Objective To explore the application effect of critical full-time nursing combined with improved posture management in patients with chronic obstructive pulmonary disease and respiratory failure(RF)undergoing mechanical ventilation(MV).Methods A total of 61 RF patients with chronic obstructive pulmonary disease admitted to Jiujiang NO.1 People's Hospital from January 2021 to January 2023 were selected as the research objects.According to random number table method,they were divided into control group(30 cases)and observation group(31 cases).Patients in the control group were received critical full-time nursing,while patients in the observation group were received critical full-time nursing combined with improved posture management.The cardiac function,blood gas indexes,clinical indexes,incidence of complications and incidence of ventilator-associated pneumonia (VAP) were compared between the two groups.Results There were no statistically significant differences in left ventricular ejection fraction (LVEF),forced expiratory volume in one second(FEV1),partial pressure of oxygen in arterial blood (PaO2) and partial pressure of carbon dioxide in arterial blood (PaCO2)between the two groups before nursing (P＞0.05).The LVEF,FEV1 and PaO2 of the two groups after nursing were higher than those before nursing,and PaCO2 of the two groups after nursing were lower than those before nursing,and the differences were statistically significant (P＜0.05).The LVEF,FEV1 and PaO2 of the observation group after nursing were higher than those of the control group,and PaCO2was lower than that of the control group,and the differences were statistically significant (P＜0.05).The mechanical ventilation time,ICU stay time and hospitalization time of the observation group were shorter than those of the control group,and the incidence of VAP and complications were lower than those of the control group,and the differences were statistically significant (P＜0.05).Conclusion The application of critical full-time nursing combined with improved posture management in chronic obstructive pulmonary disease and RF patients treated with MV can improve cardiac function and blood gas indexes,shorten the time of mechanical ventilation,ICU admission and hospitalization,and reduce the incidence of complications and VAP,which is worthy of promotion.