Clinical Trial – Effects of Repetitive Hyperbaric Oxygen Therapy in Patients With Acute Ischaemic Stroke

Background and Rationale:

Cerebrovascular disease is always ranked at the top causes of death and most of hospitalized
acute stroke patients have ischemic stroke [1].

Although the mortality rate of acute ischemic stroke is less than that of hemorrhagic stroke
[1], it still results in patient disabilities and complications that often lead to
significant costs to individuals, families, and society.

Traditional treatment for acute ischemic stroke includes thrombolytic therapy by injecting
tissue plasminogen activator (t-PA) within three hours after onset of symptoms [2],
antiplatelets and/or anticoagulant agents administered within the first 48 hours. Clinically,
the narrow time window of thrombolytic therapy and coexisting contraindications limit the use
of t-PA [2]. Thus, searching for an effective supplemental treatment for acute ischemic
stroke is imperative.

Hyperbaric oxygen therapy (HBOT) is valuable in treating acute carbon monoxide poisoning
[3,4], air or gas embolism [5], facilitating wound healing [6] and has been used as an
adjuvant treatment for many neurological disorders that need further study as concussion [7]
, stroke [8,9], cerebral palsy [ 10],traumatic brain injury [ 11], cerebral air embolism
[12], Autism [13] and multiple sclerosis [14].

Indications of hyperbaric oxygen therapy recommended by undersea and hyperbaric medical
society (UHMS) [15] are 1.air or gas embolism [5], 2.carbon monoxide poisoning [3,4],
3.clostridial myositis and myonecrosis [16], 4.crush injury, compartment syndrome and other
acute traumatic ischemias [17], 5.decompression sickness [18], 6.arterial insufficiencies
[19], 7.severe anemia [20], 8.intracranial abscess [21], 9.necrotizing soft tissue infections
[22],10. refractory osteomyelitis [23], 11.delayed radiation injury [24], 12.compromised
grafts and flaps [25], 13.acute thermal burn injury [26] and 14.idiopathic sudden
sensorineural hearing loss [27].

Known mechanisms of HBOT-induced neuroprotection include enhancing neuronal viability via
increased tissue oxygen delivery to the area of diminished blood flow, reducing brain edema,
and improving metabolism after ischemia [28,29]. Furthermore, a recent study performed on a
rat suggested that upregulation of the expression of glial derived neurotrophic factor (GDNF)
and nerve growth factor (NGF) might underlie the effect of HBOT [30].

The effectiveness of use of Hyperbaric oxygen therapy in human ischemic stroke is still
controversial that need further evaluation.

Patterns of treatment of osteoradionecrosis with hyperbaric oxygen therapy in the United Kingdom.

We aimed to find out the number of patients with osteoradionecrosis (ORN) being treated by hyperbaric chambers in the UK during 2006-07, and the protocols that were being used. We did a telephone survey of 76 chambers to find out whether they treated patients with ORN, how many patients they treated in 2006-07, what chamber pressure they used, the duration of each session, and the total number of sessions/patient. A total of 25 chambers treated 273 patients with ORN in 2006-07; 10 were listed by the British Hyperbaric Association (BHA) and 15 were at multiple sclerosis (MS) centres. MS centres treated 23 (8%) of patients with ORN with a variable number of sessions of shorter duration and lower pressures than the chambers listed by the BHA. Most BHA chambers treated patients at 2.2 ATA for 90 min/session with 30 preoperative and 10 postoperative sessions/patient.