Between Issues

When the Fluoroscopy C-arm Collides with the Anesthesia Machine

January 15, 2021

Alina Razak (Medical Student); Molly Vora (Medical Student); Mauricio Gonzalez, MD (Clinical Associate Professor); Rafael Ortega, MD (Professor)

Patient Monitor

Recently, a patient was undergoing a procedure with general anesthesia and mechanical ventilation in the electrophysiology laboratory. Towards the end of the case, the floor-mounted C-arm was accidentally throttled forward by a trainee using the controller. The C-arm rapidly displaced and collided with the anesthesia machine. The carbon dioxide absorber and the Compact Breathing System of a Dräger Fabius anesthesia machine broke off the mount and fell to the floor (Figure 1). The machine was disabled, halting mechanical ventilation and delivery of inhaled anesthetics. The anesthesia professional continued delivering positive pressure ventilation using a bag valve device. General anesthesia proceeded with the use of intravenous anesthetic agents.

Figure 1: Compact Breathing System of a Dräger Fabius machine broken off its mount.

Figure 1: Compact Breathing System of a Dräger Fabius machine broken off its mount.

While there were no adverse consequences, this incident had the potential to harm the patient and the staff. The case highlights the importance of not only being prepared for an anesthesia delivery apparatus malfunction, but also being vigilant in preventing equipment compromise. The American Society of Anesthesiologists ​Statement on Non-Operating Room Anesthetizing Locations advises that anesthesia personnel should have access to “a self-inflating hand resuscitator bag […] to deliver positive pressure ventilation, adequate anesthesia drugs […], and adequate monitoring equipment”.1

Incidents involving C-arm collisions have been reported2 and their prevention is imperative. A C-arm is capable of generating a destructive force. It can produce a momentum of over 380 Newton-second,3,4 which is equivalent to that of a Harley-Davidson motorcycle traveling at approximately 3 miles per hour.5

Unintended movement of the C-arm leading to subsequent damage is uncommon. However, it is important to always take proper precautions. Ensuring that all C-arm operators have adequate training prior to maneuvering the equipment is crucial. All personnel in the room must be aware of how the C-arm will be used by discussing it during the pre-procedure checklist, particularly when reviewing special equipment needed for the case.6 Additionally, guidelines on minimum distance between the C-arm, personnel, and other equipment should be established so there is sufficient space to minimize the possibility of a collision.

Technological advancements could include sensors that detect patients or other objects and are capable of decelerating or halting the C-arm if there is insufficient distance for further movement.7 There is interest in developing and implementing such sensors by using three-dimensional depth measurement techniques8 and simulating virtual environments of the procedure room.9

This case illustrates the importance of the availability of both medical and collision prevention back-up equipment. Clinicians should take appropriate precautions to avoid similar incidents.


Alina Razak (Medical Student)
Department of Anesthesiology
Boston University School of Medicine

Molly Vora (Medical Student)
Department of Anesthesiology
Boston University School of Medicine

Mauricio Gonzalez, MD (Clinical Associate Professor)
Department of Anesthesiology
Boston University School of Medicine

Rafael Ortega, MD (Professor)
Department of Anesthesiology
Boston University School of Medicine

None of the authors have any conflicts of interest.


  1. American Society of Anesthesiologists Committee on Standards and Practice Parameters. Statement on Nonoperating Room Anesthetizing Locations. 2018. Accessed August 27, 2020.
  2. Mullins, A. Inadvertent C-arm Movements: Potential Cause of Patient and Staff Injury. J Vasc Interv Radiol. 2008;19:167-168. DOI: 10.1016/j.jvir.2007.09.025.
  3. GE Healthcare. OEC 9900 Elite Premium C-arm Technical Data. 2017. -Technical-Data-Sheet.pdf. Accessed August 27, 2020.
  4. Renate L, Postolka B, Schutz P, et al. A moving fluoroscope to capture tibiofemoral kinematics during complete cycles of free level and downhill walking as well as stair descent. PLoS ONE. 2017;12. DOI: 10.1371/journal.pone.0185952.
  5. Harley-Davidson. Cruiser – 2020 Low Rider S. 2020. Accessed September 14, 2020.
  6. The Joint Commission. The Universal Protocol. 2020. Accessed August 27, 2020.
  7. Spahn, M. Medical imaging system and anti-collision method with a controllable arm. 2006. Google Patents. Accessed August 27, 2020.
  8. Khan, MS. Collision Avoidance for Predefined C-arm Trajectory using 3D Depth Measurements. Delft University of Technology Master Thesis. 2016. Accessed August 27, 2020.
  9. Ladikos A, Benhimane S, Navab, N. Real-time 3D Reconstruction for Collision Avoidance in Interventional Environments. Med Image Comput Comput Assist Interv. 2008;11(Pt 2):526-534. DOI: 10.1007/978-3-540-85990-1_63.