Adequate recovery from neuromuscular block (NMB) is imperative for the patient to have full control of pharyngeal and respiratory muscles. The train-of-4 (TOF) ratio should return to at least 0.90 to exclude potentially clinically significant postoperative residual block. Fade cannot be detected reliably with a peripheral nerve stimulator (PNS) at a TOF ratio >0.4. The time gap between loss of visual fade by using a PNS until objective TOF ratio has returned to >0.90 can be considered "the potentially unsafe period of recovery." According to our hypothesis the duration of this period would be significantly shorter with sugammadex than with neostigmine.