Non-invasive and quantitative near-infrared haemoglobin spectrometry in the piglet brain during hypoxic stress, using a frequency-domain multidistance instrument

The frequency-domain multiple-distance (FDMD) method is capable of measuring the absolute absorption and reduced scattering coefficients of optically turbid media. Absolute measurement of absorption at two near-infrared (NIR) wavelengths makes possible the quantitation of tissue haemoglobin concentration and tissue haemoglobin oxygen-saturation (StO2). However, errors are introduced by the uncertainties of background absorption and the dissimilarities between real tissues and the simplified mathematical model on which these measurements are based. An FDMD-based tissue instrument has been used for the monitoring of tissue haemoglobin concentration and oxygenation in the brain of newborn piglets during periods of hypoxia and hyperoxia. These tissue haemoglobin saturation values were compared with arterial saturation (SaO2) and venous saturation (SvO2) measured by blood gas analyses. A linear correlation was observed between StO2 and the average of SaO2 and SvO2. However, StO2 is not equal to any fixed weighted average of SaO2 and SvO2 unless we introduce an effective background tissue absorption. The magnitude of the background absorption was about 0.08 cm(-1) at 758 nm and 0.06 cm(-1) at 830 nm, and it was nearly consistent between piglets. The origin of this 'effective' background absorption may be real, an artefact caused by the application of a simplified model to a complex sample, or a combination of factors.     

Quantification of cerebral hemoglobin as a function of oxygenation using near-infrared time-resolved spectroscopy in a piglet model of hypoxia

Near-infrared spectroscopy (NIRS) has been used for measurement of cerebral hemoglobin (Hb) concentrations in neonates to study cerebral oxygenation and hemodynamics. We perform measurements by portable three-wavelength NIR time-resolved spectroscopy (TRS) in a piglet hypoxia model with various degrees of oxygenation to estimate the absorption coefficient (mu(a)) and reduced scattering coefficient (mu(s)') of the head. Measurements of absolute values of mu(a) at three wavelengths enable estimation of Hb concentration and Hb oxygen saturation in the head (SO2). However, there is a problem concerning which background absorption should be used to estimate Hb concentration in the head derived from mu(a) at three wavelengths because it is different from a simple in vitro model. Therefore, we use two different background absorption values with the assumption that background absorption is due only to 85% (by volume) water or that background absorption is equal to absorption of the piglet head with blood exchange transfusion by fluorocarbon (FC), and we compared SO2 measured by TRS with arterial Hb oxygen saturation (SaO2) and sagittal sinus venous Hb oxygen saturation (SvO2) measured by a co-oximeter at several inspired fractional O2(FI(O2)) concentrations. We find that SO2 values using the absorption (abs) of the piglet head with blood exchange transfusion (BET) by FC are not significantly different from SO2 values using the water-only background at FI(O2) in the range of 15 to 100%, but that the values using abs of the head with BET by FC are lower than the values using the water-only background at FI(O2) in the range of 12 to 4%. The SO2 values calculated from the water-only background are higher than those of SaO2 at FI(O2) in the range of 10 to 4%. However, SO2 values using the abs of the head with BET by FC are between those of SaO2 and SvO2 over the whole range of FI(O2). Therefore, abs of the head with BET by FC is more useful for estimation of the absolute values of oxyHb and deoxyHb of the piglet head.     

Pulse oximetry in the pulmonary tissue for the non-invasive measurement of mixed venous oxygen saturation

The oxygen saturation of the systemic arterial blood is associated with the adequacy of respiration, and can be measured non-invasively by pulse oximetry in the systemic tissue. The oxygen saturation of the blood in the pulmonary artery, the mixed venous blood, reflects the balance between oxygen supply to the systemic tissues and their oxygen demand. The mixed venous oxygen saturation has also clinical significance because it is used in Fick equation for the quantitative measurement of cardiac output. At present the measurement of the mixed venous oxygen saturation is invasive and requires insertion of a Swan-Ganz catheter into the pulmonary artery. We suggest a noninvasive method for the measurement of the mixed venous oxygen saturation in infants, pulmonary pulse oximetry. The method is similar to the systemic pulse oximetry, which is based on the different light absorption curves of oxygenated and deoxygenated hemoglobin and on the analysis of photoplethysmographic curves in two wavelengths.     

Recirculation in double lumen catheter veno-venous extracorporeal membrane oxygenation measured by an ultrasound dilution technique

Recirculation is a limiting factor for oxygen delivery in double lumen catheter veno-venous extracorporeal membrane oxygenation (DLVV-ECMO). This study compares three different methods for the determination of the recirculation fraction during double lumen catheter veno-venous ECMO at ECMO flow rates of 150, 125, 100, 75, and 50 ml/kg.min in nine lambs: (1) an ultrasound dilution method, in which the change in ultrasound velocity in blood after injection of a saline bolus as a marker is used for determination of recirculation; (2) an SvO2 method using real mixed venous blood oxygen saturation, the gold standard, for determination of recirculation fraction; and (3) the CVL method, in which oxygen saturation of a blood sample of the inferior vena cava is considered to represent mixed venous oxygen saturation. In all methods, the recirculation fraction increased with increasing ECMO flow rate. The correlation coefficient between the ultrasound dilution method and the SvO2 method was 0.68 (p < 0.01); mean difference was -2.4% (p = 0.6). Correlation coefficient between the ultrasound dilution method and the CVL method was 0.48 (p < 0.01); mean difference was -18.1% (p < 0.01). The correlation coefficient between the SvO2 method and the CVL method was 0.51 (p < 0.01); mean difference was -15.7% (p < 0.01). The ultrasound dilution method is a useful method for measurement of the recirculation fraction in DLVV-ECMO and is easier to use than the other methods.     

Noninvasive measurement of cerebral hemoglobin oxygen saturation using two near infrared spectroscopy approaches

Spatially resolved spectroscopy (SRS) is a new near infrared spectroscopy (NIRS) method that, using the multi-distance approach, measures local cerebral cortex hemoglobin oxygen saturation [J. Matcher, P. Kirkpatrick, K. Nahid, M. Cope, and D. T. Delpy, Proc. SPIE 2389, 486-495 (1995)]. Using a conventional continuous wave NIRS photometer, cerebral venous oxygen saturation (SvO2) can be calculated from oxyhemoglobin and total hemoglobin rise induced by partial occlusion of jugular vein [C. E. Elwell, S. J. Matcher, L. Tyszczuk, J. H. Meek, and D. T. Delpy, Adv. Exp. Med. Biol. 411, 453-460 (1997)]. The aim of this study was to compare direct measurements of forehead tissue oxygenation index (TOI) with the calculated SvO2 during venous occlusion in 16 adult volunteers using a clinical two-channel SRS oximeter (NIRO-300). Measured TOI and calculated SvO2 values of either right or left forehead did not significantly differ. A good agreement between the two NIRS methods was also demonstrated. On 16 other subjects, no significant differences were found between the right and left forehead TOI values measured simultaneously, and between the TOI values measured by channel 1 or 2 on the same side. The results confirm that cerebral cortex hemoglobin oxygen saturation, measured directly by the SRS method, reflects predominantly the saturation of the intracranial venous compartment of circulation.     

Validation of pulse oximetry during progressive normobaric hypoxia utilizing a portable chamber.

Validation of pulse oximetry in commercially available normobaric hypoxic chambers (NHC) has not been previously reported. The present study examined the validity of pulse oximetry (SpO2) against direct measurements of arterial oxygen saturation (SaO2) via co-oximetry (AVOXimeter 4000) in 13 young adults age 21.3 +/- 0.6 years. Over a period of 2.5 hrs, the inspired fraction of oxygen inside a NHC (Hypoxico, Inc.) was progressively reduced from 20.9% to 11.5%. Measurements of SaO2 at baseline and at 15, 30, 60, 90, 120, and 150 min during the hypoxic exposures were compared with SpO2 estimates of oxygen saturation (Nellcor 295) using reflectance (RS-10, temporal) and transmission (D-25, finger) sensors. Regression analysis and methods for assessing agreement (bias, b; precision, p) of SaO2 with SpO2 were similar (R2 = 0.92, 0.89; b = 0.016, -0.47; p = 2.47, 3.03; RS-10 and D-25, respectively). When SaO2 < 85%, RS-10 had greater validity than D-25 (R2 = 0.73, 0.56; b = 1.38, 1.13; p = 2.72, 4.34; RS-10 and D-25, respectively). In light of these findings, caution should be exercised when monitoring individuals with pulse oximetry during desaturation episodes below 85%. When employing frequent NHC exposures, a priori validation of SpO2 utilized to assess blood oxygen status appears warranted.     

胶体预扩容与晶体限制性补液对急诊剖宫产产妇血流动力学的影响

目的:探讨胶体预扩容与晶体限制性补液对急诊剖宫产产妇血流动力学的影响。方法:选取2018年9月至2019年9月我院急诊行剖宫产的125例产妇,按照随机数字表法分为两组,其中对照组62例产妇麻醉前30 min内快速静脉滴注6%羟乙基淀粉(130/0.42)0.5 L,随后静脉滴注乳酸林格溶液5 ml?(kg·h)^-1,观察组63例产妇仅静脉滴注乳酸林格溶液5 ml?(kg·h)^-1。术中采用无创心电图仪监测入室时(T0)、麻醉实施后即刻(T1)、切皮前(T2)、胎儿娩出前(T3)、胎儿娩出后(T4)以及术毕即刻(T5)产妇血压、心率情况,并于新生儿分娩后1、5、10 min评估阿氏(Apgar)评分;胎儿分娩后抽取新生儿动脉血,使用血气分析仪分析脐动脉、静脉血气,记录去甲肾上腺素的用量。结果:两组产妇各时间点收缩压、舒张压、心率以及新生儿的Apgar评分、脐动脉和脐静脉pH、剩余碱(Base excess,BE)以及脐静脉静脉氧分压(Partial pressure of oxygen in venous,PvO2)、静脉血氧饱和度(Mixed venous oxygen saturation,SvO2)均无统计学差异(P>0.05)。而观察组脐动脉PaO2、SaO2及甲肾上腺素用量显著高于对照组(P<0.05)。结论:急诊行剖宫产产妇术中行胶体预扩容与晶体限制性可提高脐动脉PaO2、SaO2水平,增加去甲肾上腺素用量,但对产妇血压、心率及新生儿Apgar评分、静脉血气无明显影响。     

俯卧位通气在复杂先天性心脏病患儿延迟关胸术后低氧血症的应用

目的 探讨俯卧位通气在复杂先心病患儿延迟关胸术后低氧血症的应用效果。方法 回顾性分析2017年1月~2018年12月我院行延迟关胸的34例复杂先天性心脏病患儿的临床资料，对低氧血症患儿实行俯卧位通气，比较第1次俯卧位通气前（T1）、俯卧位0.5 h（T2）、俯卧位1 h（T3）、俯卧位2 h（T4）患儿血气指标[氧分压（PaO2）、二氧化碳分压（PaCO2）、动脉血氧饱和度（SaO2）、乳酸（Lac）]变化及生命体征[心率（HR）、动脉血压（ABP）、中心静脉压（CVP）、呼吸频率（RR）、血氧饱和度（SpO2）]变化。结果 T2~T4时间点PaO2、SaO2均较T1升高，PaCO2、Lac均较T1下降，差异有统计学意义（P＜0.05）。不同时间点HR、ABP、CVP、RR比较，差异无统计学意义（P＞0.05）；T2~T4时间点SpO2较T1升高，差异有统计学意义（P＜0.05）。结论 俯卧位通气可改善复杂先天性心脏病患儿的低氧血症，改善血气指标，是临床可行的支持治疗手段。     

Oximetry based on diffuse photon density wave differentials

The quantification of tissue optical properties for calculating blood saturation and hemoglobin concentration using measurements of diffuse photon density waves at some distance away from an intensity-modulated light source, generally requires the determination of the amplitude and phase of this light source. This determination may become a severe impediment for measurements performed in the clinical environment. In this work we extend a self-calibrating methodology developed for constant wave and modulation depth-phase measurements, to include amplitude and phase measurements of diffuse photon density waves. The method uses amplitude and phase changes of intensity modulated light, under the assumption of known index of refraction and invariant reduced scattering coefficient mu's, to quantify the absorption coefficient mu(a) without requiring initial amplitude and phase knowledge. Quantification of the mu(a) at selected time points during a measurement can then be employed to calibrate numerical solutions of the diffusion equation and compute the mu(a) for the remaining time points of the experiment. It is shown that the method is quite insensitive to the knowledge of the exact mu's value so that an assumption on the average mu's value for the tissue measured may be employed. The sensitivity of calculating blood saturation and hemoglobin concentration, as a function of the deviation of the mu's used in the calculation versus the real mu's value is investigated using simulated data. It is also demonstrated that the saturation calculation is especially insensitive to the mu's guess. The performance of the method to quantify blood oxygen saturation and the concentrations of oxy- and deoxy-hemoglobin is examined with experimental measurements at two wavelengths on specially constructed blood model phantoms. To validate the method the measurements are monitored by a time-resolved spectrometer. The method is shown to be accurate to within +/-5% in calculating blood saturation and to within +/-10% in calculating hemoglobin concentration compared to the results obtained with the time-resolved spectrometer and the expected theoretical values.     

Quantitative spatially resolved measurement of tissue chromophore concentrations using photoacoustic spectroscopy: application to the measurement of blood oxygenation and haemoglobin concentration

A new approach based on pulsed photoacoustic spectroscopy for non-invasively quantifying tissue chromophore concentrations with high spatial resolution has been developed. The technique is applicable to the quantification of tissue chromophores such as oxyhaemoglobin (HbO(2)) and deoxyhaemoglobin (HHb) for the measurement of physiological parameters such as blood oxygen saturation (SO(2)) and total haemoglobin concentration. It can also be used to quantify the local accumulation of targeted contrast agents used in photoacoustic molecular imaging. The technique employs a model-based inversion scheme to recover the chromophore concentrations from photoacoustic measurements. This comprises a numerical forward model of the detected time-dependent photoacoustic signal that incorporates a multiwavelength diffusion-based finite element light propagation model to describe the light transport and a time-domain acoustic model to describe the generation, propagation and detection of the photoacoustic wave. The forward model is then inverted by iteratively fitting it to measurements of photoacoustic signals acquired at different wavelengths to recover the chromophore concentrations. To validate this approach, photoacoustic signals were generated in a tissue phantom using nanosecond laser pulses between 740 nm and 1040 nm. The tissue phantom comprised a suspension of intralipid, blood and a near-infrared dye in which three tubes were immersed. Blood at physiological haemoglobin concentrations and oxygen saturation levels ranging from 2% to 100% was circulated through the tubes. The signal amplitude from different temporal sections of the detected photoacoustic waveforms was plotted as a function of wavelength and the forward model fitted to these data to recover the concentrations of HbO(2) and HHb, total haemoglobin concentration and SO(2). The performance was found to compare favourably to that of a laboratory CO-oximeter with measurement resolutions of +/-3.8 g l(-1) (+/-58 microM) and +/-4.4 g l(-1) (+/-68 microM) for the HbO(2) and HHb concentrations respectively and +/-4% for SO(2) with an accuracy in the latter in the range -6%-+7%.     

Critical evaluation of the 'heated-hand-technique' for obtaining 'arterialized' venous blood: incomplete arterialization and alterations in glucagon responses.

In order to test the degree of 'arterialization' and the occurrence of arterio- (or capillary-) venous differences in glucose concentrations for commonly used blood sampling sites (including the retrogradely cannulated dorsal hand vein with application of dry heat to this hand/arm--the 'heated-hand-technique'), oxygen partial pressure (oxygen saturation) and plasma glucose was determined in blood drawn from different venous sites before and after an oral glucose load (75 g). Experiments with and without heating (hot air 68 degrees C) were compared in nine healthy volunteers. Basal pO2 (and oxygen saturation) increased in the order cubital fossa vein less than superficial forearm vein less than dorsal hand vein. Heating raised pO2 by approximately 20 mmHg; P = 0.008) and oxygen saturation (P = 0.008-0.02) at all sites, including those on the contralateral arm. Capillary-venous glucose differences after the glucose challenge were significantly related to the sampling site (P less than 0.0001). They were reduced by approximately 50% in response to heat exposure (P = 0.008-0.011) and could be correlated to pO2-values (r = 0.92; P = 0.01). The lowest capillary-venous glucose concentration difference was measured with the 'heated-hand-technique' (0.4 +/- 0.1 mmol l-1). Heating did not alter integrated incremental glucose (capillary values), insulin, and C-peptide-responses and late, counter-regulatory responses (120-240 min after glucose) of cortisol, growth hormone, and adrenalin. However, the late glucagon response was enhanced (P = 0.011) by heating, concomitant with a significantly reduced 'reactive' decrement in glucose concentrations. In conclusion, the 'heated-hand-technique' provides blood more similar to arterial blood that can be obtained from other venous sampling sites. However, significant residual differences in pO2 and glucose concentrations remain. In addition, altered counter-regulatory hormone responses may occur with heating.     

A system for investigating oesophageal photoplethysmographic signals in anaesthetised patients

The monitoring of arterial blood oxygen saturation in patients with compromised peripheral perfusion is often difficult, because conventional non-invasive techniques such as pulse oximetry (SpO2) can fail. Poor peripheral circulation commonly occurs after major surgery including cardiopulmonary bypass. The difficulties in these clinical situations might be overcome if the sensor were to monitor a better perfused central part of the body such as the oesophagus. A new oesophageal photoplethysmographic (PPG) probe and an isolated processing system have been developed to investigate the pulsatile signals of anaesthetised adult patients undergoing routine surgery. Measurements were made in the middle third of the oesophagus, 25 cm to 30 cm from the upper incisors. The AC PPG signals are sampled by a data acquisition system connected to a laptop computer. The signals recorded correspond to infrared and red AC PPGs from the middle third oesophagus and the finger. Preliminary results from 20 patients show that good quality AC PPG signals can be measured in the human oesophagus. The ratio of the oesophageal to finger AC PPG amplitudes was calculated for the infrared and red wavelengths for each patient. The mean (+/- standard deviation) of this ratio was 2.9 +/- 2.1 (n = 19) for the infrared wavelength and 3.1 +/- 2.4 (n = 16) for the red wavelength. The red and infrared wavelengths used are appropriate for pulse oximetry and this investigation indicates that the mid-oesophagus may be a suitable site for the reliable monitoring of SpO2 in patients with poor peripheral perfusion.     

Effects of altering O2 delivery on VO2 of isolated, working muscle.

Maximal oxygen consumption (VO2 max) and muscle blood flow (Q max) were measured in an isolated gracilis muscle preparation before and after alteration in perfusion pressure (BP), arterial oxygen saturation (SaO2), and hemoglobin concentration (Hb). Q varied directly with BP and inversely with Hb (viscosity) but was unaffected by changes in arterial SaO2. VO2 max varied directly with oxygen delivery under all conditions. These results indicate that VO2 max is normally limited by oxygen delivery rather than any intrinsic limiting of oxygen consumption of the muscle.     

In vivo cerebrovascular measurement combining diffuse near-infrared absorption and correlation spectroscopies

We combine two near-infrared diffuse optical techniques to study variations of blood flow, haemoglobin concentration, and blood oxygen saturation in the functioning rat brain. Diffuse correlation spectroscopy (or flowmetry) monitors changes in the cerebral blood flow, without the use of the principles of tracer clearance, by measuring the optical phase-shifts caused by moving blood cells. Near-infrared absorption spectroscopy concurrently measures tissue absorption at two wavelengths to determine haemoglobin concentration and blood oxygen saturation in this same tissue volume. This optical probe is non-invasive and was employed through the intact skull. The utility of the technique is demonstrated in vivo by measuring the temporal changes in the regional vascular dynamics of rat brain during hypercapnia. Temporal and spatial variations of cerebral blood flow, haemoglobin concentration and blood oxygen saturation during hypercapnia are compared with other measurements in the literature, and a quantitative analysis demonstrating the self-consistency of our combined observations of vascular response is presented.     

Dynamic in vivo response characteristics of three oximeters: Hewlett-Packard 47201A, Biox III, and Nellcor N-100

Pulse oximeters (Biox III, Nellcor N-100) and a transmittance oximeter [Hewlett-Packard 47201A (HP)] were compared for SaO2 measurement and responsiveness during dynamic changes in arterial oxygen saturation and heart rate. Five sleep apnea syndrome patients were studied because they had large oscillations in SaO2 and heart rate in sleep. During sleep, each patient exhibited a series of rapid (18.0 +/- 8.3 s, mean +/- SD) oscillations in oxygen saturation (92.1 +/- 2.6% to 74.2 +/- 7.7%). Oxygen saturation measurements were sampled simultaneously from each oximeter by computer (at 2 Hz). Accuracy was assessed by comparing pulse and transmittance oxygen saturation measurements at the peak and trough of each apnea-related oscillation. Oximeter response was defined in terms of the "delay" or absolute time difference between the pulse oximeters and the transmittance oximeter for the determination of the peak and trough saturations. Linear regression analysis was used to establish accuracy and response relationships between pulse oximeter sensors (reusable ear, reusable digit, disposable digit, and disposable nasal sensors) and the transmittance oximeter sensor (reusable ear sensor). Pulse oximeter response delay was highly correlated with heart rate. Pulse oximeter SaO2 measurement and response characteristics varied considerably with sensor type (disposable, reusable) and sensor location (ear, nose, and digit). One must be aware of these differences in clinical and research application.     

Small-volume frequency-domain oximetry: phantom experiments and first in vivo results

We describe a new method to determine the oxygen saturation and the total hemoglobin content of tissue in vivo absolutely at small source-detector separations (<10 mm). Phase and mean intensity of modulated laser light of various wavelengths was measured at several predetermined source-detector separations in the frequency domain. From these measured quantities, the absorption coefficient was derived using the modified time-integrated microscopic Beer-Lambert law (MBL). In addition, the interaction volume of the photons was determined using a multi-layer Monte-Carlo model of human skin. To evaluate the method, we employed homogenous solid phantoms (consisting of TiO2 particles embedded in resin) with mean scattering and absorbing properties comparable to those of human skin. Furthermore, in vivo measurements were performed in a healthy volunteer to demonstrate that the technique is applicable for the determination of the oxygen saturation and the total hemoglobin content in the skin in vivo. The proposed technique is especially suited for the on-line determination of the oxygen saturation and total hemoglobin content in applications where small applicators are required (e.g., fetal oxygen monitoring sub partu).     

Oxygen saturation in blood during bronchial histamine challenge

The aim of the study was to evaluate whether significant bronchial constriction which is consequence of histamine administration during the bronchial challenge is accompanied by drop in oxygen saturation in blood (SaO2). A practical aim was to answer the question whether monitoring of saturation by pulsoximetry during the bronchial challenge could improve its method. A study was performed in a group of 25 females and males with non-specific bronchial hyperreactivity. Results of this study revealed a statistically significant association between drop in FEV1 caused by administration of histamine and drop in oxygen saturation, and no association between drop in MEF50 and drop in SaO2. Drop in saturation in blood was not high which does not justify supplementary using of pulsoximetry during the bronchial challenge test.     

Post-apneic inhalation reverses apnea-induced sympathoexcitation before restoration of blood oxygen levels.

Sleep apneas acutely increase sympathetic nerve activity (SNA) and thus arterial blood pressure. We hypothesized that after apnea, sympathoexcitation decreases before recovery of blood oxygen levels because of the predominant inhibitory effect respiratory factors exert over sympathetic nervous system activation. Seven healthy subjects were instrumented for arterial oxygen saturation (pulse oximetry, SaO2), leg muscle SNA (microneurography), and arterial pressure (Finapres). Supine subjects breathed 12% oxygen, 3% carbon dioxide, and 85% nitrogen for one min prior to apnea at the end of a normal tidal expiration. We accounted for circulatory delay in SaO2 measurement (5.4 +/- 0.4 s, mean +/- SE) as the time from the termination of apnea to the midpoint of the nadir of SaO2. SaO2 decreased to average 84 +/- 3% over the final 10 seconds of apnea, and recovered only partially to average 87 +/- 3% over the 10 seconds immediately following apnea. End-expiratory apnea increased SNA 14-fold from baseline levels of 217 +/- 37 units/10 seconds to 3063 +/- 442 units/10 seconds. However, SNA decreased to 93 +/- 32 units/10 s during the first 10 seconds after apnea. These findings indicate that sympathoinhibitory effects of respiratory signals, either lung inflation receptors or central respiratory inputs, predominate over sympathoexcitatory inputs from chemoreceptors to produce immediate and complete sympathoinhibition at the termination of a voluntary apnea. Arterial baroreflexes probably also contribute to sympathoinhibition after apnea.     

新型节血型体外循环管路在心脏手术中的应用

目的 探讨通过改良设计个性化针对性订制的高分子材料体外循环节血管路(婴儿与成人型)在心脏外科手术中的应用效果与临床预后.方法 41套针对天津市胸科医院心脏外科手术实际情况设计的新型成人(20套)及婴儿(21套)体外循环管路分别应用于成人及10 kg以下婴儿患者(实验组),与使用原有常规型成人(20套)及婴儿(19套)管路患者(对照组)进行临床使用对比,观察两者在预充量、用血量、主泵泵压、血红蛋白(Hb)、游离血红蛋白(f-Hb)、血小板(Pit)计数、混合静脉血氧饱和度(SvO2)与胶体渗透压(COP)水平、乳酸(Lac)水平、拔气管插管时间及重症监护室(ICU)时间等方面的差异.结果 应用新型节血型管路的成人及婴儿患者分别与应用常规管路的成人及婴儿患者比较,预充总量、婴儿预充用血量、术中用血量及f-Hb水平均显著减少,差异均有统计学意义(P＜0.05);而主泵泵压、Hb、Pit、SvO2与COP、Lac水平、停机改良超滤结束后Hb水平、拔气管插管时间及ICU时间等的差异均无统计学意义(P＞0.05).结论 小型化节血型订制高分子材料体外循环管路在维持正常成人与婴儿体外循环心脏手术中血流动力学、氧合与灌注水平的基础上发挥了积极的降低预充量与血制品用量的作用;同时提高了血液相容性,减少了红细胞的破坏,术中术后各项生理指标稳定,手术预后与安全性良好,在体外循环过程中值得推广.