Which one of the following signs is not likely to be seen when an adult casualty is choking?

When considering the signs associated with an adult who is choking, the presence of red lips is not typically observed. Choking usually results in a lack of sufficient airflow, which can lead to various physiological responses in the body. Specifically, during choking, individuals may demonstrate signs such as gasping actions as they attempt to draw in air, an inability to speak due to the obstruction, and labored breathing as their body struggles to get oxygen.

Red lips are not a common indicator of choking; rather, they may suggest adequate oxygenation or circulation, which is contrary to the effects of choking. The physiological response to a choking incident typically involves the body's efforts to compensate for the lack of oxygen, leading to signs such as pallor or cyanosis around the lips, rather than redness. This distinction highlights why red lips would not align with the expected signs observed in an adult casualty experiencing choking.