Question 15.2

Last updated 08/07/2017 - 18:45
 Topic: Infectious Disease Antibiotics and Sepsis
Pass rate
80%
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Other SAQs in this paper:

This is the second part of a multi-part SAQ. The first part was as follows:

You are called to review a 48-year-old male in the post-operative recovery unit (PACIJ) who has just undergone resection of a TSH-secreting pituitary adenoma via a trans-sphenoidal approach. He is febrile (38.5'C) and is hypertensive (160/50 mmHg) with tachycardia (130 beats/min) and hyper-dynamic circulation, and is hyper-reflexic.

Give the likely diagnosis.        (10% marks)

List your immediate pharmacological management.            (30% marks)

The patient subsequently recovered and was discharged home. He re-presented two weeks later with increasing drowsiness, confusion, fevers, neck stiffness and a clear nasal discharge.

Give the likely diagnosis.        (10% marks)

Briefly outline your immediate management.          (30% marks)

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College answer

c) CSF leak post-surgery with meningitis

d)

  • Intubation for airway protection if indicated and ventilatory support
  • Haemodynamic resuscitation / support as indicated
  • Blood cultures LP (post CT scan)
  • Broad-spectrum antibiotics with CNS penetration (e.g. meropenem and vancomycin)
  • Referral to neurosurgery / ENT (ID input)

Discussion

The previous question using this stem had the patient develop a thyroid storm following the resection of a TSH-secreting adenoma, a rare complication. The complication in the SAQ is more common. 

This is basal meningitis due to a dural breach. The breach has allowed filthy nose organisms into the brain, and now they swarm though the meninges. 

Management of this:

  • Obviously, ABCs
  • Confirm CSF leak by testing the clear discharge for β-transferrin
  • Lumbar CSF drain - to decrease the volume of CSF leak and to allow the CSF fistula to heal
  • Antibiotics (see below)
  • Instructions to avoid blowing one's nose 
  • If the lumbar drainage fails to control the leak, a surgical repair of the defect may be attempted (eg. by using some sort of patch).

As far as choice of antibiotics goes, it is unclear wherther one should treat this as a meningitis following base of skull fracture (which it pathophysiologically resembles) or post-surgical meningitis (which it ontologically is).  In the former, S.pneumoniae and H.influenzae are the dominant organisms, whereas in post-operative cases the bug is either S.aureus or S.epidermides. In either case, vacomycin and ceftriaxone are recommended by the Sanford Guide. In both cases, dexamethasone (0.15mg/kg) is recommended. 

References

Ciric, Ivan, et al. "Complications of transsphenoidal surgery: results of a national survey, review of the literature, and personal experience."Neurosurgery 40.2 (1997): 225-237.

Van Aken, M. O., et al. "Cerebrospinal fluid leakage during transsphenoidal surgery: postoperative external lumbar drainage reduces the risk for meningitis." Pituitary 7.2 (2004): 89-93.

Nishioka, H., J. Haraoka, and Y. Ikeda. "Risk factors of cerebrospinal fluid rhinorrhea following transsphenoidal surgery." Acta neurochirurgica 147.11 (2005): 1163-1166.

Black, Peter McL, Nicholas T. Zervas, and Guillermo L. Candia. "Incidence and management of complications of transsphenoidal operation for pituitary adenomas." Neurosurgery 20.6 (1987): 920-924.

Mathias, Tiffany, et al. "Contemporary approach to the diagnosis and management of cerebrospinal fluid rhinorrhea." The Ochsner Journal 16.2 (2016): 136-142.

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