Asphyxia and Asphyxial Death Overview

Asphyxia and Asphyxial Death

• Asphyxia is the interference with the mechanism or function of respiration, leading to a lack of tissue oxygenation.
• The respiration process involves oxygen from the atmosphere reaching the tissues via the respiratory system, heart, and blood.
• Causes of asphyxia include defective cellular oxygenation (poisoning), mechanical obstruction (neck compression, strangulation, or closure of respiratory orifices, or interference with respiratory movements), and other causes.
• Stages of asphyxia typically progress through dyspnea, convulsions, and ultimately apnea.
• Pathophysiology involves increasing carbon dioxide and decreasing oxygen, reduced hemoglobin (cyanosis), center paralysis in the brain, and eventually death.
• Diagnosis of asphyxia includes a history review, circumstantial evidence, complete autopsy, and toxicology tests.
• External signs of asphyxia include a swollen or cyanosed face, prominent eyeballs, swollen and potentially bitten tongue, froth around the mouth and nostrils, and cyanosed lips, ears, and fingernails.
• Internal signs of asphyxia include hypoxia, elevated pulmonary blood pressure, right-sided heart failure, pulmonary edema, froth in the air passages, and enlarged lungs with right ventricular dilation.
• Classical external signs of asphyxia include petechial hemorrhaging, froth, blue/dark hypostasis, swollen face, cyanosis, relaxed sphincters, and blood, dark fluid filling right side of the heart with petechial hemorrhage.
• Atypical drowning involves fluid not entering the lower respiratory tract, often due to laryngospasm. Drowning can be primary (occurring within minutes of submersion), or secondary (occurring half-hour to several weeks after submersion).
• Signs of immersion may include cold, pale skin (except in areas of hypostasis), granular/puckered skin, wrinkled/sodden skin, and peeling of epidermis (glove/stocking distribution).
• Highly suggestive signs of drowning include cadaveric spasm (on vegetation), fine, odorless, white or rarely blood-stained froth, and increased frothing during chest compression due to mixing of air, mucus, and water.
• Sure signs of drowning include frothy lungs, and signs of congestion with petechial hemorrhaging, sand, mud, and aquatic weeds in the respiratory bronchioles, voluminous/fluid-filled lungs, and rib impressions in the lateral surfaces.
• The Diatom test is unreliable in diagnosing drowning due to numerous false positives.
• Diagnosis (post-mortem) may assess external signs (e.g., peeling, or frothy discharge from an open wound) and internal signs (e.g., lungs containing water, froth or sand).
• Medico-legal investigations determine if death was due to drowning, the manner of drowning, and the duration of immersion.
• Suspected drowning cases analyze if death was suicidal, homicidal, or accidental, considering history, circumstantial evidence, struggle signs, and trauma.

Drowning

• Drowning is a death due to submersion in water. Complete submersion isn't always necessary.
• Types include wet drowning (hypoxic death, evident signs) and dry drowning (fluid not aspirated, laryngospasm).
• Primary drowning occurs within minutes of submersion. Secondary drowning occurs within half an hour to several weeks.
• Diagnosing drowning involves assessing immersion signs like skin changes and signs of frothing. Internal signs include filled lungs, sand, mud or aquatic weeds.
• Diatom test is unreliable.

This quiz covers the critical aspects of asphyxia, including its definition, causes, stages, and the pathophysiological effects on the body. Additionally, it addresses the methods of diagnosis and the external signs associated with asphyxia. Understand the complexities of respiratory interference and its implications for health and forensic science.