Risk Assessment and Prevention of Medical Complications
By Bradford R. Johnson, DDS, MHPE
“An ounce of prevention is worth a pound of cure.” (attributed to Benjamin Franklin circa 1700’s)
Although serious medical complications related to dental treatment are believed to be rare, careful pre-operative evaluation is essential, especially since patients are living longer and age is an independent risk factor for medical complications (1). In addition to age, ASA physical status classification and stability of systemic disease are significant preoperative risk factors.
A challenge all clinicians should consider is that positive responses to questions on standard health history forms do not clearly lead to specific determination of risk for dental treatment. Adding to this, patients may fail to disclose potentially relevant details of their medical history on the assumption that those details are not important (2). During the initial patient interview, it should be confirmed that the list of medications is consistent with reported findings on the health history.
As a brief starting point, consider cardiovascular disease. If we exclude alcohol, opioids, and cannabis, cardiovascular drugs (primarily antihypertensives) and anticoagulants are two of the most common drug classes related to emergency hospital admissions (3). The top ten most frequently prescribed drugs include four antihypertensive medications and direct acting anticoagulants (DOACs) (when grouped together as a drug category).
Cardiovascular disease and associated sequalae (e.g., hypertension, coronary artery disease, arrhythmias, and congestive heart failure) is the most common chronic disease that can be associated with increased risk.
Is there a simple way to quantify risk for an adverse event during dental treatment? The short answer is: no, but several strategies may be considered. First, consider three factors: ASA status, estimated procedural stress, and patient’s self-reported anxiety level. ASA 4 patients will almost always require a medical consult and treatment in a facility that is equipped for continuous monitoring and emergency care intervention if needed. ASA 3 patients present with moderate to severe systemic disease that limits activity but is not incapacitating. Patients in the ASA 3 category can usually be safely treated in a properly equipped office (that is: trained staff, supplies, and equipment to manage a medical emergency if needed), but a medical consult may be advisable. A stress reduction protocol should also be considered. This could include any or all of the following: morning appointments, shorter appointments, oral premedication (e.g.: triazolam 0.25mg prior to the appointment – this may require a sedation permit in some states), N2O/O2 sedation, limited use of epinephrine, and adequate pain management.
When compared to NS-RCT, surgical RCT (which would typically score higher on a procedural stress scale than NS-RCT) induces more significant physiologic changes, including increased heart rate and higher systolic blood pressure (4). Patients with above average dental anxiety are also at greater risk for significant physiologic changes, and therefore potentially at increased risk of an adverse cardiovascular event (4).
Using a risk assessment index (RAI) composed of 14 variables, Yan Q et al. found that even minor surgical procedures are associated with high risk for patients with frailty (5). Endodontic microsurgery was not specifically considered in this study although it could reasonably be considered a “minor surgical procedure.” In this group of patients (frail), clinicians should carefully consider whether the potential benefits of the surgical procedure outweigh the increased risk (5).
Another potentially useful risk assessment tool is consideration of a patient’s functional capacity as measured in METs (metabolic equivalent tasks) and reserve capacity. This provides a general idea of a patient’s ability to handle additional stress. For example, 1 MET would represent oxygen consumption while sitting quietly and a 4 MET score would indicate the oxygen consumption during mild exercise such as raking leaves or climbing a flight of stairs without shortness of breath, fatigue, or chest pain. Patients unable to meet a 4 MET demand during these normal daily activities are at an increased risk for serious perioperative CV event during dental treatment due to lack of reserve capacity (6).
The prevalence of hypertension in the U.S. using current guidelines of >130/80 is estimated to be approximately 45% (7). A common clinically relevant concern is deciding when blood pressure is too high to proceed with dental treatment. Yarrows et al., conducted a review of the literature and concluded that cancelation of a dental appointment is seldom necessary based on blood pressure, in patients under a physician’s care (8). In the absence of angina pectoris or signs or symptoms of acute congestive heart failure, a high preoperative blood pressure less than 180/110 is not an indication to postpone or cancel a dental appointment. Blood pressure > 180/110 may even be acceptable if certain conditions described by Yarrows et al are met (8). Even so, a commonly accepted maximum preoperative blood pressure of less than 180/110 is a reasonable guide for all routine dental procedures with the possible exception of patients with significant dental anxiety, multiple risk factors, and/or surgical procedures that may require local anesthetic with higher concentrations of epinephrine (9).
References:
1) Reuter NG, Westgate PM, Ingram M, Miller CS. Death related to dental treatment: a systematic review. Oral Surg Oral Med Oral Pathol Oral Radiol 2017;123:194-204.
2) Erian D, Quek SYP, Subramanian G. The importance of the history and clinical examination. JADA 2018;149(9):807-814
3) Ayalew MB, Tegegn HG, Abdela OA. Drug Related Hospital Admissions; A Systematic Review of the Recent Literature. Bull Emerg Trauma 2019 Oct;7(4):339-346.
4) Georgelin-Gurgel M, et al. Surgical and Non-surgical Endodontic Treatment-Induced Stress. J Endod 2009;35:19-22.
5) Yan Q, Kim J, Hall DE, Shinall Jr MC, et al. Association of Frailty and the Expanded Operative Stress Score with Preoperative Acute Serious Conditions, Complications, and Mortality in Males Compared to Females: A Retrospective Observational Study. Ann Surg. 2023 Feb 1;277(2):e294-e304.
6) Little and Fallace’s Dental Management of the Medically Compromised Patient. 10th Ed. 2024. p.8
7) ACC/AHA High Blood Pressure Guidelines Lower Definition of Hypertension. November 2017.
8) Yarrows SA, Vornovitsky O, Eber RM, Bisognano JD, et al. Canceling dental procedures due to elevated blood pressure: Is it appropriate? JADA 2020;151(4):239-244. JADA 2000;151(4):239-244.
9) Little and Fallace’s Dental Management of the Medically Compromised Patient. 10th Ed. 2024. p.44.
Dr. Bradford Johnson is a current Counselor and a Past President of the ABE.