My favorite topic... Oxygen Therapy as a cluster headache abortive…  Thank you Chuck…  I was hoping to be able to brief some of the following info at Dallas, but timing and the agenda just didn’t work out so here goes...  I’ll be able to reach more of you this way. 

I've been doing more research and collecting additional data on abort times as they relate to oxygen flow rates, non-rebreather (NRB) masks, and carbon dioxide (CO2) buildup and how these factors impact the effectiveness of oxygen therapy to abort cluster headache attacks.  The buzzword is hyperventilation.

In keeping with the standard disclaimer, I’ve provided the following for information purposes only.  See your doctor or neurologist for medical advice and treatment of your cluster headaches.  They’ll catch up with us at some point.
     
An oxygen flow rate of 12-15 liters/minute with a non-rebreather mask is a MUST on your prescription for oxygen therapy, as is the phrase, "AS NEEDED FOR CLUSTER HEADACHES."

In practice, 15 liters/minute is the minimum effective oxygen flow rate used by most successful oxygen therapy users – the really successful oxygen therapy users have oxygen regulators capable of delivering 25 liters/minute or higher.  Any flow rate less than 15 liters/minute, for example at 7 to 9 liters/minute, can easily result in a build up of CO2 due to the increased physical activity associated with the cluster headache attack AND the restricted respiration rate caused by the non-rebreather mask.  All this results in a situation where you cannot achieve an abort with oxygen therapy when the respiration rate is constrained by using low oxygen flow rates administered with a non-rebreather mask.

Although an oxygen flow rate of 7 to 9 liters/minute will easily result in a hemoglobin oxygen saturation at or near 100% under normal conditions, a respiration rate constrained to this flow rate by using a non-rebreather mask will result in a CO2 build up well above normal and displace or not leave room for oxygen molecules to attach to the hemoglobin in each red blood cell.  In short, while you may be getting more oxygen than normal at a flow rate of 7 to 9 liters/minute, the restricted respiration rate allows CO2 in the arterial blood steam to climb above normal levels.

It gets worse…  It's not the lack of oxygen that controls the rate of respiration, it's the level of CO2.   During strenuous activity, CO2 builds up faster in the bloodstream than it can be expelled from the lungs at normal respiration rates.  As a result, chemical receptors in the body signal an increase in respiration to reduce CO2 levels, and you start gasping for breath panting like a big dog. 

On top of that, CO2 is a powerful vasodilator.  As a cluster headache attack is associated with a dilation of the arteries and vascular structures around your trigeminal nerve, a buildup of CO2 above normal levels causes increased vascular dilation and that makes cluster headache attacks more painful and last longer. 

CO2 is such a powerful a vasodilator that even a slight increase in CO2 above normal levels will totally negate and overpower the vasoconstriction (a cluster headache abortive mechanism) provided by breathing 100% oxygen.  As CO2 levels continue to build, you start having panic attacks and become even more animated generating more CO2.  It's a vicious cycle.

The only way to prevent CO2 buildup during oxygen therapy is breathe at a rate faster than normal and with a greater tidal volume than normal.  This is called hyperventilation and requires a minimum oxygen flow rate of 25 liters/minute. 

Preventing CO2 buildup may not be possible at high Kip-levels even with an oxygen flow rate of 15 liters/minute and a properly functioning non-rebreather mask.  A higher respiration rate (and oxygen flow rate) will be needed when cluster headache attacks rise above Kip-6 to Kip-7 on the pain scale.

The normal adult respiration rate at rest is 15 to 18 respiration cycles/minute with an average of a half liter tidal volume.  Tidal volume is the volume of air inhaled and exhaled with each breath.  If you do the math, a flow rate of 7 to 9 liters/minute and a tidal volume of .5 liters, works out to a respiration rate of 14 to 18 cycles/minute.  At an oxygen flow rate of 15 liters/minute and a tidal volume of 1 liter, the respiration rate is 15 cycles/minute.  Again, even that respiration rate will be insufficient to cast off excess CO2 during a high Kip-level attack while you’re dancing around the room doing the tarantella (or Cha-Cha) and banging your head off the wall.

At this point, I can hear some of you saying…  Who is this guy and what heck is he trying to tell us and why?   

The answers are simple.

I’m an old Navy fighter pilot with over 3000 hours flying Navy jets.  All of that flight time was spent breathing 100% oxygen continuously from takeoff to touch down on missions lasting over 2 hours and on some extended mission lasting up to 7 hours.  I can also guarantee you that I would routinely suck down that 100% oxygen at flow rates well above 30 liters/minute at high respiration rates. 

I’m still here… so the safety of breathing that much 100% oxygen for periods of 2 hours or more is not an issue.  In fact, the US Navy has been requiring Navy and Marine Corps pilots flying tactical fixed-wing aircraft to breathe 100% oxygen from takeoff to touch down for over 60 years.
     
I’ve also been using oxygen therapy since I went chronic over 4 years ago and for the last two, at flow rates well above 15 liters/minute.  I’ve not used any other cluster headache medication except oxygen in the last 2 years and now routinely abort my attacks in two to three minutes.

The message of this post is equally simple.  Hyperventilation with 100% oxygen is the key to successfully aborting cluster headache attacks.  Oxygen is good and CO2 is bad. 

If you don’t believe me, watch the video of Chuck from the cluster headache documentary.  Pay close attention to the reservoir bag as it collapses completely with each breath he takes from his non-rebreather oxygen mask.  He was getting plenty of oxygen but he was unable to cast off excess CO2 with a high enough respiration rate due to the constrained oxygen flow rate.  That made the oxygen therapy ineffective and the very painful attack last far too long.

Take care.  I'm only trying to help.  'Hope to see some of you in Dallas so I can show you how well properly administered oxygen therapy works.

V/R, Batch