Things We Do For No Reason #TWDFNR highlights some widespread practices that are difficult to justify based on lack of proven health benefits, but significant cost (both financial and non-financial harms). Avoid these low value practices and inflated medical bills with tips from expert, Dr Lenny Feldman, MD, FACP, Associate Professor of Medicine Johns Hopkins. Topics include: renal ultrasound and urine electrolytes in acute kidney injury (AKI), folate deficiency and anemia work-up, prealbumin and malnutrition, blood transfusions, shellfish and contrast allergies, monitoring after switch from IV or oral antibiotics, and “against medical advice” discharges.
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Written and produced by: Justin Berk MD, MPH, MBA
Editor: Matthew Watto, MD
Hosts: Justin Berk MD, MPH, MBA; Matthew Watto MD; Paul Williams MD, FACP
Guest: Lenny Feldman MD, FACP
In-depth Show Notes
Impetus for ordering unnecessary labs:
Residents know that a test is unnecessary, but often do so because they want to please their attendings. (Sedrak et al. 2016)
Ordering Urine Electrolytes and Calculating a FeNa
Things We Do For No Reason article: Pahwa & Sperati J Hosp Med 2016
Determination of the fractional excretion of sodium (FeNa) is meant to differentiate two common causes of acute kidney injury (AKI): prerenal azotemia and acute tubular injury (aka ATI or ATN). Hospitalized patients may have both processes contributing to their AKI.
The FeNa test was originally only done in oliguric patients (under 500 mL of urine per day) and in very small sample sizes (Espinel et al. 1976). Dr Feldman says the FeNa and FeUrea testing characteristics are just not good enough to make management decisions.
One exception is in patients with concern for hepatorenal syndrome. Patients with hepatorenal syndrome should have extremely low FeNa and urine sodium as they are sodium avid. If FeNa is elevated, this may help rule out HRS.
Renal ultrasound in AKI:
Renal ultrasounds are only helpful to rule out obstruction. Most AKIs in the hospital are not from obstruction. One study showed it cost $45,000 of renal ultrasounding to find 1 case of interventable hydronephrosis (Licurse set al. Arch Intern Med 2010). [Editor’s note: the study has a algorithm to risk stratify a patient’s potential need for a renal ultrasound as well].
Dr Feldman recommends a bladder ultrasound if there is concern for urinary retention (e.g. from BPH) and to perform a formal renal ultrasound only if there is no identifiable cause of AKI or you have high suspicion for obstruction.
Folate deficiency Things We Do For No Reason article: Breu et al. J Hosp Med 2015
To start, folate deficiency should only be considered in megaloblastic anemia (i.e. an elevated MCV on complete blood count). Grains and cereals have been supplemented with folic acid in the US since 1998 and folate deficiency has dropped precipitously.
Folic acid deficiency is rare and the testing is not accurate. (Latif et a. Clin Lab Haematol 2004).
There are lots of false positive and false negatives. Per Dr Feldman, if you just ate a meal with folate in it, you will get a false elevation – it does not measure what is in the tissues, only in the blood. A normal RBC folate does not rule out folate deficiency.
Since folic acid fortification, the prevalence of folate-deficiency anemia is nearly non-existent (<0.1%) in the United States (Odewole et al. Am J Clin Nutr 2013). The serum folate test has poor utility and significant cost (Theisen-Toupal et al. J Hosp Med 2013). Empiric supplemental therapy is recommended if there’s suspicion for folate deficiency, rather than rely on poor testing for a low prevalence disease (Robinson et al. Am J Med 2001).
Blood transfusions Things We Do For No Reason article: Thakkar et al. J Hosp Med 2017
“Don’t give two when one will do.” Blood transfusions come with risk and costs and are one of the most overutilized medical procedures. Give the minimal effective dose!
Prealbumin as marker for nutrition
Fun fact: Prealbumin is not actually albumin, it is transthyretin (a totally separate molecule). It is responsible for shuttling T4 and vitamin A throughout the body.
An original old study in Senegalese children showed low prealbumin among patients with malnutrition and kwashiorkor. After feeding in hospital, their prealbumin and albumin increased (Ingenbleek et al. Lancet 1972). These children likely had inflammation that was also treated. That’s because albumin (and prealbumin) are negative acute phase reactants i.e. they are decreased in inflammatory states.
Tom Finucane MD, Professor of Geriatric Medicine and Gerontology at Johns Hopkins, looked at non-inflamed, malnourished patients (anorexic patients, or those on hunger strikes) and found their albumin and prealbumin to be normal. Only when the BMI was under 11, or the patient had not eaten for 45 days did the albumin and prealbumin start to drop. At that point, a good clinician should already be able to identify malnourishment (Lee, Finucane et al. Am J Med 2015).
Bottom line: Albumin and prealbumin are not markers of nutrition status and do not identify people with malnutrition or starvation. (Lee, Finucane et al. Am J Med 2015)
Shellfish Allergy / Iodine Things We Do For No Reason article: Narayan et al. J Hosp Med 2016
It was once thought that shellfish allergy was due to iodine. Since IV contrast and shellfish both have iodine, people assumed an allergy to shellfish also meant an allergy to IV contrast. This is such a prevalent myth that in one survey 69% of providers asked about shellfish allergy before radiocontrast administration (Beaty et al. Am J Med 2008).
Serious radiocontrast allergies (e.g. anaphylaxis or anaphylactoid reactions) are extremely rare with an incidence of ~0.1%. A patient with atopy and allergies (admittedly including shellfish) are at a 2-3 times higher risk for radiocontrast allergy (e.g. 2 x 0.1% = 0.2% incidence of serious radiocontrast allergy in patients with atopy and allergies!). DO: Ask patients, “Have you had a serious reaction to radiocontrast injection?”. DON’T: Ask about shellfish or iodine allergies! These questions propagate the myth.
Against Medical Advice Discharge (AMA) Things We Do For No Reason article; Alfandre et al. J Hosp Med 2017
There is no proven utility to discharging patients AMA. Compared to conventional discharge, 25% of AMA-discharged patients reported not wanting to pursue follow-up care. AMA discharges do not provide additional protection from liability and does not affect insurance reimbursement.
IV to PO Antibiotic Switch
Old agencies recommended watching patients for at least 24 hours after switching from IV to PO antibiotics in the hospital. This was before the time of early follow-up appointments. Intravenous antibiotics will stay in the system for several half lives, and if there are going to be problems, they will not happen within 24 hours. Observational studies show observed patients do about the same (if not worse) than the ones that are sent home (Nathan et al. Am J Med 2006). Early switch programs through antibiotic stewardship promise benefits like decreased length of stay, cost, recovery time, and improved patient centered outcomes (Nathwani et al. Clin Microbiol and Infection 2015).
Many oral antibiotics have great bioavailability (. A 2007 Cochrane review of severe urinary tract infections found no evidence that oral antibiotic therapy is less effective than parenteral or initial parenteral therapy.
Goal: Listeners will recognize things we do for now reason aka low value practices with an unfavorable ratio of benefits to cost and/or harm.
After listening to this episode listeners will…
Disclosures: Dr Feldman reports no relevant financial disclosures. The Curbsiders report no relevant financial disclosures.
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