Recording of a left ventricle assist device electrical current with a neurally adjusted ventilation assist (NAVA) catheter: a small case series.

BACKGROUND: Neurally Adjusted Ventilatory Assist (NAVA) is an adaptive ventilation mode that recognizes electromyographic diaphragmatic activation as a sensory input to control the ventilator. NAVA may be of interest in prolonged mechanical ventilation and weaning, as it provides effort-adapted support, improves patient-ventilator synchronization, and allows additional monitoring of neuromuscular function and drive. Ventricular assist devices (VAD), especially for the left ventricle (LVAD), are increasingly entering clinical practice, and intensivists are faced with distinct challenges such as the interaction between the system and other measures of organ support. CASE PRESENTATION: We present two cases in which a NAVA mode was intended to support ventilator weaning in patients with recent LVAD implantation (HeartMate III®). However, in these patients, the electrical activity of the diaphragm (Edi) could not be used to control the ventilator, because the LVAD current detected by the catheter superposed the Edi current, making usage of this mode impossible. DISCUSSION/CONCLUSIONS: An implanted LVAD can render the NAVA signal unusable for ventilatory support because the LVAD signal can interfere with the recording of electromyographic activation of the diaphragm. Therefore, patients with implanted LVAD may need other modes of ventilation than NAVA for advanced weaning strategies.

Noninvasive Neurally Adjusted Ventilator Assist Ventilation in the Postoperative Period Produces Better Patient-Ventilator Synchrony but Not Comfort.

BACKGROUND: Noninvasive neurally adjusted ventilatory assist (NAVA) has been shown to improve patient-ventilator interaction in many settings. There is still scarce data with regard to postoperative patients indicated for noninvasive ventilation (NIV) which this study elates. The purpose of this trial was to evaluate postoperative patients for synchrony and comfort in noninvasive pressure support ventilation (NIV-PSV) vs. NIV-NAVA. METHODS: Twenty-two subjects received either NIV-NAVA or NIV-PSV in an object-blind, prospective, randomized, crossover fashion (observational trial). We evaluated blood gases and ventilator tracings throughout as well as comfort of ventilation at the end of each ventilation phase. RESULTS: There was an effective reduction in ventilator delays (p < 0.001) and negative pressure duration in NIV-NAVA as compared to NIV-PSV (p < 0.001). Although we used optimized settings in NIV-PSV, explaining the overall low incidence of asynchrony, NIV-NAVA led to reductions in the NeuroSync-index (p < 0.001) and all types of asynchrony except for double triggering that was significantly more frequent in NIV-NAVA vs. NIV-PSV (p = 0.02); ineffective efforts were reduced to zero by use of NIV-NAVA. In our population of previously lung-healthy subjects, we did not find differences in blood gases and patient comfort between the two modes. CONCLUSION: In the postoperative setting, NIV-NAVA is well suitable for use and effective in reducing asynchronies as well as a surrogate for work of breathing. Although increased synchrony was not transferred into an increased comfort, there was an advantage with regard to patient-ventilator interaction. The trial was registered at the German clinical Trials Register (DRKS no.: DRKS00005408).

Preemptive veno-venous ECMO support in a patient with anticipated difficult airway: A case report.

This report presents a case of endotracheal metastasis in which elective veno-venous extracorporeal membrane oxygenation (VV ECMO) was used to undergo tracheal laser-surgery prior to establishment of a definitive airway. Specifically, we describe the respiratory and airway management in an adult patient from the preclinical phase throughout elective preoperative ECMO implantation to postoperative ECMO weaning and decannulation in the Intensive Care Unit. This case report lends further supports to the idea that the extracorporeal membrane oxygenation could be electively used to provide safe environment for surgery in situations where the standard maneuvers of sustaining adequate gas exchange are anticipated to fail.

Sequential use of extracorporeal devices to avoid mechanical ventilation in a patient with complicated pulmonary fibrosis.

Extracorporeal lung assist devices are widely used these days for a growing number of indications. We report the case of a patient managed with three different flow-range devices sequentially, enabling us to avoid mechanical ventilation. Handling and ethics of this approach are discussed.