Demand valve oxygen therapy

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Demand Valve Oxygen Therapy (DVOT) is a way of delivering high flow oxygen therapy using a device that only delivers oxygen when the patient breathes in and shuts off when they breathe out. DVOT is commonly used to treat conditions such as cluster headache, which affects up to four in 1000 people (0.4%),[1][2][3] and is a recommended first aid procedure for several diving disorders.[4][5] It is also a recommended prophylactic for decompression sickness in the event of minor omitted decompression without symptoms.[5]

Medical uses[edit]

Cluster headache[edit]

High flow oxygen therapy, delivered at a rate of between 7 and 15 litres per minute, has been recognized as an effective treatment for cluster headache since 1981.[6] Since then, several double-blind, randomized, placebo-controlled, crossover trials have provided further clinical evidence for its efficacy.[7][8]

When inhaled at 100% at the outset of a cluster headache attack, high flow oxygen therapy has been proven to abort episodes in up to 78% of patients.[7] Inhaling 100% oxygen is recommended by the European Federation of Neurological Societies as the first choice for the treatment of cluster headache attacks.[9][8] The British Thoracic Society and National Institute of Health and Care Excellence, among other organisations, endorse the therapy.[10][11]

Diving disorders[edit]

  • Decompresiion sickness, as first aid during transport to recompression facility.[12]
  • Omitted decompression, with or without symptoms of DCS. As prophylaxis where recompression is not practicable.[12]

Equipment[edit]

A portable administration set will comprise a portable high-pressure oxygen cylinder containing sufficient gas for the expected treatment, with an oxygen service cylinder valve, an oxygen compatible first stage regulator with pressure gauge, intermediate pressure hose, and demand valve with mouthpiece.

Equipment for cluster headache treatment[edit]

Demand valves [1] have been proven to be particularly effective at delivering high flow oxygen therapy.[13] Unlike conventional breathing systems, oxygen demand valves only deliver gas when the patient inhales and shut off the flow when they exhale. Exhaled gas is directed to the atmosphere through side vents. This means that almost 100 percent of the oxygen is inhaled, while the amount of exhaled carbon dioxide that the patient rebreathes is minimized.

Demand valve function
Demand valve exhalation
Demand valve inhalation

Compared to other mask types, demand valves have been better at achieving pain relief at 15 minutes in the first cluster headache attack.[14]

Equipment for diving first aid[edit]

For diving first aid an oxygen compatible diving regulator may be used if a special purpose oxygen treatment demand valve is not available. Technical divers routinely use such equipment for in-water decompression.

When used in diving recompression chambers and multi-place medical hyperbaric chambers, a built-in breathing system venting to the exterior is generally used to avoid buildup of oxygen partial pressure in the chamber to dangerous levels which would otherwise require more frequent venting.

Clinical studies[edit]

Cluster headache[edit]

Numerous clinical studies have proven the effectiveness of high flow oxygen therapy and demand valve therapy for treating initial and subsequent cluster headache attacks:

Response of cluster headache attacks to oxygen inhalation (Published 1981) - Director Lee Kudrow M.D.

The original landmark study into the effectiveness of high flow oxygen therapy in relieving the symptoms experienced by cluster headache sufferers. Oxygen was administered to 52 patients at 100% purity at a rate of 7 litres per minute through a facial mask for 15 minutes at the onset of attacks. The study concluded that oxygen therapy was effective in relieving symptoms.

High oxygen flow rates for cluster headache (Published 2004) - Todd D. Rozen

This study explored the effect of administering higher flow rates of oxygen to cluster headache patients who had not responded to standard oxygen therapy regimens. Higher flow rates of up to 15 litres per minute were found to be effective in relieving symptoms

High-Flow Oxygen for Treatment of Cluster Headache: A Randomized Trial (Published 2009) - Anna S. Cohen; Brian Burns; Peter J. Goadsby

This study compared the effects of high flow oxygen therapy on 57 patients with episodic cluster headache and 19 with chronic cluster headache. It found that those patients who inhaled oxygen were more likely to experience no pain after 15 minutes compared to patients who took a placebo.

Oxygen therapy for cluster headache. A mask comparison trial. A single-blinded, placebo-controlled, crossover study (Published 2016) - Anja S Petersen, Mads CJ Barloese, Nunu LT Lund and Rigmor H Jensen

Three different types of mask were examined in this study to determine the differences in their effect on the treatment of cluster headache. Among the 57 patients who took part, demand valve oxygen was found to be significantly better at achieving pain relief at 15 minutes in the first attack. The study also found that the Ultraflow oxygen demand systems reduced the duration of attacks.

Procedure[edit]

Contraindications[edit]

Hazards and precautions[edit]

High oxygen concentrations in the surroundings constitute a fire hazard. Oxygen therapy should be accompanied by good ventilation and avoidance of ignition sources, and where reasonably practicable, removal of combustible materials. Oxygen firebreaks are a requirement in some countries for patients using oxygen therapy.

See also[edit]

References[edit]

  1. ^ Rozen, T.D.; Fishman, R.S. (April 2013). "Demand valve oxygen: a promising new oxygen delivery system for the acute treatment of cluster headache". Pain Medicine. 14 (4): 455–459. doi:10.1111/pme.12055. PMID 23369112.
  2. ^ Rossi, Paolo (28 September 2016). "What is cluster headache? Fact sheet for patients and their families. A publication to mark Cluster Headache Day 2016". Functional Neurology. 31 (3): 181–183. doi:10.11138/FNeur/2016.31.3.181. PMC 5115234. PMID 27678213.
  3. ^ Petersen, Anja S; Barloese, Mads CJ; Lund, Nunu LT; Jensen, Rigmor H (23 March 2016). "Oxygen therapy for cluster headache. A mask comparison trial. A single-blinded, placebo-controlled, crossover study". Cephalalgia. 37 (3): 214–224. doi:10.1177/0333102416637817. PMID 27013239.
  4. ^ Taylor, Larry "Harris". "A Diver's Guide To Oxygen Therapy Apparatus". Retrieved 17 January 2019.
  5. ^ a b Sorrell, Lana; Bird, Nick (Fall 2012). "Tips for Better Oxygen Administration". Alert Diver. Retrieved 17 January 2019.
  6. ^ Kudrow M.D., Lee (January 1981). "Response of Cluster Headache Attacks to Oxygen Inhalation". Headache. 21 (1): 1–4. doi:10.1111/j.1526-4610.1981.hed2101001.x. PMID 7007285.
  7. ^ a b Cohen, Anna S; Burns, Brian; Goadsby, Peter J (13 December 2009). "High-Flow Oxygen for Treatment of Cluster Headache: A Randomized Trial (2009)". JAMA. 302 (22): 2451–7. doi:10.1001/jama.2009.1855. PMID 19996400.
  8. ^ a b Rozen, Todd D (10 August 2004). "High oxygen flow rates for cluster headache". Neurology. 63 (3): 593. doi:10.1212/01.WNL.0000133405.80679.4B.
  9. ^ May, A; Leone, M; Afra, J; Linde, M; Sandor, PS; Evers, S; Goadsby, PJ (October 2006). "EFNS guidelines on the treatment of cluster headache and other trigeminalautonomic cephalalgias". European Journal of Neurology. 13 (10): 1066–1007. doi:10.1111/j.1468-1331.2006.01566.x. PMID 16987158.
  10. ^ British Thoracic Society Emergency Oxygen Guideline Development Group (June 2017). "BTS guideline for oxygen use in adults in healthcare and emergency settings". Thorax. 72 (1). Retrieved 17 January 2019.
  11. ^ "Headache - cluster". NICE. National Institute for Health and Care Excellence. Retrieved 17 January 2019.
  12. ^ a b Denoble, Petar (Fall 2010). "Oxygen as Definitive Treatment". Alert Diver. Divers Alert Network. Retrieved 17 January 2019.
  13. ^ Peterson, Anja S; Barloese, Mads CJ; Lund, Nunu LT; Jensen, Rigmor H (6 February 2016). "Oxygen therapy for cluster headache. A mask comparison trial. A single-blinded, placebo-controlled, crossover study" (PDF). Cephalalgia. 37 (3): 214–224. doi:10.1177/0333102416637817. PMID 27013239. Retrieved 18 January 2019.
  14. ^ Peterson, Anja S; Barloese, Mads CJ; Lund, Nunu LT; Jensen, Rigmor H (6 February 2016). "Oxygen therapy for cluster headache. A mask comparison trial. A single-blinded, placebo-controlled, crossover study" (PDF). Cephalalgia. 37 (3): 214–224. doi:10.1177/0333102416637817. PMID 27013239. Retrieved 18 January 2019.