Anaesthetic procedures
hypoxemia, bradycardia, hypotension
Upon enrolment, the patients arriving at the operation theatre without premedication were given 8 ml kgPNB (femoral and sciatic nerve blocks) was performed under ultrasound guidance combined with a nerve stimulator (MultiStim SENSOR, PAJUNK, Geisingen, Germany). If electrical stimulation of ≤ 0.5 mA elicited a visible motor response in the quadriceps femoris for femoral nerve or in the gastrocnemius for sciatic nerve, approximately 20 ml of ropivacaine hydrochloride (3.5 mg mlDuring inhalation of air, side effects such as hypotension (SBP < 90 mmHg or DBP < 60 mmHg), bradycardia (HR < 55 bpm) and hypoxemia (SpO