Photobiomodulation for Treatment of Lung Fields Due to Smoke Inhalation, Asthma, and Pulmonary Fibrosis

Light as a restorative and protective therapy for the treatment of injury and disease in veterinary medicine is a concept that has generated increased interest over the last decade due to numerous factors, especially the ability to apply this modality in a non-invasive way that has no detrimental side effects to the patient or negative environmental impact. Laser therapy, or photobiomodulation (PBM) has a beneficial effect on cells and tissues, contributing to a directed modulation of cell behaviors, enhancing the processes of tissue repair and cell proliferation while in parallel also reducing inflammation and pain. All of these effects make PBM a versatile modality for use in many “first-aid” situations such as in treating smoke inhalation, traumatic wounds or burns, acute muscle injuries, and snake bite envenomation cases.

Mitochondria within cells contain chromophores which absorb photons from PBM. The primary chromophore of interest is the enzyme cytochrome c oxidase, which is located in the mitochondrial membrane, and which impacts the activity of various molecules such as nitric oxide (NO), calcium ions, ATP, beneficial reactive oxygen species (ROS), and numerous other signaling molecules . These molecules work together by various pathways to normalize metabolism and regulate proteins that are affected by redox reactions and involved in cellular proliferation and differentiation. Together with cytokines and growth factors, they aid in tissue recovery, collagen synthesis and the reduction of oxidative stress and inflammation.

Studies have reported the anti-inflammatory effects of PBM in different lung diseases, including asthma and chronic obstructive pulmonary disease , , , , as well as in respiratory disease states induced by pollutant exposure . Reducing inflammation and spasm in the lungs, are critical in the cases of smoke inhalation, asthma and pulmonary fibrosis. Companion Animal Health’s recommendations for appropriate dosing in these thoracic disorders with PBM is described below. Initial treatment for hospitalized patients should be performed daily to twice daily with decreasing treatment sessions required as the patient’s clinical signs improve. Continue chronic maintenance therapy (typically one session every 2-4 weeks) is required for those patients with asthma or IPF, as this modality will not completely resolve these conditions.

• Select the “Thoracic Disorders” protocol in your laser. This protocol is intended to treat both sides of the thorax and including the thoracic inlet as described below.
• If you do not have this protocol in your laser software; use Operation Mode and the recommendations below.

Each patient should have the treatment area (entire lung field, both sides) measured as follows: Estimate size using a standard CD/DVD disc (100cm2) as a measuring guide. Estimate the number of CD’s required to cover the area being treated, rounded up to the nearest 100cm2, and use the appropriate setting below in OPERATION MODE on the laser unit:

• Each patient should have the entire thorax treated through the intercostal spaces from both lateral aspects. The large contact handpiece (large ball) is recommended.
• Chronic IPF (idiopathic pulmonary disorder) or Feline asthma should be treated initially through an induction phase of three times weekly treatments (ideally, every other day) until symptoms improve, followed by a transition phase of reduced frequency treatments (twice weekly for two weeks, then once weekly for two weeks, then every other week), leading to a maintenance phase of treatments on a frequency required to maintain effect (usually once every 2-4 weeks).
• If there is no response to the above dosing after several treatments, double the total energy dose (in joules, NOT power/watts) for that patient just as you would for a non-healing wound.

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