2 Minute Medicine Rewind September 14 – September 21, 2014

In this section, we highlight the key high-impact studies, updates, and analyses published in medicine during the past week.

Ultrasonography versus Computed Tomography for Suspected Nephrolithiasis

Thought to have increased sensitivity over ultrasound to detect kidney stones, CT has become the main diagnostic tool for the initial suspicion of nephrolithiasis. A CT scan, however, comes with higher costs and health consequences associated with exposure to radiation as well as the discovery of incidental findings. In this multicenter randomized control trial, 2759 patients were randomized to a CT or an ultrasound, either performed by the emergency physician (point-of-care US) or a radiologist (radiology US). High-risk diagnoses with complications, serious adverse events, pain scores, return emergency department visits, and rates of hospitalizations did not vary significantly between all three groups. Specifically, the rate of serious adverse events and related serious adverse events was 12.4% and 0.3% in the point-of-care US group, 10.8% and 0.4% in the radiology US group, and 11.2% and 0.5% in the CT group (P = 0.50 and P = 0.88), respectively. When calculating cumulative exposure over 6 months, the amount of radiation received was significantly lower in both ultrasound groups when compared to the CT group (P < 0.001). Finally, the sensitivity of detecting kidney stones was in the mid-80s for all three groups (P = 0.74). Thus, given equal detection, complication and hospital admission rates, as well as decreased cost and radiation exposure, ultrasound should be used as the as the primary imaging modality in the detection of kidney stones.

Long-Term Clinical Outcome of Major Adverse Cardiac Events in Survivors of Infectious Endocarditis: A Nationwide Population-Based Study

In the setting of infectious endocarditis (IE), repeated insults by circulating bacteria cause an intense inflammatory response that results in systemic damage. More than one-third of IE patients die within the first year after hospitalization. European guidelines therefore recommend close monitoring of IE patients for major adverse cardiac events (MACE), including stroke, myocardial infarction, and heart failure, for one year after discharge. The long-term consequences and outcomes of IE, however, have been much less studied. In this Taiwanese nationwide cohort study, 10,116 patients who were discharged from the hospital after being admitted for IE (IE survivors) were matched to control subjects without IE to compare the risk of MACE and all-cause death. IE survivors were found to have a higher risk of ischemic stroke (aHR: 1.59, 95% CI: 1.40 to 1.80), hemorrhagic stroke (aHR: 2.37, 95% CI: 1.90 to 2.96), MI (aHR: 1.44, 95% CI: 1.17 to 1.79), readmission for heart failure (aHR: 2.24, 95% CI: 2.05 to 2.43), sudden cardiac death or ventricular arrhythmia (aHR: 1.69, 95% CI: 1.44 to 1.98) and all-cause death (aHR: 2.27, 95% CI: 2.14 to 2.40). Given the substantially increased risk of MACE in IE survivors, continued long-term surveillance of MACE should be considered.

School-age Outcomes of Very Preterm Infants After Antenatal Treatment With Magnesium Sulfate vs Placebo

Despite increased survival rates in infants born at a gestational age less than 28 weeks, the rates of adverse long-term neurodevelopmental outcomes in these infants remain high. Used mainly for eclampsia prevention, magnesium sulfate has also been shown to have a possible neuroprotective effect. Studies have looked at this effect in early childhood, where it has been shown to reduce the prevalence of cerebral palsy and substantial motor dysfunction, but its effect on older school-aged children remains unknown. In this Australian multicenter randomized controlled trial, 1255 pregnant women in whom birth was planned before 30 weeks’ gestation were randomized to magnesium sulfate or placebo. Six to eleven years later, the rates of cerebral palsy were 7.8% and 6.7% (OR: 1.26, 95% CI: 0.84-1.91; P  =  0.27) and that of abnormal motor function were 26.9% and 26.6% (OR: 1.16, 95% CI: 0.88-1.52; P  =  0.28) in the children from the women in the magnesium sulfate and placebo groups, respectively, neither of which were shown to be statistically significantly different. Cognitive, behavioral, growth, and functional outcomes also showed no difference. Longer studies are needed at this time to better understand the long-term neurological outcomes of magnesium sulfate on children born prematurely.

Impact of Systemic Steroids on Posttonsillectomy Bleeding

Tonsillectomy continues to be one of the most common pediatric surgeries worldwide. Post-operative pain and nausea is common, but the most feared complication, often seen one week post-operatively, is severe bleeding. The use of systemic steroids has long been shown to be an effective treatment option for the prevention of nausea and vomiting; however there is ongoing controversy as to whether its administration increases posttonsillectomy bleeding. In this Japanese cohort study, the charts of 61,430 patients of all ages undergoing tonsillectomy were reviewed. Children in the steroid group had a rate of reoperation for hemostasis under general anesthesia of 1.2% compared to 0.5% in the control group (P < 0.001). This significant difference between the groups was also shown in multivariable logistic regression (OR: 2.50, 95% CI: 1.47-4.23; P  =  0.001). Contrarily, there was no significant difference between the two groups for adults (1.7% vs 1.4%, P  =  0.14), even with multivariable logistic regression (OR: 1.18, 95% CI: 0.85-1.64, P = 0.31). Intravenous steroid administration should be used with caution in children undergoing tonsillectomy.

Clinical and Safety Outcomes Associated With Treatment of Acute Venous Thromboembolism

Venous thromboembolisms continue to be the third leading cause of cardiovascular mortality, highlighting the importance of fully understanding the various anticoagulants available for prevention and treatment. The use of vitamin K antagonists requires frequent laboratory monitoring and careful prevention of possible interactions with other medications. Thus, direct oral anticoagulants including direct Xa inhibitors (rivaroxaban, apixaban, and edoxaban) and a direct thrombin inhibitor (dabigatran) have emerged as possible alternatives. In this meta-analysis, data from 44,989 anticoagulated patients in 45 different trials was analyzed. No statistically significant difference was found in clinical and safety outcomes when comparing most anticoagulants with low-molecular-weight heparin (LMWH) plus vitamin K antagonist. Only unfractionated heparin plus vitamin K antagonist had an increased risk of recurrent venous thromboembolism when compared to LMWH plus vitamin K antagonist (HR: 1.42, 95% CI: 1.15-1.79). When compared to LMWH plus vitamin K antagonist, anticoagulation with rivaroxaban (HR: 0.55, 95% CI: 0.35-0.89) and apixaban (HR: 0.31, 95% CI: 0.15-0.62) had a lower risk of bleeding. Thus, given similarities in efficacy and safety between most anticoagulants, the increase burden with vitamin K antagonists and the decreased bleeding risk of direct Xa inhibitors should be taken into consideration when choosing an anticoagulant.

Image: PD

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