Side effects of hyperbaric oxygen therapy in children with cerebral palsy.

BACKGROUND: This article reports the side effects observed in a double-blind placebo-controlled multi-center randomized clinical trial carried out to assess the efficacy and safety of hyperbaric oxygen (HBO2) therapy in children with cerebral palsy. Intention-to-treat analysis did not prove to have a beneficial effect. MATERIAL AND METHODS: 111 children aged 3 to 12 years were included and followed for 8 weeks. They all received 40 compressions of 1 hour (5 days per week). In the treated group (n=57), HBO2 sessions consisted of an exposure to 100% oxygen at 1.75 atmosphere absolute (atm abs) while children in the control group (n=54) received air at 1.3 atm abs. A physician carried out a general health surveillance including an ear examination prior to and immediately following each session. All clinical events occurring during the course of the study were recorded. FINDINGS: Events were classified in 3 categories: Events related to pressure/volume changes, events related to oxygen toxicity, and other events. No events due to oxygen toxicity were noted. Only middle ear barotrauma significantly differed according to the groups (50% in HBO2 session group versus 27.8% in control group). Other events were rare and equivalent in both groups. CONCLUSION: Short-term exposure to HBO2 at medium level pressure (1.75 atm abs) was responsible for a significant increase of middle ear barotrauma compared to children that received very low external pressure (1.3 atm abs).     

A prospective, randomized clinical trial comparing two hyperbaric treatment protocols for carbon monoxide poisoning.

INTRODUCTION: The optimal hyperbaric oxygen (HBO2) treatment protocol for acute carbon monoxide (CO) poisoning is unknown. This is indicated by one study that found 18 different protocols to treat CO poisoning by North American multiplace hyperbaric facilities. A pilot study was conducted to evaluate the feasibility of randomizing patients to different protocols and to determine whether any large differences in clinical outcome were present between the two most common protocols. METHODS: Adult patients with accidental CO poisoning resulting in transient loss of consciousness, presentation to the emergency department within 12 hours, primary language English, high school education, and residence within 100 miles of the hyperbaric facility were recruited. Enrolled patients were randomized to one HBO2 treatment at 2.4 atmospheres absolute (atm abs) pressure with 90 minutes of 100% oxygen breathing vs. treatment by the US Air Force CO protocol (3.0 atm abs maximum pressure). A neurocognitive screening test was performed immediately after hyperbaric treatment and repeated 14-21 days later. RESULTS: From 1995 to 2002, 30 patients age 21 to 88 years were randomized, 18 to treatment at 2.4 atm abs and 12 to 3.0 atm abs. Average carboxyhemoglobin level for the population was 24.8 +/- 8.8% (mean +/- SD). Delay to hyperbaric treatment averaged 313 +/- 129 minutes. Neither variable was different between treatment groups. Six patients had abnormal neurocognitive testing immediately following hyperbaric treatment, 4 in the 2.4 atm abs group (22%) and 2 in the 3.0 atm abs group (17%) (P=0.71). One patient in each group demonstrated abnormality on delayed testing (p=0.75). One in each group did not return for follow-up. CONCLUSIONS: It is feasible to randomize CO-poisoned patients to different hyperbaric treatment protocols. Determination of differences in efficacy between treatment protocols will require a large multicenter trial with the use of detailed neurocognitive testing.     

Hypoxemia with air breathing periods in U.S. NAVY Treatment Table 6.

Air breathing is used to lessen hyperbaric oxygen (HBO2) toxicity. Hypoxemia could occur during hyperbaric air breathing in patients with lung dysfunction, although this has not been previously reported. We report two cases of hypoxemia during air breathing with two patients treated with the US Navy Table 6. Patient 1 was an 11-year-old male with cerebral gas embolism (during cardiac transplantation), patient 2 was a 66-year-old female with cerebral gas embolism from a central venous catheter accident. Both were mechanically ventilated. We monitored arterial blood gas (ABG) during therapy. In both patients, ABG measurements showed hypoxia during the first air breathing period at 1.9 atm abs (192.5 kPa). If patients require > or = 40% inspired oxygen before HBO2 therapy, oxygenation monitoring is advisable during air breathing periods, especially at lower chamber pressures (< or = 2.0 atm abs).     

Hyperbaric oxygen therapy in two patients with non-arteritic anterior optic neuropathy who did not respond to prednisone

Recent advances in understanding the effects of hyperbaric oxygen (HBO) on retinal anoxia gave rise to new interest in the possibility of using it as therapeutic treatment for ischemic conditions of the retina and optic nerve. Two patients with non-arteritic anterior ischemic optic neuropathy due to a high-grade ophthalmic artery stenosis were treated with HBO at 2 atm abs in an effort to increase oxygen delivery for the eye. Both patients showed marked improvements of visual acuity and visual field 3-5 months following the event. Our results are intriguing although the achieved improvement could be coincidental.     

The effect of hyperbaric oxygen on human oral cancer cells.

Discoveries of the beneficial cellular and biochemical effects have strengthened the rationale for the administration of hyperbaric oxygen therapy (HBO2) as an adjunctive therapy for the treatment of osteoradionecrosis (ORN). Malignancies, however, are considered a contraindication for HBO2 because of the possible tumor-promoting effects. The aim of this study was to examine the effects of HBO2 therapy on tumor weight, and to measure the progression of apoptosis and tumor cell proliferating activity in a cultured human oral cancer cell line. Twenty 5-week-old male NODscid mice underwent daily HBO2 of 2.5 atm abs, 90 minutes for 20 treatments. The control group, n = 20, did not undergo HBO2 and tumor weight, apoptosis index, and proliferating activity parameters were compared between the two groups. The results showed no significant differences (p < 0.05) in the whole-body weights, tumor weights, apoptotic index or proliferating activity index between the two groups. By using the apoptosis and proliferating activity assays which were better indicators of tumor cell growth than tumor weight alone, our results suggest that the clinical application of HBO2 does not promote the growth or proliferation of human oral cancer cells.     

Validation of hyperbaric oxygen treatment software for use with monoplace chambers

Hyperbaric oxygen (HBO2) therapy is increasingly used in the treatment of a wide variety of medical conditions. However, for monoplace chambers, there is some uncertainty when sufficiently high oxygen concentrations are attained, because most chambers are not instrumented to measure oxygen. To remedy this, Microsoft Excel-based software, HBO O2 Smart Guide, was developed to simulate the atmosphere ofmonoplace chambers during treatment. Based upon chamber dimensions, patient weight, oxygen purge rates, desired pressurization, and HBO2 time, the program calculates oxygen concentration, consumption and exposure for each treatment. Software testing was conducted using four different chambers instrumented with an oxygen analyzer. Two purge rate profiles were used: constant, and biphasic (a high initial purge rate was changed to a lower plateau rate when pressurization was reached). Comparison of measured and calculated times to reach 95% oxygen concentration within the chambers demonstrated the software was accurate within 1%. The HBO O2 Smart Guide enables optimum purge profiles to be simulated with resultant potential improvements in HBO2 treatment efficacy, calculation of effective oxygen exposures (actual time during prescribed treatment during which patient breathes > or = 95% oxygen) to enable more accurate comparison of treatment profiles and outcomes, and cost savings in oxygen usage. This software will enable clinicians to provide more consistent HBO2 treatments.     

高压氧治疗急性缺血性脑卒中近期疗效的系统评价

 目的评价高压氧(HBO)治疗急性缺血性脑卒中的近期疗效及安全性.方法使用国际Cochrane协作网的系统评价方法对全世界关于HBO治疗急性缺血性脑卒中的随机/半随机对照试验进行系统评价.结果至2001年12月,共收集到国内外23个已完成的RCTs,其中18个(共包括2 040例患者)试验,符合本研究的纳入标准.早期病死率降低(0 vs11.11%;OR 0.12;95%CI0.02～0.90;P<0.05),提示用HBO每治疗9人可避免约1人早期死亡;HBO治疗的副作用明显高于对照组(2.82%vs0;OR 5.54;95%CI 2.09～14.68;P<0.01);HBO治疗期末神经功能缺损改善的人数显著增加(94.88%vs79.18%:OR4.37;95%CI 3.30～5.77;P<0.01).结论HBO治疗急性缺血性脑卒中是一种有前途的治疗方法,但由于存在发表偏倚及RCTs普遍质量较低尚不能对HBO的疗效作出明确的结论,潜在的疗效及安全性有待于更多的设计严格的RCTs予以进一步证实.     

核因子-κB在大鼠肺型氧中毒发病中的作用

目的 探讨核因子(NF)-κB在大鼠肺型氧中毒发病中的作用.方法 32只SD大鼠随机分为正常对照组及230 kPa高压氧暴露2、6、10 h组.观察肺组织病理变化以及NF-κB和肿瘤坏死因子a(TNF-α)在肺组织中含量的变化.结果 (1)病理检查发现肺组织在高压氧暴露6 h组出现炎症改变,10 h组肺损伤加重.(2)肺组织细胞核中NF-κB P65含量在高压氧暴露2 h组中明显增高,6 h组中达高峰,10 h组中下降但仍高于正常对照组.(3)肺组织TNF-α mRNA表达及肺匀浆中TNF-α浓度在高压氧暴露6 h组中明显增高,10 h组中继续增高.结论 高压氧可以通过活化NF-κB诱导TNF-α高表达从而介导氧中毒的肺损伤.     

高压氧治疗对严重烧伤大鼠肠黏膜屏障作用的影响

目的 探讨高压氧治疗对严重烧伤大鼠肠黏膜屏障作用的影响。方法 健康成年雄性SD大鼠45只,采用数字表法,随机分为假烫组(n=16)、烧伤组(n=14)和烧伤+HBO治疗组(n=15)。采用大鼠背部30％ TBSAⅢ度烫伤模型,高压氧治疗组在烧伤后24h始,在高压氧舱0.15 MPa( 1.5ATA)压力下,每日吸入95％以上浓度的氧气1h,连续5d。各组大鼠于伤后第7天取肠黏膜组织血及下腔静脉,观察各组肠黏膜组织病理变化差别,测血浆二胺氧化酶(DAO)、D-乳酸等指标。结果 与假烫组相比,烧伤组肠黏膜出现明显病理改变,而应用高压氧治疗后,肠黏膜损伤明显减轻。烧伤后第7天大鼠血浆DAO和D-乳酸水平明显增高,而应用高压氧治疗后,上述两指标水平明显下降。结论 高压氧治疗能够对严重烧伤大鼠肠黏膜屏障起到保护作用。     

Hyperbaric oxygen therapy for idiopathic sudden sensorineural hearing loss

Idiopathic sudden sensorineural hearing loss (ISSHL) is the newest indication approved by the Undersea and Hyperbaric Medical Society's Hyperbaric Oxygen Therapy Committee. Idiopathic sudden sensorineural hearing loss appears to be characterized by hypoxia in the perilymph and therefore the scala tympani and the organ of Corti. A review of the literature reveals more than 100 publications evaluating the use of hyperbaric oxygen (HBO2) for the treatment of ISSHL, including eight randomized controlled trials. The best and most consistent results are obtained when HBO2 is initiated within two weeks of symptom onset and combined with corticosteroid treatment. The average hearing gain is 19.3 dB for moderate hearing loss and 37.7 dB for severe cases. This improvement brings hearing deficits from the moderate/severe range into the slight/no impairment range. This is a significant gain that can markedly improve a patient's quality of life, both clinically and functionally.     

高压氧反复暴露对小鼠淋巴细胞免疫粘附功能的影响

目的　探讨高压氧 ( HBO)不同暴露次数对小鼠淋巴细胞免疫粘附功能的影响。方法　小鼠暴露于 0 .2 5 MPa( 2 .5 ATA) 99.2 % O2 的 HBO下 ,每日暴露 2 h,连续暴露 1,3,5 ,10 ,15 ,2 0 d,测定脾脏和胸腺中淋巴细胞免疫粘附肿瘤细胞的能力及其脂质过氧化物的降解产物丙二醛 ( MDA)含量。结果　在 HBO暴露早期 ,淋巴细胞免疫粘附功能下降 ,随暴露次数增多 ,脂质过氧化程度减轻 ,淋巴细胞免疫功能不同程度回升。结论　高压氧暴露产生的氧自由基参与了机体免疫器官的损伤 ,这种损伤作用与暴露次数有关     

Reduced nitric oxide concentration in exhaled gas after exposure to hyperbaric hyperoxia.

The objective of this study was to evaluate exhaled nitric oxide concentration (FENO) and exhaled breath condensate (EBC) pH and H2O2 as biochemical markers of pulmonary oxygen toxicity in association with hyperbaric oxygen (HBO2) therapy. FENO, EBC pH and H2O2 were measured during the course of a 4 week HBO, treatment period, and the responses to a single HBO2 exposure at the start and end of the treatment period were assessed. The HBO2 exposure was at a pressure of 240 kPa for 90 min 5 days a week for 4 weeks. Eight patients undergoing HBO2 therapy and eight control subjects participated in the study. There was a reduction in FENO immediately after HBO2 exposure of 33.1 (SD = 7.8) % on Day 1 and 40.7 (SD = 8.9) % on Day 25. EBC pH was reduced after the first exposure only. Baseline F(E)NO and EBC pH and H2O2 measured before the HBO2 exposures did not change throughout the HBO2 treatment period. A single HBO2 exposure induces a significant transient decrease in FENO. Repeated exposures do not appear to induce inflammatory processes in the lung associated with an increase in FENO.     

Improvement in motor and cognitive impairment after hyperbaric oxygen therapy in a selected group of patients with cerebrovascular disease: a prospective single-blind controlled trial.

BACKGROUND: Clinical and experimental evidence suggests that a localized decrease in oxygen brain tissue availability contributes to the neurological deficit in patients with cerebrovascular disease (CVD) who also present with frontal leukoaraiosis (LA) (periventricular hypodensity on CT scan) and lacunar infarcts. In a prospective controlled trial blinded to patients but not to investigators, we tested the effect of HBO2 on this group of patients. METHODS: Selected patients with symptomatic CVD, LA and lacunar infarcts received daily exposures of 45 minutes for 10 days to hyperbaric oxygen (n=18, HBO2 group) or hyperbaric air (n=8, control group). The control group subsequently received HBO2. Scores of conventional scales for motor and cognitive functions were obtained and videotaped before and after exposure. After the exposures, participants were followed on a monthly basis with systematic clinical neurological examination for up to 6 months. Results. There was a statistically significant improvement in all scales for the HBO2 group compared with the placebo group and in the placebo group after receiving HBO2 (p<0.05). Neurological improvement persisted in the majority of patients for up to 6 months. Repetition of the HBO2 protocol in 9 patients in whom symptoms recurred after 6 months resulted in improvement of symptoms. CONCLUSIONS: These data provide evidence consistent with the notion that HBO2 improves neurological function in patients with CVD, lacunar infarcts and frontal LA. Because of the lack of investigator blinding and a relatively small sample size in this study, larger, randomized controlled studies are needed to further test this hypothesis and to further define the role of oxygen therapy for brain repair in chronic brain disease.     

Effects of hyperbaric oxygen on a human model of injury.

To determine whether intermittent exposures to hyperbaric oxygen enhance recovery from delayed-onset muscle soreness of the quadriceps, we conducted a randomized, controlled, double-blinded, prospective study using 66 untrained men between the ages of 18 and 35 years. After the induction of muscle soreness, these subjects were treated in a hyperbaric chamber over a 5-day period in two phases, with four groups (control, hyperbaric oxygen treatment, delayed treatment, and sham treatment) in the first phase; and three groups (3 days of treatment, 5 days of treatment, and sham treatment) in the second phase. The hyperbaric exposures involved 100% oxygen for 1 hour per day at 2.0 atm. The sham treatments involved 21% oxygen for 1 hour per day at 1.2 atm. We monitored recovery using a leg dynamometer to test eccentric torque of the nondominant quadriceps muscle before and immediately after exercise and at 48 and 96 hours after exercise. Pain was tested daily using visual analog pain scales. In phase 1 a significant difference in recovery of eccentric torque was noted in the treatment group compared with the other groups. In phase 2, the recovery of eccentric torque for the 5-day treatment group was significantly greater than for the sham group from immediately after exercise to 96 hours after exercise. The pain data did not differ significantly in any comparison in either phase. The results suggest that treatment with hyperbaric oxygen may enhance recovery of eccentric torque of the quadriceps muscle from delayed-onset muscle soreness.     

高压氧直接暴露下细胞内Ca2+的变化及其检测

目的 探讨直接暴露高压氧下细胞内Ｃａ＾２＋的变化规律及其相应的检测方法。方法 采用自行研制的微型细胞氧舱,结合显微荧光方法,测定共培养的内皮细胞（ＥＣ）和平滑肌细胞（ＳＭＣ）内钙浓度变化。结果 （１）细胞氧舱密闭性好,体积小,能耐受０．６ＭＰａ的压力,可在高压氧暴露下直接观测细胞钙变化。透光强度,图像不失真。（２）０．２和０．３ＭＰａ高压氧暴露下初始阶段５ｍｉｎ以内ＥＣ［Ｃａ＾２＋］ｉ和ＳＭＣ［Ｃ     

早期不同压力高压氧治疗中重度创伤性脑损伤大鼠的疗效及磁共振变化特点

目的:探讨早期不同压力高压氧(HBO)治疗中重度创伤性脑损伤(TBI)大鼠的疗效及磁共振变化特点。方法:健康清洁级成年雄性SD大鼠60只,采用随机数字表法分为TBI组、假手术组(Sham组,仅将颅骨开窗,不予头部打击)、0.15 MPa HBO组(在TBI组的基础上给予0.15 MPa HBO治疗)、0.25 MPa HBO组(在TBI组的基础上给予0.25 MPa HBO治疗),每组15只。所有大鼠分别在术后第1天(D1)、第3天(D3)、第7天(D7)进行神经功能缺损评分(mNSS);在磁共振DWI图像上显示高信号处取3个感兴趣区(ROI),测量各点表观弥散系数(ADC),比较病变侧与正常对侧ADC的比值,即相对ADC(rADC)。结果:在D1,各组大鼠不同ROI的rADC值比较差异均无统计学意义( P>0.05);在D3,0.15 MPa和0.25 MPa HBO组不同ROI的rADC值均低于TBI组( P<0.05),高于Sham组( P<0.05),0.15 MPa和0.25 MPa HBO组间比较差异无统计学意义( P>0.05);在D7,0.15 MPa和0.25 MPa HBO组rADC值均低于TBI组( P<0.05),与Sham组比较差异无统计学意义( P>0.05),0.15 MPa和0.25 MPa HBO组间比较差异无统计学意义( P>0.05);在D1,TBI组、0.15 MPa和0.25 MPa HBO组大鼠mNSS差异无统计学意义( P>0.05),但均显著高于sham组( P<0.05);在D3,0.15 MPa和0.25 MPa HBO组mNSS均低于TBI组( P<0.05),高于Sham组( P<0.05), 0.15 MPa和0.25 MPa HBO组间比较差异无统计学意义( P>0.05);在D7,0.15 MPa和0.25 MPa HBO组mNSS均低于TBI组( P<0.05),略高于Sham组( P>0.05)。 结论:早期HBO治疗中重型TBI大鼠疗效确切,但HBO的治疗压力可能不是决定预后的关键环节。     

Hyperbaric oxygenation therapy enhances the protective effect of moderate hypothermia against forebrain ischemia in the gerbil hippocampus.

Moderate hypothermia may have a beneficial effect on the neurological outcome. However, ischemic deterioration such as brain swelling during rewarming has been reported as a notable complication after successful therapeutic cerebral hypothermia. In this study, we investigated the effects of hyperbaric oxygenation during rewarming. Forebrain ischemia was produced in 24 gerbils and sham ischemia in 8 animals. Then ischemia-treated animals were divided into 3 groups, whole-body moderate hypothermia (31 degrees C for 60 min) and hyperbaric oxygenation (HBO2) (2- atmosphere absolute for 60 min using 100% oxygen) during rewarming group (n = 8), moderate hypothermia without HBO2 group (n = 8), and sham treatment without hypothermia and without HBO2 group (n = 8). Both the hypothermia group (77.9 +/- 48.1 neurons per mm, mean +/- SD) and hypothermia + HBO2 group (127.6 +/- 29.7 neurons per mm,) showed significant preservation of CA1 pyramidal neurons in the hippocampus compared to that in the sham treatment group (6.4 +/- 2.7) (p < 0.01). Furthermore, the hypothermia + HBO2 group showed significantly greater preservation of CA1 pyramidal neurons than the hypothermia group (p < 0.05). These results suggest that HBO2 during rewarming preserves the protective effect of hypothermia against ischemic neuronal damage.     

A systematic review of the application of hyperbaric oxygen in the treatment of severe anemia: an evidence-based approach.

The treatment of severe anemia with hyperbaric oxygen (HBO2) is one of thirteen indications approved by the Hyperbaric Oxygen Therapy Committee of the Undersea and Hyperbaric Medical Society for appropriate use of the therapy (1). This paper systematically reviews the literature reporting the use of HBO2 therapy in the treatment and management of severe anemia. Increasingly, a trend to use standards of evidence-based medicine to evaluate the effectiveness of therapeutic interventions in injury and illness is productively with us in medicine today. At issue is discovery and evaluation of the best evidence available in world medical literature for evaluation of current treatment of the individual patient. The best evidence is a published randomized controlled prospective human trial; at the other end of the spectrum, the least valued evidence is a published expert opinion. In this review thirty-five publications have been reviewed as representing published results of applying HBO2 in treatment of severe anemia. Each article underwent the evidence-based evaluative grading of the American Heart Association system (AHA), the National Cancer Institute Patient Data Query system (NCI-PDQ), and the British Medical Journal's (BMJ) Clinical Evidence system. Comparative results using the three systems of evaluation are presented in tabular form for the reader. All publications report a positive result when HBO2 is delivered as treatment for severe anemia. Other alternatives other than transfusion with autologous or heterologous matched blood products are helpful but most too have not been the subject of prospective human randomized controlled trials. HBO2 may be used adjunctively with hematinics, fluorocarbons, and cell wall free polymerized hemoglobin (currently fluorocarbons and cell wall free polymerized hemoglobin are not available for routine use in the United States, but both are undergoing advanced stage clinical trials at the time of this review).     

Oxidative stress levels in rats following exposure to oxygen at 3 atm for 0-120 min

BACKGROUND: Hyperbaric oxygen (HBO) is known to cause oxidative stress in several organs and tissues. We previously defined the pressure-related oxidative effects of HBO in several tissues of rats. This study was performed to elucidate the relationship of HBO exposure time to its oxidative effects. METHODS: A total of 49 rats were randomly divided into 5 groups. Study groups were subjected to 3 atm HBO for 30, 60, 90, and 120 min except the control group. Their blood and lungs were removed immediately after exposure and used for analysis. Thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) levels were determined to reflect oxidant and antioxidant status. RESULTS: TBARS levels were found to increase in a time-dependent manner in both erythrocytes [median (min-max); from 0.65 (0.39-0.84) with 30 min HBO exposure up to 1.26 (1.00-1.44) nmol x g(-1) hemoglobin after 120 min] and lung tissue [from 2140 (1550-2510) up to 5465 (5090-5950) nmol x g(-1) protein]. Similarly, SOD activity also presented a dose-dependent course from 0.06 (0.05-0.10) to 0.18 (0.14-0.26) U x g(-1) hemoglobin in erythrocytes and from 16,660 (3479-25,994) to 52,522.5 (41,362-65,799) U x g(-1) protein in lung tissue. In contrast, GSH-Px activity reflected an irregular trend; its levels were mostly found to be increased, but they were decreased at one stage (in the erythrocytes of 30-min exposed rats). CONCLUSIONS: The results of this study exhibited a clear relationship of HBO-induced oxidative action to exposure time. This action was most pronounced from 90 to 120 min of exposure.     

高压氧对脑缺血大鼠学习、记忆能力的影响

目的 探讨高压氧治疗对脑缺血后大鼠学习、记忆能力的影响.方法 将38只雄性健康Sprague-Dawley大鼠,采用随机数字表法分为4组,正常对照组10只,假手术组10只,缺血组9只,高压氧组9只.参照Pulsinelli等报道的四血管阻断方法并加以改良,建立脑缺血模型.高压氧组于术后当天行高压氧治疗,连续7 d,1次/d.各组于术后第7天开始行Morris水迷宫实验,连续6 d,比较各组前5 d每天的逃逸潜伏期及第6天穿越平台的次数.结果 (1)前5 d的逃逸潜伏期比较:高压氧组在第3～5天时均小于缺血组(P＜0.01或P＜0.05);高压氧组在第1～5天时与假手术组差异无统计学意义;缺血组在第3～5天时大于假手术组(P＜0.01或P＜0.05);正常对照组在第2～5天时均小于假手术组(P＜0.01或P＜0.05).(2)第6天穿越平台的次数比较:高压氧组大于缺血组(P＜0.05),与假手术组差异无统计学意义;缺血组小于假手术组(P＜0.01);正常对照组大于假手术组(P＜0.01).结论 高压氧治疗对脑缺血后大鼠学习、记忆能力的恢复有改善作用.