Final answer:
The nurse would review a culture and sensitivity test to determine if the pressure ulcer on a patient's left heel is infected. Other tests like white blood cell count and complete blood count indicate infection but are not specific to the ulcer.
Step-by-step explanation:
To determine if the pressure ulcer on a patient's left heel is infected, the nurse would review a culture and sensitivity test. This test involves taking a tissue or fluid sample from the wound and growing bacteria from the sample in a laboratory to see if an infection is present and to determine which antibiotics the bacteria are sensitive to, ensuring appropriate treatment. While a white blood cell count and complete blood count could indicate infection due to an increase in the number of white cells, they are not specific to the ulcer itself and do not identify the causative agent or the antibiotic susceptibility of the bacteria. An X-ray of the left foot could be used to check for osteomyelitis, which is an infection of the bone, but it would not determine if the soft tissue ulcer is infected specifically.