Quality Resource Guide l Screening and Monitoring Blood Pressure in Dental Practice 3rd Edition 4 www.metdental.com When measuring BP, the manual method requires auscultation of the blood pressure, whereas an automated system depends on oscillometric devices. Each technique consist of a compressor cuff containing of an inflatable rubber bladder enclosed in an inelastic covering and the pressure source consisting of a rubber hand bulb and pressure control valve. An appropriately sized cuff should cover 2/3 of the biceps; its bladder should be long enough to encircle >80% of the arm and should have a width that equals at least 40% of the arm’s circumference. Children require smaller cuffs and obese individuals require larger cuffs. The use of an inappropriately sized cuff may lead to erroneous BP measurements (Table 3). The deflated compression cuff is applied snugly around the arm. The lower edge of the cuff should be 2-3 cm above the ante-cubital fossa. The radial pulse is palpated while the compression cuff is inflated to about 30 mm Hg above the pressure at which the radial pulse is no longer palpated. The cuff is then deflated at a rate of 2-3 mm Hg per heartbeat. The level of pressure at which the pulse in the radial artery returns is noted and recorded as the SBP. The DBP is the pressure recorded when the sounds disappear. Abnormal blood pressure reading may be attributed to several patient factors; technique errors as well as the type of device being used (see Table 3). One should avoid measuring BP in an arm if it has an arteriovenous fistula for hemodialysis or if lymphedema is present following a mastectomy. The clinician must be aware that BP may vary between a patient’s dominant and non-dominant arms. If you need to re-measure the BP, you should wait for 1 minute before taking the next reading. Devices A mercury-gravity manometer consists of a uniform diameter straight glass tube with a reservoir containing mercury. The pressure chamber of the reservoir communicates with the compression cuff through a rubber tube. When pressure is exerted on the mercury in the reservoir, it falls, and the mercury in the glass tube rises. Since the weight of the mercury is dependent on gravity, which is constant, a specific amount of pressure will always support a column of mercury of the same height. The mercury- gravity manometer is the most accurate of all BP devices, does not require recalibration, and is the standard for measuring BP. An aneroid manometer consists of a metal bellows, which is connected to the compression cuff. Variations of pressure within the system cause the bellows to expand and collapse. The movement of the bellows rotates a gear that turns a needle, pivoted on bearings, across a calibrated dial. Since the blood pressure recorded with the aneroid manometer depends upon the elasticity of the metal bellows, it is subject to errors inherent in the elastic properties of metals. For this reason the aneroid manometer must be calibrated against a mercury manometer at regular intervals (yearly). Automated devices are fine for use by an individual at home to monitor their BP. In the dental office however, they are often too inaccurate to be consistent. Results obtained from these devices have important clinical implications. For example, use of an inaccurate device may falsely indicate that a patient treated for hypertension is now normotensive and requires no further medication adjustment. The dental professional must understand that automated devices placed on the upper arm are less accurate than mercury- gravity and aneroid manometers. Automated devices used on wrists or fingers are even less accurate compared with those used on the upper arm. Devices for the wrists and fingers should be avoided all together in a healthcare setting. Regardless of which device is used, all must be appropriately calibrated and checked regularly for accuracy. 5 Classification and guidelines for management of high blood pressure Since 1980, the American College of Cardiology (ACC) and American Heart Association (AHA) have translated scientific evidence into clinical practice guidelines with recommendations to improve cardiovascular health. In December 2017, the ACA and AHA published Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults. This guideline is an update of the NHLBI publication, “The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure” (JNC 7) and the 2013, in which the NHLBI Advisory Council recommended that the NHLBI focus specifically on reviewing the highest-quality evidence and partner with other organizations to develop recommendations and is a comprehensive resource for the clinical and public health practice communities. The main findings of the 2017 guidelines now defines high blood pressure to be anyone with a systolic blood pressure (SBP) ≥ 130 mm Hg or diastolic blood pressure (DBP) ≥ 80 mm Hg. This means that more patients will be diagnosed with hypertension but by doing so, it may lead to improved blood pressure control and reduce cardiovascular disease (CVD) risk in these patients. There is the understanding that a small percentage of them will be asked to take medications but the majority will be recommended for nonpharmacological interventions with healthy lifestyle changes including use of the Dietary Approaches to Stop Hypertension (DASH) dietary program, weight loss, sodium reductions, increased physical activity and reduction in the consumption of alcohol. Blood pressure thresholds and recommendations are illustrated in Figure 1. Dental treatment for patients with high blood pressure Although acute adverse events associated with elevated BP are rare in the dental setting, some degree of treatment modifications may be needed for the patient with a history of HTN. These considerations include stress and anxiety reduction, determining possible drug interactions with anesthesia or medications the dentist may use and having an awareness of drug adverse effects and knowledge on how to manage them (Tables 4 and 5).