FIBRINOLYSIS FOLLOWING OPERATION

10

FIBRINOLYSIS FOLLOWING OPERATION BY R. G. SIR

MACFARLANE, M.B. Lond.*

HALLEY

STEWART RESEARCH FELLOW, DEPARTMENT PATHOLOGY, ST. BARTHOLOMEW’S HOSPITAL, LONDON

OF

quantity of blood taken immediately operation for cholecystectomy led by chance to the observation of a curious phenomenon. It had been allowed to clot in a centrifuge tube and was left overnight at 37° C. in order that the serum might be obtained when retraction was complete. The next morning, however, it was found that the blood was quite fluid and all trace of the clot, which had been perfectly firm the evening before, had disappeared. A few days later my attention was called, by Dr. L. P. Garrod, to a recent paper by S. S. Yudin, in which the Russian practice of transfusing with A. after

SMALL

an

blood obtained from corpses was described. In this paper stress was laid upon the fact that persons meeting sudden or violent death were particularly useful donors for a very remarkable reason. If, in these cases, the blood was withdrawn soon after death, it was found that, though coagulation soon took place in the ordinary way, the blood returned to the fluid state in the course of an hour or two, the clots having apparently dissolved. Since it showed no further tendency to coagulate, the addition of anticoagulants was not required, and it could be preserved in this state almost indefinitely, being used for transfusion when needed. In the light of this paper, therefore, the phenomenon first described began to assume a possible significance, particularly since the fibrinolysis observed by the Russians was associated in their minds with the profound shock experienced before death. The question arose as to whether this fibrinolysis occurred, possibly in a lesser degree, in living persons who had suffered accidental trauma, or undergone surgical operation. Though this problem is at present more of academic interest than of clinical importance it The present paper is was decided to investigate it. a report of the admittedly incomplete and elementary experiments with which this investigation has been

begun. EXPERIMENTS

Patients undergoing surgical operation were selected being the best subjects to begin with, since blood and could be obtained immediately before, control accurate the and trauma, immediately after, therefore obtained. The anaesthetie, of course, introduced a variable factor, but by choosing a series of cases which included the use of inhalation, spinal, and local anaesthesia, it was felt that the effects of these could be determined and as

eliminated. At first, attempts were made to repeat the original observation. Blood was obtained by venipuncture before and after operation in about 20 cases, and allowed to clot in centrifuge tubes. These tubes were then incubated at 37° C. and the contents examined in twenty-four hours. In 2 cases complete lysis had occurred at the end of this time in the postoperative blood. In one of these the blood was from a woman who had an operation for cholecystectomy ; in the other it was from a woman who had a needle removed from her hand under a local

anaesthetic. *

Assisted by

Council.

an

expenses grant from the Medical Research

In a large proportion of the remaining cases the post-operative clots appeared to be more friable than those obtained from the pre-operative blood, though there was no definite evidence of lysis. The method appeared to be unsatisfactory, since the turbidity of the fluid made it impossible to see the state of the clot without interfering with it. It was therefore decided to experiment with recalcified citrated plasma. Blood was obtained before and after operation as in the previous series, but was immediately citrated by the addition of one-tenth of its volume of 3-8 per cent. sodium citrate solution. It was then centrifuged at slow speed for ten minutes by the clock, and the plasma removed by pipette. Of this, 4 c.cm. was recalcified in each case by the addition of 1 c.cm. of 1.18 per cent. calcium chloride solution, and the tubes containing the clots incubated for twenty-four hours at 37° C. as before. In 2 cases out of 22 examined in this way complete lysis occurred during the period of incubation, one being after nephrectomy, and the other after excision of an epithelioma on the back. Both patients were males and both had general nitrous oxide oxygen and ether anaesthesia. The remaining 20 cases again showed indefinite signs of lysis ; in the majority the post-operative clots were more fragile (in some cases actually fragmented), and the serum more turbid than was the case with the pre-operative controls. The results, however, were inconclusive, and a method of measuring the exact degree of lysis after a definite period of incubation was required. Attempts were made to weigh the clots, after washing and drying, and thus determine the extent of lysis, if any. This project proved to be unsuccessful. It was found impossible to free the close-textured plasma clots from adsorbed serum proteins to a satisfactory degree, and inconsistent results were obtained. It was an attempt to overcome this difficulty that led to the production of what appears to be a delicate and satisfactory method of demonstrating fibrinolysis. In order to reduce the adsorption of serum proteins on to the fibrin that was to be weighed, a method commonly used in the estimation of blood fibrinogen was employed. If 1 c.cm. of citrated plasma be added to 1 c.cm. of 1’18 per cent. calcium chloride solution and 28 c.cm. of 0.85 per cent. saline, subsequent coagulation results in the formation of a fine fibrin reticulum throughout the whole volume of the fluid. This web can be wound on to a glass rod, washed in distilled water, and its mass estimated directly by drying and weighing, or from its nitrogen content by the micro-Kjeldahl apparatus. It was proposed to prepare two such webs from pre-operative, and two from post-operative, blood, one of each of these to be estimated immediately, and the other two after 24 hours’ incubation. Accordingly blood was obtained from a man about to undergo an operation for the cure of an inguinal hernia, under a local anaesthetic. It was at once citrated, and the plasma obtained as before. The fibrin webs were prepared in the way described in two boiling tubes, one of which was incubated. The other was used immediately to estimate the blood fibrinogen, by the gravimetric method. The whole process was then repeated with blood obtained as the patient was leaving the theatre, the technique being rigidly adhered to. The pre-operative and post-operative blood fibrinogens were found to be 320 and 310 mg. per 100 c.cm. respectively. The pre-operative and post-operative fibrin webs remaining were left until the next morning

11 at 37° C., when it was proposed to estimate their mass in the same way. The next morning, however, it was found that this procedure could not be carried out. The pre-operative web was intact, giving an - equivalent of 310 mg. per 100 c.cm., but the postoperative web had completely disappeared, leaving a clear fluid. Similar results were obtained with two cases of partial thyroidectomy, the pre-operative clots remaining intact and the post-operative fibrin dissolving in less than 24 hours.

The

Effect of Operation

on

Fibrinolysis

then obtained from a series of operation cases, which In every case blood was tabulated above. obtained within one hour of the operation, and usually as the patient was leaving the theatre. The pre-operative blood was obtained the day before, or before premedication was given in all except 3 cases, when it was taken just before the anaesthetic was administered. From the accompanying Table and the 3 cases described previously it will be seen that in 22 cases out of a total of 29 complete lysis of post-operative clots occurred in twenty-four hours. Of the remaining 7, 2 showed increased lysis as compared with the controls, and 5 showed none during the period of incubation employed. Experiments were then performed to ascertain, if possible, the nature of the lysis. It appeared to be a physical rather than a chemical change, though this has not yet been confirmed. The first stage is one of fragmentation of the clot, which proceeds until dispersion is complete. The fluid remaining is quite clear by ordinary transmitted light but the Tyndall beam is brighter after lysis than before. After standing for several days at room temperature, the fluid containing lysed fibrin deposits a light are

precipitate, shaking.

which

redisperses

on

warming

or

showing post-operative lysis the following performed. As soon as the fibrin webs had formed they were removed from the fluid, washed in two changes of saline, and placed in each In 4

cases

experiment

was

other’s fluid. The results obtained were the same in each experiment and are summarised below :-

G.

=

gas.

0.

=

oxygen.

E.

=

ether.

d.

=

days.

At this stage blood was obtained from 6 normal - donors, and fibrin prepared in the same way. In these, incubation was carried on for longer periods to observe the changes that were likely to occur in normal fibrin under these conditions. In one of these there was evidence of some lysis after 48 hours, -since the web broke up into fragments on gently shaking the tube, the other 5 being unaffected by similar treatment. These fragments, however, did not dissolve until two days later. By the fifth day one other tube showed the same change, but the other 4 were unaffected, and when two days later the experiment was discontinued, these were still In 4 out of 6 therefore lysis did not occur intact. in seven days, in one partial lysis took place in two days and complete lysis in four days, and in the remaining one, partial lysis had begun by the fifth day but was not complete on the seventh. Blood was

These results suggest that the lysis therefore is due to some change in the fibrin, or some substance adsorbed by it from the serum, rather than the preTo differentiate between these sence of a free lysin. alternatives, the following experiment was performed. Pre-operative and post-operative fibrin, washed in saline as before, was added to post-operative and preoperative plasma, in a concentration of 1 in 30 in saline, with the addition of a few drops of sodium citrate solution, to prevent possible coagulation by any calcium remaining in the fibrin. The results were as follows :

These results suggest that the lysis is due to a change integral with the structure of the fibrin itself. In all these experiments, of course, sterile apparatus and solutions were used and aseptic technique adopted. Cultures taken from the contents of tubes after incubation have remained sterile in the cases

reported.

12 CONCLUSION

The position therefore is as follows. Some change in the fibrin structure occurs as a result of trauma, which, under strictly aseptic conditions, results in the dispersion of the fibrin reticulum. This change has been observed under the conditions described in 24 out of 29 operation cases, obviously too small a series to be conclusive, but large enough to be suggestive. Bacteria do not appear to play a part, since cultures of the fluid containing lysed fibrin are sterile. Whether this rapid lysis ia merely an acceleration of the normal aseptic lysis, which is regarded by Nolf as the natural sequel to coagulation, remains to be seen. Future work will be directed towards the confirmation of its occurrence as described, and to a possible elucidation of its mechanism and

examination of the contour of the chest wall is very helpful. The method I use is to outline the contour of the chest wall on an X ray film and to transpose it on a sheet of paper. If the radiogram has been taken correctly, the outline of the chest will be clearly visible on the film, the edge of the ribs contrasting quite sharply against the shadow of less density given by soft parts covering the thorax.

TABLE I

Ages of

82 Asthmatic Patients

showing

Chest

Deformity

significance. My thanks are due to Prof. Geoffrey Hadfield and Prof. Paterson Ross for their interest and advice, and to those members of the surgical staff of St. Bartholomew’s Hospital who have given permission for these investigations to be carried out on their cases. REFERENCES

Nolf, P. (1908) Arch. int. Physiol. 6, 306. Yudin, S. S. (1936) Pr. méd. 44, 68.

CHEST DEFORMITIES IN ASTHMA BY H. H.

MOLL, M.D. Rome, M.B. Leeds, M.R.C.P. Lond.

ASSISTANT PHYSICIAN TO THE GENERAL INFIRMARY AT PHYSICIAN TO THE LEEDS PUBLIC DISPENSARY AND HOSPITAL

WHEN asthma is of

nearly always present.

LEEDS

long standing emphysema is The distension is the sequel than an organic disorder of

of a functional rather the lung, and with abatement of the attacks of asthma the lungs gradually empty themselves and return to their original size. With recurrent and protracted attacks, however, the approximation to normal is less complete after each attack, and the chest wall In well-established becomes distended and fixed. cases the shoulders are lifted and the back is hunched. The sternum bulges prominently and may form a typical pigeon breast. The chest is rounded in its upper half, there is a deep lateral sulcus, and the base is narrow and contracted. The appearance of the chest is that of an inverted flask. This deformity is quite different from the " barrel chest " usually associated with genuine hypertrophic emphysema. In the barrel chest the upper part of the thorax is not unduly expanded, the widening of the chest increases progressively from above downwards, and reaches its maximum at the base. Dorsal kyphosis and anterior pigeon deformity are not prominent features. Chest deformities of long-standing asthma are easily detected even with the patient fully clothed. Not every asthmatic, however, presents the same degree of chest deformity, and the deformity varies with each type of individual in its time of onset as well as in its rapidity and extent of development. The stature of the asthmatic sufferer is an important factor, the thin type showing chest abnormalities more readily than the obese type. Moreover, in obese subjects and in women with large breasts deformities of the chest wall are difficult to detect by inspection alone, since soft parts may completely mask the deformity. In such cases radiological

A radiological study of chest deformities has been made in a series of 128 consecutive and unselected cases of asthma attending the asthma clinic at the Leeds General Infirmary. This paper does not deal with the more usual radiological signs of emphysema, such as localised brilliancy of the lung fields, increased density of the hilum shadows, and limitation of movements of the diaphragm. From a recent discussion1 it appears that radiologists now agree that the radiological diagnosis of emphysema must never be based on one sign alone but always on a combination. One of the speakers, Dr. Kerley, gave a timely warning that the so-called increased translucency of the lungs may be due to factors which have nothing to do with the lungs. Thus it can be produced by over-exposure or over-penetration, and it is also seen under normal technical conditions in thin subjects. This is a point of some importance, for undue reliance on this very misleading radiological sign probably leads to the diagnosis of emphysema being made more often than is justified. TABLE II Duration

of Illness

in 61 Cases

showing

Chest

Deformity

It is somewhat surprising that in the radiological of emphysema more attention is not paid to the appearances of the bony framework, for distension of the lungs must inevitably bring about deformity of the chest wall, and the degree of the deformity is therefore a good exponent of the amount of over-stretching which has taken place in the

diagnosis

lungs. In early cases the most noticeable change is a " ladder " appearance of the contour of the chest. Normally the ribs, which run obliquely from above downwards and forwards, overlap each other in a. regular fashion, and with their outer surface form an even outline of the thoracic wall (Fig. 1). As the become become the ribs raised over-expanded lungs and approach the horizontal position, normal overlapping does not occur, the outer surfaces of the ribs fail to form an even contour, and the outline of the chest becomes irregular (Figs. 2 and 6). This type of chest is often observed in asthmatic children and in