, bleeding and thromboembolism rates were very low and no patients died.