By Rohan Rege, Junior at South Forsyth High School, Cumming, GA and Anushka Kadam, Sophomore at Lambert High School, Suwanee, GA
Abbreviations used in the manuscript are:
AK: Anushka Kadam
ARL: Atul Laddu
RR: Rohan Rege
RR: Anushka and I are the members of Georgia Thrombosis Forum (GTF), an organization devoted to the spread of awareness of thrombosis in the community. After setting up several booths at medical conventions where we talked with the attendees and told them about the risks of thrombosis and how to manage them, the GTF moved on to conduct interviews of health care professionals, such as pharmacists and physicians, to know the challenges they see in their practice.
Our next logical step was to see if there are any risks involved in various common procedures people undergo on a routine basis. We know that almost everyone goes to a dentist, and we therefore chose to research if there is any risk of thrombosis when one goes to a dentist.
We fully realize that routine dentistry is safe, and rarely involves thrombotic complications. However, the purpose of our interview with you is a bit different.
Our objectives of the interview are:
1. To make an effort to differentiate the safe population (not at risk for thrombotic conditions following routine dentistry) from those who may be at risk for these events.
2. To define which population will be at risk for thrombotic conditions.
3. We are going to research a variety of surgical conditions and check the risk of thrombotic events.
4. By conducting this research, we hope to come to a rough estimate of which surgeries or procedures are safe, which are at medium risk, and which are at high risk of developing thrombotic complications.
There is a multitude of evidence that supports the existence of a connection between Dentistry and Thrombosis. If you are going to have a dental surgery in the near future, it will be to your advantage to know the risk factors.
So let us move on….
AK: Dr. Pai: How long have you been practicing dentistry?
Dr. Pai: I have been practicing since 1999. I practiced dentistry briefly in India for few years, and have been practicing in the U.S. since 2004.
AK: Has it been always in Georgia, or in some other state?
Dr. Pai: As a dentist, I have always been in Georgia, and I am a registered dental hygienist in the state of Massachusetts.
AK: Do you treat children, adults, or elderly patients?
Dr. Pai: I treat anyone who has teeth (6 month old to 101 years old).
AK: Have you seen a difference, or perhaps a better word-challenge in any of the age groups?
Dr. Pai: Yes, each age group has its own unique set of considerations. With pediatric patients, you have to keep in mind to cultivate good oral habits of correct brushing techniques. In very young children, it is difficult to articulate oral needs, and therefore the parents have to remain vigilant. Young children very rarely sit still , so it could be difficult to perform some procedures.
In the aging population, I have to take into consideration all medical conditions and medications they might be taking. Missing teeth in my patients need to be attended to. With adults, obesity and diabetes are rampant which all affect how we manage teeth. Dental anxiety is also a huge factor. In addition, I find that patients from India are very
resistant to visiting a dentist; so are the patients who are from the medical profession.
RR: Are the risk factors common between dental and non-dental patients?
Dr. Pai: Yes, they are very similar.
AK: Is there a difference in treatment with different situations?
Dr. Pai: Yes, there is a difference, depending upon timing, and procedure performed.
ARL: Is this something you do normally and is it generally taught in the dental school?
Dr. Pai: As a part of our curriculum, we are taught total patient care. Post-operative pain and infections and its spread through facial spaces as well as bleeding complications can occur with certain dental procedures if proper care is not exercised.
You have to weigh multiple factors and then come to a conclusion as to how you want to deal with the patient.
ARL: When you see a patient, do you customize treatment?
Dr. Pai: Yes, I do customize the treatment, based on history, findings and other existing conditions.
AK: How about different races you treat? Is there any difference in treatment in between different races?
Dr. Pai: As far as treatment goes it does not differ much between different races, but some things we must keep in mind. For example, Asian women have a small stature and small mouth, so we use smaller sized tools and appliances. Other than a few differences, there are really no treatment differences.
AK: How about nationalities? Is there any difference?
Dr. Pai: No, but there are some challenges such as lack of access to oral care in minority and immigrant population.
ARL: Is there a major treatment difference between different countries?
Dr. Pai: Standard of dental care in the U.S. is much higher and consistent than that in most other countries. Most crown and bridge treatments completed in India for example have an inconsistent quality. This of course makes it harder for us in the U.S. to transition treatment of patients because of liability issues.
Sometimes patients go to India and get dental treatment, since they feel that it is less expensive in India. I do not advise going back to India to get oral treatment. I try to educate my patients on the risks associated with the procedures in countries and not conducted at minimal
standards. For example, sometimes crowns are not placed in correctly, the tooth can decay inside, and the dentist may find this when it is too late. Also sterilization standards are inconsistent.
Patients in tier 3 or 4 (defined below) will be handled by an oral surgeon in a hospital type setting. The oral surgeon will consult a physician if there are several risk factors.
AK: Please help us understand what constitutes dental treatment. We understand that dental treatment involves the following procedures:
1. Construction of dentures
2. Scaling/polishing and fillings, crowns, bridges
3. Invasive procedures performed root canal treatment, local anesthesia
4. Tooth Extraction
5. Minor oral surgery
6. Periodontal surgery
Dr. Pai: This is a good list of the things that constitute dental treatment.
AK: Let us now talk about risk of thrombosis in patients undergoing dental treatment.
RR: From our research, the American College of Chest Physicians (ACCP) has separated surgical patients based on their risk of contracting deep vein thrombosis (DVT). The continuum ranges from Low-Risk to Highest risk.
RR: The first tier, low-risk, includes 40 year and younger patients undergoing minor surgery with no prior risk factors. No specific preventative actions need to be taken, but the patient should be active immediately following discharge from the hospital.
RR: The second tier, moderate risk, includes patients between the ages of 40 and 60 having a minor surgery with no prior risk factors, and patients under the age of 40 having a major surgery with some sort of risk factor present. In order to lower the risk of thrombosis, it is recommended that the patient be administered low-dose unfractionated heparin (LDUH) every 12 hours, or less than 3400 U/day of Low Molecular Weight Heparin (LMWH).
RR: The third tier is a high risk one, which includes patients over the age of 60 undergoing a minor surgery, and patients over the age of 40 undergoing a major surgery with multiple risk factors, such as trauma, present at the time of or after the surgery. The risk in this group can be lowered by administration of low dose unfractionated heparin every eight hours, or greater than 3400 U/day of low molecular weight heparin.
RR: The fourth and highest risk tier includes patients over the age of 40 having a major surgery with several risk factors, including previous DVT, cancer, hypercoagulable condition, major trauma, hip surgery, and/or a spinal cord injury. The prophylaxis for this group of patients includes less than 3400U of LMWH per day, fondaparinux, warfarin (if the patient has an INR of 2-3).
Could you please comment on these categories of patients?
Dr. Pai: We usually stay within the tooth structure, and therefore the risk of thrombosis is very low. I usually handle patients in tier 1 and 2.
Patients in tier 3 or 4 will be managed by an oral dental surgeon in a hospital type setting. The oral dental surgeon will consult a physician if there are several risk factors.
ARL: As dentists, are you allowed to give a low molecular weight heparin like Lovenox?
Dr. Pai: No, we are only allowed to prescribe medications related to oral health and conditions affecting the oral cavity and surrounding head and neck area. For anything beyond the scope of dentistry we have to consult with a physician.
AK: We understand that due to genetic factors, white patients are ten times as likely to develop thrombosis as their Asian counterparts. The incidence rapidly increases as age increases.
DR. Pai: Yes, this is correct. Thrombosis has not been much of a problem in dentistry, since most of the patients who receive dental surgery are young adults who tend to become active directly following discharge. However, new advances in dental surgery have resulted in some long surgeries for elderly patients, which increases the risk of thrombosis, and in whom preventive measures are strongly recommended.
AK: We were told that some mechanical preventative measures that can be taken include: compression stockings, pneumatic compression devices, and venous foot pumps. Pharmacological methods include use of antiplatelet agents, such as aspirin, antithrombotic agents, such as LDUH or LMWH, Vitamin K antagonists, such as warfarin, and synthetic pentasaccharide factor Xa inhibitors, such as fondaparinux.
Ramesh Babu and his colleagues examined two different cases of patients who developed deep-vein thrombosis after undergoing maxillofacial surgery (Ramesh Babu et al, 2013)
AK: The first patient, a 40-year old woman, had a left ankle and a left mandible fracture. The patient was given general anesthesia, and the surgery lasted a total of 45 minutes. Two days after the surgery, the patient had “mild swelling in right leg”. On the 5th post-operative day, the swelling became unbearably painful and the patient was diagnosed with deep-venous thrombosis.
AK: The second patient, a 44-year old man, was suffering from oral submucous fibrosis. He was treated with the release of fibrous bands. The operation time was 105 minutes. Four days after the surgery, the patient began complaining about calf muscle pain in his left limb. Color Doppler revealed the presence of thrombosis in the peroneal vein of the left limb. He was diagnosed with deep-vein thrombosis.
AK: The authors arrived at the conclusion that any major surgery with general anesthesia lasting longer than 30 minutes is a significant risk factor for DVT. Acquired risk factors for DVT include immobility, surgery, trauma, neurological disease with paresis, malignancy, central venous catheterization, transvenous pacemaker placement, varicose veins, old age, obesity, pregnancy, history of previous DVT, and hormone therapy.
Dr. Pai, could you please correct us on our assumptions?
Dr. Pai: I agree with the literature, but I just do not see this picture in my practice.
RR: We have read the British Committee for Standards in Hematology: Guidelines for the management of patients on oral anticoagulants requiring dental surgery
These guidelines tell us the following;
The risks of bleeding associated with dental extraction in individuals not receiving oral anticoagulants is approximately 1%.
The risk of bleeding in anticoagulated patients undergoing oral surgery or dental surgery is common, but minimal.
The risk of significant bleeding in patients on oral anticoagulants and with a stable International Normalization Ratio (INR) in the therapeutic range 2-4 is minimal, and there is no need to alter the anticoagulant regimen.
The risk of bleeding may be minimized by the use of surgical or collagen sponges and sutures.
Patients taking warfarin should not be prescribed non-selective drugs such as ibuprofen and naproxen.
Dr. Pai, what is your opinion on these recommendations?
Dr. Pai: I know about these recommendations, and they are great.
AK: Clinicians who administered larger doses of oral anticoagulants to achieve the INR, resulted in an increased incidence of hemorrhage.
RR: The following patients on warfarin should NOT have a surgical dental procedure in the primary care settings:
Patients on oral anticoagulants with co-existing medical problems e.g. liver disease, renal disease, thrombocytopenia or who are taking anti-platelet drugs.
Dr. Pai, any comments?
Dr. Pai: You are correct, these are basically the British standards for hematology. The U.S. has similar guidelines.
When we see a patient on an anticoagulant, we have to make sure that the risk to benefit ratio is very minimal. We do not stop anticoagulants for surgical procedures. In these modern days, most dental procedures are absolutely safe even in most patients on anticoagulant therapy.
AK: Is it safe to discontinue anticoagulants prior to dental surgery?
Dr. Pai: We do not recommend stopping the anticoagulant drugs for a routine dental procedure. Without the anticoagulant/antiplatelet medications, these patients are at higher risk for blood clot development, which could result in thromboembolism, stroke, or myocardial infarction (MI).
ARL. Is it common to get a surgical clearance prior to dental surgery on a patient who is on anticoagulant drug?
Dr. Pai: If I have even a slightest doubt, I will ask for surgical clearance.
In February 2007, the American Heart Association, the American College of Cardiology, the Society for Cardiovascular Angiography and Interventions, the American College of Surgeons, and the American Dental Association published their consensus opinion about drug-eluting stents and antiplatelet therapy (e.g., aspirin, clopidogrel, ticlopidine). The consensus opinion states that healthcare providers who perform invasive or surgical procedures (e.g., dentists) and are concerned about periprocedural and postprocedural bleeding should contact the patient’s cardiologist regarding the patient’s antiplatelet regimen and discuss optimal patient management, before discontinuing the antiplatelet medications. Given the importance of antiplatelet medications post-stent implantation in minimizing the risk of stent thrombosis, the medications should not be discontinued prematurely.
AK: The risk of thrombosis associated with temporarily discontinuing anticoagulants prior to dental surgery is small, but in some cases, could be potentially fatal.
I now understand that the risk of major bleeding in patients undergoing routine oral surgery if anticoagulants are continued is very minimal. Although some patients had minor oozing treated with local measures, more that 98% of patients receiving continuous anticoagulants had no serious bleeding problems.
Dr. Pai: This is exactly what I have found in my practice. We use mechanical pressure and local hemostatic agents like surgicel and gelfoam to manage bleeding, if it occurs.
ARL: You have patient with AFib, and the patient is on Pradaxa. Patient wants to have a major dental procedure, what would you do?
Dr. Pai: On the basis of limited evidence, there is a general consensus that in most patients who are receiving the newer target-specific oral anticoagulants such as Pradaxa and undergoing dental interventions (in conjunction with usual local measures to control bleeding), no change to the anticoagulant regimen is required. If I have a patient needing major procedures like multiple extractions or has co morbid conditions, poor oral health, it would be better if the patient is treated by an oral surgeon in consultation with the physician instead of in a primary care setting.
We deal with thrombosis in context of the potential for bleeding complications during dental procedures only.
Dr. Pai, what have been your observations in your practice?
Dr. Pai: Preventive care is always the key. If you know the patient coming to see you regularly, preventive care is generally carried out. The mouth, which is the gateway to the body, has a lot of bacteria, so it is the responsibility of every dentist to keep it clean. Prevention is key to preventing potential complications. If I suspect that something is not within normal parameters, I
will immediately send the patient to an expert physician, or a dental surgeon.
Dr. Pai: In normal uncomplicated cases with a history of stable, normal INR levels, there may not be a need to get an INR, but I would still consult his / her physician. If I have a patient with multiple extractions (3+ extractions) and poor oral health, it would be better if the patient is managed by an oral surgeon.
Summary of key recommendations
RR: The risk of significant bleeding in patients on oral anticoagulants and with a stable INR in the normal therapeutic range 2-3 is very small and the risk of thrombosis may be increased in patients in whom oral anticoagulants are temporarily discontinued. Oral anticoagulants should not be discontinued in the majority of patients requiring out-patient dental surgery including dental extraction (grade A level Ib).
AK: Recommendations: For patients stably anticoagulated on warfarin (INR 2-3) and who are prescribed a single dose of antibiotics as prophylaxis
a. The use of oxidized cellulose (Surgicel) or collagen sponges and sutures (grade B, level IIb).
b. 5% tranexamic acid mouthwashes used four times a day for 2 days (grade A, level Ib). Tranexamic acid is not readily available in most primary care dental practices.
RR: For patients who are stably anticoagulated on warfarin, a check INR is recommended 72 hours prior to dental surgery (grade A, level Ib)
AK: Patients taking warfarin should not be prescribed non-selective NSAIDs and COX-2 inhibitors as analgesia following dental surgery (grade B, level III), because they have a higher risk of bleeding .
RR: The risk of bleeding in anticoagulated patients undergoing oral surgery or dental surgery in anticoagulated patients is common and historically their management has been controversial following early reports of major bleeding in such individuals. Many of the early reports of hemorrhage associated with dental surgery during this period predated the standardization of oral anticoagulant control by means of the INR. In 1954, the American Heart Association recommended a therapeutic range for oral anticoagulant therapy of a prothrombin time ratio (PTR) of 2 – 2.5. Later, the use of less sensitive commercial thromboplastins was not accompanied by a change in the target PTR ratio.
Clinicians, therefore, administered larger doses of oral anticoagulants to achieve the target ratio, resulting in an increased incidence of hemorrhage. The development and introduction of the INR did not take place until 1983.
AK: The risks of bleeding associated with dental extraction in individuals not receiving oral anticoagulants is approximately 1%. In a review of 10 studies of patients undergoing dental surgery and in whom oral anticoagulants were continued, 9% (89/990) had delayed postoperative bleeding and in 3.5% of cases this was
classified as ‘serious’ i.e. not controlled by local measures. Other studies have reported the incidence of minor bleeding as higher and in some cases up to 50%.
However, the interpretation and comparison of bleeding rates in patients undergoing oral surgery is difficult as rates for different procedures are not analyzed separately,
the definitions used to describe serious bleeding vary and surgery can involve the use of differing treatments to secure hemostasis.
Potentially invasive procedures performed in primary care would include:
• Endodontics [root canal treatment] not too worried about bleeding
• Local anesthesia [infiltrations, inferior alveolar nerve block, mandibular
blocks] not too worried about bleeding
• Extractions [single and multiple]
• Minor oral surgery- specialist
• Periodontal surgery- specialist
• Biopsies oral surgeon
• Subgingival scaling – not too worried
RR: Which patients on warfarin should NOT have a surgical dental procedure in the primary care setting?
Dr. Pai: The answer is for patients on oral anticoagulants with co-existing medical problems e.g. liver disease, renal disease, thrombocytopenia or who are taking anti-platelet drugs. Such patients may have an increased risk of bleeding.
Patients requiring surgical procedures not listed above. Such patients should be referred to a dental hospital or hospital-based oral and maxillofacial surgery department. Dental surgeons in the primary care setting often have the necessary skills to undertake any of the procedures listed above in the context of the anticoagulated patient.
My suggestion is that every dentist should always treat the patient within his / her comfort zone.
AK: In the review of Wahl, 5/493 (1%), patients undergoing 542 dental procedures and in whom anticoagulants were withdrawn specifically for surgery, had serious embolic complications of which 4 were fatal.
The four deaths comprised: a fatal cerebral embolism 17 days after discontinuing warfarin; 1 fatal myocardial infarction 19 days after interruption of therapy for 9 days; 1 fatal cerebral thromboembolism 5 days postoperatively and 1 died from a thromboembolism but no other data are available.
The risk of major bleeding in patients undergoing oral surgery if anticoagulants are continued.
Wahl reviewed 26 papers comprising 2014 dental surgical procedures in 774 patients receiving continuous warfarin therapy, including 1694 patients undergoing single, multiple extractions and full mouth extractions. This meta-analysis included patients with an INR up to 4.0. Although some patients had minor oozing treated with local measures, more that 98% of patients receiving continuous anticoagulants had no serious bleeding problems. Many of the procedures were performed in patients with an INR above the present recommended therapeutic levels of anticoagulation.
ARL: While in medical school how much coverage did you have about thrombosis?
Dr. Pai: Not a lot, but I have seen a lot of patients on anticoagulants.We deal with dental procedures, but we do not deal with thrombosis, because we do not treat thrombosis.
Dr. Pai, what have been your observations in your practice?
ARL: Prevention is always good, is it carried in the same manner back home in India?
Dr. Pai: No, there is a lack of awareness of the importance of preventive oral care. There is a lack of dental awareness even in the media.
In the Indian community here in the U.S., dental anxiety is very high and it stems from trust issues that come from treatment recommendations that patients perceive are not necessary.
Rohan and Anushka: Thanks Dr. Manasi, this has been a great experience talking with you and understanding the challenges in dentistry that you face on a daily basis.
We definitely achieved our objective. We learned so much about the effect and need for precautions of thrombosis in the dental field. We learned more than we had intended to find out!