| Let us first begin by knowing what exactly hyperbaric | | | | oxygen delivery to tissue. Because it causes |
| oxygen treatment is. Hyperbaric oxygen therapy | | | | decreased blood flow, hyperbaric oxygen treatment |
| involves inhaling 100% oxygen at greater than one | | | | decreases swelling, including swelling in the brain, after |
| atmosphere absolute (ATA) in a pressurized chamber. | | | | injury or ischemia. |
| The air we breathe at sea level is defined as 1 ATA. | | | | |
| | | | | One of the properties of HBOT that is rarely |
| Many of the clinical uses of hyperbaric treatments | | | | discussed is the anti-inflammatory effect of HBOT. |
| conducted in fixed or portable hyperbaric chambers | | | | Several animal studies have revealed that hyperbaric |
| have been at pressures above 1.5 ATA. However, | | | | oxygen therapy has potent anti-inflammatory tissue |
| recently, some researchers have been using lower | | | | effects with equivalence to diclofenac 20 mg/kg noted |
| pressures of hyperbaric oxygen therapy with good | | | | in one study using HBOT at 2.4 ATA and 100% |
| results in some conditions. The abbreviation | | | | oxygen. |
| conventionally used for hyperbaric oxygen therapy is | | | | |
| HBOT. | | | | Hyperbaric oxygen treatmentusually conducted in a |
| What actually happens in a portable hyperbaric | | | | portable hyperbaric chamberhas also been shown to |
| chamber-? | | | | decrease markers of inflammation including IL-1, IL-6 |
| HBOT increases the amount of oxygen that is carried | | | | and TNF-á in humans. So we get decreased blood |
| in the plasma. Typically, hemoglobin which circulates in | | | | flow, increased oxygenation, decreased swelling and |
| the blood stream carries almost all of the oxygen in | | | | decreased inflammation, all from one treatment. |
| our body to tissues. | | | | |
| Only 0.3% of oxygen is dissolved in the plasma which | | | | How safe is HBOT? |
| is the fluid in our blood vessels not counting the red | | | | There have been numerous studies in adults and |
| cells, white cells and platelets. Hemoglobin is normally | | | | children which have established the safety of HBOT. |
| 97% saturated or full ofoxygen. | | | | The most common side effect of HBOT is middle ear |
| | | | | barotrauma where the ear drum gets irritated, bleeds |
| However, with HBOT, the amount of oxygen that is | | | | or even ruptures. This occurs in approximately 2% of |
| dissolved into the plasma can increase many fold. In | | | | patients. The incidence of this is decreased with |
| fact, some animal studies have shown that hyperbaric | | | | pseudoephedrine treatment before HBOT. |
| oxygen treatment can keep an animal alive without | | | | |
| circulating red blood cells. There is an old paper called | | | | Less common side effects in descending order include |
| "Life without blood" that studied this in a pig. Therefore, | | | | sinus squeeze which is a sharp pain in the sinus, |
| in conditions where hypoxia (or decreased amount of | | | | serous otitis which is fluid build-up behind the eardrum, |
| oxygen) is present, such as with decreased blood | | | | claustrophobia, and reversible myopia which is |
| flow, we would expect HBOT to help overcome this | | | | nearsightedness. Seizures may occur infrequently in |
| problem. | | | | about 1-3 out of 10,000 patients. Higher pressures |
| | | | | especially over 2-3 ATA have a higher incidence of |
| Interestingly, HBOT causes vasoconstriction of blood | | | | side effects. We need to remember that oxygen is a |
| vessels which actually causes decreased blood flow. | | | | drug. And just like any drug, it has beneficial effects at |
| However, because it increases the amount of oxygen | | | | a certain dose, but too high of a dose can increase |
| in plasma so much, the overall result is increased | | | | side effects. |