In which cases can systolic thigh pressures be accurately measured using a standard arm cuff?

The ability to measure systolic thigh pressures accurately using a standard arm cuff largely depends on the size of the arm and thigh. When thigh and arm diameters are similar, the arm cuff can effectively occlude the artery within the thigh, allowing for reliable blood pressure readings. This is because the pressure applied by the cuff can effectively compress the artery in a manner similar to how it would compress an artery in the arm.

In cases where the thigh diameter is significantly larger than the arm, the standard cuff may not encompass the thigh adequately, potentially leading to inaccurate readings. Similarly, using a cuff on a small or pediatric patient while trying to apply it to an adult’s thigh might also yield unreliable measurements, as the cuff size is not appropriate for the limb being tested. Thus, similar diameters between the thigh and arm facilitate effective pressure transmission, ensuring that the readings obtained are reflective of true systolic pressures.