Autopsy: external exam

1. central lines

2. endotracheal tubes

3. feeding tubes

4. urinary bladder catheters

5. electrical medical devices (?)

Identify medical device types that cannot be removed in the external exam, according to lecture and Connolly

1. Need to verify location because misplaced medical devices could have long lasting complications on the patient and potentially lead to death

   1. Central lines - should be placed in a vein

   2. Endotracheal tube - should be in the trachea and not in the esophagus

   3. Feeding tubes - gastric should be in the stomach and not in other parts of the abdomen; nostril should be in the esophagus and stomach, not in the airway

   4. Urinary catheters - should be placed directly into the bladder; can cause hemorrhagic mucosa

Recognize the importance of maintaining the anatomic location of specific medical devices at autopsy, as discussed in lecture

livor mortis

gravitational pooling of blood; appears after irreversible circulatory arrest; fills paths of least resistance - parts of body experiencing external pressure remain pale

rigor mortis

stiffening of muscles (without shortening) due to depletion of ATP with the formation of stable myosin-actin complexes due to calcium presence, preventing muscles from relaxing

algor mortis

cooling of the body temperature after death until it reaches ambient temperature

1. can accelerate the appearance and disappearance of rigor mortis

   1. depletion of ATP so ceases after death, increased body temperature, muscle fatigue

   2. elevation of initial body temp can also impact algor mortis

Discuss how an extreme increase in physical activity prior to death can have a significant impact on rigor mortis as presented in lecture

autolysis

aseptic breakdown of tissue due to the release of intracellular enzymes

putrefaction

breakdown of tissue due to bacteria, primarily from the GI tract

greenish discoloration of skin on lower abdomen (usually RLQ); occurs 24 hours after death

what is the first sign of decomposition?

1. First sign of decomposition = greenish discoloration of skin on lower abdomen (usually RLQ); occurs 24 hours after death

2. 24-36 hours = swelling and green discoloration of face and neck with protrusion of eyes and tongue; emergence of “purge fluid”

3. 36-48 hours = marbling (green-brown) discoloration along blood vessels due to hemolysis

4. 2-3 days = bloating, skin slippage, blistering

5. 3 months = mummification in warm, dry environments; skin becomes leathery, dark, shrunken

6. 6 months = adipocere; body’s fat becomes hydrogenized by bacterial enzymes resulting in white-brown waxy skin (warm, humid environments)

7. Skeletonization = weeks to months to years

Describe the stages of decomposition that exist in the postmortem state as presented in lecture

1. begins 0.5-2 hours post mortem

2. 2-8 hours will blanch

3. becomes set ~8-12 hours

describe how to use livor mortis to calculate time of death

1. assume ambient temperature = 23°C, normal body temperature = 37°

2. initial phase consists of plateau of 2 hours where temp remains stagnant

3. body cools at a rate of ~1° C per hour (intermediate phase)

4. once at ambient temp, will stop decreasing (~16 hours after death for normal conditions)

describe how to use algor mortis to calculate time of death

1. begins slowly at time of death and becomes apparent within 2 hours

2. 12 hours to develop

3. 12-24 hours full rigor

4. 12 hours to disappear

describe how to use rigor mortis to calculate time of death

1. external exam is more critical for forensic autopsies compared to medical

2. clues to what you may look for and insight into possible findings on the internal exam

   1. tumors/masses, cloudy eyes → glaucoma, facial hair in females → ovarian tumor

   2. sexual trauma → medicolegal case

   3. assessment of visible injuries

3. evidence: toxicology, natural, environmental, traumatic

4. documentation

5. identification (tattoos, scars, birthmarks, fingerprints)

6. time of death (algor, rigor, livor mortis, decomposition)

Recognize the importance of the external examination in the PAD, as discussed in lecture