摘要目的:探讨压力（pressure，P）联合呼吸频率（respiratory rate，RR）对机械通气患者撤机的指导价值。方法:采用单中心、病例对照研究方法，前瞻性收集2017年11月至2019年4月在徐州医科大学附属常熟医院重症监护病房进行有创机械通气至少24 h的患者76例，排除中枢呼吸抑制、原发神经肌肉疾病患者。当患者具备撤机条件后进行自主呼吸试验（spontaneous breath test，SBT）1 h，根据撤机成功与否将患者分为撤机成功组和撤机失败组。收集两组患者临床资料和两组的峰压（peak inspiratory pressure，P peak）、驱动压（driving pressure，DP）、RR，使用独立样本 t检验或Mann-whitney U检验比较两组相关指标的差异；计数资料采用 χ2检验。采用受试者工作特征曲线（ROC）评价相关指标对撤机失败的预测价值。 结果:76例患者均纳入最终分析，其中撤机成功组50例，撤机失败组26例。撤机成功组P peak×RR，DP×RR均明显小于撤机失败组。P peak×RR（cmH 2O·次/min）：291.8±76.5 vs 519.8±108.8（ P<0.01）。DP×RR（cmH 2O·次/min）：131.6±34.2 vs 227.0±47.5（ P<0.01），P peak×RR，DP×RR的ROC曲线下面积（AUC）分别为0.960、0.941；P peak×RR最佳临界值为362 cmH 2O·次/min时，预测撤机成功的敏感度为96.2%，特异度为88.0%，阳性预测值（PPV）为97.8%,阴性预测值（NPV）为80.6%；DP×RR截断值为170 cmH 2O·次/min时，预测撤机成功的敏感度为88.5%，特异度为92.0%，PPV为94.0%，NPV为88.5%。 结论:压力联合呼吸频率可以较为准确地预测机械通气患者撤机成功。

abstractsObjective:To evaluate the performance of the combinative index-a product of pressure (P) and respiratory rate (RR), to predict the outcome of weaning.Methods:Single-center, case-control study method was used to prospectively collect the data of 76 patients who had been mechanically ventilated for at least 24 h in ICU of the Affiliated Changshu Hospital of Xuzhou Medical University from November 2017 to April 2019, excluding the patients with central respiration repression and primary neuromuscular disease. The spontaneous breath test (SBT) was performed for 1 h after the patient was ready to be weaned. All patients were divided into two groups according to whether they were successfully weaned from the mechanical ventilation: 50 cases in the success group and 26 cases in the failure group. Clinical data and values of peak inspiratory pressure (P peak), driving pressure (DP) and RR of two groups were collected. The independent sample t test and Mann-Whitney U test were used for the comparison between the two groups. The differences between enumeration data were assessed by Chi-square test. Finally, receiver operating characteristic (ROC) curve analysis was used to evaluate the predictive value of each index. Results:Of the 76 patients studied, 26 patients failed extubation. The values of P peak×RR and DP×RR in the success group were significantly less than those in the failure group; P peak×RR (cmH 2O·breaths/min): 291.8±76.5 vs 519.8±108.8 ( P<0.01), DP×RR (cmH 2O·breaths/min): 131.6±34.2 vs 227.0±47.5 ( P<0.01). The AUC of P peak×RR, DP×RR was 0.960 and 0.941, respectively. A decrease in P peak×RR index less than 362 cmH 2O·breaths/min had a sensitivity of 96.2%, a specificity of 88.0%, a positive predictive value (PPV) of 97.8% and a negative predictive value (NPV) of 80.6%, to predict successful weaning. A decrease in DP×RR index less than 170 cmH 2O·breaths/min had a sensitivity of 88.5%, a specificity of 92.0%, a PPV of 94.0% and a NPV of 88.5%, to predict successful weaning. Conclusion:The combination of pressure and respiratory rate can accurately predict whether the patients can be successfully weaned from mechanical ventilation.