Have you been asked countless times by patients why dental clinicians need to take blood pressure prior to the appointment? Are you working in an office that has yet to establish a patient triage prior to appointments? Understanding the important role that the dental clinician plays in risk assessment protocol can mean life or death to patients.
Blood pressure is “the amount of pressure of circulating blood against the walls of blood vessels.”1 Blood pressure consists of systolic pressure and diastolic pressure. The systolic pressure is the maximum pressure during one heartbeat, and diastolic pressure is the minimum pressure during two heartbeats. Systolic pressure is the action or pumping of the blood in comparison to the diastolic pressure that is when the heart muscle relaxes and refills with blood. The diastolic pressure is also known as the “resting pressure.”1
The three categories of blood pressure are hypertension or high blood pressure, hypotension or low blood pressure, and normotension or normal pressure. Hypertension is “the most chronic cardiovascular condition in the United States.”2 According to the Centers for Disease Control and Prevention (CDC), “nearly half the adult U.S. population has hypertension.”3 However, only one in four adults who are diagnosed with hypertension have the disease controlled by diet or medication.3
Therefore, dental management precautions in patients with hypertension and hypotension are important in the dental setting on many levels. Blood pressure reading can influence clinician decisions about dental treatment in specific ways.
Blood Pressure Categories
The American Heart Association (AHA) provides a chart to determine the blood pressure categories based on the assessed readings. According to the chart, the normal range of blood pressure is a systolic pressure of 120mm Hg or less, and the diastolic pressure is less than 80mm Hg. An elevated blood pressure will range from 120-129mm Hg systolic and less than 80mm Hg diastolic.
However, hypertension is subdivided into three stages. Stage 1 hypertension indicates a systolic reading of 130-139mm Hg or a diastolic reading of 90mm Hg or higher. Stage 2 hypertension indicates a systolic reading of 140mm Hg or higher or a diastolic reading of 90mm Hg or higher. Lastly, a hypertensive crisis is a systolic reading higher than 180mm Hg and/or a diastolic reading of higher than 120 mm Hg.4
Risk Factors of High Blood Pressure
Medical history assessment of a patient is imperative in determining the risk of high blood pressure. Uncontrolled risk factors include genetics, age, sex, and race/ethnicity. In 2017, the CDC implemented the new high blood pressure guidelines that indicate 54% of black males have hypertension as opposed to the 46% of white adults, 39% of Asians, and 36% of Hispanics.3 Furthermore, the risk of hypertension is elevated at the age of 65 or older based on Harvard Health Publishing, which indicates 70-79% of males age 55 or older are classified as having hypertension.5 The rise in hypertension with age is due to the increased stiffness of arteries due to long-term plaque buildup, increasing the risk of cardiovascular disease.
However, controlled risk factors may play a role in hypertension, and examples include an unhealthy diet, lack of physical activity, high alcohol consumption, smoking, obesity, and diabetes. Favorable health choices to reduce the risk of hypertension are foods low in cholesterol and saturated fats, daily exercise, minimal alcohol consumption, and a tobacco-free lifestyle.3
How do the controlled risk factors affect blood pressure?
- Alcohol, high cholesterol, and fatty foods increase plaque buildup in arteries, decreasing the circulation of blood to the heart, thus causing high blood pressure.
- Nicotine in tobacco products increases carbon dioxide, therefore decreasing the oxygen in the blood.
- Diabetes affects six out of 10 people. However, the relationship between high blood pressure and diabetes is unknown, the risk for cardiovascular disease and stroke increases. Overall, the controlled risk factors of obesity, high cholesterol, or a diet high in fat and inactivity may be the coordinating factors that contribute to diabetic patients with high blood pressure.3
Dental Treatment Considerations
The dental considerations of the dental patient to prevent a decrease in blood pressure involve patient position. Orthostatic hypotension is “when there is a drop in blood pressure when standing or laying for long periods of time.”2 The risk factors involved in orthostatic hypotension are age, diabetes, and autonomic dysfunction.
During the dental visit, the patient being positioned supine for long lengths of time may increase the risk of orthostatic hypotension. Typically, light-headedness or dizziness are telltale signs. To prevent orthostatic hypotension, a gradual incline is recommended.2 In the case of the dental patient feeling light-headed or dizzy, having the patient sit for a period will help regulate blood pressure.2
On the other hand, the treatment considerations for a dental patient with high blood pressure are a bit more complex due to the use of local anesthetics. The local anesthetics used in dental treatment contain epinephrine, which is a vasoconstrictor. The use of epinephrine increases the quality of anesthesia while decreasing the quantity needed during treatment. When a vasoconstrictor, such as epinephrine is added to the anesthetic to contradict a patient’s vasodilation quality, the blood vessels are constricted, thus reducing blood flow to the injection site.6
Some precautions should be taken to reduce the risk of any adverse reactions for a patient with high blood pressure when using local anesthetics containing epinephrine. First, limiting the epinephrine dose will prevent the risk of negative effects. Second, using a slow injection technique and aspirating carefully will reduce the possibility of harmful results. Last, avoiding the use of a gingival retraction cord, which may cause a higher concentration of epinephrine at the site, is recommended.2
How to Proceed with Dental Treatment
A pre-operative blood pressure reading should be taken and logged in the dental treatment notes. The pre-operative blood pressure reading will determine how to proceed with dental care and outpatient dental care recommendations. A blood pressure reading of <160/100 mm Hg would indicate no modifications in elective or emergent dental care.
However, a blood pressure reading of >160/100 mm Hg would indicate the blood pressure measurement should be retaken and the following steps enacted for elective care:
- If the patient is seeking elective care and the second reading is lower, then proceed as normal.
- If the second reading continues to be high, then dismiss with the recommendation that the patient follows up with the primary care provider for medical consultation.
If the patient is seeking emergency dental care, then the protocol is as follows:
- Retake the blood pressure, and if the second reading is lower or no higher than 180/109 mm Hg, then proceed.
- But if the secondary reading remains high but not above 180/109 mm Hg, monitor every 15 to 20 minutes, as pain may be a contributing factor.
- Finally, if a blood pressure consistently reads >180/109 mm Hg, the patient must seek medical consultation immediately, and no dental treatment shall be executed. Furthermore, with any blood pressure between 160/100mm Hg to 180/109 mm Hg, it would be in the patient’s best interest to take a post-operative blood pressure reading to determine if a medical consultation may be needed.2
Factors to Achieve Accurate Blood Pressure Readings
Achieving an accurate blood pressure reading is important for the dental patient and dental clinician. Implementing an accurate blood pressure setting will decrease stress to the patient and increase time management for the dental clinician.
As recommended by the American Academy of Family Physicians (AAFP), many key elements may play a role in reducing a higher-than-normal reading.7 First, the patient should avoid caffeine, exercise, and smoking 30 minutes before the dental visit, all of which will help in preventing a higher-than-average reading.
Secondly, patients should relieve their bladder prior to being seated and refrain from talking or laughing while blood pressure reading is being taken. Also, patient position is important. The patient should be relaxed with both feet on the floor.
Most importantly, the placement of the blood pressure cuff is critical. Removing clothing that may obstruct the cuff placement and the proper position of the cuff while supporting the patient’s arm in an elevated position are imperative to an accurate blood pressure reading. Proper cuff position includes placing the arm cuff where the middle of the cuff is level with the right atrium and midpoint to the sternum.
Arm Cuff vs. Wrist Cuff
Although a wrist and arm blood pressure monitor both have the same goal in mind, the American Heart Association (AHA) recommends an arm cuff for home monitoring.8 The reason for the AHA recommendation is that the wrist cuff may be less accurate than an arm cuff device.
Typically, wrist cuffs read higher as a result of improper technique. While using the wrist cuff, it is important to understand that the veins in the wrist are narrower than the upper arm and closer to the skin, and, therefore, the arm and wrist must be at heart level to achieve accurate readings. Although the arm cuff is recommended, an inaccurate blood pressure reading may result with an arm cuff if the proper technique is not implemented or the cuff is ill-fitted.8
The role that dental clinicians play in the patients’ health assessment is important to maintaining patients’ confidence as well as their safety. Hence, pre-operative blood pressure is key in achieving these goals. The age-old question presented by patients is, “Why do I need my blood pressure taken for a dental appointment?” The accurate answer and imperative objective are to understand the effects of blood pressure and dental contraindications.
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- Definition of Blood Pressure. Wikipedia. Retrieved from https://en.wikipedia.org/wiki/bloodpressure
- Hypertension (High Blood Pressure). (2020, July 29). American Dental Association. Retrieved from https://www.ada.org/en/member-center/oral-health-topics/hypertension
- High Blood Pressure. (2020, February 24). Center for Disease Control and Prevention. Retrieved from https://www.cdc.gov/bloodpressure/risk_factors.htm
- Understanding Blood Pressure Readings. (n.d.). American Heart Association. Retrieved from http://www.heart.org/en/health-topics/high-blood-pressure/understanding-blood-pressure-readings
- Reading the New Blood Pressure Guidelines. (2020, June 1). Harvard Health Publishing. Retrieved from https://www.health.harvard.edu/heart-health/reading-the-new-blood-pressure-guidelines
- Sisk, A.L. Vasoconstrictors in Local Anesthetics for Dentistry. The Journal of Sedation and Anesthesiology in Dentistry. 1992; 39(6): 187-193. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2148619/
- Lefevre, M. ACC/AHA Hypertension Guidelines: What Is New? What Do We Do? American Family Physicians. 2018; 97(6): 372-373. Retrieved from https://www.aafp.org/afp/2018/0315/p372.html
- Sheps, S.G. (2021, February 27). Wrist Blood Pressure Monitors: Are They Accurate? Mayo Clinic. Retrieved from https://www.mayoclinic.org/diseases-conditions/high-blood-pressure/expert-answers/wrist-blood-pressure-monitors/faq-20057802