Monday, March 9, 2015

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kussmaul breathing pattern - description and causes

This type of breathing pattern was first described by Adolph Kussmaul, a german physician in 1874. He noticed that his patients with diabetic ketoacidosis had a pattern of breathing which he first labelled as having "air hunger".

In the Kussmaul type of breathing, the patient is breathing heavily i.e hyperventilating along with tachypnea.
So we will find that the amplitude of the breaths along with the rate will be increased.
There is usually no pauses between the breaths.

This is not specific for diabetic ketoacidosis. It can also appear in other types of severe metabolic acidoses e.g alcoholic ketoacidosis .

Sunday, February 15, 2015

Adverse effects of Amiodarone

1) Hypotension can occur especially with the intravenous form due to vasodilation and depressed myocardial performance. Long-term oral therapy can also cause depressed contractility but. it is unusual.

2) Nausea can sometimes be seen during the loading phase. All we have to do is to decrease the daily dose of the medication.

3) Pulmonary fibrosis is the most serious adverse effect during chronic amiodarone therapy. The fibrosis can be rapidly progressive and fatal. The risk factors include: underlying lung disease, doses of 400 mg/day or more and recent pulmonary insults such as pneumonia. Early amiodarone toxicity can be detected using pulmonary function tests and serial chest X-rays.

4) Other adverse effects that may be seen during long-term therapy include
a) corneal microdeposits (which often are asymptomatic),
b) hepatic dysfunction,
c) vivid and disturbing dreams
d) neuromuscular symptoms (most commonly peripheral neuropathy or proximal muscle weakness), e) photosensitivity and
f) hypo- or hyperthyroidism.

Sunday, February 8, 2015

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Aminoglycosides - why -mycin and -micin

The aminoglycoside group includes gentamicin, amikacin, netilmicin, kanamycin, tobramycin, streptomycin, paromomycin and neomycin.

These drugs have a good action against aerobic gram-negative bacteria.

They are rapidly bactericidal. Bacterial killing is concentration dependent: The higher the concentration, the greater is the rate at which bacteria are killed.

As noted above, some of the names end by -micin while others by -mycin. The reason behind this lies in the origin of the antibiotics.

All the antibiotics ending with -mycin are either natural products or semisynthetic derivatives of compounds produced by a variety of soil actinomycetes notably Streptomyces.
Those ending with -micin are derived from other actinomycetes e.g Micromonospora.

Saturday, January 24, 2015

Atrial septal defect device closure

This procedure is called as Atrial septal defect (ASD) device closure.


Transesophageal echocardiography (TEE) is must before procedure for:
1) actual sizing of the defect
2) defining the rims - to hold device in place
3) ruling out anomalous pulmonary venous drainage
4) ruling out significant mitral regurgitation (MR).
Intraprocedural TEE is not mandatory.


N.B How to distinguish between an ASD device and a patent foramen ovale (PFO) device? Left atrial (LA) disk (green arrow) is larger than Right atrial (RA) disk (yellow arrow), thus it is an ASD device.For a PFO device, RA disk will be larger than LA disk.

Further readings:

Friday, January 23, 2015

A case of Mycobacterium marinum infection in a fisherman

Historically recognized as “swimming pool” or “fish tank” granuloma.

Clinical features:
Most infections occur 2 to 3 weeks after contact with contaminated water from one of these sources. The lesions are most often small violet papules on the hands and arms that may progress to shallow, crusty ulcerations and scar formation. Lesions are usually singular. However, multiple ascending lesions resembling sporotrichosis can occasionally occur.
Most patients are clinically healthy with a previous local hand injury that becomes infected while cleaning a fish tank or patients may sustain scratches or puncture wounds from saltwater fish, shrimp, fins and other marine life contaminated with
M. marinum. Swimming pools seem to be a risk only when non-chlorinated.

Diagnosis:
Diagnosis is made from culture and histologic examination of biopsy material, along with a compatible history of exposure.

Treatment:

No treatment of choice is recognized for M. marinum. However, successful treatments have traditionally been a two-drug combination of Rifampin (600 mg/day) plus Ethambutol (15mg/Kg) or monotherapy with Doxycycline, Minocycline (100 mg BD), Clarithromycin (500mg BD) or Trimethoprim-Sulfamethoxazole given for a minimum of 3 months. Clarithromycin has been used increasingly because of good clinical efficacy and minimal side effects, although published experience is limited.








The following is the case of a fisherman who got injured while handling his fishing cage and presented with extensive papular lesions on his forearm. He was started on two drug-combination therapy for 5 months.











The second image is the same patient after 3 months of treatment.