Monitoring the tissue perfusion during hemorrhagic shock and resuscitation: tissue-to-arterial carbon dioxide partial pressure gradient in a pig model

Abstract Background: Transcutaneous CO2 (tcPCO2) and arterial CO2 (artPCO2) decoupling occurs during shock states. Our study aimed to test the hypothesis that the gradient between tcPCO2 and artPCO2 (tc-artPCO2) can detect inadequate tissue perfusion during hemorrhagic shock and resuscitation. Methods: This prospective animal study was performed by a qualified and experienced research team using female pigs (LWD, weighing 29–34 kg) at university-based experimental laboratory. Progressive massive hemorrhagic shock was induced in mechanically-ventilated pigs by stepwise blood withdrawal. Next, all the animals were then resuscitated by transfusing the stored blood in stages. A transcutaneous monitor was attached to the animals’ ear to measure the tcPCO2 and transcutaneous oxygen pressure (tcPO2). The pulmonary artery catheter (PAC) and pulse index continuous cardiac output (PiCCO) were used to monitor several hemodynamic parameters. Results: Hemorrhage and blood transfusion precisely impacted hemodynamic and laboratory data, such as cardiac output (CO), stroke volume, mean arterial pressure, heart rate, pulmonary artery wedge pressure, global end-diastolic volume, hemoglobin, and arterial lactate. The tc-artPCO2 level markedly increased as CO decreased. In the analyses of the 42 paired measurements, there were significant correlations of tc-artPCO2 with systemic oxygen delivery (DO2) and CO (DO2: r = -0.83, CO by PAC: r = -0.79; CO by PiCCO: r = -0.74; all P < 0.0001) levels. The critical level of oxygen delivery (DO2crit) was 11.72 mL/kg/min according to tcPO2 (at a threshold of 30 mmHg). The receiver operating characteristic curve analyses revealed that the area under the curves (AUCs) that predicted DO2crit for tc-artPCO2, shock index (SI), and lactate were 0.94 (95% confidence interval, 0.87-1.00); 0.78 (0.63-0.93); and 0.65 (0.47-0.82), respectively. The AUC for tc-artPCO2 was greater in predicting DO2crit than that for SI.Conclusions: tc-artPCO2 was strongly correlated with DO2 during hemorrhagic shock and resuscitation. This less-invasive tc-artPCO2 monitoring can sensitively detect inadequate systemic O2 supply during hemorrhagic shock. Further evaluations are required in different forms of shock in other large animal models and in humans to assess its usefulness, safety, and ability to predict outcomes in critical illnesses.

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Monitoring the Tissue Perfusion During Hemorrhagic Shock and Resuscitation: Tissue-to-arterial Carbon Dioxide Partial Pressure Gradient in a Pig Model

10.21203/rs.3.rs-684619/v1 ◽

2021 ◽

Author(s):

Yusuke Endo ◽

Taku Hirokawa ◽

Taku Miyasho ◽

Ryosuke Takegawa ◽

Koichiro Shinozaki ◽

...

Keyword(s):

Cardiac Output ◽

Pulmonary Artery ◽

Hemorrhagic Shock ◽

Oxygen Delivery ◽

Laboratory Data ◽

Tissue Perfusion ◽

Carbon Dioxide Partial Pressure ◽

Large Animal ◽

Transcutaneous Oxygen ◽

Large Animal Models

Abstract Background: Transcutaneous CO2 (tcPCO2) and arterial CO2 (artPCO2) decoupling occurs during shock states. Our study aimed to test the hypothesis that the gradient between tcPCO2 and artPCO2 (tc-artPCO2) can detect inadequate tissue perfusion during hemorrhagic shock and resuscitation. Methods: This prospective animal study was performed by a qualified and experienced research team using female pigs (LWD, weighing 29–34 kg) at university-based experimental laboratory. Progressive massive hemorrhagic shock was induced in mechanically-ventilated pigs by stepwise blood withdrawal. Next, all the animals were then resuscitated by transfusing the stored blood in stages. A transcutaneous monitor was attached to the animals’ ear to measure the tcPCO2 and transcutaneous oxygen pressure (tcPO2). The pulmonary artery catheter (PAC) and pulse index continuous cardiac output (PiCCO) were used to monitor several hemodynamic parameters. Results: Hemorrhage and blood transfusion precisely impacted hemodynamic and laboratory data, such as cardiac output (CO), stroke volume, mean arterial pressure, heart rate, pulmonary artery wedge pressure, global end-diastolic volume, hemoglobin, and arterial lactate. The tc-artPCO2 level markedly increased as CO decreased. In the analyses of the 42 paired measurements, there were significant correlations of tc-artPCO2 with systemic oxygen delivery (DO2) and CO (DO2: r = -0.83, CO by PAC: r = -0.79; CO by PiCCO: r = -0.74; all P < 0.0001) levels. The critical level of oxygen delivery (DO2crit) was 11.72 mL/kg/min according to tcPO2 (at a threshold of 30 mmHg). The receiver operating characteristic curve analyses revealed that the area under the curves (AUCs) that predicted DO2crit for tc-artPCO2, shock index (SI), and lactate were 0.94 (95% confidence interval, 0.87-1.00); 0.78 (0.63-0.93); and 0.65 (0.47-0.82), respectively. The AUC for tc-artPCO2 was greater in predicting DO2crit than that for SI.Conclusions: tc-artPCO2 was strongly correlated with DO2 during hemorrhagic shock and resuscitation. This less-invasive tc-artPCO2 monitoring can sensitively detect inadequate systemic O2 supply during hemorrhagic shock. Further evaluations are required in different forms of shock in other large animal models and in humans to assess its usefulness, safety, and ability to predict outcomes in critical illnesses.

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Abstract 10679: Tissue-to-Arterial Carbon Dioxide Partial Pressure Gradient as a Useful Measure for Monitoring Tissue Perfusion in a Pig Model of Hemorrhagic Shock and Resuscitation

Circulation ◽

10.1161/circ.144.suppl_2.10679 ◽

2021 ◽

Vol 144 (Suppl_2) ◽

Author(s):

Yusuke Endo ◽

Lance B Becker ◽

Ryosuke Takegawa ◽

Santiago J Miyara ◽

Ernesto P Molmenti ◽

...

Keyword(s):

Cardiac Output ◽

Blood Transfusion ◽

Pulmonary Artery ◽

Hemorrhagic Shock ◽

Laboratory Data ◽

Tissue Perfusion ◽

Pig Model ◽

Carbon Dioxide Partial Pressure ◽

End Diastolic Volume ◽

O2 Supply

Introduction: Transcutaneous CO 2 (tcPCO 2 ) and arterial CO 2 (artPCO 2 ) become decoupled during shock. Aim: To test the hypotheses the gradient between tcPCO 2 and artPCO 2 (tc-artPCO 2 ) can be an early, sensitive measure to detect inadequate tissue perfusion in a pig model of hemorrhage shock. Methods: Six female pigs were used. A transcutaneous monitor was attached to the ear for measuring transcutaneous O 2 (tcPO 2 ) and tcPCO 2 . Pulmonary artery catheter and the pulse index continuous cardiac output (PiCCO) were instrumented for monitoring a variety of hemodynamic parameters. To induce massive hemorrhagic shock, blood was withdrawn stepwisely. Then, animals were resuscitated in stages with transfusions of the stored blood. The parameters were measured at the timings of 10, 20, and 30 ml/kg of blood withdrawals and the completions of 10, 20, and 30 ml/kg of blood transfusion . Levels of systemic oxygen delivery (DO 2 ) were also calculated at all measurement points. Results: Hemorrhage and blood transfusion impacted hemodynamic and laboratory data, such as cardiac output (CO), stroke volume, MAP, heart rate, pulmonary artery wedge pressure, global end-diastolic volume, hemoglobin, and arterial lactate. The tc-artPCO 2 markedly increased as CO decreased ( Figure A ). The critical level of DO 2 (DO 2crit ) was defined as 11.72 ml/kg/min according to tcPO 2 (a threshold as 30 mmHg). There was significant correlation between tc-artPCO 2 and DO 2 (r = -0.83, P<.0001). ROC analyses revealed that the AUCs to predict DO 2crit for tc-artPCO 2 , shock index (SI), and lactate were 0.94 (95% CI, 0.87-1.00), 0.78 (0.63-0.93), and 0.65 (0.47-0.82), respectively. The AUC for tc-artPCO 2 was greater with respect to the prediction of DO 2crit than for SI (P<.05) ( Figure B ). Conclusions: The tc-artPCO 2 strongly correlated with CO and DO 2 during hemorrhage shock and resuscitation. The less-invasive tc-artPCO 2 monitoring can sensitively detect systemic inadequate O2 supply in hemorrhagic shock.

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