ΔvapCO2 / Cav02 Ratio as a Prognostic Marker and Predictor of Complications After Cardiac Surgery

Using the ΔvapCO2 / Cav02 Ratio as a Prognostic Marker and Predictor of Complications After Cardiac Surgery

This study evaluates the usefulness of the ΔvapCO2 / Cav02 ratio to predict complications after elective cardiac surgery, comparing it with others markers such as lactate, arteriovenous CO2 difference (ΔvapCO2) and would try to developed a new predictive score for postoperative complications.

Study Overview

• Status: Unknown
• Conditions: Postoperative Complications; Shock; Cardiac Surgery; Disorder of Blood Gas

Detailed Description

Cardiac surgery is widely used to solve valvular or coronary problems and often requires the use of cardiopulmonary bypass or extracorporeal circulation (EC).

The EC itself produces a series of changes in the macro- and microcirculation hemodynamic and physiological consequences in the hours following surgery that can be difficult to analyze.

During postoperatively management, different monitoring methods are used to optimize different hemodynamic and analytical variables.

Sometimes, monitored variables are corrected but the patient still develops complications such as kidney failure, prolonged mechanical ventilation or even death. In fact, it is not well known either if it is sufficient to correct the variables called "macrodynamics " such as mean arterial pressure (MAP) , stroke volume (SV), pulmonary artery occlusion pressure (PCWP) and cardiac index (CI) or if it is necessary to correct other "micro-dynamics" variables like lactate, to achieve a certain central venous oxygen saturation (ScvO2) or arteriovenous CO2 difference(ΔvapCO2).

In tissue hypoxia, damping of excess protons by bicarbonate increase CO2 production; therefore the relationship between CO2 production and oxygen consumption (VCO2/VO2 ratio or respiratory quotient) increases. This ratio can be simplified relating ΔvapCO2 and O2 content arteriovenous difference (ΔvapCO2 / Cav02 ratio). In shock, anaerobic metabolism is one of the primary energy source. In this situation, ΔvapCO2 / Cav02 is > 1.

The evolution of the ΔvapCO2 / Cav02 ratio and its association with prognosis have nnot been studied yet after cardiac surgery.

The study's objectives are:

• to describe ΔvapCO2 / Cav02 ratios kinetics compared to lactate and other biochemical markers (troponin I, BE) in the first 12 hours after cardiac surgery.
• define if ΔvapCO2 / Cav02 ratio> 1 after 6 hours of adequate postsurgical resuscitation correlates with worse prognosis in patients after cardiac surgery.
• develop a new prognostic score for postoperative complication that includes ΔvapCO2 / Cav02 ratio.

Blood gases and drawn from a central venous and arterial lines. pCO2, O2 content, lactate are analyzed at 0, 2, 6 and 12 hs. Macrodynamic variables are also collected, as well as, the need of extracorporeal support techniques.

Patients would be followed for the next 28 days after surgery.

• Study Type: Observational
• Enrollment (Anticipated): 150

Contacts and Locations

Study Locations

• Spain
  • Madrid, Spain, 28040
    • Recruiting
    • Hospital Clinico San Carlos
    • Contact: Tomás F Fariña González, MD; Email: tomas_scout@hotmail.com
    • Principal Investigator: Tomás F Fariña González, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

Patients undergoing elective cardiac surgery in an university hospital that would be followed during the postoperative time in the Cardiovascular Intensive Care Unit.

Description

Inclusion Criteria:

• 18 years old or more
• given informed consent
• elective cardiac surgery
• tip of a central venous catheter correctly positioned (superior vena cava or right atria)
• arterial catheter correctly positioned

Exclusion criteria:

• pregnancy

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
all cause mortality		within the first 28 days after surgery
all cause intra-ICU mortality		within the first 28 days after surgery
Ventilator days	Time that is required to extubate the patient	within the first 28 days after surgery
ICU stay length		within the first 28 days after surgery
Hospital stay length		within the first 28 days after surgery
Acute kidney failure	According RIFLE classification	within the first 28 days after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Vasoactive requirements after 12 hs	Noradrenaline or dobutamine requirement after 12 hs (yes/no)	First 12 hs postoperative
Volume infused over 12 hs (ml)		First 12 hs postoperative
Intraaortic counterpulsation balloon	Need of Intraaortic baloon counterpulsation (yes/no)	First 12 hs postoperative
Ventricular mechanical assistance	Need of ventricular mechanical assistance (yes/no)	First 12 hs postoperative
Renal replacement therapies	Need of renal replacement therapies (yes/no)	within the first 28 days after surgery

Collaborators and Investigators

• Sponsor: Hospital San Carlos, Madrid

Publications and helpful links

General Publications

• Du W, Long Y, Wang XT, Liu DW. The Use of the Ratio between the Veno-arterial Carbon Dioxide Difference and the Arterial-venous Oxygen Difference to Guide Resuscitation in Cardiac Surgery Patients with Hyperlactatemia and Normal Central Venous Oxygen Saturation. Chin Med J (Engl). 2015 May 20;128(10):1306-13. doi: 10.4103/0366-6999.156770.
• Hu BY, Laine GA, Wang S, Solis RT. Combined central venous oxygen saturation and lactate as markers of occult hypoperfusion and outcome following cardiac surgery. J Cardiothorac Vasc Anesth. 2012 Feb;26(1):52-7. doi: 10.1053/j.jvca.2011.07.021. Epub 2011 Sep 15.
• Habicher M, von Heymann C, Spies CD, Wernecke KD, Sander M. Central Venous-Arterial pCO2 Difference Identifies Microcirculatory Hypoperfusion in Cardiac Surgical Patients With Normal Central Venous Oxygen Saturation: A Retrospective Analysis. J Cardiothorac Vasc Anesth. 2015;29(3):646-55. doi: 10.1053/j.jvca.2014.09.006. Epub 2015 Jan 6.
• Robin E, Futier E, Pires O, Fleyfel M, Tavernier B, Lebuffe G, Vallet B. Central venous-to-arterial carbon dioxide difference as a prognostic tool in high-risk surgical patients. Crit Care. 2015 May 13;19(1):227. doi: 10.1186/s13054-015-0917-6.
• Mekontso-Dessap A, Castelain V, Anguel N, Bahloul M, Schauvliege F, Richard C, Teboul JL. Combination of venoarterial PCO2 difference with arteriovenous O2 content difference to detect anaerobic metabolism in patients. Intensive Care Med. 2002 Mar;28(3):272-7. doi: 10.1007/s00134-002-1215-8. Epub 2002 Feb 8.
• Ospina-Tascon GA, Umana M, Bermudez W, Bautista-Rincon DF, Hernandez G, Bruhn A, Granados M, Salazar B, Arango-Davila C, De Backer D. Combination of arterial lactate levels and venous-arterial CO2 to arterial-venous O 2 content difference ratio as markers of resuscitation in patients with septic shock. Intensive Care Med. 2015 May;41(5):796-805. doi: 10.1007/s00134-015-3720-6. Epub 2015 Mar 20.
• Balzer F, Sander M, Simon M, Spies C, Habicher M, Treskatsch S, Mezger V, Schirmer U, Heringlake M, Wernecke KD, Grubitzsch H, von Heymann C. High central venous saturation after cardiac surgery is associated with increased organ failure and long-term mortality: an observational cross-sectional study. Crit Care. 2015 Apr 16;19(1):168. doi: 10.1186/s13054-015-0889-6.

Study record dates

Study Major Dates

• Study Start: October 1, 2016
• Primary Completion (Anticipated): September 1, 2017
• Study Completion (Anticipated): October 1, 2017

Study Registration Dates

• First Submitted: August 9, 2016
• First Submitted That Met QC Criteria: August 18, 2016
• First Posted (Estimate): August 23, 2016

Study Record Updates

• Last Update Posted (Estimate): October 26, 2016
• Last Update Submitted That Met QC Criteria: October 25, 2016
• Last Verified: October 1, 2016

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Postoperative Complications
• Other Study ID Numbers: C.P. - C.I. 16/359-E

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No