Forensic Medicine: Death

As a doctor you will inevitably have to deal with death and dying. Its hard and emotionally testing but you have to know what to do. There is a chance that you will be called to certify a death and you may have to make a decision about whether an autopsy is needed. I hope to cover everything about death in this post. disclaimer: I attend an international medical school so the laws may be different in different countries, most of the laws described here fit English and Italian law, I have tried to be as general as possible so to cover most countries. 

First of all how does one certify a death and how can you be sure that someone is in fact dead?
The respiratory, cardiovascular and neurological systems are regarded to be essential for life. therefore most assessments of life will address these systems. 
When the authorities come to you for a death certification, what they need is a proof of death, they don't need you to determine the cause of death. Usually there will be an ECG at hand and you will certify death by verified lack of cardiac activity (20min continuous ECG). If there is no ECG, then you will have to determine death based on post-mortal phenoma and other physical signs. 
There is anyway a mandatory 24hour period of observation of the body (usually in the morgue) just to make sure the body is in fact dead. the observation is mandatory except for putrified bodies (rotting bodies) or with decapitated bodies. 

In the UK you can certify death by fulfiling the following criteria:

• No palpable pulses.
• No heart sounds on auscultation (or asystole on ECG).
• No reaction to painful stimuli
• No breath sounds on auscultation and no observed respiratory effort. 
• Pupils dilated and not reactive to light.

Its important to assess without any unnecessary delay and ensure accurate documentation in the patient notes with your assessment and the time of death. 

In order to bury a body the national mortuary regulation requires a complete MCCD (medical certificate of cause of death form) with a cause of death. This makes determining the cause of death more important than certifying death as the body cannot be buried without it. The form is used for statistical purposes. The form has three spaces for the cause of death; a final cause of death, an immediate cause of death and an initial cause of death. Its not easy to state what the actual causes and potential chain reaction to death is. Frequently the final cause of death is cardiac arrest or respiratory arrest, but what caused it? 
A couple of examples:
Stab wound - massive hemorrhage - cardiac arrest
Abdominal aortic aneurysm - anuerysm rupture - cardiac arrest
(dont use an abbreviations when filling out this form).

There is an area whee you state comorbidities that may have contributed to the death and a separate area to fill in regarding traumatic deaths (was the death a suicide, homicide or accident). after filing the in the form you simply sign it and state your registration number. 
The aim of the MCCD is to monitor deaths in the country, and still quite often we don't know what caused some deaths. For example a patient arrives in ER and dies shortly after or a patient with a history of heart disease dies at the GP practice. You have to pay attention when filling in this form, you should fill in the form with "scientific knowledge and good conscious" as the Italians put it. 
a physician should fill in this form only is he or she feels relatively confident about the cause of death (you can never be 100% sure). Any cause of death can be put on the form, if the cause of death is not filled in or the form not submitted then an autopsy will be requested by the national health system (NHS) (hospitals themselves can also request an autopsy). Never feel forced to fill in the form. With autopsies the system feels safer. 

If a normal national health autopsy is conducted and suspicious lesions are found for example a neck hematoma, then the autopsy is automatically stopped and referred over to the judicial system. Before a judicial autopsy no one can touch the body (no tampering). There is sometimes are threats to pathologists dealing with a body from gang members.

Its important to note that the families have no say in what happens to the dead body, dead bodies do not belong to the family. Although ethical and morally its good to inform the family about what is happening to the body of course.

Just to highlight, if you are not sure about the cause of death do not sign the form!

There are two laws that protect the dead a first law protecting the dead against maiming and a second law basically saying that family's have no say in what happens to the body. Many religions don’t want the body tampered with and this clashes with the law, the law needs to be respected.

Judicially speaking, a dead body is not a person and therefore loses the rights of a person. There are many controversies and questions related to privacy, however the answer usually swings to the fact that dead bodies have no rights like living people. 

Every year in Milan 2-3 bodies and in Italy over 1000 unidentified bodies are discovered and buried without a name. Some places tried to provide a facility where you could put a picture online of the cadaver in hope of an identity such as the  UK missing persons bureau. Although these can clash with some authorities over privacy issues. 

When a person dies the family will need more support than ever. 60-70% complaints to doctors regarding life-death issues are due to the family not  being given enough attention and feeling like they were not appropriately listened to. After a death, sit down and talk to the relatives. There usually is a bereavement team at the hospital you can contact, who will liaise with the family. 

Pathological phenoma following death

These phenoma can be used to identify a person, the time of death and sometimes even the cause.

After immediate death there is an early post mortum period, then after the decomposition period and finally after that taphonomic factors.

The early post mortum period is what forensic pathologists and doctors certifying death will mostly be dealing with. You may even get a call to certify death when the body is already full of worms, but a doctor is still needed to certify death even in this case.

Three phenoma are seen during the early postmortum period

• Algor mortis (cooling)
• Rigor mortis (rigidity)
• Livor mortis (a hydrostatic phenoma)

Algor mortis (not Al Gore mortis)

Algor mortis starts as soon as the vital activity of the body stops. We cannot see with the naked eye the metabolic changes on a cellular level but you can feel and measure the temperature. The body will start at around 37 degrees on death and will slowly reach the temperature of the surrounding environment. Never trust if a body just feels cold, always use an objective measured reading.  Depending on the reference textbook you use, Below 34 degrees is considered not compatible with life. Use an internal measure of temperature, for example the mouth or rectum (or even tympanic temperature, see below). The time from death is linked to the temperature but depends on many variables.

You may be asked if the death was recent or not. You can try and correlate the environment with the temperature you record, there are in fact many equations that can be used to estimate the time of death but even the best of these will give you a result with plus or minus 2 hours minimum from time of death (plus or minus 4 hours is probably a better considerate). Many of these equations insist on rectal temperature and hence the error because the rectal temperature ha a large plateau in which it does not alter, it takes a while to change.

Ear temperature is much more representative of cooling, the speed and for how long for. This is because the variables change less in the head (no difference in body fat surrounding for example). Often many doctors with take the temperature with the back of the hand, never do that! use a thermometer!

Rigor mortis

The physiology of rigor mortis is well understood. The lack of ATP production after death causes ATP to eventually run out and the actin-myosin contractile unit of muscles to be locked in place (the myosin heads cannot detach without ATP). The onset takes a little while, while there is still ATP in the muscle. Eventually the muscle becomes locked in place and it is a very strong contraction. I read about pathologists forcing the joints (breaking the joints) in order to get arms or limbs straight.  It tends to start at the head and extend down to the feet and it devolves in the same way from head to feet. It can even take a few days to resolve in some cases.

Livor mortis

Livor mortis sets in after a few hours. It is quite simply the pooling blood in the body due to gravity. Slowly as time goes by, the endothelium collapses and the blood infiltrates the tissues. The pooling of blood will cause discoloration of the tissues, and you will see pink purple areas on the skin. If the cadaver was on it's back, the lower part of the body will be pink and the compressed areas of contact will be white. A handy test is if you compress the pink area with your finger, if the death was less than 6-10 hours ago then the blood will move away on finger compression (become white). If you were to roll the body  less than 6-10 hours after death then the pink areas would move, if the death was greater than 6-10 hours ago then the pink areas will stay pink .

Time frames

First considering algor mortis there are four stages after death with related time periods

Algor mortis:

0-3hours Plateau phase (no change in temp)

6-8hours Fast cooling stage (most accurate for determining time of death)

10-12hours Final plateau phase

11-30hours End of cooling.

Rigor mortis depending on the textbook tends to begin at around the 3hours-12hours mark, with the highest intensity of contractions between 12 and 48hours, resolution is around the 72hours mark.

Livor mortis has an onset around the 2hour mark with the highest intensity of discoloration at the 12hour mark, at 10hours-12hours the blood can still migrate at the 48-72hour mark it becomes fixed.

(Note that compression areas will be white and hanging limbs will be pink, consider gravity).

Transformative processes

When you are asked to certify a dead body you have to know what to expect. If the death happened a long time ago you will see the so called transformative processes. When these processes kick in you need to be aware that its impossible to determine the time of death. The onset and time frames are incredibly variable and depends on many variables and environmental factors.

Transformative processs can be either destructive or conservative.

Destructive:

Autolysis

Putrefaction

Maceration

Conservative:

Mummification

Adipocere

Corification

Mummification is caused by the loss of water from the soft tissues, and can preserve the tissues for a very long time. In theory if you rehydrate the tissue you will see the same tissue as before. True mummification is very rare. 

Adipocere usually occurs when the body is left in water, the tissue becomes a weird creamy soft texture and then sets after a while to an incredibly rock hard shell. 

Damp bodies may not putrefy and can undergo so called wet mummification where all the cells are lost and just the fibrous collagen based skeleton of the tissues remains, it appears very similar to mummification with brown appearance.

Criminal cases look at the exterior limits of these processes. It can be hard to not lose body parts when these processes kick in when you are collecting the body. 

Putrefaction is the main transformative process for dead bodies at our latitude. Putrefaction is decomposition of the body and causes a marble like green discoloration to the body (green due to hemoglobin catabolism), usually the processes start in the lower right quadrant of the body (this is because the cecum contains the highest concentration of bacteria in the GI tract). There is also bloating due to the gases produced. Eventually everything breaks down and turns to water. When you come across a putrefied decomposed body this is one of the rare scenarios where on the MCCD you can write the cause of death as indeterminate.

Many factors affect these processes: temperature, wind, season, soil pH, moisture content of soil, morphological characteristics, patient age, cause of death, laceration or discontinuations of the skin.