Two bodies die at the same moment. One lies in a room at 30 degrees C and the other is placed in a mortuary refrigerator at 4 degrees C. Vitreous potassium is measured from both after 12 hours. What difference is expected?

• A Identical potassium values, because the rise depends only on elapsed time
• B Lower vitreous potassium in the refrigerated body due to slowed cellular leakage ✓
• C Lower vitreous potassium in the body kept at 30 degrees C due to evaporation of the sample
• D Higher vitreous potassium in the refrigerated body due to cold-induced membrane rupture

Explanation

The rate of postmortem rise of vitreous potassium is temperature dependent: higher ambient temperature accelerates diffusion out of cells and membrane breakdown, while refrigeration slows these processes markedly. The refrigerated body will therefore show a lower potassium for the same true interval, and a formula applied without temperature correction would underestimate its postmortem interval. Cold does not rupture membranes faster; if anything it preserves them.

Reference: Knight's Forensic Pathology, 4th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.