Cutting Edge Image-Guided Surgery Demands Hi-Tech HVAC Engineering for Patient and Staff Safety

Patient Infection Prevention is Paramount in BWH World-Class Surgical Suite
by John McCarthy, Sc.D., C.I.H.

The challenge of ensuring patient infection protection in the most sophisticated image-guided surgical suite in the world demanded the unique expertise and guidance of EH&E’s healthcare engineering and environmental specialists. BWH’s AMIGO1 Suite is the first OR to provide interventional radiologists and surgeons with immediate access to a full array of advanced imaging modalities for use during multiple procedures. The 5,700 sf suite includes a central OR and two adjoining rooms and it houses real-time state of the art imaging modalities such as X-ray fluoroscopy and ultrasound, as well as cross sectional digital imaging systems like CT, high field strength MRI and high resolution PET.

Situational Diagnosis: Infection Control and Thermal Comfort Challenges

Working with the surgical and design teams, the key engineering challenges that EH&E identified and addressed included:

  • Installation of the ceiling-mounted supports for suspending the 28,000-pound MRI scanner over the patient negated the conventional placement of the air supply vents directly over the surgical table. As surgical site infections are largely sourced to skin cells that are shed from the arms, necks, and heads of surgical staff, maintaining effective air flow control over the surgical site is critical to minimize this transfer.
  • Increased heat loads over traditional OR designs were determined to exist and potentially tax existing systems due to both additional equipment cooling loads and increased personnel present in the suite to operate the new equipment.

Treatment: Engineering Analysis and Proposed Suite Configuration

Using advanced computational fluid dynamic (CFD) modeling, our scientists and engineers evaluated multiple HVAC configurations and airflow patterns for critical infection control and optimal thermal comfort. The results identified that careful placement of a diffuser array in a non-traditional configuration would be equally effective in preventing particles (skin cells) from impacting the surgical site when compared to conventional systems.

This approach not only was subject to peer review by BWH surgical and mechanical design teams, it also had to pass regulatory approval from the Massachusetts Department of Public Health for licensing of the AMIGO suite. BWH had to prove that the proposed non-traditional ventilation design for the AMIGO Suite would meet the ASHRAE requirements for ventilation (ASHRAE Standard 170-2008 – Ventilation of Health Care Facilities).

Outcome: Successful Licensure and Opening of AMIGO Suite at BWH

On May 4, 2011, BWH unveiled the new AMIGO suite for patient care, ushering in a new approach for fostering innovation in integrated surgical care with newly available radiological modalities in the OR. We are proud to have played a part in the design of the AMIGO suite and securing of the licensure for this non-traditional suite through the Department of Public Health.

Additional information on the BWH AMIGO Suite is available from BWH.

  1. Advanced Multimodality Image Guided Operating (AMIGO Suite)