Technical advances in transjugular intrahepatic portosystemic shunts.

A transjugular intrahepatic portosystemic shunt (TIPS) can be created percutaneously with the Palmaz balloon-expandable stent. This article describes a transjugular-only approach with a 16-gauge needle. A functional and efficacious shunt can be achieved in most cases with stent diameters of 8-10 mm. Occasionally, a 12-mm-diameter shunt is necessary for effective variceal decompression. The procedure is considered successful when the portosystemic gradient is lowered to 12 mm Hg or less after stent placement. Hepatic vein stenosis in the shunt outflow can develop after the TIPs procedure. This complication has been treated successfully with additional stent placement. TIPS can undoubtedly be performed successfully and safely with a transjugular-only approach; however, the full impact of TIPS on the treatment of portal hypertension remains to be determined.

Neutralized lidocaine: use in pain reduction in local anesthesia.

The effect of pH neutralization on the pain experienced during intradermal lidocaine administration was investigated in a prospective blind study of 20 adult volunteers. A plain solution (pH congruent to 6.1) and three different buffered solutions of 1% lidocaine (pH values of 6.8, 7.0, and 7.2) were prepared, and a 0.5-mL intradermal injection of each was administered to the volar aspect of the forearm. Pain associated with lidocaine infiltration was rated with a linear visual analogue scale. Solutions with a pH of less than 6.8 (unbuffered lidocaine in this study) predictably produced a burning pain sensation on injection. However, buffering of 1% lidocaine above a pH of 6.8 significantly (P less than .05) reduced the mean quantitative pain estimates compared with the nonbuffered controls.