Saturday, 30 July 2011

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.

Thursday, 28 July 2011

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.

Wednesday, 27 July 2011

Arterial catheter placement

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

Friday, 22 July 2011

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.

How to remember Carpal bones !!

"She Looks Too Pretty; Try To Catch Her":
· Proximal row then distal row, both lateral-to-medial:
  • Scaphoid
  • Lunate
  • Triquetrium
  • Pisiform
  • Trapezium
  • Trapezoid
  • Capate
  • Hamate
· Alternatively: "She Likes To Play; Try To Catch Her".

Note :The scaphoid bone is a small carpal bone on the thumb side (radial side) of the wrist. It is the most commonly fractured carpal bone.

This is probably because it actually crosses two rows of carpal bones, forming a hinge.

Saturday, 9 July 2011

Evaluation of groin pain

A 70-year-old female with mild dementia complains of unilateral groin pain. There is some limitation of motion in the right hip. Which of the following is the most appropriate first step in evaluation?
  • a.CBC and erythrocyte sedimentation rate
  • b.Rheumatoid factor
  • c.X-ray of right hip
  • d.Bone scan

The answer is c.
Hip pain may result from fracture, bursitis, arthritis, tumor, or pain referred from the lumbosacral spine. A film of the right hip is mandatory in this patient. Fracture of the hip must be ruled out, particularly in a woman with mental status abnormalities, who may be prone to falls. Elderly women with osteoporosis are most prone to hip fracture.

Pain from the hip joint is most often felt in the groin radiating down the anterior thigh. It is important to realize that patients will often complain of “hip” pain when they mean pain in the buttocks or low back. Pain in the buttocks is most often referred pain from the spine.

Wednesday, 6 July 2011

Surface anatomy of both kidneys on the back

Viewed posteriorly the right kidney has its upper edge opposite the 11th dorsal spine and the lower edge of the 11th rib. Its lower edge is opposite the upper edges of L3 spine and vertebral body and about 4 cm. (1 1/2 in.) above the highest point of the crest of the ileum, which is opposite the fourth spine.The left kidney is usually 1.25 cm. (1/2 in.) higher, but being a little longer than the right, its lower limit may not be quite that much higher. The kidney is slightly lower in women and children than in men. The inner border reaches 10 cm. (4 in. ) and the hilum 4 to 5 cm. (1 1/2 to 2 in.)
Notice that the left kidney is higher (highest border T11 lowest border L2) whereas the right kidney is lower (highest border T12 lowest border L3). The right kidney is less enclosed by the rib cage, because of the presence of right lobe of liver above it, therefore pushing it down. So, the right kidney is palpable during inspiration (moves down by 1 inch).

The renal angle as seen in the image, is located between the

-lower border of the 12th rib
-& lateral border of the erector spinae muscle
Left kidney related to 11th & 12th rib. Right kidney related to only 12th rib.

 Also to indicate the position of the kidney from the back, the parallellogram of Morris is used; two vertical lines are drawn, the first 2.5 cm., the second 9.5 cm. from the middle line; the parallelogram is completed by two horizontal lines drawn respectively at the levels of the tips of the spinous process of the eleventh thoracic and the lower border of the spinous process of the third lumbar vertebra. The hilum is 5 cm. from the middle line at the level of the spinous process of the first lumbar vertebra.
  Back of lumbar region, showing surface markings for kidneys, ureters, and spleen. The lower portions of the lung and pleura are shown on the right side.

Sunday, 3 July 2011

Antinucleolar antibody in diagnosis of Scleroderma

A 45-year-old woman has pain in her fingers on exposure to cold, arthralgias, and difficulty swallowing solid food. Of the following tests,which, if positive, would be most supportive of a definitive diagnosis?
  • a.Rheumatoid factor
  • b.Antinucleolar antibody
  • c.ECG
  • d.BUN and creatinine
  • e.Reproduction of symptoms and findings by immersion of hands in cold water

The answer is b.
The symptoms of Raynaud’s phenomenon, arthralgia, and dysphagia point toward the diagnosis of scleroderma. Scleroderma, or systemic sclerosis, is characterized by a systemic vasculopathy of small and medium-sized vessels, excessive collagen deposition in tissues, and an abnormal immune system. It is an uncommon multisystem disease affecting women more often than men. There are two variants of scleroderma ;a relatively benign type called the CREST syndrome "C-calcinosis.R- raynaud phen. E- esophagal dysmotility.S-sclerodactyly.T-talangiectasia" and a more severe, diffuse disease.

Antinucleolar antibody occurs in only 20 to 30% of patients with the disease, but a positive test is highly specific. Cardiac involvement may occur, and an ECG could show heart block or pericardial involvement but is not at all specific. Renal failure can develop insidiously. Rheumatoid factor is nonspecific and present in 20%
of patients with scleroderma. Reproduction of Raynaud’s phenomena is nonspecific and is not recommended as an office test.
The clinical spectrum of scleroderma
The spectrum of sclerodermatous diseases comprises a wide variety of clinical entities such as morphea (patchy, linear, generalized), pseudo-scleroderma and the overlap-syndromes with similar cutaneous and histopathologic manifestations.

Saturday, 2 July 2011

Ultrasound Guided Femoral Nerve Block for Large Thigh Laceration

Here is a quick case study on ultrasound guided regional anesthesia from the Emergency Ultrasound Nerve Block Project.