Pre-operative Ultrasonographic Evaluation of the Internal Jugular Vein Collapsibility Index and Inferior Vena Cava Collapsibility Index to Predict Post Spinal Hypotension in Pregnant Women Undergoing Caesarean Section

Summary

Postspinal hypotension (PSH) is common in obstetric anesthesia practice, with an incidence of up to 71 %. PSH can occur precipitously and, if severe, can result in both maternal and fetal/neonatal adverse events. Pregnant women with predelivery hypovolemia are at risk of cardiovascular collapse and the sympathetic blockade may severely decrease venous return. Hence, prevention of PSH is an essential element in obstetric anesthesia and fasting for aspiration prophylaxis may further add up to the hypovolemia for the patients not on maintenance fluids.

Hemodynamic monitoring in obstetric patients has evolved during the last decade, with the development of minimally invasive and noninvasive continuous cardiac output (CO) monitors. Ultrasound (USG) is a method for noninvasive hemodynamic optimization in the ICU and ED, and it may be more helpful than other noninvasive methods. Transabdominal USG measurements of inferior vena cava (IVC) are noninvasive and thus are not associated with complications. USG of the IVC diameter is a useful and easy method for assessing a patient's volume status by calculating the IVC collapsibility index (IVCCI).

Recently, the usefulness of point-of-care ultrasonographic examination, performed by anesthesiologists in real time, for perioperative management has been reported . Ultrasonographic studies have established the utility of measuring the inferior vena cava (IVC) or internal jugular Vein (IJV) for evaluating intravascular volume status .

In particular, IVC diameter and collapsibility, obtained from ultrasonographic measurement, have been demonstrated to be predictors of hypotension after anesthetic administration.

Conditions

• Cesarean Section

Interventions

PROCEDURE

US Internal Jugular Vein Collapsibility Index measurment

Machine A sonosite M-Turbo ultrasound machine will be used for all the examinations. A curvilinear USG probe for IVC imaging (1-5 MHz, 21 mm). The US transducer will be placed on the right side of the neck in the transverse plane over RIJV 2 cm above the sternoclavicular joint. The IJV will be identified by the color flow Doppler and compressibility. Care will be taken not to compress or obliterate the vein by applying minimal pressure. When the whole circumference of the vein will be visible the measurements were done. The recordings will be done for four respiratory cycles. The maximum, minimum AP diameters, and cross-sectional area will be estimated and, from this, corresponding CI will be derived (Maximum diameter or cross-sectional area (CSA)-minimum diameter or CSA/maximum diameter or CSA) ×100%. All the above measurements will be repeated with the head end of patients elevated to 30° position.

PROCEDURE

US Inferior Vena Cava Collapsibility Index measurment

Machine A sonosite M-Turbo ultrasound machine will be used for all the examinations. A linear vascular transuder for IJV imaging (7-13 MHz, 38 mm) will be used. The transducer will be placed in the subxiphoid region in a longitudinal position. IVC measurements will be made just distal to the IVC-hepatic vein junction, approximately 3 to 4 cm distal to the right atrium. The IVC will be identified by Doppler waveform, compressibility and phasic collapse with respiration. The maximum (IVCD) and minimum (IVCD) internal anteroposterior (AP) diameters of the IVC at the end of expiration and inspiration respectively over the same respiratory cycle will be measured. The IVCCI is derived from the equation, IVCCI= (IVCD max -IVCD min)/IVCD max × 100.

Sponsors & Collaborators

• Tanta University

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

20 Years

Max Age

40 Years

Sex

FEMALE

Healthy Volunteers

No

Timeline & Regulatory

Start

2020-10-30

Primary Completion

2020-11-01

Completion

2020-12-01