When should I take a patient’s blood pressure and what are the guidelines for dental treatment?
This question was submitted by a general dentist: When should I take a patient’s blood pressure and what are the guidelines for dental treatment?
Drs. Ian Furst (Coronation Dental Specialty Group) and Suham Alexander provided this quick initial response.
The guidelines regarding the frequency of vital sign measurement vary by region, but taking them as a baseline can be important for future appointments or during crisis such as syncopal episodes. Their measurement can also be used to screen for undiagnosed or uncontrolled medical issues such as atrial fibrillation and hypertension.
My own rationale for taking a blood pressure and pulse at every dental visit is as follows:
- Many patients visit us more frequently than their physicians, which allows us to be an effective point of screening for cardio-vascular disease. In this day and age of anti-hypertensives, we sometimes forget the risk that untreated hypertension can pose. For instance, untreated severe hypertension has previously been reported to have a 5-year mortality of 84%.2 With that in mind, a diagnosis of hypertension is normally made by a qualified healthcare provider after 3 visits (>140/90) or by a 24-hour monitor (>135/85)3 so we can only be effective in screening, not diagnosis.
- On many occasions I have found a patient with severe hypertension (>180 systolic or >110 diastolic), an irregular pulse (most commonly due to undiagnosed atrial fibrillation) or severe tachycardia (due to atrial fibrillation with rapid response). All of these disorders can cause rapid end-organ damage (heart attack, stroke and renal failure) if not addressed. On one occasion, an asymptomatic, 88 year old female presented with a heart rate of 160 bpm. How long can an 88 year-old’s heart beat that fast? The answer, of course, is not very long. This case underscores the importance of taking the pulse prior to treatment.
- While not directly applicable to minor treatment under local anaesthetic, there is good reason to delay elective care when the diastolic is >110 or the systolic is >180 mmHg. Severe hypertension has been associated with higher perioperative complications under general anaesthesia (heart attack and stroke) and higher perioperative mortality.5 Complicating the situation is that treatment of hypertension in the immediate pre-operative and peri-operative period has not been shown to decrease mortality. A definitive study is now unlikely, since treatment is recommended to everyone with severe hypertension so the debate regarding how high is high enough to cancel surgery continues5. Anecdotally, I’ve had two patients where severe hypertension was identified on consultation, the surgery was delayed for treatment of it but the patients still had a massive strokes within weeks.
Dentists who use parenteral sedation may choose to be wary of patients with poorly controlled hypertension. Their blood pressure can have rapid and wide elevations as well as drops leading to compensatory changes in heart rate that require pharmacologic intervention.
References
- Little JW, Falace DA, Miller CS, Rhodus NL. Little and Falace’s Dental Management of the Medically Compromised Patient. 2013. Elsevier Mosby. St. Louis, MO.
- Miller RD. Miller’s Anesthesia 7th edition. 2010. Churchill Livingstone/Elsevier, ISBN: 9780808924135.