The Validity of Carotid Doppler Peak Velocity and Inferior Vena Cava Collapsibility Index in Identifying the Fluid Responders in Mechanically Ventilated Septic Shock Patients

Introduction: Measures of carotid artery flow or inferior vena cava diameter were recently shown to predict fluid responsiveness. Both are relatively superficial large vessels which can provide straightforward ultrasound evaluation & high-qualityimages.Methods: Our study is a prospective observational on 30 mechanically ventilated septic shock patients in ICUto assess the responsivenessby measuring Doppler peak velocity&respiratory variation against increase cardiac index by echocardiographic calculations as reference. All given bolus 7 ml/ Kg crystalloid solution within minutes, static and dynamic indices include CVP, MAP, pulse pressure, difference between IVC during inspiration expiration (ΔIVC- d) velocity single respiratory cycle (ΔCDPV) measured before (T0) after (T1). Vasoactive drugs infusion rate ventilation settings did not changed follow up. Patients categorized either responders “R” non-responders “NR” according an output “CO” (increase CO > 15 %.Results: Comparing Non group we found significant Cardiac measures,MAP Δ CDPV pre post boluses (5.26±4.42 L/min Vs. 10.62±5.73 L/min, 69.48±9.70 mmHg 84.90±10.36 mmHg&24.43±11.87%Vs33.22±11.00%) respectively with P-value (0.007, 0.05&0.01) respectively, other side , ΔD-IVC CVP didn’t show any statistical (11.91±9.41 % 13.51±9.56 %, 5.86±5.22 cmH2O Vs 7.22±4.82 cmH2O) (0.87&0.68)respectively.Δ response increased intravascular volume R showed sensitivity 81%, specificity 66.7%. APACHE II, SOFA day 0,5 NR (16.05±3.23 18.44±3.81, 11.48±2.82Vs12.11±2.80& 12.95±3.68Vs12.56±3.97) (0.164, 0.625 0.79) respectively. Conclusion: ΔCDPV was more precise even easier assessment tool better for responsiveness than upon mechanicalventilation. Also, has high correlation SVI increasing parameters assessed echocardiography boluses. On hand comparison, low accuracy predicting responsiveness.