EFFECTS OF TOPICAL NITROGLYCERIN AND INTRAVENOUS LIDOCAINE ON PROPOFOL-INDUCED PAIN ON INJECTION

We performed a randomized, placebo-controlled, double-blind study to c ompare the efficacy of intravenous (IV) lidocaine and topical nitrogly cerin ointment in preventing pain during propofol injection. Nitroglyc erin or placebo ointments were applied to the back of the hand over th e skin area overlying the IV catheter tip; lidocaine was or was not ad ded to the propofol solution. One hundred twenty-four patients were ra ndomly assigned to receive one of four treatments: placebo and plain p ropofol, propofol mixed with lidocaine, nitroglycerin ointment and pla in propofol, and nitroglycerin ointment and propofol mixed with lidoca ine. Hence, there were 31 patients in each treatment group. Patients r eceiving nitroglycerin ointment and plain propofol had the highest inc idence of pain on propofol injection (23 of 31 patients, 74%), and the highest median pain score. Only when lidocaine was added to propofol did it effectively reduce the incidence and severity of pain. Patients aged 50 yr and older had a significantly lower incidence and less sev ere pain. We conclude that lidocaine and age, but not topical nitrogly cerin ointment, are factors associated with a decreased incidence of p ropofol-induced pain.