Successful hyperbaric oxygen treatment of a patient with a HeartMate III left ventricular assist device.

A 53-year-old woman with a HeartMate III left ventricular assist device (LVAD) was successfully treated under hyperbaric conditions for haemorrhagic cystitis. The HeartMate III LVAD inserted in this patient had not previously been tested or certified for use under hyperbaric conditions. To our knowledge this is the first report of the HeartMate III LVAD being used to support a patient undergoing hyperbaric treatment. The overview detailed here of the safety and technical aspects of managing this patient for hyperbaric treatment was possible due to the collaboration of a multi-disciplinary team. We believe that our experience has demonstrated a pathway to safe hyperbaric treatment of patients dependent upon a HeartMate III LVAD.

A pleural vacuum relief device for pleural drain unit use in the hyperbaric environment.

INTRODUCTION: When a standard water-seal pleural drain unit (PDU) is used under hyperbaric conditions there are scenarios where excessive negative intrapleural pressure (IPP) and/or fluid reflux can be induced, risking significant morbidity. We developed and tested a pleural vacuum relief (PVR) device which automatically manages these risks, whilst allowing more rapid hyperbaric pressure change rates. METHODS: The custom-made PVR device consists of a one-way pressure relief valve connected in line with a sterile micro filter selected for its specific flow capacity. The PVR device is designed for connection to the patient side sampling port of a PDU system, allowing inflow of ambient air whenever negative pressure is present, creating a small, controlled air leak which prevents excessive negative pressure. The hyperbaric performance of a Pleur-Evac A-6000 intercostal drain was assessed with and without this added device by measuring simulated IPP with an electronic pressure monitor connected at the patient end of the PDU. IPP readings were taken at 10, 15, 20 and 30 cmH2O of suction (set on the drain unit) at compression rates of 10, 30, 60, 80, 90 and 180 kPa·min⁻¹ to a pressure of 280 kPa. RESULTS: At any compression rate of > 10 kPa·min⁻¹, the negative IPP generated by the Pleur-Evac A-6000 alone was excessive and resulted in back flow through the PDU water seal. By adding the PVR device, the generated negative IPP remains within a clinically acceptable range, allowing compression rates of at least 30 kPa·min⁻¹ with suction settings up to -20 cmH2O during all phases of hyperbaric treatment. CONCLUSIONS: The PDU PVR device we have developed works well, minimising attendant workload and automatically avoiding the excessive negative IPPs that can otherwise occur. This device should only be used with suction.

Evaluation of the Carefusion Alaris PC infusion pump for hyperbaric oxygen therapy conditions: Technical report.

We present a standardized test methodology and results for our evaluation of the Carefusion Alaris PC infusion pump, comprising the model 8015 PC Unit and the model 8100 Large Volume Pump (LVP) module. The evaluation consisted of basic suitability testing, internal component inspection, surface temperature measurement of selected internal components, and critical performance testing (infusion rate accuracy and occlusion alarm pressure) during conditions of typical hyperbaric oxygen (HBO2) treatment in our facility's class A multiplace chamber. We have found that the pumps pose no enhanced risk as an ignition source, and that the pumps operate within manufacturer's specifications for flow rate and occlusion alarms at all stages of HBO2 treatments, up to 4.0 ATA and pressurization and depressurization rates up to 180 kPa/minute. The pumps do not require purging with air or nitrogen and can be used unmodified, subject to the following conditions: pumps are undamaged, clean, fully charged, and absent from alcohol cleaning residue; pumps are powered from the internal NiMH battery only; maximum pressure exposure 4.0 ATA; maximum pressurization and depressurization rate of 180 kPa/minute; LVP modules locked in place with retaining screws.

Test results for the evaluation of a glucometer for use under hyperbaric conditions: Technical report.

This study aimed to evaluate a recently developed equipment test method by assessing the safe and accurate functioning of the Abbott Optium FreeStyle H portable blood glucose monitor for use in the Alfred Hospital's hyperbaric chamber. The results of this study indicate that the test method can be used successfully to evaluate instruments and/or devices for use in the hyperbaric environment. The evaluation initially found that this particular glucose monitor contained a lithium battery which can be hazardous when used in the hyperbaric environment. However, upon further inspection it was determined the battery posed minimal risk for fire and explosion due to its small capacity and design application. The results indicate that the Abbott Optium FreeStyle H blood glucose monitor operated normally when used in the hyperbaric chamber. This glucometer was found to perform within the calibration specification requirements for accuracy at all stages of a typical hyperbaric treatment and as such the Abbott Optium FreeStyle H blood glucose monitor was deemed safe for use in the hyperbaric chamber at the Alfred Hospital.

Performance of the BBraun perfusor space syringe driver under hyperbaric conditions.

BACKGROUND: The BBraun Perfusor Space™ syringe driver is already in use by ambulance services and retrieval teams but has not previously been assessed for hyperbaric chamber use. METHODS: Pump flow accuracy was tested at rates between 1 and 40 ml· h⁻¹ using three different brands of 50 ml syringe. Function of the occlusion alarms was assessed using the same syringes. The hyperbaric profile involved pressurisation to 284 kPa at 30 kPa· min⁻¹, 30 min at 284 kPa and decompression at 30 kPa· min⁻¹. Output was recorded from differences in weight of collection containers. A single device was tested. RESULTS: Performance was highly dependent on the syringe type used, with two of the three 50 ml syringes used demonstrating 'stiction' at both low and high occlusion pressure alarm settings, most marked during pressurisation. On decompression from 284 kPa all syringes alarmed at significantly lower pressures. Because of the stiction problems only the flow measurements for the BBrown Omni¬ x 50 ml syringes are reported. At a pressure of 284 kPa, the difference between programmed and delivered rates was within the manufacturer's specification of 10%: at 40 ml· h⁻¹ (median variation 1.25%, IQR 0.5-1.7%), 10 ml· h⁻¹ (8.6%, IQR 8-9.2%), 5 ml· h⁻¹ (-8.8%, IQR - 1.6-8.8%) and 1 ml· h⁻¹ (-4%, IQR 4-12%). Pressurisation was associated with significantly lower flow rates whilst decompression was associated with significantly increased rates. Limited testing at 405 kPa was also within the manufacturer's specifications. CONCLUSION: A BBraun Infusor Space syringe driver performed within acceptable performance criteria but is highly dependent on syringe type and flow rates. The potential for the device to under deliver on pressurisation and over deliver on depressurisation, however, suggests vigilance and appropriate rate adjustments may be necessary during these phases.