Prolonged prone positioning under VV-ECMO is safe and improves oxygenation and respiratory compliance

Abstract

BackgroundData are sparse regarding the effects of prolonged prone positioning (PP) during VV-ECMO. Previous studies, using short sessions (<12 h), failed to find any effects on respiratory system compliance. In the present analysis, the effects of prolonged PP sessions (24 h) were retrospectively studied with regard to safety data, oxygenation and respiratory system compliance.MethodsRetrospective review of 17 consecutive patients who required both VV-ECMO and prone positioning. PP under VV-ECMO was considered when the patient presented at least one unsuccessful ECMO weaning attempt after day 7 or refractory hypoxemia combined or not with persistent high plateau pressure. PP sessions had a duration of 24 h with fixed ECMO and respiratory settings. PP was not performed in patients under vasopressor treatment and in cases of recent open chest cardiac surgery.ResultsDespite optimized protective mechanical ventilation and other adjuvant treatment (i.e. PP, inhaled nitric oxide, recruitment maneuvers), 44 patients received VV-ECMO during the study period for refractory acute respiratory distress syndrome. Global survival rate was 66 %. Among the latter, 17 patients underwent PP during VV-ECMO for a total of 27 sessions. After 24 h in prone position, PaO2/FiO2 ratio significantly increased from 111 (84–128) to 173 (120–203) mmHg (p < 0.0001) while respiratory system compliance increased from 18 (12–36) to 32 (15–36) ml/cmH2O (p < 0.0001). Twenty-four hours after the return to supine position, tidal volume was increased from 3.0 (2.2–4.0) to 3.7 (2.8–5.0) ml/kg (p < 0.005). PaO2/FiO2 ratio increased by over 20 % in 14/14 sessions for late sessions (≥7 days) and in 7/13 sessions for early sessions (<7 days) (p = 0.01). Quantitative CT scan revealed a high percentage of non-aerated or poorly-aerated lung parenchyma [52 % (41–62)] in all patients. No correlation was found between CT scan data and respiratory parameter changes. Hemodynamics did not vary and side effects were rare (one membrane thrombosis and one drop in ECMO blood flow).ConclusionWhen used in combination with VV-ECMO, 24 h of prone positioning improves both oxygenation and respiratory system compliance. Moreover, our study confirms the absence of serious adverse events.Electronic supplementary materialThe online version of this article (doi:10.1186/s13613-015-0078-4) contains supplementary material, which is available to authorized users.

Prone positioning monitored by electrical impedance tomography in patients with severe acute respiratory distress syndrome on veno-venous ECMO

“…Notably, EIT-identified optimal PEEP before PP did not differ significantly between PCG+ and PCG− (P = 0.09). It was significantly reduced after PP in all patients, shifting from 14.8 (12)(13)(14)(15)(16)(17) to 11.7 (9-14) cmH 2 O for PCG+ , while PCG−, optimal PEEP declined from 12 (8-15.5) to 9 (6.5-11.5) cmH 2 O (Fig. 5).…”

“…Although the use of PP combined with ECMO is still controversial [12], few studies have suggested that it could improve oxygenation and static compliance [13,14], thereby preventing subsequent VILI, when associated with "ultra-protective" ventilation. To date, PP physiological effects on regional ventilation and the optimal positive end-expiratory pressure (PEEP) level in this specific population with very low VT and altered static compliance are unknown.…”

Mechanical Ventilation during Extracorporeal Membrane Oxygenation in Patients with Acute Severe Respiratory Failure

“…In 17 subjects undergoing VV-ECMO who also failed at least one weaning attempt, prolonged prone positioning (24 hours) was performed [65]. Respiratory system compliance increased from 18 (12–36) to 32 (15–36) mL/cmH 2 O ( p < 0.0001), and the PaO 2 /FiO 2 ratio increased from 111 (84–128) to 173 (120–203) mmHg ( p < 0.0001).…”

Veno-venous extracorporeal membrane oxygenation: cannulation techniques

“…The other advantage of the DLB cannula is that it avoids additional femoral cannulation. This allows the use of prone positioning that is currently a common practice implemented in VV-ECMO patients to improve lung recruitment and oxygenation (42) and a patient's early mobilization, such as sitting up in bed and even ambulating, while on VV-ECMO support (43). Ambulatory ECMO programs have been developed in an attempt to provide rehabilitation, physical therapy and minimization of sedation prior to lung transplantation to improve both surgical and post-transplant outcomes.…”