4 Tips for new medical residents

Since July is here and the academic calendar is starting over, it is time for new medical residents to be arriving to the hospital floors.  With this in mind, here are a few tips to help in the transition from student to physician.

Argatroban and warfarin dosing in heparin-induced thrombocytopenia

Let’s start with a patient case.  A 45 year old woman is referred to the hospital after seeing her primary care physician for unusual bruising.  She was discharged four days ago after a two day hospitalization for an asthma exacerbation.  Her PMH includes HTN and asthma.  Her CBC reveals platelets of 73 (baseline 190) and the comprehensive metabolic panel and CBC are otherwise within normal limits.  The diagnosis of heparin-induced thrombocytopenia (HIT) is suspected since she received heparin for DVT prophylaxis during her recent hospitalization.

To see another post on how to determine the probability of HIT by using the 4 T's score, click here.

If the diagnosis of HIT is confirmed, discontinuation of all forms of heparin is paramount.  This includes unfractionated heparin and low molecular weight heparins (including flushes and heparin-coated catheters).

After diagnosis, the decision needs to be made whether to institute a non-heparin anticoagulant, a vitamin K antagonist, and/or simply discontinue all heparins.

Update to anticoagulation in atrial fibrillation

Let’s start with a patient case. A 72 year old female presents to the hospital with fatigue, palpitations, and shortness of breath that has occurred intermittently over the last two weeks.  Her PMH is significant for anxiety, seasonal allergies, and PAD which is rarely symptomatic and not lifestyle-limiting.  She is admitted to the hospital with the diagnosis new-onset atrial fibrillation.  What anticoagulation strategy is recommended for someone like this?

This pharmacy pearl highlights just a few of the key points regarding anticoagulation from the 2014 AHA/ACC/HRS Guideline for the management of patients with atrial fibrillation which was just published in April of this year.¹  There are several differences between this newest guideline and the most recent version of the Chest guidelines from 2012 (which only addressed warfarin and dabigatran since it was the only new oral anticoagulant approved at the time).  Note that this entire summary will be referring to nonvalvular atrial fibrillation.

False-positives in urine drug screening caused by medications

Testing urine for the presence of drugs has a variety of uses including assessing poisoning or overdose, pre-employment testing, substance abuse treatment monitoring, or other medicolegal purposes.  There are a number of common medications that can cause false-positive screening of these tests which can lead to a variety of ramifications.

Initial tests are usually performed with an immunoassay.  These can generally be done quickly (an hour or two) and inexpensively and vary in their sensitivity.  They may miss particular substances (for opioids in particular – synthetic or semisynthetic opioids such as hydrocodone, oxycodone, fentanyl, or methadone may not test positive on the initial immunoassay) so if you’re suspicious/concerned about a certain agent, let the lab know so the correct test is performed.  Following the immunoassay, positive results can be confirmed with a more specific technique such as gas chromatography or mass spectrometry but these tests are more costly and time consuming so results may not be available for hours to days. 

Here is a table of medications that can cause false-positives on the urine immunoassay and some comments about the caveats of each category.

Update on steroid recommendations for COPD exacerbations

Let’s start with a patient case.  An elderly patient is admitted through the emergency department with markedly worsening dyspnea and purulent sputum production over the last three days.  When reviewing his history, you find that he has GOLD grade 4 (very severe) COPD and experiences roughly one exacerbation per year that requires hospitalization.  His home medications for COPD include tiotropium (Spiriva) 18 mcg/inhalation once daily, albuterol MDI (Proventil HFA, ProAir HFA, or Ventolin HFA) 90 mcg/inhalation 2 inhalations every 4-6 hours as needed for dyspnea, and fluticasone/salmeterol (Advair Diskus) 250/50 mcg inhaled twice daily.  You are now deciding what steroid regimen should be initiated to manage this exacerbation.

Risk factors for stress ulcers and stress ulcer prophylaxis

Stress ulcer prophylaxis is a topic that comes up frequently on the internal medicine service but is not frequently given more than a moment of consideration.  Numerous studies have identified how acid-suppressive therapies (eg. namely proton pump inhibitors and histamine-2 receptor antagonists) are widely prescribed and often lacking an indication.  Studies of various designs have revealed that 46-73% of patients who receive acid-suppressive therapy while hospitalized do not have an indication.^1-3 

The most robust guideline to date for the use of acid-suppressive therapy for stress ulcer prophylaxis was published in 1999 and was comprised of data almost entirely from patients in the intensive care unit (ICU).⁴  At that time, there was only one randomized control trial addressing stress ulcer prophylaxis in the non-ICU setting.  These guidelines identified and determined the weight of various risk factors for the development of stress ulcers and these values are continued to be used today.  The presence or absence or risk factors should be used to determine the need for stress ulcer prophylaxis, not just admission to the ICU.  The summary of recommendations follows below.