Saturday July 07, 2007

Q: Name atleast 3 causes of false postive result of prolonged PTT ?


Answer:

• Underfilled collecting tube (causing more than required citrate anticoagulant in tube)
• Delay in performing assay (breakdown of cells)
• Polycythemia (causing relatively less plasma volume)

Friday July 06, 2007
Treating cocaine induced hypertension


Cocaine induced hypertension is due to alpha-mediated vasoconstriction. Beta-blockers are advised to be avoided in the setting of cocaine toxicity because they may result in unopposed alpha effects of cocaine and may further increase the blood pressure. There are also some reports of seizures with B-blocker is such situation.

Calcium channel blockers dilate splanchnic vessels and thereby increasing absorption of ingested cocaine from the gastrointestinal tract, which may become disastrous in body packers. Nifedipine is also reported to potentiate the incidence of seizures and death after cocaine administration and should be avoided in the treatment of cocaine-induced hypertension.

Benzodiazepines is the first line of treatment in cocaine-induced hypertension. And if benzodiazepines fail to control hypertension, vasodilators, as nitroprusside and nitroglycerin should be use. And if vasodilators doesn't works, alpha-blockers, such as phentolamine is the next choice.