Agreement of an Inert Gas Rebreathing Device with Thermodilution and the Direct Oxygen Fick Method in Measurement of Pulmonary Blood Flow

Objective. Inert gas rebreathing is a well established method for the non-invasive measurement of pulmonary blood flow. We tested the agreement in measurement of pulmonary blood flow (Qt rb) by a new inert soluble gas rebreathing device, the Innocor (Innovision, Copenhagen), with bolus thermodilution (Qt td) and the direct oxygen Fick (Qt Fick) method. Methods. 9 patients pre- and post-cardiac surgery were recruited resulting in 20 sets of measurements overall. Arterial and mixed venous blood samples were collected simultaneously with a thermodilution measurement and rebreathing manoeuvre to measure both V _O2 and effective pulmonary capillary blood flow. Results. Mean bias (95% confidence limits) was: Qt rb − Qt td 0.01 (± 0.42) L/min; Qt rb − Qt Fick + 0.34 (± 0.59) L/min. The standard deviation of the difference between paired measurements was: Qt td − Qt rb ± 0.89 L/min; Qt Fick − Qt rb ± 1.26 L/min. Conclusions. Acceptable overall agreement between the Innocor and these reference standards was demonstrated.     

Determination of Oxygen,Carbon Dioxide,and Nitrous Oxide in Blood by Gas Chromatography

Abstract

A gas chromatograph (Beckman) was modified for determination of blood O₂, CO₂ and N₂O content with i. a. a new extraction tube. Different characteristics in volume of extraction tube, carrier gas (Helium) flow, volumes of reagents and times for reaction between reagents and blood were investigated. The method was standardized for a blood sample volume of 0.5 ml for O₂ and CO₂ analysis and 1.0 ml for N₂O. The time for a complete analysis of O₂ and CO₂ was 12 min and for N₂O 7 min. Double determinations with the Van Slyke and Neill method and gas chromatography did not differ significantly for either O₂ or CO₂ within the physioldfeical range. N₂O analyses were also consistent with both methods for contents occurring during, e. g., measurement of cerebral blood flow (up to 6 ml/100 ml). The reproducibility determined from duplicate analyses was similar with both methods, with the exception of the N₂O analyses, where the gas chromatograph (M=3.22 ml/100 ml, SD of the mean = 0.009) appeared to yield more consistent values than the Van Slyke and Neill method (M=3.29 ml/100 ml, SD of the mean = 0.020).     

离体皮肤氧耗量测定与微机数据分析系统

目的比较长短氧传感器常规手工计算法和微机数据分析法测定皮片氧耗活力的效果。方法将Wistar鼠薄皮片分别切成直径为15mm和6mm的小皮片,一部分皮片立即测定氧耗量和另一部分皮片液氮冻存。两种氧传感器对每块皮片各测定两次,然后按常规法和微机法计算测定皮片1min的氧耗量。结果两种氧传感器常规法和微机法测定新鲜皮片的氧耗量各组内均无显著性差异(P>0.05);但长氧传感器测定的氧耗量比短氧传感器测得的氧耗量显著高(P<0.05)。两种氧传感器微机法测定皮片的氧耗量比常规法测定皮片的氧耗量显著高(P<0.05)。长氧传感器和微机法测定冻存皮片的氧耗量比新鲜皮片氧耗量显著低(P<0.01)。结论结果提示长氧传感器比短氧传感器测定皮片氧耗量更高、用皮量更少,而微机法比常规法更加简便可靠。     

Induction of anaesthesia by propofol and hepatic blood flow in the rabbit

Summary. Effects of propofol (12.5 mg kg^-1, i.v. bolus injection) or 0.9% sodium chloride on arterial blood pressure, arterial blood gases and hepatic circulation (radio-labelled microsphere technique) were studied in 15 conscious and unpremedicated rabbits. No significant changes were observed after sodium chloride. Propofol resulted in anaesthesia, respiratory depression (-49±14% decrease in PaO₂; mean±SD) and hypotension (-49±13% decrease in mean arterial pressure; mean±SD), but no changes in hepatic arterial and portal venous blood flows. We conclude that propofol does not affect the liver circulation despite marked depression of mean arterial pressure and respiration.     

呼吸内科病区绩效分配考核体系的建立与效果评价

目的:探讨"优质护理服务示范工程"活动试点病房呼吸内科绩效分配考核体系的建立与实施效果。方法:依据护理人员职称系数、岗位系数、工作质量系数来建立考核框架,制定绩效工资考核细则,建立绩效考核手册,作为绩效发放依据。结果:绩效分配考核机制的建立,提高了护理质量及病人满意度。结论:有效的激励机制充分激发了护士工作热情,从而提高了护理质量及病人满意度。     

Measurement of brain natriuretic peptide in plasma samples and cardiac tissue extracts by means of an immunoradiometric assay method

Background: The mechanisms of oxygen‐induced effects on blood vessels (vasoconstriction in hyperoxaemia and vasodilatation during hypoxaemia) are uncertain. Many investigators have suggested that the vasoconstriction seen during hyperoxia/hyperoxaemia is mediated through the endothelium as a result of either increased release or activity of vasoconstrictors (oxygen radicals, endothelin, norepinephrine, angiotensin II, or serotonin (5‐HT)), or reduced activity of vasodilators (prostaglandin E₂ and nitric oxide). Serotonin has been assumed to have a central role. Methods: Eight healthy volunteers were exposed to F_iO₂ of 1.0 for 20?min and serum concentrations of serotonin and activated platelets were measured (indicated by concentrations of β‐thromboglobulin (β‐TG)). Results. During hyperoxaemia in humans, serum concentrations of serotonin and β‐TG remained unchanged. Conclusion: If serotonin is involved in oxygen‐induced vasoconstriction, the mechanism is more likely to be either a potentiating effect of serotonin on other vasoconstrictors or increased activity of serotonin on its receptor.     

氢清除法测定局部血流量的微机数据采集与处理

用ＡＰＰＬＥ－Ⅱ微机对氢清除曲线进行实时采集，按最小二乘法作曲线拟合．自动计算出氢清除曲线的半衰期，从而得出局部血流量的值．拟合前后曲线显示于监示器，并自动由打印机打印出图形及结果．     

不同剂量的佳苏仑用于静吸复合全麻后催醒的临床研究

目的:探讨合适剂量的佳苏仑用于静吸复合全麻后既有较好催醒效果,又能保持生命体征平稳及减少不良反应。方法:60例静吸复合全麻病人随机分A 、B 、C三组,全麻后催醒首剂佳苏仑分别为0.5 mg/kg、1.0 mg/kg和1.5 mg/kg。记录用药前,用药后2 min、5 min、10 min、15 min血压、心率、呼吸次数、潮气量等生命体征数据;观察神志恢复情况及不良反应。结果:患者血压、心率用药后较用药前有不同程度上升,但无显著性差异(P>0.05),B组C组各有2例、5例患者血压、心率上升超过用药前20%以上,未给特殊处理20 min后自行恢复正常;所有病例呼吸次数、潮气量用药后较用药前明显增加(P<0.05),B、C组在5 min、10 min、15min增加明显高于A组(P<0.05);B、C组各有1例和3例出现恶心、出汗、肌肉抽搐,C组1例病人出现惊厥。各组在用药后10 min、15 min共有42例(70%)和47例(78.3%)患者清醒,B、C组5min、10min、15min清醒率明显高于A组(P<0.05)。结论:静吸复合全麻后静注佳苏仑1 mg/kg有较好的催醒和呼吸抑制逆转作用,副作用的发生也较少,是较理想的催醒药物剂量。     

吸氧对纤维支气管镜检查患者相关血气指标的干预和影响

目的:了解中等浓度吸氧在纤维支气管镜(FB)检查中的安全性和价值。方法:在行FB检查人群中随机选择25例，分别观察FB置人气道(置镜)前后及中等浓度吸氧前后患动脉血氧分压(PaO2)、动脉血二氧化碳分压(PaCO2)和血氧饱和度(SpO2)的变化。结果:置镜使患SpO2和Pa02有显下降(P＜0．001)，而PaCO2差异无显性(P＞0．05)。接着吸氧5L／min后，Sp02和PaO2与置镜后比较，有明显提高(P＜0．001)，而PaCO2变化无统计学意义(P＞0．05)。l3例患置镜前和吸氧后PaO2及SpO2比较，差异均具明显显性(P＜0．01)，而PaCO2无明显变化(P＞0.05)。结论:吸中等浓度氧对普通行FB检查的患是安全的，可完全补偿因FB置入所引起的PaO2下降，而对PaCO2影响很小，对于有原发PaCO2升高的患，安全性尚有待进一步研究。     

Measurement of oxygen and carbon dioxide partial pressures in synovial fluid after tonometry

Summary. A commercially available gas analyser was used to measure tension of oxygen (Po₂) and carbon dioxide (Pco₂) in synovial fluid samples after tonometry. Measured values of Pco₂ were close to the expected (median difference 0·2 kPa, range -0·4 to 0·4) within the analysed concentration range of 4·10 kPa. No consistent difference between measured and expected values of Po₂ were found for oxygen in the range 3·11 kPa (median difference 0·1 kPa, range -0·3 to 1·2). For oxygen tensions below 3 kPa, however, the measured values invariably overestimated the actual Po₂, the errors ranging from 0·3 to 1·9 kPa, median 1·1. The importance of proper handling of samples was investigated and storage for 1 h at 0°C in plastic syringes resulted in elevation of the Po₂ levels measured (range of elevation 0·2 to 3·6 kPa, median 1·15), whilst no significant differences were found when stored in glass syringes. Within the limits stated, commercially available gas analysers may thus be used to investigate these parameters related to local tissue metabolism in effusive joint conditions.     

The effects of low-dose dopamine on splanchnic blood flow and oxygen uptake in patients with septic shock

Objective: To assess the effects of low-dose dopamine on splanchnic blood flow and splanchnic oxygen uptake in patients with septic shock. Design: Prospective, controlled trial. Setting: University hospital intensive care unit Patients: 11 patients with septic shock, diagnosed according the criteria of the 1992 American College of Chest Physicians/Society of Critical Care Medicine consensus conference, who required treatment with norepinephrine. Measurements and main results: Systemic and splanchnic hemodynamics and oxygen transport were measured before and during addition of low-dose dopamine (3 μg/kg per min). Low-dose dopamine had a marked effect on total body hemodynamics and oxygen transport. The fractional splanchnic flow at baseline ranged from 0.15 to 0.57. In 7 patients with a fractional splanchnic flow less than 0.30, low-dose dopamine increased splanchnic flow and splanchnic oxygen delivery and oxygen consumption. In 4 patients with a fractional splanchnic flow above 0.30, low-dose dopamine did not appear to change splanchnic blood flow. Conclusion: Low-dose dopamine has a potential beneficial effect on splanchnic blood flow and oxygen consumption in patients with septic shock, provided the fractional splanchnic flow is not already high before treatment. Received: 19 September 1995 Accepted: 21 September 1996     

Measurement of tissue perfusion by oxygen transport patterns in experimental shock and in high-risk surgical patients

Survivors of high-risk general (noncardiac) surgery were observed to have cardiac index (CI) values averaging 4.5 l/min·m², oxygen delivery ( O₂) of >600 ml/min·m², and oxygen consumption ( O₂) of 170 ml/min·m². In contrast, these values were relatively normal in patients who subsequently died. A very early predictive index based on these observations was found to predict outcome in 94% of high-risk patients. The hypotheses that increased- O₂ and O₂ in the survivors represent compensatory physiologic responses and that these values were appropriate therapeutic goals were tested in prospective randomized clinical trials and found to reduce mortality and morbidity significantly. The optimal goals were more easily attained with colloids, red cells, dobutamine, and vasodilators, according to their capacity to improve tissue perfusion, as reflected by increased flow and oxygen transport. The extremely complex interactions between- O₂ and O₂ are reviewed.     

Energetic Cost of Walking and Its Physiological Correlates in Persons With Multiple Sclerosis Who Have Moderate Mobility Disability

Objective

This study examined aerobic capacity, upper leg muscular strength, and static postural control as correlates of the energetic cost of walking (C_w) in moderate multiple sclerosis (MS) mobility disability.

双工超声显像测定室间隔缺损体,肺循环血流量

采用双工超声显像技术测定了２５例先天性室间隔缺损（ＶＳＤ）患者与１２例正常人的右室每搏量（ＲＶＳＶ）与左室每搏量（ＬＶＳＶ），并将手术直视下测得的ＶＳＤ大小与ＲＶＳＶ／ＬＶＳＶ进行了相关性分析．结果表明，正常人ＬＶＳＶ与ＲＶＳＶ几乎相等（Ｐ＞０．０５）。ＶＳＤ患者ＲＶＳＶ明显高于ＬＶＳＶ（Ｐ＜０．００１）；ＶＳＤ患者与正常人相比，ＬＶＳＶ无显著性差异（Ｐ＞０．０５），ＲＶＳＶ明显增加（Ｐ＜０．００１）；ＲＶＳＶ／ＬＶＳＶ亦明显增加（Ｐ＜０．００１）．手术测得的ＶＳＤ大小与ＲＶＳＶ／ＬＶＳＶ显著正相关（ｒ＝０．９１）。因此，双工超声显像能准确测定正常人与ＶＳＤ患者的ＲＶＳＶ与ＬＶＳＶ．ＶＳＤ大小对ＲＶＳＶ／ＬＶＳＶ有明显影响。反之ＲＶＳＶ／ＬＶＳＶ对判断ＶＳＤ大小亦有一定帮助．     

Assessment of the Addition of Prehospital Continuous Positive Airway Pressure (CPAP) to an Urban Emergency Medical Services (EMS) System in Persons with Severe Respiratory Distress

Background

The use of continuous positive airway pressure (CPAP)-assisted ventilation in the prehospital setting has not been well studied.

Objectives

The purpose of this study was to measure the efficacy of adding prehospital CPAP to an urban emergency medical services (EMS) respiratory distress protocol for persons with respiratory distress.

Methods

An historical cohort analysis of consecutive EMS patients presenting during the years 2005–2010. Groups were matched for severity of respiratory distress. Physiologic variables were the primary outcomes obtained from first responders and upon triage in the Emergency Department. Additional outcomes included endotracheal intubation rate, hospital mortality, overall hospital length of stay (LOS), intensive care unit (ICU) admission, and ICU LOS.

Results

There were a total of 410 consecutive patients with predetermined criteria for severe respiratory distress, 235 historical controls matched with 175 post-implementation patients, entered in the study. The average age was 67 years; 54% were men. There were significant median differences in heart and respiratory rates favoring the historical cohort (all p < 0.05). There were no significant differences in intubation rate, overall hospital LOS, ICU admission rate, ICU LOS, or hospital mortality (all p > 0.05). Patients who were continued on non-invasive ventilatory assistance had a significantly improved rate of intubation and ICU LOS (all p < 0.05).

Conclusion

The addition of CPAP to an EMS prehospital respiratory distress protocol resulted in improved heart and respiratory rates. Though not statistically significant, decrease in overall and ICU LOS were observed. Patients with continued ventilatory assistance seemed to have improved rates of intubation and ICU LOS.     

Cardiovascular and adrenergic effects of cigarette smoking during immediate non-selective and selective beta adrenoceptor blockade in humans

The cardiovascular and adrenergic responses to cigarette smoking during acute selective and non-selective beta adrenoceptor blockade were studied in seven young healthy volunteers in a double blind cross-over fashion. Heart rate, arterial blood pressure, forearm blood flow and plasma levels of adrenaline and noradrenaline were determined before and during the terminal 5 min period of 15 min smoking test. During smoking, plasma concentrations of adrenaline increased markedly and evenly by approximately 0.3 ng/ml in all three experimental sessions. Plasma concentrations of noradrenaline remained unchanged. Propranolol, a non-selective beta blocker, caused a marked rise in diastolic and mean blood pressure and forearm vascular resistance during smoking. This response was not seen in the control series or after selective beta-1 blockage with atenolol. This difference is attributable to propranolol's blockade of adrenaline's vasodilating effect mediated by beta-2 receptors in the resistance vessels. Furthermore, atenolol attenuated the systolic blood pressure and tachycardiac responses induced by cigarette smoking by comparison with placebo. This study suggests that selective beta-1 blockers are preferable in the management of patients who are habitual smokers.     

Interaction between leukotriene D4 and adenosine or iloprost in the isolated working guinea-pig heart: prevention of the leukotriene D4 effect

The interaction between leukotriene D4 and adenosine or the prostacyclin analogue iloprost was studied in isolated guinea-pig hearts. Adenosine (1 X 10(-6) M) or iloprost (5 X 10(-8) M) abolished or greatly attenuated the vasoconstrictive effect of leukotriene D4 over a wide dose range of leukotriene D4 (0.01-1000 ng), and myocardial ischemia as a consequence of coronary insufficiency completely disappeared. Comparison of myocardial levels of reduced pyridine nucleotide fluorescence in hearts treated with leukotriene D4 and in hearts subjected to varying degrees of high-flow hypoxia, or the calcium agonist BAY-K 8644, revealed low levels of reduced pyridine nucleotides in the leukotriene D4-treated hearts, suggesting that leukotriene D4 directly suppressed myocardial contractility. These findings were supported by full restoration of cardiac work by the receptor antagonist FPL 55712 following leukotriene D4 treatment. It is concluded that adenosine and iloprost are potent inhibitors of leukotriene D4-induced reduction in coronary flow in guinea-pig hearts, and that myocardial ischaemia and suppressed cardiac work are prevented during leukotriene D4 study in adenosine or iloprost perfused hearts. Low levels of myocardial-reduced pyridine nucleotides during leukotriene D4 treatment and restoration of cardiac work by FPL 55712 indicate that leukotriene D4 may also have a direct suppressive effect on myocardial contractility.     

脉冲多普勒对原发性肝癌肝动脉及门脉静血流的定量测定

本文应用脉冲多普勒对36例原发性肝癌、16例肝内良性占位性病变及13例晚期肝硬化的肝总动脉(CHA)、肝固有动脉(PHA)、及门静脉的血流做定量测定,并用34例正常人做对照。正常人CHA血流量为277±148ml/min,PHA血流量为182±101ml/min。原发性肝癌CHA血流量为1114±480ml/min,PHA血流量为850±504ml/min,明显高于正常人组(P<0.0001),亦明显高于各组(P<0.0001),而门静脉血流量仅稍高于正常人组,和肝硬化组无明显差别。故肝动脉血流的测定对肝内占位性病变良恶性的鉴别有重要意义,其灵敏度为71.4％(CHA血流量指标)及64.2％(PHA血流量为指标),特异度为100％,准确度为79.5％及74.3％。