Value of Pulse Pressure Variations and Corrected Flow Time in Esophageal Doppler as a Predictor of Fluid Responsiveness in Prone Position During Spinal Surgery

Study Overview
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Brief Summary
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In patients under mechanical ventilation, Usefulness of dynamic indices based on the heart-lung interactions for guiding volume resuscitation has been well validated. Recently, validity of pulse pressure variation (PPV) has been also reported to predict fluid responsiveness. Oesophageal Doppler (OED) allows continuous monitoring of several important hemodynamic variables. Of the OED variables, corrected flow time (FTc) has been evaluated and used as a preload index, and has been reported to predict fluid responsiveness. Prone position caused physiologic and hemodynamic changes and influenced the predictability and cut-off values of SVV and PPV for fluid responsiveness. In this prospective controlled study, the investigators evaluated the validity of PPV and FTc as predictors for fluid responsiveness in supine and prone position in patients undergoing posterior lumbar spinal fusion

Conditions
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Elective Posterior Lumbar Spinal Fusion

Intervention / Treatment
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* Device: 1.Esophageal doppler monitor
* Device: 2. philips Intelivue MP70 monitors


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients undergoing elective spine surgery age : > 20 and < 70, 3. Patients expecting intraoperative blood loss more than 10% of estimated blood volume Exclusion Criteria: arrhythmias BMI > 30 kg/m2 valvular heart disease left ventricular ejection fraction < 50% history of lung disease pregnancy foreigner contraindications to esophageal doppler monitoring probe insertion (i.e. oesophageal stent, carcinoma of the oesophagus or pharynx, previous oesophageal surgery, oesophageal stricture, oesophageal varices, pharyngeal pouch, intra-aortic balloon pump, coarctation of the aorta, and severe coagulopathy)

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 69 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: corrected flow time<br> | Device: 1.Esophageal doppler monitor<br>* 1.Esophageal doppler monitor (CARDIO Q®, DELTEX MEDICAL. Brighton, U. K.)-inserted into the esophagus and positioned approximately 35-40 cm from the teeth. The position of OED prove was confirmed by continuously measuring blood flow velocity in the descending thoracic aorta and focused to find the optimum peak velocity and waveform signal.<br>* Other names: 1.CARDIO Q®, DELTEX MEDICAL. Brighton, U. K.;Device: 2. philips Intelivue MP70 monitors<br>* 2.philips Intelivue MP70 monitors (Intellivue MP70, philips medical Systems, Suresnes, France) -a radial arterial cannula was inserted and arterial pressure waveforms were monitored through Philips Intelivue MP70 monitors. In the monitor, PPVauto was displayed in real-time. It based on automatic detection algorithms, kernel smoothing, and rank-order filters.<br>* Other names: 2.intellivue MP70, philips medical Systems, Suresnes, France;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| PPV(Pulse pressure variation) |  | 15 minutes after induction of anaesthesia at the supine position | 
| FTc(corrected flow time) |  | 15 minutes after induction of anaesthesia at the supine position |