Table 4.
Main laboratory tests used for the management of patients on extracorporeal membrane oxygenation
| Exams | When to collect | Therapeutic target | Considerations |
|---|---|---|---|
| ACT | Immediately after cannulation of ECMO | Initially, between 180 and 220 seconds. After collection of test, anticoagulation adjustment should be guided by aPTT or anti-Xa activity. | Easy to perform, can be performed at the bedside Result available quickly It allows the initial adjustment of heparin infusion |
| aPTT | Daily. It can be collected more than once per day, especially in cases of adjustment of heparin infusion. | Keep between 40 and 55 seconds | Adequate management of anticoagulation is essential to avoid complications such as system coagulation and intracranial hemorrhage. |
| Anti-Xa activity | Alternative to the aPTT. It can be collected more than once per day, especially in cases of adjustment of heparin infusion. | Keep between 0.2 and 0.3IU/mm | Adequate management of anticoagulation is essential to avoid complications such as system coagulation and intracranial hemorrhage. |
| Platelets | Daily. It can be collected more than once per day, especially in cases of bleeding. | Ideally kept greater than 100,000 cells per mm3 | Platelets are an essential component of hemostasis and in the prevention of hemorrhagic complications. |
| Hemoglobin | Daily. It can be collected more than once per day, especially in cases of bleeding. | Ideally kept greater than 8.0 g/dL | Hemoglobin is a key component of oxygen transport. |
| D-Dimer | Daily. It can be collected more than once per day | Not applicable | Sudden elevation of D-dimer level is strongly indicative of clot formation, predicting failure of the ECMO system. |
| SvcO2 | Daily | Ideally maintained greater than 70%, especially in VA-ECMO. | It allows for the adjustment of VA-ECMO flow. |
| PaCO2 | Daily | Ideally, it was maintained close to 40mmHg, especially in VV-ECMO. | Allows for the adjustment of the fresh gas flow rate Patients with PaCO2 > 50mmHg should be subjected to slow and gradual reduction (not to exceed reduction values greater than 10mmHg per hour). |
ACT - activated coagulation time; ECMO - extracorporeal membrane oxygenation; aPTT: activated partial thromboplastin time; VA-ECMO - venoarterial extracorporeal membrane oxygenation; VV-ECMO - venovenous extracorporeal membrane oxygenation. It is recommended that heparin infusion be initially guided by the activated coagulation time. After the collection of laboratory tests, heparin infusion should ideally be guided by the activated partial thromboplastin time or, alternatively, by anti-Xa activity.