Advanced, Special Problems or Issues in Anesthesiology
- Zone I: This region includes all areas that are freely accessible to the general public.
- Zone II: This area is the interface between the publicly accessible uncontrolled zone I and the strictly controlled zone III
- Zone III: Only screened MRI patients and personnel have control to this restrictive zone. In this zone, there are potentially hazardous energies (related to the MR imaging process) present.
- Zone IV: The zone always located within Zone III. The zone houses the MRI scanner. In this zone, MRI patients under constant, direct supervision of trained MR personnel.
Patient care can be provided in all zones; however, the strong magnetic field in zone IV restricts resuscitation efforts as certain medical devices (i.e. defibrillators) cannot be used safely in Zone IV. The ASA updated their Practice Advisory on Anesthetic Care for Magnetic Resonance Imaging in 2014. As noted in the advisory:
When a patient has a medical emergency (e.g., cardiopulmonary arrest) in the MRI scanner, the following should occur:
- Immediately remove the patient from zone IV while initiating CPR, if indicated
- Call for help
- Transport the patient to a previously designated safe area for resuscitation that is not in zone IV. This location should be as close to zone IV as possible so as not to delay resuscitation efforts and should contain the following resuscitation equipment: a defibrillator, vital signs monitors, and a code cart that includes resuscitation drugs, airway equipment, oxygen, and suction.