Permissive Hypercapnia During One Lung Ventilation: Impact on Right Ventricular Systolic and Diastolic Functions During Lung Resection

Study Overview
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Brief Summary
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Investigators studied 15 patients scheduled for pulmonary resection through thoracotomy. Initial tidal volume (VT) 10ml kg-1 was reduced to 8ml kg-1 after one lung ventilation (OLV) and the rate adjusted to maintain partial pressure of arterial carbon dioxide (PaCO2) 30-35 mm Hg. Data were obtained at: T1, 15 min post establishing OLV with normocapnia, T2, 15 min post establishing OLV with hypercapnia (PaCO2 7.98kPa (60mmHg) and 9.31kPa (70mmHg) and pH >7.1), and T3, 15 min after resuming OLV with normocapnia. One-way repeated measures analysis of variance (ANOVA), with post hoc Dunnet´s test were used for analysis. A P value < 0.05 is considered statistically significant.

Detailed Description
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Investigators studied 15 patients scheduled for elective pulmonary resection through thoracotomy. Patients had a standardized management for thoracotomies. Initial VT 10ml/ kg was reduced to 8ml/kg after OLV and the rate adjusted to maintain PaCO2 30-35 mm Hg. Haemodynamic, respiratory variables and echocardiographic data (Tei index and TAPSE) were obtained at: T1, 15 min post establishing OLV with normocapnia, T2, 15 min post establishing OLV with hypercapnia (PaCO2 7.98kPa (60mmHg) and 9.31kPa (70mmHg) and pH >7.1), and T3, 15 min after resuming OLV with normocapnia. One-way repeated measures ANOVA, with post hoc Dunnet´s test were used for analysis. A P value < 0.05 is considered statistically significant.

Official Title
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Acute Permissive Hypercapnia During One Lung Ventilation: Impact on Right Ventricular Systolic and Diastolic Functions During Lung Resection

Conditions
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Anesthesia

Intervention / Treatment
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* Procedure: Permissive hypercapnia


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: adult >18 yr elective pulmonary resection through thoracotomy. Exclusion Criteria: Patients with pulmonary hypertension (systolic >50mmHg), intracranial hypertension or previous intracranial haemorrhage, pre-existing hypercapnia, co-existing metabolic acidosis, ischaemic heart disease, predicted postoperative FEV1<800 ml or <40% of the expected in pneumonectomy patient in which transesophageal echocardiography was contraindicated or necessary measurements were difficult to assess.

Ages Eligible for Study
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Minimum Age: 18 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: Screening
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: permissive hypercapnia<br>during one lung ventilation, right ventricular function was assessed by TEE and the effect of rising PCO2 appreciated | Procedure: Permissive hypercapnia<br>* During one lung ventilation, right ventricular function was assessed by transesophageal echocardiography (TEE) and the effect of increased carbon dioxide pressure was evaluated<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Right ventricular systolic and diastolic functions measured by Tei index | Tei index and Tricuspid Annular Plane Systolic Excursion (TAPSE) were used to assess both RV systolic and diastolic functions | Intraoperative |