Association of Internal Medicine Point of Care Ultrasound (POCUS) with Length of Stay, Hospitalization Costs, and Formal Imaging: a Prospective Cohort Study.

Background: Point of care ultrasound (POCUS) use has rapidly expanded among internal medicine (IM) physicians in practice and residency training programs. Many benefits have been established; however, studies demonstrating the impact of POCUS on system metrics are few and mostly limited to the emergency department or intensive care setting. The study objective was to evaluate the impact of inpatient POCUS on patient outcomes and hospitalization metrics. Methods: Prospective cohort study of 12,399 consecutive adult admissions to 22 IM teaching attendings, at a quaternary care teaching hospital (7/1/2011-6/30/2015), with or without POCUS available during a given hospitalization. Multivariable regression and propensity score matching (PSM) analyses compared multiple hospital metric outcomes (costs, length of stay, radiology-based imaging, satisfaction, etc.) between the "POCUS available" vs. "POCUS unavailable" groups as well as the "POCUS available" subgroups of "POCUS used" vs. "POCUS not used". Results: Patients in the "POCUS available" vs. "POCUS unavailable" group had lower mean total and per-day hospital costs ($17,474 vs. $21,803, p<0.001; $2,805.88 vs. $3,557.53, p<0.001), lower total and per-day radiology cost ($705.41 vs. $829.12, p<0.001; $163.11 vs. $198.53, p<0.001), fewer total chest X-rays (1.31 vs. 1.55, p=0.01), but more chest CTs (0.22 vs 0.15; p=0.001). Mean length of stay (LOS) was 5.77 days (95% CI = 5.63, 5.91) in the "POCUS available" group vs. 6.08 95% CI (5.66, 6.51) in the "POCUS unavailable" group (p=0.14). Within the "POCUS available" group, cost analysis with a 4:1 PSM (including LOS as a covariate) compared patients receiving POCUS vs. those that could have but did not, and also showed total and per-day cost savings in the "POCUS used" subgroup ($15,082 vs. 15,746; p<0.001 and $2,685 vs. $2,753; p=0.04). Conclusions: Availability and selected use of POCUS was associated with a meaningful reduction in total hospitalization cost, radiology cost, and chest X-rays for hospitalized patients.

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.

Tablet vs. station-based laptop ultrasound devices increases internal medicine resident point-of-care ultrasound performance: a prospective cohort study.

BACKGROUND: Point-of-care ultrasound (POCUS) is becoming an important part of internal medicine (IM) residency training. Achieving competency requires performing a large volume of clinical exams which can be difficult within the constraints of residency. Often-cited barriers include insufficient resident time and the interruption of daily workflow. Despite availability of hospital station-based laptop ultrasound machines, we hypothesized that the addition of ward team-based tablet ultrasound devices would lower barriers and increase clinical POCUS volume within an IM residency POCUS curriculum at a 670-bed, quaternary care, teaching hospital. IM resident POCUS volumes and characteristics during an 18-mo. baseline (station-based laptop devices only) period were compared to matched months during the intervention (station-based + tablet). RESULTS: Total patients examined with POCUS by 6 inpatient resident teams during the 18-mo. baseline and intervention periods were 1386 and 1853, respectively. Patients examined per month increased during the intervention by 34% (77 vs. 103, p = 0.002). The number of areas (e.g., abdominal, cardiac) and items (e.g., bladder, pericardial effusion) examined per month increased by 27% (p = 0.021) and 23% (p = 0.073), respectively. CONCLUSIONS: A combined program infrastructure of station-based laptop and "in-the-pocket" tablet ultrasound devices lowered common POCUS barriers of inadequate time and workflow disruption for IM residents and resulted in a meaningful increase of exams within a longitudinal residency-based training program where station-based laptop devices already existed.

Point-of-Care Sinus Ultrasound: Impact Within a Large Internal Medicine Clinic and Review of Technique.

Outpatient diagnosis of acute bacterial sinusitis, using only traditional physical examination and clinical criteria, results in the overuse of antibiotics in patients with upper respiratory complaints. Point-of-care maxillary sinus ultrasound is easy to learn and quick to perform in a primary care clinic. The technique can reduce antibiotic prescribing by reassuring both patients and providers of the absence of fluid in the sinus, the hallmark of maxillary sinusitis. A review of the literature, description of technique, and results of sinus ultrasound implementation in a large internal medicine clinic are included.

A Late-Career Internist and Point-of-Care-Ultrasound in a Primary Care Clinic.

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Internal medicine point-of-care ultrasound assessment of left ventricular function correlates with formal echocardiography.

PURPOSE: Although focused cardiac ultrasonographic (FoCUS) examination has been evaluated in emergency departments and intensive care units with good correlation to formal echocardiography, accuracy for the assessment of left ventricular systolic function (LVSF) when performed by internal medicine physicians still needs independent evaluation. METHODS: This prospective observational study in a 640-bed, academic, quaternary care center, included 178 inpatients examined by 10 internal medicine physicians who had completed our internal medicine bedside ultrasound training program. The ability to estimate LVSF with FoCUS as "normal," "mild to moderately decreased," or "severely decreased" was compared with left ventricular ejection fraction (>50%, 31-49%, and <31%, respectively) from formal echocardiography interpreted by a cardiologist. RESULTS: Sensitivity and specificity of FoCUS for any degree of LVSF impairment were 0.91 (95% confidence interval [CI] 0.80, 0.97) and 0.88 (95% CI 0.81, 0.93), respectively. The interrater agreement between internal medicine physician-performed FoCUS and formal echocardiography for any LVSF impairment was "good/substantial" with κ = 0.77 (p < 0.001), 95% CI (0.67, 0.87). Formal echocardiography was classified as "technically limited due to patient factors" in 20% of patients; however, echogenicity was sufficient in 100% of FoCUS exams to classify LVSF. CONCLUSIONS: Internal medicine physicians using FoCUS identify normal versus decreased LVSF with high sensitivity, specificity, and "good/substantial" interrater agreement when compared with formal echocardiography. These results support the role of cardiac FoCUS by properly trained internal medicine physicians for discriminating normal from reduced LVSF.

Case report: an unrecognized etiology of transient gallbladder pain in heart failure diagnosed with internist-performed point-of-care ultrasound.

The excellent sensitivity and specificity of right upper quadrant (RUQ) ultrasound for gallbladder pathology in patients with abdominal pain is heavily relied upon in routine diagnostic evaluation. The hour-to-hour timing of this test in a patient with fluctuating symptoms is not widely recognized as having a significant impact on its sensitivity. However, we present a case report describing the essential role of symptom-timed point-of-care ultrasound in making an elusive diagnosis of transient cholecystalgia in a patient with RUQ pain and congestive heart failure (CHF). This case also demonstrates an important etiology of RUQ pain in patients with CHF beyond that of congestive hepatopathy. A review of the related entities of acalculous cholecystitis, congestive hepatopathy, and diffuse gallbladder wall thickening is provided.

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.

Unfractionated heparin infusion for thromboprophylaxis in highest risk gastric bypass surgery.

BACKGROUND: Patients undergoing gastric bypass for obesity are at risk for postoperative venous thromboembolic complications. Per our routine, these patients receive unfractionated heparin (UFH) per a previously described, blood volume-based, subcutaneous prophylactic UFH protocol. However, some patients have additional risk factors for thromboembolism, and we consider these patients to be at highest risk. To increase the predictability and reliable achievement of prophylactic anti-factor Xa levels for these patients at highest risk, we developed a prophylactic UFH continuous intravenous infusion protocol. METHODS: An UFH prophylactic protocol was developed in which the initial UFH loading dose and infusion rate were determined, based on patient blood volume and age. The target prophylactic anti-factor Xa activity range was 0.15-0.20 units/mL. 19 patients were admitted to the hospital the day before gastric bypass surgery. A prophylactic UFH infusion was initiated, and anti-factor Xa levels were checked and adjusted per protocol. The patients underwent surgery the following day and the UFH infusion was continued intra-operatively. RESULTS: No patients were diagnosed with a deep venous thromboembolism. 2 patients experienced peri-operative hemorrhagic complications in spite of anti-factor Xa activity levels in, or only slightly above, the targeted range. Both patients recovered without further complications. CONCLUSION: For highest risk gastric bypass patients, an UFH prophylactic continuous infusion protocol was effective in preventing postoperative thromboembolic events. Hemorrhagic complications were easily managed and did not result in long-term sequelae.

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.

Heparin resistance as detected with an antifactor Xa assay is not more common in venous thromboembolism than in other thromboembolic conditions.

STUDY OBJECTIVE: To identify whether heparin resistance when measured with an antifactor Xa assay is more frequent in patients with venous thromboembolic disease than in patients with other thromboembolic conditions. DESIGN: Prospective observational cohort study. SETTING: A 625-bed, adults-only, private teaching hospital. PATIENTS: Three hundred seventy-two patients receiving intravenous unfractionated heparin for a variety of indications classified as either venous thromboembolism or arterial thromboembolism. INTERVENTION: All patients received an initial unfractionated heparin dosage according to a protocol based on age and estimated blood volume. Targeted antifactor Xa was 0.35-0.65 U/ml. MEASUREMENTS AND MAIN RESULTS: A modest increase in heparin dosage requirement was noted in patients with venous thromboembolism that was entirely related to lower hemoglobin concentration in that group compared with the arterial thromboembolism group. Low hemoglobin concentration was significantly associated with increased heparin resistance regardless of treatment indication. CONCLUSIONS: True heparin resistance seen with an antifactor Xa assay is not more common in venous thromboembolism than in other conditions. Low hemoglobin concentration, rather than treatment indication, appears to be associated with increased heparin resistance.