Still reeling from the 15-6 loss to Ireland in Auckland, the Wallabies were intent on making a statement and crossed for 11 tries.
Centre Robert Horne, the scorer of the first try of the night, was the major injury concern after suffering a fractured cheekbone and he may yet have to be replaced in the 30-man squad.
Deans said: “The full extent we don’t know. We’ll see what the medics say first before we make that sort of decision. We’ve got an eight-day turnaround now (before the October 1 match with Russia). He’ll require some attention and we’ll wait until we make any decision. If this does rule him out it will be a bitter pill to swallow.”
Pat McCabe suffered a dislocated shoulder, Wycliff Palu had a hamstring complaint, Anthony Faingaa was stretchered off at the end and will now undergo concussion management, while Kurtley Beale’s first-half withdrawal was precautionary.
Flankers Scott Higginbotham and David Pocock (both back), wing James O’Connor (hamstring) and Digby Ioane (fractured thumb) were already absent.
The number of casualties and the severity of the injuries marred what was otherwise a comfortable win for the Wallabies.
Deans added: “We were pleased. It wasn’t perfect but there were elements in our game which we made good progress on.
“They maintained their momentum and approached the game with a slightly better mentality, with a bit more discipline in their decisions.”
The bonus point was secured before half-time with tries from Horne, Rocky Elsom, Beale and Faingaa, with number eight JJ Gagiano responding with a try for the USA.
Adam Ashley-Cooper scored three tries in seven minutes midway through the second-half, Drew Mitchell, McCabe, Faingaa and Radike Samo also scored, with Quade Cooper and Berrick Barnes kicking four and eight points, respectively.
USA head coach Eddie O’Sullivan expected Australia to flex their muscles, but was frustrated by the margin of the Wallabies’ victory.
O’Sullivan said: “I was disappointed to lose the game but there were no real shocks. Australia had something to prove tonight as well, so they didn’t let up on us at any stage. I thought the scoreline was a little bit harsh – we played some good rugby at times.
“I thought the guys battled on as long as they could.”
AUSTRALIA: Beale, Ashley-Cooper, A. Faingaa, Horne, Mitchell, Cooper, Genia, Slipper, Polota-Nau, Alexander, Simmons, Sharpe, Elsom, McCalman, Palu.
Replacements: Barnes for Beale (40), McCabe for Horne (48), Burgess for Genia (50), Moore for Polota-Nau (65), Kepu for Alexander (50), Samo for Elsom (45), Vickerman for Palu (54).
USA: Scully, Hawley, Enosa, Sifa, Swiryn, Malifa, Usasz, Pittman, Thiel, Fry, LaValla, Smith, Basauri, Danahy, Gagiano.
Replacements: Wyles for Enosa (73), Petri for Usasz (69), McClenahan for Thiel (72), Stanfill for Smith (60), Johnson for Danahy (75).
Referee: N Owens (Wales).