Clinical Study On The Evaluation Of Perioperative Fluid Responsiveness In Geriatric Hip Fracture Patients By Inferior Vena Cava Ultrasonography

Background and Objective:Hip fracture often occurs in the elderly over 60 years old.1.65 million people around the world occur hip fracture every year.With the aggravation of aging population,the number of patients continues to increase at the rate of 25%every year.In addition to the fracture itself,elderly patients with hip fracture are often associated with a variety of other systemic diseases,with huge differences in fluid responsiveness,making the perioperative fluid management very complex;insufficient fluid intake is easy to lead to shock,while excessive fluid intake is easy to induce complications such as heart failure and pulmonary edema.Therefore,the accurate evaluation of perioperative volumetric reactivity is an important guarantee for the surgical safety of elderly patients with hip fracture.However,routine monitoring indicators such as heart rate and blood pressure have been proven to be less sensitive to changes in blood volume,and invasive examinations such as stroke variability（SVV）and transesophageal echocardiography（TEE）can cause serious discomfort and even complications to patients.As a convenient and non-invasive hemodynamic assessment method,ultrasonic measurement of inferior vena cava（IVC）diameter and respiratory variability has the advantages of easy operation,repeatability and low cost,and has been paid more and more attention in intensive care and clinical anesthesia.In order to guide the nursing staff to carry out accurate liquid management for perioperative patients,ultrasonography was used to measure the diameter and respiratory variability of the inferior vena cava and to compare with the results of the gold standard monitored by the FloTrac/Vigileo system in this study.Methods:The subjects of this clinical study were elderly patients over 65 with low-energy hip fracture requiring surgical treatment admitted to the Third Affiliated Hospital of Army Medical University Hospital from August,2017to June,2018.All patients underwent lumbar plexus&sciatic nerve block anesthesia,and underwent artificial femoral head replacement.Preoperative use of bedside ultrasound instrument under the costal margin at the end of the measurement of the inferior vena cava expiratory maximum diameter（IVCe）and the minimum suction at the end of the pipe diameter（IVCi）and calculate the respiration variation degree of inferior vena cava（IVC-RVI）=（IVCe-IVCi）/IVCe x100%,at the same time Vigileo monitoring heart rate（HR）,cardiac output（CO）output,stroke volume（SV）,mean arterial pressure（MAP）,and extract the artery blood gas analysis.After the measurement was completed,8ml/kg of ringer’s acetate solution was input at a constant rate for capacity load test within 30min.IVCe,IVCi and IVC-RVI were measured by ultrasound again after infusion,and heart rate（HR）,cardiac output（CO）,stroke output（SV）and mean arterial pressure（MAP）were monitored by Vigileo.Arterial blood was extracted again for blood gas analysis.According to the definition of fluid responsiveness,the change of stroke output（SV）before and after capacity load test△SV≥15%was defined as positive capacity response group（R group）,and△SV<15%as negative capacity response group（N group）.Independent sample t test was used to compare the differences between the two groups.Pearson correlation analysis was employed to explore the correlation between IVCe,IVCi,IVC-RVI andΔSV.The ROC curve was plotted to evaluate the value of IVCe,IVCi and IVC-RVI in preoperative volume responsiveness of elderly patients with hip fractures,to determine the optimal diagnostic threshold,and to calculate the sensitivity and specificity at that threshold.Results:1.From August,2017 to June,2018,a total of 75 patients aged over 65 with hip fracture were admitted to the Third Affiliated Hospital of Army Medical University Hospital.According to the inclusion and exclusion criteria,60 cases were eligible for inclusion,including 24 male,36female.All were low energy injury.The mean time from admission to hospital was 10.13±18.83 days,and the mean time from admission to surgery was3.48±2.17 days.2.Among the 60 patients included,33 were in the volume reactive positive group（R group）,including 12 males and 21 females,aged 65⁹2 years,with an average age of79.30±8.77 years.There were 27 patients in the negative volume response group（N group）,including 12 males and 15 females,aged 69⁹8 years,with an average age of 83.89±6.61years.There were no statistically significant differences in gender,height,body mass index,preoperative hospitalization time,hypertension,coronary heart disease and other general conditions between the two groups（P>0.05）.There were no statistically significant differences between the R group and the N group in intraoperative access,days of catheter indwelling,postoperative hospitalization time,hospitalization cost,incidence of complications,number of ICU transfers,postoperative days of catheter indwelling,postoperative days of hospitalization and average hospitalization cost（excluding the cost of prosthesis internal fixation materials）（P>0.05）.3.Before the capacity load test,IVCe,IVCi,IVC-RVI and SV were（1.27±0.26）cm,（1.03±0.26）cm,（19.33±9.60）%,（51.05±13.05）%,and after the capacity load test,IVCe,IVCi,IVC-RVI and SV were（1.65±0.32）cm,（1.39±0.28）cm,（15.29±8.57）%,and（61.25±17.23）respectively.There were significant differences in IVCe,IVCi,IVC-RVI and SV before and after the capacity load test（P<0.05）.4.Before the capacity load test,the differences in HR,SBP,DBP,MAP,CO,PCO₂,PO₂,Hct,BE,tHb,and HCO₃^-between the two groups were not statistically significant（P>0.05）.SV in R group was significantly greater than that in N group,and the difference was statistically significant（P<0.05）.There was no statistically significant difference in IVCe between the two groups（P>0.05）,and IVCi in group R was significantly lower than that in group N,while IVC-RVI was significantly higher than that in group N,and the difference was statistically significant（P<0.05）.Group R Lac was significantly lower than group N（P<0.05）.After the capacity load test,there was no significant difference in SBP,DBP,CO,PCO₂,PO₂,Hct,BE,tHb,HCO₃^-between the two groups（P>0.05）,but the heart rate of R group was significantly lower than that of N group,while the MAP and SV were significantly higher than that of N group,the difference was statistically significant（P<0.05）.There was no significant difference in IVCe and IVCi between the two groups,and IVC-RVI in group R was significantly greater than that in group N,with statistically significant difference（P<0.05）.Meanwhile,the train SV in group R was significantly greater than that in group N（P<0.05）.Group R Lac was significantly lower than group N（P<0.05）.Compared with that before capacity load test,HR,SBP,DBP,Lac,PCO₂ and HCO₃^-of the two groups had no change,and MAP,CO and SV of the N group had no change.However,MAP,CO and SV of the R group increased significantly after capacity load test（P<0.05）.IVCe,IVCi,PO₂ and tHb were significantly increased in both groups,while Hct,BE were significantly decreased（P<0.05）.IVC-RVI was also significantly increased in the R group（P<0.05）,while the change of IVC-RVI in the N group was not statistically significant（P>0.05）.5.The Spearman correlation analysis,IVCe、IVCi andΔSV’s related coefficient of r=0.469 and r=0.345 respectively（P>0.05）;IVC-RVI andΔSV correlation coefficients（r=0.508,P<0.01）.6.The area under the ROC curve（AUC）of preoperative volume response predicted by IVCe and IVCi for elderly patients with hip fractures was（0.531±0.077）（95%CI0.380⁰.683,P=0.677）and（0.697±0.069）（95%CI 0.563⁰.831,P=0.009）,respectively.IVC-RVI predicted the area under the ROC curve（AUC）of preoperative volume responsiveness in elderly patients with hip fractures to be（0.882±0.047）（95%CI0.789⁰.974,P=0.000）.IVCe cannot predict volume response of elderly patients with hip fractures,IVCi with 1.12cm as the critical point,55.6%sensitivity and 84.8%specificity,IVC-RVI with 20.94%as the critical point,78.8%sensitivity and 88.9%specificity.Conclusion:As a rapid and noninvasive monitoring method,it is feasible for ultrasonic measurement of the respiratory variability of inferior vena cava to predict the volume responsiveness of geriatric hip fracture patients and can provide guidance for perioperative fluid management.