Under what circumstance would you loosen a pressure dressing applied to a casualty's arm?

Loosening a pressure dressing applied to a casualty's arm is critical when there is no pulse in the limb below the bandage. This situation indicates that the pressure dressing may be too tight, potentially compromising blood flow and leading to further tissue damage or necrosis. The absence of a pulse is a clear sign that the blood circulation to the limb is being obstructed, underscoring the urgency of alleviating any constrictive pressure to restore vascular function.

Recognizing the scenarios when to loosen a dressing is crucial in a combat life-saving setting, as it directly impacts the casualty's survival and recovery. This response is essential not only for preserving limb health but also for ensuring adequate oxygenation of tissues.

In contrast, other circumstances such as when bleeding has stopped, when a wound becomes infected, or when the bandage becomes stained with blood do not inherently necessitate loosening the dressing. Instead, managing bleeding effectively, addressing infection properly, or replacing a saturated bandage might be more appropriate actions in those instances.