Of the PARACENTESIS.
THIS Operation is an Opening made into the Abdomen, in order to empty any Quantity of extravasated Water, collected in that Species of Dropsy called the Ascites; but as there is much more Difficulty in learning when to perform than how to perform it, and indeed in some Instances requires the nicest judgment; I shall endeavour to specify the Distinctions which render the Undertaking more or less proper.
There are but two kinds of Dropsy; the Anasarca, called also Leucophlegmacy, when the extravasated Water swims in the Cells of the Membrana Adiposa; and the Ascites, when the Water possesses the Cavity of the Abdomen: In the first kind, the Water is clear and limpid, but in the second, a little grosser, very often gelatinous and corrupted, and sometimes even mixed with fleshy Concretions. I do not mention the Tympany or flatulent Dropsy of the Abdomen; nor have I in the Chapter of Hernias spoke of the Hernia Ventosa, it being certain that the Asicites and Bubonocele, have generally been mistaken for those Diseases; tho' there are some few Instances where an enormous Tumour of the Abdomen, arises from excessive Flatulencies, and Distensions of the Intestines.
It is of no great Consequence in the Practice of Physick or Surgery, whether the Water is discharged by a Rupture of the Lymphaticks, or a Transudation thro' the Pores of their relaxed Coats, since the Fact is established, that they have a Power sometimes of absorbing the Fluid, lying thus loose, and conveying it into the Course of the Circulation; after which, it is often totally carried off, by some Emunctory of the Body. The great Disposition there is in Nature, to fix upon the Kidneys and Glands of the Intestines for this End, has put Physicians upon promoting it by Catharticks and Diureticks, which sometimes entirely carry off the Distemper. If any One should doubt of the possibility of a Cure when the Water is extravasated, let him inject thro' a small Opening into the Thorax or Abdomen of a Dog, a Pint of warm Water, and upon Dissection some few Hours after, he shall not find one Drop left there; which puts out of Dispute this power of Absorption: But indeed, tho' we do not much attend to it, 'tis by this very Act, the Circulation is carried on regularly, with respect to some if not all the Secretions, which would overload their Receptacles, if they were not thus taken up again. The Example serving for Illustration, may be the Circulation of the aqueous Humour of the Eye, which no one questions, is an extravasated Fluid.
The Operation of Tapping, is seldom the Cure of the Distemper; but Dropsies, which are the Consequence of a mere Impoverishment of the Blood, are less likely to return than those which are owing to any previous Disorder of the Liver; and it is not uncommon for Dropsies that follow Agues, Hæmorrhages, and Diarrhas, to do well; whereas in such as are complicated with a scirrhous Liver, there is hardly an Example of a Cure.
The Water floating in the Belly, is by its Fluctuation to determine whether the Operation be adviseable; for, if by laying one Hand on any Part of the Abdomen, you cannot feel an Undulation from striking on an opposite Part, with the other, it is to be presumed there will be some Obstacle to the Evacuation. It sometimes happens, that a great Quantity, or almost all the Water, is contained in little Bladders, adhering to the Liver and the Surface of the Peritonæum, known by the Name of Hydatids, and the rest of it in different sized ones, from the degree of a Hydatid, to the Size of a Globe holding half a Pint, or a Pint of Water. This is called the Encysted Dropsy, and from the Smallness of its Cysts, makes the Operation useless, but is not difficult to be distinguished, because there is not a Fluctuation of the Water, unless it is complicated with an Extravasation.
When the Fluctuation is hardly perceptible, (except the Teguments of the Abdomen are very much thickened by an Anasarca) in all probability, the Fluid is gelatinous: I have had Instances, where it was too viscid to pass thro' a common Trocar; on which account it is proper to be furnished with a couple, of the Size described in the Copper-plate. I once tapped a Person when the Fluid would not pass even thro' the large one; so to ease him from the Distension he laboured under, I dilated the Orifice with a large Sponge-tent, and afterwards extracted a prodigious Quantity of distinct concreted Hyatids, differing in nothing, as I could discover, from the nature of a Polypus formed in the Nose.
There is another kind of Dropsy, which for the most part forbids the Operation, and is peculiar to Women, being seated in the Body of one or both Ovaries. There is, I believe, no Example of this Species but what may be known by the Hardness and Irregularity of the Tumour of the Abdomen, which is nearly uniform in the other Cases.
When the Ovary is Dropsical, the Water is generally deposited in a great number of Cells formed in the Body of it, which Circumstance makes the Fluctuation insensible, and the Perforation useless; tho' sometimes there are only one or two Cells., in which case, if the Ovary is greatly magnified, the Undulation will be readily felt, and the Operation be adviseable. I once tapped a Gentlewoman in this Circumstance, whose Ovary upon the Puncture yielded but half a Pint of Water, but being still persuaded by the Feel, that there was a large Cyst, I tapped her in another Part, and drew away near a Gallon: I had an Opportunity after her Death, to be convinced of this Fact, by examining the Body.
When the Ascites and Anasarca are complicated, it is seldom proper to perform the Operation, since the Water may be much more effectually evacuated by Scarifications in the Legs, than by Tapping.
Upon the Supposition nothing forbids the Extraction of the Water, the Manner of Operating is this: Having placed the Patient in a Chair of a convenient Height, let him join his Hands so as to press upon his Stomach; then dipping the Trocar in Oil, you stab it suddenly through the Teguments, and withdrawing the Perforator, leave the Waters to empty by the Canula: the Abdomen being, when filled, in the circumstance of a Bladder distended with a Fluid, would make it indifferent where to wound; but the Apprehension of hurting the Liver, if it be much enlarged, has induced Operators rather to choose the left side, and generally in that Part, which is about three Inches obliquely below the Navel: If the Navel protuberates, you may make a small Puncture with a Lancet, through the Skin, and the Waters will be readily voided by that Orifice, without any danger of a Hernia succeeding, as is apprehended by many Writers; though it should be carefully attended to, whether the Protuberance is formed by the Water or an Exomphalos, in which latter Case the Intestine would be wounded, and not without the greatest danger. The Surgeon neither in opening with the Lancet, nor perforating with the Trocar, need fear injuring the Intestines, unless there is but little Water in the Abdomen, since they are too much confined by the Mesentery, to come within reach of Danger from these Instruments; but it sometimes happens, that when the Water is almost all emptied, it is suddenly stopped by the Intestine or Omentum pressing against the end of the Canula; in which case you may push them away with a Probe: During the Evacuation, your Assistants must keep pressing on each side of the Abdomen with a Force equal to that of the Waters before contained there; for by neglecting this Rule, the Patient will be apt to fall into Faintings, from the Weight on the great Vessels of the Abdomen being taken off, and the sinking of the Diaphragm succeeding; in consequence of which, more Blood flowing into the inferior Vessels than usual, leaves the superior ones of a sudden too empty, and thus interrupts the regular Progress of the Circulation,. To obviate this Inconvenience, the Compression must not only be made with the Hands during the Operation, but be afterwards continued, by swathing the Abdomen with a Roller of Flannel, about eight Yards long, and five Inches broad, beginning at the bottom of the Belly, so that the Intestines may be born up against the Diaphragm: You may change the Roller every Day, 'till the third or fourth Day, by which time, the several Parts will have acquired their due Tone. For the Dressing, a piece of dry Lint and Plaister suffice; but between the Skin and Roller it may be proper to lay a double Flannel a Foot square, dipt in Brandy or Spirits of Wine. This Operation, though it does not often absolutely cure, yet it sometimes preserves Life a great many Years, and even a pleasant one, especially if the Waters have been long collecting. I have known several Instances of People being tapped once a Month, for many Years, who felt no Disorder in the Intervals, 'till towards the time of the Operation, when the Distension grew painful; and there are Instances, where the Patient has not relapsed after it. Upon the whole, there is so little Pain or Danger in the Operation, that in consideration of the great Benefits sometimes received from it, I cannot but recommend it as exceedingly useful.
The EXPLANATION.
A. A Trocar of the moll convenient size for emptying the Abdomen, when the Water is not gelatinous. It is here represented with the Perforator in the Canula, just as it is placed when we perform the Operation.
B. The Canula of a large Trocar, which I have recommended in Cases where the Water is gelatinous.
C. The Perforator of the large Trocar.
The Handle of the Trocar is generally made of Wood, the Canula of Silver, and the Perforator of Steel; great care should be taken by the Makers of this Instrument, that the Perforator should exactly fill up the Cavity of the Canula; for unless the Extremity of the Canula lies quite close and smooth on the Perforator, the Introduction of it into the Abdomen will be very painful: To make it slip in more easily, the Edge of the Extremity of the Canula should be thin and sharp; and I would recommend, that the Canula be Steel, for the Silver one being of too soft a Metal becomes jagged or bruised at its Extremity with very little use. After the Operation, the Canula must be wiped clean and dry, by drawing a Slip or two of Flannel thro' it; otherwise, when the Perforator is put into it., they will both grow rusty.