Effects of postmortem positional changes on conjunctival petechiae

Area of Science:

• Forensic Pathology
• Postmortem Changes
• Medical Autopsy

Background:

• Conjunctival petechiae are common postmortem findings.
• Their appearance and distribution can be influenced by various factors.
• Understanding these influences is crucial for accurate forensic interpretation.

Purpose of the Study:

• To investigate the association between postmortem period, physical constitution, cause of death, and cardiopulmonary resuscitation (CPR) with positional changes in conjunctival petechiae.
• To determine factors influencing the increase in petechiae over time.

Main Methods:

• Retrospective analysis of 442 forensic autopsies conducted 6 hours to 6 days postmortem.
• Assessment of palpebral conjunctival petechiae in supine and then prone positions.
• Data collected on postmortem interval, body position, cause of death, CPR status, and body mass index (BMI).

Main Results:

• Petechiae increased within 1.5 days postmortem, primarily in supine bodies.
• No significant increase in petechiae was observed in bodies found in the prone position.
• Higher rates of petechial increase occurred in supine, overweight bodies (BMI ≥ 25.0) and those who died from asphyxia or drowning.

Conclusions:

• Postmortem factors, particularly body position and cause of death, significantly influence the appearance and redistribution of conjunctival petechiae.
• Hypostatic blood redistribution is a key mechanism causing increased petechiae in palpebral conjunctivae.
• Findings aid in the forensic interpretation of postmortem changes.