Objective To compare the effects of oxygen therapy and local pressurization in alleviating plateau hypoxia at high altitude. Methods Forty-five healthy male soldiers were investigated at an altitude of 3992 meters. The subjects were randomly divided into three groups, ie. an oxygen inhalation group, a single-soldier oxygen increasing respirator ( SOIR) group and a BiPAP group. The oxygen inhalation group was treated with oxygen inhalation via nasal catheter at 2 L/ min. SOIR was used to assist breath in the SOIR group. The BiPAP group were treated with bi-level positive airway pressure ventilation, with IPAP of 10 cm H2O and EPAP of 4 cmH2 O. PaO2, PaCO2, SpO2 and heart rate were measured before and 30 minutes after the treatment. Results There were continuous increase of PaO2 from ( 53. 30 ±4. 88) mm Hg to( 58. 58 ±5. 05) mm Hg and ( 54. 43 ±3. 01) mm Hg to ( 91. 36 ±10. 99) mm Hg after BiPAP ventilation and oxygen inhalation, respectively ( both P lt; 0. 01) . However, the PaO2 of the SOIR group was decreased from( 56. 00 ±5. 75) mm Hg to ( 50. 82 ±5. 40) mm Hg( P lt; 0. 05 ) . In the other hand, the PaCO2 was increased from ( 30. 41 ±1. 51) mmHg to ( 32. 56 ±2. 98) mm Hg in the oxygen inhalation group ( P lt; 0. 05) , declined from( 28. 74 ±2. 91) mm Hg to ( 25. 82 ±4. 35) mm Hg in the BiPAP group( P lt;0. 05) ,and didn’t change significantly from( 28. 65 ±2. 78) mm Hg to ( 29. 75 ±3. 89) mmHg in the SOIR group ( P gt;0. 05) . Conclusions Both BiPAP ventilation and oxygen inhalation can alleviate plateau hypoxia by improving PaO2 at 3992 meter altitude while SOIR has no significant effect.
Objective To explore the efficacy of bi-level positive airway pressure ( BiPAP)ventilation plus plateau exhalation valve ( PEV) combined with respiratory stimulant for the treatment of pulmonary encephalopathy in patients with acute exacerbation of chronic obstructive pulmonary disease( AECOPD) . Methods 70 AECOPD patients with pulmonary encephalopathy were randomly divided into a control group and a treatment group. All patients received BiPAP ventilation and conventional therapyincluding antimicrobial, bronchodilation, and expectorant treatment. In the treatment group, the BiPAP ventilator was connected to PEV additionally, and naloxone and nikethamide were administered for 3 days.Clinical symptoms, blood gas analysis, vital signs, gas leakage conditions, and adverse reactions were recorded. Results Heart rate, respiratory rate, PaCO2 , and APACHEⅡ score were more significantly lower,the time to recover consciousness was shoter, meanwhile PaO2 , SaO2 , pH, and glasgow coma scale were significantly higher in the treatment group compared with the control group( all P lt; 0. 01) . Two cases in the treatment group and 5 cases in the control group received tracheal intubation and invasive ventilation due to treatment failure. Two elderly patients in the control group died in hospital. Conclusion Noninvasive positive pressure ventilation plus PEV combined with respiratory stimulant can significantly improve symptoms, shorten the time to recover consciousness, reduce the rate of endotracheal intubation, and improve hypoxemia and hypercapnia rapidly in AECOPD patients with pulmonary encephalopathy.