Abdo Asmar

Diagnostic accuracy of hospitalist‐performed hand‐carried ultrasound echocardiography after a brief training program

BACKGROUND The duration of training needed for hospitalists to accurately perform hand-carried ultrasound echocardiography (HCUE) is uncertain. OBJECTIVE To determine the diagnostic accuracy of HCUE performed by hospitalists after a 27-hour training program. DESIGN Prospective cohort study. SETTING Large public teaching hospital. PATIENTS A total of 322 inpatients referred for standard echocardiography (SE) between March and May 2007. INTERVENTION Blinded to SE results, attending hospitalist physicians performed HCUE within hours of SE. MEASUREMENTS Diagnostic characteristics of HCUE as a test for 6 cardiac abnormalities assessed by SE: left ventricular (LV) systolic dysfunction; severe mitral regurgitation (MR); moderate or severe left atrium (LA) enlargement; moderate or severe LV hypertrophy; medium or large pericardial effusion; and dilatation of the inferior vena cava (IVC). RESULTS A total of 314 patients underwent both SE and HCUE within a median time of 2.8 hours (25th to 75th percentiles, 1.4 to 5.1 hours). Positive and negative likelihood ratios for HCUE increased and decreased, respectively, the prior odds by 5-fold or more for LV systolic dysfunction, severe MR regurgitation, and moderate or large pericardial effusion. Likelihood ratios changed the prior odds by 2-fold or more for moderate or severe LA enlargement, moderate or severe LV hypertrophy, and IVC dilatation. Indeterminate HCUE results occurred in 2% to 6% of assessments. CONCLUSIONS The diagnostic accuracy of HCUE performed by hospitalists after a brief training program was moderate to excellent for 6 important cardiac abnormalities.

Post-operative serum uric acid and acute kidney injury.

BACKGROUND We hypothesized that post-operative serum uric acid (SUA) may be associated with acute kidney injury (AKI). METHODS In this prospective, observational study, the relationships between SUA, urine neutrophil gelatinase-associated lipocalin (uNGAL) and interleukin-18 (uIL-18), serum monocyte chemoattractant protein-1 (sMCP-1) and tumor necrosis factor-alpha (sTNF-alpha), and incidence of AKI were determined. SUA were divided into tertiles and their association with AKI investigated. RESULTS A total of 100 cardiac surgery patients were included for analyses. The 1st, 2nd, and 3rd SUA tertiles were associated with 15.1%, 11.7%, and 54.5% incidence of AKI, respectively. The 3rd SUA tertile, compared to the referent 1st tertile, was associated with an eightfold (OR 8.38, CI95% 2.13-33.05, p=0.002) increased risk for AKI. Patients with AKI on post-operative day 1 (n=11) were then excluded for the purpose of determining the predictive value of SUA to diagnose AKI on postoperative day 2 and during hospital stay. In comparison to the referent 1st tertile, the 3rd tertile SUA was associated with an eightfold increased risk for AKI on post-operative day 2 (adjusted OR 7.94, CI95% 1.50-42.08, P=.015) and a five-fold increased risk for AKI during hospital stay (OR 4.83, CI95% 1.21-19.20, P=.025), respectively. SUA (Area Under Curve, AUC 0.77 (CI95% 0.66-0.88, P<.001), serum creatinine (0.73, CI95% 0.62-0.84, P<.001) and sTNF-alpha (0.76, CI95% 0.65-0.87, P<.001) had the best diagnostic performance measured by the Receiver Operating Characteristics curves. CONCLUSIONS We conclude that post-operative SUA is associated with an increased risk for AKI and compares well to conventional markers of AKI.

Update on clinical trials for the prevention of acute kidney injury in patients undergoing cardiac surgery.

BACKGROUND Effective therapeutic agents for the prevention and treatment of acute kidney injury (AKI) after cardiac surgery remain elusive despite the tremendous advances in surgical techniques, technology, and understanding of disease processes. Recent developments and their effect on the incidence of AKI after cardiac surgery are discussed. DATA SOURCES Published clinical trials in PubMed, strength of evidence assessed by the guidelines of the American Family Physicians. CONCLUSIONS The definition of AKI has changed, and the focus of interventions has shifted from treatment to prevention to recovery from AKI. Antioxidants and biological agents have been added to classic armaments of hydration and diuretics in addition to tighter metabolic control to prevent AKI. Although the treatment options remain unsatisfactory, a lot of progress nevertheless continues to be made in the prevention and treatment of AKI.

Hand-carried Echocardiography by Hospitalists: A Randomized Trial

BACKGROUND Hospitalists can use hand-carried echocardiography for accurate point-of-care information, but patient outcome data for its application are sparse. METHODS We performed an unblinded, parallel-group randomized trial between July 2008 and March 2009 at one teaching hospital in Chicago, Illinois. We randomly assigned adult general medicine inpatients referred for standard echocardiography with indications investigatable by hand-carried echocardiography to care guided by hand-carried echocardiography or usual care. The main outcome measure was length of stay on the referring hospitalists service. Secondary outcomes included a before-after analysis of reported changes in management due to hand-carried echocardiography and the diagnostic accuracy of hand-carried echocardiography. RESULTS The difference in length of stay between 226 participants randomized to care guided by hand-carried echocardiography (geometric mean 46.1 hours, interquartile range 29.0-70.9 hours) and 227 participants randomized to usual care (46.9 hours, interquartile range 34.1-68.3 hours) corresponded to a 1.7% reduction in length of stay that was not statistically significant (95% confidence interval, -12.1 to 9.8%). In post hoc subgroup analyses, care guided by hand-carried echocardiography reduced length of stay in participants who were referred for heart failure (P=.0008). Among participants who underwent both hand-carried and standard echocardiography, hospitalists changed management due to hand-carried echocardiography in 37%. Despite the favorable diagnostic accuracy of hand-carried echocardiography, most changes to the timing of hospital discharge occurred after standard echocardiography. CONCLUSION Hospitalist care guided by hand-carried echocardiography for unselected general medicine patients does not meaningfully affect length of stay. Whether or not it affects care quality remains unstudied.

A Physiologic-Based Approach to the Treatment of a Patient With Hypokalemia

Hypokalemia is common and can be associated with serious adverse consequences, including paralysis, ileus, cardiac arrhythmias, and death. As a result, the body maintains serum potassium concentration within very narrow limits by tightly regulated feedback and feed-forward systems. Whereas the consequences of symptomatic hypokalemia and severe potassium depletion are well appreciated, chronic mild hypokalemia can accelerate the progression of chronic kidney disease, exacerbate systemic hypertension, and increase mortality. Persistent hypokalemia may reflect total-body potassium depletion or increased renal potassium clearance. In a patient with simple potassium depletion, potassium replacement therapy should correct serum potassium concentration, but may have little effect when renal potassium clearance is abnormally increased from potassium wasting. In such cases, the addition of potassium-sparing diuretics might be helpful. Serum potassium concentration is an inaccurate marker of total-body potassium deficit. Mild hypokalemia may be associated with significant total-body potassium deficits and conversely, total-body potassium stores can be normal in patients with hypokalemia due to redistribution. The speed and extent of potassium replacement should be dictated by the clinical picture and guided by frequent reassessment of serum potassium concentration(.) The goals of therapy should be to correct a potassium deficit, if present, without provoking hyperkalemia. Oral replacement is preferred except when there is no functioning bowel or in the setting of electrocardiogram changes, neurologic symptoms, cardiac ischemia, or digitalis therapy.

Rituximab in immunologic glomerular diseases

Experimental data suggest that the B-cell antigen CD20 may play a significant role in the pathogenesis of many diseases including glomerular diseases. These and other findings underpin the central concept of B-cell-depleting therapies that target CD20 antigen as treatments for lupus nephritis, idiopathic membranous nephropathy, focal segmental glomerulosclerosis, cryglobulinemic glomerulonephritis, antibody mediated renal allograft rejection and recurrent glomerulonephritis in renal allograft. Use of rituximab as a B-cell depleting therapy has been associated with clinical improvement and has emerged as a possible adjunct or alternative treatment option in this field of nephrology.

Application of a utility analysis to evaluate a novel assessment tool for clinically oriented physiology and pharmacology.

Multiple-choice questions are a gold-standard tool in medical school for assessment of knowledge and are the mainstay of licensing examinations. However, multiple-choice questions items can be criticized for lacking the ability to test higher-order learning or integrative thinking across multiple disciplines. Our objective was to develop a novel assessment that would address understanding of pathophysiology and pharmacology, evaluate learning at the levels of application, evaluation and synthesis, and allow students to demonstrate clinical reasoning. The rubric assesses student writeups of clinical case problems. The method is based on the physicians traditional postencounter Subjective, Objective, Assessment and Plan note. Students were required to correctly identify subjective and objective findings in authentic clinical case problems, to ascribe pathophysiological as well as pharmacological mechanisms to these findings, and to justify a list of differential diagnoses. A utility analysis was undertaken to evaluate the new assessment tool by appraising its reliability, validity, feasibility, cost effectiveness, acceptability, and educational impact using a mixed-method approach. The Subjective, Objective, Assessment and Plan assessment tool scored highly in terms of validity and educational impact and had acceptable levels of statistical reliability but was limited in terms of acceptance, feasibility, and cost effectiveness due to high time demands on expert graders and workload concerns from students. We conclude by making suggestions for improving the tool and recommend deployment of the instrument for low-stakes summative assessment or formative assessment.

Anaerobic clavicular osteomyelitis following colonoscopy in a hemodialysis patient

Patients on dialysis are immunocompromised and are therefore susceptible to both common and unusual infectious complications. These infections are often related to their dialysis access but even routine diagnostic tests unrelated to dialysis can also lead to rare adverse events. We present an unusual case of clavicular osteomyelitis from Bacteroides fragilis in a patient on maintenance hemodialysis following colonoscopy. The risk factors for this unusual site of infection, the incidence and guidelines for prophylactic antibiotic administration are discussed here.

Renal cell carcinoma with isolated breast metastasis

Renal cell carcinoma (RCC) is a highly prevalent disease worldwide with many cases being metastasised to various organs during the time of initial presentation. Metastatic RCC to the breast is a rare entity and can mimic primary breast carcinoma. In this article, we present a 63-year-old Caucasian woman presented with a breast mass that was detected by screening mammography and found to have a biopsy proven grade-II clear RCC in the breast tissue. Despite the high incidence and prevalence of primary breast cancer, metastasis from extramammary should be suspected in patients with a prior history of other cancers. In this brief literature review, we also highlight the survival benefit from surgery and close follow-up in selected group of patients with metastatic, metachronous and solitary RCC.

Relationship between classroom attendance and examination performance in a second-year medical pathophysiology class

Studies completed with undergraduate populations have shown that attendance positively correlates with academic performance. A marked decline in classroom attendance within medical school has recently been noticed with the availability of video capture of lectures and other online material. This study compares these in the era of online material. It took place during the second-year Gastrointestinal and Renal Systems module. Attendance was mandatory at team-based learning and case-based learning sessions on new material and voluntary at lectures (29 sessions) and case-based learning on material previously covered (9 sessions). Attendance was recorded prospectively. All lectures were recorded, and all related files were available to students online. Performance was based on a 118 multiple-choice question final examination. Students voluntarily completed the Motivated Strategies for Learning Questionnaire (MSLQ). The study group consisted of 78 students (68% of 114 total) of whom 48 completed the MSLQ. Mean attendance was 24%, with 33% of students attending none of the nonmandatory sessions. The median score on the final exam for participants was 86.0 (range: 28.8). High levels of self-efficacy and the ability to self-regulate effort were predictive of low attendance. Attendance was positively predicted by an orientation toward peer learning and help seeking. There was no correlation between the percentage of classes attended and performance on the final exam. We conclude that different facets of self-regulated learning predict attendance, with highly confident students being the least likely to attend, and that attendance at in-class sessions is no longer a good marker for performance.