TOPIC: Critical Care
      TYPE: Original Investigations
      PURPOSE: Approximately 60% of patients requiring mechanical ventilation (MV) for COVID-19 are eventually liberated from the ventilator an average of 14–18 days following intubation; however, for some patients MV liberation is delayed. For these patients, weaning from MV represents a race against rapid diaphragmatic muscle atrophy which may lead to long-term MV dependence or death. The Food and Drug Administration (FDA) granted emergency use authorization for a temporary transvenous diaphragmatic neurostimulation (TTDN) system for use during the COVID-19 pandemic (Lungpacer Medical Inc.).6 TTDN involves a temporary central venous catheter introduced throught the left subclavian vein which includes electrode arrays capable of stimulating the phrenic nerves, which is provided from a clinician-operated bedside unit connected to the CVC resulting in contraction of the diaphragm concomitant with assisted ventilation.
      METHODS: Retrospective observational study describing using TTDN among patients with COVID-19 pneumonia and acute respiratory distress syndrome (ARDS) who required MV at the University of Florida Hospital between December 2020 and January 2021. Patients were screened for TTDN use and received transvenous pacing therapy in addition to their standard care. Exclusion criteria included use of paralytics, implanted pacemaker/defibrillator device, body mass index > 45 kg/m2, proning, bacteremia and severe multiorgan failure. Each patient received 1 or 2 sessions of TTDN per day; each consisting of 60 electrical stimulations timed at the end of expiration, administered during assisted volume controlled ventilation or pressure support ventilation, until the patient was liberated from MV or expired. Comparisons were done using nonparametrical tests.
      RESULTS: Eight patients received TTDN in addition to standard of care. Median age was 68.3, and 75% were female. The median body mass index was 30.8. The median time on mechanical ventilation prior to initiation of TTDN was 3.0 (1.8 – 6.0) days, patients received TTDN for a median of 3.0 (2.8 – 6.3) days until liberated from the ventilator or expiring at median day of 8.5 (4.0 – 9.5) days. Six of 8 (75%) patients were liberated from the ventilator while receiving TTDN. Median PaO2 and PaO2/FiO2 ratio improved over the period of TTDN use [82.2 vs 141.5, P<0.05; and 167.3 vs 306.0, P<0.05 respectively]. 6 out of 8 patients were extubated. No complications were associated with catheter placement or therapy.
      CONCLUSIONS: Early clinical feasibility studies have shown an improvement in MIP and RSBI and a trend towards reducing time on MV. Our preliminary experience using TTDN to assist patients with COVID-19 and MV weaning indicates that this novel technology may assist in earlier liberation from MV and appears safe for use in this population.
      CLINICAL IMPLICATIONS: The use of TTDN may also help patients with other forms of ARDS hasten their liberation from MV.
      DISCLOSURES: No relevant relationships by Ali Ataya, source=Web Response
      No relevant relationships by Majd Khasawneh, source=Web Response
      No relevant relationships by Erin Silverman, source=Web Response
      no disclosure on file for Meghan Tornatore;
      no disclosure on file for Cesar Trillo-Alvarez;