Different loads of inspiratory muscle training in mechanical ventilation weaning: randomized trial

Abstract

Introduction: The IMT (inspiratory muscle trainning) applies a load to the diaphragm and could increase strength and endurance during weaning from mechanical ventilation. Objectives: to verify the load influencing in IMT of weaning patients on MIP (maximal inspiratory pressure), weaning time and power (W). Methods: Prospective, randomized, controlled trial with 3 groups of weaning patients: automatic group (AG), manual group (MG) and intermittent nebulization (IN). The AG and MG groups were trained twice a day with electronic isokinetic equipment, with the maximal tolerated load in AG and in the MG, who scored in Glasglow Come Scale (GCS) was 8 or less, had the load set to 30% of MIP and had daily 10% increases. Training was held until 48 hours without mechanical ventilation. Results: Were selected 132 patients and included 99, 22 in AG, 25 in MG, and 52 in IN group. There was an increase from initial to final MIP for 3 groups (p≤0,001). Weaning time for the AG was 10.91±10.29 days; for the MG 13.04±18.59 days; and for the IN, 13.94±12.71 days (p=0.11). There was reduction in power values in AG (0.37±0.55; 0.25±0.12) and elevation to MG (0.33±0.08; 0.40±0.10) with significant difference (p=0.004). Conclusion: The higher loads of IMT implemented in weaning patients could promotes greater power during IMT, with no significant effect on the MIP and weaning time.