节氧吸氧导管在临床中的应用研究

目的:研制一种吸氧导管,解决呼气箱停止给氧以达到节约氧气,提高氧疗的目的.方法:采用自制吸氧导管与普通吸氧导管对比,将48例符合慢性阻塞性肺疾病(COPD)诊断并有氧疗指征患者随机分为A、B两组各24例,并动态观察其PaO2和PaCO2变化.结果:同等流量给氧,PaO2节氧吸氧导管给氧明显高于普通吸氧导管给氧,差异有显著性(P＜0.05);1/2流量节氧吸氧导管给氧与普通鼻导管给全流量氧PaO2比较,无明显差异(P＞0.05);不同吸氧导管给氧两组PaCO2比较无明显差异(P＞0.05).结论:节氧吸氧导管在1/2流量吸氧效果与普通吸氧导管相同,可节约氧气50%左右,氧疗效果明显.     

新型口鼻面罩用于慢性阻塞性肺病病人氧疗效果观察

为观察新型口鼻面罩（Ventrui面罩）和双侧鼻导管氧疗效果,对30例慢性阻塞性肺病急性加重期病人吸氧前后动脉血pH值、PaCO2及PaO2进行观察。结果显示：Ventrui面罩吸氧组病人的PaO2上升幅度较大,且迅速,能尽快改善病人的缺氧症状,而不加重二氧化碳潴留,与鼻导管组相比差异有统计学意义（P＜0．01）。建议对慢性阻塞性肺病急性加重期病人使用Ventrui面罩持续吸氧,可迅速改善病人的缺氧症状。     

小青龙汤配合基础治疗对慢性阻塞性肺疾病患者血氧饱和度的影响

目的探讨小青龙汤结合基础治疗对慢性阻塞性肺疾病（COPD）患者血氧饱和度的影响。方法选择COPD急性期患者90例，按照随机数字表法随机分为治疗组和对照组各45例，治疗组患者在抗感染、雾化吸入等基础治疗的同时，每日用小青龙汤1剂水煎服；而对照组仅采用抗感染、雾化吸入等基础治疗。连续治疗2周，以用药前后血气分析的动脉氧分压（PaO2）、动脉二氧化碳分压（PaCO2）评定疗效。结果治疗前两组PaO2、PaCO2无明显差异（P〉0．05）；治疗2周后，两组PaO2明显升高、PaCO2明显降低（P〈0．01）；而治疗组与对照组比较，PaO2升高和PaCO2降低比对照组更明显（P〈0．01）。结论小青龙汤结合基础治疗可达到提高COPD患者血氧饱和度，改善患者缺氧状态的作用。     

The degree of exercise hypoxemia reflects pulmonary artery pressure during early exercise in chronic obstructive pulmonary disease patients

The causes of both exertional pulmonary hypertension and pulmonary hypertension in general in chronic obstructive pulmonary disease (COPD) remain to be elucidated. To further understand the pathophysiology in COPD patients, it may be important to recognize the existence of exertional pulmonary hypertension and to determine the severity of exertional hypoxemia. However, little is known about their relationship. To investigate whether the severity of exertional hypoxemia, as evaluated by the Deltaartery oxygen tension/Deltaoxygen consumption (PaO(2)-slope) correlates with the mean pulmonary artery pressure (Ppa), cardiopulmonary exercise testing with haemodynamics was done in 10 patients with moderate to very severe COPD. The PaO(2)-slope was significantly correlated with the mean Ppa from 25% to 40% of the maximum Watts (Wmax), and was most significant at 30% Wmax (r = -0.904, P<0.0001). In this phase, all parameters, except for the mean Ppa and the mixed venous oxygen tension, were not markedly changed from resting levels. At 30% Wmax, the mean Ppa (mean, 27 mmHg) with no or mild hypoxemia was also significantly correlated with the Deltaartery oxygen saturation/Deltaoxygen consumption (SpO(2)-slope) (r = -0.789, P = 0.004). On stepwise multiple regression analysis, the PaO(2)-slope was the most significant predictor of mean Ppa at 30% Wmax. In conclusion, the PaO(2)-slope and the SpO(2)-slope reflect Ppa during the early exercise phase. Thus, assessment of these parameters could be useful to evaluate the cardiopulmonary haemodynamic pathophysiology of COPD patients.     

Redox status of cytochrome a,a3: a noninvasive indicator of dysoxia in regional hypoxic or ischemic hypoxia

OBJECTIVE: Multiwavelength near infrared (NIR) spectrophotometry can monitor the redox state of cytochrome a,a3 (cyt a,a3) in vivo. Because cyt a,a3 is the most immediate reductant of oxygen, this technique has been proposed to evaluate tissue oxygenation. The purpose of this study was to examine the relationship between cyt a,a3 oxidation level as an indicator of dysoxia and oxygen uptake (VO2) when oxygen delivery (DO2) was progressively lowered in an in situ vascularly isolated hindlimb. DESIGN: Prospective, randomized, laboratory study. SETTING: University research laboratory. SUBJECTS: Fourteen pigs. INTERVENTIONS: Measurement of critical values for both VO2 and cyt a,a3 oxidation during ischemic and hypoxic hypoxia. MEASUREMENTS AND MAIN RESULTS: The right hindlimb of anesthetized, paralyzed, and ventilated pigs was subjected to progressive ischemic or hypoxic hypoxia for 100 mins by ten stepwise decreases in DO2. In ischemic hypoxia (n = 7), arterial inflow (Q) from a pump-membrane oxygenator system was lowered from 50 to 0 mL/min, with PaO2 maintained at 100 mm Hg. In hypoxic hypoxia (n = 6), PaO2 was lowered from 100 mm Hg to 0 mm Hg. Hindlimb DO2 was calculated as the product of Q and arterial oxygen content, and VO2 as the product of Q and arteriovenous difference. The cyt a,a3 oxidation level was measured every 10 secs with a four-wavelength spectrophotometer. These parameters were measured 9 mins after each change of DO2. Critical values for both VO2 and cyt a,a3 oxidation level as a function of DO2 were determined in each animal by dual linear regression analysis. In ischemic and hypoxic hypoxia, a strong correlation was found between cyt a,a3 oxidation level and VO2 in both ischemic and hypoxic hypoxia (r2 =.90 and .87, respectively). Hindlimb vascular resistance increased in ischemic hypoxia and decreased in hypoxic hypoxia when DO2 reached critical DO2. CONCLUSIONS: From these results, we concluded that monitoring the cyt a,a3 redox state by NIR spectrophotometry is, in this experimental setting, a sensitive indicator of dysoxia during regional hypoxic or ischemic hypoxia.     

两种氧气雾化吸入器用于高龄COPD患者效果观察

目的 探讨两种氧气雾化吸入器应用于高龄慢性阻塞性肺疾病(chronic obstructive pulmonary disease,COPD)患者的效果.方法 将104例76～104岁的高龄COPD患者分为面罩组(n=48)和喷嘴组(n=56),分别使用面罩氧气雾化器和口含喷嘴氯气雾化器进行氧气雾化吸入,比较两组治疗前后和治疗中生命体征、SpO2、吸入过程配合和不良反应、症状缓解等方面情况.结果 两组患者完成吸入治疗后,面罩组患者SpO2高于喷嘴组(P<0.05);与喷嘴组相比,面罩组患者对正确吸入方法的掌握度较好,症状缓解率更高(P<0.05);两组患者吸入过程不良反应发生情况差异无统计学意义(P>0.05).结论 面罩氧气雾化吸入方式由于吸入方法容易掌握,有利于症状缓解,因此更适合高龄COPD患者.     

气道灌洗治疗吸入性损伤患者的效果观察及护理

目的探讨气道灌洗治疗吸入性损伤患者的效果。方法将60例吸入性损伤患者分为研究组和对照组,每组各30例,对照组采用传统护理方法,包括吸痰、雾化吸入、叩背等,研究组在此基础上采用气道灌洗,观察两组患者血气分析结果和痰痂堵管及肺部感染发生情况。结果研究组患者肺通气功能优于对照组;痰痂堵管率和肺部感染率低于对照组,两组比较,差异均有统计学意义(P0.05)。结论气道灌洗可及时清除吸入性损伤患者气道内痰痂,改善肺通气功能,降低肺部感染发生率。     

Effect of nebulized furosemide in terminally ill cancer patients with dyspnea

We evaluated the effect of ultrasonically nebulized furosemide (20 mg) on dyspnea uncontrollable by standard therapy in patients with terminal cancer. Dyspnea was evaluated using the Cancer Dyspnea Scale (CDS) before and 60 min after inhalation. Changes in arterial blood gases, hemoglobin oxygen saturation (SpO2), heart rate (HR), and respiratory rate (RR) also were evaluated. In 12 of 15 patients (80%), total dyspnea scores by CDS improved significantly after inhalation of furosemide (P = 0.007), especially concerning a reduced sense of effort (P = 0.013) and reduced anxiety (P = 0.04). No significant changes were observed in the partial pressure of oxygen in arterial blood (PaO2), the partial pressure of carbon dioxide in arterial blood (PaCO2), SpO2, HR, or RR. Inhalation of nebulized furosemide appears to be effective against dyspnea in terminally ill cancer patients.     

Oxygen supplementation increases glucose tolerance during euglycaemic hyperinsulinaemic glucose clamp procedure in patients with severe COPD and chronic hypoxaemia

Investigations in chronic obstructive pulmonary disease (COPD) patients have shown impaired glucose tolerance in hypoxic COPD patients, compared with COPD patients with normal arterial blood gases. In healthy subjects, hypoxaemia or stay at altitude, have been shown to alter glucose metabolism. At altitude the effect seems to be dependent on duration of stay. A short stay is associated with insulin resistance, a longer stay gives rise to increased glucose uptake. The euglycaemic hyperinsulinaemic glucose clamp technique is a method to study glucose tolerance and enables determinations of glucose clearance in peripheral tissues. We investigated six COPD patients [forced expiratory volume in 1 s 0.7 +/- 0.2 l (mean +/- SD)] with chronic hypoxaemia (PaO(2) 7.9 +/- 0.6 kPa at rest, breathing air), with and without oxygen supplementation, using the glucose clamp technique. Net peripheral glucose uptake was 5.5 +/- 1.2 and 7.1 +/- 1.6 mg (kg*min)(-1) (+29%) breathing air and supplemental oxygen, respectively (P = 0.03). The tissue sensitivity to insulin increased 32% (P = 0.03) with oxygen supplementation. The results indicate that normalization of oxygen saturation in COPD patients with chronic hypoxaemia may have an immediate effect on glucose tolerance and tissue sensitivity to insulin in these patients.     

高原地区肺心病患者血清碱性成纤维细胞生长因子水平与肺动脉压的关系

目的探讨血清碱性成纤维细胞生长因子(bFGF)在低氧性肺动脉高压发病中的作用。方法采用双抗体夹心酶联免疫吸附法(ELISA)检测高原地区(海拔2260~3300m)38例慢性肺源性心脏病(肺心病)急性加重期患者、30例慢性阻塞性肺疾病(COPD)缓解期患者和30例当地健康人血清bFGF含量,并使用彩色多普勒超声心动仪测定肺动脉血流频谱,计算平均肺动脉压(MPAP),使用血气分析仪测定动脉血氧分压(PaO2)。结果肺心病组血清bFGF(87.54±12.15)ng/L、MPAP(45.86±5.63)mmHg(1mmHg=0.133kPa)显著高于COPD组分别为(55.72±9.08)ng/L和(22.95±2.56)mmHg,P均<0.01,COPD组显著高于健康对照组分别为(49.83±8.78)ng/L和(20.34±2.23)mmHg,P均<0.05;肺心病组PaO2(38.79±4.56)mmHg显著低于COPD组(58.22±6.18)mmHg,P<0.01,COPD组则显著低于健康对照组(66.57±5.48)mmHg,P<0.01。肺心病组和COPD组血清bFGF水平与MPAP均呈显著正相关(r肺心病=0.788,rCOPD=0.674,P均<0.01),与PaO2均呈显著负相关(r肺心病=-0.735,rCOPD=-0.587,P均<0.01)。结论慢性肺心病患者血清bFGF水平明显升高,可能与其慢性低氧性肺动脉高压形成有一定关系。     

Physiological effects of constant versus decelerating inflation flow in patients with chronic obstructive pulmonary disease under controlled mechanical ventilation

OBJECTIVE: To study the cardiorespiratory effects of inspiratory flow rate and waveform in COPD patients. DESIGN: Prospective physiological investigation with randomized allocations of experimental conditions. SETTING: A 14-bed medical ICU in a 1000-bed university hospital. PATIENTS AND PARTICIPANTS: Ten COPD intubated, sedated and paralyzed patients with chronic obstructive pulmonary disease (COPD), mechanically ventilated for acute respiratory failure. INTERVENTIONS: In volume-controlled mode, three inflation flow rates of 0.40, 0.70, and 1.10 l/s for 20 min with a constant (CF) or a decelerating (DF) inflation flow profile. Each patient received all six experimental conditions in a random order. Tidal volume and respiratory frequency were similar during the experimental conditions. MEASUREMENTS AND RESULTS: Arterial blood gases, hemodynamics ( n=8), and respiratory mechanics were measured with zero end expiratory pressure. Between flow rates the median (25th-75th percentiles) values of PaO(2)/FIO(2) were 232 (132-289), 253 (161-338), 231 (163-352) for CF and 253 (143-331), 249 (164-360), 231 mmHg (187-351), for DF, respectively; the maximal airway pressures were 25.6, 28.3, 34.6 cmH(2)O for CF and 21.7, 29.6, 34.8 cmH(2)O for DF, respectively, the mean airway pressures were 8.9, 6.1, 5.4 cmH(2)O for CF and 9.1, 7, 6.5 cmH(2)O for DF, respectively. CONCLUSIONS: Changing the ventilator in volume-controlled mode with a DF or CF profile has no significant cardiorespiratory effect in intubated COPD patients mechanically ventilated for acute respiratory failure.     

Small intestine intramucosal PCO(2) and microvascular blood flow during hypoxic and ischemic hypoxia

OBJECTIVE: To determine whether small intestine intramucosal PCO(2) and mucosal blood flow changes would be different between ischemic and hypoxic hypoxia. DESIGN: Randomized animal experiment. SETTING: Research laboratory. SUBJECTS: Anesthetized, mechanically ventilated, and surgically instrumented pigs. INTERVENTIONS: Systemic oxygen delivery was lowered in a stepwise manner to decrease it beyond critical oxygen delivery by lowering either FIO(2) or blood volume. MEASUREMENTS AND MAIN RESULTS: In hypoxic hypoxia pigs (n = 6), arterial oxygen concentration and oxygen delivery decreases were achieved by progressively reducing arterial PO(2) while cardiac index remained unchanged. In ischemic hypoxia pigs (n = 5), oxygen delivery reduction was achieved by progressively reducing cardiac index while arterial PO(2) remained unchanged. In control pigs, oxygen delivery remained unchanged. The lowest oxygen delivery measured in both hypoxia and ischemia experiments was 3.60 +/- 0.26 vs. 2.93 +/- 0.77 mL x kg(-1) x min(-1), respectively (p =.23). At the lowest oxygen delivery level, differences between ischemic hypoxia and hypoxic hypoxia experiments were observed for arterial lactate concentration (468 +/- 308 vs. 1070 +/- 218 mmol/L, respectively; p =.03), mixed venous arterial PCO(2) difference (10 +/- 7 vs. 4 +/- 2 torr, respectively; p =.04), and small intestine mucosal blood flow (6.2 +/- 2.1 vs. 15.7 +/- 7.4 perfusion units, respectively; p =.02). Small intestine intramucosal-arterial difference was higher in ischemic hypoxia than in hypoxic hypoxia (52 +/- 15 vs. 31 +/- 12 torr, respectively; p =.03). CONCLUSION: Small intestine intramucosal PCO(2) increases may indicate systemic oxygen uptake supply limitation in ischemic and hypoxic hypoxia related to conditions of mucosal flow stagnation and CO(2) generation.     

Home oxygen therapy

Oxygen therapy is one of the principal non-pharmacologic treatments for severe chronic obstructive pulmonary disease (COPD) patients. Home oxygen therapy(HOT), or long-term oxygen therapy(LTOT) for 15 hours or more per day, can improve the survival rate of severe COPD patients with beneficial effects on hemodynamic state, hematological characteristic, exercise capacity, lung mechanics, and mental state. Oxygen therapy is indicated in cases of severe chronic respiratory failure with PaO2 of 55 Torr or less, or in cases with PaO2 of 60 Torr or less in whom there is remarkable hypoxia during sleep or during exercise. The induction of oxygen therapy needs evaluations of oxygen desaturation during exercise and sleep as well as hypoxia at rest. It also required to consider CO2 narcosis.     

延长吸氧时间对改善二氧化碳气腹腹腔镜胆囊切除术后肩部疼痛效果的临床研究

目的:探讨延长吸氧时间对改善二氧化碳气腹腹腔镜胆囊切除术(LC)后肩部疼痛的效果。方法:176例LC患者,随机分为延长吸氧组(n=88),常规吸氧组(n=88),常规吸氧组施行LC后持续低流量(2 L/min)吸氧2 h,延长吸氧组施行LC后持续低流量(2 L/min)吸氧8~12 h。观察两组间LC术后肩部疼痛发生率和疼痛程度。结果:延长吸氧组肩部疼痛发生率明显降低(P=0.000),术后肩部疼痛VAS评分显著降低(P=0.015);血气分析指标的比较,延长吸氧组手术后PaCO2(P=0.037),PaO2(P=0.029),pH(P=0.041)等血气指标较常规吸氧组均有差异;手术后4 h PaCO2与相同时点VAS评分呈正相关性,相关系数0.611(P=0.009)。结论:延长吸氧时间能降低LC术后肩部疼痛的发生率,改善LC术后肩部疼痛程度。     

无创机械通气联合雾化吸入治疗老年COPDⅡ型呼吸衰竭临床分析

目的:探讨无创机械通气联合雾化吸入治疗老年COPDⅡ型呼吸衰竭的疗效。方法:在常规治疗基础上采用BiPAP呼吸机联合雾化吸入治疗COPDⅡ型呼吸衰竭40例,观察治疗前后动脉血气中pH值、PaO2、PaCO2的变化。结果:COPDⅡ型呼吸衰竭患者经治疗后,pH、PaO2升高,PaCO2降低,临床疗效明显,与对照组相比有显著差异(P<0.05)。结论:无创机械通气联合雾化吸入治疗老年COPDⅡ型呼吸衰竭好,有临床推广应用价值。     

不同方法雾化吸入对慢性阻塞性肺疾病患者手术后血气分析的影响

目的　探讨氧气驱动雾化吸入和常规超声雾化吸入对慢性阻塞性肺疾病 (COPD)患者手术后血气分析的影响。方法　 80例COPD患者随机分为A组和B组 ,A组患者使用氧气驱动雾化吸入 ,B组患者使用常规超声雾化吸入 ,比较治疗前后患者血气分析指标中动脉血氧分压 (PaO2 )、动脉血二氧化碳分压 (PaCO2 )和血氧饱和度 (SaO2 )的变化。结果　A组患者治疗后血气分析中PaO2 上升和PaCO2 下降较B组患者明显 ,差异有显著性 (P <0 0 5 ) ;B组患者治疗后SaO2 下降较A组患者更明显 ,差异有显著性 (P <0 0 5 )。结论　氧气驱动雾化吸入在COPD患者手术后提高PaO2 和降低PaCO2 潴留方面优于常规超声雾化吸入     

Heart rate response to hypoxic exercise: role of dopamine D2-receptors and effect of oxygen supplementation

This study examined the effects of dopamine D(2)-receptor blockade on the early decrease in maximal heart rate at high altitude (4559 m). We also attempted to clarify the time-dependent component of this reduction and the extent to which it is reversed by oxygen breathing. Twelve subjects performed two consecutive maximal exercise tests, without and with oxygen supplementation respectively, at sea level and after 1, 3 and 5 days at altitude. On each study day, domperidone (30 mg; n=6) or no medication (n=6) was given 1 h before the first exercise session. Compared with sea level, hypoxia progressively decreased the maximal heart rate from day 1 and onwards; also, hypoxia by itself increased plasma noradrenaline levels after maximal exercise. Domperidone further increased maximal noradrenaline concentrations, but had no effect on maximal heart rate. On each study day at altitude, oxygen breathing completely reversed the decrease in maximal heart rate to values not different from those at sea level. In conclusion, dopamine D(2)-receptor blockade with domperidone demonstrates that hypoxic exercise in humans activates D(2)-receptors, resulting in a decrease in circulating levels of noradrenaline. However, dopamine D(2)-receptors are not involved in the hypoxia-induced decrease in the maximal heart rate. These data suggest that receptor uncoupling, and not down-regulation, of cardiac adrenoreceptors, is responsible for the early decrease in heart rate at maximal hypoxic exercise.     

FiO2 and positive end-expiratory pressure as compensation for altitude-induced hypoxemia in an acute respiratory distress syndrome model: implications for air transportation of critically ill patients.

OBJECTIVES: To determine whether increases in FiO2 or positive end-expiratory pressure will compensate for hypoxemia resulting from exposure to 8000 feet (2440 m) of altitude in a model of acute respiratory distress syndrome. DESIGN: Intervention and crossover design. SETTING: Military research altitude chamber. SUBJECTS: Sixteen Yucatan miniature swine (Sus scrofa). INTERVENTIONS: Swine initially were placed on mechanical ventilation (zero positive end-expiratory pressure, 21% FiO2). Twelve animals had moderate to severe acute respiratory distress syndrome (50% to 70% FiO2 at sea level to maintain PaO2 of 50-70 torr [6.65-9.31kPa]) induced by intravenous oleic acid. Four animals were controls (no lung injury). The animals were taken to 8000 feet (2440 m) in an altitude chamber, and then stepwise increases of either 5% FiO2 (six animals) or 2.5 cm H2O positive end-expiratory pressure (six animals) were made until PaO2 values exceeded 75 torr (10.0 kPa). If PaO2 did not reach 75 torr (10.0 kPa), and time permitted, the animal was crossed over to the other group. MEASUREMENTS AND MAIN RESULTS: Arterial blood gases were drawn at baseline (sea level and at altitude) and after every change in ventilator settings. Positive end-expiratory pressure increases from 5 to 12.5 cm H2O were required to bring the PaO2 in the injured pigs to 75 torr (10.0 kPa). FiO2 increases did not achieve a PaO2 of 75 torr (10.0 kPa) for three of six animals despite reaching 100% FiO2. One animal crossed over from Fio2 to positive end-expiratory pressure and achieved a PaO2 of 75 torr (10.0 kPa) with 5 cm H2O of positive end-expiratory pressure. CONCLUSIONS: Fifty percent of the animals with lung injury had altitude-induced hypoxia that was resistant to increases in FiO2. Increases in positive end-expiratory pressure are more reliable than increases in FiO2 for correcting altitude-induced hypoxia in this model of acute respiratory distress syndrome.     

急、慢性缺氧对大鼠微循环白细胞流变性的影响

背景白细胞流变性对微循环血流灌注有明显影响,但缺氧对微循环中白细胞流变性的影响目前研究极少.目的研究急、慢性缺氧对大鼠肠系膜微循环白细胞流变学行为的影响.设计随机对照的实验研究.地点、材料和干预本实验在解放军第三军医大学高原军事医学系全军高原医学重点实验室进行.成年Wistar大鼠,校动物中心提供,按随机抽签法分为对照组、急性缺氧组和慢性缺氧组,低压舱模拟海拔5 000 m连续缺氧2,30 d,复制动物急性和慢性缺氧模型.主要观察指标正常大鼠、急性缺氧大鼠、慢性缺氧大鼠的白细胞滚动速度、沿壁滚动数、黏附数和白细胞-内皮细胞接触时间(leukocyte-endothelium contacttime,TLECT)及动脉血气的比较结果.结果与对照组比较,急、慢性缺氧组动物表现为动脉血氧分压PaO2和血氧饱和度SaO2显著下降(t=3.01～8.30,P＜0.05).对照组白细胞滚动速度(101.41±26.96)μm/s,滚动数(4.27±2.69)个/min,黏附数(1.45±1.21)个/100μm,TLECT(0.91±0.73)s/min;急性缺氧动物白细胞滚动速度(85.44±17.33)μm/s,滚动数(60.00±31.62)个/min,黏附数(26±8.22)个/100μm,TLECT(16.30±4.84)s/min;慢性缺氧白细胞滚动速度(72.40±24.08)μm/s,滚动数(14.43±3.99)个/min,黏附数(3.57±1.27)个/100 μm,TLECT(2.35±0.86)s/min.急性缺氧组白细胞流变学系数与对照组比较,差异有显著性意义(t=2.54～-9.51,P＜0.05);慢性缺氧组白细胞流变学系数与急性缺氧组比较,差异有显著性意义(t=2.26～7.54,P＜0.05).结论急性缺氧引起肠系膜微循环白细胞流变性显著性改变,影响微循环的正常灌流,是导致血管内皮损伤的重要机制;慢性缺氧大鼠微循环白细胞的流变行为有明显不同,这对促进动物习服适应可能有重要作用.急、慢性缺氧下白细胞流变性的显著性差异可能与白细胞功能的改变及局部微环境的变化有关.     

Effects of naloxone and morphine on acute hypoxic survival in mice.

OBJECTIVE: To investigate a role of the opiate system during acute hypoxic hypoxia, the effects of naloxone and morphine on hypoxic survival rate were investigated in awake adult mice. DESIGN: Prospective, randomized, animal trial. SETTING: University research laboratory. SUBJECTS: Male dd-Y mice (n = 864 in experiment I, n = 144 in experiment II, n = 30 in experiment III). INTERVENTIONS: The animals were placed in an airtight plastic chamber into which a continuous flow of 8 L/min 5% oxygen-95% nitrogen was passed. MEASUREMENTS AND MAIN RESULTS: One and 5 mg/kg naloxone had no significant effect on the survival rate of mice subjected to acute hypoxic hypoxia, whereas 10 mg/kg naloxone decreased the survival rate. On the other hand, 2 and 5 mg/kg morphine was shown to have a protective action against acute hypoxic hypoxia. The protective effects of 5 mg/kg morphine against hypoxia was even antagonized by 5 mg/kg naloxone, which did not itself show any significant effect on the survival rate. The oxygen consumption in the morphine-treated (5 mg/kg) mice was significantly (p < .05) lower (87.0% +/- 4.6%; mean +/- SE) than that in the saline-treated animals. CONCLUSIONS: The present study suggests that the endogenous opiate system does not play a significant role on the pathophysiology caused by acute hypoxic hypoxia and that the improved survival of the hypoxic animals by morphine is at least partly attributable to its depressant effect on oxygen consumption.