The following results are from a 29-year-old post-partum female, day 6 following elective Caesarean section at 37 weeks gestation for placenta accreta, complicated by massive intra-operative haemorrhage.

She made a good recovery but has had a persisting dull headache, dizziness, lethargy, polyuria and failure of lactation.

Parameter

Patient Value

Normal Adult Range

Sodium

114 mmol/L*

135 - 145

Potassium

4.6 mmol/L

3.5 - 5.0

Bicarbonate

26 mmol/L

22 - 32

Urea

2.2 mmol/L*

3.0 - 8.0

Creatinine

46 mmol/L

45 - 90

Serum osmolalitv

232 mOsm/L*

275 - 295

Urine osmolality

493 mOsm/L

a) Give the diagnosis for this clinical picture. (20% marks)

b) How will you confirm the diagnosis? (20% marks)

c) Outline the underlying pathophysiology of this condition. (20% marks)

d) What is your immediate treatment? (10% marks)

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College answer

a)    Sheehan's syndrome.                                         
 
b)    MRI brain showing empty pituitary fossa                      
Hormone profile – cortisol, TFTs, prolactin 
 
c)    Ischaemic pituitary necrosis due to severe post-partum haemorrhage. Vasospasm, thrombosis and vascular compression of hypophyseal arteries with an enlarged pituitary gland and DIC are possible factors. 
 
d)    Hydrocortisone.  
 

Discussion

a) This is a hypoosmolar hyponatremia with history of polyuria, failure of lactation, and lethargy. All sounds very endocrine. Given the history of pospartum haemorrhage, one must consider post-partum hypopituitarism, or Sheehan' syndrome.

b) Endocrine-sounding tests are in order.

  • Prolactin level
  • TFTs
  • Random cortisol (or short synacthen test)
  • MRI of the sella turcica

c) The pituitary gland in pregnancy is enlarged, and in context of haemorrhagic shock it can become infarcted. As a result of this:

  • Vasopression stores are depleted, resulting in initial polyuria
  • ACTH secretion decreases, resulting in hypoadrenalism, with lethargy and hyponatremia
  • TSH secretion decreases, also resulting in lethargy and hyponatremia
  • Prolactin secretion cannot increase, resulting in failed lactation

d) Supplement the following:

  • Cortisol (as hydrocortisone)
  • Thyroid hormone (as oral thyroxine)

References

References

Cukierman, Ronit L., et al. "Post-Partum Hyponatraemia in the Setting of Massive Haemorrhage: An Unusual Presentation of Sheehan? s Syndrome." Critical Care Obstetrics and Gynecology (2016).