If the sodium pentathol that is administered during the first stage of a lethal injection effectively wears off before the second and third drugs are delivered into the body, the offender could experience excruciating pain which is made worse since the paralytic effect of the second drug (pancuronium bromide) would seize up the vocal chords and make it impossible for the prisoner to express such excruciating pain to staff. Indeed, in 2006, the state of Missouri halted all executions for fear of causing an unacceptable risk of pain. An article in the Lancet, a highly-regarded British medical journal, showed toxicology results suggesting roughly 50% of those executed in four Southern states in the US could have been conscious before the final drug, potassium chloride, had been administered.