Being roused out of sleep (exupnos genomenos). Becoming exupnos (rare word, only here in N.T., in lxx and Josephus). An earthquake like that would wake up any one.
Open (aneōigmenos). Perfect passive participle with double reduplication in predicate position, standing open.
Drew his sword (spasamenos tēn machairan). First aorist middle participle of spaō, to draw, as in Mar 14:47, drawing his own sword himself. Our word spasm from this old word.
Was about (ēmellen). Imperfect active of mellō with both syllabic and temporal augment and followed here by present infinitive. He was on the point of committing suicide as Brutus had done near here. Stoicism had made suicide popular as the escape from trouble like the Japanese harikari.
Had escaped (ekpepheugenai). Second perfect active infinitive of ekpheugō, old verb with perfective force of ek, to flee out, to get clean away. This infinitive and accusative of general reference is due to indirect discourse after nomizōn. Probably the prisoners were so panic stricken by the earthquake that they did not rally to the possibility of escape before the jailor awoke. He was responsible for the prisoners with his life (Act 12:19; Act 27:42).