ANZCA EXAM Q 1996A06--neuroanesthesia
1996A06: A previously well 38 yo man presents for urgent clipping of a middle cerebral artery aneurysm.He has photophobia, and a blood pressure of 150/90Outline how you would manage post-operative vasospasm in this patient
General Measures
• Ensure adequate patent airway and avoid hypoxaemia
• Monitor in intensive care unit.
o CVP
o invasive arterial pressure recording
o Regular monitoring of neurological state is essential.
Specific Measures to increase perfusion:
• Triple H therapy – mainstay of mx since 1970s – prospectively shown to reduce morbidity and mortality from vasospasm ~20% (1980s) to 5-10% although RCT data not available.
o Hypervolaemia:
Volume load with colloid (eg 5% Albumin or Gelofusine)
NS may be used (glucose and low sodium containing solutions are avoided)
Problems with pulmonary oedema, worsening cerebraloedema, myocardial ischaemia, haemorrhagic infaction
Only one prospective study supports use
Outcomes with hypervolaemia vs. normovolaemia compared in 1999 with RCT – no difference in global cerebral blood flow
Many patients with SAH present hypovolaemic – it is felt that this is more important to prevent
CVP aim usually 8-10 cmH2O
o Haemodilution
Eg Hb < = 11 g/dL
o Hypertension
Prior to aneurysm clipping aim for SBP < 110 mmHg or within 20% of baseline
Post – clipping: usually 20-30% above baseline – eg 150-170 mHg
may require the use of inotropic support e.g. low dose adr, NA
• calcium channel blockade - nimodipine is the drug of choice ( 60mg 4/24 for 21 days). Fausidil HCl is an alternative.
o shown to reduce the incidence and severity of vasospasm.
o mechanism remains unclear; possible vasodilation by calcium channel block, or free radical scavenging.
o Should be given either as IV infusion with accompanying flushing solution through a central line, or can be given orally three times per day.
o Should be commenced early in the management.
o Nicardipine has failed to show benefit
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