Will it always be hard to breath after a scalenectomy?

Not likely: if no lung issues, breathing should not be affected much in the long run. No smoking Check X-ray to be sure no fluid or pneumothorax??

No. Not typically.: Unless the patient has significant pre-surgical cardiovascular and pulmonary comorbidities, a work up directed at postoperative complications such as a pneumothorax, phrenic nerve injury, or other cardiopulmonary process should be initiated.