Sarah,

Patients with implanted medical devices are often referred for hyperbaric oxygen therapy (HBOT), but the safety of exposing many of these devices to hyperbaric environments may not be known to the provider or bedside clinician. Specifically, the management of implanted neurological devices such as intrathecal drug delivery (IDD) pumps in the monoplace hyperbaric chambers. ^[1]

Implanted neurological devices, especially those containing reservoirs (e.g., IDD pumps), present unique risks. Malfunction of these devices and inaccurate medication delivery may arise from the effects of hyperbaric exposure, resulting from changes in reservoir size during compression and decompression phases of treatment, leading to rupture or warping of the device and subsequent malfunction or improper refilling and storage of medication for subsequent use. At a minimum prior to the application of HBOT, formal clearance should be obtained from the manufacturer regarding feasibility and maximum tolerable pressure for each specific device to allow for accurate assessment and minimization of possible complications such as hardware malfunctions or reservoir deformities. ^[2]

The following conversation with a manufacturer describes the case of a patient with an IDD pump, for which the specific recommendation provided by the manufacturer was provided.

“It is possible to damage the pump due to deformation of the bottom shield of the pump if it is exposed to pressures greater than 2.0 ATA for a single treatment, or at pressures less than or equal to 2 ATA with multiple treatments if the reservoir is not kept close to full; a full reservoir helps to support the bottom shield of the pump. [While the functioning of the pump is not affected by HBOT] a collapsed bottom shield may significantly reduce the pump’s drug capacity and would require pump replacement surgery. [Therefore, the suggested management of the pump would be to] keep the reservoir volume within 2 mL of the recommended [maximum] capacity of the [20 mL Medtronic SynchroMed] pump, and it should be refilled during the hyperbaric treatment period to keep it at or above these volumes”. ^[1,4]

Case report:  Hyperbaric oxygen therapy: implications for spinal cord injury patients with intrathecal baclofen infusion pumps. ^[3]

A patient with a cervical spinal cord injury receiving intrathecal baclofen for spasticity control underwent a 7-week course of hyperbaric oxygen therapy to induce healing of an ischial decubitus ulcer. After completion of this treatment and during a routine baclofen infusion pump refill, the actual pump reservoir volume exceeded computer measurements obtained with telemetry. Examination of the physiology of hyperbaric oxygen therapy in relation to infusion pump function revealed that the intraspinal pressures attained during hyperbaric oxygen therapy produced retrograde leakage of cerebrospinal fluid into the infusion pump reservoir. ^[3]

When a patient with an implanted neurological device is referred for HBOT, the device’s manufacturer must be contacted and provide documentation of clearance regarding its feasibility, safety, and best practices for management in the peri-HBOT period. We are often provided little information or guidance from the manufacturer. In those situations, the following should be considered:

IDD considerations and safety measures

·       Risk-benefit considerations based following receipt of the device manufacturer’s safety clearance per institutional policies.

·       Documentation validating the device has been pressure-tested by the manufacturer to at least the maximum intended treatment pressure.

o   If no documentation validation is or can be provided from the manufacturer the device should be identified as a NO GO item and will not be allowed in the hyperbaric chamber.

·       Deactivation of pump / device prior to introduction into the hyperbaric chamber

·       Monitoring of patients with implanted devices in the pre-, intra-, and post-HBOT periods.

·       Filling of implanted pumps prior to starting each treatment 

·       Ensure that clinical personnel evaluate the pump daily.

1.      Envoymedical.com The Evolution of Implanted Medical Devices. https://www.envoymedical.com/the-sounding-board/the-evolution-of-implanted-medical devices. Accessed 9/16/2024

2.      Schiavo S, Brenna CTA, Bhatia A, Middleton WJ, Katznelson R. Clinical Considerations for Implanted Neurological Devices in Patients Undergoing Hyperbaric Oxygen Therapy: A Case Report and Review of Manufacturer Guidelines. Int J Environ Res Public Health. 2023 May 1;20(9):5693. doi: 10.3390/ijerph20095693. PMID: 37174212; PMCID: PMC10177826.

3.      Akman MN, Loubser PG, Fife CE, Donovan WH. Hyperbaric oxygen therapy: implications for spinal cord injury patients with intrathecal baclofen infusion pumps. Case report. Paraplegia. 1994 Apr;32(4):281-4. doi: 10.1038/sc.1994.49. PMID: 8022638.

4.      Sales Representative. ((Medtronic, Minneapolis, MN, USA)). Personal communication. 2021

I hope this helps. Have a great day!

Jeff