Patient Assessment--Factors Affecting Medication Response
Proper Patient Assessment before any treatment and medication administration is vitally important:
- Ethnic background
- Physical health
- Psychological status
- Environmental temperature
- Amount of food in stomach
- Dosage form
Assessing Patient Vital Signs:
Vital signs traditionally consist of blood pressure, temperature, pulse (heart) rate and respiratory rate. In a
medical office it is an important component to monitor every patient before and after a medication is administered.
This task is usually assigned to the medical assistant and includes neonatal, pediatric, and adult patients. The
equipment needed is a thermometer, a sphygmomanometer, and a watch. Though a pulse can often be taken by hand, a
stethoscope may be required for a patient with a very weak pulse. When observing a patient accuracy should
not be taken for granted!!! Any degree of inaccuracy resulting from incorrect technique leads to:
- False readings
- Unnecessary treatment
- Inappropriate treatment and follow up
Remember: Only a medical assistant who is aware of the
factors that lead to false readings should measure blood pressure. Inaccurate readings obtained through
failure to use the proper technique lead to the wrong diagnosis, which may result in unnecessary or
inappropriate treatment and follow up.
Blood Pressure Screening
The National Heart, Lung, and Blood Institute (NHLBI) guidelines defines normal blood pressure as follows:
- Less than 120 mm Hg systolic pressure and
- Less than 80 mm Hg diastolic pressure
Obtaining a Blood Pressure Reading:
- Instruct patients not to use tobacco or caffeine for 30 minutes before the measurement is
- Seat the patient in a quiet environment, free from temperature extremes, for at least 5 minutes before the
measurement is performed.
- Perform the measurement with a mercury sphygmomanometer, if available. An aneroid manometer may be used if
it is periodically calibrated according to manufacturer's recommendations. A validated electronic device
meeting the requirements of the American National Standard for Electronic or Automated Sphygmomanometers set
forth by the Association for the Advancement of Medical Instruments may also be used.
- Position the manometer at eye level, if possible, to assure accuracy in reading the measurement.
- Use an appropriately sized cuff. The bladder of the cuff should encircle 80% to 100% of the arm.
The cuff width should be 40% of the circumference of the upper arm. Use of narrow cuffs leads to falsely
elevated readings. Use of wide cuffs may falsely lower the reading.
- The patient's arm should be bare; avoid constricting the upper arm with a rolled shirt sleeve.
Support the arm horizontally so the cuff is positioned at heart level (the fourth intercostal space).
- Apply the stethoscope lightly to the antecubital fossa. Excess pressure results in falsely low diastolic
blood pressure readings.
- Rapidly increase cuff pressure to about 30 mm Hg beyond the point at which the radial pulse is no longer
palpable. Decrease pressure at a rate of no more than 2 to 3 mm Hg per second.
- In adults, the measured systolic blood pressure (SBP) and the diastolic blood pressure (DBP) readings are
the pressures corresponding to the first of two consecutive sounds and the disappearance of sound (not
muffling), respectively. Confirm the disappearance of sound by continuing to listen while decreasing pressure
10 to 20 mm Hg below the last sound heard.
- Use the average of at least two readings unless the first two differ by more than 5 mm Hg, in which case
obtain additional readings. To permit blood to be released from arm veins, allow an interval of 1 to 2 minutes
before repeating pressure measurements in the same arm.
- Measure blood pressure in both arms initially; at subsequent visits, remeasure using the arm with the
higher initial pressures.
- Confirming the diagnosis of hypertension requires high blood pressure readings during at least two
subsequent visits (unless SBP is 210 mm Hg or higher, DBP is 120 mm Hg or higher, or both).
Because blood pressure readings obtained in a medical setting may not be typical of a patient's usual
blood pressure, monitoring at home or work by the patient, family, or friends may be valuable.
Measurement devices must be calibrated initially and rechecked at least yearly. Instruct the person
taking the blood pressure in proper technique, and recheck the technique periodically.
Source: Clinician's Handbook of Preventive
Services, 2nd Edition, produced by the U.S. Department of Health and Human Services, is a
practical and comprehensive guide to clinical preventive services including screening tests for
early detection of disease, immunizations and prophylaxis to prevent disease, and counseling to
modify risk factors that lead to disease.