July, 2007

THEY SAY THE PAIN CAUSED BY KIDNEY STONES is the closest a man can come to the pain of labor and delivery. Unfortunately, about a third of lithotripsy patients — men and women alike — experience excruciating pain like this during the first postoperative day, as byproducts and small stones pass through the urinary system. That's why we offer paravertebral blocks to our patients who undergo ureteroscopic laser lithotripsy and extracorporeal shock wave lithotripsy (ESWL). With this block, even patients who continue to pass small stones do so pain-free.

Paravertebral blocks, which we also use for breast surgery, thoracotomy incisions, cholecystectomy, nephrectomy, and inguinal herniorraphy, take just 5 to 10 minutes to perform. The key is to administer them in a way that avoids pneumothorax.

Our technique involves carefully directing the needle caudally, using the transverse process of each targeted vertebrae as a landmark. Using a seeking current of 2 mA, we first insert a stimulating needle until it contacts the transverse process. We then withdraw and redirect it caudally approximately 0.5 cm past the process until we can elicit an intercostal motor response, or at least a subjective sensation of muscle contraction. After reducing the current to 0.8 mA, we inject 5 mL of 0.5 percent ropivacaine plus epinephrine at each targeted level. If needed, we sometimes use ultrasound before injection as a way to “scout out” the location of the transverse process and estimate the depth to the paravertebral space.

Patients who do not get blocks and who experience pain after outpatient lithotripsy require morphine and oral opioids. As a result, they stay in our PACU for at least two hours. With paravertebral nerve blocks, however, all of our patients to date have been both pain- and opioid-free, and they leave the facility sooner, typically within 60 to 75 minutes after surgery. Even those who pass small stones and postoperative “sludge” at home report no pain. Most importantly, these patients feel good about their surgical experience and return to their normal routine almost immediately.

Dr. Jamieson is a practicing anesthesiologist with Wayne County Anesthesia Associates, Goldsboro, N.C. He performs regional anesthesia procedures at the Wayne Memorial Hospital in Goldsboro.