Circulation 118,032 • Volume 30, No. 2 • October 2015   Issue PDF

Manufacturer Responds Regarding Defective Gas Sampling Line

CDR Mark J. Lenart MD; LCDR Shane E. Lawson CRNA, MS; Kathleen Zimmermann,Sr. Director, Quality Operations,Pall Medical

We provide anesthesia services for a small outpatient surgery center. During the ASA/FDA recommended pre-anesthetic checkout, 3 anesthesia machines failed the “breathing system pressure leak testing.” Standard troubleshooting methods were employed, including replacing anesthesia circuits, replacing water traps, and checking all connections and fittings without resolution. Further troubleshooting identified the failure in the gas sampling line connector. The gas sampling lines were not properly fused with the connector (see Figure 1). This defect was noted on multiple circuits, explaining why replacing the circuit did not correct the leak. The failure was immediately addressed by replacing the gas sampling lines. The quality assurance department of the circuit manufacturer was contacted to initiate corrective actions in the manufacturing process (see below).

CDR Mark J. Lenart MD LCDR Shane E. Lawson CRNA, MS Department of Anesthesiology, Naval Medical Center Portsmouth, Portsmouth VA

Reply from Pall Medical

Dear Dr. Segura-Vasi,

I would like to provide you an update regarding Pall Medical’s investigation into sporadic reports of a leak with the Pall Ultipor™ Anesthesia Breathing Circuit System (Adult 72” Circuit) product code VM72COAX. The referenced leaks have been isolated to the gas sampling line where the tubing is bonded to the connector and have been detected during the pre-use ASA/FDA leak testing.

Investigation Findings:


Figure 1. Defective Connector.

Returned samples were thoroughly tested and the report of a leak was confirmed. A root cause analysis has been conducted and the following potential causes were identified:

  1. An insufficient solvent application occurred during the manual tubing to connector assembly process. Insufficient solvent could permit dry spots to occur resulting in the reported leaks.
  2. The leak test equipment was found to be functioning properly however; it is believed that the operator failed to identify and reject the defective product.

Actions Implemented

To reduce the potential for recurrence, the manufacturing facility implemented the following actions:

  • The bonding process has been improved to include the use of an automatic solvent level control on the solvent dispenser for a more consistent application.
  • The solvent bonding instruction was revised to include the rotation of the tubing by >45 degrees for a more consistent application of the solvent on the tubing surface.
  • An indicator light, “Pass” (Green Light) “Fail” (Red Light), was implemented on the test equipment as a visual aid for improved leak detection.
  • Test equipment was modified to have an audible sound if a leak is present in order to enhance the operator’s ability to detect a failed unit.
  • Associated work instructions were updated and training sessions held with manufacturing personnel.

Pall Medical continues to monitor the effectiveness of the above actions and will implement additional improvements if deemed necessary.

We appreciate your interest in this matter and hope the information above meets your needs. If you should have any questions or should require additional assistance, please do not hesitate to contact the Pall Medical Customer Care Hotline at 1-800-645-6578.

Sincerely, Kathleen Zimmermann Sr. Director Quality Operations Pall Medical

The APSF Committee on Technology The information provided is for safety-related educational purposes only, and does not constitute medical or legal advice. Individual or group responses are only commentary, provided for purposes of education or discussion, and are neither statements of advice nor the opinions of APSF. It is not the intention of APSF to provide specific medical or legal advice or to endorse any specific views or recommendations in response to the inquiries posted. In no event shall APSF be responsible or liable, directly or indirectly, for any damage or loss caused or alleged to be caused by or in connection with the reliance on any such information.