Your Daily Meds - 8 December, 2021 Your Daily Meds

Good morning and welcome to your Wednesday dose of Your Daily Meds.
Bonus Review: Why is it that the posterior pituitary has neural connections with the hypothalamus, but the anterior pituitary has vascular connections with the hypothalamus?
Answer: Well the posterior pituitary is part of the brain, so develops with the expected neural connections. The anterior pituitary develops from Rathke’s Pouch, an ectodermal outpouching from the roof of the oral cavity, and so develops vascular connections with the hypothalamus.
Some Obstetrics:
Which of the following is least likely to be responsible for uterine atony after birth?
* Chorioamnionitis 
* Prolonged labour
* High parity
* Multiple pregnancy
* Oligohydramnios
Have a think.
Scroll for the chat.
Case:
A 61-year-old male is seen on the wards 2-days after abdominal aortic aneurysm repair. He was noted to have an increase in serum creatinine by 55 µmol/L over the two days since surgery, and has been passing urine at a rate of 0.4 mL/kg/h for the last 8 hours up until the time of review. Which of the following investigation results is most strongly supportive of a diagnosis of prerenal acute kidney injury?
* Serum Urea : Serum Creatinine ratio of 5:1
* Serum Urea : Serum Creatinine ratio of 1:20
* Serum Urea : Serum Creatinine ratio of 1:30
* Serum Urea : Serum Creatinine ratio of 30:1
* Serum Urea : Serum Creatinine ratio of 10:1
Have a think.
More scroll for more chat.
“I Don’t Like Your Tone”:
Uterine atony is the most common cause of postpartum haemorrhage due to failure of the contracting uterus to occlude the vessels supplying the placental bed. 
Uterine atony is less common with ‘active management’ of the third stage of labour, that stage between delivery of the baby and delivery of the placenta. The administration of oxytocic drugs and assisted delivery of the placenta halves the risk of postpartum haemorrhage due to uterine atony compared to those women choosing a ‘natural’ third stage of labour. 
Other causes of impaired uterine retraction after birth include chorioamnionitis, uterine ‘exhaustion’ after prolonged labour, high parity, and overdistension of the uterus during pregnancy. Overdistension of the uterus may be caused by a large baby, multiple pregnancy or polyhydramnios.
From the list, oligohydramnios is least likely to be responsible for uterine atony after birth.
Those (A)KIdneys:
Acute kidney injury (AKI) is defined as an abrupt (within 48 hours) decline in kidney function, as manifested by any of:
* Absolute increase in serum creatinine by 26.4 µmol/L or greater
* An increase in serum creatinine from baseline by 50% or greater
* Reduction in urine output, defined as less than 0.5 ml/kg/h for more than 6 hours.
AKI is commonly classified as prerenal, intrarenal or posterenal as a descriptor of aetiology and differential diagnoses. 
The ratio of Serum Urea : Serum Creatinine is an important finding and, when exceeds 20:1, suggests conditions of increased reabsorption of urea as in a prerenal AKI.
Bonus: With respect to the physiology of muscle contraction, what is a motor unit?
Answer in tomorrow’s dose.
Closing:
Thank you for taking your Meds and we will see you tomorrow for your MANE dose. As always, please contact us with any questions, concerns, tips or suggestions. Have a great day!
Luke.
Remember, you are free to rip these questions and answers and use them for your own flashcards, study and question banks.
Just credit us where credit is due.


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