Overcoming oxygen supply issues

PATIENTS made severely ill may have difficulty breathing and require treatment with machines such as ventilators to supply them with oxygen. This has led to mounting global concerns about providing sufficient oxygen supply and treatment equipment.

“The issue at the moment is not about the oxygen supply, it is about the sizing of the equipment [that supplies the oxygen] in the hospital,” says Zeb Ahmed, the Workstream Lead covering Hospital Supplies for IChemE’s Covid-19 Response Team.

Due to coronavirus, the number of people needing hospital treatment has increased above peak flow, which is the maximum number of patients expected to require oxygen, explains Ahmed. As a result, “you’ll find that the infrastructure in the hospital is too small to accommodate for the number of patients, and the simultaneous usage.”

According to Ahmed, key industrial challenges involved in the supply of oxygen are “the [limited] availability, and the production time to get the VIE of the appropriate size for the increased hospital need”. VIEs, or vacuum insulated evaporators, are pressure vessels for bulk storage of cryogenic liquids including oxygen for industrial processes and medical applications. For medical use, they are made bespoke and installed at the hospital.

VIEs typically supplied to hospitals are too small to meet current demand, says Ahmed. To overcome this challenge, industry is prioritising and accelerating fabrication times. Typical fabrication takes “anywhere from circa six weeks – very fast – to 12 to 16 weeks – normal, he explains.”

According to Ahmed, VIEs currently seem to be the “single biggest bottleneck” to supply. However, oxygen can also be delivered in smaller scale cylinders. To help meet oxygen demand, Air Liquide has increased production and supply of oxygen cylinders and is working with hospitals and healthcare facilities to ensure that once cylinders are empty, they are returned to the company’s facilities to be refilled.

Another infrastructure issue is that the pipes in hospitals that direct oxygen to patients are insufficiently sized to supply the surge in simultaneous demand, Ahmed explains. Based on the new demand, existing headers – the main pipe going from VIEs to the hospital – are undersized. New headers being installed due to the crisis are larger, to enable sufficient oxygen flow to ventilators. Headers are now being designed to meet the increased surge capacity, or above, to account for potential future increases.

There have also been issues with the availability of degreased copper – used to produce the medical grade oxygen pipework – as well as a shortage of certified workers to install the piping. According to Ahmed, one method to overcome this challenge is to use stainless steel, which is used by the pharmaceutical industry and more readily available than degreased copper. This increases access to materials, as well as workers able to install it.

IChemE’s Covid-19 Response Team is to act as an independent, professional intermediary between suppliers and healthcare, helping to identify the correct solutions to the industrial scale challenges that healthcare is now facing due to the coronavirus. The team has several workstreams, and in his role Ahmed is responsible for oxygen, ventilators, and personnel protective equipment.

Ahmed commented: “There’s a whole host of areas we’re looking at as IChemE, and that really reflects the diversity and the significance of chemical engineers within this overall situation.”

Separately, IChemE’s Pharma Special Interest Group (SIG) has called for members to come forward and help supply ventilators and ventilator components following a request from the UK Government.