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TREATMENT OF DEEP-VEIN THROMBOSIS
777
Letters to the Editor TREATMENT OF DEEP-VEIN THROMBOSIS SiR,-It is sad to see you devoting so much of your valuable space to a long, complicated, and involved leader which can only serve to keep the treatment of this condition hidden in the well-nigh impenetrable fog which appears to surround it at the moment. I suppose one of the main reasons why I feel sad is the realisation that your leader is written without any knowledge of the mechanism of venous return from the legs-which surely is the whole nub of the successful treatment of this condition. How else could you possibly print the amazing statement: "Why early movement and ambulation do not precipitate clinical embolism is difficult to explain." The reason why early movement and ambulation are safe is because the increased venous return up the leg literally seals off the foci of clot and prevents it spreading any further. We must get it into our heads that it is sluggish blood-flow which precipitates thrombosis. By the same token, the reason why " early ambulation ", as practised in the past, has had no effect on the incidence of postoperative deep-vein thrombosis is because the patients were not ambulated at all. All that happened was that these patients were got up out of bed on the first or second day and thrown into a chair where they sat huddled up not moving their legs at all. Even if they walked, they shuffled in slippers, did not move their ankles, and had no venous return worth speaking of. They would probably have been safer if left in bed, but this was enough for the ward sister to be able to enter in the records " Patient up
today" ! The prevention of deep-vein thrombosis is so simple that it eludes the active brain of the scientist and the keen eye of the academic clinician, both of whom feel that there must be some very complicated answer. All we have to do to abolish deepvein thrombosis from our wards is to raise the foot of every patient’s bed 9 in. and to teach them to do simple flexion and extension exercises of the ankles from the moment they enter the hospital. We do not need a physiotherapist to show them this. Nurse can show them just as well, and she is at hand to encourage them during the first one or two days, after which it becomes a habit. Beds should have a simple form of cradle incorporated in them to keep the bed-clothes off the feet and thus render movement easy. This is all we need. To subject our patients to prophylactic anticoagulants may make us feel terribly clever, may help to maintain the cost of the National Health Service, may justify an increase in the salary of patho-
logical technicians, and may even give rise to some interesting hxmatological emergencies, but so far as treating the patients is concerned, it is dangerous clinical claptrap. Flexion and extension at the ankle contracts the calf muscles and maintains venous blood-flow at its normal ambulatory rate. With the foot of the bed raised 9 in. and the patient using one pillow only for sleeping, the heart is below the level of the legs and venous return is maintained when the patient is dozing. Thus, the blood-flow never slows down and the blood will not clot. I suppose the only danger of this treatment is that deep-vein thrombosis will be such a rare occurrence that when it does happen we shall have forgotten how to deal with it. But here again, the simplest plan is by far the best. Put your patients with deep-vein thrombosis to bed, give them one pillow only for their heads, raise the foot of the bed 9 in., and start them doing ankle exercises immediately. Do not allow them to sit up in bed at all except to eat their meals and then push them straight down. Start them on the simple heparin scheme outlined by Bauer1 in 1946 (a wonderful contribution to the treatment of venous diseases, in contrast to his disastrous 1. Bauer, G. Lancet, 1946, i, 447.
suggestion of femoral and popliteal ligation for the established post-thrombotic leg). Within 48 hours, all the oedema will have disappeared and the patients may be allowed up on graduated walking (i.e., 5 minutes every 2 hours), while the dosage scheme continues for a further 4 or 5 days. London, W.I.
STANLEY RIVLIN.
’*’ ’*’ We agree that proper movements and ambulation may alone do much to prevent the spread of existing thrombi, but unfortunately thrombus detachment and embolism may be precipitated. This was the well-known dilemma before the coming of anticoagulants. Anticoagulants, on the other hand, not only prevent further thrombosis but also inhibit clinical embolism in most cases, even when movement is permitted; and the reason for this, as we remarked, is hard to understand. Dr. Rivlin himself does not rely entirely on exercises and leg-raising in treating thrombosis: he also uses an anticoagulant (heparin)-for rather too short a period in our view. In our leader of Sept. 22 we were not primarily concerned with the aetiology of thrombosis or its prevention ; and we had earlier given our views1 on venous stasis and thrombosis. The policy of anticoagulant prophylaxis has, in fact, arisen partly out of the failure of movement and ambulation to prevent thrombosis and embolism. But, in support of Dr. Rivlin’s plea for early prophylactic exercises was the work of Hunter and his colleagues,2 who found deep-vein thrombosis at necropsy in 18% of patients given exercises, compared with 53% among concurrent patients who were not up and about and who had no exercises. On the other hand, many surgeons have been disappointed with early postoperative rising and prophylactic exercises,3-5 which did not seem to influence the annual rate of clinical thrombosis or embolism. Perhaps a controlled clinical trial of prophylactic exercises versus anticoagulants would help to settle the question of prevention. In many patients, such as those with fractured legs, effective exercises will not be possible and anticoagulants will be required.-ED. L. THE PSYCHOPHYSICS OF CLINICAL PAIN
SIR,-Dr. Lasagna (Sept. 22), discussing the reality
or
otherwise of the correlations he observes between initial pain scores and the relief of pain by analgesics and placebos, refers to my forthcoming paper in which I suggest that the best way to eliminate the spurious element in such correlations is by plotting the change of score
(i—:) against the mean of the initial and final scores 1/2(Xl +--x2). He comments that it is unclear what biological meaning this latter function has, and suggests that lack of correlation between it and the change of score does not rule out a real " relation between initial level and change "
of level. I do not think it is impossible to give a biological meaning to the comparison I propose. The change of score is a measure of the average at which, in Dr. Lasagna’s case, pain is being relieved. We do not know how this rate varies throughout the period of the experiment. It may be constant, or it may be that initially the rate of relief of pain is high but steadily diminishing, or it may be that the rate of relief is initially low and steadily increasing. Only 1. Lancet, 1961, i, 264. 2. Hunter, W. E., Krygier, J. J., Kennedy, W. J. C., Sneeden, V. D. Surgery, 1945, 17, 178. 3. Blodgett, J. B., Beattie, E. J. Surg. Gynec. Obstet. 1946, 82, 485. 4. Powers, J. H. Arch. Surg. 1949, 59, 601. 5. McCann, J. C. New Engl. J. Med. 1950, 242, 203.
Letters to the Editor TREATMENT OF DEEP-VEIN THROMBOSIS SiR,-It is sad to see you devoting so much of your valuable space to a long, complicated, and involved leader which can only serve to keep the treatment of this condition hidden in the well-nigh impenetrable fog which appears to surround it at the moment. I suppose one of the main reasons why I feel sad is the realisation that your leader is written without any knowledge of the mechanism of venous return from the legs-which surely is the whole nub of the successful treatment of this condition. How else could you possibly print the amazing statement: "Why early movement and ambulation do not precipitate clinical embolism is difficult to explain." The reason why early movement and ambulation are safe is because the increased venous return up the leg literally seals off the foci of clot and prevents it spreading any further. We must get it into our heads that it is sluggish blood-flow which precipitates thrombosis. By the same token, the reason why " early ambulation ", as practised in the past, has had no effect on the incidence of postoperative deep-vein thrombosis is because the patients were not ambulated at all. All that happened was that these patients were got up out of bed on the first or second day and thrown into a chair where they sat huddled up not moving their legs at all. Even if they walked, they shuffled in slippers, did not move their ankles, and had no venous return worth speaking of. They would probably have been safer if left in bed, but this was enough for the ward sister to be able to enter in the records " Patient up
today" ! The prevention of deep-vein thrombosis is so simple that it eludes the active brain of the scientist and the keen eye of the academic clinician, both of whom feel that there must be some very complicated answer. All we have to do to abolish deepvein thrombosis from our wards is to raise the foot of every patient’s bed 9 in. and to teach them to do simple flexion and extension exercises of the ankles from the moment they enter the hospital. We do not need a physiotherapist to show them this. Nurse can show them just as well, and she is at hand to encourage them during the first one or two days, after which it becomes a habit. Beds should have a simple form of cradle incorporated in them to keep the bed-clothes off the feet and thus render movement easy. This is all we need. To subject our patients to prophylactic anticoagulants may make us feel terribly clever, may help to maintain the cost of the National Health Service, may justify an increase in the salary of patho-
logical technicians, and may even give rise to some interesting hxmatological emergencies, but so far as treating the patients is concerned, it is dangerous clinical claptrap. Flexion and extension at the ankle contracts the calf muscles and maintains venous blood-flow at its normal ambulatory rate. With the foot of the bed raised 9 in. and the patient using one pillow only for sleeping, the heart is below the level of the legs and venous return is maintained when the patient is dozing. Thus, the blood-flow never slows down and the blood will not clot. I suppose the only danger of this treatment is that deep-vein thrombosis will be such a rare occurrence that when it does happen we shall have forgotten how to deal with it. But here again, the simplest plan is by far the best. Put your patients with deep-vein thrombosis to bed, give them one pillow only for their heads, raise the foot of the bed 9 in., and start them doing ankle exercises immediately. Do not allow them to sit up in bed at all except to eat their meals and then push them straight down. Start them on the simple heparin scheme outlined by Bauer1 in 1946 (a wonderful contribution to the treatment of venous diseases, in contrast to his disastrous 1. Bauer, G. Lancet, 1946, i, 447.
suggestion of femoral and popliteal ligation for the established post-thrombotic leg). Within 48 hours, all the oedema will have disappeared and the patients may be allowed up on graduated walking (i.e., 5 minutes every 2 hours), while the dosage scheme continues for a further 4 or 5 days. London, W.I.
STANLEY RIVLIN.
’*’ ’*’ We agree that proper movements and ambulation may alone do much to prevent the spread of existing thrombi, but unfortunately thrombus detachment and embolism may be precipitated. This was the well-known dilemma before the coming of anticoagulants. Anticoagulants, on the other hand, not only prevent further thrombosis but also inhibit clinical embolism in most cases, even when movement is permitted; and the reason for this, as we remarked, is hard to understand. Dr. Rivlin himself does not rely entirely on exercises and leg-raising in treating thrombosis: he also uses an anticoagulant (heparin)-for rather too short a period in our view. In our leader of Sept. 22 we were not primarily concerned with the aetiology of thrombosis or its prevention ; and we had earlier given our views1 on venous stasis and thrombosis. The policy of anticoagulant prophylaxis has, in fact, arisen partly out of the failure of movement and ambulation to prevent thrombosis and embolism. But, in support of Dr. Rivlin’s plea for early prophylactic exercises was the work of Hunter and his colleagues,2 who found deep-vein thrombosis at necropsy in 18% of patients given exercises, compared with 53% among concurrent patients who were not up and about and who had no exercises. On the other hand, many surgeons have been disappointed with early postoperative rising and prophylactic exercises,3-5 which did not seem to influence the annual rate of clinical thrombosis or embolism. Perhaps a controlled clinical trial of prophylactic exercises versus anticoagulants would help to settle the question of prevention. In many patients, such as those with fractured legs, effective exercises will not be possible and anticoagulants will be required.-ED. L. THE PSYCHOPHYSICS OF CLINICAL PAIN
SIR,-Dr. Lasagna (Sept. 22), discussing the reality
or
otherwise of the correlations he observes between initial pain scores and the relief of pain by analgesics and placebos, refers to my forthcoming paper in which I suggest that the best way to eliminate the spurious element in such correlations is by plotting the change of score
(i—:) against the mean of the initial and final scores 1/2(Xl +--x2). He comments that it is unclear what biological meaning this latter function has, and suggests that lack of correlation between it and the change of score does not rule out a real " relation between initial level and change "
of level. I do not think it is impossible to give a biological meaning to the comparison I propose. The change of score is a measure of the average at which, in Dr. Lasagna’s case, pain is being relieved. We do not know how this rate varies throughout the period of the experiment. It may be constant, or it may be that initially the rate of relief of pain is high but steadily diminishing, or it may be that the rate of relief is initially low and steadily increasing. Only 1. Lancet, 1961, i, 264. 2. Hunter, W. E., Krygier, J. J., Kennedy, W. J. C., Sneeden, V. D. Surgery, 1945, 17, 178. 3. Blodgett, J. B., Beattie, E. J. Surg. Gynec. Obstet. 1946, 82, 485. 4. Powers, J. H. Arch. Surg. 1949, 59, 601. 5. McCann, J. C. New Engl. J. Med. 1950, 242, 203.