UK - Nurse Lucy Letby Faces 22 Charges - 7 Murder/15 Attempted Murder of Babies #12

[GoodDayToYouSir]

"A medical expert told Manchester Crown Court that the youngster, Child L, suffered a hypoglycaemic episode which lasted from the morning of April 9 2016 to the middle of the afternoon on April 11."

[...]

Jurors heard the dextrose concentration was increased as medics tried to bring Child L’s blood sugar levels up – which necessitated a change of bag – and the rate of infusion was also stepped up.

Prof Hindmarsh said despite that there was “not really much change in the glucose measurements which would imply there was ongoing insulin present and ongoing insulin action”.

He told the court that insulin could “potentially” have been added to at least three dextrose bags if the giving sets were also changed.

Prof Hindmarsh also raised the possibility that if the giving set remained the same then insulin could stick to its plastic, come off and then release into the bag.

He agreed with Ben Myers KC, defending, that “sticky insulin” would eventually run out."

Mr Myers asked: “It is the case that sticky insulin could be operative over a similar period?”

Prof Hindmarsh replied: “I don’t think anyone has done this sort of study to be honest. I think the answer is I don’t know.”

He told Mr Myers the “relatively steady” blood sugar levels did not seem to be influenced by the increased infusion rates.

Mr Myers asked: “Would that be more consistent with it being added to the bag as you go on, rather than the sticky insulin?”

Prof Hindmarsh replied: “Yes.”

[...]

more to read at links (PA)
Evening Standard - Baby had dangerously low blood sugar levels over three days, Letby trial told
Independent - Baby had dangerously low blood sugar levels over three days, Letby trial told
Belfast Telegraph - Baby had dangerously low blood sugar levels over three days, Letby trial told

Can someone explain what “sticky insulin “ is please? What are the other types of insulin ? When would you use different types?

 

[ColourPurple]

It’s the issue they talked about in opening speeches. The idea that insulin gets stuck on the plastic lines/tubes of the machine, and therefore keeps seeping into the child even after the poisoned bag is removed.

At the time I was hoping they would have actually tested this on a machine to recreate it, but looks like they have not.

I'm wondering if rather than insulin being added to the bag and some sticking to the plastic of the giving set and continuing to be released... whether there would be some way to just add the insulin directly to the giving set, possibly in much higher amounts so that it carries on releasing insulin over a massively long period of time, even when bags are changed

I know the answer is going to be that nobody has ever done those kind of experiments, but it doesnt stop me wondering.

Any nurses know whether it would be possible to just contaminate the giving set with insulin rather than injecting it into the bags themselves?

 

[Sweeper2000]

Can someone explain what “sticky insulin “ is please? What are the other types of insulin ? When would you use different types?

There isn’t a type of insulin called sticky insulin it’s just that insulin as a liquid sticks to the plastic used in the equipment specifically the bags holding liquid. So if someone puts insulin in with the dextrose liquid it sticks to the plastic. Same way treacle sticks to a wall.

 

[JosieJo]

So he was receiving 10% glucose on the morning of 9th April, LL's day shift - this is when the contamination started.
The blood sample was taken for the lab at 3.35pm.
He was put on 12.5% dextrose at 4.30pm that same shift. LL was still at work at 9.22pm that evening.
He was put on 15% dextrose at 6am that night shift 9th/10th.
His blood sugars came up to 3.0 by 2pm on 10th but then fell back again and didn't come back up to above 3.0 until 3pm on 11th.

So the first two bags were applied during LL's shift, and the last was applied on the night shift following her day shift.

That's what we were told in the electronic evidence. I don't know how many additional boluses of glucose might have been administered at different times, seems there might be gaps in the reporting. JMO

Sorry I know you always get the questions ..was LL on the following days shift after the 3rd bag went up at 6am

 

[marynnu]

I'm wondering if rather than insulin being added to the bag and some sticking to the plastic of the giving set and continuing to be released... whether there would be some way to just add the insulin directly to the giving set, possibly in much higher amounts so that it carries on releasing insulin over a massively long period of time, even when bags are changed

I know the answer is going to be that nobody has ever done those kind of experiments, but it doesnt stop me wondering.

Any nurses know whether it would be possible to just contaminate the giving set with insulin rather than the inject it into the bags themselves?

IMO I'm not sure it's physically possible, at least not realistically. There's a long length of tubing till you get fairly near to the baby, with nowhere to inject. And if you planned to do this I don't think it would be the first thing that came to mind. JMO

 

[magikarpmagikarp]

I'm wondering if rather than insulin being added to the bag and some sticking to the plastic of the giving set and continuing to be released... whether there would be some way to just add the insulin directly to the giving set, possibly in much higher amounts so that it carries on releasing insulin over a massively long period of time, even when bags are changed

I know the answer is going to be that nobody has ever done those kind of experiments, but it doesnt stop me wondering.

Any nurses know whether it would be possible to just contaminate the giving set with insulin rather than the inject it into the bags themselves?

If only the bag was changed and not the giving set, then whatever was left in the giving set was still full of insulin. The priming volume of our giving sets is 22 mL, so if you do not change the set (or re-prime it), then it can take hours or even days (depending on the rate of infusion) for the new fluid to reach the baby. Over here, we only re-spike a bag if it is identical; if it's a new concentration or formulation, it gets a new set. JMO.

I've also wondered if anyone really knows how long it would take for a massive dose of insulin to clear even if it wasn't being given continuously. Regardless, I think they've established that the baby was poisoned with insulin - no one seems to dispute that. In general, does anyone know how important is it to the prosecution's case to determine the exact route?

 

[ColourPurple]

IMO I'm not sure it's physically possible, at least not realistically. There's a long length of tubing till you get fairly near to the baby, with nowhere to inject. And if you planned to do this I don't think it would be the first thing that came to mind. JMO

Thank you. So you wouldn't be able to inject the insulin directly into the tube from either end of it ? Are the bits at each end of it removable?

I agree that it'd be easer to just put it into the bag.

 

[Sweeper2000]

I’m really not getting this today. just assuming that again it seems more than one bag has been contaminated and this time with an amount of insulin that exceeded the previous case does that again leave us asking the question of just how much insulin would be necessary to have contaminated the bags and was there enough on the ward for that to have been done there?

 

[magikarpmagikarp]

So you wouldn't be able to inject the insulin directly into the tube from either end of it ? Are the bits at each end of it removable?

I agree that it'd be easer to just put it into the bag.

Some bags giving sets have a little port on them to add a "piggyback" fluid; some don't have these ports. I guess someone really determined could take a small needle and try to add fluid into the priming chamber, but it might get leaky, and unlike other types of access to the line, there is nothing legitimate appearing about like that. Also, unlike having fluid left over in the giving set that continues to run for hours even after the new bag is put on, if you put insulin in the giving set at the start, I'm not convinced it would last over multiple shifts, unless it was running at less than 2mL/ hour. (Which it might have been!) I do think it's a stretch, but tht's JMO.

 

[ColourPurple]

If only the bag was changed and not the giving set, then whatever was left in the giving set was still full of insulin. The priming volume of our giving sets is 22 mL, so if you do not change the set (or re-prime it), then it can take hours or even days (depending on the rate of infusion) for the new fluid to reach the baby. Over here, we only re-spike a bag if it is identical; if it's a new concentration or formulation, it gets a new set. JMO.


I've also wondered if anyone really knows how long it would take for a massive dose of insulin to clear even if it wasn't being given continuously. Regardless, I think they've established that the baby was poisoned with insulin - no one seems to dispute that. In general, does anyone know how important is it to the prosecution's case to determine the exact route?

Thanks. So it's theoretically possible that the giving set might have stayed contaminated and carried on releasing enough insulin to keep both babies' blood sugars low even when a contaminated bag was changed for an uncontaminated one.

Like you I'm wondering what would happen if somebody had just added a massive amount, like the whole bottle of insulin.

 

[magikarpmagikarp]

I’m really not getting this today. just assuming that again it seems more than one bag has been contaminated and this time with an amount of insulin that exceeded the previous case does that again leave us asking the question of just how much insulin would be necessary to have contaminated the bags and was there enough on the ward for that to have been done there?

Where else do you think it would have been done?

 

[marynnu]

Thank you. So you wouldn't be able to inject the insulin directly into the tube from either end of it ? Are the bits at each end of it removable?

I agree that it'd be easer to just put it into the bag.

You cold inject it into the port near the baby, but it would infuse quickly then be gone. To inject into the top you'd have to do it into the empty set before connecting to the bag, disconnect from the bag after the fluid was run through or pierce the tubing - but that would leak. Personally I don't see the point of it.

 

[marynnu]

If only the bag was changed and not the giving set, then whatever was left in the giving set was still full of insulin. The priming volume of our giving sets is 22 mL, so if you do not change the set (or re-prime it), then it can take hours or even days (depending on the rate of infusion) for the new fluid to reach the baby. Over here, we only re-spike a bag if it is identical; if it's a new concentration or formulation, it gets a new set. JMO.

I've also wondered if anyone really knows how long it would take for a massive dose of insulin to clear even if it wasn't being given continuously. Regardless, I think they've established that the baby was poisoned with insulin - no one seems to dispute that. In general, does anyone know how important is it to the prosecution's case to determine the exact route?

Where I worked if we made a change like this that we wanted to have an immediate effect, we'd run the new solution through the giving set then reconnect, fot the reasons you state.

 

[marynnu]

I wonder if an experiment has been done adding a large dose of insulin to a bag, running it for several hours as you would with an infusion, then replacing the bag to see if the insulin sticks to the tubing? For me, I'd be surprised if they haven't as it would be pretty simple, I think.

 

[ColourPurple]

Some bags giving sets have a little port on them to add a "piggyback" fluid; some don't have these ports. I guess someone really determined could take a small needle and try to add fluid into the priming chamber, but it might get leaky, and unlike other types of access to the line, there is nothing legitimate appearing about like that. Also, unlike having fluid left over in the giving set that continues to run for hours even after the new bag is put on, if you put insulin in the giving set at the start, I'm not convinced it would last over multiple shifts, unless it was running at less than 2mL/ hour. (Which it might have been!) I do think it's a stretch, but tht's JMO.

You cold inject it into the port near the baby, but it would infuse quickly then be gone. To inject into the top you'd have to do it into the empty set before connecting to the bag, disconnect from the bag after the fluid was run through or pierce the tubing - but that would leak. Personally I don't see the point of it.

Thanks both. So basically it would be very hard/messy to try to do, with no guarantee that it would work, and much easier to jsut put insulin in the bag.

 

[Supernovae]

If only the bag was changed and not the giving set, then whatever was left in the giving set was still full of insulin. The priming volume of our giving sets is 22 mL, so if you do not change the set (or re-prime it), then it can take hours or even days (depending on the rate of infusion) for the new fluid to reach the baby. Over here, we only re-spike a bag if it is identical; if it's a new concentration or formulation, it gets a new set. JMO.

I've also wondered if anyone really knows how long it would take for a massive dose of insulin to clear even if it wasn't being given continuously. Regardless, I think they've established that the baby was poisoned with insulin - no one seems to dispute that. In general, does anyone know how important is it to the prosecution's case to determine the exact route?

Theoretically it could effect the pool of potential perpetrators. When I saw this on Dan O'Donoghue's twitter account I presumed that it would be harmful for her, as the need for repeated contamination would at least significantly reduce the pool of alternative perpetrators, but Ben Myers' line of questioning seems to suggest that he thinks this is better for her than insulin sticking to the giving set.

 

[marynnu]

If only the bag was changed and not the giving set, then whatever was left in the giving set was still full of insulin. The priming volume of our giving sets is 22 mL, so if you do not change the set (or re-prime it), then it can take hours or even days (depending on the rate of infusion) for the new fluid to reach the baby. Over here, we only re-spike a bag if it is identical; if it's a new concentration or formulation, it gets a new set. JMO.

I've also wondered if anyone really knows how long it would take for a massive dose of insulin to clear even if it wasn't being given continuously. Regardless, I think they've established that the baby was poisoned with insulin - no one seems to dispute that. In general, does anyone know how important is it to the prosecution's case to determine the exact route?

If you mean how long to clear from the baby, I've wondered that too. Like, when the level is off the scale, is there any mechanism by which it gets absorbed into the tissues to be released slowly later? And how efficient are the kidneys, especially preterm ones, in excreting such a large amount? All my own ramblings & speculation!!

 

[magikarpmagikarp]

If you mean how long to clear from the baby, I've wondered that too. Like, when the level is off the scale, is there any mechanism by which it gets absorbed into the tissues to be released slowly later? And how efficient are the kidneys, especially preterm ones, in excreting such a large amount? All my own ramblings & speculation!!

I read a little about about intentional overdoses in adults and apparently it can take several days of intensive care and high concentration dextrose for blood sugars to normalize in adults after a single OD. I have no idea how that would apply to babies, though. It sounds like Professor Hindmarsh doesn't think it's likely.

 

[Tortoise]

Sorry I know you always get the questions ..was LL on the following days shift after the 3rd bag went up at 6am

No, that was the Saturday she won the grand national. She went home after 9pm and they messaged her the next morning (Sunday) to see if she could do an extra shift that night but she said no, she needed some time off. She was off until the Thursday.

 

[magikarpmagikarp]

Oh, @Sweeper2000 this article states that Dr. Hindmarsh believes it would take 1.8 units of insulin per hour to have caused the blood sugars seen for baby H. If whole vials of insulin are 1000 units in 10 mL then adding a whole vial to a 500 mL bag would require an infusion rate of only 0.9 mL/hr to provide that amount of insulin, using simple unit conversions. It sounds like a partial vial could easily have been added to the bag to have the same effect. JMO.

Nurse Lucy Letby 'poisoned baby by contaminating two intravenous bags'

Neonatal nurse Lucy Letby poisoned a baby boy by contaminating two bags of intravenous feed with insulin that could not be detected by the human eye, a court heard today.

www.dailymail.co.uk