half an inch, (which is the fize of the one represented in the plate), may be used.

CHAP. VIII.

OF THE PARACENTESIS OF THE
ABDOMEN.

THIS

HIS operation becomes neceffary, when any confiderable quantity of aqueous fluid is collected in the cavity of the abdomen, and cannot be difpelled by any affiftance of medicine. The paracentefis confifts merely in letting it off, in order to give the patient fome ease for the prefent moment; for it is feldom that it accomplifhes a cure, or prolongs life. Sometimes it even proves unsuccessful for obtaining that end for which it is properly calculated; as, when the water is confined in cyfts, forming hydatids, or when it is fo thick and viscous, that it cannot flow out through the canula introduced for its paffage. It is, however, attended with very little pain; and there are many instances of its having been performed a great number of times upon one patient, whofe life has thus been prolonged for a confiderable time. The operation ought therefore always to be performed, where

the patient is much distressed, and there is good reafon to hope that the fluid is fufficiently thin to be evacuated. This may generally be known from a fluctuation in the belly when ftruck upon one fide; the undulation being communicated to the fingers on the oppofite fide, and from the fwelling being equally diffufed over the whole. abdomen. The figns of the operation being neceffary, are an extreme oppreffion and difficulty of breathing, an inability to lie in an horizontal posture, great anxiety and want of reft, &c. When the fwelling has the appearance just mentioned, there is reafon to hope that the patient may be relieved; but not if it is unequal, without any perceptible fluctuation. Sometimes indeed, in females, a great quantity of water is collected in one or both the ovaria, in which cafe the fluid may likewife be drawn off with advantage to the patient, even though the tumor be lefs equal, and have lefs fluctuation than in other cafes.

In dropfies, as in almost all other chirurgical cafes, it will be proper to let the disease run on for as fhort a time as poffible before the operation is performed; for the water being in immediate contact with the viscera, communicates to them a putrefcent tendency, and not only to them but to the whole body, a gangrenous difpofition, which continually increases; and hence VOL. II. wounds

M

Chap. VIII. wounds in dropfical people heal with much more difficulty than in others, nay fometimes mortify from the flighteft caufes. As foon therefore as internal remedies are found infufficient, recourfe ought to be had to the paracentefis; and it is not without great probability that some practitioners attribute the little fuccefs that attends the operation to its being fo often delayed beyond its due time.

In former times, the paracentefis was reckoned a very dangerous operation; the patient being very liable to faintings after the water was drawn off, nay fometimes to fudden death. This was owing to the too quick removal of the preffure to which the viscera had been accuftomed; and, as the fatal symptoms arofe from this caufe, fo they were eafily removed by fubftitut. ing an artificial preffure during the time that the water was drawing off, and for fome time after, instead of that which had been produced by the water. The beft contrivance for making this preffure, is by a kind of belt invented by the late Dr Monro, and reprefented, Plate 2. Fig. 2. the use and manner of applying which are evident from infpection.

The proper inftrument for performing the paracentefis, is a trocar with a canula for letting off the water; but, till of late, the best form of

it has not been determined. Formerly the tro

car

car had a triangular point, the reft of it being of a cylindrical fhape. By this it was found. difficult to perforate the integuments, and a flat one was next tried, where the point of the trocar resembled that of a lancet. This was found to answer much better; but, as in this inftrument the canula confifted of two parts which forcibly fell together when the ftilette was withdrawn, there was danger of them catching a part of the inteftine. The inftrument reprefented Plate 2. Fig. 3. is not liable to this objection, and is amongst the beft hitherto invented. Different

fizes are there to be seen.

The most proper place for performing the paracentefis, is at about an equal distance between the umbilicus and spine of the ilium on the left fide, where there are no large blood vessels, and the parts to be penetrated are rather fleshy than tendinous, and confequently not difficult to be healed. When it is to be performed, the patient ought to be laid in an horizontal posture, the part to be pierced, having been previously marked with ink; one of the openings of the bandage ought to be brought directly before this marked place, the straps fomewhat tightened by means of the buckles, and the fide to be perforated ought to be over the edge of the bed. The furgeon then is to push the trocar through the skin only, till the point of the stilette and a quarter of an inch of the

canula

2

canula have paffed below it, he is now to direct its point with his forefinger and push it through the mufcles, until he is fatisfied that the extremity of the canula has reached the water, fo that it can flow out through it; and this he will always know, when no farther resistance is made to the inftrument. When this is found to be the cafe, he must withdraw the ftilette, and allow the water to flow out as long as it will, taking care always to pull the ftraps tighter and tighter as the water is discharged. Should the patient, however, happen to become faintifh, the efflux of water may be stopped for a few minutes, by the furgeon putting his finger on the orifice of the canula. When all the water has run off, the wound may be dreffed fuperficially with a pledget spread with any fimple ointment, the bandage is still to be continued pretty tight, not only to prevent the faintnefs already mentioned, fo dangerous to the patient, but likewife a return of the disorder, to which in fome cafes it is probable it may contribute; the strength of the patient is to be recruited with cordials and a nourishing diet, in order to corroborate the fyftem, and thus take off the relaxation which originally induced the difeafe; but, as it is very feldom that this takes place, the only thing that can be done is to have recourfe to the operation again, as foon as it appears to be neceffa

ry.