Is the venoarterial carbondioxide gradient and lactate predictor of inadequate tissue perfusion during cardiopulmonary bypass?

Abstract

Bu çalışmada kardiopulmoner baypas (KPB) sırasında venoarteriyel karbondioksit farkı (Dv-a PCO2) ve laktat arasındaki muhtemel ilişkisi araştırıldı. Ça lış mapla nı:Hastanemiz etik kurulu onayı ve hasta onamları alınan elektif izole koroner arter baypas greft (KABG) cerrahisi yapılacak 60 ardışık hasta (35 erkek, 53 kadın; ort. yaş 64 yıl; dağılım 38-78 yıl) çalışmaya alındı. Tüm hastalar aynı anestezi ve cerrahi ekip tarafından izlendi. Kardiopulmoner baypas süresince doku perfüzyonun yeterliliği venoarteriyel parsiyel karbondioksit farkı, laktat düzeyi, arteriyel ve venöz kan gazı ölçümü, idrar çıkış hızı ve hemodinamik parametrelerin analizi ile değerlendirildi. Ölçümler kardiopulmoner baypas öncesi (T1), KPB başlangıcında 36 ºC'de (T2), hipotermide 32 ºC'de (T3) ve yeniden ısınmanın sonunda 37 ºC'de (T4) olmak üzere dört periyotta yapıldı. Doku perfüzyon parametreleri arasındaki ilişki, Pearson korelasyon analizi ile değerlendirildi. Bul gu lar: Kardiopulmoner baypasın T2 ile T4 periyotları arasında doku perfüzyon parametrelerinden Dv-aPCO2 ile arteriyel laktat düzeyi (r= 0.55, p= 0.042) ve Dv-aPCO2 ile venöz laktat (r=0.54, p=0.046) arasında anlamlı ilişki vardı. T3-T4 periyotları arasında da Dv-aPCO2 ile arteriyel base excess (BE) (r=-064, p= 0.013,), Dv-aPCO2 ile arteriyel HCO3 (r=-0.54, p=0.048) arasında anlamlı ilişki vardı. So nuç: Çalışma bulgularımız, hipotermi döneminde, karbondioksit çözünürlüğündeki değişikliğe bağlı olarak, KBP sırasında venoarteriyel karbondioksit farkındaki (Dv-aPCO2) artışın yetersiz kan akımı ile ters orantılı olmadığını ve hipotermi periyodu dışındaki dönemlerde, Dv-aPCO2 ile doku perfüzyon parametreleri arasında anlamlı bir ilişkinin olduğunu göstermiştir. Anah tar söz cük ler: Kardiyopulmoner baypas; doku perfüzyonu; venoarteriyel karbondioksit farkı. Background:In this study, we aimed to investigate the possible relationship between the venoarterial gradient of carbon dioxide (Dv-a PCO2) and lactate during cardiopulmonary bypass (CPB). Methods: Sixty consecutive patients (35 males, 53 females; mean age 64 years; range 38 to 78 years) who were scheduled for elective isolated coronary artery bypass graft (CABG) surgery were included in the study after obtaining their informed consent and the approval of the ethics committee of the hospital. All patients were followed up by the same surgical and anesthesia team. The adequacy of tissue perfusion during CPB was evaluated by the venoarterial partial carbon dioxide gradient, lactate level, measurement of arterial and venous blood gas, urinary flow rate, and hemodynamic parameters. The measurements were performed in four periods: before CPB (T1), at the beginning of CPB (T2) at 36 ºC and 32 ºC of hypothermia (T3) and at the end of rewarming (T4) at 37 ºC. The relationship between tissue perfusion parameters was assessed by Pearson's correlation analysis. Results:There was a significant correlation between Dv-aPCO2 and the venous lactate level (r= 0.54, p= 0.046) as well as between Dv-aPCO2 and the arterial lactate level (r= 0.55, ...

Evaluation of Cerebral Oxygenation and Tissue Perfusion in Patients Ongoing Coronary Artery Surgery with Cardiopulmonary By-pass

“…In a study of Toraman et al performed on 60 patients who underwent coronary artery bypass graft surgery; in the hypothermia period, due to the change in carbon dioxide solubility, the increase in ∆pCO 2 during CPB was not inversely proportional to inadequate blood flow and found a significant relationship between ∆pCO 2 and tissue perfusion parameters in periods other than hypothermia period. 15 Another factor affecting pCO 2 is the solubility of CO2. The solubility of CO 2 is 20 times the solubility of oxygen.…”

A comparison between the measurements of arterial lactate and mixed venous oxygen saturation for the evaluation of tissue perfusion after coronary artery bypass grafting

“…[6] However, in case of improved regional perfusion, the level of blood lactate also increases. [3] For the timely diagnosis of poor tissue perfusion, all of the indirect tissue perfusion variables should be closely monitored and evaluated, as they work in conjunction with each other. [3] Routine postoperative evaluation of tissue perfusion presents a significant challenge following open cardiac surgery in patients in whom cardiac pressure-volume relationship has been worsened and, thus, become difficult to assess due to several causes such as impaired left ventricular function, presence of degenerative Table 3.…”

“…Despite the general acceptance of this fact, major postoperative end-organ complications potentially secondary to undetected regional ischemia during bypass. [3] During CPB practice, changes in the re-distribution of blood flow along with any associated negative outcomes has led clinicians to prefer to work with the highest blood flow, MAP and hematocrit values during CPB. In addition, with hypothermia, the total body O 2 consumption (VO 2 ) decreases more than the O 2 supply and an increase in the SvO 2 is observed, particularly in the hypothermic period of CPB.…”

“…This situation decreases the reliability of SvO 2 . [3] On the other hand, macro-circulation may remain normal in some patients with impaired microcirculation and intracellular hypoperfusion, often deceptive clinicians. [2,[10][11][12][13][14] Likewise, impaired microcirculation in the early postoperative period due to a variety of causes may restrict the passage of intracellular lactate to blood, giving a rise to normal blood lactate measurements, despite significant intracellular hypoperfusion.…”

“…[2] Another recent method of tissue perfusion analysis is monitoring of mixed venous oxygen saturation (S mv O 2 ). [3] However, the need for pulmonary artery catheter insertion represents a major drawback for its routine use due to both procedure-related complications and its high cost. [2] In this study, we aimed to investigate the possible correlation between the blood lactate levels and S mv O 2 measurement after coronary artery bypass grafting (CABG).…”