Cynthia R. Biron, RDH
When a patient presents with hypertension, we assume it is caused by increased peripheral resistance due to a genetic predisposition and/or the many lifestyle causes of cardiovascular disease. Ninety to 95 percent of all cases of hypertension are a result of cardiovascular disease, but 5 to 10 percent of hypertension cases are due to malfunction of other bodily organs or systems or drugs and drug interactions.
The following cases are examples of the importance of taking blood pressures and taking appropriate steps in dealing with the findings of hypertension.
Case 1
Bill Jones, a 32 year old male of average height and weight and a healthy appearance, was a new patient at Dr. Casey`s office. His initial visit was scheduled with the dental hygienist, Gayle. Bill filled out the medical history questionnaire quickly, scanning through the questions and checking "no" to everything, as so many patients do when they are confident that they are very healthy. Gayle greeted him in the reception area and, while she was smiling graciously, she was beginning her patient assessment the moment she looked at him, as most hygienists do for every appointment.
She shook hands with him as she introduced herself and noticed that his hands were clammy. She thought he might be apprehensive about the appointment. She immediately told him that at this appointment she would be taking x-rays and evaluating his oral health. Dr. Casey would do an examination of his teeth, but no actual treatment would occur. After reviewing Bill`s medical and dental history, Gayle asked a few other questions to be sure that, indeed, his history was unremarkable.
Gayle told Bill she was going to take his vital signs and she proceeded to place the blood pressure cuff on his right arm. She took the radial pressure first and was alarmed to discover that the estimated systolic blood pressure was 220!
She decided to try the radial pulse pressure again as she didn`t want to inflate the cuff to 240 if she really didn`t have to, since she knew that would be uncomfortable for the patient. Unfortunately, the estimated systolic blood pressure was 220! With a neutral expression she inflated the cuff until the sphygmomanometer read 240. She released the air lock valve slowly and watched the needle drop. When it struck 224 it jiggled and simultaneously she heard the pook-pook sound of the arterial pulse indicating a systolic blood pressure of 224.
Her eyes fixated on the needle; she could feel her own heart racing from the adrenalin rush she had. She realized this patient might have severe hypertension that could be life threatening. When the needle struck 120 the last pook sound was heard. Could his blood pressure really be 224/120?
She decided to take the reading on his left arm. She told Bill his blood pressure seemed elevated and she wanted to check it again on the other arm to make sure she had the correct reading. By this time Bill got a little concerned and when Gayle took the blood pressure reading on the left arm, it was 228/122. At that point she asked Bill if he ever had any problems with his blood pressure.
Bill replied, "No, I don`t believe so. But I haven`t had it checked in over a year. I`ve always been so healthy. How high is it anyway?"
Gayle said, " Let`s just wait and let Dr. Casey take your blood pressure with his blood pressure kit. I`ll go get him."
Gayle went to Dr. Casey`s office and told him she needed to speak to him right away. When he entered the hallway she told him about Bill`s blood pressure reading. Dr. Casey got his own blood pressure kit and went into Gayle`s operatory. After introductions, Dr. Casey told Bill he wanted to check his blood pressure with a different blood pressure kit to ascertain that the reading is correct. Dr. Casey got a reading of 228/128. At that point, Dr. Casey told Bill his blood pressure reading. He then told Bill that a blood pressure that is so dangerously high requires an immediate medical evaluation.
Dr. Casey said, "I am going to call Dr. Jameson, the internist next door, and Gayle will walk you over there so you can be evaluated."
Dr. Jameson examined Bill and told him he must be admitted to the hospital so that they could treat him immediately to reduce his blood pressure and do a series of tests to determine the cause of the elevated blood pressure."
Bill was admitted to a local hospital where extensive testing was conducted. Doctors there discovered that Bill had a degenerative kidney disease that was the cause of the hypertension. Bill had to begin dialysis treatments, and Dr. Casey and Gayle learned that a year later Bill had received a kidney transplant from his brother.
Case 2
Janet is a hygienist who practices in the western area of the United States. She has been certified to administer local anesthesia to patients and has been successfully doing so for the last five years. She has always been religious about reviewing baseline blood pressure readings before administering local anesthesia to any of her patients.
One day Dr. Jackson asked Janet if she could help him out by administering local anesthesia to his next patient. Harry was out in the reception area where he had been waiting for 25 minutes. Dr. Jackson was behind schedule due to a procedure complication with the patient he was currently treating. Janet had a patient cancellation and was readily available to help anyone in the office who needed her assistance.
Dr. Jackson told Janet to administer 2 carpules of xylocaine with 1:100,000 epinephrine to sextant #1 in Harry`s mouth. Dr. Jackson would be preparing teeth # 2, 4, and 5 for crown and bridge work on Harry. Dr. Jackson stressed the need for palatal injections and a profound anesthesia. The 68 year old patient had been having a lot of dental work done by Dr. Jackson, and there had not been any complications during or after the procedures. The only significant finding on Harry`s medical history was a medication called Zoloft that he had been taking for some time for depression.
When Janet took Harry into Dr. Jackson`s second operatory she looked at his medical history and asked him if there were any changes in his medical history.
Harry said, most emphatically, "No, none at all." Janet looked at the vital sign documentation on the chart and saw that his blood pressure reading of two months ago was 130/84. Janet proceeded to anesthetize Harry`s sextant #1 area as Dr. Jackson had requested.
Approximately one minute after the administration of the anesthesia, Harry began to exhibit the manifestations of a hypertensive emergency. He was very flushed, diaphoretic, and breathing rapidly. Janet immediately took his vital signs: blood pressure 200/110, pulse 180, respirations 32. Janet called in Dr. Jackson who administered nifedipine sublingually and administered supplemental oxygen to Harry with a nasal cannula. Within five minutes Harry`s condition had improved in appearance, but his blood pressure remained at 160/96 - much higher than his original baseline readings of two months ago. Dr. Jackson looked Harry directly in the eye and asked, "Are you sure you haven`t had any health problems or changed medications since we last saw you?"
Harry replied, "My doctor changed my antidepressant, but I didn`t think that would have anything to do with getting a new bridge in my mouth."
The new antidepressant Harry was taking is called Nardil. It is a monoamine oxidase inhibitor. It increases blood levels of epinephrine, norepinephrine, dopamine and serotonin by inhibiting monoamine oxidase, which usually breaks down these circulating neurotransmitters. The use of local anesthesia with epinephrine can cause hypertensive episodes in patients who have therapeutic blood levels of monoamine oxidase inhibitors. Nardil can also elevate blood pressure in and of itself or cause a hypertensive episode when patients ingest foods containing tyramine.
It was apparent that Harry`s blood pressure is now higher than it was when he was taking Zoloft for his depression. Had Janet rechecked Harry`s blood pressure before giving him local anesthesia with 1:100,00 epinephrine, she would have taken the necessary precautions to avoid a hypertensive episode.
A consult with Harry`s psychiatrist revealed that the Zoloft had no longer been as effective in relieving Harry`s depression, and Harry also had been diagnosed with early stage Alzheimer`s disease. Monoamine oxidase increases with age and more so in Alzheimer`s patients. Therefore, antidepressant drugs in this category are being increasingly prescribed to the aged patients, especially those with Alzheimer`s disease.
With all respect to Janet, she was following doctor`s orders, did update the medical history and review vital sign documentation. It is conceivable that the Nardil had elevated Harry`s baseline blood pressure, and/or Harry ate tyramine-containing foods, or Harry had an epinephrine reaction.
We will never know if his blood pressure was elevated before Janet administered the anesthesia, because she didn`t take his blood pressure before administering the local anesthesia. If Janet had not been available to administer local anesthesia to Dr. Jackson`s patient, Dr. Jackson may have been the one who felt responsible for Harry`s hypertensive episode. You see, Harry inadvertently withheld information pertaining to his medical history - a new drug! Harry has early stage Alzheimer`s disease - "he forgets little things like that."
Many causes for high blood pressure
Numerous organ malfunctions and medical conditions, as well as drugs and drug interactions, can cause hypertension. Cardiovascular and cerebrovascular diseases are the most common causes, followed by diseases of many of the endocrine glands - especially the thyroid, adrenal glands and the pancreas. Neurologic disorders involving brain tumors, encephalitis, quadriplegia, and lead poisoning are other causes of hypertension.
Pregnancy-induced hypertension is common. Most pregnant patients will know they are hypertensive, as their blood pressure is taken during their prenatal visits.
Acute stress, sickle cell crisis, and alcohol withdrawal can be contributors to high blood pressure. Drugs which commonly cause elevated blood pressure include oral contraceptives, corticosteroids, appetite suppressants, antihistamines, sympathomimetics, and monamine oxidase inhibitors.
We are not required to determine the cause of a patient`s high blood pressure, but we are required to refer hypertensive patients for a medical evaluation before providing dental treatment of any kind.
In frequent discussions throughout the country, dental hygienists openly state that they do not take blood pressures on their patients on a regular basis.
Their reason? "There just isn`t enough time to take BPs, especially with all the infection control procedures performed between patients."
If using a stethoscope and blood pressure kit is too time consuming, invest in the new wrist type automatic pulse and blood pressure detector. Although the wrist device is not as accurate as the original manual technique, it can still alert you to the fact that a patient has an extremely low or high blood pressure. It only takes a few seconds to wrap the bracelet device around the patient`s wrist and instantly you receive the patient`s blood pressure and pulse readings. If an abnormal reading is noted, further investigation with a manual blood pressure kit can be more definitive in providing exact readings.
Years ago, automatic blood pressure measuring devices were frequently inaccurate. Today`s devices, though, are quite accurate. There is no excuse for not taking blood pressure readings on all new and recall patients. Because of the nature of our dental treatments, the invasiveness, the use of local anesthesia, and the apprehension patients experience in relationship to all we do, we must take blood pressures.
The legal ramifications of not having baseline readings before treating a patient could be complicated and costly should a malpractice suit be issued. There are approximately 23 states in the United States where dental hygienists are legally administering local anesthesia. Are they getting baseline vital signs on all of their patients? Are they taking blood pressure readings before administering local anesthesia at each appointment? It seems hygienists have to go one step further with risk management. They must take blood pressures on every patient each time they are going to administer local anesthesia to that patient. Not only for the sake of the patients, but for the sake of our profession, stringent measures must be utilized.
The author extends her appreciation to the dental team members described in the two cases for sharing their stressful experiences with us. There is much to be learned from these cases - take blood pressures.
References
- Calhoun DA, Oparil S: Treatment of hypertensive crisis. N Engl J. Med 323:1177-1183, 1990.
- Crosby LA (eds): Emergency Care and Transportation : 6th ed. Illinois, American Academy of Orthopaedic Surgeons, 1995 Chapter 5.
- Hallenberg NK: The treatment of renovascular hypertension: Surgery, angioplasty, and medical therapy with converting enzyme inhibitors. Am J Kidney Dis 10(suppl):52, 1987.
- Jarvik LF, Berg L, Bartus R, et al. Clinical drug trials in Alzheimer disease: what are some of the issues? Alzheimer Dis Assoc Disord. 1990;4: 193-202.
- Kaplan NM: Calcium entry blockers in the treatment of hypertension: Current status and future prospects. JAMA 262:817-823, 1989.
- Littenberg B, Garber AM, Sox HC: Screening for hypertension. Ann Intern Med 112:192-202, 1990.
- Mejia AD, Egan BM, Schork NF, Zweifler AJ: Artefacts in measurement of blood pressure and lack of target organ involvement in the assessment of patients with treatment-resistant hypertension Ann Intern Med 112:270-277, 1990.
- Reinikainen KJ, Piljarvi L, Halonen T, et al. Dopaminergic system and monoamine oxidase-B activity in Alzheimer`s disease. Neurobiol Aging. 1987;245-252.
- Wynn RL, Meiller TF, Crossley HL, (eds) Drug Information Handbook for Dentistry. 3rd ed. Hudson, Ohio, Lexi-Comp, 1997-98, pp. 431-432.
Cynthia R. Biron, RDH, is chair of the dental health program at Tallahassee Community College. She is also a certified emergency medical technician.
Reacting under pressure
What would you do if one of your patient`s has a dangerously high blood pressure? Not every office has an internist practicing next door. If your office is far away from a medical facility, should you call 911?
If this is the first time you are seeing a patient (not a patient of record where other baseline blood pressure readings are available for comparison, and no invasive procedures have been performed), you should call the patient`s own physician immediately, inquiring if the physician wants the patient admitted to the hospital or brought to his office. You should escort the patient to the hospital or physician`s office if the patient`s family members or friends are not available.
The deciding factor on calling 911 depends on the reason to believe the patient is experiencing a hypertensive crisis emergency. Factors that indicate a patient is experiencing a hypertensive crisis include:
- A comparison with baseline blood pressure readings that demonstrate that the patient`s readings at previous appointments were within normal limits and the readings at the time of the suspected emergency are significantly higher and climbing.
- The patient has tachycardia, an increased respiratory rate, facial flushing, diaphoresis, and possibly a headache.
- If the manifestations occur after the administration of local anesthesia, there is reason to believe that anesthesia toxicity, epinephrine overdose, or a drug interaction could be the cause of the patient`s state.
An apprehensive patient who is hyperventilating will also exhibit elevated vital signs - but not to the extent of a hypertensive crisis. The dentist will need to make a differential diagnosis or at least an assessment of the abrupt changes in the patient`s vital signs and physical condition.
If the patient of record has never had baseline blood pressure readings recorded in his records to date, the blood pressure readings at the time of the emergency are less significant. No one knows if the patient has been hypertensive for some time or if the findings at this time are indicative of a sudden serious situation.
A hypertensive crisis could lead to a cerebrovascular accident (stroke). When a patient suddenly has an alarmingly high blood pressure such as 200+/100+ and their baseline readings have been under 140/90, it would be wise to call emergency medical services (EMS). The paramedics can advise you while they are enroute and suggest treatment possibilities which usually involve basic life support and the administration of sublingual vasodilators such as nifedipine or nitroglycerine for a patient who is getting progressively more hypertensive. EMT paramedics will assess the patient and determine if the patient should be transported to the hospital.
If the patient refuses to be taken to a medical facility for testing and treatment, he should sign a statement that indicates that he refused to have treatment which was recommended to him for his extremely high blood pressure. The dental office must keep one copy of the statement and provide the EMS with another.
