61 year-old lady with a history of Alzheimer’s dementia develops shortness of breath and coughing.
Her husband explains that she became rather vague and unusual during the last 4-5 days; her speech is incoherent with some rambling and irrelevant chatting, which come and go. She also has difficulty focusing and has become very lethargic.
The patient developed pneumonia twice over the last 2-3 weeks. Her past medical history is significant for hypertension and depression for which she takes vals
artan and paroxetine, respectively. She smokes cigarettes and drinks no alcohol.
Bloods for haematology and biochemistry are shown.
What's going on?!!
NB. please note normal values for lab parameters:
Hb (11.7-15.7), MCV(80-99), WBC (3.5-11), Platelets (150-440), Na (135-145), K (3.5-5), Urea (2.5-6.7), Creatinine (70-120). Glucose (4-6), Albumin (35-50), plasma osmolality (275-295), urine osmolality (rang
e; 100-1000).
CLINICAL LESSONS;
1/ be able to differentiate confusion from dementia using CAM
2/ Be able to recognize SIADH - it is suggested by dilutional hyponatraemia with
my thoughts are that your patient's azheimer's is becoming worse since it eventually do progress! and cough and SOB are caused by a chest infection.may be such patients are more prone to chest infections! but looking at the lab results - i see anaemia. so hmm, iron deficiency is the most common one! there seems to be lots of positives and i don know whether these are just red herrings!!
ReplyDeleteAyoub can you post the normal lab values? Can't be bothered to look them up :)
ReplyDeleteThis is like a Board question but without choices. Let me think about it and I'll get back to you.
ReplyDeleteSIADH caused by either the pneumonia or more likely the paroxetine if im not mistaken.
ReplyDeleteGood case btw ... keep it up !
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteThis is a complex clinical situation where multiple clinical events has occurred on the background of chronic ill health. However, these scenarios are not uncommon especially in old age. It also provides the ideal environment for the examiner to test your diagnostic skills and your ability to form a differential diagnosis. So it's good practice to summarize the observations, identify the chronological order of the events and form a differential.
ReplyDeleteThe importance of listing the differential is so that we don't miss an alternative cause.
Here are more information;
1/ On examination;
- patient appears pale, normal vitals except for tachypnoea,
- pale conjunctiva
-Right-sided deviated trachea. reduced chest expansion,
-Dull percussion note, reduced breath sounds and reduced vocal resonance
CVS and Abd exams are unremarkable.
2/ the first commentator raised a very important question; What is the cause of patient's recent mental deterioration? is it the product of a worsening dementia? or not? and why;)
3/ syndrome of inappropriate ADH secretion (SIADHS) is a good 'guess' - but could you explain why?
So - could you please give a differential, a working diagnosis which could explain the whole clinical picture, and suggest how would you proceed next (i.e. What is the next appropriate action having got a rough idea of what's causing patient's symptoms and signs)?
Since we have to always justify our clinical decisions in the real world, this puzzle is meant to encourage your logical problem-solving skills. Imagine you're an attorney having to convince a jury that a suspect has committed a crime- so you need to present the evidence and ask for more?! ;)
In order to stimulate a real-life scenario, I will provide more clinical information and data on progress of our patient as you give more responses! more information of investigations will be provided upon request!
The case is selected so that the topics covered have direct relevance to OSCEs and MCQ papers + general clinical skills:))!
Acut worsening of mental state in elderly is always a serious matter.
ReplyDeleteIn your case:
the cause of her acute confusion is mainly due to her chest infection and Hyponatremia.
She need to be admitted to hospital to stop her anti-depressant (the likely cause of her hyponateremia) and to correct her fluid and menerals , also her chest infection need to be investigated to rule out neoplasm or emphysema especialy that she is a a smoker.
I appreciate your feedback
Dr. Bo-Meshary
Thanks and sorry for the late reply!
ReplyDeleteThe primary diagnosis is bronchial carcinoma complicated by lobar collapse, pneumonia and SIADH.
The patient had 2 main categories of clinical features; 1/respiratory 2/mental
1.RESPIRATORY
Recurrent attacks of pneumonia indicate an underlying lung pathology. Small cell carcinoma is strongly associated with smoking and hence represents a likely candidate, particularly in the presence of hyponatraemia. This type of lung cancer include a population of cells called 'oat cell's, which make and secrete neuropeptides such as ADH and ACTH hence causing SIADH or Cushing's syndrome, respectively.
Tracheal deviation to the side which sounds stony dull at percussion with reduced chest expansion and reduced breath sounds and reduced vocal resonance are all indicative of lobar collapse. This is distinguishable from consolidation which presents with central trachea, bronchial breathing and coarse crackles.
Bronchial obstruction leads to poorly ventilated aveoli. Now the pulmonary circulation is a clever thing! it shuts blood away from these 'dead' alveoli by means of hypoxic vasoconstriction. Poorly ventilated and perfused alveoli eventually collpase.
Pallor and pale conjuctiva are signs of anaemia, which is confirmed biochemically. Normocytic normochromic anaemia (as indicated by lab results) is suggestive of cancer although not very specific. Iron deficiency causes microcytic anaemia (in reference to the first reply).
CONT'D
ReplyDeleteMENTAL
A very important clinical lesson is to distinguish dementia from confusion. Dementia is defined as global intellectual decline with memory disturbance, impairment of reasoning ability, disorientation, personality change and loss of learnt motor skills. It results from organic brain disease and is usually chronic and progressive. On the other hand, confusion occurs acutely as mentioned above by Dr BoMishari. A very useful diagnostic aid is the Confusion Assessment Method (CAM)- you need the 1st AND 2nd of the following criteria + 3rd OR 4th;
1 Acute onset and fluctuating course
2 Inattention (difficulty focusing, distractibility)
3 Disorganized thinking
4 Altered level of consciousness (classified into alter, hyperalert, lethargic/drowsy/easily aroused, stupor/difficult to arouse or coma/unarousable)
Going back to the scenario - features 1,2 and 3 were present as features of confusion which should alert the attending physician that this recent change in the mental status of the patient is not part of the dementing illness, but an independent clinical presentation of a different pathology. Hence, we can approach the problem systematically by exploring the likely causes of confusions. Electrolyte disturbances include low sodium and high calcium shouldn’t be overlooked.
In this case, biochemistry showed low sodium (hyponatraemia) – it can result from
1/ plasma diluting aetiologies (i.e. dilutional hyponatraemia) or
2/ salt losing aetiologies
This is why plasma and urine osmolalities are great to evaluate.
Plasma osmolality was reduced suggesting that we are dealing with a dilutional hyponatraemia i.e. the system is containing too much water which is diluting the salt. The kidneys are not very smart! They realize that there is low sodium in the system so they re-absorb sodium from the urine , and with sodium comes more water. So a vicious cycle leading to volume expansion occurs and the system never recovers.
Normally you’d expect urine osmolality to keep up with plasma osmolality. In this case, this didn’t happen – urine is inappropriately more concentrated as compared to plasma which is diluted. i.e. the kidney is blindly preventing water loss through concentrating urine despite the fact that the patient is ‘drowning’ in her own plasma. This is suggestive of SIADH.
So in summary, among the causes of dilutional hyponataemia (e.g. Addison’s, hypothyroidism, heart/kidney/liver failure), SIADH is more likely because of the following;
1 Low plasma osmolalitiy with high urine osmolality
2 Absence of hyperkalaemia (otherwise think Addison’s)
3 High urinary excretion of sodium (i.e. urinary Na > 30 mmol/l)
4 Renal, adrenal and thyroid functions are normal
Now having confirmed SIADH – you need to find out the causes;) which are literally everything;)
They include tumours, lung disease (eg pneumonia), CNS disease (eg meningitis), metabolic (eg alcohol withdrawal) and drugs (eg thiazide diuretics, amytriptyline (TCA)
There has been rare reports of paroxetine associated with SIADH, but this should not divert your attention from excluding a more sinister cause eg malignancy.
So The management is to
1 correct the underlying cause (ie cancer). Chest imaging to confirm malignancy is needed (CT better – cancer in x ray can be masked by infection and collapse). This will also require staging including head CT for brain mets.
2 provide symptomatic relief with fluid restriction. It corrects electrolyte abnormality in almost every case only if tolerated. If not, then you can use demecycline which inhibits ADH receptors in the kidneys allowing them to excrete water
So in conclusion, we dealt with mental and respiratory complications of lung cancer, which might have dismissed otherwise as symptoms of old age or of a progressing dementia. Small cell cancer diagnosis should not be overlooked because it usually metastasizes at a fast rate in comparison to the other types.
I hope you found it educationally useful and mentally challenging
Thank you very much Ayoub for this interesting case.. having been out of clinical for 2 1/2 years, i felt that I have revised ALL of medicine in one case!
ReplyDeleteI would just like to emphasize the seriousness of a diagnosis of small cell lung cancer. it is a nasty disease where most patients are metastasised at presentation and a 5 yr survival rate of 5%, and in some cases as low as 1%.
allah yekafeena el shar..