**5. Complications**

*Advances in Extracorporeal Membrane Oxygenation - Volume 3*

double lumen catheter with successful survival results.

23-year old

femoral artery

42-year old

No complications reported

complications reported

PaO2 289 mmHg (FiO2 100%)

from hospital without any impairment

neuromyopathy

67-year old

*IMV, invasive mechanical ventilation; NIV, noninvasive mechanical ventilation.*

PaO2 50 mmHg (FiO2 100%)

Extubation 2 days after ECLA No complications reported

Gas exchange with IMV before ECCO2R: pH 7.02, paCO2 100 mmHg,

Case 1: 74-year old. Gas exchange with IMV before ECCO2R: pH 6.87, paCO2 147 mmHg. Extubation after 48 h of ECLA. Complications: Coagulation of membrane that needed changing. Bleeding through

Case 2: 52-year old. Gas exchange with IMV before ECCO2R: pH 7.2,

No gas exchange before IMV reported. Patient successfully extubated

Case 1: 48-year old. Gas exchange with IMV before ECCO2R: pH 6.94, paCO2 147 mmHg, PaO2 416 mmHg (FiO2 100%). Successfully extubated while on ECCO2R and discharged from ICU. No

Case 2: 59-year old. Gas exchange with IMV before ECCO2R: pH 7.12, paCO2 78 mmHg, PaO2 112 mmHg (FiO2 100%). ECCO2R duration: 9 days. Ventilator support discontinued on day 28 due to critical illness

Gas exchange before ECCO2R (on NIV): pH 7.24, paCO2 61 mmHg,

Thirty-four hours after initiating ECCO2R, the patient was weaned entirely from NIV, and the cannula could be removed without any complication. On day 4, the patient was discharged from the ICU without the need for supplemental oxygen and 6 days later, discharged

Extubated on intensive care day 11. No complications reported

and transferred from the ICU on day 14 of admission

Weaning achieved after 20 h of ECLA was commenced

paCO2 130 mmHg. ECCO2R duration: 5 days

**Study ECCO2R technique Major findings**

Extracorporeal lung assist (ECLA); 22-Fr drainage and 18-Fr return femorofemoral cannula with a median blood flow rate of

Femoral AV pumpless extracorporeal lung assist

Femoral AV pumpless extracorporeal lung assist

15-Fr arterial cannula and 17-Fr venous cannula with a mean extracorporeal blood flow of >1.5 L/min

Dual-lumen catheter 20–23 Fr bicaval, inserted into the right internal jugular vein with blood flow of 1.3–1.8 L/min

Awake dual-lumen catheter 22 Fr bicaval, inserted into the right internal jugular vein with blood flow of 0.6–1.5 L/min

*Case series of ECCO2R for near-fatal asthma.*

15-Fr arterial cannula and 17-Fr venous cannula with a mean extracorporeal blood flow of 1.5 L/min

1.7–2 L/min

(PECLA)

(PECLA)

Sakai et al. [53]

Elliot et al. [52]

Jung et al. [54]

Brenner et al. [50]

Schneider et al. [51]

7.17 ± 0.16, PaCO2 119.7 ± 58 mmHg, and PaO2/FiO2 244 ± 180 despite mechanical ventilation. Complications were described in 19 of 24 patients (79.2%) with a remarkable number of hemodynamic, hemorrhagic, and mechanical complications [49]. These data show that in patients treated with ECMO for status asthmaticus, hypercapnia, rather than hypoxemia, was the central exchange derangement, suggesting that a less invasive technique like ECCO2R will be suitable, with fewer complications. Although most of the clinical applications of ECCO2R for the treatment of obstructive lung diseases have been reported in patients with COPD, several cases describe ECCO2R in patients with near-fatal asthma [50–54] (**Table 4**). The first cases reported were by using a pumpless extracorporeal life assist (pECLA) device. Although no complications were described in these case series, a possible major complication may arise as a consequence of the arterial cannulation, such as lower limb ischemia [53]. Brenner et al. reported two cases using a venous

**102**

**Table 4.**

Although ECCO2R seems to be effective in improving or mitigating hypercapnic acidosis and possibly in reducing the rate of endotracheal intubation, its use is associated with a range of vascular, hematological, and other complications.

Arterial cannulation is associated with higher risk than venous catheterization, with specific complications including distal limb ischemia, compartment syndrome of the lower limb requiring fasciotomy, or limb amputation as devastating consequences [16].

The occurrence of bleeding events is the most frequent complications of ECCO2R. The low flow renders systemic anticoagulation mandatory, increasing the risk of significant bleeding including cerebral, gastrointestinal, and nasopharyngeal bleeds. In the studies of ECCO2R to date, the rate of clinically significant hemorrhagic complications ranges between 2 and 50% [44].

Thrombocytopenia and heparin-induced thrombocytopenia are also commonly observed.

Conversely, thrombus formation is higher at lower blood flow rates because of increased exposure time to the membrane lung and circuit. Clots may detach and enter the patient's bloodstream, plugging the membrane or obstructing the cannula if anticoagulation is not achieved.
