To be fair, noting this infamous Toronto case.
The baby killer at Toronto's Sick Kids was rubber - Macleans.ca
The baby killer at Toronto’s Sick Kids was rubber
The real culprit for a wave of deaths in the early 1980s was a compound found in seals on IVs and syringes
by
Brian Bethune
Dec 22, 2011
"Between June 1980 and March 1981, baby deaths spiked 625 per cent at Sick Kids’ cardiac unit—43 cases in all. Autopsies belatedly performed as death inexorably followed upon death seemed to show poisonous levels of digoxin. Investigators focused on Nelles, because she was (apparently) on duty for 24 of the deaths, and because she had the temerity to ask for a lawyer. Later, the Grange inquiry managed to cast a lifelong cloud of suspicion over another nurse, Phyllis Trayner (now dead), while ruling eight of the deaths as murders.
So what really happened to those children? A cluster of factors, according to Hamilton. They were very sick, and it took only the tiniest of nudges—natural or deliberate—to push them across death’s threshold. And that push was coming with increasing force. MBT, a chemical compound in the rubber seals used in IV lines and disposable plastic syringes, was leeching into the contents of those devices, bringing chances of life-threatening anaphylactic shock—which is how Hamilton, a radiologist from London, Ont., encountered it—and of death by accumulated toxins. The problem grew, unseen, as the era of unit-dose syringes dawned around 1980. Designed to eliminate overdose errors, prepackaged unit doses had three-year shelf lives—all the longer for the MBT to leech into the contents.
The smallest, most fragile patients, the cardiac babies, were most at risk: more injections, more transfusions, more poison, more chances of crossing the threshold. And if circumstances were cruelly conspiring against the children, so too were they taking aim at the accused nurses. The tests used to measure the digoxin levels in the autopsied babies were less than useless. They consistently misread MBT as digoxin, and failed to take into account that digoxin in the hearts of cardiac patients spreads through the body postmortem, giving a false reading of how much was present during life."