Nearly every known counter-irritant or rubefacient application has been employed, but none is so efficacious as Cantharidin; the most frequently used is Strong Tincture of Iodine.
Agents known as Resolvents or Discutients are also employed locally, as weak Tincture of Iodine, Jothion, Lin. Pot. Tod. cum Sapone, Oleate of Mercury, &c. The best results from such drugs may be obtained by applying weak Mercurial Ointment or the Oleate on lint and firmly strap ping over it with rubber plaster as already described.
Internal administration of powerful diuretics like Calomel, Squill, Digitalis, Salicylates, Diuretin, &c., is generally useless, and continuous dosage by strong saline purgatives like concentrated solution of Magnesia Sulphate seldom produces any diminution of the effusion, though when this is of large bulk the last-mentioned drug sometimes appears to markedly reduce the amount of fluid if given after a long fast.
The value of a dry diet such as biscuit, old cheese and stale bread has been greatly exaggerated; it has been stated to possess some power in effusions, but this is ere doubtful, and some physicians report that a purely fluid diet (t' to i pints daily) should he administered.
Speaking it should be kept in mind that the drug or diet treatment of an inflammatory effusion is much less satisfactory than is the dissipation of it passive thopsy in serous cavities.
Whilst the above measures—blistering. &c.—may fairly have a trial for a time in the instance of small effusions, there should be no doubt about the imperative necessity of surgical interference in all cases where the pleural cavity on oneside contains fluid up to the level of the third rib. thcdulnuss LAtends to near the Ha ? idle when the case first comes under the cire of the physician. sonic fluid should be drawn off without any delay. With a dulness extending above the angle of the scapula which has lasted for three or four weeks the Same Immediate operation is demanded in the presence of marked displacement of organs, though the breathing is not interfered with and the signs on examination fail to show that the sac is greatly distended. In a double pleurisy with each pleural
cavity only half filled itlt fluid there should he no procrastination.
'I'%\ dan:lers confront the physician in all such cases if tapping be deli rred— one is the 'emote liability of sudden syncope, the other is the risk of permitting the compressed lung to become hopelessly bound down by tensi ye adhesions.
Thoracocentesis should always lie preceded hy a A erification of fluid by means of the hypodermic' syringe; when this precaution is undertaken the site of the aspirating puncture becomes a 'natter of minor importance. belore the hypodermic needle a little sterilised liquid should he left in the syrim_ti. a few drops of which may be injected should the needle blocked.
The best site for puncture under ordinary circumstances is the lateral region of the thorax in the mid axillary line in any intercostal space from the fourth to the eighth: a common mistake is to go below the eighth space. Many operators prefer the neighbourhood of the angle of the srapula in the seventh or eighth spite. The patient should lie in the lying posture on the sound side and partially on his kick. Some surgeons recommend the posture, but this is not advisable. The needle or trod ar and eanula should he pushed smartly into the centre of the inter c or Hose to the upper border of tile rib, so as to avoid the inter costal artery. A spray of Ethyl Chloride may lie employed to freeze the skin and render the puncture pitiless. Aspiration should lie gently and do wratcly performed, only a slow withdrawal of the piston of the syringe net NVIien P(itainis instrument is employed the exhaustion of the air in the little should net er Is complete at the beginning of the tapping'. tout half of a lar;_e effusion should be drawn off, and as a rule i quart of fluid is enote_li. If the plan of siphonage by means of a fine Southey's tube he employed the entire fluid may lie safely evacuated owing to the slowness with which the fluid is withdrawn.