RESUMO
BACKGROUND: Stroke volume variation (SVV) is based on cyclic changes of intrathoracic pressure during respiratory cycle. Thoracotomy and one-lung ventilation (OLV) can lead to changes in airway and intrathoracic pressure. The aim of this study was to determine whether thoracotomy and converting from two lung ventilation to OLV could affect SVV values. METHODS: Thirty patients who were scheduled for pulmonary lobectomy or pneumonectomy requiring OLV were enrolled. Induction and maintenance of anesthesia were performed with propofol and remifentanil via total intravenous anesthesia. Hemodynamic variables including mean arterial pressure (MAP), heart rate (HR), cardiac index (CI), and SVV were measured at intervals of 1 min for 10 min after thoracotomy and OLV, respectively. RESULTS: MAP and HR increased from baseline at intervals between 3 and 10 min and between 4 and 10 min after thoracotomy, respectively (P < 0.001). CI increased between 4 and 10 min (P < 0.001). SVV did not change for 10 min after thoracotomy. After OLV, MAP decreased between 4 and 10 min (P = 0.112). SVV was the highest at 1 min after OLV. It returned to the baseline value at 7 min (P < 0.001). CI decreased between 8 and 10 min after OLV (P < 0.001). CONCLUSIONS: SVV can increase after OLV temporarily. Transient increase of SVV may be considered when fluid responsiveness is predicted by SVV during early period after OLV.