Local anesthesia for a complex lower lip laceration (Mental nerve block)

A 20-year-old male kick boxer sustains a lower lip laceration during a practice match. The wound is complex and crosses the vermilion border. Which is the best way to achieve anesthesia?

• (A) Local infiltration with 1 percent lidocaine
• (B) Local infiltration with 1 percent lidocaine with epinephrine
• (C) Inferior alveolar nerve block
• (D) Lingular nerve block
• (E) Mental nerve block

answer is E. 

A regional block is preferred for a complex lower lip laceration because it preserves tissue planes and landmarks, facilitating anatomically correct repair. 
The mental nerve supplies the skin and mucus membranes of the lower lip. The mental foramen is located inside the lower lip at its junction with the lower gum, just posterior to the first premolar tooth.

To avoid nerve injury, 1 percent lidocaine with epinephrine is injected close to, but not into, the mental foramen. The inferior alveolar and lingular nerves do not supply the lower lip and thus would not be effective in this patient.

Photo illustration of Actinic Keratosis

Actinic keratoses generally appear as rough, red/brown, scaly macules or papules on the skin. They start to appear usually about age 30 or older.

Actinic keratoses (AKs) are A premalignant neoplasm of the epidermis caused by excessive exposure to sunlight and manifesting as an ill-marginated, erythematous, scaling, rough papule or patch that form on sun exposed areas of the skin, including the scalp, face, forearms, and back of the hands.

Actinic keratoses are usually scaly, feel like sandpaper to the touch, and range in color from skin-toned to reddish-brown " AK are more easily felt than seen, as their overlying scale is thick and firmly adherent".  Actinic keratoses may be as small as the head of a pin or as large as a quarter (or bigger, if left untreated).

Actinic keratoses on the scalp

Actinic keratoses are most common in individuals over 40 years old with fair skin and years of excessive sun exposure. However, even younger people (including those with dark skin) can develop actinic keratoses if they live in very sunny climates.

Lesions are occasionally tender to palpation. Fair-skinned persons, who burn easily and tan poorly, are most commonly affected. A small percentage of AK on non-mucosal skin can progress to skin cancer squamous cell carcinoma. Ultraviolet light exposure induces formation of the lesions.

Arterial catheter placement

This video shows Indications, Allen`s test and Preparation for Arterial catheter placement.

Papillary muscle Rupture

Rupture of a papillary muscle is usually associated with an infarction of which area of myocardium?

• (A) Inferior
• (B) Inferior–posterior
• (C) Lateral
• (D) Anterior
• (E) Anteroseptal

The answer is B.

Papillary muscle rupture is usually associated with an inferior–posterior infarction and involves the posterior papillary muscle. Outcome depends on whether the entire muscle body or only the head is ruptured. Rupture of an entire muscle body is associated with a high mortality rate (up to 50 percent within 24 h).

Diagnosis of papillary muscle dysfunction or rupture may be made on echocardiography or by measuring large V waves in the pulmonary artery wedge pressure with a Swan-Ganz catheter.

Papillary Muscle Infarct with Rupture: Gross, an excellent example of ruptured papillary muscle.