Measuring blood pressure

(To our junior colleagues and students) 

1. Patient should be comfortable, lying or sitting with the arm supported. Actively holding the arm up by the patient raises blood pressure. The patient should avoid smoking or drinking coffee or tea shortly before measurement as this may raise blood pressure.

2. Mercury sphygmomanometer is reliable. Aneroid sphygmomanometer is reliable if calibrated against a mercury one.

3.   Apply the cuff neatly around the upper arm well above the cubital fossa (to leave a place for the stethoscope). Any of the two arms may be used. However if the pressure is measured for the first time, especially in an elderly patient, it is advisable to measure it in both arms and consider the higher one as the true representation of the patient’s blood pressure. It is not uncommon, especially in elderly people, to get a lower reading in one arm as a result of atherosclerosis in the arteries supplying that arm. Subsequent measurements in such a patient should use the arm with the higher pressure.

4. The arm should be at the same level as the heart. The pressure inside the brachial artery decreases when the arm is raised and increases when it is lowered. The position of the sphygmomanometer is not important because the cuff and the tubing are filled with air and the pressure in a container filled with gas (unlike liquid) is the same at any point regardless of its position.

5. If you find (more often in women) that rolling up the arm clothing will constrict the upper arm and it is not practical to ask the patient to undress, then it is better to apply the cuff over the clothing provided it is not thick. Thin clothing does not significantly impair transmission of pressure from the cuff to the arm or transmission of sound from the arm to the stethoscope.⁽¹⁾

6.  It is advisable to develop the habit of measuring blood pressure by palpation first. It has the following advantages:

a)      It gives an idea about the systolic pressure so that when you take it by auscultation you only raise the pressure to a little above the systolic before starting to deflate. In this way you avoid raising it too high which is painful and may result in a reflex rise of blood pressure.

b)      It avoids the possibility of raising the pressure in the cuff to a point in the silent gap (in patients who have a silent gap) and starting deflation. You will then wrongly consider the reappearance of sounds (phase three Korotkoff sound) as the systolic pressure.

c)       It makes you check the pressure twice which is advisable. The second measurement has been found to be generally lower than the first and more representative of the real.

7.     Apply the stethoscope over the brachial artery in the cubital fossa and avoid inserting it between the cuff and the arm. The hard structure of the stethoscope may interfere with the even distribution of pressure on various points of the arm circumference.

8.  Deflation of the cuff should be slow to give time for the mercury column or the dial pointer to change position as the pressure drops. Too rapid deflation gives a higher reading as a result of inertia of the mercury or the pointer causing it to lag behind the decreasing pressure inside the cuff.

9. Diastolic blood pressure (as measured intra arterially) falls between phase four (sudden muffling) and phase five (complete disappearance) of Korotkoff sounds but nearer the latter. So it is better to take disappearance of sounds as the diastolic pressure except in the occasional case when the sounds persist down to a very low level or zero.

(1) Hovsrpian R.,  Al-Haddad M.,  Abdulla K., Comparison of blood pressure measurements in bare arm, clothed arm and forearm,  J. Fac. Med. Baghdad, 1996, 38, 221-224.

Why Iraqi doctors should be interested in research

In spite of the various research difficulties described in the previous article (Why Iraqi doctors are not interested in research), Iraqi doctors should, in my opinion, be interested in research for the following reasons:

1.     Answers to local problems:

Local research even if it is a simple survey sheds light and may produce answers to some local problems. It does not have to produce important discoveries on a worldwide scale. After all, among the huge amount of research published in thousands of medical journals worldwide, very few constitute really important discoveries.

2.     Experience for the future:

With time, research experience accumulates and results are likely to improve.

3.     Education:

Research is highly educating. Knowledge is gained by reading and discussing the subject of research and related subjects. The researcher also learns the ways of obtaining knowledge like searching the internet and using the library.

4.     Promotion of scientific and critical thinking:

By following the scientific method of making a hypothesis, collecting data and modifying the hypothesis, research promotes scientific thinking. The researcher learns how scientific knowledge is obtained and realizes that so called scientific facts are in fact hypotheses with various degrees of convincing power. They are not certainties and that is why they keep changing. This develops in him a skeptical and questioning mind which is important not only in research but also in practice and in life in general. Knowing how various workers frequently differ about the same subject is a warning that one should not take everything he reads in a book or a journal or hears in a lecture as established facts.

5.     Reflection on practice

a.     The scientific method is not confined to research. It should be the basis of practice too. In fact the clinician is involved in research daily by trying to make a diagnosis of his patient’s illness and find solutions for his problems. Fever in a patient, for example, is a scientific problem. A hypothesis about its cause should be made after the initial information. Data is then collected through history taking, physical examination and various tests to strengthen or modify the hypothesis once or more times. Actions are then taken on the basis of the final hypothesis. This is what the scientific method is all about.

b.     Awareness of observer error and observer bias, common precautions in research, is reflected on interpretation of clinical findings and various tests made during daily work.

c.      Awareness that association is not necessarily causation, a common precaution in research, reflects on clinical work. Jaundice in a patient with a positive hepatitis virus BsAg is not necessarily caused by hepatitis B virus.

d.     Knowing how reference values are obtained makes interpretation of patients’ figures more intelligent. You may e.g. accept a figure slightly outside the reference range because you know that 5% of normal people are so.

e.      Research improves logic and shows its limitations. Treatment of various illnesses is based on trials done on a number of patients somewhere in the world and the results are generalized to include all patients all over the world (induction in logical terms). Why should your patient behaves in the same way as those patients?! In fact induction is the logical basis of most medical knowledge, not only treatment. One should therefore not be surprised to find so many differences between practice and the book. What should be surprising is the presence of so many similarities!

Why Iraqi doctors are not interested in research

Iraqi doctors are generally not interested in doing research. Many have a negative attitude towards it and argue that:

1.  Time spent in research is better spent in patient care.
2.  In our poorly developed situation, research is unlikely to produce significant results. Important discoveries have been made and can only be made in developed countries that have the facilities and the expertise.

These are some possible reasons for the lack of interest and the negative attitude:

1.      Lack of experience:
Most doctors lack the necessary experience:

a.       They were not involved in research during their training, unlike doctors in developed countries who get involved in research done by those who supervise their training.

b.      Most professional postgraduate degrees in clinical branches, including those from developed countries, do not include research in their requirements. (There are exceptions like the certificate of the Iraqi Board of Medical Specialties.)

c.       Earlier education in Iraq in primary and secondary schools is generally based on memorizing (one of the Arabic words commonly used to mean study is “istithkar أستذكار” which means remembering). Thinking and reasoning do not have prominent roles. The student becomes used to accepting what he is told rather than developing a skeptical exploring mind which is the basis for research.

2.      Lack of time:
Doctors are usually busy people. Their time is occupied by care of patients in government institutions and in private practice.

3.      Lack of incentive:

a.       Research is not financially rewarding.

b.      Except in universities, it does not promote the position of the doctor in the place where he or she works.

c.       Most of the problems in medical practice in the country are not medical. They are administrative, political, cultural and financial. These are less likely to be solved by medical research.

4.      Difficulties in research:

a.       Research is time consuming and mentally demanding.

b.      Technical facilities (laboratories, radiology etc.) in our hospitals and medical institutions are not satisfactory.

c.       There is no good medical record keeping and good follow up of patients.

d.      Good libraries and references are not widely available.

e.       There is no sufficient funding for research.

f.       Cooperation of patients and non medical people is generally poor. Importance of research is not widely recognized in our culture.

g.        Animal research is not generally available except on a very limited scale in universities.

h.      Ethical and legal restrictions on research on humans are not well defined and properly legislated and not carefully observed. This can create problems which may sometimes be serious.

Readers may be able to add other reasons that I may have missed.