Subarachnoid Haemorrhage Craniotomy with Anaphylaxis

You are called to the neurosurgical theatre by your provisional fellow who requests your assistance. They have anaesthetised a 36-year-old woman for a craniotomy and open clipping of a saccular middle cerebral artery aneurysm. The patient was admitted with a sudden onset of headache two days prior and was diagnosed with a World Federation of Neurosurgical Societies (WFNS) grade I subarachnoid haemorrhage. Medical History Hypertension Asthma Medications Nimodipine 60 mg four-hourly Irbesartan 150 mg daily Salmeterol/Fluticasone 250/25 mcg via metered-dose inhaler (MDI) daily Salbutamol 100 mcg via metered-dose inhaler (MDI) PRN Allergies Morphine (rash) When you attend the theatre, you discover that the patient was induced, intubated and anaesthetised uneventfully. She is currently being maintained on total intravenous anaesthesia, with target-controlled infusions of remifentanil and propofol. The patient has an arterial line and a central venous catheter in situ. Surgery is underway. The provisional fellow is concerned that the patient has developed high airway pressures and a heart rate of 120 beats per minute.