This case presentation focuses on the hemodynamic alterations due to acute clamping of superior vena cava (SVC) during a right pneumonectomy for lung cancer and on the alternatives for drug administration. In a 71-yr-old female patient without clinical manifestations of SVC syndrome, this large vein was clamped for 22 minutes for patch placement after sudden and unpredictable hemorrhage. The patient became acutely cyanotic and edematous in the face and upper extremities, arterial blood pressure dropped and the venous pressure in the right internal jugular vein was elevated. Drugs for managing the patient were given endobronchially and via an established right atrium line. Postoperatively, no neurologic deficit was noted. This case demonstrates the difficulties for managing patients without superior vena cava syndrome in which acute, non-programmed intra-operative SVC clamping is performed, as this is followed by systemic and brain hemodynamic deteriorations that may lead to bad outcome.