MAIN MILITARY MEDICAL DIRECTORATE

OF THE MINISTRY OF DEFENSE
OF THE RUSSIAN FEDERATION

MAIN MILITARY CLINICAL HOSPITAL
OF THE MINISTRY OF DEFENSE
OF THE RUSSIAN FEDERATION
LLC "AKELA-N"

The use of medical xenon in the treatment of acute and chronic pain syndromes 

Pain is one of the primary reasons for seeking medical help. It accompanies the majority of diseases and pathological conditions, and therefore, the relief of pain is one of the most important tasks in the treatment of various diseases.

Due to the variety of mechanisms of pain, the treatment of each patient should be individualized taking into account the disease that caused the pain, and the clinical features of the pain syndrome itself.

On the basis of the pathophysiological mechanism, pain can be classified as nociceptive pain and neuropathic pain. The best drugs which are used to relieve nociceptive pain are simple analgesics and NSAIDs. If the pain is neuropathic, then the drugs of choice are anticonvulsants, antidepressants, opioid analgesics and lidocaine. In the case of mixed pain syndromes, combined therapy is possible and a choice of drugs depends on the representation of the nociceptive and neuropathic components.

Complex therapy with therapeutic doses of xenon results in effective and rapid relief of pain syndrome regardless of the pathophysiological mechanism, affecting all pathogenic mechanisms (central, peripheral, psycho-emotional) of development of pain.

Xenon in discogenic and vertebrogenic pain syndromes

The mechanisms of development pain in the case of degenerative-dystrophic lesions of the spine (osteochondritis with herniated discs, spondylosis, and spondylarthrosis) may vary depending on the localization of the cause of acute pain or exacerbation of chronic pain. Both neuropathic and nociceptive mechanisms are involved in the development of pain in radiculopathy.

To a certain extent, the intensity of the pain depends on the patient's initial psycho-emotional state. In patients suffering from vertebral pain that have the weak type of nervous system and high level of anxiety the presence of frequent but non-severe psychogenic influences is associated with lack of activation of specific sanogenetic mechanisms of response and adaptation. The development of "painful behavior" with a significant decrease in interest in daily activities, social maladjustment and signs of depression has been also seen in this group of patient.

Practical recommendations. Inhalations of xenon-oxygen mixture are carried out in the acute stage of the disease with severe and very severe pain (VAS score more than 80) in combination with traditional complex pathogenic therapy with the use of NSAIDs, small doses of corticosteroids, vasoactive drugs, decongestants, muscle relaxants, and physical therapy. The number of procedures is from 3 to 10 (an average number is 5). The duration of each inhalation is from 15 to 40 minutes (an average of 25). Procedures are performed daily. In the acute phase of the disease, it is possible to conduct up to two procedures per day.

After the first procedure, a positive effect is usually observed in all patients; the effect lasts for 3 - 5 hours with the reduction in pain syndrome by an average of 35-40 scores on the VAS scale, followed by an increase in pain severity by 10-20 units. With repeated procedures the majority of patients (more than 70%) develop reduction in pain syndrome (to a VAS score of 0- 10) and static and dynamic balance disorders; in about 25% of patients pain decreased to a VAS score of 30-40. Complex therapy with inhalations of xenon-oxygen mixture was ineffective in 4% of cases; resistant pain syndrome of varying severity, stable or progressive neurological defect persisted. In these patients sequestered disc herniation was detected by instrumental investigation.

According to our data, the average time to onset of acute pain relief by inhalation of xenon-oxygen mixture was 3.5 days, while for patients who underwent the procedure twice a day, this period was 2.2 days.

The best effect of therapy was observed in patients with the duration of acute or exacerbation of chronic pain syndrome up to 5 days. Apparently, this can be explained by the fact that all stages of the pathological process have not yet been fully formed. The average number of procedures for this category of patients was 4.5.

In patients with pain duration more than 30 days, pain reduction to 0-10 points was achieved after an average of 8 procedures; this is most likely due to chronicity of pain syndrome on the background of the formed pathogenic mechanism of pain, and the development of painful behavior of patients.

Most likely, xenon due to its effect on all the components of the mechanism of pain syndrome, "breaks" the vicious pathological circle through blocking the pathological impulses, and thereby promotes normalization of microcirculation in tissues and metabolic processes, reduces swelling and musculo-tonic manifestations. In addition to the direct impact on conduction and perception of pain, xenon normalizes the psycho-emotional state of patients, reducing the emotional component of pain.

Xenon in the complex treatment of peripheral neuropathic pain

Neuropathic pain is a type of pain that occurs as a result of the pathological excitation of neurons in the peripheral or central nervous system, which are responsible for the reaction to physical damage to the body (ordinary pain). According to redefinition of neuropathic pain, it is "pain arising as a direct consequence of a lesion or disease affecting the somatosensory system" [21]. Such patients often have sleep disturbances and develop depression and anxiety; their quality of life decreases. Treatment of the underlying disease (which is unconditional) does not always lead to the reduction of pain. Neuropathic pain is divided into central (associated with damage to the brain and spinal cord), and peripheral (damage to the peripheral nervous system).

Traditional complex drug therapy includes the use of anticonvulsants of various pharmacological groups (carbamazepines, gabapentins, pregabalins), antidepressants, analgesics, pain relief patches. Inhalations of xenon-oxygen mixture were used in the complex therapy of neuropathic pain in patients with neuralgia of the branches of the trigeminal and occipital nerves in the case of low efficacy of drug treatment or in the case of the development of adverse drug reactions.

Practical recommendations. In the treatment of peripheral neuropathic pain, the concentration of xenon in the inhaled mixture ranged from 25 to 35% and depended on both the severity of the pain syndrome and the individual characteristics of the patient. The duration of inhalations ranged from 5 to 30 minutes. The number of procedures was from 3 to 10 (average - 5), the frequency was determined individually - from one in two days (in the case of new-onset neuralgia of the occipital nerve) to two procedures per day (in severe and frequent painful paroxysms).

As a result of complex therapy with inhalations of xenon-oxygen mixture, up to 30% of patients with trigeminal neuralgia stopped taking anticonvulsants, the rest of the patients reduced the dose by 30-50% in the complete absence of painful paroxysms. Insufficient effect of treatment was observed in the patient with an identified neurovascular conflict (the frequency of painful attacks decreased from 12 to 6 at a daily dose of Lyrica decreased to150 mg).

In all patients with occipital nerve neuralgia painful paroxysms were completely abolished after 3-7 procedures with complete termination of drug therapy.

Conclusion 

The study indicates a high therapeutic efficacy, safety and prospects of using XeMed® in the complex treatment of discogenic, vertebrogenic and neuropathic pain syndromes, as well as tension headaches, medication-overuse headaches and migraines. Xenon as a part of complex pharmaceutical programs leads to a significant reduction or complete relief of pain syndromes. There was also significant shortening treatment duration and reduction in the associated pharmacological load.

Xenon due to its effect on all the components of the mechanism of pain syndrome "breaks" the vicious pathological circle through blocking the pathological impulses, and thereby promotes normalization of microcirculation in tissues and metabolic processes, reduces swelling and musculo-tonic manifestations. In addition to the direct impact on conduction and perception of pain, xenon normalizes the psycho-emotional state of patients, reducing the emotional component of pain.

The inclusion of the course of inhalation procedures of therapeutic doses of xenon in the system of therapeutic, rehabilitation and preventive measures contributes to the rapid and effective relief of pain syndromes of various origins and creates additional motivation to undergo treatment.

The developed method allows to achieve maximum patient safety and comfort for the doctor due to the absence of complications of the procedure, maintenance of verbal contact with the patient and absence of agitation observed at high xenon concentrations.