Evaluation of the Effect of Three Different Tidal Volumes on Internal Jugular Vein Collapsibility Index in Hypovolemic Mechanically-Ventilated Patients Before and After Fluid Therapy

Background Objective: The diameter of the internal jugular vein changes with variations in intrathoracic pressure during inhalation and exhalation and this difference increases during hypovolemia. One of the causes of increased intrathoracic pressure in patients under mechanical ventilation is the tidal volume, which can affect the diameter of the internal jugular vein. On this basis, the present study was designed to investigate the effect of tidal volume on the internal jugular collapsibility index. Materials Methods: In this clinical trial, 30 hypovolemic patients under mechanical ventilation were studied and three tidal volumes of 8, 10, and 12 cc/kg were applied to the patients. Subsequently, patients received fluid therapy and the measurements were repeated. Finally, the internal jugular vein diameters and the indices before and after the fluid therapy were measured in the three mentioned tidal volumes. A repeated measures t- test was used to compare the data. Results: The means of the internal jugular collapsibility index in the three tidal volumes of 8, 10, and 12 cc/kg were 27.78 ±8.87, 28.11±10.24, and 29.67±11.72(p=0.577) respectively before fluid therapy. These values were 27.78±8.87, 28.11±10.24, and 29.67±11.72 (p= 0.288) respectively, after fluid therapy. Conclusion: The results of this study showed that the internal jugular collapsibility index does not correlate with the tidal volume in hypovolemic patients and after fluid therapy.