吸痰对组织氧代谢的影响

研究吸痰对组织氧代谢的影响。方法：观察１４例危重病人吸痰前,吸痰结束时及吸痰后５ｍｉｎ动脉血气和混合静脉血气的变化。结果：与吸痰前相比,吸痰结束时的动脉血氧分压、血氧饱和度,混合静脑海因氧分压,血氧饱和度均显著降低,吸痰结束后５ｍｉｎ,ＳｖＯ３仍未恢复正常。     

过度通气预防低氧和高碳酸血症的临床观察

气管内吸痰是清除呼吸道分泌物的常规操作,但吸引可导致低氧血症和高碳酸血症。Ｓｔｏｎｅ［１］发现,吸痰期间动脉血氧饱和度降低２５％～３０％,３ｍｉｎ恢复达基础值。由于缺Ｏ２和ＣＯ２潴留对机体各系统均产生不利影响［２］。本研究对４０例心脏直视手术后接受呼吸机辅助呼吸患者,运用呼吸机的“Ｓｉｇｈ”（叹气）作用,在吸痰前后进行过度通气,对吸痰后的动脉血氧分压（ＰａＯ２）和二氧化碳分压（ＰａＣＯ２）情况进行了观察和分析。１　临床资料１．１　对象　本组４０例,按手术的先后随机分为实验组和对照组。实验组２０例…     

两种不同吸痰管对血氧影响的临床观察

充氧－吸痰双腔管对预防吸痰诱发的低氧血症效果明显。３０例经气管导管吸痰的病人，分别在机械辅助呼吸时，（ｎ＝３０）为对照组；常规单腔吸痰管吸痰１５Ｓ，（ｎ＝３０）为实验Ａ组；充氧－吸痰双腔管吸痰１５Ｓ，（ｎ＝３０）为实验Ｂ组。抽血做动脉血气分析。实验结果表明：对照组与实验Ａ组比，ＰＯ２差异非常显著（Ｐ＜０．０１）；而对照组与实验Ｂ组比，ＰＯ２无明显差异（Ｐ＞０．０５）。提示：充氧－吸痰双腔管可预防吸痰诱发的低氧血症，尤其适用危重病人的吸痰操作。     

综合医院患者动脉血氧饱和度的研究

目的：了解临床送检动脉血标本的动脉血氧饱和度（ＳａＯ２）计算值和测定值的误差大小，以及用ＳａＯ２计算值指导临床实践是否可靠。方法：用临床各科送检的３１００份动脉血气标本测定值的有关数据，描绘动脉血氧分压（ＰａＯ２）血氧饱和度（ＳａＯ２）关系图及ＰａＯ２血氧含量（Ｏ２ＣＴ）关系图。结果：ＰａＯ２与ＳａＯ２的关系图不是单一的一条曲线，而是一个“Ｓ”形的区域带。当ＰａＯ２＝８．００ｋＰａ（１ｋＰａ＝７．５ｍｍＨｇ）时，ＳａＯ２变化范围为０．７２～０．９８；而当ＳａＯ２＝０．９０时，ＰａＯ２范围为６．００ｋＰａ～１２．２０ｋＰａ，实际半饱和氧分压（Ｐ５０）范围从２．１９ｋＰａ～１０．８８ｋＰａ，而ＰａＯ２与Ｏ２ＣＴ二者几乎无相关性。当ＰａＯ２＝８．００ｋＰａ时，Ｏ２ＣＴ范围为２．５４ｍｍｏｌ／Ｌ～９．１９ｍｍｏｌ／Ｌ，分布范围很大。结论：由ＰａＯ２和标准血红蛋白氧解离曲线推算ＳａＯ２、Ｏ２ＣＴ是不可靠的，ＳａＯ２必须直接测定     

紫外线照射充氧自血回输治疗重型颅脑损伤合并低氧血症

目的：寻求有效治疗方法，进一步减少颅脑损伤患者致残率及死亡率。方法：将６５例重型颅脑损伤（ＧＣＳ≤８分）合并低氧血症患者分为两组，对照组采用常规治疗，紫外线充氧自血回输治疗（ＵＢＩＯ）组在常规治疗基础上于入院后１，３，５，７天加用ＵＢＩＯ治疗。动态观察患者伤后７天内动脉血氧分压（ＰａＯ２）、血氧孢和度（ＳａＯ２）、肺泡动脉氧压差［Ｐ（Ａ－ａ）Ｏ２］，并于伤后１个月进行疗效评定。结果：伤后１，３，７     

面罩压力支持通气对改善慢性阻塞性肺病患者夜间低氧血症的效果观察

目的：观察面罩压力支持通气对改善慢性阻塞性肺病患者夜间低氧血症的效果。通过双相正压通气（ＢｉＰＡＰ）治疗夜间低氧血症，改善患者心肺功能。方法：对２０例伴夜间呼吸紊乱和低氧血症的慢性阻塞性肺病（ＣＯＰＤ）患者进行未吸氧、鼻导管吸氧、双相正压（ＢｉＰＡＰ）面罩压力支持通气３种状况下的夜间动脉血氧饱和度（ＳａＯ２）、心率、呼吸指标的监测。结果：未吸氧状况下患者夜间低氧血症明显，ＳａＯ２≤０．７２；ＢｉＰＡＰ面罩压力支持通气时ＳａＯ２的升高明显优于鼻导管吸氧，ＳａＯ２＞０．８５（Ｐ＜０．００１）。结论：ＢｉＰＡＰ面罩压力支持通气对改善ＣＯＰＤ患者夜间睡眠和呼吸紊乱，纠正低氧血症有明显作用。     

雾化吸入对慢阻肺伴呼吸衰竭患者血氧饱和度的影响及对策

本文将慢阻肺伴呼衰患者作为实验组，非呼衰患者为对照组，均在血氧饱和度（ＳａＯ２）仪监测下行雾化吸入治疗。动态记录吸入前、吸入后的ＳａＯ２变化。将吸入前与吸入后５分钟、１０－１５分钟的数值取差值ｄ，经ｔ检验，得出实验组在吸入前后的ＳａＯ２的差异有显著性（Ｐ＜０．０５）。而对照组经ｔ检验，Ｐ＞０．０５。得出吸入前后的ＳａＯ２差异无显著性。并提出了有效的吸入方法。     

阻塞性睡眠呼吸暂停综合征夜间低氧血症与室性心律失常的关系

目的：探讨阻塞性睡眠呼吸暂停综合征（ＯＳＡＳ）患者夜间低氧血症与室性心律失常的相互关系。方法：选择拟诊ＯＳＡＳ患者６０例和正常对照组２０名进行多导睡眠图检查。结果：①ＯＳＡＳ组中，睡眠呼吸暂停低通气指数（ＡＨＩ）、动脉血氧饱和度（ＳａＯ２）降低大于０．０４总次数、ＳａＯ２低于０．９０的时间及其降低幅度均明显高于正常对照组（均Ｐ〈０．００１）；睡眠中ＳａＯ２最低值、平均值均低于对照组（均Ｐ〈０．００     

稳定期慢性阻塞性肺疾病患者运动时低氧血症的发生及相关因素

目的：探讨运动时低氧血症与静息时常规肺功能和血气分析指标、运动后呼吸生理改变及最大运动能力的关系。方法：３０ 例稳定期中重度慢性阻塞性肺疾病（ＣＯＰＤ）患者，运动前进行肺功能检查和血气分析。应用自行车功率仪进行递增负荷运动试验，运动过程通过呼吸感应性体表描记仪监测胸腹呼吸运动之和与潮气量之比（ＴＣＤ／ＶＴ） 。结果：３０ 例受试者中１４ 例运动时出现低氧血症，其常规肺功能指标和最大运动能力指标均显著低于其余１６例。极量运动时血氧饱和度（ＳａＯ２ｍｉｎ） 与静息时ＰａＣＯ２ 和ＲＶ／ＴＬＣ 显著负相关，与ＦＥＶ１ ％ ｐｒｅｄ 、ＦＶＣ％ ｐｒｅｄ、ＭＶＶ％ ｐｒｅｄ 和ＰａＯ２ 等均有一定的相关性；极量运动时ＳａＯ２ 下降幅度与静息时ＰａＣＯ２ 、ＰａＯ２ 和ＲＶ 显著相关；ＳａＯ２ｍｉｎ与ＴＣＤ／ＶＴ 的变化负相关；ΔＳａＯ２ 与ＶＥｍａｘ 相关；ＳａＯ２ｍｉｎ 和ΔＳａＯ２ 与最大运动能力指标无明显的相关性。结论：ＣＯＰＤ患者运动时可出现低氧血症，肺充气过度和通气功能损害是引起运动时低氧血症的主要因素，运动时诱发的胸腹矛盾呼吸和运动时通气不足对低氧血症的发生有一定的影响；运动时低氧血症与最大运动能力无明显的相关性。     

吗啡的不同给药方法对急性肺水肿患者的血气影响

采用吗啡不同剂量和给药途径治疗急性肺水肿５０例，临床和血气分析结果显示：静脉用药（吗啡４ｍｇｉｖ）患者缺氧缓解时间快，血氧饱和度（ＳａＯ＿２）和氧分压（ＰａＯ＿２）回升明显，呼吸抑制发生较少，与肌肉和皮下用药比较３组差异显著（Ｐ＜０．０５）。提示吗啡治疗急性肺水肿应早期、静脉和足量的原则，较佳剂量为４～５ｍｇｉｖ，并对吗啡的治疗作用作了初步分析。     

Continuous, in vivo pulmonary venous admixture from fiberoptically measured hemoglobin saturations

In six anesthetized swine, pulmonary venous admixture (Qsp/Qt) was calculated by four methods: a) Qsp/Qt 1, fiberoptically measured arterial and mixed venous Hgb saturation (SaO2 and SvO2), PaO2 and PvO2 derived from saturations; b) Qsp/Qt 2, fiberoptically measured SaO2 and SvO2, PaO2 and PvO2 measured by blood gas analysis; c) Qsp/Qt 3, PaO2 and PvO2 measured by blood gas analysis, SaO2 and SvO2 derived from tensions; d) Qsp/Qt 4, SaO2 and SvO2 measured by bench oximetry, PaO2 and PvO2 derived from saturations. Input from the fiberoptic catheters was fed into a computer programmed to calculate Qsp/Qt 1 every 20 sec. Fifty-eight of these values were compared with simultaneously calculated Qsp/Qt 2, 3, and 4. There was no difference between fiberoptic and derived SaO2 or fiberoptic and cooximetric SvO2. Correlations and slopes for Qsp/Qt 1 with Qsp/Qt 2, 3, and 4 were significant (p less than .05). Comparing mean differences, Qsp/Qt 1 was significantly different only from Qsp/Qt 3 (p less than .01). We conclude that dual oximetry reliably tracks Qsp/Qt.     

Venous oxygen measurements in the inferior vena cava in neonates with respiratory failure

BACKGROUND: The present study was undertaken to examine the feasibility of venous oxygen measurements in the inferior vena cava (IVC) via a catheter through the umbilical vein. This may serve as a proxy for mixed venous oxygenation and the complications of right atrial cannulation can be avoided at the same time. It has the added advantage of not being affected by atrial right-left shunting. RESULTS: The study included 22 neonates requiring mechanical ventilation for respiratory insufficiency. The success rate of catheterization of the IVC via the umbilical vein was 81% and there was no catheter-related complications. Fifty paired blood samples were obtained and analyzed while the patients were hemodynamically stable. Linear regression analysis showed a poor correlation between arterial oxygen tension (PaO2) and the arterial-venous oxygen content difference [C(a-v)O2], r = -0.005, and between PaO2 and the fractional oxygen extraction (FOE), r = -0.114. There was also a poor correlation between arterial oxygen saturation (SaO2) and C(a-v)O2, r = -0.057, and between SaO2 and FOE, r =-0.139. The correlations between venous oxygen tension (PvO2) and C(a-v)O2 and between PvO2 and FOE were r = -0.528 and r = 0.592, respectively. There were good correlations between various oxygen saturation (SvO2) and C(a-v)O2, r = -0.634, and between SvO2 FOE, r = -0.712. CONCLUSION: Venous oxygen measurement in the IVC via an umbilical vein catheter is a simple and safe procedure and provides information about the tissue oxygenation status of critically ill neonates.     

New endotracheal tube adaptor reducing cardiopulmonary effects of suctioning

The continuous recordings of arterial oxygen saturation (SaO2) and beat-to-beat heart rate before, during, and after tracheobronchial suctioning were studied in eight preterm infants with severe RDS receiving mechanical ventilation. Two suctioning procedures were alternatively performed in each infant; In procedure A, disconnection of the ventilator and preoxygenation preceded suctioning; in procedure B, a special suction adaptor was used without ventilatory interruption or preoxygenation; 128 suctionings were performed with each procedure and the changes in heart rate (HR) and SaO2 during suctioning were compared. Although in both procedures, HR and SaO2 decreased during suctioning, the degree of bradycardia and arterial blood oxygen desaturation were significantly smaller in magnitude and shorter in duration during procedure B. These data indicate advantages of the suction adaptor in minimizing bradycardia and hypoxia from airway suction.     

密闭式吸痰对急性呼吸窘迫综合征小猪呼吸及循环系统的影响

[目的]探讨密闭式吸痰对急性呼吸窘迫综合征(ARDS)小猪动脉血气、呼吸力学和心率(HR)、血压的影响。[方法]先制作小猪ARDS模型,模型成功后将其随机分为呼气末正压(PEEP)5cmH2O组和10cmH2O组,予机械通气30min后进行密闭式吸痰。监测吸痰前1min及吸痰后1min、3min、5min、10min动脉血气、呼吸力学及HR、血压的变化。[结果]两组在密闭式吸痰后动脉血氧分压(PaO2)和动脉血氧饱和度(SaO2)均下降,直到吸痰后10min仍低于吸痰前基线水平(P<0.05),而吸痰后舒张压(DBP)与吸痰前比较均无差异(P>0.05);在PEEP5cmH2O组,吸痰后气道峰压(Ppeak)、平台压(Pplat)、平均气道压(Pmean)均升高,持续到吸痰后10min仍显著高于吸痰前基线水平(P<0.05);肺静态顺应性(Cs)、平均动脉压(MAP)、收缩压(SBP)均降低,持续到吸痰后10min仍低于吸痰前基线水平(P<0.05);在PEEP10cmH2O组,吸痰后1min及3minPpeak显著升高(P<0.05),持续到吸痰后10min仍高于吸痰前基线水平但差异无统计学意义(P>0.05);Pplat、Pmean在吸痰后1min显著增高,在吸痰后3min、5min、10min仍高于吸痰前基线水平但无统计学差异(P>0.05),同时在吸痰后1min及3minCs显著下降(P<0.05),持续到吸痰后10min仍低于吸痰前基线水平但差异无统计学意义(P>0.05)。[结论]不论在PEEP5cmH2O还是10cmH2O水平,密闭式吸痰可引起ARDS小猪较严重的低氧血症,使气道压力增高、肺顺应性降低、血压下降。但在PEEP5cmH2O组,吸痰所引起的缺氧、气道高压及低血压持续时间较长。     

Preoxygenation in critically ill patients requiring emergency tracheal intubation

OBJECTIVE: To determine the effectiveness of preoxygenation with 100% oxygen in the critically ill patient in preparation for emergency tracheal intubation. DESIGN: Nonrandomized, controlled trial. SETTING: Large, level 1 trauma center, tertiary care intensive care unit. PATIENTS: Critically ill patients failing noninvasive respiratory support techniques who require tracheal intubation followed by mechanical ventilation. INTERVENTIONS: A baseline arterial blood gas was obtained on noninvasive therapy and 4 mins post-100% oxygen therapy with a bag-mask assembly. Best effort to achieve a tight-fitting mask seal was pursued coupled with other mask ventilation maneuvers to optimize noninvasive oxygenation and ventilation. MEASUREMENTS AND MAIN RESULTS: A total of 42 patients consecutively intubated during the 15-month study period were studied. The baseline Pao2 (mean +/- sd) with concurrent noninvasive support was 67 +/- 19.6 mm Hg (range, 43-88 mm Hg) and increased a mean of 37 mm Hg to 103.8 +/- 63.2 mm Hg after 4 mins of preoxygenation with 100% oxygen. A total of 36% of patients had minimal changes (+/-5%) in their baseline Pao2, and only 19% increased their baseline Pao2 by at least 50 mm Hg after preoxygenation maneuvers. CONCLUSIONS: The critically ill patient has little reserve to tolerate interruption of oxygen delivery and, thus, is at risk for hypoxemia during emergency airway management. Preoxygenation efforts as described in this clinical trial appear to be marginally effective in regard to providing a reasonable safeguard against hypoxemia during laryngoscopy and endotracheal intubation.     

不同吸痰方式对肺不张病人动脉血气的影响

[目的]观察不同吸痰方式对肺不张病人动脉血气的影响。[方法]选择24例肺不张并机械通气的危重病人,随机分为两组,密闭式吸痰(CS)组(n=13)和开放式吸痰(OS)组(n=11)。观察两组吸痰前1min及吸痰后3min、20min动脉血pH值、氧分压(PaO2)、二氧化碳分压(PaCO2)、血氧饱和度(SaO2)的变化。[结果]OS组吸痰后3min、20min与吸痰前1min比较,PaO2、SaO2显著下降,差异有统计学意义(P<0.05);CS组吸痰前后上述参数变化比较无统计学意义(P>0.05);与CS组同时段比较,OS组吸痰后PaO2、SaO2显著下降,差异有统计学意义(P<0.05)。[结论]肺不张病人选择CS方式吸痰能较好地维持机体氧合状态。     

Physiologic rationale of Sv-O2 monitoring

Mixed venous oxygen saturation is a global indicator of the balance between oxygen transport and oxygen demand. In critically ill patients, the delivery of adequate quantities of oxygen to meet the cellular oxygen demands is paramount. While parameters such as SaO2, PaO2, and CO reveal important information about oxygen transport, the SvO2 indicates the adequacy of supply in relation to tissue oxygen demands.     

不同吸痰方式对肺不张病人动脉血气的影响

[目的]观察不同吸痰方式对肺不张病人动脉血气的影响。[方法]选择24例肺不张并机械通气的危重病人，随机分为两组，密闭式吸痰（CS）组（n=13）和开放式吸痰（OS）组（n=11）。观察两组吸痰前1min及吸痰后3min、20min动脉血pH值、氧分压（PaO2）、二氧化碳分压（PaCO2）、血氧饱和度（SaO2）的变化。[结果]OS组吸痰后3min、20min与吸痰前1min比较，PaO2、SaO2显著下降，差异有统计学意义（P〈0．05）；CS组吸痰前后上述参数变化比较无统计学意义（P〉0．05）；与CS组同时段比较，OS组吸痰后PaO2、SaO2显著下降，差异有统计学意义（P〈0．05）。[结论]肺不张病人选择CS方式吸痰能较好地维持机体氧合状态。     

Preoxygenation of patients for coronary artery bypass grafting: vital capacity versus tidal breathing

Arterial oxygenation, as measured by serial arterial blood gases (ABGs) and in vivo polarographic PaO2 during the rapid sequence induction of general endotracheal anesthesia, was evaluated in 20 ASA physical class IV subjects undergoing elective coronary artery bypass grafting (CABG). Subjects received a narcotic premedication 30-60 minutes prior to arrival in the operating room. Subjects in Group I (n = 10) were preoxygenated with 3 minutes of tidal breathing, while Group II (n = 10) subjects took four vital capacity breaths (VCB) within 30 seconds. Manual ventilation was withheld after the period of preoxygenation (the mean duration of apnea was 121.25 seconds). The mean PaO2 rose from 69.40 mmHg to 323.80 mmHg after preoxygenation in Group I and from 73.70 mmHg to 359.10 mmHg in Group II. After tracheal intubation, the mean PaO2 fell to 275.70 mmHg in Group I compared with 277.20 mmHg in Group II. There was no significant difference (p greater than 0.05) between the two methods of preoxygenation in their ability to increase arterial oxygen. In conclusion, vital capacity breathing is as effective as 3 minutes of tidal breathing in elevating the PaO2 in subjects with significant coronary artery disease prior to a rapid sequence induction.