Value of pressure and respiratory rate in predicting success of weaning from mechanical ventilator in patients / 中华急诊医学杂志

ABSTRACT

Objective: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.