In the Literature

The Hospitalist. 2009 October;2009(10):

October 1, 2009 | The Hospitalist

Steven Deitelzweig, MD, MMM, FHM ; Frank Wharton, MD, FACP ; Renee Meadows, MD, FHM ; Srinivas Vuppala, MD ; Kevin Hude, MD ; Doris Lin, MD ; Damodar Kumbala, MD, Department Of

Major limitations of the study were the lack of beta-blockers as an option for rate control and the exclusion of patients with hemodynamic instability, heart failure, and myocardial infarction. As patients with underlying heart disease were excluded, these results cannot be applied to all patients presenting with acute AF.

Bottom line: Compared with digoxin and amidarone, intravenous diltiazem is safe and effective in achieving ventricular rate control to improve symptoms and to reduce length of hospital stay in acute uncomplicated AF.

Citation: Siu CW, Lau CP, Lee WL, Lam KF, Tse HF. Intravenous diltiazem is superior to intravenous amiodarone or digoxin for achieving ventricular rate control in patients with acute uncomplicated atrial fibrillation. Crit Care Med. 2009;37(7):2174-2179.

4) D-dimer Might Be a Reliable Assay to Determine Likelihood of Acute Aortic Dissection

Clinical question: Is the D-dimer assay beneficial in the evaluation of acute aortic dissection (AD)?

Background: Aortic dissection is a potentially lethal disorder that is included in the differential diagnosis of chest pain. No studies exist that specifically examine the use of the D-dimer assay to exclude or predict AD. D-dimer has been proven to be a useful tool to help rule out pulmonary embolism (PE) and DVT.

Study design: Prospective.

Setting: Fourteen centers in the U.S., Europe, and Japan.

Synopsis: Of 220 patients enrolled in the study, 87 had radiologically proven AD, and 133 had an initial suspicion of AD but a different final diagnosis. D-dimer assay was obtained on patients with a suspicion of AD within 24 hours of symptom onset. Additionally, appropriate imaging was performed on all patients to identify AD presence.

D-dimer was found to be a useful “rule out” test. At a cutoff level of 500 ng/mL, the negative likelihood ratio was 0.07 (<0.1 being suggestive of a good rule-out tool) and the negative predictive value was >90%. D-dimer was not shown to be as useful to predict the presence of AD in this study.

A major limitation of the study was a relatively small sample size, especially when subgroups were analyzed, therefore decreasing the overall accuracy of the study. Although this study shows promise for the D-dimer assay in the evaluation of suspected AD, it does not establish D-dimer as a reliable enough test to rule out AD without further imaging or evaluation.

Bottom line: Though this study illustrated a high negative predictive value for D-dimer in AD evaluation, physicians are cautioned against allowing a negative D-dimer to affect their management of a patient with a suspected acute aortic dissection.

Citation: Suzuki T, Distante A, Zizza A, et al. Diagnosis of acute aortic dissection by D-dimer: the International Registry of Acute Aortic Dissection Substudy on Biomarkers (IRAD-bio) experience. Circulation. 2009;119(20):2702-2707.

Clinical Shorts

DUODENAL FEEDING SHOWS IMPROVED OUTCOMES COMPARED WITH GASTRIC FEEDING IN MICU PATIENTS

A prospective randomized clinical study of 121 medical intensive-care unit (MICU) patients revealed that those who received nasoduodenal feeding as opposed to nasogastric feeding achieved nutritional goals earlier and had a lower rate of ventilator-associated pneumonia.

Citation: Hsu CW, Sun SF, Lin SL, et al. Duodenal versus gastric feeding in medical intensive care unit patients: a prospective, randomized, clinical study. Crit Care Med. 2009;37(6):1866-1872.

GRAM’S STAIN OF PERITONEAL FLUID NOT HELPFUL IN DIAGNOSING SPONTANEOUS BACTERIAL PERITONITIS (SBP)

Retrospective chart review shows Gram’s stain of peritoneal fluid has low sensitivity and positive predictive value, and should not alter treatment when SBP has been identified by absolute neutrophil count.

Citation: Chinnock B, Fox C, Hendey GW. Gram’s stain of peritoneal fluid is rarely helpful in the evaluation of the ascites patient. Ann Emerg Med. 2009;54(1):78-82.

IN REFRACTORY CLOSTRIDIUM DIFFICILE INFECTION, INTRAVENOUS TIGECYCLINE MIGHT BE AN ALTERNATIVE TO CONVENTIONAL ANTIBIOTIC THERAPY

Series of case reports shows patients with Clostridium difficile infection, refractory to oral vancomycin and metronidazole, responded well to intravenous tigecycline.

Citation: Herpers BL, Vlaminckx B, Burkhardt O, et al. Intravenous tigecycline as adjunctive or alternative therapy for severe refractory Clostridium difficile infection. Clin Infect Dis. 2009;48(12):1732-1735.

AGE GREATER THAN 65 PREDICTS ABNORMAL PREOPERATIVE EKG

This retrospective review found that besides a history of heart failure, myocardial infarction, angina, severe valvular disease, or high cholesterol, an age greater than 65 is an independent predictor for significant preoperative EKG abnormalities.

Citation: Correll D, Hepner D, Chang C, et al. Perioperative electrocardiograms: patient factors predictive of abnormalities. Anesthesiology. 2009;110(6):1217-1222.