Your Daily Meds - 29 November, 2022
Good morning and welcome to your late Tuesday dose of Your Daily Meds.
Bonus Review: What fluid loss can occur via sweating?
Answer: Consider eccrine sweat glands as the important site of fluid loss from sweating - they are distributed over 99% of the skin surface.
They have sympathetic cholinergic innervation (muscarinic).
Maximum sweat loss can be up to 1500-2000mL per hour in extreme heat environments (up to 12L per day). And daily sodium loss in the sweat can vary from 5-350mmol per day.
Question:
Which of the following is the most common cause of anaemia in pregnancy?
Folic acid deficiency
Vitamin B12 deficiency
Iron deficiency
Alpha-thalassaemia
Sickle cell haemoglobin
Have a think.
Scroll for the chat.
Case:
Which of the following regimens is most suitable for the initial management of a hypertensive emergency?
Hydralazine 1 mg intravenous bolus
Nifedipine immediate-release 10 mg orally
Captopril 12.5 mg orally
Clonidine 100 micrograms orally
Prazosin 2 mg orally
Have a think.
Scroll for the chat.
Deficient:
Iron deficiency anaemia is the most common cause of anaemia in pregnancy, accounting for up to 90% of cases, followed by folic acid or B12 deficiency anaemia and haemoglobinopathies.
Absorption of dietary elemental iron increases in pregnancy from 10% to approximately 20%, however dietary deficiency is still a major cause of anaemia in pregnancy. Malabsorptive syndromes and excessive loss due to menorrhagia, antepartum haemorrhage and grand multiparity are also predisposing factors.
Diagnosis of iron deficiency anaemia is by hypochromic microcytic red blood cells and low serum ferritin.
Folate deficiency may be due to dietary deficiency or increased demand as in haemolytic anaemias and multiple pregnancies.
Vitamin B12 deficiency is rare in pregnancy and may be due to autoimmune pernicious anaemia, dietary deficiency or disease of the terminal ileum.
Thalassaemias are quantitative defects in haemoglobin production that affect either alpha or beta globin chains.
Sickle cell haemoglobin, seen in sickle cell disease, is a result of an autosomal recessive disorder of beta globin gene mutation.
All About the Squeeze:
Hypertensive emergency is described by severely elevated blood pressure (BP), usually above 220/140 mmHg, associated with acute end-organ damage or dysfunction. End-organ damage or dysfunction, in this context, may include acute pulmonary oedema, acute kidney failure, hypertensive encephalopathy, papilloedema or cerebrovascular haemorrhage.
Initial management of hypertensive emergency should be an initial reduction of BP within minutes, to no more than a 25% reduction in the first 2 hours. For hypertensive emergencies, an intravenous administration of hydralazine as a 1 mg bolus, that is repeated every minute as required to a maximum total dose of 5 mg, is a suitable option.
Hydralazine is a direct vasodilator at an arteriolar level with little effect on venous dilatation. It decreases systemic vascular resistance and, subsequently, blood pressure.
The other options listed, all orally administered agents, are more suitable in cases of hypertensive urgency (symptomatic elevation of BP above 180/110 mmHg).
Remember that hydralazine is short acting, so even though you may have addressed the hypertensive emergency in the first few minutes with this intravenous medicine, you will need a plan for longer lasting maintenance of that blood pressure reduction - you can’t just sit there all day giving boluses of hydralazine…
Bonus: When do the first and second heart sounds occur?
Answer in tomorrow’s dose.
News: I made a little Ward Call Course for you all. It maps out an Evening Ward Call shift and covers a bunch of common tasks that you may need to do, like:
Deteriorating Patients
Heparin Infusions
Fluid Orders
Electrolyte Replacement
Difficult patients - Discharge Against Medical Advice, Ryan’s Rule
End of Life etc
You can find the course page here:
It’s free and always will be. Let me know what you think.
Remember, you are free to rip these questions and answers and use them for your own flashcards, study and question banks.
As always, please contact me with any questions, concerns, tips or suggestions. Have a great day!
Luke.