Delayed recompression for decompression sickness: retrospective analysis.

Most cases of decompression sickness (DCS) occur soon after surfacing, with 98% within 24 hours. Recompression using hyperbaric chamber should be administrated as soon as feasible in order to decrease bubble size and avoid further tissue injury. Unfortunately, there may be a significant time delay from surfacing to recompression. The time beyond which hyperbaric treatment is non effective is unclear. The aims of the study were first to evaluate the effect of delayed hyperbaric treatment, initiated more than 48 h after surfacing for DCS and second, to evaluate the different treatment protocols.From January 2000 to February 2014, 76 divers had delayed hyperbaric treatment (≥48 h) for DCS in the Sagol center for Hyperbaric medicine and Research, Assaf-Harofeh Medical Center, Israel. Data were collected from their medical records and compared to data of 128 patients treated earlier than 48 h after surfacing at the same hyperbaric institute.There was no significant difference, as to any of the baseline characteristics, between the delayed and early treatment groups. With respect to treatment results, at the delayed treatment divers, complete recovery was achieved in 76% of the divers, partial recovery in 17.1% and no improvement in 6.6%. Similar results were achieved when treatment started early, where 78% of the divers had complete recovery, 15.6% partial recovery and 6.2% no recovery. Delayed hyperbaric treatment using US Navy Table 6 protocol trended toward a better clinical outcome yet not statistically significant (OR=2.786, CI95%[0.896-8.66], p=0.07) compared to standard hyperbaric oxygen therapy of 90 minutes at 2 ATA, irrespective of the symptoms severity at presentation.Late recompression for DCS, 48 hours or more after surfacing, has clinical value and when applied can achieve complete recovery in 76% of the divers. It seems that the preferred hyperbaric treatment protocol should be based on US Navy Table 6

Clinical outcome and the treatment tables.

<p>* 84% and 13% of divers treated with US Navy Table 6 had complete and partial recovery compared to 66.7% and 18.5% in divers treated with 2 ATA table for 90 minutes. US Navy Table 6 had better clinical outcome than Table 2 ATA table, yet not statistically significant (<i>χ</i>² = 3.26 df = = 1 p = 0.07). Graph values shown in %.</p

Clinical outcome of the early and delayed groups.

<p>* Clinical outcome was not significantly different between the delayed and early groups (<i>χ</i>² = 0.093, p = 0.955). Clinical outcome was divided to an ordinal variable of 3 values as shown. Graph values shown in %.</p

Clinical outcome and time to recompression in the delayed treatment group.

<p>* Treatment after 48, 72 and 96 hours from surfacing showed no significant differences in clinical outcome. Time to recompression was not associated with clinical outcome. Graph values shown in %.</p

Flow chart describing study groups.

<p><b>*</b> The divers were divided into early recompression group (<48 hours) and delayed recompression group (≥48 hours from surfacing). The delayed group was further divided by the time to symptoms onset.</p

Patients' Baseline characteristics: Early (<48 hours) and Delayed (≥48 hours) recompression groups.

<p>Delayed group was further divided by symptoms onset (≤12 and >12 hours from surfacing)</p><p>Patients' Baseline characteristics: Early (<48 hours) and Delayed (≥48 hours) recompression groups.</p

Published studies in the last decades showing the association between clinical outcome and time to recompression.

<p>Notice time to recompression was calculated from symptoms onset in most cases.</p><p>Most studies reports include very small cohorts, only few divers treated later than 24 hours.</p><p>Published studies in the last decades showing the association between clinical outcome and time to recompression.</p

Hyperbaric oxygen induces late neuroplasticity in post stroke patients--randomized, prospective trial.

Recovery after stroke correlates with non-active (stunned) brain regions, which may persist for years. The current study aimed to evaluate whether increasing the level of dissolved oxygen by Hyperbaric Oxygen Therapy (HBOT) could activate neuroplasticity in patients with chronic neurologic deficiencies due to stroke.A prospective, randomized, controlled trial including 74 patients (15 were excluded). All participants suffered a stroke 6-36 months prior to inclusion and had at least one motor dysfunction. After inclusion, patients were randomly assigned to "treated" or "cross" groups. Brain activity was assessed by SPECT imaging; neurologic functions were evaluated by NIHSS, ADL, and life quality. Patients in the treated group were evaluated twice: at baseline and after 40 HBOT sessions. Patients in the cross group were evaluated three times: at baseline, after a 2-month control period of no treatment, and after subsequent 2-months of 40 HBOT sessions. HBOT protocol: Two months of 40 sessions (5 days/week), 90 minutes each, 100% oxygen at 2 ATA. We found that the neurological functions and life quality of all patients in both groups were significantly improved following the HBOT sessions while no improvement was found during the control period of the patients in the cross group. Results of SPECT imaging were well correlated with clinical improvement. Elevated brain activity was detected mostly in regions of live cells (as confirmed by CT) with low activity (based on SPECT) - regions of noticeable discrepancy between anatomy and physiology.The results indicate that HBOT can lead to significant neurological improvements in post stroke patients even at chronic late stages. The observed clinical improvements imply that neuroplasticity can still be activated long after damage onset in regions where there is a brain SPECT/CT (anatomy/physiology) mismatch

Clinical outcome by treatment table divided to severity subgroups.

<p>* Divers with moderate symptoms treated with US Navy Table 6 had 84.6% complete recovery compared to 71.4% in divers treated with 2 ATA table for 90 minutes (<i>χ</i>² = 6.26, df = 2, p = 0.04). Note US Navy Table 6 results in a trend to better outcome irrespective of severity of symptoms, yet in mild and moderate symptoms, it did not reach statistical significance.</p

Symptoms distribution: Early (<48 hours) and Delayed (≥48 hours) recompression groups’ symptoms distribution.

<p>Symptoms distribution: Early (<48 hours) and Delayed (≥48 hours) recompression groups’ symptoms distribution.</p