Final answer:
Positional asphyxia is a form of suffocation caused by the positioning of the body that interferes with breathing, leading to decreased oxygen and increased carbon dioxide levels in the blood.
Step-by-step explanation:
Positional asphyxia is an obstruction of breathing due to the way the body is positioned. Specifically, it refers to a situation where the positioning of the body interferes with respiration, causing the individual to not receive enough air. So among the given options, the correct definition of positional asphyxia is 3) A positioning of the body in a manner where it interferes with breathing. This can occur in various scenarios such as restraint methods or during accidents where the body is compromised in such a way that the chest or airway is obstructed, making it difficult or impossible to breathe.
Positional asphyxia can severely impact breathing, as it may reduce the surface area available for the gas exchange required for effective breathing. This leads to a decrease in oxygen levels within the bloodstream and an increase in carbon dioxide levels. When this happens, 'dead space' is created, where no ventilation and perfusion occur, which can be due to anatomical or physiological issues.
The extreme discomfort and life-threatening nature of positional asphyxia are emphasized through the mention of Peyton Farquhar in the provided excerpt, where the character experiences intense sensations, pain, and a sense of suffocation when being hanged, yet luckily falls into water due to the rope breaking. This narrative highlights how sudden obstructions and the resultant asphyxiation can be both traumatic and fatal.