Does Low-Level Laser Therapy Have an Antianesthetic Effect? A Review

Abstract

Because local anesthetics are vasodilators, they tend to be absorbed into the bloodstream from the operative field as a result of the vasodilation of peripheral arterioles. To counteract this vasodilation, vasoconstrictive agents are often included in local anesthetic solutions to provide a longer duration of anesthesia. Low-level laser therapy (LLLT) has the same benefits, such as microcirculation activation and more-efficient tissue metabolism, analgesic effects, and vasodilatation. If LLLT is used to prevent pain postoperatively, improvements in local circulation and increased vasodilatation may increase the absorption of a local anesthetic agent. This may reduce the duration of the anesthesia, thereby allowing postoperative pain management to begin sooner. The maximal intensity of pain occurs during the first hours after surgery, when the local anesthetic has worn off. Theoretically, postoperative pain control can be increased with the use of a local anesthetic with a more-prolonged action. If a treatment method has both analgesic and antianesthetic effects, then the method may block its own effects. We review whether LLLT applied postoperatively to operated-on areas has an antianesthetic effect, that is, whether pain in the first hours after surgery was greater for patients who received LLLT than for control patients. Not too much evidence supports the antianesthetic effects of LLLT. However, additional experimental and clinical studies must be performed to investigate the effects of LLLT on the duration of anesthesia.

<b>Interaction between low level laser therapy and anesthesia in wistar rats

“…Discussion LLLT is a useful tool for the therapeutic field, aiming tissue repair (Bossini et al, 2012;Cury et al, 2013;Hussein, Alfars, Falih, & Hassan, 2011;Vasilenko et al, 2010), anti-inflammatory effects (Chen, Huang, Sharma, & Hamblin, 2011;Marcos et al, 2011) and analgesia (Chow et al, 2007;Chow, Johnson, Lopes-Martins, & Bjordal, 2009;Chow, Armati, Laakso, Bjordal, & Baxter, 2011;Eslamian, Shakouri, Ghojazadeh, Nobari, & Eftekharsadat, 2012;Rayegani et al, 2011;Yan et al, 2011). However, Aras et al (2010), in a review study, indicate a possible dubious effect of low power laser associated with anesthetics, since it can help or hinder the effects of anesthesia. Ignatov et al (2005) observed, after irradiating with HeNe laser on snails neurons associated bupivacaine, potassium channel changes, increasing the effect of blocking or decreasing the anesthetic action, according to the use of high or low doses of irradiation.…”

“…On the laser capacity to extend or shorten the duration of the anesthetic effect, both by analgesic effects and by increasing local blood supply, respectively, Aras et al (2010) report that the LLLT has been used to prevent postoperative pain, although some studies indicate positive effects and others report no effect. In this way, these authors emphasize the need for further clinical and experimental research to investigate the effects of LLLT on the duration of anesthesia.…”

“…Pereira, Pinho, Medrado, Andrade, & Reis (2010) irradiated mice with 670 nm, after performing skin lesions, and verified an increased expression of vascular endothelial growth factor (VEGF), increased acute inflammation and vasodilation. Such effect of laser therapy is based on the premise of Aras et al (2010), which may have been observed with regard to the time of awakening of the animal, whereas for the irradiated group the time was significantly lower than that to the control group.…”

“…If anesthetics are injected into an area with large vascular activity, the anesthesic substance is rapidly absorbed, which produces a shorter duration of anesthesia time. Increased local circulation, such as vasodilation produced by LLLT, in both local and systemic way, can increase the uptake of anesthetic agents, reducing the action and duration of anesthesia and stimulating precocious pain in the post-operative period (Aras, Omezli, & Gungormus, 2010). The aim of this study was to assess whether the LLLT, 660 nm, can lower the effect of injectable anesthetics (ketamine associated with xylazine) in Wistar rats, considering that these animals and anesthetics are routinely used in experiments aimed at scientific maturity with a view to future applications in humans.…”

Achilles tendon of wistar rats treated with laser therapy and eccentric exercise

“…Thus, the search for therapeutic procedures that promote faster healing and better quality of tendons has been the purpose of various studies. In this context, low-level laser is a therapy used in tendon injuries, for promoting analgesia 5 , and for stimulating collagen 6 and growth factors synthesis, as well as angiogenesis. According to some authors, the therapy allows faster tissue healing 7 , with appropriate structural organization of collagen fibers 8 .…”