Graham Dorrans' first-half goal condemned Rangers to a 1-0 defeat at West Brom on Saturday, which meant they have failed to win any of their last 11 Premier League away matches - their last success on the road coming against Stoke on November 19.
While they remain outside of the bottom three, they lead 18th-placed Bolton by just two points having played two more matches than Owen Coyle's side.
They have won their last three home games only to have lost their previous four on their travels and, with a tough run-in to come - they must face Tottenham, Chelsea, Stoke and Manchester City - their top-flight status now hangs in the balance.
Hughes said: "We can't just think our home form will be enough. We have talked about picking up our away form and this was an opportunity for us.
"The first half we didn't put enough pressure on West Brom, we were a little bit off the pace - I'm not sure if that was down to our midweek efforts in beating Swansea.
"We allowed them too much time and space to pick passes around our box. We were also slow getting out to Dorrans for the goal, although it was a great strike.
"All in all, it was a frustrating day because we were great on Wednesday but unfortunately we didn't hit that level here. What we produced wasn't good enough and we didn't push them hard enough.
"When you are away from home you always need to do the fundamentals well and disappoint the crowd and the team itself but, unfortunately we gave them too much encouragement.
"They seemed to be quite enjoying themselves. It is a marked contrast to how we played in midweek, that's the frustrating thing. We can't be consistent over a period. We now have a week of hard work to put in to get ourselves right for next weekend."
The game's only goal arrived courtesy of Scotland international Dorrans' unstoppable 22nd-minute strike from 25 yards, having been teed up by Peter Odemwingie.
Head coach Roy Hodgson said: "It was a marvellous strike and he deserves a lot of credit after such a lot of time out. He has had a season which has been interspersed with injuries, every time he has looked like getting back in the team he has had to drop out again. We are delighted with him, he settled the game for us.
"After looking pretty good for victory in the first half - we played some very good football - we lost our way a bit in the second half. A lot of credit to QPR, they asked a lot of questions. But we showed a lot of grit keeping them at bay."
It earned the Baggies only their second win in seven matches as they moved onto 42 points to guarantee a third successive Premier League campaign for the first time in their history.
"We have got over the line with some margin of comfort. I am delighted with the players. It was a game in which we could have been forgiven for not making that lung-bursting final effort, but the players did," he said.
"We would be sensible to be worried about next year as well. There's work to do, it won't be easy to find the quality we need as we already have a good squad."
Source: AFP
Source: AFP