TORONTO Pretreating the skin with a low-power erbium:YAG laser significantly reduced the pain of intravenous cannulation in children in a double-blind randomized trial of 94 patients.
The laser treatment works by removing a small area of the stratum corneum, which allows for rapid absorption of local anesthesia, coinvestigator Dr. Deena Berkowitz explained. Laser pretreatment takes less than 10 seconds, followed by a 5-minute application of topical anesthesia before needle placement. This dramatically reduces the time of transdermal absorption, a limiting factor in the use of topical anesthetics before intravenous cannulation.
The study confirms the results of laser-assisted anesthesia previously reported in 30 healthy adults (Acad. Emerg. Med. 2005;12:8047) and in 61 adult and pediatric emergency department patients (Acad. Emerg. Med. 2006;13:6238).
Dr. Berkowitz and coauthor Dr. Ira T. Cohen of Children's National Medical Center, Washington, randomized 94 children who required intravenous cannulation to laser or sham laser with the Epiture Easytouch erbium:YAG laser prior to lidocaine 4% cream application and IV cannulation.
Pain was assessed on age-appropriate scales including the Wong-Baker FACES Pain Rating Scale and a 10-cm visual analog scale (a 10-point pain scale measured along a vertical or horizontal line). The patients ranged in age from 3 to 18 years, with an average age of 9 years in the laser group and 11 years in the control group.
The average pain of IV cannulation was significantly less for the 47 children treated with the laser than for the 47 children in the control group (2.94 cm vs. 5.36 cm), Dr. Berkowitz reported at the annual meeting of the Pediatric Academic Societies.
The median pain of laser application was 0 in both groups. Satisfaction surveys indicate that significantly more parents of patients enrolled in the laser group reported their children had less pain with IV cannulation after laser treatment than in the control group (72% vs. 38%).
An audience member questioned whether patients or their parents may have anticipated less pain because of the use of an additional treatment prior to cannulation. "These were children who had had IVs before, but we did see some placebo effect in patients and parents," said Dr. Berkowitz.
Audience member Dr. Lei Chen of Yale-New Haven (Conn.) Children's Hospital, said when he and his colleagues tested the device, some patients were troubled by the laser's gun-like appearance and the release of a small puff of smoke.
Wrapping the device in colorful coverings could have alleviated potential anxiety, but hasn't entirely stopped young boys from wanting to pick up the laser and shoot it, although that's not possible without a key, Dr. Berkowitz said. Only one patient in the treatment arm noticed an odor with the laser application, although staff members did remark on it.
Erythema was observed in some patients with lighter skin color, and hypopigmentation in those with darker skin. Finding the 6 mm in diameter area treated by the laser also can be a problem, but she said stickers can ensure that the exact site is identified for needle insertion.
At $2,500 per laser, "the biggest drawback is going to be cost," said Dr. Berkowitz, who said the study lasers were provided by Norwood Abbey Inc. She disclosed no personal conflicts of interest with the company.
Colorful coverings can reduce the gunlike laser device's ability to induce either anxiety or playfulness in children. COURTESY DR. DEENA BERKOWITZ