ACR LGT CLBING TO FL230 ENCOUNTERED LOSS OF CABIN PRESSURE AT FL180. REQUESTED LOWER ALT BUT THE CABIN REACHED 14000 FT AND THE OXYGEN MASKS DEPLOYED. DSNDED TO 8000 FT AND CONTINUED FLT TO ORD WITH PRIORITY HANDLING. 1 PAX HAVING PROBS BREATHING AND REQUESTED MEDICS MEET THE FLT IN ORD. UNABLE TO COMMUNICATE WITH DISPATCH.

Narrative

ON TAXI OUT OF CLE; L PACK DUCT OVERHEAT AND PACK TRIP RESET VIA SOP. L PACK TRIP RETURNED. CONTACTED MAINT AND HAD L PACK DEFERRED. CLRED TO ORD VIA 1 PACK OP AT AMENDED ALT FL240. TKOF AND CLB OUT NORMAL. CABIN PRESSURIZATION WORKING OK. AS WE CLBED THROUGH APPROX FL180 I NOTICED CABIN ALT WAS EXCESSIVE. STATED THAT FACT AND ALMOST IMMEDIATELY THE CABIN ALT HORN SOUNDED. CAPT ASKED IF I COULD CTL CABIN. MY RESPONSE WAS I'M GOING TO STAND BY; MANUAL AC/DC OUTFLOW VALVE IS CLOSED; NO! WE STARTED A DSCNT TO 10000 FT. WHILE IN THE DSCNT CABIN ALT CONTINUED TO CLB AND EVENTUALLY REACHED 14000 FT AND THE MASKS DEPLOYED. ONCE LEVEL AT 10000 FT THE CABIN WAS STILL NOT COMING DOWN. FLT ATTENDANTS SAID THAT THE PAX WERE COMPLAINING OF INABILITY TO GET AIR FROM MASK. CAPT TOLD ME TO MANUALLY PULL HANDLE AND I COMPLIED. WE REQUESTED A DSCNT TO 8000 FT. 1 PAX (FEMALE) WASN'T DOING WELL. ON BOARD MEDICAL PERSONNEL ATTENDED TO HER NEEDS. THEY REQUESTED FIRST AID KIT FROM COCKPIT AND I COMPLIED. COULDN'T CONTACT DISPATCH THROUGHOUT ENTIRE FLT. THEY COULD HEAR US BUT WE COULDN'T HEAR THEM. AIRFLOW THROUGH CABIN STILL POOR. CAPT DIRECTED L PACK ON; CABIN PRESSURE NORMAL. SOMETIME DURING SCENARIO; I BELIEVE THE CAPT OR FO REQUESTED PRIORITY HANDLING FROM ATC AND THAT PARAMEDICS MEET THE ACFT AT GATE AT ORD. ATC COMPLIED WITH ALL REQUESTS. TURNED L PACK OFF ON DSCNT TO ORD. CABIN PRESSURE WORKED FINE. UNEVENTFUL LNDG; TAXI AND PARKING. MET AMBULANCE; DISPATCH AND MAINT PERSONNEL AT GATE. LESSON LEARNED: PAY PARTICULAR ATTN TO IRREGULAR OPS EQUIP DURING CLB OUT. I PROBABLY SPENT TOO MUCH TIME WATCHING ALTS; FREQ CHANGES; AND WHAT WAS GOING ON UP FRONT. SUPPLEMENTAL INFO FROM ACN 360099: THE CABIN PRESSURE WAS SOON REGAINED WITH A DIFFERENT SYS; AND WE ASKED FOR EXPEDITION TYPE HANDLING BY ATC INTO ORD ON ACCOUNT OF A PAX WITH A RESPIRATORY PROB HAVING TROUBLE BREATHING. FIRST AID OXYGEN WAS ADMINISTERED AND PARAMEDICS WERE ON HAND AT THE GATE.