OXYGEN LEAKAGE AROUND THE LARYNGEAL MASK AIRWAY DURING LASER TREATMENT OF PORT-WINE STAINS IN CHILDREN

The flash-lamp pumped pulsed dye laser is the current treatment of cho ice for cutaneous port-wine stains. In our practice, most children wit h these lesions are treated under general anesthesia. At energy levels used clinically, it is possible to ignite hair in the presence of sup plemental oxygen; we are aware of four cases in which either the eyebr ows or eyelashes were ignited during the administration of general ane sthesia via a face mask. The laryngeal mask airway (LMA) recently has become widely available and this device might decrease the risk of fir e during treatment of these lesions. We therefore designed this study to examine the extent of oxygen leakage under the mask during clinical cases, and to compare this with the leakage present with the LMA. A t otal of 20 patients aged 4 mo to 16 yr were studied on 26 separate occ asions. During spontaneous ventilation, high concentrations of oxygen leaked around the mask in every case (mean 63% +/- 16%), but in only o ne case was a concentration more than 21% detected around the LMA (P < 0.001). During controlled ventilation with the LMA, oxygen leaked aro und the mask in 19% of cases. Use of the LMA markedly decreases the in cidence of potential oxygen leakage into the laser field, and is recom mended for use, with preservation of spontaneous ventilation, during t hese cases. We suggest measuring oxygen concentrations at the mouth fo r laser treatment of facial port-wine stains to confirm that the laryn x has been isolated. Anesthesia via a mask with oxygen and nitrous oxi de should not be used while lesions around the eyes are treated, due t o the risk of igniting the eyebrows or eyelashes.