Clinical trial NCT05679778: PCO2 Gab Marker of Tissue Adequacy of Cardiac Output in Shock State
Official title: PCO2 Gab as a Marker of Tissue Adequacy of Cardiac Output in Sever Shock State, Compared to Other Tissue Perfusion Indicators.
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: Shock
Keywords: Delta PCO2 gap
Echocardiography
Left ventricle outflow tract velocity
Lead sponsor: Assiut University
Sponsor class: OTHER
First posted: 2023-01-11
Enrollment: 137
Sex: ALL
Minimum age (years): 18
Maximum age (years): 90
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: OTHER
Time perspective: CROSS_SECTIONAL
Sampling method: NON_PROBABILITY_SAMPLE
Study population: All critical ill-patients of all age groups, who presented shocked, with good echocardiographic window, with CVC insertion.

Brief summary: 1. To assess validity of of central and pulmonary veno - arterial CO2 gradient to predict fluid responsiveness and to guide fluid management and determine the cut off point to continue or stop resuscitation.
2. comparison between PCO2 gab and left ventricular outflow tract velocity time integral to determine whether to continue or stop resuscitation and whether PCO2 gab is a surrogate of cardiac output or not.

Detailed description: Assessing the adequacy of oxygen delivery with oxygen requirements is one of the key-goal of hemodynamic resuscitation. Clinical examination, lactate and central or mixed venous oxygen saturation (SvO2 an ScvO2 respectively) all have their limitations (Gavelli et al., 2019). The veno- arterial difference in CO2 tension (delta CO2 or PCO2 gap) is not indicator of anaerobic metabolism since it is influenced by the oxygen consumption. By contrast, it reliably indicates whether blood flow to remove is sufficient to carry CO2 from prepheral tissues to the lung in view of its clearance: it, thus, reflects the adequacy of cardiac output with the metabolic condition (valley et al., 2013). The gap is a marker of adequacy of venous blood flow to remove CO2 produced rather than a marker of tissue hypoxia (Vallet et al., 2013).

The gab can be calculated from simultaneous sampling of central venous blood from a central vein catheter and arterial blood.

Determining the delta PCO2 during resuscitation of septic shock Patients might be useful when deciding when to continue resuscitation despite a central venous oxygen saturation\>70% associated with elevated blood lactate levels. because a high blood lactate level is not a discriminatory factor in determining the source of that stress, an increased delta PCO2 (\>6 mmHg) could be used to identify Patients who still remain inadequately resuscitated.

Fluid responsiveness in shocked patients is conventionally defined as an increase of at least 10% to 15% in stroke volume in response to a fluid challenge. Assessment of response to a fluid challenge can be guided with echocardiography. It is achieved by measuring left ventricular outflow tract velocity time integral (LVOT VI) immediately before and after fluid challenge (miller et al; 2016).

Eligibility criteria: Inclusion Criteria:

* all critical ill-patients with acute physiological assessment and chronic health evaluation II score (APACHE II score)≥25 with central line insertion, in the critical care uint of internal medicine department of Assuit university hospital in the period between January 2023 to January 2024.

Exclusion Criteria:

1. Pateints with poor echocardiographic window.
2. Pateints with APACHE II score \< 25.

Primary outcomes:
measure: Improvement of heamodynamic state, need of fluid resuscitation and inotropes.
timeFrame: January 2023 to January 2024
Secondary outcomes:
measure: Duration of hospital stay, time to control various clinical and laboratory abnormalities (BP, PP, RR, lactate, renal chemistry) and development of complications as; pulmonary edema and use of mechanical ventilation.
timeFrame: January 2023 to January 2024
Other outcomes:
Locations:
Study officials:
affiliation: Assiut University
name: Khaled Ali
role: PRINCIPAL_INVESTIGATOR
References:
citation: Gavelli F, Teboul JL, Monnet X. How can CO2-derived indices guide resuscitation in critically ill patients? J Thorac Dis. 2019 Jul;11(Suppl 11):S1528-S1537. doi: 10.21037/jtd.2019.07.10.