NATROX Oxygen Wound Therapy Commonly Asked Questions

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1 NATROX Oxygen Wound Therapy Commonly Asked Questions SUMMARY There is a myriad of clinical data stating that wounds cannot heal without oxygen which provides the energy source for the regeneration of new tissue. However wounds must be dressed to protect and absorb wound fluids which often restricts, or even prevents the access to oxygen from the surrounding. Sufficient oxygen is normally supplied from the vascular system and in particular through the fine capillary network close to the surface of the skin. This delivery system can become inefficient due to age and certain comorbidities. Damaged wound tissue further disrupts the vascular network impeding the delivery of oxygenated blood to the wound area. The NATROX TM system delivers moist, pure oxygen directly to the wound surface providing an oxygen enriched headspace which constantly refreshes the wound and can be incorporated into most commonly used wound dressings. Best results from the NATROX TM system are found when an occlusive or semi occlusive dressing is used. 1

2 GENERAL OVERVIEW Who are Inotec AMD? Inotec AMD Ltd. is a medical device company set up in 2005 based near Cambridge in the UK. The company was founded by Mel Vinton and Professor Fray at Cambridge University to adapt and refine fuel cell technology developed in the University of Cambridge for wound healing applications, in particular the area of hard to heal chronic wounds. What is the NATROX system? The NATROX system is an innovative medical device consisting of a reusable capital device Oxygen Generator and a sterile disposable oxygen delivery system. The Oxygen Generator provides the pure humidified Oxygen, and the Oxygen Delivery System delivers this directly to the wound surface. Oxygen provides the energy source for the regeneration of new tissue together with anti-microbial properties. What does the NATROX system consist of? The NATROX system consists of a rechargeable battery powered, Oxygen Generator which is worn by the patient and is connected to a disposable Oxygen Delivery System placed directly onto the wound surface under a conventional wound dressing. Where is the hardware and disposable manufactured? The NATROX Oxygen Generator is manufactured in our Cambridgeshire facility in the UK and the disposable Oxygen Distribution System is manufactured to our unique and patented design by a specialist disposables manufacturer, again in the UK. In which countries is the NATROX system available? The NATROX system is currently available in the UK, Germany, Singapore, Middle East, Turkey, Saudi Arabia, France and Israel. We are continually adding countries and distribution partners so please check back with us directly for a current availability list. What is the regulatory status of the NATROX system in Europe? 2

3 The NATROX system has been reviewed and is approved as a Class IIa medical device in agreement with the definition of a medical device according to Art. 1, 2(a) of Medical Device Directive 93/42/EEC and MEDDEV 2.1/3 rev 3 and as such carries the CE mark. What is the regulatory status in the NATROX system in the US? The NATROX Topical Oxygen Delivery System was approved in June 2012 by the FDA for use as a Class II medical device reg: 21 CFR 878. What clinical conditions can the NATROX system treat? The NATROX system has been developed for use in the treatment of chronic and hard to heal wounds, typically non healing venous leg ulcers, diabetic foot ulcers and complex surgical wounds. How big is the wound care market that the NATROX system could address? There are various estimates of the size of market, but as an example the cost to the local healthcare system of patients with leg ulceration alone varies between 1,332 and 2,585 per year per patient in Sweden and 814 and 1,994 in the UK 12. It is estimated that the prevalence of this condition is 1.48 / 1,000 resulting in a cost of between 547 million and 1,740 million per year across Europe. 13 3

4 WHAT IS THE SCIENCE BEHIND THE NATROX SYSTEM? What is the NATROX system mode of action? A high oxygen concentration is known to have a strong antimicrobial effect in wound healing dramatically reducing the presence of microbes within the wound. This is particularly important with elderly patients where resistance to antibiotics are found. A number of studies have seen that maintaining and constantly refreshing a high concentration of humidified oxygen in the headspace above a wound supplies the energy source for the regeneration of new tissue 2 3 How does the NATROX system generate oxygen? Atmosphere air is drawn into the Oxygen Generator through small slits. Air contains moisture (Water) which is H 2 0 (Hydrogen & Oxygen). The battery powered NATROX cell electrochemically separates the Oxygen from the Hydrogen and the valuable pure Oxygen is used and the unwanted Hydrogen recombined with air to provide additional humidity. The result is ~13ml/hr pure humidified Oxygen and no release of Hydrogen. How much oxygen is generated during routine therapy? The NATROX Oxygen Generator maintains a constant flow of humidified oxygen at a rate of ~13 ml/hr Is this technique comparable to hypobaric O2 delivery methods? Hyperbaric Oxygen Therapy (HOT) is used in wound healing, but is seen as expensive and not widely available. The HOT technique involves spending a few hours in a chamber where the oxygen concentration and pressure are raised. It may require cycles of treatment to achieve beneficial results 7. In the chamber Oxygen is inhaled and absorbed into the blood, however it is unknown if this Oxygen actually reaches the wound. Patients with poor vascular activity, particularly in the fine vascular network close to the surface are most likely not to transport Oxygen to where it is needed 3. Furthermore the wound is itself damaged tissue further impeding the vascular delivery of oxygenated blood. 4

5 What is the mechanism that promotes healing with hypobaric oxygen therapy? Chronic or non-healing wounds exhibit low oxygen tensions. If the amount of wound tissue that is poorly oxygenated falls below a critical mass, the wound becomes "dormant" and the body no longer recognises the need for healing 2 3. Pre-clinical evaluations of The NATROX system used with an occlusive dressing and light compression bandaging reveal five hours after being applied, the local wound po2 had increased from 157mmHg to approximately 580mmHg an increase of x 3.6. In addition the oxygen concentration at the wound surface increased from 21% (Atmosphere) to 42%. Is the rate at which oxygen is delivered important to the ultimate patient outcome? The NATROX system is designed to provide a high flow of Oxygen at ~13ml/hr. This is required as It is not possible to achieve a perfect skin seal and indeed even occlusive dressings have an Oxygen transmission. Evaluations indicate that this level of Oxygen flow is required to maintain positive po2 levels and thereby enhance healing. What is so special about the NATROX Oxygen Delivery System? The NATROX Oxygen Delivery System is unique in that it is applied directly to the wound surface and distributes Oxygen directly to wound tissues. The design consists of a 4 layer construction where the lower (white) layer is permeable to Oxygen yet hydrophobic. Oxygen is therefore in direct contact with the wound tissue at its surface. The disposable oxygen delivery system does not become pressurised and does not absorb exudate which passes freely through the open sections for absorption and retention in a standard clinical dressing. The materials used are such that no trauma results from removal of the device when the dressing is changed. 5

6 THE NATROX SYSTEM IN CLINICAL USE Which wounds can the NATROX system be used with? The NATROX system is approved for use with the following:- Chronic wounds caused by Venous Stasis (chronic venous leg ulcers and chronic arterial leg ulcers) Diabetic foot ulcers Non healing surgical wounds including wound dehiscence Decubitus ulcers (also known as pressure ulcers or bedsores) Skin grafts Burns Skin ulcerations due to diabetes Gangrenous lesions, Amputations/infected stumps, Frostbite Is there any hard clinical data to support use of the NATROX system? There is a wealth of clinical data that supports the use of topical oxygen in difficult to heal wounds, a selection of which is referenced in the final section of this document. A multicentre, multipatient randomised study, utilising the NATROX system is currently under way and is expected to conclude in late Will the NATROX Oxygen Delivery device be absorbed into the healed wound? The design of the NATROX Oxygen Delivery System consists of a 4 layer construction where the lower (white) layer is permeable to Oxygen yet hydrophobic. Oxygen is therefore in direct contact with the wound tissue at its surface. The disposable oxygen delivery system does not become pressurised and does not absorb exudate which passes freely through the open sections for absorption and retention in a standard clinical dressing. The materials used are such that no trauma results from removal of the device when the dressing is changed. 6

7 What is the typical treatment time for a non-healing ulcerative leg wound? All patients are different and respond to any medical treatment in different ways. Initial studies indicate that typical patients should see significant improvement within 7 to 14 days and a typical treatment cycle to closure and complete healing would consist of 6 8 weeks. Can the delivery device be used with conventional compression therapy? The NATROX Oxygen Delivery System can be used with all types of conventional dressing including compression types with the exception of those dressings that incorporate petroleum based products. Occlusive or semi occlusive dressings provide best results as they retain more oxygen. Are there any contraindication for use of the NATROX system? The NATROX system is contraindicated for the following:- Ulcers due to thrombophlebitis Ulcers due to Reynaud s disease Wounds completely covered with eschar Wounds with fistulae or deep sinus tracts where the end cannot be probed Wounds covered with petroleum based dressings Inadequate perfusion to support healing Wounds with an area greater that 10cm x 10cm Ulcers resulting from infections, such as tuberculosis, syphilis, deep fungal infections Bites or 3 rd degree burns Does the NATROX system cause the wound to prematurely dry out? The NATROX system provides a constant flow of pure humidified Oxygen and maintains moist healing conditions which prevents the wound from drying out. 7

8 HOW IS THE NATROX SYSTEM USED? How long will a single charge of the battery power the NATROX unit? A fully charged battery will power the NATROX Oxygen Generator for 30 hours. A second battery is provided and this must be left on continuous charge. We suggest the change-over is made each morning to ensure continuation of the oxygen therapy. Can the battery be changed easily? Each NATROX system is supplied with two rechargeable, colour coded, batteries and a mains recharger. The battery simply slides into the NATROX Oxygen Generator and locks into place automatically activating the unit. This can be done easily by a patient or patient caregiver allowing the patient to be completely mobile. How often must the NATROX Oxygen Delivery System be changed? The disposable NATROX Oxygen Delivery System is a single use item that is placed directly on the wound surface. The disposable is changed at the same time the outer dressing is changed, which for a typical venous leg ulcer is usually two three times per week How can a Patient tell if the system is working and delivering Oxygen? A green light on the NATROX TM Oxygen Generator flashes to indicate the system is working and that oxygen is flowing to the wound. How does the patient carry the NATROX TM system? A soft cotton based holster is provided with the system which is elasticated and may be adjusted for size. Most patients will wear the NATROX TM Oxygen Generator around the leg, arm or simply place NATROX in a pocket with the oxygen delivery tube hidden inside the patient s clothing. What is included in the standard pack with the NATROX system? 8

9 Each NATROX system ships with:- 1 x NATROX Oxygen Generator (NA034) 2 x Colour coded and rechargeable battery packs (NA035-1&2) 1 x Recharger unit (NA006) 1 x NATROX Holster (NA032) 1 x Oxygen delivery extension tube 1000mm (NA042) 1 x Instructions for use (NA021) 1 x Quick Start Guide (NA059) 1 x Multi use storage case with cleansing instructions 6 x NATROX Oxygen Delivery System (NA mm) Are different NATROX Oxygen Distribution System disposables available for different wound shapes? The NATROX Oxygen Delivery System is positioned centrally on the wound. The design is such that the ODS may be trimmed (with a sterile blade or scissors) to suit small wounds or wounds with unusual geometry. How big is the NATROX Oxygen Generator system device? The NATROX Oxygen Generator is 110mm x 60mm and weighs just 100 grams (including battery), about the size of a small mobile phone. Can the patient shower whilst using the NATROX system? If the patient wishes to shower the NATROX Oxygen Generator must be disconnected from the Oxygen Delivery system and reconnected afterwards. This short interruption will not have any material effect on the therapy delivery. Does the patient need to disconnect the NATROX system when sleeping? 9

10 The NATROX Oxygen Generator is silent in use and does not need to be disconnected when sleeping. Wherever possible and to gain maximum benefit the system should remain connected and in use 24 hours per day. Can the NATROX System unit be reused? The NATROX Oxygen Generator can be reused on different patients if the detailed cleansing (wipe-down) procedure is adhered to. The Oxygen Delivery System is a single use disposable item and must not be reused. Is there any latex used in the NATROX Oxygen Delivery system? The design of the NATROX Oxygen Delivery System purposely does not contain any latex within the construction of the disposable. Have any side effects been experienced with the NATROX system? To date no adverse effects or side effects have been experienced in any patients treated with the NATROX System Can I extend the distance between The NATROX Oxygen Generator and the device in tall patients? The standard NATROX Oxygen Delivery System tube length is 1000mm. An extension tube of 1000mm (NA042) is provided for very tall patients. 10

11 REFERENCES 1. Gordillo, G. M., R. Schlanger, W. A. Wallace, V. Bergdall, R. Bartlett, and C. K. Sen Protocols for topical and systemic oxygen treatments in wound healing. Methods in enzymology 381: Sen, C Wound healing essentials: let there be oxygen. Wound Repair Regen 17(1): Cronje, F. J Oxygen therapy and wound healing--topical oxygen is not hyperbaric oxygen therapy. South African medical journal = Suid-Afrikaanse tydskrif vir geneeskunde 95: Piantadosi, C. A Topical oxygen is not hyperbaric oxygen (HBO2). Undersea Hyperb Med 30: Heng, M. C., J. Harker, G. Csathy, C. Marshall, J. Brazier, S. Sumampong, and E. Paterno Gomez Angiogenesis in necrotic ulcers treated with hyperbaric oxygen. Ostomy/wound management 46:18-28, Feldmeier, J. J., H. W. Hopf, R. A. Warriner, 3rd, C. E. Fife, L. B. Gesell, and M. Bennett UHMS position statement: topical oxygen for chronic wounds. Undersea Hyperb Med 32: Davis SC, C. A., Ricotti C, Zalesky P, Hsu LC, Creech J, Eaglstein WH, Mertz PM Topical oxygen emulsion: a novel wound therapy. Arch Dermatol 143 (10): Heng, M. C., and S. G. Kloss Endothelial cell toxicity in leg ulcers treated with topical hyperbaric oxygen. The American Journal of dermatopathology 8: Kranke, P., M. Bennett, I. Roeckl-Wiedmann, and S. Debus Hyperbaric oxygen therapy for chronic wounds. Cochrane database of systematic reviews (Online):CD Leslie, C. A., F. L. Sapico, V. J. Ginunas, and R. H. Adkins Randomized controlled trial of topical hyperbaric oxygen for treatment of diabetic foot ulcers. Diabetes care 11: Gordillo, G. M., and C. K. Sen Revisiting the essential role of oxygen in wound healing. American journal of surgery 186:

12 12. Tenvall GR Hjelmgren J: Annual costs of treatment for venous leg ulcers in Sweden and the United Kingdom. Wound Rep Reg 2005;13: Callam MJ, Ruckley CV, Harper DR, Dale JJ: Chronic ulceration of the leg: extent of the problem and provision of care. BMJ 1985; 290: