Calculating mixed venous saturation during veno-venous extracorporeal membrane oxygenation

Walker, Joshua L.; Gelfond, Jonathan; Zarzabal, Lee Ann; Darling, Edward
September 2009
Perfusion;Sep2009, Vol. 24 Issue 5, p333
Academic Journal
Introduction: Recirculation (R), the shunting of arterial blood back into to the venous lumen, commonly occurs during veno-venous extracorporeal membrane oxygenation (VV-ECMO) and renders the monitoring of the venous line oxygen saturation no longer reflective of patient mixed venous oxygen saturation (SVO2). Previously, we failed to prove the hypothesis that, once R is known, it is possible to calculate the SVO2 of a patient on VV-ECMO. We hypothesize that we can calculate SVO2 during VV-ECMO if we account for and add an additional correction factor to our model for dissolved oxygen content. Therefore, the purpose of this study is to derive a more accurate model that will allow clinicians to determine SVO2 during VV-ECMO when ultrasound dilution is being used to quantify R. Methods: Using an extracorporeal circuit primed with fresh porcine blood, two stocks of blood were produced; (1) arterial blood (AB), and (2) venous blood (VB). To mimic recirculation, the AB and VB were mixed together in precise ratios using syringes and a stopcock manifold. Six paired stock AB/VB sets were prepared. Two sets were mixed at 20% R increments and 4 sets were mixed at 10% R increments. The partial pressure of oxygen (pO2) and oxygen (O2) saturation of the stock blood and resultant mixed blood was determined. The original model was modified by modeling the residual errors with linear regression. Results: When using the original model, as the partial pressure of arterial oxygen (PaO2) of the stock AB increased, the calculated SVO2 was higher than actual, especially at higher R levels. An iteration of the original model incorporating the PaO2 level (low, medium, high) and R was derived to fit the data. Conclusions: The original model using R and circuit saturations for the calculation of SVO2 in VV-ECMO patients is an oversimplification that fails to consider the influence of the high pO2 of arterial blood during therapy. In the future, further improvements in this model will allow clinicians accurately to calculate SVO2 in conjunction with recirculation measurements.


Related Articles

  • Analysis of Vascular Access in Haemodialysis Patients - Single Center Experience. HEMACHANDAR, R. // Journal of Clinical & Diagnostic Research;Oct2015, Vol. 9 Issue 10, p1 

    Background: Vascular access is the key in successful management of chronic haemodialysis (HD) patients. Though native arteriovenous fistula (AVF) is considered the access of choice, many patients in our country initiate haemodialysis through central venous catheter (CVC). There is paucity of...

  • Aplicaciones de la ecografía perioperatoria y de cuidado crítico. Quintana Puerta, Julián Esteban // Colombian Journal of Anesthesiology / Revista Colombiana de Anes;2014, Vol. 42 Issue 2, p114 

    As an extension to the physical exam, point of care ultrasonography is a tool with multiple applications. Widely used for regional anesthesia, there is not enough diffussion among anesthesiologist of the multiple possibilities that echography gives to them. This article was written to help...

  • 36147 Details Hone Your Diagnostic AV Shunt Coding.  // General Surgery Coding Alert;Nov2012, Vol. 14 Issue 11, pp85 

    In this article the author discusses the Current Procedural Terminology (CPT) guidelines for arteriovenous (AV) shunt. It is stated that the guidelines provides access to radiological evaluation of dialysis which includes fluoroscopy, image documentation and report. It further define the...

  • Preoperative assessment and planning of haemodialysis vascular access. Lomonte, Carlo; Basile, Carlo // Clinical Kidney Journal;Jun2015, Vol. 8 Issue 3, p278 

    Effective haemodialysis (HD) requires a reliable vascular access (VA). Clinical practice guidelines strongly recommend the arteriovenous fistula (AVF) as the preferred VA in HD patients. The creation of an AVF should be promoted in all eligible patients who choose HD, as it improves outcomes and...

  • Ansprüche des Nephrologen an den guten Dialysezugang. Ott, U.; Sperschneider, H. // Der Chirurg;Sep2012, Vol. 83 Issue 9, p775 

    Vascular access is the lifeline of hemodialysis patients. The superiority of autogenous arteriovenous fistulas compared to prostethic arteriovenous grafts or a central venous catheter is well established. Fistulas have a far lower risk of failure and a reduced requirement for revision compared...

  • Placing a primary arteriovenous fistula that works—more or less known aspects, new ideas. Konner, Klaus; Lomonte, Carlo; Basile, Carlo // Nephrology Dialysis Transplantation;Apr2013, Vol. 28 Issue 4, p781 

    Despite the pre-operative availability of well-defined criteria to create a primary arteriovenous fistula (AVF) a high early failure/missing maturation is complained worldwide. Based on new results from basic research using numerical techniques, the authors try to guide attention to a widely...

  • Intraosseous access and adults in the emergency department. Lowther, Ashleigh // Nursing Standard;8/3/2011, Vol. 25 Issue 48, p35 

    This article examines the use of the intraosseous route for obtaining vascular access in adults. It discusses indications for intraosseous access, the techniques and devices used, and contraindications.

  • Influence of Vascular Access Type on Sex and Ethnicity-Related Mortality in Hemodialysis-Dependent Patients. Woo, Karen; Yao, Janis; Selevan, David; Hye, Robert J. // Permanente Journal;Spring2012, Vol. 16 Issue 2, p4 

    Objectives: To determine whether sex- and ethnicity-based mortality differences in patients dependent on hemodialysis (hemodialysis patients) are because of prevalence of vascular access type. Methods: Southern California Permanente Medical Group Renal Database, which contained 5821 chronic...

  • Evaluation of Success Rate of Ultrasound-Guided Venous Cannulation in Patients with Difficult Venous Access. Etezazian, S.; Tavakoli, B.; Hekmatnia, A.; Omidifar, N.; Moradi, M. // Iranian Journal of Radiology;2010, Vol. 7 Issue 2, p61 

    Background/Objective: We evaluated a new ultrasound-guided approach to percutaneous cephalic vein or basilic vein cannulation in patients with difficult intravenous access. Patients and Methods: Patients who required intravenous access and were candidates for surgical approach, or central venous...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics