Estimation of Central Venous Pressure by Echocardiography in Intubated Children in Pediatric Intensive Care

Central venous pressure (CVP) is a parameter used very regularly in pediatric resuscitation units. According to international recommendations, it should be measured during resuscitation of acute circulatory failure, severe head trauma, renal transplantation in low weight children, or to indirectly assess systolic pulmonary artery pressure by the tricuspid leak gradient. The baseline measurement should be performed using a central venous catheter placed at the right atrial outlet. However, in clinical practice, trans-thoracic echocardiography (TTE) is the most widely used hemodynamic examination in PRU because of its simplicity of use and the excellent echogenicity of patients. While this technique allows assessment of CVP in spontaneously ventilated adults, it is not recommended in positively ventilated adults. Similarly, no pediatric study has formally demonstrated that TTE parameters allow reliable estimation of CVP in mechanically ventilated children, who represent a significant proportion of patients hospitalized in PRUs. The investigators therefore propose to validate TTE assessment of CVP in children on MV in PRU.

The investigators wish to carry out a prospective, non-interventional study over 12 months in 6 pediatric intensive care units in France. The main objective will be to study the correlation between the measurement of the collapsibility index, the distensibility index of the inferior vena cava and the ratio of the maximum diameter of the IVC to the diameter of the abdominal aorta with the measurement of the CVP.

When a patient meets the inclusion criteria, oral information and a paper record will be given to the parental authority holders by the investigator or a physician representing the investigator. After a reflection period of at least 3 hours, the non-objection will be sought and noted in the file. The patient will then be managed according to standard ICU care. The CVP measurements and ultrasound parameters, collected as part of the study, must be carried out in succession, without modifying the ventilator settings or the current therapies.

The first step will be to measure the CVP on 3 occasions, at 30 second intervals, checking for the absence of spontaneous respiration or extra systole that has modified the appearance of the curve. The 2nd step will be to perform the cardiac ultrasound with measurements taken 3 times, at 30 second intervals, repositioning the ETT probe each time.

The investigators hypothesize that the cardiac ultrasound allows to estimate the central venous pressure in pediatric patients, intubated and ventilated in positive pressure thanks to the measurement of these parameters. If confirmed, this data would allow validation of CVP estimation via a simple and noninvasive examination in children in VM. Furthermore, according to the recommendations, the examination of CVP via the catheter requires strict criteria on the position of the catheter (in the superior vena cava territory and at the right atrial junction). Estimation of CVP via ultrasound would therefore make it possible to obtain this data in patients whose catheter does not respect the required position, particularly patients with a catheter in the lower territory.