Awake craniotomy paired with intraoperative magnetic resonance imaging (iMRI) is now the established technique for maximizing surgical resection, while preserving neurological function. However, leaving an unsecured airway patient in the iMRI gantry represents considerable risk. Our study aimed at identifying the incidence of critical adverse events in unsecured airway patients during iMRI as part of awake craniotomy.
Materials and Methods:
We conducted a clinical chart review of consecutive awake craniotomies performed between November 1999 and December 2015. Sequences of iMRI performed without invasive airway management were selected for assessment and the incidence of critical adverse events, including general convulsive seizure, respiratory arrest, nausea/vomiting and agitation, was identified.
Critical adverse events occurred in 21 of 356 unsecured airway patients within 24 of the 579 iMRI sequences. In cases using the low-field strength open MRI scanner, emergency termination of scans due to patient decline was recorded in only 4 cases: no cases of cardiac arrest, accidental death, or thermal injury were recorded. Compared with cardiovascular monitoring, patient respiratory status was poorly recorded.
In terms of anesthesia, concurrent use of iMRI for awake craniotomy is clinically acceptable providing potential intraoperative complications can be controlled. Further, the configuration of the iMRI scanner as well as the reduced exposure from the lower magnetic field strength was found to impact patient safety management. Therefore when a conscious patient is left in the gantry without airway support, it is advisable that levels of oxygenation and ventilation should be monitored at all times.