A multicenter prospective cohort study of 188 neurosurgical patients in six ICUs included three phases: control with conventional spontaneous breathing (SBT), controlled diaphragmatic thickening fraction (DTF), and combined DTF plus diaphragmatic excursion (DE). No significant differences were found in first SBT success (p=0.127) or extubation (p=0.900). Reintubation was significantly more frequent in the control group compared to the DTF and DTF+DE groups (p=0.004). The total time of mechanical ventilation was longer in the control group (p<0.001). ROC analysis showed a stronger predictive value of DTF versus DE, with a limited benefit of the combination (p<0.01). Kappa analysis showed better agreement between SBT and extubation results when stratified by diaphragm (p<0.01). Nurse-performed diaphragmatic ultrasound supports physician-led weaning assessment, reduces reintubation, and shortens ventilation when using DTF.