High operation and maintenance cost, lower quality of oxygen generated, and fear of antagonising the regular liquid medical oxygen suppliers have kept hospitals from using pressure-swing adsorption (PSA) plants routinely, and a senior official of the Health ministry now calls them “white elephants”.
A year since the Covid-induced oxygen crisis, most hospitals have taken to switching on the plant once a week or for a couple of hours every day to ensure that the machine remains functional.
Even so, more hospitals continue to invest in the expensive machinery, with the Delhi government ordering all hospitals to enhance its oxygen generation capacity – 100-bed hospitals have been asked to create capacity for double their usual need, 50 to 99 bed hospitals have been asked to create capacity at least for their usual need, and others to just enhance their infrastructure – on orders of the Delhi High Court.
There was a deficit of 243 MT (metric tonne) PSA plant capacity across 58 private hospitals with 100 or more beds, according to a Delhi government order.
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A pressure-swing adsorption plant essentially removes nitrogen, carbon dioxide, and other gases from the ambient air to produce concentrated oxygen.
A plant with the capacity of generating 1,050 litres of oxygen per minute was installed in Delhi government’s GB Pant Hospital last month. Moolchand Hospital installed a slightly different vacuum-swing adsorption plant in April. The Holy Family Hospital started operating its plant around three months ago.
“The nursing home cell of the Delhi government asks hospitals to install the plant. The plant might have helped at the peak of the second wave, but we will probably not require as much oxygen until another pandemic happens. The machines might just lie in disrepair,” said a private hospital operator.
At least 3,756 PSA plants were commissioned in the country until March this year, according to a reply in Lok Sabha by Minister of State for Health Dr Bharati Pravin Pawar.
Hospitals, even the ones who received their PSA plants as donations from international organisations or corporates, say that running the plants is a costly affair.
“We have been using the PSA plant and liquid medical oxygen (LMO) simultaneously. It has certainly reduced the amount of LMO we use – earlier we had to fill our tank every five to seven days, now it lasts about 15 days. But, what is the point? Under normal circumstances, it costs me around Rs 1.25 lakh to purchase the amount of LMO needed as compared to Rs 2.5 lakh electricity bill that I have to pay for running the PSA plant,” a senior administrative official of a 300-bed hospital in Delhi said, adding that they will soon switch to a couple of hours a day schedule.
The plant can, at best, be kept as a backup in case there is a surge in demand as seen during the second wave, the administrator said.
The owner of another 100-bed hospital said, “If I run the PSA plant round the clock, the cost of electricity comes to about Rs 2.3 lakh. Of course, the plant produces 250 litres of oxygen per minute. I need about 55 to 60 litres, which I can purchase for Rs 80,000-90,000. If I want to store the excess oxygen produced, I have to shell out another Rs 25 lakh for a machine that can pressurise the oxygen to fill in the cylinders. But, how many cylinders can I fill?” The owner spent Rs 40 lakh to install the machine.
Space to set up the plants and the loud noise in industrial areas also work against hospitals utilising the plants, he said.
“Also, if I start depending on the PSA plant completely – and that is not really possible – why would the LMO suppliers give me any oxygen at the time of need instead of their regular customers?” he said.
This is the fear that another big city hospital faces. “We do not want to antagonise the LMO suppliers who have been providing oxygen to us for years,” said a hospital personnel.
The government’s Guru Teg Bahadur Hospital, which has two PSA plants totalling a capacity of 3,000 litres per minute, runs the plant around four times a week between 9 am and 1 pm.
“As our oxygen consumption is high, we have the PSA plant and the LMO connected to the same line. This reduces the amount of LMO consumed and the pressure drop is less,” according to an official from the hospital. However, even with the plant operating only for a few hours, the cost of oxygen has remained largely unchanged for the hospital. This “cost” does not account for any additional manpower needed.
The personnel from the big private hospital said they need to retain biomedical engineers for running and maintaining the plant, which adds to the cost of running the plant.
Even if the cost factor is overlooked, the hospitals say there are several technical challenges with the PSA plants. Unlike LMO which is 99% pure oxygen, the purity of the oxygen produced by the PSA plants is about 93% (+/- 3%).
“And, the plant can reach that level of purity only after running for 30 to 40 minutes when it produces anywhere between 40% to 60% pure oxygen, which is of no medical use. This means, I cannot switch it on and start using the oxygen immediately in case there is an emergency. Plus, I will always need to have a back-up LMO to tide over technical issues,” said the owner of the 100-bed hospital.
In addition, even the purest form of oxygen generated by the plant cannot be used for highly oxygen-dependent patients.
“The LMO is 99% pure oxygen whereas the oxygen from the PSA plant is about 93%, so we have to calibrate all our masks and machines accordingly. For example, a ventilator has a mixing chamber that uses the pure oxygen along with the room air depending on the saturation that is set. The risk with PSA oxygen is that we might think we are giving someone 40% oxygen when we are just giving them 33%,” the administrator from the 300-bed hospital said.
The oxygen crisis during the second wave of the pandemic was largely a logistical issue rather than oxygen production. First, the Centre could not anticipate the sudden increase in the need for oxygen – by the time Delhi’s allocation was increased to 590MT, the state government said that the requirement had gone up to 700MT in May beginning last year.
Second, there is no cryogenic oxygen plant (that separates the other gases from air by cooling it down) for generating liquid medical oxygen within the state border. And tankers carrying oxygen from neighbouring states were being stopped by local administration to ensure adequate supply for their states.Third, the LMO allocation for Delhi happened from places like Odisha, Jharkhand, and West Bengal from where there were no existing supply chains to Delhi. Fourth, even when the oxygen was brought on trains, Delhi did not have enough tankers to decant it and ensure that it reached the hospitals.
Delhi has since bought new tankers, created regional buffer tanks of 442MT capacity, purchased 6,000 big D-type cylinders, and set up two cryogenic oxygen plants.
Asking hospitals to set up cryogenic plants was a knee-jerk reaction after the devastating second wave. Had the logistics been in place at the time, this would never have happened. Now, the hospitals are stuck with these plants. It may be useful in say a district hospital or a primary health centre where the oxygen supply chain may not be strong. But in a city like Delhi where LMO is readily available, PSA plants are of no use,” said the administrator of the 300-bed hospital.
Senior government officials said the executive order to install PSA plants was based on directions of the court. “In any case, we cannot anticipate when there is a surge in Covid-19 cases again. We have to be prepared on a war footing. Covid has gone down but it hasn’t gone away,” said an official.
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