PANCE Review for Physician Assistant Certification Exam Prep + CME

Educational Objective:

Recognize medications that cause rebound hypertension.

Key Point:

For patients who are not compliant with their treatment plan, clonidine is not recommended as hypertensive management.

Explanation:

Of the options listed, clonidine is the only drug that should be avoided to prevent rebound hypertension when skipping a dose. Abrupt cessation of centrally acting alpha-adrenergic agents such as clonidine can cause acute withdrawal syndrome, which is characterized by elevated blood pressure, tachycardia, and diaphoresis. Therefore, use of alpha-adrenergic agents should be avoided in patients with dementia or other situations when doses may be skipped.

Reference:

Hirbe A, et al, eds. Preventive cardiology. In: Godara H. The Washington Manual of Medical Therapeutics. 34th ed., 2014.

Educational Objective

Radiographically identify ankle injury patterns

Key Point

A lack of overlap between the tibia and the fibula, combined with increased space between the medial tibeal malleolus and the talus, is consistent with a grade III ankle sprain.

Explanation

A mortise view of the ankle is a view in which the ankle is internally rotated by 15-35 degrees. This allows better evaluation of the articular surface between the talar dome and tibia. In the above x-ray, the fact that this is a mortise versus an AP view is not relevant to the positive x-ray findings. The patient’s right ankle x-ray shows a lack of overlap between the tibia and the fibula (compare this to the left x-ray), which is a sign of a talofibular syndesmotic injury. In addition, this lack of overlap, together with the patient’s increased space between the medial tibeal malleolus and the talus is consistent with a tear of the deltoid ligament and the anterior talofibular ligament, resulting in a medial shift of the tibia. Thus, this is a grade III injury (see clinical review below) that requires surgical referral. The lack of tibiofibular overlap is a significant x-ray sign that is easily missed. The below left image shows the normal measurements for both the talofibular overlap and the tibial clear space the talofibular clear space (not discussed above – it is the lucency on the tibia immediately next to the medial edge of the fibula). The right image shows another grade III injury with lack of tibiofibular overlap.

The ring structure surrounding the talus is made up of the tibial plafond, medial malleolus, deltoid ligaments, calcaneus, lateral collateral ligaments, and syndesmotic ligaments. The integrity of this ring determines the stability of the ankle. The pictures below demonstrate anterior views of pertinent anatomical details of the right ankle.

Ankle sprains are classified in 3 grades. A grade I injury involves ligamentous stretching without grossly evident tearing or joint instability. A grade II injury involves a partial tear of a ligament with moderate joint instability, often accompanied by significant localized swelling and pain. A grade III injury involves a complete tear of a ligament with marked joint instability and severe edema and ecchymosis. This classification system, although commonly used, fails to characterize ankle injuries involving 2 or more ligaments, and it does not consider nonligamentous injuries.

In general, ligamentous injuries of the ankle follow certain patterns. Approximately two thirds of ankle sprains are isolated anterior talofibular ligament injuries, whereas 20% involve both anterior talofibular and calcaneofibular ligament injuries. In addition, the lateral talocalcaneal ligament may be stressed with an inversion injury, leading to avulsion fractures at either end of the attachment sites. Isolated injury of the deltoid ligament occurs in less than 5% of ankle sprains. Rupture of this ligament occurs most commonly in conjunction with malleolar fractures, especially when an external rotational force is involved. Injuries of the distal tibiofibular syndesmotic ligaments are uncommon in the general population but may represent 10% to 20% of injuries in competitive athletes. Dorsiflexion and external rotation forces usually are responsible for this injury, and may significantly prolong the recovery time with lateral collateral ligament sprains. Isolated calcaneofibular or posterior talofibular ligament injuries are rare.

Reference:
Riyad B. Abu-Laban and Kendall Ho. Marx: Rosen's Emergency Medicine, 7th ed.: Mosby; 2009. CHAPTER 55 - Ankle and Foot

The 2015 Centers of Disease Control and Prevention (CDC) guidelines recommend azithromycin 1 g as a single oral dose (doxycycline.100 mg bid for 7 days is the alternative) for chlamydial infection. Azithromycin has significant tissue half-life; thus, a single dose of azithromycin is sufficient to treat chlamydial infection, which leads to far more patient compliance than multiple doses of erythromycin or amoxicillin.

Chlamydia is the most common sexually transmitted bacterial infection in the United States. Chlamydial infection must be treated to avoid transmission of infection to other sexual partners, so withholding treatment is not appropriate.

Levofloxacin, penicillin, and streptomycin have far less efficacy in treating chlamydial infection compared with azithromycin or erythromycin.

* In the 2014 guidelines for gonorrhea and chlamydial infections and in the 2015 guidelines for sexually transmitted infections, the Centers for Disease Control and Prevention (CDC) identifies nucleic acid amplification tests (NAATs) as the new gold standard lab test for detecting both N. gonorrhoeae and Chlamydia trachomatis in all adult patients who either have genital symptoms or require screening for these two organisms (vaginal swabs in women and first catch urine in men).

The CDC suggest that cultures rather than NAATs might remain preferable when (1) testing extra-genital sites (oropharyngeal or rectal) in prepubescent girls (2) evaluating child sexual assault involving boys, and 3) evaluating cases of treatment failure, (4) monitoring antibiotic susceptibility.

Though studies look promising and the CDC does not directly recommend against the use of NAATs for extragenital specimens (rectal/oropharyngeal), the FDA has not yet cleared the use of NAATs for extragenital sites.

The 2014 CDC guidelines state that older non-culture tests, such as enzyme immunoassays, nucleic acid probe tests, and genetic transformation tests are no longer recommended because they have less sensitivity, specificity, and ease of transport than NAATs.

The turn-around time for a NAAT test is about 3-5 hours.

References:

Workowski KA, Bolan GA. Sexually Transmitted Diseases Treatment Guidelines, 2015. MMWR Recomm Rep 2015; 64 (No 3): pgs 52-53.

Birnbaumer DM. Sexually Transmitted Diseases. Chpt 98 in Rosen's Emergency Medicine. 8th ed. 2014.

Centers for Disease Control and Prevention (CDC). Update to CDC's sexually transmitted diseases treatment guidelines, 2014: Recommendations for the Laboratory-Based Detection of Chlamydia trachomatis and Neisseria gonorrhoeae — 2014.

Beware of the temptation to diagnose all cases of "bladder pain" and pyuria as urinary tract infections, or a surgical emergency will occasionally be overlooked.

Factitial ulcers are caused by intentional self-inflicted trauma and by repetitive mechanical trauma or application of acids, caustics or other ulcerative substances. These patients often have severe personality disorders or psychoses.. It may be induced for secondary gain or as a result of other psychologic disorders.

Lesion Characteristics

Color: Red

Lesion morphology: exudates and crusts, scarring, ulcers. These lesions have an "outside job" appearance, with well-demarcated borders and geometric, angular, stellate, linear or other unnatural appearing shapes.

Location and Grouping: Variable, but always in an area accessible to self manipulation.

Historical Findings and Course: Patients may appear to overreact to questions about the origin of such lesions, or vigorously deny any suggestion of self-manipulation.

Associated Medical Conditions and Risk Factors: schizophrenia and personality disorders, especially borderline personality.

Treatment: Psychiatric follow-up is important, but patients often resist this form of therapy. The usual medical treatments should be applied, but are unlikely to be effective due to non-compliance. When "unmasked," patients are usually lost to medical follow up for these lesions.

Differential Diagnosis:

• Other types of ulcers (e.g., stasis ulcers, vasculitic ulcers, etc.).
• Allergic contact dermatitis (may be well demarcated, angular and linear, but does not present as an ulcer).
• Brown recluse spider bite (causes cellulitis with subsequent necrosis, but is not recurrent).