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MANAGEMENT, DURING DENTAL SURGERY, OF PATIENTS ON ANTICOAGULANTS
99
Special Articles
dentist with the opportunity of observing the reaction to dental surgery in a substantial number of patients on this
therapy.
MANAGEMENT, DURING DENTAL SURGERY, OF PATIENTS ON ANTICOAGULANTS H. MCINTYRE M.D., B.D.S. Manc., F.D.S. SENIOR LECTURER IN CLINICAL DENTISTRY, UNIVERSITY AND ROYAL INFIRMARY, MANCHESTER 13
VASCULAR degenerative diseases complicated by thrombosis are becoming increasingly common. The sites for such a catastrophe are the coronary arteries and the middle cerebral arteries of the brain. To counter this tendency to thrombosis, drugs which have a powerful anticoagulant action are used. Most people taking these drugs do so as a
prophylactic
measure
against
recurrent
myocardial
infarction. Less commonly the dental surgeon encounters a patient with rheumatic heart-disease (usually mitral stenosis with auricular fibrillation) where thrombi may form in the heart itself and be disseminated as emboli throughout the body. To prevent this, anticoagulant therapy is instituted. Occasionally, patients with venous thrombosis affecting the legs are found to be taking anticoagulant drugs. Since hxmorrhage is the main danger associated with the use of this therapy, the problem posed by these patients is similar to that of the hsemophiliac as regards dental management, although the bleedingtendency can be controlled more easily.
Coronary-artery disease is already frequent and it has been suggested that as the stress and strains of everyday life increase, the incidence of this disease will also rise. Patients on anticoagulant drugs require routine tests to maintain a therapeutic level of blood coagulation in order to obviate spontaneous haemorrhages. The well-supervised patient is unlikely to suffer a severe haemorrhage, but minor bleeding episodes, manifested by epistaxis, bruising of the skin and bleeding from the gums, occur in about 40% of patients on treatment (British Medical Journal 1963). Anticoagulant drugs can be divided into the direct anticoagulants (e.g., heparin) and the indirect anticoagulants, the coumarins and indanediones. Heparin delays the thrombin-fibrinogen reaction and prevents the formation of thrombin from prothrombin. The indirect anticoagulants, being synthetic substances must be absorbed and metabolised by the body. They interfere with the formation of four of the coagulation factors: factors n, vii, ix, and xi. The action of these drugs can be reversed in a matter of hours by the use of vitamin K. Control of anticoagulant therapy has been based for years on the one-stage prothrombin-time (Quick 1935). Drug dosage is so adjusted that prothrombin-times of 11/2-2’/2 maintained in what is called a " therapeutic range ". The therapeutic range is about 15-30% of normal if a saline extract of acetone-dried rabbit or human brain is used as a thromboplastin reagent in the test. Owren (1959) in his’Thrombotest’ method has modified the one-stage technique and produced a method capable of measuring " extrinsic " blood-thromboplastin factors besides prothrombin and factor vii. The therapeutic range of the thrombotest is 7-15% of normal. Patients on anticoagulant therapy attend hospital at regular intervals for estimation of the prothrombin-time and naturally a great many are referred to the dental department for treatment, thus providing the hospital
times normal
are
Conservation of teeth is always preferable to extraction; and in the patient with coronary-artery disease this is even more important. Wherever possible, teeth should be filled even although local anaesthesia is required for the preparation of large cavities. It is essential that anxiety and stress are reduced to a minimum and so the alleviation of pain during and after dental surgery has to be
considered carefully. MANAGEMENT
Anaesthesia General anaesthesia in the cardiac patient is undertaken only in the apprehensive patient and then only after an examination by an anxsthetist who will decide if admission to hospital is advisable. For a local anaesthetic a 2% solution of ’Lignocaine ’ with adrenaline 1:80,000 is highly satisfactory. The use of adrenaline in patients with coronary-artery disease may be questioned because of the risk of vasoconstriction but in my experience there have been no untoward effects. The infliction of pain because the local anaesthetic has worn off too soon may just as easily produce vasoconstriction and precipitate coronaryartery occlusion. As a rule dental extractions should not be carried out within three months of a coronary thrombosis. Antibiotics Patients with rheumatic heart-disease require antibiotic cover for dental extractions since the bacteraemia after such surgery may predispose to subacute bacterial endocarditis. 500,000 units crystalline penicillin and 300,000 units procaine penicillin administered together half an hour preoperatively give adequate protection. Patients with myocardial infarction have no need of prophylactic antibiotics.
.Hoemorrhage The main
danger associated with the taking of anticoagulant drugs is haemorrhage and dental extraction to be properly managed under such circumstances demands close cooperation between the clinical pathologist and the dental surgeon. Opinions differ as to management. Some prefer to reduce the dose of anticoagulant sufficiently to allow the prothrombin-time to return to 50% of normal for at least 48 hours, to cover the period of extractions and the immediate postoperative period (Spouge 1964). Others recommend the withdrawal of anticoagulant drugs for 2 days before dental surgery with resumption the following day. Poller and Thompson (1964), investigating the effect of abrupt withdrawal of anticoagulants, found evidence of a rebound hypercoagulability in the blood with increased risk of thrombosis. Others prefer to operate when the prothrombin-time is in the upper level of a therapeutic range. SURVEY
To assess the results of dental extraction 106 patients (13 inpatients) taking anticoagulant drugs were operated upon with the prothrombin-time adjusted to the therapeutic range of 7-15%thrombotest. This group was comprised of 76 people with myocardial ischaemia, 11 angina pectoris, 7 pulmonary embolism, 8 rheumatic heart-disease, and 4 venous thrombosis. This group was then compared with the same number of patients with
100 normal blood coagulation. In both groups the age incidence was the same. For ease of description patients on anticoagulant treatment were called group A while group B was comprised of those with normal
coagulation.
unnecessary. On average, 6 teeth extracted at any one time from patients taking anticoagulant drugs, but more radical treatment can be undertaken if indicated.
operative ice-packs is
were
I thank Dr. M. C. G. Israels for his advice and Dr. J. McIver and Dr. A. Turner of the department of clinical pathology, Manchester
Methods
Royal Infirmary.
administered as phenindione, Anticoagulant therapy or nicoumalone. The patients attended the phenprocoumon, clinic two before anticoagulant days operation so that the prothrombin-time could be adjusted to the upper level of the therapeutic range using the thrombotest as described by Owren (1959). The prothrombin-time was rechecked on the day of operation and the patient advised to delay the daily dose of was
until the evening. Local anaesthesia was used in all except 4 patients in group A and 18 patients in group B. Of the 4 who had general anaesthesia one patient, with rheumatic heart-disease, had 21 teeth extracted in a single operation. Where indicated antibiotic cover was given as already described. With the exception of 12 patients in group A who required surgical extractions, both groups were treated by routine dental procedures. Only 13 in group A were treated as inpatients. After operation the sockets were digitally compressed and the patient requested to bite on a gauze pad for approximately 30 minutes to arrest hsemorrhage. The patient, if an outpatient, was then allowed to leave. They attended the outpatient clinic on the 3rd day for prothrombin estimations and thereafter every 4-6 weeks for as long as was considered necessary by the clinician responsible for the drug therapy.
REFERENCES
British Medical Journal (1963) i, 801. Owren, P. A. (1959) Lancet, ii, 774. Poller, L., Thompson, J. M. (1964) Manchester med. Gaz. 3, 8. Quick, A. J. (1935) J. biol. Chem, 109, 73. Spouge, J. D. (1964) Oral Surg. 18, 70.
anticoagulant
Complications In both groups there was only one complication. This patient in group A whose thrombotest at the time of operation was 5%. He continued to bleed for 12 hours after the removal of 9 teeth. This bleeding was controlled by the administration of vitamin Kl. was a
DISCUSSION
the behaviour of the two groups in their dental extractions, it was found that, when the patients in group A had the prothrombin-time adjusted to the upper level of the therapeutic range, the postoperative bleeding was no greater than in the normal patient. It was also concluded that most patients on anticoagulant therapy were suitable for outpatient management, that routine dental measures were admissible in those who were not already inpatients, and that recourse to local haemostasis, sutures, and postoperative ice-packs was unnecessary. On average, up to 6 teeth were extracted at any one time from patients in group A.
Comparing
response to
Teeth extracted 1-6
Patients
on
Normal
anticoagulants
patients
89 12 5
46 45 15
7-12
12
but more radical treatment could be carried indicated in the patient on anticoagulant therapy.
out
if
SUMMARY
carried out on 106 patients taking anticoagulant drugs with the prothrombin-time adjusted to a therapeutic range of 7-15% thrombotest (Owren 1959) and the results compared with similar extractions in a control group of the same number. Local anaesthetic was used in all except 4 patients in the anticoagulant group. Most patients may be treated as outpatients, routine measures are permissible in outpatients, and the recourse to local haemostasis, sutures, and postDental extractions
were
Public Health A PIONEER IN THE BALKANS
PORTRAITS, busts, eponymous institutions, lectureships, fellowships, collected papers-these are some of the ways in which great doctors may be honoured. The Andrija Stampar School of Public Health already stands in Zagreb and contains his bust; now comes an English edition of his selected papers.’ Stampar was not a very great thinker or writer, and in any many of the papers suffer somewhat from translation from Serbo-Croat. But he was a man well ahead of his time, with a single, important idea, for which he fought ably, courageously, and singlemindedly throughout his life. He believed that medicine was primarily neither an art nor a science applied to the individual, but a social function which should be freely available to all. In 1911, while still a medical student in Vienna, he set out the views on social medicine which are now reprinted; he lived to see them embodied in the preamble to the constitution of the World Health Organisation, of which he was the first president. case
He had inherited from his father, a village schoolmaster, both his sympathy with the hardships of peasant life and his gift of clear exposition, and he wrote over 70 articles and pamphlets before he was qualified, chiefly on what we should now call " health education ". A contemporary of his schooldays remembers him as quite different from other schoolboys. He was self-reliant, non-conformist and reluctant to yield to the demands of his environment". Early conviction of the evils of alcoholism, for instance, led to lifelong teetotalism. He naturally had a special interest in the " social " diseases and, as a district health officer in Croatia, he also dealt with outbreaks of cholera and smallpox. After the 1914-18 war, he became health adviser to the Croatian Commission for Social Welfare and, at the astonishing age of 31, when still relatively unknown, he was selected for the post of what we should call chief medical officer to the new kingdom of Yugoslavia. The young State had been formed out of the most heterogeneous territories, which had been impoverished by the Balkan wars and the 1914-18 war. Social diseases, such as endemic malaria, syphilis, typhus, trachoma, tuberculosis, were rife and the infant-mortality rate, which was everywhere high, in some places reached the figure of 500 per 1000. What Stampar achieved is set out in two papers in this collection-Five Years of Socio-Medical Work in the Kingdom of Serbs, Croats and Slovenes and Ten Years’ Work on the Promotion of Public Health. At this time he edited and largely wrote two volumes on social medicine as a textbook for the Zagreb Institute, the foundation of which he had inspired. He was now becoming known internationally as a member of the committee of the Health Organisation of the League of Nations. "
By 1930, his left-wing views and the opposition of private
practitioners 1.
had
brought
him into conflict with
powerful
Serving the Cause of Public Health. Selected Papers of Andrya Stampar. Editor: M. D. GRMEK, translated by M. HALAR, revised by L. F. WARING. Obtainable from the Andrija Stampar School of Public Health, Rockefeller St. 4, Zagreb, Yugoslavia. 1966. Pp 258. 87
Special Articles
dentist with the opportunity of observing the reaction to dental surgery in a substantial number of patients on this
therapy.
MANAGEMENT, DURING DENTAL SURGERY, OF PATIENTS ON ANTICOAGULANTS H. MCINTYRE M.D., B.D.S. Manc., F.D.S. SENIOR LECTURER IN CLINICAL DENTISTRY, UNIVERSITY AND ROYAL INFIRMARY, MANCHESTER 13
VASCULAR degenerative diseases complicated by thrombosis are becoming increasingly common. The sites for such a catastrophe are the coronary arteries and the middle cerebral arteries of the brain. To counter this tendency to thrombosis, drugs which have a powerful anticoagulant action are used. Most people taking these drugs do so as a
prophylactic
measure
against
recurrent
myocardial
infarction. Less commonly the dental surgeon encounters a patient with rheumatic heart-disease (usually mitral stenosis with auricular fibrillation) where thrombi may form in the heart itself and be disseminated as emboli throughout the body. To prevent this, anticoagulant therapy is instituted. Occasionally, patients with venous thrombosis affecting the legs are found to be taking anticoagulant drugs. Since hxmorrhage is the main danger associated with the use of this therapy, the problem posed by these patients is similar to that of the hsemophiliac as regards dental management, although the bleedingtendency can be controlled more easily.
Coronary-artery disease is already frequent and it has been suggested that as the stress and strains of everyday life increase, the incidence of this disease will also rise. Patients on anticoagulant drugs require routine tests to maintain a therapeutic level of blood coagulation in order to obviate spontaneous haemorrhages. The well-supervised patient is unlikely to suffer a severe haemorrhage, but minor bleeding episodes, manifested by epistaxis, bruising of the skin and bleeding from the gums, occur in about 40% of patients on treatment (British Medical Journal 1963). Anticoagulant drugs can be divided into the direct anticoagulants (e.g., heparin) and the indirect anticoagulants, the coumarins and indanediones. Heparin delays the thrombin-fibrinogen reaction and prevents the formation of thrombin from prothrombin. The indirect anticoagulants, being synthetic substances must be absorbed and metabolised by the body. They interfere with the formation of four of the coagulation factors: factors n, vii, ix, and xi. The action of these drugs can be reversed in a matter of hours by the use of vitamin K. Control of anticoagulant therapy has been based for years on the one-stage prothrombin-time (Quick 1935). Drug dosage is so adjusted that prothrombin-times of 11/2-2’/2 maintained in what is called a " therapeutic range ". The therapeutic range is about 15-30% of normal if a saline extract of acetone-dried rabbit or human brain is used as a thromboplastin reagent in the test. Owren (1959) in his’Thrombotest’ method has modified the one-stage technique and produced a method capable of measuring " extrinsic " blood-thromboplastin factors besides prothrombin and factor vii. The therapeutic range of the thrombotest is 7-15% of normal. Patients on anticoagulant therapy attend hospital at regular intervals for estimation of the prothrombin-time and naturally a great many are referred to the dental department for treatment, thus providing the hospital
times normal
are
Conservation of teeth is always preferable to extraction; and in the patient with coronary-artery disease this is even more important. Wherever possible, teeth should be filled even although local anaesthesia is required for the preparation of large cavities. It is essential that anxiety and stress are reduced to a minimum and so the alleviation of pain during and after dental surgery has to be
considered carefully. MANAGEMENT
Anaesthesia General anaesthesia in the cardiac patient is undertaken only in the apprehensive patient and then only after an examination by an anxsthetist who will decide if admission to hospital is advisable. For a local anaesthetic a 2% solution of ’Lignocaine ’ with adrenaline 1:80,000 is highly satisfactory. The use of adrenaline in patients with coronary-artery disease may be questioned because of the risk of vasoconstriction but in my experience there have been no untoward effects. The infliction of pain because the local anaesthetic has worn off too soon may just as easily produce vasoconstriction and precipitate coronaryartery occlusion. As a rule dental extractions should not be carried out within three months of a coronary thrombosis. Antibiotics Patients with rheumatic heart-disease require antibiotic cover for dental extractions since the bacteraemia after such surgery may predispose to subacute bacterial endocarditis. 500,000 units crystalline penicillin and 300,000 units procaine penicillin administered together half an hour preoperatively give adequate protection. Patients with myocardial infarction have no need of prophylactic antibiotics.
.Hoemorrhage The main
danger associated with the taking of anticoagulant drugs is haemorrhage and dental extraction to be properly managed under such circumstances demands close cooperation between the clinical pathologist and the dental surgeon. Opinions differ as to management. Some prefer to reduce the dose of anticoagulant sufficiently to allow the prothrombin-time to return to 50% of normal for at least 48 hours, to cover the period of extractions and the immediate postoperative period (Spouge 1964). Others recommend the withdrawal of anticoagulant drugs for 2 days before dental surgery with resumption the following day. Poller and Thompson (1964), investigating the effect of abrupt withdrawal of anticoagulants, found evidence of a rebound hypercoagulability in the blood with increased risk of thrombosis. Others prefer to operate when the prothrombin-time is in the upper level of a therapeutic range. SURVEY
To assess the results of dental extraction 106 patients (13 inpatients) taking anticoagulant drugs were operated upon with the prothrombin-time adjusted to the therapeutic range of 7-15%thrombotest. This group was comprised of 76 people with myocardial ischaemia, 11 angina pectoris, 7 pulmonary embolism, 8 rheumatic heart-disease, and 4 venous thrombosis. This group was then compared with the same number of patients with
100 normal blood coagulation. In both groups the age incidence was the same. For ease of description patients on anticoagulant treatment were called group A while group B was comprised of those with normal
coagulation.
unnecessary. On average, 6 teeth extracted at any one time from patients taking anticoagulant drugs, but more radical treatment can be undertaken if indicated.
operative ice-packs is
were
I thank Dr. M. C. G. Israels for his advice and Dr. J. McIver and Dr. A. Turner of the department of clinical pathology, Manchester
Methods
Royal Infirmary.
administered as phenindione, Anticoagulant therapy or nicoumalone. The patients attended the phenprocoumon, clinic two before anticoagulant days operation so that the prothrombin-time could be adjusted to the upper level of the therapeutic range using the thrombotest as described by Owren (1959). The prothrombin-time was rechecked on the day of operation and the patient advised to delay the daily dose of was
until the evening. Local anaesthesia was used in all except 4 patients in group A and 18 patients in group B. Of the 4 who had general anaesthesia one patient, with rheumatic heart-disease, had 21 teeth extracted in a single operation. Where indicated antibiotic cover was given as already described. With the exception of 12 patients in group A who required surgical extractions, both groups were treated by routine dental procedures. Only 13 in group A were treated as inpatients. After operation the sockets were digitally compressed and the patient requested to bite on a gauze pad for approximately 30 minutes to arrest hsemorrhage. The patient, if an outpatient, was then allowed to leave. They attended the outpatient clinic on the 3rd day for prothrombin estimations and thereafter every 4-6 weeks for as long as was considered necessary by the clinician responsible for the drug therapy.
REFERENCES
British Medical Journal (1963) i, 801. Owren, P. A. (1959) Lancet, ii, 774. Poller, L., Thompson, J. M. (1964) Manchester med. Gaz. 3, 8. Quick, A. J. (1935) J. biol. Chem, 109, 73. Spouge, J. D. (1964) Oral Surg. 18, 70.
anticoagulant
Complications In both groups there was only one complication. This patient in group A whose thrombotest at the time of operation was 5%. He continued to bleed for 12 hours after the removal of 9 teeth. This bleeding was controlled by the administration of vitamin Kl. was a
DISCUSSION
the behaviour of the two groups in their dental extractions, it was found that, when the patients in group A had the prothrombin-time adjusted to the upper level of the therapeutic range, the postoperative bleeding was no greater than in the normal patient. It was also concluded that most patients on anticoagulant therapy were suitable for outpatient management, that routine dental measures were admissible in those who were not already inpatients, and that recourse to local haemostasis, sutures, and postoperative ice-packs was unnecessary. On average, up to 6 teeth were extracted at any one time from patients in group A.
Comparing
response to
Teeth extracted 1-6
Patients
on
Normal
anticoagulants
patients
89 12 5
46 45 15
7-12
12
but more radical treatment could be carried indicated in the patient on anticoagulant therapy.
out
if
SUMMARY
carried out on 106 patients taking anticoagulant drugs with the prothrombin-time adjusted to a therapeutic range of 7-15% thrombotest (Owren 1959) and the results compared with similar extractions in a control group of the same number. Local anaesthetic was used in all except 4 patients in the anticoagulant group. Most patients may be treated as outpatients, routine measures are permissible in outpatients, and the recourse to local haemostasis, sutures, and postDental extractions
were
Public Health A PIONEER IN THE BALKANS
PORTRAITS, busts, eponymous institutions, lectureships, fellowships, collected papers-these are some of the ways in which great doctors may be honoured. The Andrija Stampar School of Public Health already stands in Zagreb and contains his bust; now comes an English edition of his selected papers.’ Stampar was not a very great thinker or writer, and in any many of the papers suffer somewhat from translation from Serbo-Croat. But he was a man well ahead of his time, with a single, important idea, for which he fought ably, courageously, and singlemindedly throughout his life. He believed that medicine was primarily neither an art nor a science applied to the individual, but a social function which should be freely available to all. In 1911, while still a medical student in Vienna, he set out the views on social medicine which are now reprinted; he lived to see them embodied in the preamble to the constitution of the World Health Organisation, of which he was the first president. case
He had inherited from his father, a village schoolmaster, both his sympathy with the hardships of peasant life and his gift of clear exposition, and he wrote over 70 articles and pamphlets before he was qualified, chiefly on what we should now call " health education ". A contemporary of his schooldays remembers him as quite different from other schoolboys. He was self-reliant, non-conformist and reluctant to yield to the demands of his environment". Early conviction of the evils of alcoholism, for instance, led to lifelong teetotalism. He naturally had a special interest in the " social " diseases and, as a district health officer in Croatia, he also dealt with outbreaks of cholera and smallpox. After the 1914-18 war, he became health adviser to the Croatian Commission for Social Welfare and, at the astonishing age of 31, when still relatively unknown, he was selected for the post of what we should call chief medical officer to the new kingdom of Yugoslavia. The young State had been formed out of the most heterogeneous territories, which had been impoverished by the Balkan wars and the 1914-18 war. Social diseases, such as endemic malaria, syphilis, typhus, trachoma, tuberculosis, were rife and the infant-mortality rate, which was everywhere high, in some places reached the figure of 500 per 1000. What Stampar achieved is set out in two papers in this collection-Five Years of Socio-Medical Work in the Kingdom of Serbs, Croats and Slovenes and Ten Years’ Work on the Promotion of Public Health. At this time he edited and largely wrote two volumes on social medicine as a textbook for the Zagreb Institute, the foundation of which he had inspired. He was now becoming known internationally as a member of the committee of the Health Organisation of the League of Nations. "
By 1930, his left-wing views and the opposition of private
practitioners 1.
had
brought
him into conflict with
powerful
Serving the Cause of Public Health. Selected Papers of Andrya Stampar. Editor: M. D. GRMEK, translated by M. HALAR, revised by L. F. WARING. Obtainable from the Andrija Stampar School of Public Health, Rockefeller St. 4, Zagreb, Yugoslavia. 1966. Pp 258. 87