manner of death – Lablogatory

Ask any forensic pathologist what their professional pet peeve is and many of them will likely say “bad death certificates” (right after needing to scratch one’s nose in the middle of an autopsy). Despite the importance of death certificates to public health statistics, studies repeatedly demonstrate an unacceptably high error rate. Death certification isn’t taught in medical schools, and physicians usually learn on the fly. The media often perpetuates these errors, which is why you’ll see news headlines declaring a celebrity died of “cardiac arrest.” However, death certification is a relatively simple concept which can be easily grasped with a little instruction.

Cause of death is “that which in a continuous sequence, unbroken by an efficient intervening cause, results in death and without which death would not have occurred”. Put more simply, it is the etiologically specific disease or injury which triggers the chain of events leading to death. There’s no time limit; a cause can take years (as in breast cancer) or seconds (as in a gunshot wound). Conversely, mechanism of death describes the biochemical and biophysical processes by which the cause exerts its lethal effects. Mechanisms are non-specific and often happen in everyone who is dying (for example, hypoxia, metabolic acidosis, kidney failure). It’s easy to see why doctors list mechanisms on the death certificate—usually in a critically ill patient we’re focused on treating these mechanisms, by providing oxygen, replenishing electrolytes, and performing dialysis until kidney function has returned.

The most common example of this is “cardiac arrest.” Everyone who is dead is in cardiac arrest, by definition—what caused the cardiac arrest is what we really need to know. Putting only a mechanism on a death certificate doesn’t help families understand why their loved one died or inform them of their own potential medical risks, and it provides no useful information to public health prevention efforts.

Finally, manner of death describes the circumstances surrounding death. There are typically five options – natural, accidental, suicidal, homicidal, or undetermined. The most common manner of death error is ignoring fall-related injuries in the elderly or debilitated. A ground-level fall with femoral neck fracture can lead to death in a susceptible individual by blood loss, deconditioning, pneumonia, decubitus ulcers, or thromboembolism. Falls are not a “natural” event – they are potentially preventable, and especially in a vulnerable population may be a warning sign for neglect or abuse. For this reason, we categorize these deaths as accidental.

The nuances around death certification demonstrate one of my favorite roles as a forensic pathologist—public health informaticist. Accurate categorization of deaths allows us to track mortality data and intervene (for example, by notifying communities of a new potent fentanyl analog, or identifying trends in suicide). A death certificate of “cardiac arrest” is therefore frustratingly vague, and our patients and their families deserve a better answer. An academic autopsy program may find it worthwhile to do a quality assurance review of hospital death certificates to identify systemic errors or deficiencies. The CDC offers a free online tutorial (at https://www.cdc.gov/nchs/nvss/training.htm), which is an excellent resource for physicians or family members who want to learn more about this process.

Causes of Death	Mechanisms of Death
Atherosclerotic cardiovascular disease	Cardiac ischemia
Type II Diabetes Mellitus	Acute renal failure
Blunt force injuries	Exsanguination
Aspiration pneumonia due to cerebral infarct	Sepsis

Causes vs Mechanisms of Death: Notice that the causes are all etiologically specific diseases or injuries. The mechanisms are non-specific and lead the reader to ask “…due to what?”. For example, cardiac ischemia can be due to atherosclerosis, vasospasm, or blood loss from trauma.