Blog on clinical tips

I shall share my ideas and thoughts on clinical tips which I find useful.

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Clinical tips for junior health professionals

 

This blog is likely to be useful to medical students and junior doctors. I may mention cases in brief based on actual patients I have encountered. Details of patients are deliberately withheld.

 

Read through my latest blog posts and feel free to comment on them if you like.

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Commonest important cause of calf swelling is DVT (deep vein thrombosis). Left untreated, there is a risk of pulmonary embolism which can be fatal.

 

Others causes are:

Cellulitis

Trauma

Compartment syndrome

Necrotising fasciitis

Ruptured Baker's cyst

Ruptured gastrocnemius muscle

Ruptured popliteal aneurysm

 

How not to diagnose hypopituitarism

Posted on 28th December, 2013

75 Male, admitted with hypothermia. History of hypothermia once before as well.

 

Blood results on admission:

Random Cortisol 655 (N)

FT4 11.5 (low), TSH 3.48 (normal) - inappropriately normal TSH.

 

Two days later, SST:

Basal Cortisol 257, 30 min post-synacthen 891 - normal response.

 

Someone started him on Thyroxine and Hydrocortisone - Hypopituitarism!

 

He had another set of blood tests before the patient taking Thyroxine and Hydrocortisone:

Cortisol 484 (N), FT4 13.8 (N), TSH 2.50 (N), Prolactin 241 (N)

Testosterone 5.0 (low), FSH 42.3 (H), LH 23.7 (H)

 

We stopped Thyroxine and Hydrocortisone as he does not have Hypopituitarism.

Reasons:

Normal SST, so no adrenal insufficiency. If there was hypopituitarism then SST would have shown impaired response. Adrenal glands to function normally, they need to be constantly primed by ACTH from pituitary gland.

Initial low FT4 with normal TSH could be due to Sick euthyroid syndrome.

Plan : Repeat FSH LH Testosterone after 1m at 9 am. He may have underlying Primary hypogonadism and may benefit from Testosterone replacement which improve muscle mass that may have contributed to his hypothermia.

 

Comment:

In Endocrinology, do the imaging only after establishing the biochemical abnormality. Otherwise you may end up with Incidentaloma.

Repeat abnormal tests if necessary.

Proper interpretation is important before subjecting the patient to lifelong hormone replacement.

Thromosis in the arteries lead to heart attack, stroke, gangrene etc.

 

Thrombosis in the veins lead to DVT, Cerebral vein thrombosis, Hepatic vein thrombosis, Renal vein thrombosis etc.

 

Thrombus in the faster-flowing blood vessels like arteries are composed mainly of platelets with little fibrin.

 

Antiplatelets like Aspirin and Clopidogrel reduce platelet aggregation and inhibit thrombus formation in arterial circulation in which blood flows quite fast.

So, antiplatelets are used in prevention of heart attack, stroke and gangrene in PVD.

 

To prevent thrombus formation in slow-flowing blood vessels like veins, the thrombus has more fibrin, so that antiplatelets are not so effective. Here you have to use anticoagulant like Warfarin.

 

Clopidogrel is stronger than Aspirin. Clopidogrel is used to keep coronary and other vascular stents patent.

 

Anticoagulation is also needed to prevent thromboembolism in AF, CCF, atrial dilatation, ventricular aneurysm, akinesia, hypokinesia etc.

 

If anticoagulation is problematic, then Aspirin and Clopidogrel together can be used to prevent thromboembolism in AF.

 

The above are suggestions only.

Please keep up to date with current practice and follow local guidelines.

Hyponatraemia – a simple approach to management

Posted on 18th September, 2013

Hyponatraemia is a very common clinical problem. Many are left with the diagnosis of ‘Chronic hyponatraemia’.

 

Following advice is for junior health professionals only. I shall keep it brief.

 

Tests: Order these only if no improvement on stopping the offending agent like diuretics, ace-inhibitors with fluid restriction 1 L/d if U&E normal. Can wait 2-3 days if Na >110:

 

Morning cortisol, TSH.

U&E

Serum osmolality, urine osmolality.

Urine Na & K

 

Management:

If Na >125 – stop offending agent. Restrict fluid 1 L/d if U&E - N.

 

If dehydrated – N Saline IV.

 

Morning cortisol, if low – SST etc. for Addison's disease.

 

TSH high – T4 replacement for hypothyroidism.

 

If Urine Na>40 with K high as well, then try Slow sodium 600mg qds to start with.

 

SIADH : Hyponatraemia with normal renal adrenal & thyroid functions, no dehydration or oedema.

Na <133, S. osmolality <270 U&E - N

Urine osmolality > S. osmolality. I prefer >twice the S. osmolality or at least >500.

Urine Na >40

 

Treatment of SIADH: fluid restriction 1 L or 500mls per day. May need Demeclocycline.

 

Above are my suggestions only. Follow your local practice. Consult endocrinologist if needed.

Rarely Type1 diabetics may develop Addison's disease due to autoimmune destruction of adrenal glands.

Type1 diabetics are routinely checked for Addison's disease, Coeliac disease and Thyroid disease in annual review by checking 9 am cortisol, TTG antibody and TSH.

 

When to suspect:

- frequent unexplained hypos

-reduced insulin requirement

-nausea vomiting diarrhoea weight loss dizziness postural hypotension etc

-low sodium

-high potassium

 

Do not give hydrocortisone unless patient is in Addisonian crisis.

Initially, 9 am cortisol should be checked. If absolutely or relatively low, then will require SST.

9 am cortisol less than 200 will usually need SST.

Practices vary. Check with your biochemistry department.

 

Watch out for diabetes in the elderly

Posted on 14th June, 2013

About 10% of people over the age of 65 develop diabetes. This is due to impaired beta cell function and exaggerated insulin resistance that occurs with ageing.

 

Glycosuria may be delayed due to rise in renal threshold for glucose with ageing. So, urine testing may not be as useful to diagnose diabetes early.

 

Pancreatic carcinoma may present with diabetes in old age associated with weight loss and anorexia.

 

Now a days, because of multiple comorbidity and increased longevity, people frequently attend hospital or doctor’s surgery. Blood glucose testing during these visits will help in the early diagnosis of diabetes in the elderly.

 

Sometimes the CXR appears normal, but on close scrutiny the following conditions may be found:

 

Apical pneumothorax

Tracheal compression - retrosternal goitre, lymph nodes

Absent breast shadow (mastectomy) – breast cancer

Ribs – fractures, metastasis, notching (Coarctation of aorta)

Gas under diaphragm – perforation of viscus

Double left heart border – LLL collapse

Fluid level behind the heart – Achalasia

Paravertebral abscess

Pneumomediastinum – air around heart border

 

So, look carefully before you declare the CXR as normal.

 

White patches on skin can occur in both vitiligo and tuberculoid leprosy.

Vitiligo occurs due to autoimmune destruction of melaonocytes in the skin whereas Leprosy results from infection with a bacteria called Mycobacterium leprae.

 

People with vitiligo are otherwise well but they are at risk of developing other autoimmune diseases. Treatment is rather unsatisfactory.

 

Untreated leprosy results in deformities, neuropathic ulcers etc. It spreads by prolonged close and intimate contact. Treatment is with Dapsone Rifampicin etc.

 

That is why it is important to know the differences in the white patches in these two diseases.

 

Vitiligo - symmetrical pearly white patches, hairs may become white as well but sensation is normal, hairs do not fall of, sweating is normal. Patch is not raised.

 

Tuberculoid leprosy - asymmetrical white patches, not pearly white, hairs are black and they fall off, loss of sensation of touch pain heat and cold and loss of sweating in the area. The patch may be raised from rest of skin.

 

Read more about Vitiligo

 

Bowel perforation presenting as chest pain

Posted on 14th March, 2013

Abdominal pain can be caused by chest problems and chest pain can be due to abdominal conditions.

 

I shall describe a case of bowel perforation presenting as chest pain:

58 year old lady presented to casualty complaining of chest pain.

Her ECG shows widespread t wave inversion - nonspecific T wave changes. Triple test negative.

 

On probing, she denied exertional chest pains.

 

Went to see the chest xray - it shows lucency under both hemidiaphragms. But she did not complain of significant abdominal pain, nausea or vomiting.

 

On examination of abdomen, it was soft, slightly distende, not much of tenderness. Bowel sounds were rather sluggish.

 

Sometimes colon can be interposed between right hemidiaphragm and liver which may look like perforation. But it was on both sides.

 

We wanted radiologist's opinion as clinically it was not an 'acute abdomen'. He agreed that indeed it was bowel perforation but may have happened few days ago.

She went to the surgeons and was operated on.

 

Learning point: If it is not clear cut, then look for alternative explanation of chest or abdominal pain.

Treatment in a case of chronic hyponatraemia

Posted on 22nd February, 2013

Do not sit on the diagnosis of chronic hyponatraemia. See what can be done about it.

 

I shall describe a case.

78F

05.02.13 Na120 K4.5 U6.1 Cr 43 Plasma osmolality 253 low. ?SIADH - Put on 1L/d fluid restriction.

07.02.13 Na 124

12.02.13 Cortisol 597 TSH 0.86 Na126 Posm. 259

Urine osmolality 230 Urine Na 59

15.02.13 Slow sodium 2tabs bd

18.02.13 Na 130

 

Interpretation:

Cortisol - normal, not Addison's disease.

TSH - normal, not hypothyroidism.

Not on any drugs that can cause hyponatraemia - so, not drug-induced.

Low plasma osmolality with urine osmolality lower than plasma osmolality - not SIADH.

No oedema - not sodium overloaded.

High urine Sodium.

 

Diagnosis - Renal salt wasting

 

Treatment - Fluid restriction 1L/day.

Slow sodium 2 tabs bd

Na came up to 130 in 2 days - patient discharged.

 

Follow up - when Na normal, allow free fluids.

May need adjustment to the dose of Slow sodium later.