Chiefs’ Inquiry Corner 7/22/2019

July 22, 2019


Being an outstanding physician and lifelong learner requires stoking the flames of clinical curiosity.  In Chiefs’ Inquiry Corner (CIC) we attempt to succinctly answer actual clinical questions that have been raised on the wards and in the clinics of NYU’s teaching hospitals.  Our answers are not meant to be all encompassing or practice changing but rather to serve as springboards for further exploration. For those of us with short attention spans, we hope CIC satisfies that craving for a morsel of knowledge in a digestible format.

 

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Clarithromycin-amoxicillin-PPI for 14 days remains one of several recommended treatment regimens for H. pylori. However, there is concern worldwide about the growing prevalence of clarithromycin-resistant strains. According to the American College of Gastroenterology guidelines from 2017, all patients should be asked about previous macrolide exposure for any reason, as this itself can confer resistance. Research has suggested deferring a clarithromycin-based regimen when local resistance rates exceed 15-20%. Little data is available about North American resistance patterns, but suspicion holds that metropolitan areas may exceed the 20% cut-off. Nearest to us? An Edison, NJ study of clarithromycin-based therapy found only 14% treatment failure. But that’s New Jersey.

References: ACG Clinical Guidelines  
Blood gas analysis can expedite care for critically ill patients by giving clinicians access to critical laboratory data while awaiting results from venous analyzers. In addition to providing information about a patient’s acid-base status and oxygenation, modern blood gas machines can also measure serum electrolyte and hemoglobin concentrations. However, in a study that compared results from 100 simultaneous blood gas and venous samplings, the hemoglobin concentration differed by an average of 0.91 g/dL with a range of 0-4.3 g/dL (p<0.012). Thus, while the hemoglobin on the blood gas can provide a rough estimate that may be useful in a critical setting, the true hemoglobin concentration should always be confirmed by standard venous analyzers.

References: ABG Hb  
Many patients with symptomatic heart failure are iron deficient and may benefit from aggressive repletion. A large, multicenter, randomized controlled trial compared intravenous (IV) ferric carboxymaltose versus placebo in patients with symptomatic heart failure and iron deficiency, defined as ferritin <100 ug/L or ferritin 100-299 ug/L with transferrin saturation <20%. At 24 weeks, the group that received IV iron had significantly improved NYHA functional class, 6-minute walk test, and quality of life, independent of the presence or absence of actual anemia (FAIR-HF). These findings were sustained in patients treated with a prolonged, one-year course IV ferric carboxymaltose (CONFIRM-HF), supporting a significant role for IV iron therapy to improve patient-centered outcomes among those with heart failure and iron deficiency.

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