A CRJ900 experienced pressurization fluctuations after takeoff and returned to the departure airport. Maintenance was available but no passenger service agents were present to assist passengers.

Narrative

We departed late due to a late inbound airplane. I spoke to the crew and all was good with the airplane. No MEL's and no write ups reported. The maintenance log was clean and the ship was airworthy. After a long deice process; we departed. All was normal. On climb out the left pack started to cycle on and off and the pressurization was erratic and was extremely uncomfortable. ATC handed us off to Departure Control and we checked in on departure. They gave us a climb to FL340 but we asked to stop the climb at 10000 feet because we were experiencing a pressurization issue. I looked in the Pilot Handbook and could not find a specific place for our issue because we had no chime or fault was present. I called Dispatch and Maintenance Control and advised them of the problem and that we were going to return to the departure airport. Maintenance responded telling me to refer to the Pilot Handbook. I asked them to help me find the correct area in the book because I had a lot of pressure in my head and was asking for their help in locating the specific place in the Manual. They also noted that there was no specific place because there was no Caution or Warning to follow. We returned to the departure airport with the uncomfortable pressure changes and landed uneventfully. No agents were on staff to get the gate connected to the airplane and no help was provided to us. A Pressure Controller fault due to moisture getting into the system is what the maintenance personnel seemed to suspect. I would suggest incorporating some kind of guidance to the Pilot Handbook with pressure changes that do not include a Caution or Warning. Both me and Maintenance Control couldn't find guidance based on the information. The pressure changes in the cockpit made it difficult to search in the Manual for the correct guidance. So a quick tab might be helpful. I was really disappointed when we returned to the gate and were not able to get a gate agent to the airplane. The passengers were getting restless and one wasn't feeling well and complained of stomach problems. I was unable to get any help or guidance from calling anyone because my phone did not have good service. Maintenance was there right away and after a long wait I convinced one of the maintenance guys to drive the jet bridge up to the airplane so I could deplane. After completing all the paperwork and write ups and phone calls to scheduling I walked off the plane with the rest of the crew and there was still no agent to help the passenger. There was little I could do for them and felt like I should be able to something for them. The ramp personnel were there and were able to come up to the gate and start to assist some of the passengers. They were doing the best they could but with no agent there was no way of really helping them.