Correlation of Inferior Vena Cava diameter and IVC Collapsibility Index with Central Venous Pressure (CVP) in critically ill surgical patients

Introduction: Central Venous Pressure is a valuable parameter in the management of critically ill surgical patients in the ICU. Non-invasive methods to extrapolate the volume status of the patient can aid clinicians in expediting proper treatment. The objective of this study is to find a correlation between Inferior Vena cava (IVC) diameter and collapsibility index (CI) with Central venous pressure (CVP) in critically ill surgical patients. Methods: This cross-sectional study included 60 critically ill patients from September 2020 – 31st February 2021. We recorded the patient's age, sex, heart rate, blood pressure, CVP, volume status, IVC minimum, and maximum diameter. After taking consent and explaining the procedure to the patient, the maximum IVC anteroposterior diameter was noted at the end of inspiration and end of expiration in centimeters. IVC collapsibility index was calculated using the formula ([IVCdmax-IVCdmin]/IVCdmax*100%). Following this, the CVP of the patient was measured. Results: Among the patients evaluated, 32 were females. The mean age of the participants was 44.90 ± 15.76 years. The mean central venous pressure maintained was 11.10 ± 2.11cm H2O with an inferior vena cava collapsibility index of 29.69 ± 8.75. There was a negative correlation between CVP and IVC collapsibility index (%), which was statistically significant (r = -0.701, n = 60, p < 0.01). A strong positive correlation between CVP and maximum IVC diameter (r = 0.712, n = 60, p < 0.01) and minimum IVC diameter (r = 0.796, n = 60, p < 0.01) was found. Conclusion: Inferior Vena Cava diameter and IVC Collapsibility Index can be used as a reliable substitute to central venous pressure to determine the patient's volume status.

Ultrasonographically derived caudal vena cava parameters acquired in a standing position and lateral recumbency in healthy, lightly sedated cats: a pilot study

Objectives The aim of this study was to determine the feasibility of ultrasonographically measuring the caudal vena cava (CVC) at the subxiphoid view of healthy, lightly sedated cats in a standing position and lateral recumbency. Methods This was a prospective, observational, experimental single-centre study. Twenty healthy research-purposed cats were enrolled. Two trained operators scanned each cat in two positions – standing and lateral recumbency – in a randomised order. CVC diameter was measured at the narrowest diameter during inspiration and at the widest diameter during expiration, at two anatomical locations along the CVC – where the CVC crosses the diaphragm (base) and 2 mm caudal to the diaphragm. The CVC collapsibility index (CVC-CI) was calculated for each site. Normalcy was assessed with a Shapiro–Wilk test. A one-way ANOVA with post-hoc Tukey’s test was used to compare inspiratory with expiratory values within and between groups. A paired t-test compared the CVC-CI between groups ( P ⩽0.05 indicated statistical significance). Spearman’s correlation and Bland–Altman analysis assessed inter-operator variability. Results All ultrasonographic data passed normalcy and were reported as mean ± SD. When compared with each other, inspiratory and expiratory values were statistically different for position, location and operator (all P <0.0001). There was no statistically significant difference between lateral recumbency or standing position for inspiratory, expiratory and CVC-CI values. Inter-operator variability was substantial, with operator 2 consistently obtaining smaller measurements than operator 1. The mean CVC-CI in lateral recumbency at the base was 24% for operator 1 and 37% for operator 2. For the same site in standing position, CVC-CI was 27% and 41% for operators 1 and 2, respectively. Conclusions and relevance This pilot study demonstrates that it is possible to ultrasonographically measure the CVC diameter in both lateral recumbency and a standing position in healthy, lightly sedated cats. However, measurements obtained are operator dependent with variability between individuals. Further studies are needed to determine if ultrasonographic CVC assessment will prove helpful in estimating intravascular volume status in cats.

Inferior vena cava collapsibility index as a predictor of fluid responsiveness in sepsis-related acute circulatory failure

Background Assessing fluid responsiveness is the key to successful resuscitation of critically-ill sepsis patients. The use of IVC variation is favored among the dynamic methods of fluid responsiveness assessment in the ICU because it is non-invasive and inexpensive; moreover, it does not demand a high level of training. The aim of this study is to determine the value of the IVC respiratory variability for predicting fluid responsiveness in spontaneously breathing sepsis patients with acute circulatory failure. Results In this prospective observational study, fifty-eight spontaneously breathing sepsis patients admitted in the ICU were enrolled after the approval of the departmental Research Ethical Committee, and the informed written consent had been taken from the patients. Ultrasonographic and echocardiographic parameters were measured “IVC parameters and stroke volume (SV)” with calculation of the inferior vena cava collapsibility index (IVCCI) and cardiac output. These values were obtained before (baseline) and after volume expansion with a fluid bolus. The study showed that twenty-nine patients (50%) were considered to be responders, with an increase in CO by 10% or more after fluid challenge. There was a significant difference between responders and non-responders in baseline IVCCI (p value < 0.001). There were no significant differences between responders and non-responders in terms of demographic and baseline clinical characteristics. Also, there was statistically significantly larger maximum (IVC max) and minimum (IVC min) inferior vena cava diameters before volume expansion in non-responders than in responders with p value 0.037 and 0.001 respectively. The suggested cut off value regarding baseline IVCCI to predict response to fluid infusion is 0.32 with a high chance of response above this figure (a sensitivity of 72.41% and a specificity of 82.76%). Conclusions Inferior vena cava collapsibility index assessment can be a sensitive and a good predictor of fluid responsiveness, being based on a safe and a non-invasive technique compared to other methods such as central venous pressure (CVP) measurement and pulmonary artery catheter insertion.

Ultrasound-Guided Preload Indices during Different Weaning Protocols of Mechanically Ventilated Patients and its Impact on Weaning Induced Cardiac Dysfunction

BACKGROUND: Elevation of the left ventricular (LV) filling pressure can occur during weaning of mechanical ventilation due to increase in LV preload and/or changes in LV compliance and LV afterload. AIM: The aim of the study was to evaluate respiratory changes in internal jugular vein and inferior vena cava during weaning from mechanical ventilation. METHODS: Prospective observational study conducted on 80 consecutive patients. Patients were divided randomly into two groups who met the readiness criteria to start spontaneous breathing trial (SBT) either on pressure support ventilation (PS/CPAP) for 30 min or T-piece for 120 min. Weaning failure was defined as a failed SBT or reintubation within 48 h. Echocardiographic evaluation was done on assisted controlled ventilation and at the end of SBT for preload assessment. RESULTS: Mitral Septal E/E’ Cutoff value ≥6.1 with sensitivity 81% and specificity 84.2%, and AUC 0.73 for predicting weaning failure. IVC distensibility index on CPAP cutoff value ≥66.5% with sensitivity 100% and specificity 68.4%, and AUC 0.85. In Group II, Mitral Septal E/E’ Cut off value ≥5.8 with sensitivity 83% and specificity 90.9%, AUC 0.83, IVC collapsibility index Cut off value ≥45.5% with sensitivity 72% and specificity 86%, AUC 0.73. CONCLUSION: Mitral Septal E/E’ could predict weaning-induced diastolic dysfunction. IVC plays an important role in predicting weaning failure.

Is There an Optimal Positive End-expiratory Pressure to Measure the Internal Jugular Vein Collapsibility Index? A Pilot Study in Mechanically Ventilated Patients

Background: Hemodynamic monitoring its early stabilization is very important in critically ill patients. Evaluating the Internal jugular vein diameter during respiratory cycles by the means of Point-of care ultrasound provides an important, easily available and precise index for monitoring hemodynamic status; a new method which is called Internal Jugular Vein Collapsibility Index (IJV-CI). Any events that alters intrathoracic volumes and pressures may affect this index. In this study we investigate the effects of various levels of positive end-expiratory pressure on this index. Methods: Thirty mechanically ventilated patients were studied. We used three different PEEP levels (0, 5 and 10 cmH2o) and point-of-care ultrasound evaluation of IJV (Internal Jugular Vein) diameter to determine the IJV-CI. The analysis were performed using SPSS V.25.0. Results: Patients were included men (76.6%) and women (33.3%). The mean age of patients was 39.65±3.4 for men and 42.71± 9.34 for women. The IJV-CI were 20.71±11.77 and 24.25±11.46 in PEEP=0 and PEEP=10 cmH20 groups respectively. In 5cmH20-PEEP group median and interquartile range were 16.45(14.8). The IJV-CI in three different PEEP levels were not statistically significantly different. Conclusion: According to the finding of this study, we found no evidence of an optimal PEEP level to measure The IJV-CI.

Can Inferior Vena Cava Diameter and Collapsibility Index Be a Predictor in Detecting Preoperative Intravascular Volume Change in Pediatric Patients?

Background: Inferior vena cava (IVC) ultrasound measurement is a reliable indicator used in the assessment of intravascular volume status. The aim of this study was to evaluate intravascular volume changes in pediatric patients by measuring the IVC diameter and collapsibility index (CI) in children whose oral feeding was restricted preoperatively. Material and Methods: From May 2018 to October 2018, a total of 55 pediatric patients who were scheduled for surgery were included in this prospective, observational, cohort study. Fasting and satiety IVC diameters and CIs of patients were determined by ultrasonographic evaluation twice: in the preoperative preliminary evaluation, when the patients were satiated, and before surgery, during a fasting period of 6–8 hours. Ultra-sonographic data were recorded and compared between fasting and satiety periods. Results: In the grey scale (B-mode), mean IVC diameter was significantly higher when the patients were satiated, compared to the measurements made just before surgery during the fasting period. In the M-mode, the mean IVC diameter was significantly higher only during the inspiratory phase when the patients were satiated, while during the expiratory phase it was detected to be statistically similar. Mean CI was significantly higher in the immediate preoperative period, compared to the assessment made when satiated. Conclusion: Preoperative ultrasound IVC diameter and CI measurement can be a practical and useful method for evaluating preoperative intravascular volume in children.

Focused ultrasound of the caudal vena cava in dogs with cavitary effusions or congestive heart failure: A prospective, observational study

Introduction Ultrasonographic indices of the inferior vena cava are useful for predicting right heart filling pressures in people. Objectives To determine whether ultrasonographic indices of caudal vena cava (CVC) differ between dogs with right-sided CHF (R-CHF), left-sided CHF (L-CHF), and noncardiac causes of cavitary effusion (NC). Materials and methods 113 dogs diagnosed with R-CHF (n = 51), L-CHF (30), or NC effusion (32) were enrolled. Seventeen of the R-CHF dogs had pericardial effusion and tamponade. Focused ultrasound was performed prospectively to obtain 2-dimensional and M-mode subxiphoid measures of CVC maximal and minimal size (CVCmax and CVCmin), CVCmax indexed to aortic dimension (CVC:Ao), and CVC collapsibility index (CVC-CI). Variables were compared between study groups using Kruskal-Wallis and Dunn’s-Bonferroni testing, and receiver operating characteristics curves were used to assess sensitivity and specificity. Results All sonographic CVC indices were significantly different between R-CHF and NC dogs (P < 0.001). Variables demonstrating the highest diagnostic accuracy for discriminating R-CHF versus NC were CVC-CI <33% in 2D (91% sensitive and 96% specific) and presence of hepatic venous distension (84% sensitive and 90% specific). L-CHF dogs had higher CVC:Ao and lower CVC-CI compared to NC dogs (P = 0.016 and P = 0.043 in 2D, respectively) but increased CVC-CI compared to the R-CHF group (P < 0.001). Conclusions Ultrasonographic indices of CVC size and collapsibility differed between dogs with R-CHF compared to NC causes of cavitary effusions. Dogs with L-CHF have CVC measurements intermediate between R-CHF and NC dogs.

Inferior Vena Cava Collapsibility Index: A Precise Non-invasive Tool for Evaluation of Edema in Children with Nephrotic Syndrome.

Evaluating the volume status in children with Idiopathic nephrotic syndrome (INS) is mandatory to guide treatment and avoid unnecessary possibly hazardous albumin use. This study aimed to evaluate and compare the available tools used for volume status assessment and differentiating type of edema in children with INS. Sixty children with active INS were included and subdivided into hypovolemic and non-hypovolemic groups based on fractional excretion of sodium (FeNa%) and clinical assessment. All patients were studied for Inferior vena cava collapsibility index (IVCCI), plasma atrial natriuretic peptide (ANP) concentration and Body composition monitor (BCM). Forty-four patients (77.3%) had non-hypovolemic and 16 (26.7%) had hypovolemic states. Plasma ANP levels didn’t differ between hypovolemic and non-hypovolemic subgroups. IVCCI was higher in hypovolemic group (p<0.001) with sensitivity 87.5% and specificity 81.8% for hypovolemia detection while BCM-over hydration (BCM-OH) values were higher in non-hypovolemic group (p=0.04) with sensitivity= 68.2% and specificity =75% for detection of hypervolemia. FeNa% showed negative significant correlation with IVCCI (r= -0.578, p <0.001) and positive significant correlation with BCM-OH (r= 0.33, p=0.018), while FeNa% showed non-significant correlation to plasma ANP concentration (p=0.25). Conclusion: Non-hypovolemic edema is more frequent in edematous INS children than hypovolemic states. IVCCI is a reliable non-invasive bedside tool for evaluating volume status in INS children and is superior to BCM while plasma ANP levels can’t discriminate type of edema in INS.