Internal Jugular Vein Collapsibility Index for Volume Status Assessment in Preeclampsia in Correlation With Normotensive Parturients : a Prospective Observational Cohort Study

Preeclampsia is a hypertensive disorder of pregnancy that remains a leading cause of maternal and perinatal morbidity and mortality worldwide, particularly in low- and middle-income countries. It is characterized by endothelial dysfunction, increased vascular resistance, and fluid imbalance, all of which complicate perioperative management during cesarean delivery. Accurate assessment of intravascular volume status in these patients is critical for guiding fluid therapy, preventing hypovolemia that worsens uteroplacental perfusion, and avoiding fluid overload, which increases the risk of pulmonary edema - a major cause of maternal mortality in severe preeclampsia.

Traditionally, invasive methods such as central venous pressure (CVP) monitoring and pulmonary artery catheterization have been used to estimate intravascular volume and preload. However, these techniques are associated with significant risks, including infection, thrombosis, and procedural complications, making them unsuitable for routine use in obstetric patients. Non-invasive approaches, such as echocardiography and inferior vena cava (IVC) ultrasound, have been explored but have important limitations in preeclamptic parturients due to altered venous compliance, increased intra-abdominal pressure from gravid uterus, and technical challenges in obtaining consistent IVC windows.

Ultrasound assessment of the internal jugular vein (IJV) has emerged as a simple, rapid, and non-invasive and reproducible bedside technique for evaluating intravascular volume status. The IJV reflects central venous dynamics and can provide real-time information on venous collapsibility without the limitations posed by abdominal compression or operator dependency observed with IVC evaluation.

Importantly, preliminary data from previous study demonstrated that preoperative internal Jugular Vein collapsibility index strongly correlated with fluid status of the pregnant females undergoing cesarean section under spinal anesthesia.

Despite its potential, limited data exist regarding the use of IJV-based indices in preeclamptic parturients, we hypothesize that IJV collapsibility index is a reliable marker of volume status and predictor of post-spinal hypotension in pre-eclamptic parturients , where vascular tone and compliance are significantly altered. This study aims to bridge this gap by assessing the internal jugular vein collapsibility index in pre-eclamptic parturients and comparing it with normotensive pregnant women to determine its clinical utility for optimizing perioperative fluid management.

We hypothesize that this study helps to assess intravascular volume of preeclamptic Parturients to avoid hypovolemia or fluid overload which carry serious risk in this type of patients, both of which carry serious risks in this group of patients.

Inclusion criteria

• Singleton parturients from 18 to 40 years old.
• Either normotensive or preeclamptic parturients scheduled for elective cesarean section under neuro-axial block matched for gestational age 28-40 weeks will be included:
• Normotensive group: uncomplicated normotensive pregnancy with systolic blood pressure below 140 mmHg and diastolic blood pressure below 90mmHg without proteinuria.
• Preeclamptic Group: new onset preeclamptic pregnant female with gestational hypertension after 20 weeks of pregnancy diagnosed based on ISSHP Guidelines: systolic blood pressure ≥140 mmHg and/or a diastolic blood pressure ≥90 mmHg, accompanied by one or more of the following:

• Proteinuria (≥300 mg in a 24-hour urine sample)
• Alb/Cr ratio ≥30 mg/mmol,
• Organ dysfunction (renal insufficiency (creatinine level>1.1mg%), liver involvement (liver enzyme levels ≥3 times normal), neurological complications (Headache and blurring of vision) and hematological involvement (thrombocytopenia<100.000)).

Exclusion criteria

• Parturients with pre-existing cardiac & vascular disease affecting blood volume and vascular compliance: (Valvular or congenital heart disease, arrhythmia, previous history of venous thromboembolism, chronic kidney disease, gestational diabetes).
• multiple gestations
• known thyroid disorders or chronic hypertension
• patients with BMI >40 and patients requiring emergency delivery.