As the optic nerve sheath is continuous with the subarachnoid space of the brain (and is regarded as an extension of the central nervous system ), increased pressure is transmitted through to the optic nerve. The brain itself is relatively spared from pathological consequences of high pressure. However, the anterior end of the optic nerve stops abruptly at the eye. Hence the pressure is asymmetrical and this causes a pinching and protrusion of the optic nerve at its head. The fibers of the retinal ganglion cells of the optic disc become engorged and bulge anteriorly. Persistent and extensive optic nerve head swelling, or optic disc edema, can lead to loss of these fibers and permanent visual impairment.
This is a powerful drug for the control of atrial and ventricular arrhythmias.
The dosage regime is as follows (via a central line):-
300 mgs in 100mls 5 % Dextrose over 1 hour
then 900 mgs in 250 mls 5% Dextrose over 23 hours
The initial oral dose is then 200 mgs tds for 1 week reduced thereafter to bd followed by maintenance od.
( Note. Some has a preference not to use this agent first line and prefers Digoxin)
A DC shock applied to the chest is an effective way of restoring sinus rhythm, particularly supraventricular tachycardia. This is usually carried out by the Cardiologist.
3. Ventricular Arrhythmias
VF\VT - See cardiac arrest
Q. what is "pulmonary edema" and what are the risks? my Dr. told me I'm in a risk group for pulmonary edema, he tried to explain what it is but i didn't understand fully...if someone may give me a brief explanation- I'll appreciate it! A. pulmonary edema occurs when, lets say, your heart left ventricle stops working properly and your right ventricle works fine. that means your lungs getting lets presume- 1 liter of blood -but your left ventricle can pump out of it only 990 ml. that means you have high blood pressure in your lungs and fluid comes out of blood vessels and fills your lungs, making it harder and harder breathing.