The sterilized paraffin syringe should not be handled until the hands
have been scrubbed. The washers and needles, just before using, should
be removed from the alcohol solution. It is unnecessary to wash the
alcohol from the fingers, washers or needles, in fact, it is
preferable to leave it upon them.
Using an extra large syringe it is possible to operate upon several
patients without resterilizing the syringe. This instrument may be
soaked in the alcohol solution, the needle changed and the operator
may continue until the syringe is empty.
Even though one have a syringe capable of holding enough for several
operations it is well to have a second at hand ready for use as the
instruments sometimes break or spring a leak when least expected.
Never use a syringe which leaks, as one cannot tell how much is going
into the tissues and how much is escaping. Leaks invariably occur at
the side of the needle base or at the point of juncture of the barrel
of the instrument with its anterior portion. Paraffin in the solid
state will seldom if ever escape along the side of the plunger within
the barrel of the instrument when the all metal paraffin syringe is
used and the all metal syringe is the only instrument which should be
used for paraffin injections.
The screw piston is preferable to the sliding piston under all
circumstances as it gives the operator a better control over the
injection. Injections are made with the paraffin compounds cold so
that considerable pressure must be brought to bear to cause the harder
mixtures to flow through a long needle.