Table 2 The most common AEs and the expected temporal and dose relationship
Adverse Event | Clinical Relevance | Expected Event Rate (πM) |
|---|---|---|
Pneumothorax Induced by HBO therapy | Abnormal collection of air in the pleural space between the lung and the chest wall, can result in steadily worsening oxygen supply. This is a pressure related phenomenon that can also be caused by major trauma or medical procedure. As an AE it is expected to increase as a function of dose atmospheres, but not duration of exposure or number of days treatment. This is expected to occur during the dive and would result in aborting the treatment. | 2% |
Signs of Pulmonary Dysfunction | Signs of pulmonary dysfunction, including PaO2/FiO2 ≤ 200 or requiring PEEP > 10 cm of water to maintain a PaO2/FiO2 ratio of > 200. This is an adverse event which may be related to total oxygen toxicity exposure and as such should increase with dose and number of treatments. Symptoms are expected to progressively worsen over subsequent dives. | 25% |
Pneumonia | This is an adverse event which is related to total oxygen toxicity exposure and as such should increase with dose and number of treatments. Symptoms are expected to progressively worsen over subsequent dives. | 40% |
Critical decreased CPP (< 60 mmHg) | This AE is not specific to HBO therapy, but is associated with poor outcome (reperfusion). It is expected to be the same in all groups but could demonstrate differences if the process of transferring to the dive chamber causes increased AEs. This should be analyzed as active vs. control. | 75% |
Critical hypotension (MAP< 70 mmHg) | This AE is not specific to HBO therapy, but can be related to transfer from critical care unit (e.g. disconnecting and reconnecting of lines). It is expected to be the same in all groups but could demonstrate differences if the process of transferring to the dive chamber causes increased AEs. This should be analyzed as active vs. control. | 75% |
Seizures during HBO treatment | These are expected to occur immediately proximal to treatment as a function of dose oxygen toxicity (rather than cumulative exposure). It is possible to have multiple episodes of AE. Subjects with a baseline propensity to seize may elevate the numerator for this AE. | 1% |
Hypercarbia during transportation (PaCO2 > 45 mmHg) | This AE is not specific to HBO therapy, but related to transfer from critical care unit (e.g. disconnecting and reconnecting of lines). It is expected to be the same in all groups but could demonstrate differences if the process of transferring to the dive chamber causes increased AEs. This should be analyzed as active vs. control. | 10% |