Final answer:
The most critical assessment variable post esophagectomy requiring immediate intervention is a respiratory rate of 28, due to the potential for serious respiratory complications.
Step-by-step explanation:
The assessment variable that requires immediate intervention post esophagectomy is a respiratory rate of 28. After an esophagectomy, which is a surgical procedure to remove part or all of the esophagus, the patient's respiratory function is critical to monitor for complications such as pneumonia or respiratory failure.
While a blood pressure of 170/88 may indicate hypertension and a temperature of 38.1 could suggest an infection, both of which require medical attention, it is the elevated respiratory rate that is most concerning and could indicate an immediate respiratory issue that needs intervention. Even though pain with a score of 6/10 is also significant and should be managed, it is not as life-threatening as a compromised respiratory function. Hence, the elevated respiratory rate is the most urgent matter to address in the postoperative care of an esophagectomy patient.