Estimation of the postmortem interval by analyzing potassium in the vitreous humor: could repetitive sampling enhance accuracy?

The relationship between the postmortem interval and the potassium concentration in the vitreous humor has been described by different authors. A limitation of most previous studies might be that all of the vitreous humor has been extracted in 1 sample from different subjects and that the sample was therefore inhomogeneous. In 32 traumatic deaths with known postmortem intervals, small quantities of vitreous humor have been sampled repetitively in 3-hour interval. The bodies were stored at 20°C. The average concentrations of potassium in relation to the postmortem interval were 6.11 to 14.46 mmol/L. An equation that allows accurate prediction of the postmortem interval was established: postmortem interval (h) = 2.749 × [K] - 11.978.