From Exam Rooms to Hybrid ORs

In healthcare facility design, the distinctions between room types are necessary for ensuring patient safety, compliance with regulations, and optimized operations. While the terminology might seem straightforward, understanding the specific functions and requirements of exam rooms, procedure rooms, operating rooms (ORs), and imaging rooms can make a world of difference for architects, healthcare planners, and operators. The following generally references The FGI Guidelines for Design and Construction of Outpatient Facilities and ASHRAE 170 standards.

Exam Rooms: The Foundation of Care

Exam rooms are the least restrictive of the three types. These rooms are accessed from unrestricted areas and serve as the primary space for patient consultations, routine check-ups, and noninvasive procedures. They are designed for straightforward tasks and basic monitoring.

Key Features:

• Size and Layout: Typically 80–120 square feet, depending on use.
• Environment: No sterile field or specific air pressure requirements. 4 air changes per hour (ACH), a maximum of 60% relative humidity (RH), a temperature of 70-75F, and MERV-8 filtration are recommended.
• Examples of Use: Patient examinations, blood draws, minor dermatological procedures, and basic diagnostic tests.

Procedure Rooms: The Middle Ground

Procedure rooms provide a semi-restricted environment for more complex tasks that don’t meet the definition of "invasive" surgery. These rooms are equipped for minimally invasive procedures like simple biopsies, injections, minor orthopedic procedures, and vascular access procedures, typically using local anesthesia or minimal to moderate sedation. Deep sedation or general anesthesia are not prohibited, but are dependent on the Governing Body's determination that they are appropriate and safe for this setting.

Key Features:

• Size and Layout: Minimum of 130 square feet, or 160 square feet with anesthesia cart. Larger rooms are often required to accommodate the needs of the specific procedures. Preparing room layouts with equipment and personnel to test the size during design is always a good idea.
• Environment: Generally requires high-level disinfection and some environmental controls but is not required to have the environmental controls of an operating room. Positive air pressure, 15 total ACH, 3 outdoor ACH, 20-60% RH, 70-75F, and MERV-14 filtration are required by ASHRAE 170.
• Examples of Use: Urological procedures, wound debridement, laser procedures, skin biopsies, catheterizations, certain ENT procedures, and interventional pain management.

Procedure rooms strike a balance by supporting sterility while not requiring the stringent conditions of an OR. They may or may not require emergency power depending on their use and the risks associated with the procedures done within them. 

Endoscopy Procedure Rooms: Diagnostic Interventions

Endoscopy procedure rooms are designed for minimally invasive procedures where flexible scopes are inserted through natural body orifices to examine internal organs. While many of the procedures are diagnostic in nature, they also involve minor surgical procedures, such as polyp removal, typically performed through the endoscope.

Key Features:

• Size and Layout: Endoscopy rooms should be a minimum of 180 square feet. Larger rooms are sometimes required to accommodate the needs of specific procedures.
• Environment: 6 total ACH, 2 outdoor ACH, maximum 60% RH, 67-73F, and MERV-8 filtration are required by ASHRAE 170. There is no room pressurization requirement.
• Examples of Use: Colonoscopies, endoscopy, endoscopic ultrasound, ERCP, capsule endoscopy, and ablation.

Endoscopy procedure rooms are specific to the use. Depending on the risks and levels of sedation used, they may required emergency power. As endoscopy procedures evolve, room requirements will also evolve. For instance, C-arms are now being used for certain GI procedures and this indicates the potential need for a shielding analysis in the planning phase.

Operating Rooms: The Workhorse of Surgical Care

Operating rooms are some of the most controlled and complex environments in outpatient healthcare facilities. Designed for invasive procedures that expose sterile body cavities or involve high infection risks, ORs require meticulous planning and infrastructure. Procedures that require physiological monitoring and active life support should be performed in an OR. They are restricted areas that must be entered through semi-restricted areas.

Key Features:

• Size and Layout: Minimum 255 square feet without anesthesia equipment, or 270 square feet with anesthesia equipment. OR's for more complex procedures involving more personnel and equipment may be 400 square feet or greater.
• Environment: To maintain a sterile field, includes unidirectional airflow with a laminar flow array at the ceiling and low returns in opposite corners. Positive pressure, 20 ACH, 4 outdoor ACH, 20-60% RH, 68-75F, and MERV-16 filtration. OR's for orthopedic procedures, transplants, and neurosurgery now require HEPA filters in the air terminal device.
• Examples of Use: Total joint replacements, arthroscopy, spine and neurosurgery, ophthalmic surgery, ENT, urological and gynecological surgery, and plastic surgery.

ORs require the strictest sterility and infection control measures. They typically have monolithic, scrubbable surfaces, specialized lighting, emergency power, and an infrastructure that supports anesthesia as well as advanced surgical equipment.

Class 1, 2, and 3 Imaging Rooms

The evolution of imaging technologies has blurred the lines between diagnostic, interventional, and surgical procedures, leading to a classification system for imaging rooms. These classifications—Class 1, 2, and 3—reflect the level of patient acuity, procedural invasiveness, and environmental control needed.

Class 1 Imaging Rooms: Diagnostic Only

• Designed for basic, non-invasive, diagnostic imaging, such as x-rays, mammography, CT, ultrasound, MRI, and other types of imaging.
• Environmental controls are similar to exam/treatment rooms, except 6 ACH is required rather than 4.

Class 2 Imaging Rooms: Diagnostic and Therapeutic

• These rooms support minimally invasive procedures that require image guidance during intervention, such as catheterizations, interventional angiography, or electrophysiology studies.
• Environmental controls are similar to a procedure room. Class 2 Imaging Rooms are semi-restricted areas and may be entered through unrestricted or semi-restricted areas.

Hybrid ORs (Class 3 Imaging Rooms) - The Future of Surgery

Hybrid operating rooms are flexible spaces that blend the functionality of a traditional OR with advanced imaging capabilities. These rooms support invasive procedures requiring real-time imaging where patients will require physiological monitoring and life support.

Key Features:

• Size and Layout: Minimum 600 square feet, but must be sized for the specific equipment and operational clearances required within the room. Hybrid ORs also require a control room with a view window into the OR and a dedicated equipment room.
• Environment: Requires the environmental standards of an Operating Room.
• Examples of Use: Cardiovascular, endovascular, and neurosurgical procedures where precise image guidance is necessary. May involve both open and minimally invasive surgery.

Due to the fixed imaging equipment in the room, Hybrid ORs require radiation shielding and have unique structural requirements. These rooms enable precise interventions, reduce the need for multiple procedures, and improve patient outcomes. 

Why These Differences Matter - Bridging Design and Functionality

Healthcare architects and engineers play a crucial role in translating clinical needs into compliant and functional spaces. By working closely with multidisciplinary teams, they ensure that room types align with the intended uses. Understanding the distinctions in room types impacts facility design in several ways, such as maintaining regulatory compliance, balancing construction and operating costs, and promoting operational efficiency and effectiveness. These differences aren't just technical—they directly influence patient outcomes and the quality of care.