How properly engineered ventilation keeps patients safe
Our knowledge of the COVID-19 virus and the engineering controls associated with mitigating its transmission have evolved considerably since the pandemic hit the US earlier this year. We now know that it is highly unlikely for COVID-19 to travel through a code-compliant, multi-zone, hospital HVAC system (return ductwork, central air handling unit coils, final filters, and terminal units). There are no known instances of COVID-19 transmission through this pathway as of this writing.
The use of 100 per cent exhaust (where there's no recirculation via central air handlers) is not justified, except for rooms where aerosol generating procedures are performed and in the Emergency Department, where there are significant numbers of people under investigation. The use of central air systems with MERV 14-16 filters or local HEPA filtration have replaced most of the recommendations for 100 per cent exhaust.
Maintaining a space with an exterior wall or roof, such as most patient rooms, at negative pressure, where more air is extracted from the room than is supplied to it, can lead to infiltration of outside air through the building envelope, which can lead to serious health problems, most notably mold growth in the envelope construction.
The widespread use of individual room negative pressure relationships isn't justified, except for patient and exam rooms equipped with anterooms. There is limited protection afforded to healthcare workers once the door to an infected patient’s room is opened, no matter how negative the pressure relationship. Increased exhaust requires an enhanced intake of outside air, which results in system capacity issues and higher operating costs. In many cases, failure to maintain pressure relationships and air balance can cause loss of temperature and humidity control.
The current ASHRAE Standard 170 guidelines on Ventilation of Health Care Facilities have served us well and there is little evidence that going beyond those requirements yields cost-justified improvements in COVID-19 viral transmission mitigation. There is probably no safer place in a US built environment than a code compliant, well-operated and maintained hospital.
We have learned that the “normal” hierarchy of controls needs to be inverted in the case of this pandemic. Instead of PPE being the least effective, we have found that it is the most effective means of mitigating transmission. Elimination and substitution are simply impractical if not functionally impossible. Since the virus is transmitted person-to-person, it is impractical to use engineering controls to interrupt that pathway. The single most effective strategy is source control.
We advocate for a layered approach. This includes:
⦁ Normal mode where Airborne Infectious Isolation Rooms (AIIRs) may be limited to patients receiving aerosol generating procedures
⦁ Small scale surge capacity mode where it may be necessary to create additional dedicated rooms or temporary patient observation rooms with HEPA filtration and and negative pressure
⦁ Large scale surge where an established dedicated ward or even a separate building with its own set of protocols may be needed.
An alternative strategy to installing a HEPA filter unit in the ceiling and routing ductwork in the ceiling cavity, is to provide a ventilated headboard like the CDC suggests . This can be built on site.
When patient numbers grow beyond small scale surge capacity, hospitals could consider these options:
⦁ Cohort and Convert units, wings or floors where all patients in “hot” zones are considered infected
⦁ Using anterooms/vestibules to segregate “hot” from “cold” zones
⦁ Rather than converting individual rooms one at a time, use HEPA machines to create pressure difference
⦁ Create one-way flow if possible, with PPE donning in one anteroom and removing in another. These should be large enough to accommodate two caregivers, working in a “buddy system” and there should be handwash available
⦁ If necessary, create positive pressure zones for staff respite inside the hot zone, using HEPA machines to establish pressure differences, and using anterooms or vestibules if practical
Kim Shinn, PE, LEED Fellow and BEMP is a principal at TLC Engineering Solutions. He can be reached at [email protected]
How healthcare can safeguard itself against cyberthreats
One of the most fundamental lessons from the COVID crisis is that health should always be a priority. In a similar fashion to the human body that frequently fights off viruses and foreign invaders that intend to cause it harm, the sector itself is now a prime target for another type of external threat: cyberattacks.
The figures speak for themselves: between December and January this year, hospitals in the UK were at 89% capacity, with 7,000 fewer available beds than there usually are. As the pandemic increased pressure on hospitals, clinics, and research facilities to create a treatment for patients globally, it has left the sector exposed to hackers who, like a virus, have been targeting it relentlessly and evolving their tactics.
From patient records being held ransom, to fake emails claiming to originate from the UN WHO, the NHS, or vaccine centres, through to attacks on the cold supply chain to find out the secret formula of the COVID vaccine, the healthcare industry is facing constant cyberattacks and struggling to cope. This threat is unlikely to go away anytime soon – and as such, the industry needs to take a proactive, preventative stance to stay safe in a dynamic digital world.
The responsive nature of healthcare – particularly of hospitals – means that efficiency is crucial to the industry’s standard operations. To support this, the sector has been embracing technological advancements that can improve the quality of work, enabling staff to meet pressing deadlines, and enhancing patient care. For example, the industry has been digitising records and improving its ways of working through digital means over the past few years.
This shift is critical to offer high quality patient care; yet, it also means the sector has become more dependent on IT, which can come with a risk if cybersecurity processes employed are deemed as inadequate.
Without the correct security measures in place, the desired efficiency gains realised, can be easily lost in a heartbeat. Simply put, an elementary glitch in the system can have a tremendous ripple effect on many areas, from accessing patient records and conducting scans, to maintaining physical security and protecting the intellectual property of experimental treatment development.
To prevent this, healthcare organisations need to ensure they’re considering cybersecurity as part of their overall digital transformation strategy – and setting the right foundations to create a culture where safety goes hand in hand with patient care.
Before implementing cybersecurity process, healthcare organisations need to assess the potential risks they face. Depending on how much confidential data the trust has, where it is stored, who has access to it and via which means, the cybersecurity strategy and associated solutions will change.
It’s fair to say that a medical device start-up where all employees have a corporate-sanctioned laptop and access data via a VPN will have radically different needs to a large hospital with hundreds of frontline workers connecting to the hospital’s Wi-Fi using their personal device.
These requirements will pale by comparison to a global pharmaceutical giant with offices in multiple locations, a large R&D department researching new treatments for complex diseases and a fully integrated supply chain. Considering the existing setup and what the organisations is looking to achieve with its digital transformation strategy will therefore have an immediate impact on the cybersecurity strategy.
Despite this, there are fundamentals that any organisation should implement:
Review and test your back-up policy to ensure it is thorough and sufficient – By checking that the organisation’s back-up is running smoothly, IT teams can limit any risks of disruption in the midst of an incident and of losing data permanently.
In our recent State of Email Security report, we found that six out of ten organisations have been victims of ransomware in 2020. As a result, afflicted organisations have lost an average of six days to downtime. One third of organisations even admitted that they failed to get their data back, despite paying the ransom. In the healthcare industry, this could mean losing valuable patient records or data related to new treatments – two areas the sector cannot afford to be cavalier about.
Conduct due diligence across the organisation’s supply chain – Healthcare organisations should review their ways of working with partners, providers and regulatory institutions they work with in order to prevent any weak link in their cybersecurity chain. Without this due diligence, organisations leave themselves exposed to the risks of third party-led incidents.
Roll out mandatory cybersecurity awareness training - Healthcare organisations shouldn’t neglect the training and awareness of their entire staff – including frontline workers who may not access the corporate network on a regular basis. According to our State of Email Security report, only one fifth of organisations carry out ongoing cyber awareness training.
This suggests it is not widely considered as a fundamental part of most organisations cyber-resilience strategy, despite the fact many employees rely on their organisation’s corporate network to work. By providing systematic training, healthcare organisations can help workers at all levels better understand the current cyberthreats they face, how they could impact their organisation, the role they play in defending the networks, and develop consistent, good cybersecurity hygiene habits to limit the risks of incidents.
Consider a degree of separation – Information and Operational Technology (IT and OT) networks should be separated.
Although mutually supported and reliance on each other, employees shouldn’t be accessing one via the other. This should be complemented by a considered tried and tested contingency and resiliency plan that allows crucial services to function unabated should there be a compromise. Similarly, admin terminals should not have internet access to afford a degree of hardening and protection for these critical accounts.
As the sector becomes a common target for fraudulent and malicious activity, putting cybersecurity at the core of the organisation’s operations is critical. It will help limit the risks of disruption due to cyberattacks, reduce time spent by the cybersecurity team to resolve easily avoidable errors, and ensure that institutions can deliver patient care, safe in the knowledge that their networks are safe.
Fighting future threats
With technology continuing to change the face of healthcare, the surface area and vectors available for attacks by malicious actors is constantly increasing. With the introduction of apps, networked monitoring devices, and a need for communication, the attack vector is ever expanding, a trend that needs to be monitored and secured against.
To prevent any damage to patients, staff, or the organisation they are responsible for, healthcare leaders must put security front and centre of their digital transformation strategy. Only then can the sector harness the full benefits of technology. Doing this should include implementing cybersecurity awareness training to challenge misconceptions around security, encourage conversation, and to ensure employee knowledge of the security basics and threats faced.
This ultimately allows healthcare organisations to do what they do best: provide the highest standard of patient care, safe in the knowledge that their operations, patients, and data are safe.