Methods
ADVERSE EVENTS, TUMOUR NECROSIS, HYPERTENSION, BLIND
Patients aged 18–65 years undergoing knee arthroscopy under general anaesthesia were randomly divided into the lidocaine group (L group) and the normal saline group (N group). Patients received an intravenous injection 10 min before tourniquet inflation of either 1.5mg/kg lignocaine made up to 10ml with 0.9 per cent normal saline, or 10ml of 0.9 per cent normal saline. The primary outcome was the incidence of tourniquet hypertension. Secondary outcomes included haemodynamic changes, degree of elevation of blood pressure, changes in serum inflammatory indicators including interleukin 6 and tumour necrosis factor-α, the numerical rating scale, 15-item quality of recovery after surgery, the incidence of adverse events and the duration of hospital stay. Randomization was computer-generated with allocation concealment by sealed envelopes. Patients, caregivers and researchers were all blind to the allocation group throughout the study.