Correlation between respiratory parameters P0.1 and Pmus and clinical outcomes in patients under invasive mechanical ventilation

<bold>Objectives:</bold> To analyze the correlation between P0.1, Pmus, and clinical outcomes in patients undergoing invasive mechanical ventilation (IMV) for more than seven days. <bold>Methods:</bold> A clinical, prospective, observational study was conducted in the ICUs of a tertiary hospital between May 2022 and December 2023. Measurements of P0.1 and Pmus were taken in patients under IMV for seven days or more during spontaneous breathing trials in the ventilator weaning process. <bold>Results:</bold> Forty-four patients were included, with a mean age of 56±17 years, and a male predominance (52.3%). The mean duration of IMV and ICU stay was 21.48±11.82 days and 30±17 days, respectively. Forty-eight percent of patients were extubated, and 38.1% were reintubated (x²<0.001). There was no significant difference in P0.1 values (p=0.288) and Pmus values (p=0.879) between extubated and non-extubated patients. There was a significant difference in P0.1 values between reintubated and non-reintubated patients (p<0.001), and a strong correlation between predictors (Pearson's R 0.550, p<0.001) and a significant correlation between P0.1 and Pmus values (F=13.4, p<0.001; R² 0.302). From this sample, it was possible to estimate Pmus values using the formula Pmus = (P0.1) × 2.12 + 5.52. <bold>Conclusions:</bold> This study highlights the importance of P0.1 and Pmus parameters in assessing lung function and weaning, emphasizing the potential of P0.1 as a predictor of reintubation and its significant correlation with Pmus, as well as the ability of P0.1 to estimate Pmus values.