Final answer:
The priority nursing diagnosis for a patient with a 9% full-thickness burn to the left leg during the acute phase is a fluid volume deficit due to the significant risk of dehydration and possible renal and circulatory failure.
Step-by-step explanation:
During the acute phase of a burn injury, the priority nursing diagnosis for a patient with 9% full-thickness burn to the left leg is a. Fluid volume deficit. This priority is due to the massive loss of fluid that can occur when skin cells are destroyed by the burn, leading to dehydration, electrolyte imbalance, and the potential for renal and circulatory failure. It is essential to manage these aspects immediately to prevent fatal complications. Treatment typically involves intravenous fluids to counteract dehydration and maintain circulation. Although pain, risk of infection, and potential for ineffective gas exchange are also concerns, addressing the fluid volume deficit is paramount in the initial stage following a burn.