Hindlimb withdrawal reflexes evoked by Er:YAG laser and scalpel incisions in rats.

OBJECTIVE

In this study, we assessed the magnitudes of nociceptive withdrawal reflexes evoked by skin and muscle incisions made with steel scalpel and erbium:yttrium-aluminum-garnet (Er:YAG) laser.

BACKGROUND DATA: A few studies have suggested that laser incisions would be less painful than conventional scalpel incisions.

METHODS

Twenty adult male Sprague-Dawley rats were used. Under light barbiturate anesthesia, graded incisions were made into the plantar surface of the animals' hindpaws. Electromyographic (EMG) recordings from a hamstring muscle were used to estimate the nociceptive response.

RESULTS

The mean amplitude of EMG activity was significantly higher during incisions made with steel scalpel than with any of the laser irradiation parameters. All laser irradiation parameters produced similar nociceptive responses.

CONCLUSION

Er:YAG laser incisions may be less painful, albeit considerably slower, than scalpel incisions. Laser incisional pain would be more closely related to the mechanical rather than the thermal effect of laser ablation.