IPC in healthcare construction/renovation: review of ASHE matrix

This document summarises the Infection Control Risk Assessment (ICRA) published by American Society for Health Care Engineering (ASHE) which is a part of Pre-Construction Risk Assessment (PCRA), the essential tool we use to protect Environment of Care (EOC). In healthcare environment, construction is not just a facility update, it is rather a clinical intervention. Infection Prevention and Control (IPC) team member needs to evaluate construction or renovation project in hospital for environmental risks which can affect patient safety.

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What is ICRA and why it matters?

ICRA is a specialized tool used to stratify and identify the infection control risks associated with any construction or renovation project. It is governed by a multi-step matrix that categorizes activities by their potential to generate dust and debris and matches them against the vulnerability of the patient populations in the affected areas. Why is this process mandatory? The answer is that Environmental disturbances—including above-ceiling work, structural repairs, or running cables—markedly increase Aspergillus spore counts in the indoor air. While harmless to the healthy, these spores significantly increase the risk of healthcare-associated Aspergillosis in high-risk patients. Because these cases are often difficult to link to a specific exposure, the ICRA provides a proactive standard to identify and correct environmental risks before they impact our patients.

Once the clinical risks are understood, the step-1 in the ICRA process is to categorize the work itself.

Step-1) Categorizing the Construction Activity Type:

The first stage of the ICRA is defining the scope of work. While the project is divided into 4 types (A through D), we classify them based on the scale and nature of the physical activity.

After defining the intensity of the work, the step-2 in the ICRA process is to identify the specific patient populations in the immediate vicinity.

Step-2) Identifying Affected Patient Risk Groups:

In a hospital, risk is determined by patient susceptibility. We categorize areas into 4 groups (Low risk through Highest risk) to ensure that our most vulnerable populations receive the highest level of protection. If multiple groups are affected, the higher risk group must be selected.

• Low Risk: Non-patient care areas (e.g., public hallways, office areas, breakrooms, mechanical rooms, or bathrooms not located on clinical units).
• Medium Risk: Patient care support areas (e.g., waiting areas, clinical engineering, materials management, sterile processing deapartment – dirty side, and food services/cafeterias).
• High Risk: Direct patient care areas {e.g., all acute care units, emergency rooms (ER), employee health, pharmacy- general work zones, medication/clean utility rooms, laboratory, and imaging suites – diagnostic imaging}.
• Highest Risk: Highly compromised or sterile environments {e.g., intensive care units (ICU), oncology, operating rooms (OR), transplant unit, oncology unit, procedural suites, pharmacy – compounding, sterile processing deapartment – clean side, transfusion services, isolation wards, and imaging suites – invasive imaging}

Next is step-3 in the ICRA process to identify Class of Precautions of the ICRA which is obtained when these work types and risk groups meet.

Step-3) Navigating the ICRA Matrix:

The ICRA Matrix is the logical engine of the assessment. By matching the Patient Risk Group with the Construction Activity Type, we determine the Class of Precautions.

Reading the Matrix: We need to find our Risk Group in the left-hand column and follow the row to the right until weintersect with the Column of our Work Type. The resulting Roman numeral is our required safety standard.

ICRA Matrix:

Note:

• Formal approval (Infection control permit) is required for Class III (Type C) and all Class IV or V activities.
• Type C (Medium Risk) and Type D (Low Risk) work areas (Class III*) that cannot be sealed and isolated from occupied patient care spaces should be elevated to Class IV negative air exhaust requirements.
• Situations involving sewage, mold, asbestos, or gray/black water automatically require Class IV (for Low/Medium Risk) or Class V (for High/Highest Risk).

Once the Matrix identifies the Class, the step-4 in the ICRA process is to implement specific actions to maintain the EOC.

Step-4) Implementing the Class of Precautions:

Impacted surrounding areas (above, below, lateral, front, and behind) must be identified. Mitigation strategies are applied to noise, vibration, ventilation {e.g. HEPA exhaust to the exterior (at least 25 feet from intakes)}, and other critical systems (e.g. data, mechanical, medical gases, or water).

Each Class represents a tiered level of containment and air management. The following protocols must be followed based on the assigned Class of Precautions.

Class I

• Perform work activity in a manner that does not create dust.
• Avoid interrupting patient care
• Replace any displaced ceiling tiles before leaving the area and/or at end of work activity.

Class II

• Limited to basic facilities work with minimal dust
• Following standing precautions approved by the organization.
• Class II is never to be used for full construction or renovation.

Class III

• Barriers: Provide active means to prevent airborne dust (e.g. hand-held HEPA vacuums, poly containment, or closing doors). Seal doors with non-residue tape
• HVAC Isolation: Isolate HVAC (supply and return) to avoid dust entry.
• Air Pressure: Maintain neutral to negative pressure.
• Debris Transport & Cleanup: All trash and debris must be completely contained within the work area. Debris must be moved out in hard-lidded, damp-wiped containers.

Class IV

• Critical Barriers: Use more rigid barriers (such as hard-wall assemblies) to the deck above; seal all penetrations (holes, pipe conduits, and punctures); basic plastic sheeting is typically inadequate.
• Negative Air Pressure: Maintain continuous negative airflow cascading from the entry point to the construction area; use HEPA exhaust (if exhausted indoors). Install external devices to continually monitor negative pressure, preferably with visual indicators.
• Personnel Hygiene: Workers must wear shoe covers (changed when exiting to non-work areas); ensure clothing is HEPA vacuumed or use cover suits.

Class V

• Anteroom: A mandatory anteroom must be constructed for staging, cleaning, and worker transitions.
• PPE: Personnel must wear disposable cover-alls at all times, removed only within the anteroom before exiting.
• Containment: Includes all Class IV requirements, such as critical barriers, negative air monitoring, and sealed waste transport.

Completion:

Work is not considered complete until the environment is restored and inspected.

Cleaning and HVAC Restoration:

• Cleaning: All surfaces, high horizontal areas, and flooring must be cleaned.
• HVAC: Remove isolation, verify systems are clean, and ensure airflow/exchange meets original design specifications.

Inspection and Barrier Removal (Classes III-V):

For Class III (Type C), IV, and V, an Engineering representativ along with IPC team member should inspect the area before downgrading precautions.

• Barrier Removal Protocol: Barriers must remain until cleaning is finished. During removal, screws and tape must be removed carefully; drywall cutting is strictly prohibited. Stud tracks must be HEPA vacuumed before the outer barrier is removed.
• Negative Air: Devices must remain operational after dust-creating activities end to ensure contaminants are removed before barriers are taken down.

Conclusion: For any construction/renovation in hospital to succeed safely, the IPC is an important component of the project. Construction in healthcare is not just a building project; it is a commitment to the safety of the patients and staff.

_{Citation: American Society for Health Care Engineering. (2022). ICRA 2.0: Matrix of Precautions for Construction, Renovation and Operations. American Hospital Association.}