Outline the risks specifically associated with Magnetic Resonance Imaging of critically ill patients (you do not have to outline risks associated with transport to and from the scanner).
General risks of MRI
Magnetic field induced movement of ferromagnetic objects
* Ferrous Projectiles accelerating into scanner causing trauma
* Movement of ferrous implants and prostheses
* Movement of metallic foreign bodies, such as foreign bodies in the eye
* Malfunction/failure of pacemaker/ IAD
Specific risks with the critically ill patient
* Cold environment and prolonged exposure time away from ICU due to length of time it takes to do an MRI
* Patient inaccessibility
* Monitoring and ventilation equipment is limited and needs to be MRI compatible, often sub-optimal
* Unable to take resuscitation equipment into “magnet zone”
* Infusions may be difficult to run – MRI compatible pumps that can be used in “magnet zone” are not widely available. Long tubing can be used.
* Gadolinium exacerbation of nephrogenic systemic fibrosis
Potential risk of hyperthermia in patients with disordered thermal regulation (ie all critically ill patients)
Potential for burns (ECG dots)
Even though the college exclude transportation considerations from their question, they are important because according to one risk/cost/benefit analysis, "transportation of patients from the ICU resulted in a large number of physiologic changes, each requiring changes in support". Of these physiologic changes, 68% were described as "serious" (eg. requiring more vasopressors or a higher FiO2).
Now, to MRI issues. This article contains a chapter ("MRI Transport") which covers this topic in brief. A substantial detailed exploration can be found in David Olive's article for Australasian Anaesthesia(2005)
Risks from the magnet
Risks from contrast
Risks from the isolated room
Risks from being critically ill
INDECK, MATTHEW, et al. "Risk, cost, and benefit of transporting ICU patients for special studies." Journal of Trauma-Injury, Infection, and Critical Care 28.7 (1988): 1020-1025.
Tobin, J. R., E. A. Spurrier, and R. C. Wetzel. "Anaesthesia for critically ill children during magnetic resonance imaging." British journal of anaesthesia69.5 (1992): 482-486.
Blakeman, Thomas C., and Richard D. Branson. "Inter-and Intra-hospital Transport of the Critically Ill." Respiratory care 58.6 (2013): 1008-1023.
ANZCA have an excellent college publication on this exact topic:
D.Olive, "Don't Get Sucked in: Anaesthesia for Magnetic Resonance Imaging" - Australasian Anaesthesia 2005, pp.85