Reversal of intractable septic shock with norepinephrine therapy

Ten patients with severe septic shock were studied. After plasma volume expansion to an optimal pulmonary artery wedge pressure, above which there were no further increases in cardiac index, all patients remained hypotensive and oliguric. The arterial hypotension was unresponsive to increasing doses of dopamine and dobutamine alone and to a fixed combination of both. In all patients studied, infusion of norepinephrine alone reversed the hypotension and increased significantly the mean arterial pressure, systemic vascular resistance and left ventricular stroke work index (p less than .005). There were only minor increases in heart rate. Oxygen transport indices measured in six patients demonstrated variable alterations in oxygen delivery and consumption.     

Shock index: a re-evaluation in acute circulatory failure.

STUDY OBJECTIVE: To evaluate the relationship between the shock index SI (ratio of heart rate to systolic arterial pressure) and cardiac function and oxygen transport in an experimental model of hemorrhage and clinical septic shock. METHODS AND RESULTS: This study was conducted in a hypovolemic circulatory failure model; 40% hemorrhage in the anesthetized pig and normovolemic hyperdynamic septic patients in the intensive care unit (ICU). Hemodynamic and oxygen transport variables were measured and their relationships to SI was examined. SI was inversely related to blood loss, cardiac index (CI), stroke volume (SV), mean arterial pressure (MAP) and left ventricular stroke work (LVSW) (r = -0.73, -0.75, -0.89 and -0.75, respectively P less than 0.01) following hemorrhage in the anesthetized pig. Oxygen transport variables, i.e. oxygen delivery (DO2) and mixed venous oxygen saturation (SvO2P) (r = -0.68 and -0.74, respectively, P less than 0.01) were also inversely related to the SI. Oxygen consumption (VO2) increased initially with increasing SI and fell when SI was greater than 3.0. In clinical septic shock and following blood volume expansion, the SI was not correlated to CI, SVI, MAP or systemic vascular resistance (SVR) (r = -0.01, -0.47, -0.34 and -0.14, respectively, P-value NS) but was inversely related to LVSWI (r = -0.68, P less than 0.01). There were no relationships between the SI and oxygen transport variables (DO2, SvO2) (r = -0.02 and -0.17, P-value NS) in septic shock. CONCLUSION: SI provides a non-invasive means to monitor deterioration or recovery of LVSW during acute hypovolemic and normovolemic circulatory failure and its therapy. SI may be of limited value in the assessment of systemic oxygen transport and response to therapy in clinical shock.     

Donitriptan selectively decreases jugular venous oxygen saturation in the anesthetized pig: further insights into its mechanism of action relevant to headache relief

The effects of donitriptan on systemic arterial-jugular venous oxygen saturation difference were evaluated in pentobarbitone-anesthetized pigs. Oxygen and carbon dioxide partial pressures in systemic arterial and jugular venous blood as well as hemoglobin oxygen saturation were determined by conventional blood gas analysis. Vehicle (40% polyethyleneglycol in saline, n = 9) or donitriptan (0.01, 0.04, 0.16, 0.63, 2.5, 10, and 40 microg/kg, n = 7) were cumulatively infused over 15 min/dose. The involvement of 5-hydroxytryptamine(1B) (5-HT(1B)) receptors was assessed in the presence of the 5-HT(1B/1D) receptor antagonist, GR 127935. Donitriptan decreased markedly and dose dependently jugular venous oxygen saturation [ED(50) 0.5 (0.3-1.1) microg/kg], in parallel with increases in carotid vascular resistance [ED(50) 0.9 (0.7-1.1) microg/kg]. Since arterial oxygen saturation and partial pressure remained unchanged, donitriptan significantly increased arteriovenous oxygen saturation difference from 0.63 microg/kg (maximal variation: 57 +/- 18%, P < 0.05 compared with vehicle). Unexpectedly, donitriptan from 2.5 microg/kg induced marked and significant increases in carbon dioxide partial pressure (pVCO(2)) in venous blood (maximal increase 18.8 +/- 5.7%; P < 0.05 compared with vehicle). Pretreatment with GR 127935 (0.63 mg/kg, n = 5) abolished the fall in venous oxygen saturation and the increase in carotid vascular resistance and reduced the increases in pVCO(2) induced by donitriptan. The results demonstrate that donitriptan, via 5-HT(1B) receptor activation, decreases the oxygen saturation of venous blood draining the head, concomitantly with cranial vasoconstriction. Since donitriptan also increased pVCO(2), an effect upon cerebral oxygen consumption and metabolism is suggested in addition to cranial vasoconstriction, which may be relevant to its headache-relieving effects.     

危重病患者循环内皮细胞数量和氧代谢指标的动态变化

目的探讨危重病患者循环内皮细胞（CEC）数量、氧代谢指标的动态变化。方法35例危重病患者，20例健康体检者作为对照。用等密度梯度离心法分离血CEC，危重病患者右颈内静脉Swan Ganz导管血流动力学监测，于病后3、6、9和12d又各采集静脉血2mL，并记录其氧分压、血氧饱和度（SaO2）、血红蛋白（Hb）、CEC等指标，计算氧供（DO2）、氧耗（VO2）。结果危重病组与正常对照组比较，CEC数量明显增加，差异有显著性（P〈0.05）。危重病组患者3d内VO2随DO2增加的幅度增大，表明DO2和VO2呈病理性依赖关系；但3d后随着DO2增加，VO2的增加速度明显趋于平缓，VO2与DO2之间呈非依赖性关系。结论危重病患者血管内皮细胞功能受损，氧耗增加。     

无痛经食管超声心动图与普通经食管超声心动图应用价值的对比研究

目的与普通TEE进行比较,探讨无痛经食管超声心动图(TEE)在安全性、患者舒适度及诊疗效果方面的临床应用价值。方法连续性收集我院接受普通经食管超声检查的患者116例(普通TEE组)和接受无痛TEE检查的患者80例(无痛TEE组)。监测并评估两组患者生命体征监测,记录并比较TEE检查失败率、一次性插管成功率、检查时间及并发症,评估各超声图像满意度,以及患者舒适度视觉模拟量表(VAS)评分。结果①两组生命体征监测情况比较:普通TEE组检查中,患者心率、收缩压及舒张压均显著高于检查前基础状态(均P<0.05),检查后较检查中减低(P<0.05),仍稍高于检查前基础状态;无痛TEE组检查中,患者心率、收缩压及舒张压均较检查前降低(均P<0.05),检查后升高但与检查前基础状态比较差异无统计学意义;②TEE检查失败率、一次性插管成功率、检查时间及并发症比较:无痛TEE组均成功放置经食管超声探头,普通TEE组6例未能完成常规TEE置管;无痛TEE组一次性插管成功率显著高于普通TEE组(87.5%vs.75.9%),检查时间显著长于普通TEE组[(13.2±4.4)min vs.(5.3±2.0)min],差异均有统计学意义(均P<0.05);无痛TEE组10例(12.5%)检查后出现恶心、呕吐、咽喉疼痛,显著低于普通TEE组[32例(27.6%)],差异有统计学意义(P=0.011);③各组TEE图像获取满意度:无痛TEE组中98.8%的病例图像清晰满意,而普通TEE组中仅65.5%的图像满意,差异有统计学意义(P<0.05);④两组患者舒适度VAS评分比较:无痛TEE组VAS评分显著低于普通TEE组评分[(0.4±0.8)分vs.(3.3±1.7)分],且患者再次行TEE检查的意愿显著高于普通TEE组(92.5%vs.51.7%),差异均有统计学意义(均P<0.01)。结论无痛TEE是一项安全、有效的检查方法,与普通TEE相比,更适用于病情较重的患者,能够为患者提供更为舒适的检查体验,有利于获取全面、优质的图像资料,使其更好地服务于临床诊疗评估。     

The relationship between mixed venous and regional venous oxygen saturation during cardiopulmonary bypass

The relationship between mixed venous and regional venous saturation during cardiopulmonary bypass (CPB), and whether this relationship is influenced by temperature, has been incompletely elucidated. Thirty patients undergoing valve and/or coronary surgery were included in a prospective, controlled and randomized study. The patients were allocated to two groups: a hypothermic group (28 degrees C) and a tepid group (34 degrees C). Blood gases were analysed in blood from the hepatic vein and the jugular vein and from mixed venous blood collected before surgery, during hypothermia, during rewarming, and 30 min after CPB was discontinued. Oxygen saturation in the hepatic vein was lower than in the mixed venous blood at all times of measurement (-24.0 +/- 3.0% during hypothermia, -36.5 +/- 2.9% during rewarming, and -30.5 +/- 3.0% postoperatively, p < 0.001 at all time points). In 23% of the measurements, the hepatic saturation was <25% in spite of normal (>60%) mixed venous saturation. There was a statistical correlation between mixed venous and hepatic vein oxygen saturation (r=0.76, p < 0.0001). Jugular vein oxygen saturation was lower than mixed venous saturation in all three measurements (-21.6 +/- 1.9% during hypothermia, p < 0.001; -16.7 +/- 1.9% during rewarming, p < 0.001; and -5.6 +/- 2.2% postoperatively, p = 0.037). No significant correlation in oxygen saturation could be detected between mixed venous and jugular vein blood (r = 0.06, p = 0.65). Systemic temperature did not influence the differences in oxygen saturation between mixed venous and regional venous blood at any time point. In conclusion, regional deoxygenation occurs during CPB, in spite of normal mixed venous saturation. Mixed venous oxygen saturation correlates with hepatic, but not with jugular, vein saturation. The level of hypothermia does not influence differences in oxygen saturation between mixed venous and regional venous blood.     

The relationship between oxygen delivery and consumption in the conscious rat before and after expansion of body fluid volumes

Oxygen consumption and delivery (defined as the product of cardiac output, haemoglobin concentration and arterial oxygen saturation) and haemodynamic variables were examined in the conscious resting rat throughout the day and after the expansion of body fluid volumes. Cardiac output was measured in arbitrary units by electromagnetic flowmetry and oxygen consumption by respirometry. The variability of blood pressure in the basal state was significantly less than that of cardiac output. Oxygen consumption was significantly correlated with cardiac output and oxygen delivery. In studies undertaken throughout the day, both oxygen consumption and delivery fell in the afternoon and there was evidence that the relationship between these two variables was curvi- rather than recti-linear. During oral sodium chloride administration for 7 days, blood pressure rose and some evidence was found for an alteration in the relationship between oxygen consumption and delivery, with an excess of delivery relative to consumption, particularly on the first day of salt loading. Intravenous injection of sodium chloride solution (0.171 mol/l) did not alter the relationship between oxygen consumption and delivery. Expansion of blood volume, while the packed cell volume was maintained nearly constant, raised oxygen delivery transiently and evidence was obtained that the relationship between oxygen consumption and delivery was altered, with oxygen delivery rising relatively more than oxygen consumption. The findings are discussed in relation to the autoregulatory hypothesis of circulatory control and for the role of autoregulation in hypertensive states. The importance of relating oxygen delivery to metabolic requirements in studies of the role of autoregulation is emphasized.     

不同氧流量影响外科患者氧气雾化吸入效果的研究

目的探讨不同流量的氧气雾化吸入对外科术后患者辅助治疗的效果。方法对90例外科术后行氧驱动雾化吸入的患者进行实验观察,患者随机分为3组,每组30例,3组均行氧气雾化吸入1周,3次/d,15 min/次。各组雾化吸入时氧气驱动的流量分别是≤4 L、6 L、≥8 L,比较3组患者雾化时心率、呼吸、血氧饱和度、主观感觉以及雾化后首次排痰量、肺部痰鸣音消失时间和住院时间。结果 3组间雾化吸入时的心率、呼吸、血氧饱和度、氧流量等4个指标差异无统计学意义,P>0.05。对雾化吸入后的首次排痰量、肺部痰鸣音消失时间、住院时间等3个指标差异有统计学意义,P<0.01或P<0.05。结论氧流量稳定在6 L/min时,雾量适中、吸入合理,患者接受程度高,能达到氧气雾化吸入治疗最佳效果。     

Hemodynamic monitoring in childhood

Hemodynamic monitoring is indicated in children with impending or manifest cardiocirculatory failure. Since cardiocirculatory failure is characterized by an imbalance between oxygen delivery and oxygen demand due to perfusion failure, the parameters monitored should aid in the assessment of these oxygen variables. Oxygen delivery depends on oxygen content and cardiac output. Cardiac output is determined by heart rate and stroke volume; stroke volume by preload, afterload and contractility. Since the direct measurement of oxygen consumption routinely is almost impossible, global oxygen utilization represented by mixed venous oxygen saturation may be used to quantify the relationship between oxygen delivery and oxygen consumption. Justification of invasive hemodynamic monitoring depends among other things on an optimal balance between usefulness of information and complications associated with the techniques used. In future, the development of further noninvasive techniques and the scientific evaluation of recommended monitoring techniques are prospects in cardiovascular monitoring in childhood.     

Hemodynamic monitoring in childhood

Hemodynamic monitoring is indicated in children with impending or manifest cardiocirculatory failure. Since cardiocirculatory failure is characterized by an imbalance between oxygen delivery and oxygen demand due to perfusion failure, the parameters monitored should aid in the assessment of these oxygen variables. Oxygen delivery depends on oxygen content and cardiac output. Cardiac output is determined by heart rate and stroke volume; stroke volume by preload, afterload and contractility. Since the direct measurement of oxygen consumption routinely is almost impossible, global oxygen utilization represented by mixed venous oxygen saturation may be used to quantify the relationship between oxygen delivery and oxygen consumption. Justification of invasive hemodynamic monitoring depends among other things on an optimal balance between usefulness of information and complications associated with the techniques used. In future, the development of further noninvasive techniques and the scientific evaluation of recommended monitoring techniques are prospects in cardiovascular monitoring in childhood.     

Relationship Between Right Atrial and Mixed Venous Oxygen Saturation and Heart Rate During Exercise in Normal Subjects and Patients with Cardiac Disease

FRENCH, W.J., ET AL.: Relationship Between Right Atrial and Mixed Venous Oxygen Saturation and Heart Rate During Exercise in Normal Subjects and Patients with Cardiac Disease. An ideal sensing variable for use in rate responsive pacemakers should measure a physiological parameter that closely correlates with heart rate during various activities in a diverse group of subjects. Nineteen patients, 12 normal and 7 patients with heart disease, were studied to assess the relationship between mixed venous oxygen saturation and heart rate. In patients with heart disease right atrial oxygen saturation and heart rate were also compared. Each subject underwent pulmonary artery catheterization and performed seated cycle ergometer exercise. Gas exchange and heart rate were measured continuously and blood sampled at frequent intervals. Normal patients were studied at rest and during steady-state exercise (mean work rate 149 watts). Patients were studied at rest, steady-state exercise [mean work rate 37 watts), and during incremental exercise (5–10 wattsimin) to tolerance. There were 248 paired right atrial or mixed venous oxygen saturation/heart rate observations obtained. Changes in mixed venous oxygen saturation and heart rate were not substantially altered by fitness or cardiac disease. Rate responsive pacemakers sensing changes in oxygen saturation may be a superior sensing variable for both normal and patients with heart disease.     

Ventilatory effects of neurophysiological facilitation and passive movement in patients with neurological injury

Thirteen intubated, high dependency patients with neurological injuries were studied in order to investigate the short term respiratory effects of neurophysiological facilitation and passive movement on tidal volume (VT), minute ventilation (VE), respiratory rate (VR) and oxygen saturation (SpO2). The subjects were studied under four conditions: no intervention (control) and during periods of neurophysiological facilitation, passive movement and sensory stimulation. All periods were standardised to three minutes duration and all parameters were recorded before and after each intervention. Neurophysiological facilitation produced significant increases (p < 0.01) in VE and SpO2 (p < 0.05) when compared with control values, with an overall mean increase in VE of 14.6%. Similarly, passive movement increased VE (p < 0.01) by an average of 9.8% and also increased SpO2 (p < 0.01). In contrast, sensory stimulation produced significant increases (p < 0.01) in SpO2 with control levels, with no significant change in VT or VE. There was no significant difference in VR with all treatments. This study provides preliminary evidence of improved short term ventilatory function following neurophysiological facilitation, independent of generalised sensory stimulation, which has not been previously examined in the literature, supporting its use in the management of high dependency neurological patients.     

Effects of ubidecarenone in an exercise training program for patients with chronic obstructive pulmonary diseases.

A study was undertaken to determine the usefulness of ubidecarenone in pulmonary rehabilitation in exercise training programs in the management of chronic obstructive pulmonary disease (COPD). The subjects were 20 patients with COPD who had been participating in an exercise training program for at least four weeks. The patients were randomly assigned either to receive 50 mg of oral ubidecarenone daily or to enter a control group during the program. Oxygen consumption, expired volume, and heart rate were measured during exercise tests before and after training. Maximum oxygen consumption increased 13% in the ubidecarenone-treated patients and 7% in the controls, and maximum expired volume increased 10% in each group. The increases were significant in the ubidecarenone group but not in the controls. Heart rate increased 2% in both groups. It is concluded that ubidecarenone deserves further evaluation in exercise training programs for patients with COPD.     

老年心血管患者拔牙中血压、心率及血氧饱和度监测的意义

目的：评价老年心血管病患者在拔牙中监测血压、心率、血氧饱和度临床意义。方法：对205例老年拨牙患者分成心血管病组和非心血管病组，拨牙中分别进行心电监护，观测术前、术中及术后心率、血压、血氧饱和度的变化，并比较两组的差别。结果：所有患者的血压、心率、血氧饱和度3项指标在围拔牙期均发生变化，拔牙术中血压升高，心率加快，血氧饱和度下降；心血管病组患者的变化更明显，与非心血管组患者相比较，有显著差别（P＜0．05）。结论：老年心血管病患者在拔牙过程中监测血压、心率、血氧饱和度的变化有利于提高拔牙手术的安全性。     

急救车转运途中不同体位循环呼吸功能变化的研究

目的观察不同转运体位下健康人急救车转运途中循环呼吸功能的变化情况。方法将青年志愿者20名纳入实验,采用自身对照,分别设计顺车体头朝前平卧、顺车体头朝后平卧及垂直车体平卧三种体位,分析不同体位急救车转运途中心率、收缩压、呼吸及血氧饱和度的变化情况。结果三种体位收缩压均出现较基础值先下降后回复的轻微改变（P〈0．01）,变化幅度从大到小的排序依次为顺车体头朝前平卧、顺车体头朝后平卧和垂直车体平卧,其余指标心率、呼吸及血氧饱和度值均未发生改变（P〈0．05）。顺车体头朝前平卧组中男性受试者收缩压出现先下降后升高的变化（P〈0．05）,变化幅度较女性受试者大。结论急救车转运途中收缩压的改变可能与转运导致的人体血流重新分布有关。在转运患者途中应加强患者生命体征的监测。     

Oxygen consumption, assessed with the oxygen absorption spectrophotometer, decreases independently of venoconstriction during hepatic anaphylaxis in perfused rat liver

Anaphylactic shock is accompanied by a decrease in oxygen consumption. However, it is not well known whether oxygen consumption decreases during local anaphylactic reaction in liver. We determined the effects of anaphylaxis and norepinephrine on oxygen consumption in isolated rat livers perfused portally and recirculatingly at constant flow with blood (hematocrit, 12%). Oxygen consumption was continuously measured by monitoring the portal-hepatic venous oxygen saturation differences using the absorption spectrophotometer, the probes of which were built in perfusion lines. Hepatic anaphylaxis was induced by an injection of ovalbumin (0.01 or 0.1 mg) into the perfusate of the isolated liver of the rat sensitized with subcutaneous ovalbumin (1 mg). Hepatic venoconstriction and liver weight loss were similarly observed in response to norepinephrine (0.01-10 micromol L(-1)) and anaphylaxis. However, hepatic anaphylaxis reduced oxygen consumption, whereas norepinephrine increased it. There was a possibility that anaphylactic venoconstriction could reduce the perfused surface area, resulting in decreased oxygen consumption. However, pretreatment with a vasodilator of sodium nitroprusside substantially attenuated venoconstriction but not the decrease in oxygen consumption during anaphylaxis. Thus, we conclude that local hepatic anaphylaxis decreases oxygen consumption independently of venoconstriction in isolated blood-perfused rat livers.     

Validation of the Nonin 8600V Pulse Oximeter for heart rate and oxygen saturation measurements in rats.

This report validates the use and limitations of the Nonin Pulse Oximeter for measuring heart rate and oxygen saturation in rats. Eight anesthetized Sprague-Dawley rats were intubated and catheterized. Oxygen saturation was directly measured from arterial blood by using a Radiometer OSM3 Hemoximeter adjusted for rat blood as well as indirectly by using the Nonin Pulse Oximeter. Oxygen saturation was changed by varying the level of inhaled oxygen. Heart rate was measured in two ways: 1) by using the signal from the Nonin Pulse Oximeter and 2) by counting the pressure pulses from the transduced blood pressure. There was excellent agreement between heart rate values measured by the Nonin Pulse Oximeter and that measured by counting the pulses from the arterial blood pressure recording. The Nonin Pulse Oximeter underestimated oxygen saturations by about 3% to 5% compared to the Hemoximeter. Overall, the pulse oximeter reflected important trends in oxygen saturations, making it a useful tool for laboratory animal medicine.     

Ventilatory and cardiovascular responses to unsupported low-intensity upper limb exercise in normal subjects

The ventilatory and cardiovascular responses, and the rating of perceived exertion (RPE) to three types of unsupported low-intensity upper limb exercise (static, dynamic - unilateral and bilateral) were investigated in 22 normal subjects. A significant increase in tidal volume, respiratory rate, minute ventilation, oxygen consumption, carbon dioxide production and pulse rate occurred during all three exercises (p < 0.05). With the exception of tidal volume, these increases were significantly greater with dynamic exercise (p < 0.05). Local RPE was significantly higher than general RPE following both static and dynamic exercise (p < 0.05) with no significant differences between the three exercises. These findings provide some basis for the development of exercise protocols for testing in post-operative patients.     

纤维支气管镜检患者不同时间血压心率血氧饱和度的观察及护理

目的探讨纤维支气管镜检查对患者血压、心率、血氧饱和度的影响,提出护理对策。方法选择40例具有检查适应证的患者,分别于检查前30 min、检查前即刻、过声门、检查后即刻、检查后30 min监测记录血压、心率、血氧饱和度。结果过声门与其他4个时段的血压、心率、血氧饱和度分别比较发现,过声门时血压、心率最高,血氧饱和度最低,除外检查前30 min的收缩压和血氧饱和度,检查后30 min的血氧饱和度,其他指标与过声门时差异均有统计学意义,P<0.05;检查后即刻的舒张压、心率与检查前30 min相比仍较高,P<0.05;检查后即刻的心率、血压与检查后30 min相比较高,其中心率的差异显著,P<0.05。结论纤维支气管镜检查对血压、心率、血氧饱和度有较大的影响。检查过程中应加强对血压、心率、血氧饱和度的监测,尤其重视过声门的监护,强调待30 min后患者血压、心率、血氧饱和度正常后,患者才能离开检查室。     

新式叩击手法促进COPD合并感染患者排痰的效果

目的探讨新式胸部叩击手法促进慢性阻塞性肺疾病（chronic obstructive pulmonary disease,COPD）合并感染患者排痰的效果。方法选择我院呼吸科收治的符合COPD合并肺部感染患者94例,随机分为两组,各47例,一组采用新式胸部叩击手法排痰（观察组）,另一组采用传统的背部叩击手法排痰（对照组）。观察两组患者呼吸、血氧饱和度、血气分析、排痰量及住院时间等指标的差异。结果新式胸部叩击手法与传统背部扣击方法相比,在呼吸频率、血氧饱和度、血气分析、排痰量及住院时间等方面差异均有统计学意义（P〈0.01）。结论新式胸部叩击手法提高了胸部物理治疗的临床效果,使痰液能及时有效排出,改善通气氧合功能,缓解憋喘症状,减少并发症,缩短了住院时间,节省了治疗费用,同时提高了护士观察病情的主动性和专业水平,收到了明显的社会和经济效益,具有推广意义。