Pituitary infarction: a potentially fatal cause of postoperative hyponatraemia and ocular palsyBMJ 2011; 342 doi: https://doi.org/10.1136/bmj.d1221 (Published 17 March 2011) Cite this as: BMJ 2011;342:d1221
- Helen Prescott, medical student1,
- Elna Ellis, registrar, endocrinology2,
- Steven Soule, consultant endocrinologist2
- 1Medical School, University of Sheffield, Sheffield S10 2RX, UK
- 2Christchurch Hospital, Christchurch, New Zealand
- Correspondence to: H Prescott
- Accepted 16 November 2010
Hyponatraemia is the most common electrolyte disturbance in hospital inpatients. Accurate assessment of the cause and appropriate treatment are crucial.1 Hyponatraemia after orthopaedic surgery is often caused by hypotonic fluids and factors that increase secretion of antidiuretic hormone, and it resolves with fluid restriction.2 3 But this is not always the case, and other causes should be considered. We describe a patient with haemorrhagic infarction of a pituitary adenoma and symptoms of blurred vision from oculoparesis who presented shortly after hip replacement, in whom hyponatraemia was caused by cortisol deficiency.
A 58 year old man presented with a drooping right eyelid and diplopia nine days after a right total hip replacement. He had previously been fit and well requiring no regular drugs other than analgesia.
Surgery was performed under spinal anaesthesia. Blood pressure before surgery was 139/91 mm Hg. Within 30 minutes of anaesthetic induction his systolic blood pressure dropped to 90 mm Hg and was about 70 mm Hg for most of the procedure. He received 3 L of crystalloid in theatre and his blood pressure was 90/60 mm Hg at the end of surgery, rising to 152/95 mm Hg two hours later. He received prophylactic aspirin (150 mg daily) but no low molecular weight heparin.
About 10 hours after surgery he developed a severe headache, nausea, and vomiting. He was treated symptomatically and three days later the symptoms had largely resolved. On the day of discharge (postoperative day 6), his wife noticed drooping of his right eyelid and the patient mentioned that his vision had been blurred since surgery. A doctor was consulted by telephone and advised that no action was needed.
The patient presented to his general practitioner nine days …