Which assessment can determine the effectiveness of breathing in a casualty?

The assessment that can determine the effectiveness of breathing in a casualty is chest rise and breath sounds. Observing chest rise is a direct indicator of whether air is entering the lungs effectively during inhalation. If the chest rises adequately, it suggests that the lungs are expanding properly to facilitate gas exchange.

Additionally, auscultation of breath sounds provides vital information about the airways and lung function. Normal breath sounds indicate that air is moving through the airways and into the lungs without obstruction. Abnormal sounds, such as wheezing, stridor, or absence of breath sounds in one lung area, may indicate issues such as bronchospasm, obstruction, or pneumothorax, all of which can severely impact the casualty's ability to breathe effectively.

While pulse oximetry can also be useful in assessing the oxygen saturation of the blood, it does not provide a complete picture of the breathing mechanism itself. Skin mottling and temperature of extremities may indicate shock or circulatory issues but do not directly reflect the effectiveness of breathing. Therefore, evaluating chest rise along with breath sounds is the most comprehensive assessment of breathing effectiveness in a casualty.