Kaplan Meier survival curve for control and acetaminophen injured pigs. (A) The control group (Group 0) as demonstrated by the uninterrupted line all survived, and indeed appeared healthy when euthanased. The injury group (Group 1) as demonstrated by the interrupted line died as denoted in the Kaplan-Meier curve. Two animals* were euthanased at 25 hours as they appeared particularly unwell, and another further two were euthanased at the end of the experiment with no obvious ill effects from acetaminophen administration.
(B) This table outlines the likeliest cause of death along with a correlation with the amount of liver and renal injury. In most cases the cause of death was multi-organ failure (MOF) with evidence of hypotension, marked oedema, oliguria and ventilatory difficulties. In two animals organisms were identified in routine blood cultures. In pig 2 a cavitating lung abscess was identified although this was in addition to liver and renal injury. However in pig 9 Pseudomonas paucimobilis was identified in blood cultures with little evidence of significant renal or liver damage. +++ covered severe hepatic coagulative necrosis, ++ covered moderate hepatic coagulative necrosis and + covered mild hepatic coagulative necrosis. Similarly the scoring scale for renal injury covered the range from mild (+) to moderate (++) to severe (+++) tubular necrosis.
Pig 7 developed significant methaemoglobinaemia (>10%). Administration of Methylene blue led to circulatory collapse and death within 5 minutes. Pig 8 had moderately elevated levels of methaemoglobinaemia (>4%), and shortly before death dropped its oxygen saturations to 40%. No additional contributory cause to death was identified.