Respiratory muscle assessment in predicting extubation outcome in patients with stroke

Patients with cerebral infarction often present impaired consciousness and unsatisfactory extubation. We aimed to assess the respiratory mechanics components that might be associated with the success of extubation in stroke patients.

Twenty consecutive patients with stroke who needed mechanical ventilation support were enrolled. The maximal inspiratory pressure, gastric and the esophageal pressure (Pdi/Pdimax), minute volume, respiratory rate, static compliance, airway resistance, rapid and superficial respiration index (RSRI), inspiratory time/total respiratory cycle (Ti/Ttot), and PaO(2)/FiO(2) were measured.

The group who presented success to the extubation process presented 12.5±2.2=days in mechanical ventilation and the group who failed presented 13.1±2=days. The mean Ti/Ttot and Pdi/Pdimax for the failure group was 0.4±0.08 (0.36-0.44) and 0.5±0.7 (0.43-0.56), respectively. The Ti/Ttot ratio was 0.37±0.05 (0.34-0.41; p=0.0008) and the Pdi/Pdimax was 0.25±0.05 for the success group (0.21-0.28; p<0.0001). A correlation was found between Pdi/Pdimax ratio and the RSRI (r=0.55; p=0.009) and PaO(2)/FiO(2) (r=-0.59; p=0.005). Patients who presented a high RSRI (OR, 3.66; p=0.004) and Pdi (OR, 7.3; p=0.002), and low PaO(2)/FIO(2) (OR, 4.09; p=0.007), Pdi/Pdimax (OR, 4.12; p=0.002) and RAW (OR, 3.0; p=0.02) developed mechanical ventilation extubation failure.

Muscular fatigue index is an important predicting variable to the extubation process in prolonged mechanical ventilation of stroke patients.