Evaluation of the Effects of Fluid Therapy on Respiratory Mechanics

Study Overview
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Brief Summary
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The investigators hypothesize that large doses of fluids used during intraoperative could affect lung parenchyma structure and, consequently, gas exchange and respiratory mechanics. The purpose of this study is to evaluate fluids effects on oxygenation, respiratory mechanics, by using two different solutions: crystalloid or colloid.

Detailed Description
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Inclusion Criteria: patients undergoing elective abdominal, thoracic, vascular surgery minimum age 18 years informed consent Exclusion Criteria: patients with severe cardiomyopathy or severe heart failure history of coagulation disorders patients with severe cardiovascular or respiratory disorders renal insufficiency Respiratory mechanic parameters (i.e., inspiratory peak pressure, plateau pressure, total airway resistance, and static compliance) are obtained .Blood samples are drawn simultaneously from the arterial catheters for gas analysis. Data were collected after induction of anesthesia (T0) after 1 h (T1), 2 h (T2), 3 h (T3) and at the end of surgery. Primary outcome: evaluate the fluids effects on oxygenation, respiratory mechanics Secondary outcome: Incidence of surgery related complications

Conditions
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Mechanical Ventilation Complication, Actual Impaired Fluid Volume

Intervention / Treatment
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* Drug: Group Colloid
* Drug: Cristalloid administration


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients undergoing elective abdominal, thoracic, vascular surgery minimum age 18 years informed consent Exclusion Criteria: patients with severe cardiomyopathy or severe heart failure history of coagulation disorders patients with severe cardiovascular or respiratory disorders renal insufficiency severe liver diseases

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 85 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: Health Services Research
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Cristalloid<br>group cristalloid (ringer lactate) | Drug: Cristalloid administration<br>* Only Ringer Lactate administration<br>|
| Active Comparator: colloids<br>colloid: cristalloid in according to cardiac output | Drug: Group Colloid<br>* Group Colloid: cristalloid 1:2 (gelofusine: ringer lactate)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| effects on oxygenation, respiratory mechanics | Lung compliance (l/cmH20), Airaway resistance (cmH2O/L/sec) and PaO2 will be measured | every 30 minutes till the end of surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of respiratory complications | Complications like acute respiratory failure, pneumonia and ARDS will be recorded | 28 days |