AMICO CORP MICROPROCESSOR BASED DIGITAL MANIFOLD ALERT-2

Description of Event or Problem

PT WAS TRANSFERRED TO THIS FACILITY FROM TERTIARY CARE ICU FOR ONGOING CARE. PT RECEIVING 28% BLENDED OXYGEN. THIS FACILITY HAS A TWO MANIFOLD BANK SYSTEM FOR MEDICAL AIR. EACH BANK CONSISTS OF FOUR H TANKS OF MEDICAL AIR, WHEN ONE BANK IS IN USE THE OTHER SITS IN RESERVE. AS SOON AS THE BANK IN USE IS DEPLETED THE SYSTEM AUTOMATICALLY SWITCHES TO THE RESERVE BANK AND THE EMPTY TANKS ARE REPLACED. MEDICAL AIR ALARMS BEGAN SOUNDING-LEFT BANK READING EMPTY, RIGHT BANK READING LOW PRESSURE. PREVIOUS PRESSURE READINGS INDICATED SUFFICIENT QUANTITY OF MEDICAL AIR. SYSTEM ASSESSED-NO LINE LEAKS FOUND, DEPLETED BANK TANKS REPLACED. TWO DAYS LATER THE SAME INCIDENT OCCURRED-ONE BANK DEPLETED, ONE BANK LOW. AGAIN, NO LINE LEAKS FOUND. TANKS SWITCHED OUT. INVESTIGATION OF INCIDENTS CONTINUED WITH ASSESSMENT OF BLENDER IN USE. FOUND THAT THE BLENDER WAS NOT A LOW FLOW BLENDER. SET UP SWITCHED TO LOW FLOW BLENDER. WHILE THE BLENDER THAT WAS IN USE WOULD USE MORE MEDICAL AIR THAN A LOW FLOW BLENDER THIS WOULD NOT ACCOUNT FOR THE SIGNIFICANT LOSS OF MEDICAL AIR THAT WAS EXPERIENCED. ONGOING INVESTIGATION INTO THE MANIFOLD SYSTEM FOUND THAT THE PRESSURE LINE WAS GIVING A FALSE PRESSURE READING. WHEN ONE BANK DEPLETES AND THE SYSTEM AUTOMATICALLY SWITCHES OVER THE EMPTY BANK STARTED PRESSURIZING AGAIN. THE PRESSURE LINE CONTAINS A SHUTTLE VALVE THAT SHOULD SEAL OFF WHEN THE BANK SWITCHES. HOWEVER IT WAS FOUND THAT THE MEDICAL AIR WOULD BLOW BY THE SHUTTLE VALVE BACK INTO THE HEATER BAR PRESSURIZING IT AND CANCELLING THE EMPTY ALARM THUS GIVING A FALSE PRESSURE-READING. SINCE REPLACING THE SHUTTLE VALVE THERE HAVE BEEN NO FURTHER INCIDENTS WITH LOSS OF MEDICAL AIR.