Clinical Conferences IN MIDWIFERY
ESPECIALLY IN RELATION TO THE USE OF THE FORCEPS. GENTLEMEN,—The subject which I propose to discuss on the prevent occasion is that of the arrest of the fcetal head in the cavity of the pelvis. In two of the preceding lectures we have considered some points in the management of cases where the becomes arrested at the brim of the pelvis, and before it has become thoroughly engaged in the cavity. The very important class of cases now to be considered are those in which the head has passed the
... has passed the brim of the pelvis, but becomes arrested in its cavity. I shall endeavour to point out to you the diagnosis of these cases, and to indicate the appropriate treatment. In most of these cases, where the head, having passed the brim, has ent< red the cavity of the pelvis, the labour has advanced to what is technically called the second stage, the os utari being either dilated to a considerable size or in a very dilatable condition. It now and then happens, however, that the head descends very low in the pelvic cavity, the os remain. ing closed for some little time after such descent, while the membranes may or may not have been ruptured. Thus, in fact, the head may be arrested in the pelvis before the second stage of labour has set in. I have in previous lectures alluded to the great importance of diagnosis, but I would especially urge it in these cases. Numerically speaking, cases such as those now before us come under observation more commonly than any other. By far the majority of those cases where inter. ference is required are instances of arrest of the head in the pelvis, and it is during the second stage of labour, when the powers of nature prove inadequate to the task of bringing forth the child, that our diagnostic skill and manual dexterity are most frequently called into requisition. To estimate aright the nature of the impediment present at this time is of the highest importance ; and I presume few will be found to dis. agree with me when I state that the attention which has been bestowed on the diagnosis of these cases has been inadequate to its importance. The element of time has been too exclusively the guide of the obstetric practitioner as a means of estimating the method of treatment to be pursued, and the policy or impolicy of interference; the result being that the patient has not unfrequently been left long unassisted in cases where, from the nature of things, the most liberal allowance of time must have been without avail in procuring the desired end. The true foundation for treatment will be found in an accurate diagnosis of the cause and nature of the arrest. These various causes and eonditions I next proceed to describe. Cause of arrest in the progress of the head least commonly witnessed -Under this category will come the following :-1. Contraction of the outlet of the pelvia. 2. Prolapse of the bladder, over distension of that viscus, or calculus in the bladder. 3. Accumulation of fseoes in the rectum. 4. Tumour in the pelvis, ovarian or otherwise. 5. Cicatrices in the vagina, resulting from injury in previous lab<1urs. 6. Rigidity of the 03 uteri. To these should he added-7. Imperforate condition of the os uteri. And 8. Presence of a thickresisting hymen. These two latter conditions are, however, of extreme rarity. With the exception of the first in the foregoing list-undue contraction of the pelvic outlet,—a,n ordinarily careful examination would at once reve.d the nature of the obstruction present. Causes of arrest more coinjitonly observed.-1. Inefficient action of the uterus, what has been technically termed inertia ute/'i. 2. (Jndue size of the head, or undue hardness of the head to such an extent as to interfere with its moulding and adaptation to the canal through which it has to pass. 3. Narrowness of the pelvis, a condition which is, as I have already remarked, not so extremely rare as has been generally supposed. 4. Rigidity of the soft parts, especially likely to be the cause of arrest in primiparse, and the more so in primipare advanced in life. 5. An abnormal position of the foetal headviz., in the third or fourth positions, facial presentation, and the rare complication of presentation of an arm with the head. The conditions set forth in the foregoing list are by far the most common as leading to arrest in the progress of the labour during its second stage. We may meet with any one of them separately, or in combination with others ; and we may have to deal a ith cases in which the first three, e. g., are associated -viz., uterine inertia, undue size of the head, and a small pelvis, and under these circumstances the difficulty is proportionately increased. How are we to distinguish these several causes of arrest in the progress of the head ? It can only be done by making a most careful examination. Thus if we find that the head readily recedes on pressure, this would militate against the hypothesis that the head was too large for the pelvis, or that the pelvis was too small to allow the passage of the head. If the pains be strong and regular, and there be no advance made, this will render it probable that the arrest is not dependent upon inertia uteri, and the cause must be sought elsewhere. Presence of an unduly ossified head is detected by examination of the fontanelles, which would be found smaller than usual. It is difficult to estimate the absolute size of the head at this stage of the labour; but it is to be remarked that considerable enlargement of the head due to hydrocephalus is rarely observed obstructing labour at this stage, for in cases of hydrocephalus the head does not generally descend into the cavity of the pelvis, but becomes arrested at the brim. Moreover,. the condition of the fontanelles is diagnostic of the latter condition. The third or fourth positions of the head, which generally have the effect of delaying the labour for several hours, should be readily detected by means of examination. The posterior fontanelle will in such cases be found near the sacro-iliac synchondrosis. These are the chief diagnostic fea-tnrfR tn I)P. reliarl nn The term "impaction" has been used as applied to these cases of arrest of the head. Cases of "impaction," using the word in its most extended sense, are of two kinds-1, necessary impaction, which occurs in those cases where the head is large or the pelvis small, or both ; 2, secondary impaction, which is observed where the head has remained a long time in the pelvis, and, by pressing on the soft parts, has caused such an amount of swelling of the soft parts that it becomes impacted. TBATMENT.—At the present moment I shall limit myself to the consideration of the treatment of those cases included in the foregoing enumeration which are of the more ordinary kind, and excluding the cases mentioned under the first category, inasmuch as they require special methods of management. In the first place, it is necessary to remark that our trea' ment will be generally influenced by the decision of the question as to whether the child is alive or dead, and, if alive, by the state of the fcetal pulse as ascertained by auscultation. If the child be found to be certainly dead, the operation of craniotomy is preferable if the impaction or arrest of the head have existed for some hours, or if there be reason to anticipate any difficulty in the use of the forceps ; if, on the other hand, the child be alive, and the fcetal pulse be found either greatly quickened or greatly diminished in frequency (below 100, e. g.), the deducdons are obvious, that in the tirst place craniotomy is to be avoided, if possible, and, in the second place, that by a speedy delivery only can we hope to procure a living child. The value of auscultation as a guide to treatment, quoad the preservation of the life of the child, is certainly not sufficiently recognised. The wider question which I would now discuss concerns those cases in which the child is, so far as can be ascertained, in a state of health at the time the arrest is observed, and at the time when a decision as to the treatment is called for. Looking simply to the possibility of delivery by the natural efforts, it is undoubtedly the fact that there are but very few cases indeed where, the head having become thoroughly engaged in the pelvic cavity, and no markedly abnormal condition of the pelvis being present, natural delivery will not sooner or later occur. Bnt, as I have on a former occasion remarked,* the de. livery of the woman is not our only object. It is little to our credit if the labour be so protracted ("naturally"!) as to sp.rinji,41%, e'tngpr the Drnspfet of the T>lB,tjpIJ,'R recovery it is * See 1EE L,LXCET. MarLh 19lh.lB4.