Geriatric Medicine for Old-Age Psychiatrists

Alistair Burns, Michael Horan

• Publisher: CRC Press
• Year: 2005
• Print ISBN: 9781841843933
• eBook ISBN: 9781135409654
• Topic: Medicine
• Subtopic: Psychiatry & Mental Health

This up-to-date digest of current medical problems will aid the reader in interpretation of investigations, which are increasingly requested. It provides guidance for the first line of management of patients. It is written primarily by an experienced geriatrician, informed by an old-age psychiatrist; a unique combination of author perspectives that

1
Introduction

MEDICINE IN OLD AGE

The practice of old age psychiatry differs from general adult psychiatry, not least because of the particular attributes of the patients presenting with psychiatric disorders. The most obvious difference is that the patients are old and will be well advanced along the trajectory of numerous age-related changes. Aging processes, at least in the biological sense, are relatively benign and are seldom manifested in the absence of some additional stressor. Indeed, we can usefully consider aging to be a progressive erosion of reserve capacities and an increased susceptibility to the effects of external stressors. As a rule of thumb, those under the age of 70 years will be physiologically similar to middle-aged people, whereas those over 75 years will show an increasing likelihood of age-related impairments.

Whether we consider it to be age-related or simply time-related, older people are also characterised by the accumulation of various, usually chronic, diseases. This phenomenon is often referred to as co-morbidity (or less accurately as multiple pathology) and is highly characteristic of older people. These co-morbid factors may have significant health and survival implications in their own right, but they will also frequently complicate the assessment and/or management of older people presenting with psychiatric disorders. In some instances, such as delirium, the psychiatric disorder may be a very direct consequence of the underlying physical disturbance. Thus, any practitioner in old age psychiatry must have a working knowledge of aging physiology, how drug handling and drug actions change in old age and the common somatic disorders of older people. They need to know what they can reasonably manage without the help of a physician (or sometimes, a surgeon) and also what is foolhardy for them to attempt to treat without such help. The following chapters are concerned with understanding the relevant physiology and the management of common medical problems. Where appropriate, guidance is given about how to treat these medical conditions; where inappropriate, we also suggest what information a physician or surgeon may want in order to make an assessment.

THE PRESENTATION OF DISEASE IN OLD AGE

The classical presentations of diseases given in popular textbooks will certainly be encountered in the medicine of old age. Some old people with a myocardial infarction do have crushing central chest pain radiating to the neck and arm and associated with nausea and vomiting (but not always!). However, less clear-cut presentations of many diseases are the rule rather than the exception. Four general modes of presentation can easily be recognised:

(1) Typical;
(2) Atypical;
(3) Silent;
(4) Pseudo-silent.

Descriptions of typical (classical) presentations can be found in any standard medical textbook and are not described further here.

Atypical presentations generally arise from interactions between aging and co-morbid factors, so that dysfunction in one organ or system can give rise to the dominant presenting symptoms and signs being manifestations of dysfunction in some other organ or system. Thus, delirium can be the presenting feature of almost any disease or disorder in older people. Some presentations are so common as to account for the majority of the clinical practice of most geriatricians. One of our great geriatricians, Bernard Isaacs, referred to them as the five ‘I’s’:

(1) Immobility (reduced activity and functional ability);
(2) Instability (falls);
(3) Insanity (delirium);
(4) Incontinence;
(5) Iatrogenic (caused by something a doctor has given).

To these, Kane has added a lot more ‘I’s’ of geriatric medicine (see Table 1.1).

These atypical presentations can be extremely challenging to sort out, and demanding of considerable experience and diagnostic acumen.

Silent presentations are rather less common than typical and atypical ones, but they do occur. Very often, the patient is ‘not right’, ‘unwell’ or ‘not

Table 1.1 The ‘I’s’ of geriatric medicine

themselves’, or has taken to bed. Beware especially the patient who says that they are about to die: it is not unusual for them then to do so (most often of a pulmonary embolus or massive haemorrhage). Silent presentations can be even more challenging to the doctor than atypical ones.

Pseudo-silent presentations are all too common: they represent a failure! They arise because a doctor is too inexperienced, lacks the necessary knowledge, gives up because it is just too difficult or simply can not be bothered. We provide you with enough information in the following chapters to avoid this trap. To paraphrase Einstein, ‘Everything will be made as simple as possible, but not one bit simpler.’

THE MEDICAL APPROACH: THE CAREFUL DOCTOR

Most experienced physicians do not follow the logical standard we all learned in medical school: they tend to rely on wide experience and a good memory from which they have constructed patterns or templates against which they apply new pieces of information as they emerge. The subsequent approach is to seek further information to confirm or refute possible diagnoses. This approach is both effective and efficient, although it sometimes gets the diagnosis spectacularly wrong. Do not be surprised when an experienced physician solves a problem in a few minutes that you have grappled with for days (or longer): that is what he (she) is trained to do. Experienced surgeons are similarly capable. This is well illustrated by an anecdote about Walter Edward Dandy, an American pioneer of neurosurgery of Lancashire parents. He reviewed a patient, already anaesthetised, whose diagnosis had puzzled several of the physicians. Dandy immediately recommended a right-sided trepanation to drain the so-far undiagnosed brain abscess that he thought was producing the symptoms. As the pus drained, an amazed observer asked Dandy how he made the diagnosis and knew where to drill the trephining hole. Dandy replied ‘God must have whispered in my ear.’

This approach works for the management of problems too, just as it does for diagnosis. Most experienced physicians know what is likely to happen if a particular treatment is given and how long it might take before it happens, so they have an intuitive grasp of when something is not quite right, which prompts a re-evaluation of the patient. We can not teach you this sort of experience, but we can present some general rules to avoid getting into difficulties worse than the presenting problem.

SOME GOLDEN RULES

Diagnosis

Always check some critical piece of information before acting on it. For example, check the blood pressure measurement yourself. Look at the ‘sweat rash’ reported by the nurse who is asking you to prescribe Canesten^® or Timodine^®: it may be, for example, a squamous carcinoma which will respond much better to surgery or radiotherapy. What you are told is a sacral pressure sore may actually turn out to be perianal Paget’s disease, lichen sclerosus or Crohn’s disease. Do not blindly accept the interpretation that someone had an epileptic seizure: get a description of exactly what happened. Some words, such as collapse, do not have any precise meaning: it can refer to a fall, presyncope or unconsciousness: always check what the informant means.

Investigation

Investigations should generally be used to test diagnostic hypotheses and not to generate them. However, screening investigations do have a role in the medicine of old age. However, be aware that if you perform enough tests, you will eventually find one or more that falls outside the normal range, and you will then have orphan data in search of a hypothesis. One wag defined a normal person as one who has not been sufficiently investigated. We would suggest the screening tests listed in Table 1.2 as suitable for this purpose when you encounter a new patient. These tests need doing only once: other tests or repeats should be performed only to answer specific questions. If you do request any investigations, you must look at the results. Any urgent radiographs must be sent for reporting by a radiologist.

The first question you should ask yourself is whether or not you know how to interpret the tests you are requesting. If you do not know, you should either find out or not perform the test. Even if you do know how to interpret a test, you do not necessarily have to perform it. Apart from the oneoff screening tests suggested, you should ask the following questions:

Table 1.2 Suitable screening tests

---

Full blood count (FBC)

Biochemical profile

urea and electrolytes

glucose

liver function tests

albumin and globulins

calcium

Thyroid function tests

T₃

T₄

TSH*

Blood lipids (optional)

ESR (but difficult to interpret)

Urine stick testing (including blood, protein and nitrite)

Some psychiatrists recommend the following tests in the setting of cognitive impairment, although there is little evidence to support this:

Vitamin B₁₂

Folic acid

Syphilis serology

---

* Some laboratories measure only thyroid-stimulating hormone (TSH) for the purpose of screening; T₃, tri-iodothyronine; T₄, thyroxine; ESR, erythrocyte sedimentation rate

(1) What will you do if the test is positive?

(2) What will you do if the test is negative?

If the answer to these two questions is the same, there is no indication to perform the test.

Prescribing (see Chapter 6)

Before prescribing a drug, decide what you expect the drug to do. Also, set a time when you will review whether or not it has done this. If your goal has not been achieved, it is most likely that the diagnosis was wrong or you have selected the wrong treatment. Whatever the explanation, you must seek it.

If you prescribe a drug, you must know what side-effects the drug might have and any important interactions. Later in the book, we address the topic of therapeutics in more detail, and we summarise common side-effects of the most frequently used drugs. When you are prescribing, try to stick to the drugs that you know and you will prescribe them safely. Also, make sure that you are aware of any local guidelines and policies relating to problems you commonly encounter. If you must prescribe a drug that you do not know, ensure that you check an up-to-date copy of the British National Formulary (BNF) for important side-effects, interactions and any dose adjustments recommended for older patients.

Get into the habit of reviewing drug charts regularly. What is the indication for each of the drugs? Anticonvulsants and antidepressants have uses other than their main ones (pain, for example). Are all the drugs still indicated? Could the problem that you are addressing at the moment be caused by a drug or drug interaction? Have the prescribed drugs actually been given to the patient and has the patient subsequently ingested them? Never increase the dose of a drug without being sure that the previously prescribed dose has been given and ingested!

Management

Many older people will already have multiple diagnoses and some of them may not be well established, or they may even be wrong. Diagnosing a condition does not necessarily mean that it needs treatment. Most people taking more than seven drugs will have new problems caused by the drugs (or interactions), and they will probably not be taking them as prescribed in any case. However, we have encountered one patient taking 38 different medications, some for the side-effects of already prescribed drugs. Regrettably, she was taking them all exactly as prescribed: her husband had taken early retirement to supervise the medication schedule. The drugs killed her!

Most practitioners of medicine in old age are more concerned with problems and problem management rather than simply with diagnoses. For both investigation and treatment, list the problems and consider which are stable/unstable, active/inactive. Consider which are the most straightforward and most troublesome and concentrate on those. Worry about the remaining ones at some other time, but do not forget about them.

Loeb’s Laws (points 1–3 below) probably constitute the most sensible advice for practicing medicine:

(1) If what you are doing is working, carry on;
(2) If it is not working, stop;
(3) If you do not know what to do, do not do anything (other than seek help);
(4) Do not try to be too clever (our addition).

Most patients will have simple, straightforward things wrong with them and not rare conditions. Learn the common disorders and then you will know when something does not quite fit. You can then look it up or seek help. Trying to be too clever can get you into trouble. Most doctors will not see more than one case of infective endocarditis during an entire professional lifetime; they will see lots of respiratory infections, urine infections and skin infections. Rare presentations of common conditions are much more common than rare disorders, even common presentations of rare conditions. However hard we try, we will make more misdiagnoses of obturator hernia than correct ones, mainly because the prior probability of this diagnosis is low. You will only recognise what you know, so make sure you know the common things.

2
History and physical examination

THE BASIC MEDICAL HISTORY

You will be seeing patients whose primary problems are psychiatric ones. However, always remember to check whether the patient has any other problems that they think you need to know about. If the patient volunteers any, you need to ask further detailed questions about them. Thereafter, screening questions will uncover problems in the major organs and systems. Table 2.1 gives a list of useful questions organised around function. This is an approach used by one of us when screening patients in the orthopedics and trauma wards: it not only uncovers problems but also indicates how severe the problem is and how it impacts on someone’s life. When positive answers are found, clarification and relevant p...

Table of contents

• Cover Page
• Title Page
• Copyright Page
• List of contributors
• Preface
• 1 Introduction
• 2 History and physical examination
• 3 Interpretation of abnormal results
• 4 Clinical management
• 5 Clinical vignettes
• 6 Commonly prescribed drugs
• 7 Further reading
• 8 Appendix