Author Of 1 Presentation
THE IMPACT OF FLUIDS ON THE DIAPHRAGM FUNCTION IN MECHANICALLY VENTILATED LAMBS WITH ARDS
Abstract
Background
Mechanical ventilation in critically ill children may induce diaphragm atrophy and injury. Besides mechanical ventilation other factors may play a role in critical illness associated diaphragm weakness, including fluid overload and PEEP.
Objectives
To assess the effect of a restrictive versus liberal fluid strategy on diaphragm strength, and microcirculation in lambs. In addition, we studied the effects of acute change in PEEP on diaphragm contractility.
Methods
Sixteen healthy mechanically ventilated lambs were treated with oleic acid intravenous infusion to induce an indirect ARDS-model and were randomized to a strict restrictive or liberal fluid strategy. During transvenous phrenic nerve pacing, transdiaphragmatic pressure (Pdi) were recorded using oesophageal and abdominal balloons. A Cytocam-IDF video microscope was used to assess the microcirculation in the diaphragm.
Results
Fluid intake was higher in the liberal versus restrictive group, (39.2±15.4 ml/kg vs 100.1±17.8ml/kg, p<0.0001). Pdi was significant lower in the restrictive group after 6 hours of mechanical ventilation compared to baseline (8.3 cmH2O [IQR;2.1-20.3] vs 17.9 cmH2O [IQR;14.1-27.2], p=0.036). Microcirculatory flow index and number of vessel crossing was not significantly different (p=0.102 and p=0.344) between the groups after 6 hours of mechanical ventilation. Acute increase in PEEP from 5 cmH2O to 15 cmH2O decreased Pdi upon electrical stimulation with 40% (p = 0.043) in the restrictive group and 22% (p=0.028) in the liberal group.
Conclusion
Compared to liberal fluid intake a restrictive fluid regime is associated with impaired in vivo diaphragm function in lambs with ARDS. High levels of PEEP decrease diaphragm function.