Medical explainers
Medical explainers
Plain-English medical explainers covering the mechanisms, conditions and methodologies that feature in the Letby case. Each page links to the comprehensive source-linked evidence material on this site.
Air embolism (neonatal) — plain-English explainer
What air embolism is, the Lee & Tanswell 1989 paper, and why the diagnostic basis for the air-embolism counts in the Lucy Letby case is contested by the paper's author.
Insulin and C-peptide — plain-English explainer
Why endogenous and exogenous insulin can be distinguished by C-peptide ratio, why the immunoassay used in the Letby case is contested, and what mass-spectrometry confirmation would have added.
Why preterm babies collapse — the natural-cause differential
Plain-English summary of the established natural causes of sudden collapse in preterm and unstable neonates: sepsis, NEC, IVH, PDA, PPHN, tube displacement and resuscitation events.
Neonatal sepsis — plain-English explainer
What neonatal sepsis is, how it presents, why it is in the natural-cause differential for unexpected collapse, and how it features in the post-conviction expert reading of the Letby cases.
Necrotising enterocolitis (NEC) — plain-English explainer
What necrotising enterocolitis is, why it produces radiological findings that can resemble those described in the Letby case, and how it features in the post-conviction expert review.
Prematurity, gestational age and clinical fragility
How gestational age maps to expected outcomes in preterm babies, and why the Countess of Chester Hospital's level-2 designation matters to the evidential reading of the indicted cases.
Total parenteral nutrition (TPN) — plain-English explainer
What TPN is, how TPN bags are prepared, and how TPN features in the Letby case as one of the mechanisms the prosecution alleged.
Neonatal hypoglycaemia — plain-English explainer
Why neonatal hypoglycaemia has natural causes that must be excluded before exogenous insulin is inferred, and why immunoassay results require confirmatory testing.
Immunoassay vs mass spectrometry — why the method matters
Why insulin immunoassays are screening tools, why forensic determination requires mass spectrometry, and why this matters for the Letby insulin counts.
Resuscitation artefacts — why CPR can mimic injury
Why neonatal resuscitation can produce post-mortem and clinical findings that look like trauma, and why this matters in the Letby cases.
Liver-injury differential in newborns
The medical differential for hepatic injury findings in newborns: resuscitation, sepsis, coagulopathy, and the post-conviction reading of the indicted cases.
Skin mottling in collapsing neonates — what it does and does not show
Why skin mottling is a non-specific sign in collapsing newborns and why it cannot itself diagnose air embolism.
Ventilation, ET tubes and tube displacement
Why ET-tube displacement is the default clinical assumption when a preterm baby deteriorates unexpectedly, and how this bears on the Child K count.
Twin-to-twin transfusion syndrome (TTTS)
What TTTS is, how it presents in monochorionic twins, and how the Letby twin cases are reread in light of TTTS.
Monochorionic twins — shared-placenta risks
Why monochorionic twins carry shared-placenta complications that affect post-delivery stability, and how this bears on the Letby twin cases.
Neonatal unit acuity and staffing — what 'operating beyond capability' means
Why unit acuity and staffing are part of the evidential picture in the Letby case, even though hospital failings do not by themselves prove innocence.