Study On The Accuracy Of Pulse Hemoglobin Monitor In Perioperative Period Of Children And Its Application In Fluid Therapy

This study proved that the non-invasive pulse hemoglobin monitor(SpHb)has a good accuracy and precision in the perioperative application of children,which can provide a reliable reference for preoperative screening and intraoperative blood transfusion and other clinical decision-makings.Continuous monitoring of intraoperative hemoglobin dynamic changes by non-invasive pulse hemoglobin monitor can be used to study the distribution and elimination of infusion fluids and provide guidance for fluid therapy.Part 1:Application of pulse hemoglobin monitor in preoperative evaluation of pediatric day surgery.Objective:To evaluate the accuracy and precision of non-invasive pulse hemoglobin monitor in children during their preoperative assessment(normal range Hb values).Methods:In an observational study,122 non-anemic children(age 4.2±1.6 years)who were scheduled to undergo different surgical procedures under general anesthesia were included.In their preoperative preparations,single invasive blood samples(tHb)were routinely taken following hospital policy and compared to simultaneous non-invasive determinations of hemoglobin(SpHb).The obtained data were statistically processed by Pearson correlation analysis,Bland-Altman consistency analysis and modified hemoglobin error grid analysis.A preoperative invasive value of<9 g/dL would have cancelled surgery and implied further investigations.Results:No PI values ?2%occurred among the subjects.The average value of PI was 4.8%± 2.1%.A Pearson correlation analysis was performed based on 122 paired values of tHb and SpHb and gave a correlation coefficient of 0.58(P<0.001),indicating that the two methods for detecting hemoglobin had good correlation.A Bland-Altman plot showed that the mean bias(accuracy)of the difference between SpHb and tHb was-0.44 g/dL,the standard deviation(precision)of the mean bias was 1.04 g/dL,and the 95%limits of agreement(LOA)was-2.5?1.6 g/dL.A modified hemoglobin error grid showed that the noninvasive device could identify almost all invasive hemoglobin values>9 g/dL.In total,there were 4 false-positive values where noninvasively obtained hemoglobin observations were below while the paired invasive values were above 9 g/dL.Among them 2 cases located in the lower area B,1 case was located in the isthmus of A zone,1 case is located in the lower area C.These four values will have different degrees of influence on clinical decision making,of which the most serious is in area C.Conclusion:Noninvasive pulse hemoglobin monitor(SpHb)has a certain degree of accuracy and precision in the preoperative preparation stage,which can reduce the need of venipuncture in these nonanemic children.Part 2:Application of pulse hemoglobin monitor in children undergoing elective major surgery.Objective:To evaluate the accuracy and precision of non-invasive pulse hemoglobin monitor in the monitoring of elective major surgery in children(low Hb values).Methods:In this study,a total of 35 cases of children undergoing elective major surgery were included and their basic information was recorded.Pre-anesthesia baseline values of SpHb,PI and tHb were recorded.The values of SpHb,PI and tHb were recorded at 30,60 and 90 minutes after anesthesia,and at the end of surgery.The obtained data were statistically processed by Pearson correlation analysis,Bland-Altman consistency analysis and modified hemoglobin error grid analysis.7 g/dL(tHb)was set as the intraoperative blood transfusion threshold.Results:A total of 175 pairs of hemoglobin data were collected,of which 8 pairs were excluded due to PI<2%.Finally,a total of 167 pairs of data were included in the statistical analysis.Pearson correlation analysis showed that the correlation coefficient r=0.92(P<0.0001)between SpHb and tHb,indicating that the two methods for detecting hemoglobin had good correlation.Bland-Altman consistency analysis revealed that the mean bias(accuracy)of the difference between SpHb and tHb was 0.12 g/dL,the standard deviation(precision)of the mean bias was 0.75 g/dL,and the 95%limits of agreement(LOA)was-1.3?1.6g/dL.A modified hemoglobin error grid showed that the noninvasive device could identify almost all invasive hemoglobin values(95%,158/167).In total,there were 2 false-positive values and 7 false negative values.All the 9 data points were distributed in the A and B regions,and no data points were distributed in the C region.These values may influence the clinical decision making of intraoperative blood transfusion to varying degrees,but none of them are very serious.Conclusion:Non-invasive pulse hemoglobin monitor(SpHb)has good accuracy and precision in children undergoing elective major surgery,which can provide real-time and accurate reference for intraoperative blood transfusion and fluid therapy.Part 3:Pulse hemoglobin monitor was used to study the distribution and elimination of intraoperative infusion fluid in children.Objective:Continuous noninvasive Hb data were obtained by pulse hemoglobin monitor(SpHb)to calculate and analyze the distribution and elimination of hydroxyethyl starch(HES)130/0.4 in children in two age groups(1-3 years,4-6 years)under general anesthesia.Methods:A total of 28 children with elective major surgery were included and their basic information was recorded.SpHb value,PI value,SpO2,HR and immediate urine volume were recorded at 16 time points including 0min,10n,20min,30min,40min,50min,60min,60min,70min,80min,90min,100min,110min,120min,4h,the end of the operation,when the infusion of HES 130/0.4 was started.The volumetric expansion process of infusion was analyzed dynamically using the law of conservation of mass.Results:The trend diagram of plasma dilution showed that the degree of blood dilution increased in both age groups,but at the end of the experiment,the degree of dilution was more obvious in the older group(4-6 years old),reaching 15%-20%,with large individual differences.However,there was no statistically significant difference in dilution between the two groups.The mean urine volume graph of the two groups showed that the older children(4-6 years old)produced more urine and the individual difference was more significant,but there was no difference in the mean residence time(MRT)between the two groups.The plot of net volume(infusion minus accumulated urine)shows a turning point 20 minutes after infusion,after which the accumulative rate of net volume becomes slower.Conclusion:Noninvasive pulse hemoglobin monitor(SpHb)has been used for the first time to study volume kineticsin children.The study obtained the plasma dilution curve after intraoperative infusion of HES 130/0.4,and found that both groups(1-6 years old)could produce the expansion effect,and the urine volume of the 4-6 year old group was more and faster than that of the 1-3 year old group after the infusion of the same proportion of HES 130/0.4.It is proved that it is feasible to calculate the fluid distribution and elimination by using non-invasive pulse hemoglobin monitor to continuously monitor the dynamic changes of intraoperative hemoglobin.In addition,analysis of fluid input and urine output may be sufficient to determine the effects of different fluids on blood volume in children.