In this post I will outline evidence which, in my view, establishes beyond doubt that Lucy Letby could not have injected insulin into a stock TPN bag while it was in storage. That was the allegation in the case of Baby F, because the bag in question was taken from storage and administered several hours after Letby had gone off duty.
Here I examine the type of tamper-evident cap that would have been present over the additive port of that stock TPN bag—and it’s not the type implied by the prosecution.
During the trial, pharmacist Ian Allen stated that the safety cap protecting the additive port of a neonatal TPN bag could be removed and replaced without leaving any visible sign of tampering. (I have already pointed out in the post below that Nick Johnson KC appeared to accept that this could not be done while the bag was still contained within its outer cellophane pouch.)
However, there is an even greater flaw in the prosecution's argument. It’s clear from Ian Allen's testimony that the safety cap he described as removable was the type fitted by the hospital pharmacy when preparing a prescription bag. By contrast, the off-the-shelf stock TPN bag allegedly spiked by Lucy Letby while in storage would have been fitted with the manufacturer's original plastic safety cap over the additive port—the type Ian Allen described in his testimony as "tamper-proof". These have plastic tabs that have to be be snapped off to gain access to the additive port; once removed, they cannot be put back.
This distinction was never made during the trial, yet the difference is clear from Ian Allen's testimony. There would have been no way for Lucy Letby to inject insulin into the stock Babiven Maintenance TPN bag without leaving clear signs of tampering. The manufacturer's safety tab protecting the additive port would have had to be broken off—something that could not be missed when hanging the bag. This task involves two nurses who carefully inspect the bags for integrity before hanging them. No nurse would use a TPN bag with a broken seal or any sort of defect to its outer wrap, even if it had been caused accidentally—in which case there would be a serious risk of infection.
The suggestion that a major manufacturer was supplying the NHS with neonatal TPN bags fitted with ineffective security seals is implausible. These products are subject to international standards, while the NHS has its own safety requirements. It makes far more sense that any issue with the safety caps related only to those replacement caps used locally by the Countess of Chester Hospital.
I suspect that when Ian Allen's evidence was prepared, he had not been told that the prosecution would be alleging that an off-the-shelf Babiven Maintenance TPN bag had been injected with insulin while in storage. Nor was he specifically asked about that scenario during the trial. Had he been asked, it’s likely that this would have highlighted the fact that access to the additive port of an off-the-shelf Babiven Maintenance TPN bag would have required breaking off the manufacturer's tamper-evident tab.
In his testimony, Ian Allen explained that off-the-shelf Babiven Maintenance TPN bags were used in the NNU without alteration, or they could be tailored to specific prescriptions in the hospital’s pharmacy by adding the prescribed vitamins and trace elements to them. This was done by snapping off the manufacturer’s safety cap covering the additive port, injecting the prescribed vitamins and trace elements through its self-sealing rubber bung, and then recapping the port with their own safety cap.
Extracts of Ian Allen’s trial testimony are shown below, with my comments in square brackets.
IA = Ian Allen, SD = Prosecutor Simon Driver
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SD: So Babiven Start-up. We understand, could you confirm, if you agree, that that would be used for babies during the first day or two of life?
IA: That's correct, yes: for the first 2 days of life, the baby received Babiven Start-up.
SD: A second type of, if I might call it off-the-shelf TPN bag, you've already described as a Maintenance bag. And both of those, is this right, would be supplied to the unit through your department but without your department in any way adulterating the contents of the bag?
IA: Yes. So Babiven Maintenance -- there would be Babiven Maintenance bags sent to stock, which we would not add anything to the bag. But also we would supply Babiven Maintenance with vitamins and trace elements. The difference being that it takes a little time to process an order from the pharmacy, so the ward might use the Babiven Maintenance without the vitamins and trace elements to start, but then once they had sent the order to the pharmacy, the baby would move on to have the bag with the vitamins and trace elements from that point forward.
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A video created by the Countess of Chester pharmacy team was played to the court demonstrating the procedure for making up prescription bags using off-the-shelf Babiven Maintenance bags. The video was paused, and Ian Allen was asked :
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SD: Pausing there. So the narrator said she was removing the safety cap from which port?
IA: The additive port. So the additive port is a tamper-evident safety cap which is made of preformed plastic which you snap away. [The manufacturer’s safety cap] That then allows the person to add additions to the bag via that port.
SD: So the safety cap having been snapped away, what lies below?
IA: It is a bung or a septum, which you can insert a needle through. Once you push the needle through you can add to the bag, but then as you pull off that bung will self-seal over so the bag doesn't leak and the container is again closed.
SD: So that central port is the additive port?
IA: That's correct.
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Later, the video was paused again:
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SD: Pausing there, please, Mr Allen. We saw the operative or the pharmacist add ingredients through the additive port and then she covered it with what she described as a safety cap. [The replacement safety cap.] That having been reapplied, is it fixed or can it be removed again?
IA: When we tested on the bags subsequently, it can be removed and attached over that port.
SD: Thank you. Could we continue, please?
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The video continued before being paused again:
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SD: Pausing there. You agree that's the additive port?
IA: That's correct, yes.
SD: Do you agree it's tamper-proof?
IA: That cap is not tamper-proof that's on there now. [The replacement safety cap] It could be removed when we test it.
SD: If I were to give you a bag now, could you demonstrate that?
IA: Yes.
SD: Thank you.
(Pause)
IA: So I'll try and hold it up. The additive port is in the middle. You can snap off the piece of plastic which is tamper-proof. [The manufacturer’s safety cap] We then add to the bag.
Mr Justice Goss: Would you mind standing up so everyone can see?
IA: I have just snapped off the tamper-proof small piece of plastic [The manufacturer’s safety cap] which exposes the additive port. This is the cap then, once the operators have added to the bag, they place it over the additive port. [The replacement safety cap] And it does click on, but it's possible to actually pull off when we tested it previously. It does come back off. It has small plastic ridges which hold it in place, but if you want to pull it off, it can be pulled off.
SD: And beneath that lies something you described as a bung earlier, a self-sealing rubber stopper?
IA: Yes, a self-sealing rubber stopper through which the additives have been inserted into the bag.
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In response to questions from the judge, Ian Allen confirmed that the manufacturer's standard Babiven Maintenance bags were supplied to the neonatal unit without any modification by the pharmacy:
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Mr Justice Goss: The other question is this: we've heard about -- these are prescribed bags that are then sent down from the neonatal unit. We have heard about ready made-up bags that are kept in stock --
IA: Yes.
Mr Justice Goss: -- in the fridge in the unit.
IA: Yes.
Mr Justice Goss: Right. Do they just get sent down at any time?
IA: The ready made-up bags?
Mr Justice Goss: Yes.
IA: So they would have a stock level on the neonatal unit of a certain amount of bags. As they became low, because they've been used up, they would request some from the pharmacy and we would send them more as stock. So we would not manipulate those bags, they are just off the shelf from the manufacturer, sent to the neonatal unit, and placed into the fridge.
Mr Justice Goss: You just store them until they request them basically?
IA: Yes, we are simply kind of an intermediary: we receive them from the manufacturer, we have a big fridge to store them in, the bulk of the stock. Then we send them up in small amounts to the smaller fridge in the neonatal unit.
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As noted above, these off-the-shelf Babiven Maintenance TPN bags are the very same bags used as the the base for preparing prescription bags. They are supplied with the manufacturer’s snap-off safety cap that Ian Allen demonstrated in court and described as "tamper-proof".
Yet it was a bag in precisely this configuration that the prosecution alleged Lucy Letby injected with insulin: the manufacturer's tamper-evident safety tab still in place and the bag enclosed within its protective cellophane pouch. It’s simply not possible to tamper with these bags while leaving the tamper-evident protections intact.
In my view, this constitutes incontrovertible evidence that Lucy Letby could not have injected insulin into a stock Babiven Maintenance TPN bag while it was in storage—the bag that was subsequently administered to Baby F several hours after Letby had gone off duty. It was this bag that was alleged to have been the source of the excess insulin in Baby F's bloodstream, as indicated by the blood test performed later that day.
Whatever the explanation for that elevated insulin reading, Letby was not present in the hospital during that shift, and could not have been responsible for contaminating that stock Babiven TPN bag while it was in storage and still protected by the manufacturer's tamper-evident seals,
(The video attached to this post shows a TPN bag for adults and older children supplied by Fresenius Kabi, the same manufacturer that supplies Babiven Maintenance TPN bags to the NHS, and it uses the same type of ports. The video includes a demonstration of the snap-off Additive port safety cap.)
Thanks to Sofie Terleska for supplying Ian Allen's testimony at the following link:
teddit.net/r/LucyLetbyTrials…