RU2724843C2 - Method of therapeutic recompression of divers - Google Patents

Abstract

FIELD: diving medicine.SUBSTANCE: invention can be used in therapeutic recompression of divers. Pressure chamber is pressurized, maintained under pressure and decompressed. Increase of pressure in the pressure chamber is performed no more than to pressure 0.6 MPa during breathing with an oxygen-helium mixture containing in vol. %: oxygen—28–32, the rest is helium. Holding under pressure is carried out for not more than 180 minutes during breathing with the same mixture, after which decompression is started at rate of 1 m/min to pressure at the first mode stop, on which the air-fallen air is switched from the pressure chamber compartment. Further, the decompression is carried out according to the mode provided that the condition ensuring the body's saturation with inert gases without total supersaturation of tissues in nitrogen and helium.EFFECT: method provides safe treatment of decompression sickness in divers by preventing complications, associated with adverse consequences of prolonged stay of the patients under high pressure due to a certain mode of therapeutic recompression.1 cl, 3 tbl

Description

The invention relates to diving medicine, and in particular to methods for treating moderate and severe forms of decompression illness of divers and is aimed at improving the safety of therapeutic recompression and preventing complications.

Therapeutic recompression (repeated increase in pressure) is a radical method of treatment of decompression sickness and a priority measure for any degree of disease severity. It is carried out in a pressure chamber and includes three stages: increasing the pressure (compression) to a selected value, exposure to the highest pressure (isopression), and then lowering the pressure to normal in a special mode (decompression).

Known methods for therapeutic recompression of divers, which include re-increasing the pressure in the pressure chamber, holding under pressure while breathing air, an oxygen-nitrogen-helium mixture, an oxygen-nitrogen mixture, an oxygen-helium mixture or medical oxygen and decompression in special modes [1-6] .

For the treatment of moderate and severe forms of decompression sickness in Russia, the use of therapeutic recompression regimes No. 2-4 of the Diving Service Rules (PVA Navy-2002) is recommended M., 2002. Part II. - Medical support for divers of the Navy. M: Military Publishing House, 2004 .-- p. 157, which provide for an increase in pressure in the pressure chamber to an air pressure of 0.8-1.1 MPa (modes No. 2-3) and the use of an oxygen-nitrogen-helium mixture under a pressure of 1.1 MPa (mode No. 4) for 2-6 hours. Intersectoral rules on labor protection during diving operations // St. Petersburg: Publishing House. SPbMAPO, 2007. - 178 p.) Also provide for the use of air and an oxygen-nitrogen-helium mixture for therapeutic recompression up to 0.6-1.1 MPa. Overseas recommended treatment recompression modes No. 5, 6 and 8 of the British Navy and modes No. 5a, 6a and 7 of the US Navy, modes No. 2A, 3A of the French Navy (1968), tables Cx30 and 30a of the SOMEX firm, 1976, which stipulate increase in pressure to 0.6-0.8 MPa when breathing air and oxygen [1, 2, 6].

The disadvantages of the known methods in the treatment of decompression illness of moderate and severe forms are a high risk of developing pulmonary oxygen poisoning and nitrogen anesthesia when using these treatment regimens. This is due to the high partial pressures of oxygen and nitrogen during prolonged breathing in the pressure chamber. Pulmonary oxygen poisoning complicates the treatment of decompression sickness, and nitrogen anesthesia makes it difficult to provide assistance to sick divers and divers. High doses of oxygen during treatment slow down the desaturation of body tissues from nitrogen or helium and reduce the effectiveness of therapeutic recompression. In addition, the increased pressure of the gaseous medium in 0.8-1.1 MPa, according to Mathieu D. [7], reducing the size of the gas bubbles, in some cases contributes to their penetration through the pulmonary barrier into the arterial bed, aggravating the clinical course of the disease.

In the treatment of severe decompression sickness, the 5th treatment regimen of the Rules of the Russian Navy Diving Service [3] is used, which provides for the recompression of patients to a pressure of 1.1 MPa when breathing divers with an oxygen-nitrogen-helium mixture containing in vol. %: oxygen - 10, nitrogen 40, the rest - helium, for 60-360 minutes, which has a lower density of the medium and reduces the narcotic effect of nitrogen.

The disadvantage of this method is the low treatment efficiency associated with frequent complications, the long duration of treatment and the risk of pulmonary oxygen poisoning during exposures of 180-360 minutes In addition, this gaseous medium is rarely used due to the high cost of helium and the need to have an expensive life support system on the pressure chamber while maintaining the necessary oxygen-nitrogen-helium medium.

Closest to the claimed subject matter of the invention is a method of therapeutic recompression according to the international leadership of NATO [8]. The method involves recompression at a speed of 60 feet / min (20 m / min) to 165 feet (0.6 MPa), holding under pressure for 30 minutes and decompression to 1 stop 60 feet (20 m) at a speed of 30 feet / min at breathing 50% oxygen-helium mixture in the breathing apparatus and then alternately with air and oxygen with a total decompression time of 454 minutes.

The disadvantage of this method is the use of a hyperoxic 50% oxygen-helium mixture for 30 min at a pressure of 0.6 MPa and then alternately oxygen and air during the decompression mode in the total oxygen doses of 894 units exceeding 1.5 times safe for the occurrence of pulmonary forms of oxygen poisoning (615 units of EDIL) for healthy divers [9]. In the treatment of severe forms of decompression sickness, when resistance to hyperbaric oxygen is significantly reduced, the probability of a convulsive form of poisoning is high [10, 11]. Another disadvantage is the high speed of transition to the first stop, which is 30 ft / min (10 m / min), which, together with a shallow first stop of the regime, causes a pronounced supersaturation of the body’s fluids with helium. Even the use of 100% medical oxygen for breathing throughout the entire subsequent period of decompression does not reduce the risk of relapse.

The objective of the invention is to remedy these disadvantages, namely improving the safety of divers in the treatment of decompression sickness and the prevention of complications.

The problem is achieved in that in the method of therapeutic recompression of divers, including increasing the pressure in the pressure chamber, holding under pressure and decompression, increasing the pressure in the pressure chamber is carried out no more than to a pressure of 0.55-0.6 MPa when breathing with an oxygen-helium mixture containing in about. %: oxygen - 28-32, the rest is helium, exposure to pressure is carried out for no more than 120-180 minutes while breathing the same mixture, after which decompression is started at a speed of 1 m / min to pressure at the first stop of the regime, which switch sick with breathing air from the pressure chamber, while further decompression is carried out according to the regime when the conditions for ensuring the desaturation of the body from inert gases are met without a total supersaturation of tissues with nitrogen and helium.

The use of a 28-32% oxygen-helium mixture under a pressure of 0.55-0.6 MPa for 120-180 minutes with decompression without supersaturation of body tissues with nitrogen and helium increases the safety of the therapeutic recompression method by preventing the adverse effects of prolonged exposure to high increased pressure of 0.8-1.1 MPa (nitrogen anesthesia and oxygen poisoning), lower doses of medications. Improving the safety of treatment is also associated with the use of a small pressure value during recompression (0.55-0.6 MPa) and prolonged exposure (up to 120-180 min), which, according to our studies, is a more important factor in the treatment of decompression sickness by compared to the pressure value. In addition, the use of a diving breathing apparatus when breathing under pressure saves expensive helium.

The method of therapeutic recompression of divers and divers is as follows. The pressure increase in the pressure chamber is carried out at a speed of 0.1-0.2 MPa / min to a pressure of 0.55-0.6 MPa, and holding under pressure is performed for 120-180 minutes At the same time, during compression, holding under pressure and switching to the 1st stop of the decompression mode, patients breathe through the mask with an oxygen-helium mixture containing in vol. %, oxygen - 28-32, the rest is helium, from a diving breathing apparatus. After holding under pressure, decompression begins, with the patients switching at the depth of the first stop to breath with air from the pressure chamber. At the same time, they are switched off from the stationary respiratory system or diving breathing apparatus. Then, further decompression is carried out according to the regime, provided that the conditions for ensuring the desaturation of the body from inert gases are met without the total supersaturation of the tissues with nitrogen and helium.

The method was tested with a positive result in animal model experiments and in trials involving divers. In animal experiments, 70 white rats were used, which were subjected to the reproduction of decompression sickness by a two-minute decompression after 1 hour exposure by air suppression of 0.45 MPa. All animals with moderate to severe decompression sickness were completely cured. Therapeutic recompression included a two-hour exposure under the pressure of 0.6 MPa of air and 28-32% CGS and safe decompression. Control was not only clinical data, but also ultrasonic control of decompression gas formation in the body. Compared with air, when using 28-32% CAGS, the symptoms of decompression sickness disappeared 1.7 times faster than when breathing in air.

The average values of the time of disappearance of symptoms are presented in table 1.

The safety of the therapeutic recompression method was tested in trials involving 12 divers with nitrogen pre-saturation by conducting a test diver descent to determine the resistance of divers to decompression gas formation to a depth of 30 m with exposure

Note: KGS is an oxygen-helium mixture.

60 minutes and non-stop decompression for 63 minutes and the beginning of therapeutic recompression after 30 minutes. Tests were conducted at the experimental base of the Research Institute for Rescue and Underwater Technologies of the Naval Research Center of the Navy "Naval Academy" in February - March 2018. The pressure in the pressure chamber was increased at a rate of 0.2 MPa / min to a pressure of 0.6 MPa and exposure under pressure was performed for 120-180 minutes while breathing through a mask of a diving breathing apparatus with an oxygen-helium mixture containing in vol. %: oxygen - 28-30, the rest is helium, after which decompression was started at a speed of 1 m / min to a pressure at 1 stop of the mode, at which divers were switched to breathing air from the pressure chamber compartment, while further decompression was carried out according to the regime under the condition of providing desaturation of the body from inert gases without total supersaturation of tissues with nitrogen and helium with a total decompression time of 38 h 40 min (Table 2). There was no decompression gas formation, symptoms of decompression sickness and oxygen poisoning among the divers during therapeutic recompression.

Comparative characteristics of the proposed method and the prototype method are presented in table 3.

As can be seen from the data in table 3, the claimed method of therapeutic recompression is absolutely safe, since the exposure at therapeutic pressure is 2-3 hours, which allows you to reliably dissolve gas bubbles and cure symptoms of decompression sickness at a pressure of up to 0.6 MPa. The partial pressures of gases used in the composition of the respiratory mixture do not lead to a toxic effect. Fulfillment of the condition for ensuring the desaturation of the body from inert gases without total supersaturation of tissues with nitrogen and helium during decompression ensures the absence of relapse of the disease.

Implementation of the developed method will increase the safety of treating decompression sickness among divers by preventing the adverse effects of prolonged exposure to patients under high pressure (nitrogen anesthesia and oxygen poisoning), and reducing the doses of medications taken.

The proposed invention is fully ready for use.

List of references:

1. RN Diving manual, 1981.

2. US Navy manual, 2000.

3. The rules of the diving service (PVA Navy-2002) M., 2002. Part II. - Medical support for divers of the Navy. M: Military Publishing House, 2004 .-- 176 p.

4. Application for patent of the Russian Federation No. 98120036 from 09/10/2000.

5. Intersectoral rules on labor protection during diving operations // St. Petersburg: Publishing House. SPbMAPO, 2007 .-- p. 168, 170.

6. Smolin V.V., Sokolov G.M., Pavlov B.N. Decompression sickness. / Ed. V.M. Baranova - Kaliningrad: 2010. - Appendix 1, p. 315-323.

7. Mathieu D. Hyperbaric medicine. - M: Bisom, 2012 .-- p. 202.

8. ADivP (A) / MDivP-2 (A). - Washigton, 2000 .-- pp. H-8-H9.

9. Clark J.M. Oxygen toxicity. // The physiology and medicine of diving, edited by P.B. Bennett and D.H. Elliott. Best Publishing CO, Sun Pedro, 1982, P. 200-238.

10. Yunkin I.P., Nazarkin V.Ya. Some ways to increase the therapeutic effectiveness of therapeutic recompression regimens. // Ensuring safety and improving the effectiveness of diving operations: Abstract. doc. - L: VMEDA, 1973. - S. 57-59.

11. Yunkin I.P., Nazarkin V.Ya. Physiological substantiation of some principles of therapeutic recompression regimens. // Ensuring safety and improving the effectiveness of diving operations: Abstract. doc. - L: VMEDA, 1973, p. 55-56.

Claims (1)

The method of therapeutic recompression of divers, including increasing the pressure in the pressure chamber, holding under pressure and decompression, characterized in that the pressure increase in the pressure chamber is carried out no more than to a pressure of 0.6 MPa when breathing with an oxygen-helium mixture containing in vol. %: oxygen - 28-32, the rest is helium, exposure to pressure is carried out for no more than 180 minutes while breathing the same mixture, after which decompression is started at a speed of 1 m / min to pressure at the first stop of the regimen, where patients are switched to breathing air from the pressure chamber compartment, while further decompression is carried out according to the regime when the conditions for ensuring the desaturation of the body from inert gases are met without the total supersaturation of the tissues with nitrogen and helium.