Preoperative Ultrasound-based Protocol for Optimization of Fluid Therapy to Prevent Early Intraoperative Hypotension

"Protocol of the interventional group according to the ultrasonographic findings:~Ultrasound scan 2 hours before surgery:~IVCCI\>40 percent and absence of symmetric anterior 'B-profile' on the lung ultrasound indicate intravenous (IV) fluid therapy: 8 ml/kg of isotonic, balanced crystalloid infusion.~IVCCI≤40 percent AND/OR symmetric anterior 'B-profile' contraindicates further IV fluid therapy.~A 2nd ultrasound scan at 30 minutes before surgery:~IVCCI\>40 percent and absence of symmetric anterior 'B-profile' on the lung ultrasound indicate further IV fluid therapy: 5 ml/kg of isotonic, balanced crystalloid infusion.~IVCCI≤40 percent AND/OR symmetric anterior 'B-profile' contraindicates further IV fluid therapy."