It is well known that lidocaine injection can be painful, likely secondary to the acidity. A meta analysis published in the Cochrane Database of 23 trials that compared pain during infiltration of buffered or non-buffered lidocaine found that patients receiving buffered lidocaine reported significantly less pain than those who received non-buffered lidocaine. The decrease in pain was greater for patients who received lidocaine with epinephrine but was also present for those who received lidocaine without epinephrine. The authors' conclusion was that "increasing the pH of lidocaine decreased pain on injection and augmented patient comfort and satisfaction". The studies included in this review however were mainly focused on lacerations, carpal tunnel decompression and "outpatient procedures". There were two studies that specifically involved OB/GYN patients; one investigated buffered lidocaine during epidural catheter removal and the other investigated buffered lidocaine during Norplant insertion. Since the Cochrane Review was published, one further gynecologic study investigating buffered lidocaine has been published involving cervical loop excision.