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

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

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.

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.

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.