Skip to Main Content

Chapter 33: Extracorporeal Life Support

A 35-year-old man with ARDS and severe refractory hypoxia was placed on VV ECLS 1 hour ago. While on conventional mechanical ventilation, his Pao2 was 59 mmHg, with an Sao2 of 70% despite protective ventilation strategy and a 100% Fio2.

The patient weighs 95 kg, his blood pressure is 110/83 mmHg, and his Hgb is 11 g/dL. He now has a right common femoral drainage cannula and an RIJ infusion cannula. The ECLS flow rate is 60 mL/kg/min with a corresponding centrifugal pump speed of 3200 RPM. The inlet (drainage) Sao2 is 80%, and the outlet (return) Sao2 is 84%. The flow rate is increased to 70 mL/kg/min, corresponding to a pump speed of 3500 RPM, with no change in oxygenation. What is the best next step?

A. Increase the flow rate to 80 mL/kg/min.

B. Transfuse 1 unit of packed red blood cells.

C. Obtain TEE to assess the infusion cannula flow pattern.

D. Continue the current ELCS settings.

C. Obtain TEE to assess the infusion cannula flow pattern.

The high-inlet (drainage) Sao2 indicates the presence of recirculation. Increasing the flow to 80 mL/kg/min will increase recirculation and reduce effective flow and hence systemic oxygenation (choice A). Although increasing the Hgb can increase the oxygen content and Do2, the patient’s current Hgb is satisfactory (choice B). Continuing the same ECLS settings will not resolve recirculation (choice D). Recirculation is a phenomenon that occurs in VV ECMO, especially with two-site cannulation in which the returning jet is close to the inlet (drainage) cannula. Thus, obtaining TEE to assess the infusion cannula flow pattern (choice C) will confirm the diagnosis and allows cannula(s) repositioning. The use of a double-lumen cannula can reduce the risk of recirculation.

You are called to evaluate a 34-year-old woman for ECLS initiation. She was admitted to the ICU 7 days ago after a high-speed motor vehicle accident. She was intubated in the field for a Glasgow Coma Scale score of 4. The computed tomography (CT) scan of the head showed frontal lobe edema and subarachnoid hemorrhage. She was diagnosed with aspiration pneumonia on day 2 and was started on broad-spectrum antibiotics. Over the course of the next 5 days, she had persistent and worsening hypoxia despite multiple ventilator adjustments, paralysis, and prone positioning. She is receiving 8 μg/kg/min of norepinephrine and broad-spectrum antibiotics and has been off sedation and paralytic medications for multiple hours. Her complete blood count, basic metabolic profile, and liver function tests are unremarkable except for a white blood cell count of 18 × 103 K/µL. On physical ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.