The Effection Of Hyperbaric Cabin On Plateau Hypoxia At High Altitude

Part one Testing and effects of the hyperbaric cabin at 2880m altitudeObjective: To test the ability of hyperbaric cabin and observe the effects of the hyperbaric cabin of the oxygenation on rabbit and human at 2880m altitude.Methods: (1) Testing the performance of hyperbaric cabin: Entered hyperbaric cabin and recorded the noise, pressure and temperature before pressurization. Recorded the corresponding time, noise and temperature when the Pressure increased every 0.01MPa untill the pressure reached balance. (2) 20 healthy rabbits were divided into control group and experimental group at random, which were all implemented with endotracheal intubation and carotid arteries indwelling catheter at anesthesia. The arterial blood gas of the control group and experimental group were observed at 0 min and 70min when they were placed at room and hyperbaric cabin after operation. At the same time record the Respiratory rate (RR) and blood pressure (BP). (3) 16 healthy volunteers whose arterial oxygen partial pressure(PaO₂),oxygen saturation(SpO₂),carbon dioxide partial pressure(PaCO₂)and pH (pH) values measured before and 70 minutes after entering hyperbaric cabin (cabin pressure differential of 0.022 Mpa) were observed. Meanwhile, measured ABG,BP,HR,RR.Results: (1) The maximum pressure of hyperbaric cabin was 0.022 Mpa, the intensity of noise fluctuated between 65 and 73.4 dB, when the pressure reached balance, noise retained 66.4±1.67dB. The difference of temperature was about 2.0℃before and after compression.The time was about 190 seconds when the pressure reached balance between the main cabin and the transitive cabin. The decompression time of hyperbaric cabin is about 200 seconds.(2) PaO₂ was rised from 43.46±7.68mmHg to 80.62±7.08mmHg at 70 minutes in experimental group. PaO₂ was rised from 39.25±4.68mmHg to 55.00±8.21mmHg at 70 minutes in control group. PaCO₂, BP and RR did not change significantly also in the testing process in both groups (P>0.05). (3) PaO₂ was rised from 66.24±3.31 mmHg to 97.29±4.16 mmHg at 70 minutes after volunteer entering hyperbaric, PaCO₂ was rised from 33.53±2.89 mmHg to 36.12±3.19 mmHg, pH was decreased from 7.43±0.01 mmHg to 7.41±0.02, RR was decreased from 17.88±1.16/min to 16.53±1.54/min. However BP and HR did not change significantly.Conclusion: (1) The pressure of hyperbaric cabin can reach 0.022 MPa in a short time, while the safety and comfort are good. (2)Hyperbaric cabin could improve PaO₂ of rabbits remarkedly and had no effects on PaCO₂, BP and RR under increasing the pressure of 0.022 MPa. (3)Hyperbaric cabin could improve PaO₂ and PCO₂ of healthy volunteers remarkedly and decrease pH and RR, had no effection on BP and HR under increasing the pressure of 0.022 MPa.Part two Testing and effects of the hyperbaric cabin at 4532m altitudeObjective: To test the ability of hyperbaric cabin and observe the effects of the hyperbaric cabin of the oxygenation at 4532m altitude.Methods: Applying on same way, only are altitude different.Results: (1) The maximum pressure of hyperbaric cabin was 0.02 Mpa, the intensity of noise fluctuated between 63 and 65 dB, when the pressure reached balance, noise retained 55.7±2.89dB. The difference of temperature was about 1.2℃before and after compression.The time was about 150 seconds when the pressure reached balance between the main cabin and the transitive cabin. The decompression time of hyperbaric cabin is about 160 seconds. (2) PaO₂ was rised from 34.75±3.88mmHg to 72.88±8.76mmHg at 70 minutes in experimental group. PaO₂ was rised from 32.25±2.49mmHg to 48.5±4.00mmHg at 70 minutes in control group. PaCO₂, BP and RR did not change significantly also in the testing process in both groups (P>0.05). (3) PaO₂ was rised from 53.44±4.06mmHg to 83.81±4.87 mmHg at 70 minutes after volunteer entering hyperbaric, PaCO₂ was rised from 27.37±1.82mmHg to 29.68±2.52mmHg, pH was decreased from 7.45±0.002mmHg to 7.42±0.016, RR was decreased from 24.89±1.78/min to 21.12±1.45/min, HR was decreased from 89.75±10.61/min to 78.31±6.68/min, however BP and HR did not change significantly.Conclusion: (1) The pressure of hyperbaric cabin can reach 0.02 MPa in a short time, while the safety and comfort are good. (2)Hyperbaric cabin could improve PaO₂ of rabbits remarkedly and had no effects on PaCO₂, BP and RR under increasing the pressure of 0.02 MPa. (3) Hyperbaric cabin could improve PaO₂ and PCO₂ of healthy volunteers remarkedly and decrease pH, HR and RR, had no effection on BP under increasing the pressure of 0.02 MPa.Part three The effects of the hyperbaric cabin on sleep at 4532m altitudeObjective: To investigate the effects of the hyperbaric cabin on arterial oxygen saturation and ventilation in healthy volunteer sleep at 4532m altitude.Methods: Eight healthy volunteer underwent polysomnograpH (PSG) in hyperbaric cabin when it run or not at 4532m altitude respectively by auto-comparison study. Record the SpO₂, AHI, DI, PB.Results: Hyperbaric cabin could improved oxygen saturation ( SpO₂ ) in sleep, SpO₂ was rised from 81.38±1.41% to 91.63±0.92%, apnoea hypopnoea index ( AHI ) was decreased from 9.50±5.18/min to 4.63±3.11/min,desaturation index ( DI ) was decreased from 15.63±6.97/min to 4.50±3.42/min. Periodic breathing (PB) was decreased from 17.25±6.67m to 6.13±6.36m. Conclusion: Hyperbaric cabin can improve oxygen saturation (SpO₂) in sleep, decrease apnoea hypopnoea index (AHI), desaturation index (DI), periodic breathing (PB), and improve sleep ability at 4532m altitude.