Preoperative maximal expiratory pressure is associated with duration of invasive mechanical ventilation after cardiac surgery: An observational study

Intelligent alert system for predicting invasive mechanical ventilation needs via noninvasive parameters: employing an integrated machine learning method with integration of multicenter databases

The use of invasive mechanical ventilation (IMV) is crucial in rescuing patients with respiratory dysfunction. Accurately predicting the demand for IMV is vital for clinical decision-making. However, current techniques are invasive and challenging to implement in pre-hospital and emergency rescue settings. To address this issue, a real-time prediction method utilizing only non-invasive parameters was developed to forecast IMV demand in this study. The model introduced the concept of real-time warning and leveraged the advantages of machine learning and integrated methods, achieving an AUC value of 0.935 (95% CI 0.933-0.937). The AUC value for the multi-center validation using the AmsterdamUMCdb database was 0.727, surpassing the performance of traditional risk adjustment algorithms (OSI(oxygenation saturation index): 0.608, P/F(oxygenation index): 0.558). Feature weight analysis demonstrated that BMI, Gcsverbal, and age significantly contributed to the model's decision-making. These findings highlight the substantial potential of a machine learning real-time dynamic warning model that solely relies on non-invasive parameters to predict IMV demand. Such a model can provide technical support for predicting the need for IMV in pre-hospital and disaster scenarios.

EFFECT OF PREOPERATIVE RESPIRATORY REHABILITATION IN PATIENTS UNDERGOING CARDIAC SURGERY

The aim of the study was to evaluate the effects of preoperative respiratory rehabilitation on functional capacity, length of stay in intensive care unit (ICU), duration of mechanical ventilation (MV) and total hospitalization, as well as to estimate arterial blood gas (ABG) values in patients undergoing cardiac surgery. Nineteen patients were included in the randomized observational study, divided into two groups: group A (intervention) and B (control). Preoperative and postoperative rehabilitation was performed in group A, and only postoperative rehabilitation in group B. Rehabilitation was carried out according to a predefined protocol. We used ABG to evaluate respiratory function, two-minute walk test (2MWT) and sit-to-stand test to assess functional capacity. The following data were obtained from medical documentation: duration of MV, length of stay at ICU, occurrence of postoperative pulmonary complications, and length of total hospitalization in both groups. Significant between-group difference was found for the length of total hospitalization and duration of MV (p<0.05 both). Analysis of the mean values of 2MWT on the last day of hospitalization (p=0.005), sit-to-stand test before surgery (p=0.022) and on the last day of hospitalization (p=0.008) showed statistically significant differences. The length of hospital stay significantly correlated with preoperative rehabilitation in group A (r=0.885; p<0.0001). There was no difference in ABG parameters between the groups. The study showed that preoperative respiratory rehabilitation had an effect on reducing duration of MV and length of total hospitalization, and improved functional capacity.

Preoperative expiratory and inspiratory muscle weakness to predict postoperative outcomes in patients undergoing elective cardiac surgery

BACKGROUND

Few studies have evaluated preoperative respiratory muscle strength as a risk factor for postoperative morbidity and mortality. The objective of this study was to evaluate the association of preoperative inspiratory muscle weakness (IMW) and preoperative expiratory muscle weakness (EMW) with duration of mechanical ventilation, length of stay in the intensive care unit (ICU), incidence of postoperative pulmonary complications (PPCs), and mortality in patients undergoing elective cardiac surgery.

MATERIALS AND METHODS

This was a prospective observational study. Patients admitted for elective cardiac surgery were recruited. Maximal inspiratory and expiratory pressure were measured before surgery. A multivariate regression model was used to adjust for possible confounding variables and test the association of IMW and EMW with the duration of mechanical ventilation, length of stay in the ICU, PPCs, and hospital mortality.

RESULTS

Two hundred and fifty-five patients were included in this study. The presence of IMW was associated with an increase in the duration of mechanical ventilation (P = .012). The presence of EMW was associated with a reduction in the incidence of PPCs (P = .005). IMW had no significant association with length of stay in the ICU, PPCs, or hospital mortality. EMW had no significant association with the duration of mechanical ventilation, length of stay in the ICU, or hospital mortality.

CONCLUSIONS

In patients undergoing elective cardiac surgery, preoperative IMW is associated with the duration of mechanical ventilation while preoperative EMW is associated with a decrease in PPCs.