Extracorporeal carbon dioxide removal as a bridge to lung transplantation in life-threatening hypercapnia

Introduction

The introduction of the lung allocation score has resulted in a growing number of patients who are considered for lung transplantation (LTX) while being acutely decompensated. In the sickest of these patients, mechanical ventilation (MV) alone may not be sufficient to establish adequate gas exchange. Thus, different modes of extracorporeal life support have come to the focus of interest in this setting.

Methods

A retrospective analysis of 17 patients (male/female ratio: 6/11; median age: 35 (range 16 to 63)) who underwent arteriovenous or venovenous interventional lung assist (iLA; Novalung, Germany) support as bridging to primary LTX (n = 11) or re-LTX (n = 6) between 2005 and 2013.

Results

The underlying diagnosis was bronchiolitis obliterans syndrome III in re-LTX patients (n = 6), cystic fibrosis (n = 5), idiopathic pulmonary fibrosis (n = 2), emphysema (n = 1), adult respiratory distress syndrome (n = 1), hemosiderosis (n = 1), and chronic obstructive lung disease (n = 1), respectively. The type of iLA was arteriovenous in 10 and venovenous (iLA active) in seven patients. The median bridging time was 14 (1 to 58) days. The type of transplantation was bilateral LTX (n = 6), size-reduced bilateral LTX (n = 5), lobar bilateral LTX (n = 4), and right single LTX with contralateral pneumonectomy (n = 1), respectively. Hypercapnia was effectively corrected in all patients within the first 12 hours of iLA therapy: PaCO₂ levels declined from 145 (70 to 198) to 60 (36 to 99) mmHg, P < 0.0001. iLA was initiated during non-invasive ventilation in three patients, of whom one was intubated prior to LTX. All other patients (n = 14) were placed on iLA while on invasive MV. Of those, three patients were extubated and remained on iLA until LTX, one patient was weaned from iLA and remained on MV until LTX, and one patient was weaned from iLA and MV prior to LTX. Five patients were switched to extracorporeal membrane oxygenation (venovenous n = 2, venoarterial n = 3) after 5 (1 to 30) days on iLA support. One patient died prior to LTX due to septic multiorgan failure (SMOF). All others (n = 16; 94%) were successfully transplanted. Of these, two patients died in the ICU due to SMOF. The remaining 14 patients (82%) survived to hospital discharge and were alive at a median follow-up of 20 (1 to 63) months.

Conclusion

In patients with life-threatening hypercapnia, bridging to LTX with iLA is feasible, and results in favorable short-term and longterm outcome.