The Feasibility of Extracorporeal Membrane Oxygenation in the Variant Airway Problems

Introduction: Extracorporeal membrane oxygenation (ECMO) is widely used to treat respiratory distress during cardiac or respiratory arrest; moreover, its use is being extended to a wide variety of clinical fields. In this study we assess the utility of ECMO in the management of airway obstruction.Patients and Methods: 15 patients underwent ECMO for airway obstruction. We retrospectively analyzed and evaluated the feasibility of ECMO in the treatment of airway problems.Results: Seven patients received ECMO to facilitate respiration and promote stability during trachea surgery. In six cases ECMO ceased immediately following the operation; in the remaining case ECMO cessation was delayed due to post-operative ARDS. In three cases emergency ECMO was used in response to respiratory arrest; two patients died. In five cases ECMO was emergently inserted to prevent death, following airway blockade by massive hemoptysis. One patient was not discharged from the intensive care unit. Another patient was transferred to a general ward but died from other causes.Conclusion: ECMO is useful during anesthesia in patients at high risk of airway blockade, for example due to endobronchial bleeding, and during complex thoracic surgery. ECMO confers a safer environment during airway surgery, and its complication rate is acceptable.     

Hyperbaric oxygen treatment reduced the lung injury of type II decompression sickness

Objective: To detect the ultrastructural changes in rabbits with type II decompression sickness (DCS), and study the therapeutic effects of hyperbaric oxygen (HBO). Methods: Twenty-seven male New Zealand rabbits were randomly divided equally into the DCS group, HBO treatment group and control group. Experimental models of each group were prepared. Lung apex tissues were harvested to prepare paraffin- and EPON812-embedded tissues. Results: In the DCS group, macroscopic and histological examination revealed severe and rapid damage to lung tissue. Ultrastructural examination revealed exudation of red blood cells in the alveolar space. Type I alveolar epithelial cells exhibited retracted cell processes and swollen mitochondria, and type II cells showed highly swollen mitochondria and decrease in cytoplasmic lamellar bodies. Dilatation and congestion of capillary vessels were accompanied by swelling of endothelial cells and incomplete basement membrane. In the HBO treatment group, the findings were somewhat similar to those in the DCS group, but the extent of damage was lesser. Only a small amount of tiny bubbles could be seen in the blood vessels. Type I alveolar epithelia cells and endothelial cells of the capillaries illustrated slight shortening of cells, swollen cytoplasm and decreased cell processes. Type II alveolar epithelial cells showed slight swelling of the mitochondria, decreased vacuolar degeneration of lamellar bodies, and increase in the number of free ribosomes. Conclusions: Our microscopic and ultrastructural findings confirm that the lung is an important organ affected by DCS. We also confirmed that HBO can alleviate DCS-induced pulmonary damage.     

Dynamic changes of cerebral oxygenation measured by brain tissue oxygen pressure and near infrared spectroscopy

Abstract

The aim of this study was to find out whether a correlation exists between changes in brain tissue oxygen pressure (ti-p0₂) and hemoglobin oxygenation (Hb02) measured by near-infrared spectroscopy. We studied 10 patients with severe head injury. A ti-p0₂ monitoring device was introduced in the frontal white matter as soon as possible after administration. Additionally a NIRS sensor Was placed at the forehead. All data were recorded simultaneously. 'Changes of the ti-p0₂ curve were defined as events with the following criteria: > 10% change from the baseline value, > 3 min duration, clearly not an artifact. 137 events were found with a mean change of ti-p0₂ of 8.3 ± 10.2 mmHg. In 77.4% we observed a corresponding change of the Hb02. In 7 patients we found a good correlation (r> 0.7) between change ti-p0₂ and change Hb0₂. In 3 patients the correlation was poor. The reason for poor correlation might be poor signal quality of the NIRS sensor or inhomogenous distribution of ischemic areas in the whole brain. We conclude that under the condition of a stable NIRS signal and a diffuse brain lesion, changes of ti-p0₂ are well reflected by NIRS. [Neural Res 1997; 19: 246-248]     

Hyperbaric oxygen treatment mitigates liver damage in mice with noise exposure

Noise exposure relates to various pathological disorders including liver damage, preventive measures of which are being demanded. Hyperbaric oxygen treatment (HBOT), as a non-invasive procedure, exerts convincing therapeutic potency on multiple liver diseases. The efficacy of HBOT in mitigating noise induced liver damage (NILD) and associated mechanisms would be elucidated here. Mice were subject to broad band noise (20–20k Hz, 90–110 dB) for 5 days by 3 hours/day. HBOT with 2.5 atmosphere absolute (ata) was employed before noise exposure. Morphology of liver tissue was examined by hematoxylin-eosin (HE) staining. Oil Red O (ORO), transferase-mediated dUTP nick end labelling (TUNEL) test and western blot were utilized to detect lipid accumulation, apoptotic cells and protein expression, respectively. Ceramide (Cer) level was assayed by immunohistochemistry (IHC) analysis. With noise exposure, conspicuous structural derangement and lipid deposition occurred in liver tissue of mice, which was alleviated significantly by the application of HBOT. Meanwhile, HBOT reduced the proportion of apoptotic hepatocytes, restraining the superoxide production in noise exposed mice. In view of underlying mechanisms, noise enhanced the acid sphingomyelinase (ASM) protein expression and the Cer generation in liver tissue of mice which was reversed substantially by HBOT. Altogether, HBOT ameliorates the structural and functional derangement of liver by neutralizing the ASM/Cer pathway in noise exposed mice.     

Cerebral and somatic NIRS-determined oxygenation in IUGR preterm infants during transition

Background: Fetal growth restriction (intra-uterine growth restriction [IUGR]) has a considerable impact on perinatal morbidity. Preterm IUGR infants are prone to impaired intestine function. Near-infrared spectroscopy (NIRS) has been used to monitor oxygenation status of the brain and of the intestine.

Patients and methods: We conducted a prospective case–control study at our NICU in 20 preterm infants of whom 10 infants complicated by compared with 10 non-IUGR preterm infants. Splanchnic and cerebral regional oximetry values were measured with NIRS. Three hours of consecutive recordings were performed in the first 24?h of life, T0, and during the transitional period, T1. The cerebral/splanchnic oxygenation ratio, CSOR, (cerebral regional saturations [rScO_2]/splanchnic regional saturations [rSsO₂]) was also calculated.

Results: Both in the IUGR and the non-IUGR infants, at T0 and T1 monitoring time-points, the rSO₂ values were higher in the cerebral district when compared to those of the splanchnic area. Comparison of the NIRS parameters between the IUGR and non-IUGR infants at T0 showed no difference in rScO₂, while rSsO₂ was significantly lower in the IUGR group. At T1, rScO₂ was significantly lower and rSsO₂ higher in the IUGR group.

Conclusions: Cerebral/splanchnic vascular adaptation of IUGR infants to the extra-uterine environment is characterized by a postnatal persistence of the brain sparing effect with reperfusion in the transitional period.     

高压氧治疗急性脑梗死的疗效以及对患者血清血管内皮生长因子、促血管生成素Ⅱ的影响

目的  观察高压氧治疗对急性脑梗死的临床疗效及其血清中血管内皮生长因子（VEGF）、促血管生成素Ⅱ（Ang-2）含量的影响。方法  选取200例急性脑梗死患者随机分为高压氧治疗组（治疗组）114例、非高压氧治疗组（对照组）86例,两组患者均进行30 d治疗。分别比较两组治疗前后神经功能缺损（NIHSS）评分,日常生活活动能力（ADL）评分及血清中Ang-2、VEGF水平的变化。结果  治疗后两组患者临床神经功能缺损程度评分均有所减少,与治疗前比较,两组均在治疗后24 h内评分差异有统计学意义（P <0.05）,治疗组较对照组评分显著减少,且随着时间延长,评分呈时间依赖性降低;治疗后两组患者ADL评分均有所提高,与治疗前比较,两组在治疗后24 h评分差异无统计学意义（P >0.05）,治疗15 d后评分差异有统计学意义（P <0.05）,治疗组较对照组评分显著增高,且随着时间延长,评分呈时间依赖性升高;两组治疗后血清VEGF及Ang-2含量的比治疗前患者血清中VEGF及Ang-2含量均有不同程度增加,治疗组较对照组VEGF及Ang-2含量显著增加,VEGF及Ang-2含量15 d时达到高峰,30 d时有所下降,与治疗前比较,两组在治疗后24 h VEGF及Ang-2含量差异无统计学意义（P >0.05）。治疗15 d后及30 d后VEGF及Ang-2含量差异有统计学意义（P <0.05）。结论  高压氧治疗可调节脑梗死患者血清中Ang-2 、VEGF的含量,改善神经功能缺损及提高日常生活活动能力,值得进一步研究及应用。