Evaluation of Corrected Carotid Artery Flow Time as a Predictor of Fluid Responsiveness in Spontaneous Breathing Patients

It is still challenging to assess intravascular volume status in spontaneously breathing patients. Recently, the measurement of corrected flow time in carotid artery was introduced as quite useful, simple and noninvasive for the evaluation of circulating blood volume change. The aim of this study is to evaluate whether corrected carotid artery flow time as determined by ultrasonography can be a predictor of fluid responsiveness in spontaneously breathing patients before induction of general anesthesia.

Inclusion Criteria:

• adult patients (19-80 years of age) who were scheduled to undergo elective neurosurgery for brain tumor

Exclusion Criteria:

• BMI > 35 or < 15 kg/m2
• the presence of carotid artery stenosis > 50%
• systolic blood pressure > 160 mmHg
• cardiac rhythm other than sinus
• intracardiac shunt 6. valvular heart disease
• a left ventricular ejection fraction of < 50%
• right ventricular dysfunction 9
• chronic obstructive pulmonary disease
• pulmonary hypertension
• chronic kidney disease (eGFR < 60 mL/min/1.73m2)
• pregnancy