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Effect of hyperbaric oxygen on patients with traumatic brain injury


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Hyperbaric oxygen therapy (HBOT) is the medical therapeutic use of oxygen at a higher atmospheric pressure. The United States Food and Drug Administration have approved several clinical applications for HBOT, but HBOT in traumatic brain injury (TBI) patients has still remained in controversial. The purpose of our study is to evaluate the benefit of HBOT on the prognosis of subacute TBI patients. We prospectively enrolled 44 patients with TBI from November 1, 2004 to October 31, 2005. The study group randomly included 22 patients who received HBOT after the patients' condition stabilization, and the other 22 corresponding condition patients were assigned into the matched control group who were not treated with HBOT. The clinical conditions of the patients were evaluated with the Glasgow Coma Scale (GCS) and Glasgow Outcome Scale (GOS) before and 3 to 6 months after HBOT. The GCS of the HBOT group was improved from 11.1 to 13.5 in average, and from 10.4 to 11.5 (p < 0.05) for control group. Among those patients with GOS = 4 before the HBOT, significant GOS improvement was observed in the HBOT group 6 months after HBOT. Based on this study, HBOT can provide some benefits for the subacute TBI patients with minimal adverse side effects.
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Acta Neurochir Suppl (2008) 101:145-149
9 Springer-Verlag 2008
Printed in Austria
Effect of hyperbaric oxygen on patients with traumatic brain injury
J. W. Lin 1'2, J. T. Tsai 3,4, L. M. Lee 5,6, C. M. Lin 1,2, C. C. Hung 7, K. S. Hung 1, W. Y. Chen 1,
L. Weil, Co P. Kol, y. K. Sul , W. T. Chiu 1,6
1 Department of Neurosurgery, Taipei Medical University-Wan Fang Hospital, Taipei, Taiwan
2 Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
3 Institute of Biomedical Engineering, National Yang-Ming University, Taipei, Taiwan
4 Department of Radiation-oncology, Taipei Medical University-Wan Fang Hospital, Taipei, Taiwan
5 Department of Urology, Taipei Medical University-Wan Fang Hospital, Taipei, Taiwan
6 Graduate Institute of Injury Prevention and Control, Taipei Medical University, Taipei, Taiwan
7 Department of Neurosurgery, Taipei Medical University Hospital, Taipei, Taiwan
Hyperbaric oxygen therapy (HBOT) is the medical therapeutic use of
oxygen at a higher atmospheric pressure. The United States Food and
Drug Administration have approved several clinical applications for
HBOT, but HBOT in traumatic brain injury (TBI) patients has still
remained in controversial. The purpose of our study is to evaluate the
benefit of HBOT on the prognosis of subacute TBI patients. We pro-
spectively enrolled 44 patients with TBI from November 1, 2004 to
October 31, 2005. The study group randomly included 22 patients who
received HBOT after the patients' condition stabilization, and the other
22 corresponding condition patients were assigned into the matched
control group who were not treated with HBOT. The clinical conditions
of the patients were evaluated with the Glasgow Coma Scale (GCS) and
Glasgow Outcome Scale (GOS) before and 3 to 6 months after HBOT.
The GCS of the HBOT group was improved from 11.1 to 13.5 in
average, and from 10.4 to 11.5 (p <0.05) for control group. Among
those patients with GOS = 4 before the HBOT, significant GOS im-
provement was observed in the HBOT group 6 months after HBOT.
Based on this study, HBOT can provide some benefits for the subacute
TBI patients with minimal adverse side effects.
Traumatic brain injury; hyperbaric oxygen; Glasgow
Coma Scale (GCS); Glasgow Outcome Scale (GOS).
Traumatic brain injury (TBI) is a major cause of death
and disability. Every year in the United States, there are
about one million head-injured people treated in hospital
emergency rooms, and roughly 50,000 people die from
Correspondence: Wen-Ta Chiu, M.D., Ph.D., Department of
Neurosurgery, Taipei Medical University-Wan Fang Hospital; Graduate
Institute of Injury Prevention and Control, Taipei Medical University;
111, Section 3, Hsing-Long Road, Taipei 116, Taiwan.
e-mail: wtchiu
TBI [8], 230,000 people are hospitalized, and 80,000
survive with significant disabilities. Because of the enor-
mous medical expenditure resulting from such injury,
many efforts have been devoted to minimize the influ-
ence of TBI.
Clinically, there are two mechanisms directly related
to the TBI outcome. The first one is the primary insult,
which results from the impact itself, and all the neuronal
damages are determined by the impact. As this insult has
already occurred before the patient comes to hospital,
there is little that a medical team can do for the patient.
The second mechanism is the delayed non-mechanical,
which results from tissue edema after the impact follow-
ed by ischemic change inside the brain. This theoretical-
ly preventable or treatable condition is the principal
target of treatment for TBI. All the medical treatment
should therefore be devoted to minimize edema and fa-
cilitate cerebral blood flow, to enhance cerebrovascular
autoregulation, to reduce cerebral metabolic dysfunc-
tion, and to adequately maintain cerebral oxygenation
[7]. Furthermore, excitotoxic cell damage and inflamma-
tory process resulting from ischemia may also lead to
increased cell death [12]. Generally speaking, about
80% of deaths in TBI result from hypoxia. Consequent-
ly, oxygen supplement in the initial resuscitation of a
TBI patient is of paramount importance.
Hyperbaric oxygen therapy (HBOT) is the medical
use of oxygen at a pressure exceeding atmospheric pres-
sure (ATA). The mechanism of HBOT consists in dras-
tically increasing oxygen partial pressure of the tissues,
146j. w. Lin et al.
and facilitating the oxygen transport by plasma. As a
result, HBOT can improve oxygen supply to the injured
brain and diminish the volume of brain that will necro-
tize during ischemia [5, 11].
Materials and methods
In this prospective cohort study, we intended to study the impact of HBOT
on moderate to severe TBI patients. The protocol of this study was ap-
proved by the Investigation Review Board-Wanfang Medical Center
(approval no. F950305). All the patients were enrolled under the regula-
tion of inclusion and exclusion criteria, and the criteria were as follows.
Inclusion criteria
1. Age _> 16 y/o (Pediatric patient was excluded).
2. The patients were diagnosed to have moderate to severe TBI.
(Glasgow Coma Scale (GCS) from 3 to 12).
3. TBI condition stabilization.
4. Stable vital sign and spontaneous respiration without endotracheal
intubation or mechanical ventilation (tracheotomy was eligible for
the enrollment).
5. No active infection or leucocytosis.
6. A hyperbaric oxygen department physician was consulted, and he
(she) agreed to treat the patient with HBOT.
7. Informed consent could be obtained from the patient's family.
Exclusion criteria
1. Medical history with central nervous system disease (e.g. Parkinson
disease, dementia, congenital anomaly, stroke.., etc.)
2. Systemic disease history (e.g. diabetes, coronary artery disease, renal
insufficiency, COPD... etc.)
3. Multiple traumas (e.g. Chest contusion, abdominal blunt injury,
internal bleeding, pelvic fracture.., etc.)
4. Skull base fracture with CSF rhinorrhea or otorrhea.
5. Smoking or alcoholism.
6. Hemoglobin _< 10 gm/dl for female or < 12 gm/dl for male patients.
When the patients were enrolled, the assignment will be decided. If
one patient was chose randomly to be a study group candidate then there
will be another patient with corresponding condition (e.g. age, sex,
clinical course, severity and condition.., etc.) chose to be the matched
control group patients. If the patient was chose to be the study candidate,
the potential risk and benefit will be explained to the family for the
obtaining of the treatment consent. From Nov. 1, 2004 to Dec. 31, 2006,
there were total 62 patients enrolled into his study. Finally, there were 44
complete patients' data available for the further analysis.
In this research, we used a multi-user pressurized chamber (Model
no.: BTG/875/PV/02GOC-100, Apex Process Technologies (S) FFE
LTD, Singapore) to treat patients. The HBOT protocol was to apply two-
hour, two ATA pressures in the process. We increased the air chamber
pressure slowly to 2 ATA over 15 min and maintained this pressure for
90min. Patients were given 100% oxygen with 02 masks. Then we
depressurized to normal ATA over 15 min. The full treatment course
was defined as once a day for 20 days over a 4 week period. [9] During
the HBOT the patients' condition and vital sign were closely monitored.
If there was any complication (e.g. hypotension, short of breath, seizure,
unstable vital sign (blood pressure increased or decreased larger than
20mmHg), hypoxia (SaO2 <95%)... etc.) happened during HBOT, the
treatment for this patient will be discontinued, and this patient and the
corresponding controlled one will be excluded. The purpose of our study
was to clarify the influence on HBOT in subacute TBI patients by
analyzing patients' demographic information, GCS changes, and com-
paring variables such as the GCS, the injury severity, and the length of
time of HBOT, with regard to the subacute TBI outcome. And the TBI
outcomes were evaluated with the Glasgow Outcome Scale (GOS) con-
sisting of 5 levels (1: Death, 2: Vegetative status, 3: Severe disability, 4:
Moderate disability, and 5: Good recovery).
After data collection, we analyzed the result with SPSS 11.0 software.
We compared the two groups by means of demographic information,
including sex, age, body weight, injury timing, the severity of head
injury, duration of hospital stay, treatment with received surgery or that
without surgery, and length of HBOT treatment time. We compared the
GCS and GOS scores of both groups at different times with the Chi-
square test to assess difference between the two groups. The patients
were stratified with different GOSb levels (GOS level before the HBOT)
(GOSb - 2, GOSb = 3, and GOSb -- 4). There was no GOSb - 1 and the
GOSb- 5 patients enrolled because GOSb = 1 patients died before the
Table 1. Demographic information for patients
HBOT group Control group
Total 22 22
M:F 19"3 19:3
Below 24 7 5
25-64 13 16
Above 65 2 1
Body weight (kg) 61.75 65.12
9-12 10 10
3-8 12 12
EDH 3 2
SDH 5 6
ICH 4 5
SAH 3 4
DAI 2 1
With 16 20
Without 6 2
4 7 6
2-3 15 16
GCS The patient initial GCS during admission.
GOSb The patient's GOS before HBOT or the same time for the control
group (mean 27.5 days after head trauma).
All variables have p > 0.05.
EDH Epidural hematoma, SDH subdural hematoma, ICH intracerebral
hemorrhage, SAH subarachnoid hemorrhage, DAI diffuse axonal injury.
Table 2. GCS improvement for the patients after HBOT
GCS mean GCS mean GCS mean
on arrival before HBOT after HBOT
HBOT group 8.0 11.1 13.5
Control group 7.9 10.4 11.5"
* p < 0.05 with significant difference.
Effect of hyperbaric oxygen on patients with TBI 147
Table 3. GOS outcome for the patients 3 and 6 months after HBOT
GOS3a without
improvement GOS3a with
improvement GOS6a without
improvement GOS6a with
improvement Total
GOSb -- 2 HBOT 8 3
control 8 2
GOSb = 3 HBOT 2 2
control 4 2
GOSb = 4 HBOT 3 4
control 3 3
Total 28 16
p < GOSb The patient's GOS before the HBOT or the same timing for the control group.
GOS3a The patient's GOS at 3-month post injury or at the same timing for control group.
GOS6a The patient's GOS at 6-month post injury or at the same time for control group.
p < 0.05 with significant difference.
HBOT and there was nothing could be improved for GOSb = 5 patients.
We recorded the GOS scores before (GOSb) and 3 (GOS3a) and 6
(GOS6a) months after HBOT or at the same time for the control group
patients to evaluate performance of the patients.
As showed in Table 1, 22 patients were enrolled in each
group. The M:F sex ratio was the same: 19:3 in both
groups. Most of the patients were aged between 25 and
64 years, which was also the most common range of age
for head injury. The average interval from injury to re-
ceiving HBOT was 27.5 + 5.8 days. This was also the
timing for the first GOS evaluation for both groups. If
the patients received HBOT, the average treatment times
were 24.4-+-7.8 times. In this table, no significant dif-
ference was found in age, sex, body weight, GCS severity,
presence or absence of surgical intervention, or GOS
severity between HBOT and control groups (all p > 0.05).
The average initial GCS scores for both groups' pa-
tients on arrival were 8.0 and 7.9, respectively. After
admission, surgical and/or medical treatments were ap-
plied to these patients, and the GCS recovery from 8.0 to
11.1 and from 7.9 to 10.4, respectively. We applied
HBOT to the patients after their traumatic condition
stabilization, and there was considerable improvement
in the HBOT group, from 11.1 to 13.5. In the control
group, GCS improved only from 10.4 to 11.5. Even in
this subacute stage of TBI, HBOT showed beneficial
effects on GCS improvement for moderate or severe
TBI patients (p<0.05) (Table 2).
The patients in both groups were stratified with the
GOSb level (GOSb = 2, 3, and 4) to evaluate the HBOT
effects on TBI patients. The outcome at the third and
sixth months after the HBOT was evaluated and analyzed.
In third month evaluation (Table 3), even though there
was some improvement in patients with HBOT, the num-
bers were not sufficient for drawing significant difference
and conclusion between study and control groups.
In sixth month evaluation (Table 3), there were 12
patients with improvement in the HBOT group, and 9
patients in the control group, but the difference did not
reach statistically significance (p > 0.05) for GOSb- 2 or
3 patients. However, there was a significant difference be-
tween these two groups among patients with GOSb : 4,
and as a whole the GOS6a (6 months after HBOT) im-
provement was greater in the HBOT group than in the
control group (p < 0.05).
Adverse event
Two patients developed seizures during the first week of
HBOT, and the convulsions were controlled with antic-
onvulsants. Then the patient resumed HBOT 2 weeks
later. Two patients experienced severe ear pain, and re-
ceived tympanostomy. Thereafter the ear pain subsided,
and the patient completed the full course of HBOT
successfully. No pulmonary adverse event, unstable vital
sign, or cataract occurred during HBOT or within 6
months follow-up. However, all these 4 study candidates
and their corresponding control patients were excluded.
The US Food and Drug Administration have approved
several clinical applications for HBOT. They included
certain non-healing wounds, radiation necrosis of soft
tissue and radiation osteonecrosis, carbon monoxide poi-
soning, decompression sickness, acute arterial ischemia,
and some sports injuries. These approvals did not in-
clude TBI. However, in the literature review; we found
reports showing some supports for HBOT application to
TBI patients.
148j. w. Lin
et al.
In 2004, the Agency for Healthcare Research and
Quality reviewed two fair-quality trials [1, 10], showing
fair evidence that HBOT might reduce mortality or the
duration of coma in severe TBI patients. But in one of
the trials, HBOT also implicated an increased chance for
poor functional outcome. Therefore, the evidences were
conflicting. Although these two trials are cited frequent-
ly, the methodologies of these two trials are also criti-
cized [6]. In the past, HBOT was used under the
concepts of improving TBI patients' outcome and miti-
gating social economical expenditure [2]. Previous stud-
ies have been focused on the immediate use of HBOT
after head trauma. However, during the initial period of
TBI, patients are often ventilator-dependent and may
have other associated injuries, such as lung contusion.
Under such situation, it is not convenient to treat TBI
patients with HBO early. With SPECT to show blood
flow improvement and to analyze them with different
age groups, Golden et al, reported that HBOT could im-
prove cerebral metabolism in the chronic stage of TBI
[4]. There are only limited data in the literature to sup-
port beneficial effects of HBOT on TBI patients with
different degrees of severity.
In some animal study [7], using 2.5 ATA HBOT could
reach maximum microcirculatory hemoglobin oxygen
saturation and 2 fold of normal hemoglobin circulation
but there was also higher complication, such as pulmonary
system barotrauma, cataract, glaucoma, seizure ... etc.
[6, 10, 11]. The Rockswold
et al.
reported that using
1.5 ATA HBOT for 60 min is relatively safe without any
oxygen toxicity [5, 11]. In our series, we used HBOT
with 2 ATA for 90 min every day for a total 20 times.
What the optimal oxygen atmospheric pressure and
duration used in HBOT is need further clarification.
The timing of using HBOT around one month (27.5 +
5.8 days) after TBI is more practical in clinical condi-
tion. At that stage, patients have become more stable for
their cardiopulmonary function and often have received
intensive rehabilitation. As a consequence, the frequen-
cy of HBOT-related respiratory complications will be
reduced. Furthermore, the synergistic effect of rehabili-
tation with HBOT conceivably triggers the improvement
of the patient's GOS in the sixth month.
The adverse events in this trial were rare. Only two
patients had seizures during the initial period of HBOT,
and another two had middle ear barotrauma. The sei-
zure incidence in the previous reports was 2.4 per 10,000
patient-treatments [ 13]. Because the population base was
different between our results and this report, and we
focused on the head trauma patients only, there should
be higher incidence of seizure attack during the HBOT.
Besides, the sample size of our patients was too small
for statistical comparison. The tympanic membrane tear
is common in HBOT [3]. However, in our HBOT center,
tympanoplasty was not routinely performed before
HBOT; this simple procedure should be considered
and performed before the HBOT to reduce the patient's
suffering. As the minor side effects, such as tinnitus,
aural fullness, disequilibrium, and vertigo and or nau-
sea, these side effects were all well tolerated by the
patients [9].
In this trial, we demonstrated that the GCS of TBI
patients in the HBOT group recovered significantly bet-
ter than in the control group (p <0.05) (Table 2). This
result would indicate that HBOT has a positive benefit in
GCS recovery of TBI patients. For the GOS improve-
ment, there was no obvious difference, especially for the
3 months follow-up (Table 3). Why did GCS improve so
much, and GOS did not? GOS is widely applied for TBI
patient outcome evaluation, but the intervals used for
GOS scores are too rough. In recent studies, an extended
GOS was used to evaluate the outcome of the TBI
patients, and more detailed evaluation might help our
future study.
For the patients receiving HBOT, there was no im-
provement of GOS in the third month follow-up, but 6
months after HBOT, GOSb=4 group got some im-
provement (Table 3). This situation could be explained
by the delayed effect of HBOT. That means HBOT
needs some more time to express the effects.
The TBI patients with GOSb-- 4 showed signifi-
cant GOS improvement six months after HBOT in the
study group (p<0.05, Table 3). But there was no such
difference in the GOSb-2 or GOSb=3 groups. In
GOSb = 2 (vegetative state) and GOSb = 3 (severe dis-
ability) patients, there should be severe parenchymal
damages in the cerebral cortex. HBOT can not re-
generate necrotic neurons, but can only improve reox-
ygenation of the brain parenchyma. With incorporation
of rehabilitation, HBOT can help patients with mild
neurological deficits to recover and return to normal
life. In this prospective study, we can conclude that
HBOT can help TBI patients in GCS recovery and also
help patients with mild functional disability to lead a
better life.
The authors would like to acknowledge the grant from the Department
of Health, Executive Yuan, Taiwan (DOH-TD-B-111-002), the grant
Effect of hyperbaric oxygen on patients with TBI 149
(NHRI-EX97-9707PI, NHRI-CN-HD9503S) from National Health Re-
search Institute, Taiwan, the grant (NSC 96-2314-B-038-010-MY2)
from National Science Council, Taiwan, and the grant (96001-62-010)
from Department of Health, Taipei, Taiwan.
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... Our search identified 282 unique, potentially relevant articles. We included 3 good-quality systematic reviews 26,50,51 which included 15 RCTs (in 19 publications), [23][24][25]29,[52][53][54][55][56][57][58][59][60][61][62][63][64][65][66][67][68] and one subsequently published RCT (in 4 publications), 69,70 for a total of 26 publications (Table 1; see supplemental materials Appendix E for full evidence tables). Five RCTs [23][24][25][53][54][55]63,66,67,69,70 reported outcomes for patients with mild TBI with or without PTSD, 10 RCTs 29,52,57-62,64,65,68 reported outcomes for patients with moderate to severe TBI, and 1 RCT 56 failed to report on TBI severity. ...
... 95% CI 1.23 to 11.63) compared to the control groups based on 3 overall good-quality RCTs. 50 The GOS improvement was driven by a single study 65 performed in China with a control group where the mortality rate was almost double that observed in other included studies. 50 A sensitivity analysis after removal of this study 65 The applicability of these results to Veterans is likely low because none of these studies included current service members or Veterans or those with blast-induced TBI. ...
... 50 The GOS improvement was driven by a single study 65 performed in China with a control group where the mortality rate was almost double that observed in other included studies. 50 A sensitivity analysis after removal of this study 65 The applicability of these results to Veterans is likely low because none of these studies included current service members or Veterans or those with blast-induced TBI. Furthermore, the majority of TBIs in Veterans are mild -moderate to severe TBIs only make up 9.4% and 1.1%, respectively, of TBIs sustained by service members since 2000. ...
Technical Report
Full-text available
Hyperbaric oxygen therapy (HBOT) is designed to increase the supply of oxygen to our blood and tissues and is thought to have osmotic and angiogenesis effects. In normal air, the oxygen level is only around 21% and the atmospheric absolute (ATA) pressure at sea level is 760 mmHg. HBOT delivers 100% medical grade oxygen inside a chamber where the air pressure is raised at least 1.4 times greater than normal. HBOT has been described as a high-tech, high-touch treatment that can require daily 2-hour sessions for 8 to 10 weeks in which participants are assisted by one or more specially-trained HBOT technicians and are sometimes accompanied by other patients in ‘multiplace’ chambers. Following certain types of injuries, our bodies may demand more oxygen than is available in the normal air we breathe to supply our cells with the fuel necessary for healing processes (eg, metabolism, cellular growth and repair). The FDA has cleared HBOT, commonly at 100% oxygen delivered between 1.5 and 3.0 ATA, as a combination treatment of increased oxygen (hyperoxia) at increased hydrostatic pressure for several types of injury indications such as wound healing, necrotizing infections, burns, radiation injury, and carbon monoxide poisoning. Given the microscopic and macroscopic wounds to the white matter of the brain that have been attributed to traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD), HBOT has also been explored as a therapy for these conditions. It has been used anywhere from between 3 to 71 months post-injury for mild TBI and within 24 hours for moderate to severe TBI. Among people who sustain mild TBI, up to 85% report persistent post-concussion symptoms (PPCS). Of those with PPCS, at least 90% have at least one co-occurring behavioral health condition, such as PTSD, and together these conditions have been labeled ‘post-deployment syndrome’. Among people with PPCS, mild TBI, PTSD, and post-deployment syndrome, many do not achieve remission with recommended treatments; thus, there remains a great need for innovative therapies. In case series of TBI and/or PTSD populations, HBOT, mostly at 1.5 ATA, has statistically significantly improved cerebral blood flow and mean scores on post-concussion symptoms (PCS), PTSD, depression, and anxiety symptom checklists, as well as cognitive functioning and quality of life. Statistically significant mean improvement on physiological outcomes and checklists does not always equal clinically significant symptom benefits. To best demonstrate a net benefit, ideally HBOT would significantly improve clinically significant symptom response, function, and quality of life over a control group in randomized controlled trials (RCTs) of patients with mild to severe TBI and/or PTSD, without increasing risk of serious harm.
... X. Jiang et al., 2016;Morgan et al., 2012;Thibaut et al., 2019), surgical treatment (Thibaut et al., 2019), various sensory and nerve electrical stimulation therapies (Thibaut et al., 2019), traditional Chinese medicine treatments such as acupuncture and massage (D. X. Jiang et al., 2016), hyperbaric oxygen therapy (HBOT) (Lin et al., 2008), mild hypothermia therapy, and neural stem-cell therapy (D. X. Jiang et al., 2016). ...
... HBOT (Lin et al., 2008) has been used as a noninvasive treatment for the recovery of consciousness in patients with traumatic brain injury, stroke, and postcardiopulmonary resuscitation with some success. ...
Full-text available
Objective The objective of this study was to investigate the clinical efficacy of hyperbaric oxygen combined with right median‐nerve stimulation (RMNES) in patients with disorders of consciousness caused by brain injury. Methods A total of 120 patients with consciousness disorders caused by brain injury were selected. They were randomly divided into three groups, a control group, test group 1 (treated with RMNES after hyperbaric oxygen therapy [HBOT]), and test group 2 (treated with RMNES at the same time as HBOT), with 40 patients in each group. Before and after treatment, the Glasgow coma scale (GCS), brainstem auditory‐evoked potential (BAEP), electroencephalogram (EEG), and upper‐limb sensory‐evoked potential (USEP) were evaluated for the three groups of patients. Results The GCS score of patients in the three groups significantly improved compared with that before treatment (p < .05). There were significant differences in GCS scores among the three groups (p < .05), and the GCS score for the patients was test group 2>test group 1>control group. The EEG, BAEP, and USEP scores were significantly improved compared with those before treatment (p < .05), and the degree of improvement of patients in the three groups was test group 2>test group 1>control group (p < .05). The clinical efficacy of test group 2 was higher than that of test group 1, and the clinical efficacy of test group 1 was higher than that of the control group (p < .05). Conclusion Hyperbaric oxygen combined with RMNES can improve the state of consciousness and promote the recovery of consciousness for patients with consciousness disorders caused by brain injury, and the effect of RMNES combined with HBOT in the chamber on improving the recovery of consciousness is better than after HBOT outside the chamber.
... To date, several RCTs have been conducted on HBOT treatments to evaluate the therapeutic benefit, albeit the results have not provided consistent evidence. Several RCTs demonstrated a significant improvement in patient condition following HBOT treatments, [30][31][32] whereas other RCTs have demonstrated no difference between active treatment and sham or control conditions. 4,33,34 These conflicting results across multiple studies have raised questions not about the efficacy of the treatment, but rather the causality of individual improvement. ...
... Instead, participants breathe room air under pressurized conditions. 30,33 This approach achieves the experimental goal of masking the treatment condition, but even partial pressure increases the amount of dissolved oxygen concentrated in the blood. Thus, solving the masking challenge could actually induce the therapeutic benefit. ...
... 10 On the other hand, clinical evidence to support the neuroprotective properties of HBOT is limited. 11 In regard to the neuroprotective effects of HBOT, accumulating evidence indicates an association between the beneficial effects to a variety of biological properties mainly anti-oxidative, 12 antiinflammatory, 13 and anti-apoptotic properties, 14 in addition to improvement of oxygen supply and neural metabolism. 15,16 This paper presents an up-to-date review of the neuroprotective effects of HBOT with its molecular mechanisms in different models of neurological disorders in three parts. ...
... 164 To assess the beneficial effects of HBOT on the prognosis of patients with subacute TBI , the clinical status of the patients were assessed before and 3 to 6 months after HBOT with the Glasgow outcome and Glasgow coma scales. 11 The Glasgow coma and outcome scales of the HBOT group were improved 6 months after HBOT, with minimal adverse side effects. Meanwhile, another study revealed that HBOT (2.4 ATA) following mild TBI had no effect on post-concussive symptoms. ...
Hyperbaric oxygen therapy, intermittent breathing of 100% oxygen at a pressure upper than sea level, has been shown to be some of the neuroprotective effects and used therapeutically in a wide range of neurological disorders. This review summarizes current knowledge about the neuroprotective effects of hyperbaric oxygen therapy with their molecular mechanisms in different models of neurological disorders.
... The improvement in GCS in the HBOT group was higher than in the control group and this was statistically signicant. [11] In the study conducted by Lin et al., 44 patients were included in the study, with 22 patients randomly assigned into HBOT and control group. Patients with traumatic brain injury with GCS between 3 and 12 were included in the study. ...
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Traumatic brain injury (TBI) is a major health problem worldwide, resulting in signicant morbidity, mortality and the survivors are often left with cognitive and behavioural disabilities. Various treatment options in TBI are focussed on altering the secondary brain injury. Hyperbaric oxygen therapy (HBOT) is one such adjunctive treatments for TBI, which addresses the TBI induced ischemia and hypoxia. The present study was conducted to assess the role and efcacy of HBOT in patients with head injury mainly in terms of improvement of consciousness and cognitive functions. The study also assessed the level of disability and the level of recovery in patients with traumatic brain injury, immediately post therapy. A total of 120 patients with mild and moderate TBI were included in the present study, 60 patients each in the study or HBOT group and the control group. Depending upon the clinical and radiological ndings of the patients, the HBOT/study group received medical management and HBOT, whereas the control group received only medical management. The improvement in level of consciousness was assessed by Glasgow coma scale (GCS) score, Full outline of Unresponsiveness (FOUR) score. The level of cognitive improvement is assessed by the Ranchos Los Amigos scale and Montreal Cognitive assessment score. The level of disability was assessed by Disability Rating Scale (DRS) and the level of recovery was assessed by Glasgow Outcome Scale (GOS) and Glasgow Outcome Scale Extended (GOS-E) The HBOT group showed signicant improvement in the level of consciousness when compared to the control group. In terms of cognitive improvement, mixed results were obtained. However, there was no signicant difference in the level of disability and recovery post therapy in both the groups.
... However, in our practice of using 2.0 ATA HBO · 60, we did not find significant adverse effects, indicating that HBO is relatively safe, which is consistent with some other previous studies. 1,25,26 Although Lin et al. reported that using 2.0 ATA HBO for the treatment of subacute moderate/severe TBI induced occurrences of epilepsy in about 9% patients, 27 we did not encounter such a case in our study. ...
Objective: Traumatic brain injury (TBI) is a global public health problem. Hyperbaric oxygen (HBO) therapy may be beneficial for TBI because it improves cerebral blood flow into tissues exhibiting low blood flow. This was done to observe the clinical therapeutic effect of different intensities of rehabilitation training and HBO therapy in early stages of TBI. Approach: In this multicenter, randomized, stratified case-controlled prospective clinical trial, we selected 158 patients with moderate-severe TBI and assigned them into (1) a control group receiving routine once-daily (1/d) rehabilitation training without HBO, (2) study group A receiving routine 1/d rehabilitation training with HBO, (3) study group B receiving twice-daily (2/d) intensified rehabilitation training with HBO, and (4) study group C receiving 2/d intensified rehabilitation training without HBO, all for 3 months. The cognitive ability, activities of daily life (ADL), and movement ability were assessed before and after training with the Fugl-Meyer Assessment (FMA), Functional Independence Measure (FIM), Modified Barthel Index (MBI), and Mini-Mental State Examination (MMSE). Results: FIM, FMA, MBI, and MMSE scores were improved significantly after 1-, 2-, and 3-month rehabilitation training in all TBI patients (p < 0.01), and this improvement was especially remarkable in patients who received 2/d intensified rehabilitation training with HBO (p < 0.01). Innovation: With extensive and intensive research on TBI rehabilitation, it was proved that TBI rehabilitation intervention should be initiated as early as possible. Conclusion: Early intensified rehabilitation training in combination with HBO is more beneficial to the recovery of cognitive, ADL, and movement abilities of TBI patients.
... Substantial amount of evidences has been published indicating that HBOT can interfere with the processes that are following brain injury and moderate its consequences [14,[24][25][26][27]. Recent results of experimental and clinical studies and potential mechanisms of HBOT in TBI are reviewed by Wang et al. [28] and Hu et al. [7]. ...
... A study of HBO therapy used to treat sub-acute moderate to severe TBI at 2.0 ATA reported a 9% seizure rate (75). However, serious side effects from HBO therapy are rare in patients with chronic and mild TBI and a previous study demonstrated that patients with TBI treated with HBO do not experience any marked side effects (76). ...
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The present review evaluated the effect of hyperbaric oxygenation (HBO) therapy on post-concussion syndrome (PCS). Searches for publications from the earliest date possible up until the first week of 2016 were conducted using the electronic databases Cochrane, EBSCOhost, Embase, Ovid MEDLINE, PubMed and Web of Science. Additional trials were identified through reference list scanning. Randomized controlled trials assessing the effectiveness of HBO therapy in PCS were selected and tested for eligibility for inclusion in the present review. Two independent reviewers conducted data extraction and the Cochrane Collaboration’s recommended method was used to assess the risk of bias in each study included. Review Manager 5.3 software was used for data synthesis and analysis and the standardized mean difference (SMD) or mean difference (MD) was estimated with a fixed or random effects model using a 95% confidence interval (CI). A total of 127 articles were identified, 4 of which were eligible for final analysis. The meta-analysis identified no difference in the Rivermead Post-Concussion Symptoms Questionnaire (MD=1.23; 95% CI,-3.47-5.94; P>0.05; I²=35%) or Post-Traumatic Stress Disorder Checklist (PCL) scores (SMD=0.12; 95% CI,-0.31-0.54; P>0.05; I2=0%) scores between groups receiving different oxygen doses. The differences in PCL scores (SMD=-0.13, 95% CI,-0.80-0.53; P>0.05; I²=63%) and neurobehavioral symptoms (SMD=-1.00, 95% CI,-2.58-0.58; P>0.05; I²=92%) between the HBO and sham groups were not significant. The current study demonstrated that HBO therapy has no significant effect on PCS compared with the sham group. Therefore, it was determined that effective design and execution of a large clinical trial, which includes treatment, control and sham groups is required in the future.
Despite multiple prior pharmacological trials in traumatic brain injury (TBI), the search for an effective, safe, and practical treatment of these patients remain ongoing. Given the ease of delivery and rapid absorption into the systemic circulation, inhalational gases that have neuroprotective properties will be an invaluable resource in the clinical management of TBI patients. In this review, we perform a systematic review of both preclinical and clinical reports describing inhalational gas therapy in the setting of TBI. Hyperbaric oxygen which has been investigated for many years, and some of the newest developments are reviewed. Also, promising new therapies such as hydrogen gas, hydrogen sulfide gas, and nitric oxide are discussed. Moreover, novel therapies such as xenon and argon gases and delivery methods using microbubbles are explored. Key Words: traumatic brain injury, head trauma, oxidative stress.
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Hyperbaric oxygen therapy has been proposed as a method to treat traumatic brain injuries. The combination of pressure and increased oxygen concentration produces a higher content of dissolved oxygen in the bloodstream, which could generate a therapeutic benefit for brain injuries. This dissolved oxygen penetrates deeper into damaged brain tissue than otherwise possible and promotes healing. The result includes improved cognitive functioning and an alleviation of symptoms. However, randomized controlled trials have failed to produce consistent conclusions across multiple studies. There are numerous explanations that might account for the mixed evidence, although one possibility is that prior evidence focuses primarily on statistical significance. The current analyses explored existing evidence by calculating an effect size from each active treatment group and each control group among previous studies. An effect size measure offers several advantages when comparing across studies as it can be used to directly contrast evidence from different scales, and it provides a proximal measure of clinical significance. When exploring the therapeutic benefit through effect sizes, there was a robust and consistent benefit to individuals who underwent hyperbaric oxygen therapy. Placebo effects from the control condition could account for approximately one-third of the observed benefits, but there appeared to be a clinically significant benefit to using hyperbaric oxygen therapy as a treatment intervention for traumatic brain injuries. This evidence highlights the need for design improvements when exploring interventions for traumatic brain injury as well as the importance of focusing on clinical significance in addition to statistical significance.
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Hyperbaric oxygen treatment (HBOT) involves some risk of central nervous system (CNS) oxygen toxicity, which may be revealed by various signs and symptoms including seizures in patients breathing O2 at pressures of 2 ATA or higher. The aim of this study was to determine the incidence of such seizures in the Underwater and Hyperbaric Medicine Departments of two university hospitals. We retrospectively evaluated 80,679 patient-treatments for 9 clinical indications to determine the incidence of seizures attributable to CNS O2 toxicity. Because different protocols were used for HBOT, the treatments were studied in four groups according to the chamber type used and the medical facility at which it was located. Only 2 seizures were documented, yielding an incidence of 2.4 per 100,000 patient-treatments. Both cases occurred in a multiplace chamber pressurized to 2.4 ATA with O2 delivered by mask for three x 30 min with 5-min air breaks. The seizure incidence reported here is lower than other studies published in the literature. The delivery of O2 by mask rather than hood may be a factor. Nevertheless, it appears that the risk of seizures due to CNS O2 toxicity during HBOT is very low as long as appropriate exclusion criteria and treatment profiles are used.
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This critical literature review examines historical and current investigations on the efficacy and mechanisms of hyperbaric oxygen (HBO) treatment in traumatic brain injury (TBI). Potential safety risks and oxygen toxicity, as well as HBO's future potential, are also discussed. Directed literature review. Historically, cerebral vasoconstriction and increased oxygen availability were seen as the primary mechanisms of HBO in TBI. HBO now appears to be improving cerebral aerobic metabolism at a cellular level, namely, by enhancing damaged mitochondrial recovery. HBO given at the ideal treatment paradigm, 1.5 ATA for 60 minutes, does not appear to produce oxygen toxicity and is relatively safe. The use of HBO in TBI remains controversial. Growing evidence, however, shows that HBO may be a potential treatment for patients with severe brain injury. Further investigations, including a multicenter prospective randomized clinical trial, will be required to definitively define the role of HBO in severe TBI.
60 patients were included in a prospective study to evaluate the effectiveness of hyperbaric oxygenation (OHP) as a treatment of head injury coma. They were assigned to nine subgroups according to age, level of consciousness and eventual neurosurgical procedure, and then selected randomly for OHP or standard therapy. OHP was administered in one or several series of daily exposure at 2.5 ATA. However, the OHP therapy protocol was to be interrupted in 11 cases developing pulmonary, hyperoxic, or infectious complications. Overall mortality and mean duration of coma in survivors were not different in both groups, indicating that OHP was either ineffective or too intermittently applicated. Analysis of results in subgroups revealed that, in one subgroup (18 patients), the rate of recovered consciousness at 1 month was significantly higher when OHP was used. These patients were under 30 and had a brain stem contusion without supratentorial mass lesion. The view is defended that, besides its toxic action on the normal nervous tissue, OHP can counteract edema and ischemia in the zones of brain injuries.
The authors enrolled 168 patients with closed-head trauma into a prospective trial to evaluate the effect of hyperbaric oxygen in the treatment of brain injury. Patients were included if they had a total Glasgow Coma Scale (GCS) score of 9 or less for at least 6 hours. After the GCS score was established and consent obtained, the patient was randomly assigned, stratified by GCS score and age, to either a treatment or a control group. Hyperbaric oxygen was administered to the treatment group in a monoplace chamber every 8 hours for 1 hour at 1.5 atm absolute; this treatment course continued for 2 weeks or until the patient was either brain dead or awake. An average of 21 treatments per patient was given. Outcome was assessed by blinded independent examiners. The entire group of 168 patients was followed for 12 months, with two patients lost to follow-up study. The mortality rate was 17% for the 84 hyperbaric oxygen-treated patients and 32% for the 82 control patients (chi-squared test, 1 df, p = 0.037). Among the 80 patients with an initial GCS score of 4, 5, or 6, the mortality rate was 17% for the hyperbaric oxygen-treated group and 42% for the controls (chi-squared test, 1 df, p = 0.04). Analysis of the 87 patients with peak intracranial pressures (ICP) greater than 20 mm Hg revealed a 21 % mortality rate for the hyperbaric oxygen-treated patients, as opposed to 48% for the control group (chi-squared test, 1 df, p = 0.02). Myringotomy to reduce pain during hyperbaric oxygen treatment helped to reduce ICP. Analysis of the outcome of survivors reveals that hyperbaric oxygen treatment did not increase the number of patients in the favorable outcome categories (good recovery and moderate disability). The possibility that a different hyperbaric oxygen treatment paradigm or the addition of other agents, such as a 21-aminosteroid, may improve quality of survival is being explored.
While no research study has yet demonstrated convincing evidence for the efficacy of Hyperbaric Oxygen Therapy (HBOT) in patients with chronic neurological disorders (CND), anecdotal studies have been supportive of its use in improving healing of the damaged brain. The current study hypothesized that (1) individuals with CND show increases in cerebral blood flow and metabolism as measured by Single Positron Emission Computed Tomography (SPECT) in the cerebral hemispheres, but not on measures of cerebellar and pons blood flow; and (2) younger patients show more improvement than older patients. The study used archival data to compare 25 older and 25 younger subjects who were given SPECT scans pretherapy, midtherapy, and posttherapy. ANOVAs using the SPECT scans as a within subjects variable and age as a between subjects variable confirmed the hypothesis that the cerebral measures all changed but that the cerebellar and pons measures did not. Post-hoc t-tests confirmed that there was improvement in blood flow from the beginning to the end of the study. An age effect was found on only two of the five measures; however, there were no interactions. Analysis by post-hoc t-tests showed that the younger group had higher blood flows, but not more improvement than the older group. The results provided the first statistical research data to show the effectiveness of HBOT in improving blood flow in CND. These results indicate that HBOT can be an effective part of the treatment for such clients. The implications of these findings and future research directions were discussed.
To identify the benefits and harms of hyperbaric oxygen therapy (HBOT) to treat traumatic brain injury (TBI). MEDLINE, EMBASE, the Cochrane Library, HealthSTAR, CINAHL, MANTIS, professional society databases, and reference lists. Databases were searched from inception through December 2003. We included English-language studies of patients with TBI given HBOT and evaluating functional health outcomes. Data were abstracted by 1 reviewer and checked by a second. Study quality was rated as good, fair, or poor. Two fair-quality randomized controlled trials of patients with severe brain injury reported conflicting results. One found no difference in mortality (48% HBOT vs 55% control) or morbidity at 1 year. In young patients with brainstem contusion, significantly more regained consciousness at 1 month with HBOT (67%) than control (11%) (P<.03). The other found a significant decrease in mortality in the HBOT group at 1 year (17%) compared with controls (31%) (P=.037). This decrease in mortality was accompanied by an increase in proportion of patients with severe disability. Patients with intracranial pressure (ICP) greater than 20 mmHg or a Glasgow Coma Scale score of 4 to 6 had significantly lower mortality at 1 year than controls. Five observational studies did not provide better evidence of effectiveness or adverse events. Two indicated a potential for initially reducing elevated ICP in some patients. However, rebound elevations higher than pretreatment levels occurred in some patients. Adverse events, including seizures, pulmonary symptoms, and neurologic deterioration, were reported; however, no study systematically assessed adverse events, and none reported adverse events in control groups. The evidence for HBOT for TBI is insufficient to prove effectiveness or ineffectiveness, and more high-quality studies are needed. The evidence indicates that there is a small chance of a mortality benefit, which may depend on subgroup selection. The effect on functional status and the incidence and clinical significance of adverse effects are unclear.
Traumatic brain injury is common and presents a health problem with significant effect on quality of life. Hyperbaric oxygen therapy (HBOT) has been suggested to improve oxygen supply to the injured brain and, therefore, to reduce the volume of brain that will ultimately perish. It is postulated that the addition of HBOT to the standard intensive care regimen may result in a reduction in patient death and disability as a result of these additional brain-preserving effects. To assess the benefits and harms of adjunctive HBOT for treating traumatic brain injury. We searched CENTRAL (The Cochrane Library Issue 4, 2003), MEDLINE (1966 - 2003), EMBASE (1974 - 2003), CINAHL (1982 - 2003), DORCTHIM (1996 - 2003), and reference lists of articles. Relevant journals were handsearched and researchers in the field were contacted. Randomised studies comparing the effect on traumatic brain injury of therapeutic regimens which include HBOT with those that exclude HBOT (with or without sham therapy). Three reviewers independently evaluated the quality of the relevant trials using the validated Oxford-Scale (Jadad 1996) and extracted the data from the included trials. Four trials contributed to this review (382 patients, 199 receiving HBOT and 183 control). There was a trend towards, but no significant increase in, the chance of a favourable outcome when defined as full recovery, Glasgow outcome score 1 or 2, or return to normal activities of daily living (relative risk [RR] for good outcome with HBOT 1.94, 95% confidence interval [CI] 0.92 to 4.08, P=0.08). Pooled data from the three trials with 327 patients that reported mortality, showed a significant reduction in the risk of dying when HBOT was added to the treatment regimen (RR 0.69, 95% CI 0.54 to 0.88, P=0.003). Heterogeneity between studies was low (I(2) =0%), and sensitivity analysis for the allocation of dropouts did not affect that result. This analysis suggests we would have to treat seven patients to avoid one extra death (number needed to treat [NNT] 7, 95% CI 4 to 22). One trial suggested intracranial pressure was favourably lower in those patients receiving HBOT in whom myringotomies had been performed (WMD with myringotomy -8.2 mmHg, 95% CI -14.7 mmHg to -1.7 mmHg, P=0.01), while in two trials there was a reported incidence of 13% for significant pulmonary impairment in the group receiving HBOT versus 0% in the non-HBOT group (P=0.007). In people with traumatic brain injury, the addition of HBOT significantly reduced the risk of death but not of favourable clinical outcome. The routine application of HBOT to these patients cannot be justified from this review. In view of the modest number of patients, methodological shortcomings and poor reporting, this result should be interpreted cautiously, and an appropriately powered trial of high methodological rigour is justified to define those patients (if any) who can be expected to derive most benefit from HBOT.
To investigate the safety and efficacy of hyperbaric oxygen therapy (HBOT) in adult patients with sudden sensorineural hearing loss (SSNHL) who fail standard of care steroid and antiviral therapy. Prospective cohort study. An urban tertiary referral center. Nine adult patients presenting with SSNHL from December 2002 through February 2004. Patients with acute onset SSNHL of greater than 30 dB in three contiguous frequencies who failed to show audiometric improvement after 2 weeks of systemic steroids and antivirals were enrolled. Study patients received HBOT at 2.0 atmospheric pressure for 90 minutes while breathing 100% oxygen under a clear plastic hood in the chamber. Treatments were administered daily for 10 days over a 2-week period. Pre-and postHBOT mean hearing gains measured in decibels for pure-tone audiometry at 0.5, 1, 2, 3, and 4 KHz for bone and additional 8 KHz for air; pure-tone averages for air and bone; speech reception thresholds; and speech discrimination levels. Patient-reported subjective recovery rates (completely, substantially, partially, not improved) were also recorded. Overall, two patients had a dramatic improvement, and one patient had a dramatic improvement in his speech discrimination without improvement in other audiometric measures. Six patients had no demonstrable hearing gains. Two patients had complications of serous otitis media requiring myringotomy and pressure equalizing tube placement. No other complications were observed. Secondary HBOT after failure of systemic steroid and antiviral therapy may be associated with hearing gains in some patients with SSNHL.
Hyperbaric oxygen therapy (HBO2) has been utilized for many years for a multitude of disease entities. One commonly encountered side-effect is otic barotrauma. To determine if patients with specific disease processes are at increased risk of requiring tympanostomy tubes during HBO2. Data was obtained from Jan. 2000 to Dec. 2004, retrospectively. The requirement for tympanostomy tubes during a course of HBO2 was established. 325 met inclusion criteria. Fifteen percent of patients overall (95% CI= 11-19%) required tympanostomy tubes. Tubes were required in: 5% necrotizing soft tissue infection (p=0.33); 10% failed/threatened graft (p=0.39); 15% problem wounds; 17% chronic refractory osteomyelitis (CRO) (p=0.64); 22% soft tissue radionecrosis (STRN)/osteoradionecrosis (ORN) (p=0.02); 33% of crush injuries (p=0.10). Twenty-nine percent of nasopharyngeal radiation injury patients (p=0.001) and 10% of the non-nasopharyngeal radiation patients (p=0.36) received tympanostomy tubes. A significant increase in tympanostomy tubes were required in nasopharyngeal radiation injury patients.
Recently, the effect of hyperbaric oxygen (HBO(2)) therapy was explored in the treatment of chronic TBI. It has been speculated that idling neurons in the penumbra zone remain viable several years after injury and might be reactivated by enhanced oxygenation. We studied the therapeutic potential of HBO(2) therapy in a 54-year-old man who had sustained traumatic brain injuries one year before testing that resulted in permanent neurological symptoms. Two treatment series separated by a one-year inter-session interval were administered. Treatment series consisted of 20 and 60 daily one-hour exposures to 100% oxygen at 2 ATA. Electrophysiological (event-related potentials), metabolic and behavioral (sensorimotor and neuropsychological) measurements were obtained to evaluate the effects of hyperbaric oxygen therapy on neurocognitive functioning. Following the initial treatment, the patient showed improvements in sensorimotor functions, as well as enhanced P300 amplitude in the damaged hemisphere. Although most of these gains were no longer observed one year after treatment, these were reinstated with an additional series of 60 exposures. Neuropsychological improvements were also observed after the completion of the second series of treatments. The present single-case study provides preliminary evidence of neuropsychological and electrophysiological improvements after series of 20 and 60 treatments, although the first dosage appeared to be insufficient to produce permanent benefits. Longitudinal studies using different treatment parameters should be conducted if we are to systematically investigate long-term improvements resulting from HBO(2) therapy.