Effect Of Hanging The Abdomen Free In Prone Position On The Mechanics Of Respiratory Mechanics

Background:Chronic obstructive pulmonary disease（COPD）COPD is not fully reversible airflow of chronic respiratory disease,characterized by limited is one of the highest morbidity and mortality worldwide disease,currently one of the people’s life can be the prevention and treatment of common disease,frequently-occurring disease,but it serious harm to people’s physical and mental health.Its prevalence to account for around 8.2% of Chinese people over 40 [1],is expected in 2020,the world of COPD mortality from fourth in 1990 rose to 3rd [2].Been proposed in the 1970 s and prone to improve ventilation and oxygenation.The critical care medicine conference on the 29 th,and about 50% to 50% of patients with ARDS after treatment,the use of the prone position ventilation improves arterial oxygen partial pressure,and inhaled oxygen concentration decreased.Prone position ventilation in the treatment of acute respiratory distress syndrome（ARDS）has been recognized by more,Prone position ventilation abroad in recent years there has been a research team began to look to the COPD group.But the results were mostly single center,small sample test,the strength of scientific evidence is insufficient to support the validity of prone position ventilation in the treatment of patients with COPD.In all circumstances the prone position treatment can get the biggest effect foster strengths and circumvent weaknesses,therefore this research compare the prone position under the condition of spontaneous breathing is dangling belly have an impact on respiratory and circulatory dynamics,provide a reference basis for clinic.Objective:To study the effect of hanging the abdomen free in prone position on the mechanics of respiratory and cardiovascular system in chronic obstructive pulmonary disease（COPD）patients and healthy controls Methods:Twelve stable COPD patients and 9 healthy controls were enrolled and randomized to be in the supine position（SP）,prone position with the abdomen hanging free（PAF）and prone position with the abdomen right on the table（PAT）,with each position studied for 10 minutes.NICO,BioZ and respiratory function test electrode were used to monitor respiratory and hemodynamic parameters.Results:（1）Mechanics of respiratory: In healthy controls,trans-diaphragmatic pressure（Pdi）in PAT was significantly higher than that in PAF and SP[（13.5±1.6）vs（11.5±2.2）,（10.1±1.7）cm H₂ O,1 cmH₂O=0.098 kPa,P<0.05];In stable COPD patients,Pdi in PAT was significantly higher than that in PAF and SP[（22.6±2.5）vs（15.6±2.6）,（18.2±3.2）cmH₂O,P<0.05].（2）Mechanics of cardiovascular system: In healthy controls,cardiac index（CI）in SP was significantly higher than that in PAF and PAT [（5.01±0.73）vs（4.26±0.47）,（4.39±0.39）L/（min·m²）,P<0.01];In stable COPD patients,CI in SP was significantly higher than that in PAF and PAT [（4.31±0.45）vs（3.85±0.61）,（3.42±0.59）L/（min·m2）,P<0.01],SVRI in PAT was significantly higher than that in PAF[（1 960.9±307.9）dyn·sec·cm-5·m2 vs（1 701.9±422.5）dyn·sec·cm-5·m2,P<0.05].Conclusion:Hanging the abdomen free in prone position would decrease the Pdi and improve diaphragmatic motion no matter for stable COPD patients or healthy controls,hanging the abdomen free would ease the increase of cardiac load in prone position for COPD patients.