Characteristics of sublingual microcirculatory changes during the early postoperative period following cardiopulmonary bypass-assisted cardiac surgery-a prospective cohort study

Xiaofeng Li; Tong Tan; Hongxiang Wu; Chongjian Zhang; Dandong Luo; Weizhong Zhu; Boyu Li; Jian Zhuang

doi:10.21037/jtd-22-1159

Characteristics of sublingual microcirculatory changes during the early postoperative period following cardiopulmonary bypass-assisted cardiac surgery-a prospective cohort study

J Thorac Dis. 2022 Oct;14(10):3992-4002. doi: 10.21037/jtd-22-1159.

Authors

Xiaofeng Li^#¹, Tong Tan^#¹, Hongxiang Wu^#¹, Chongjian Zhang¹, Dandong Luo¹, Weizhong Zhu¹, Boyu Li², Jian Zhuang³

Affiliations

¹ Department of Cardiovascular Surgery, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangdong Provincial Key Laboratory of South China Structural Heart Disease, Guangzhou, China.
² Department of Center for Private Medical Service & Healthcare, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
³ Department of Cardiovascular Surgery, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangdong Cardiovascular Institute, Laboratory of Artificial Intelligence and 3D Technologies for Cardiovascular Diseases, Guangdong Provincial Key Laboratory of South China Structural Heart Disease, Guangzhou, China.

^# Contributed equally.

Abstract

Background: Persistent microcirculatory dysfunction associated with increased morbidity and mortality. Interventions in the early resuscitation can be tailored to the changes of microcirculation and patient's need. However, there is usually an uncoupling of macrocirculatory and microcirculatory hemodynamics during resuscitation. Current research on the patterns of microcirculatory changes and recovery after cardiopulmonary bypass (CPB)-assisted cardiac surgery is limited. This study aimed to analyze changes in the microcirculatory parameters after CPB and their correlation with macrocirculation and to explore the characteristics of microcirculatory changes following CPB-assisted cardiac surgery.

Methods: Between December 2018 and January 2019, 24 adult patients with indwelling pulmonary artery catheters after elective cardiac surgery using CPB were enrolled in this study. Both microcirculatory and macrocirculatory parameters were collected at 0, 6, 16, and 24 hours after admission to the intensive care unit (ICU). Video images of sublingual microcirculation were analyzed to obtain the microcirculatory parameters, including total vascular density (TVD), perfused small vessel density (PSVD), the proportion of perfused small vessels (PPV), microvascular flow index (MFI), and flow heterogeneity index (HI). The characteristics of microcirculatory parameter change following cardiac surgery and the correlation between microcirculatory parameters and macroscopic hemodynamic indicators, oxygen metabolic indicators, and carbon dioxide partial pressure difference (PCO₂gap) were analyzed.

Results: There were significant differences in the changes of TVD (P=0.012) and PSVD (P=0.005) during the first 24 hours postoperatively in patients who underwent CPB-assisted cardiac surgery. The microcirculatory density parameters (TVD: r=-0.5059, P=0.0456; PVD: r=-0.5499, P=0.0273) were correlated with oxygen delivery index (DO₂I) at 24 hours after surgery. The microcirculatory flow parameters (PPV: r=0.4370, P=0.0327; MFI: r=0.6496, P=0.0006; and HI: r=-0.5350, P=0.0071) had a strong correlation with PCO₂gap at 0 hour after surgery.

Conclusions: TVD and PSVD might be two most sensitive indicators affected by CPB-assisted cardiac surgery. There was no consistency between microcirculation and macrocirculation until 24 hours following cardiac surgery, meaning the improvement of systemic hemodynamic indicators does not guarantee correspondently improvement in microcirculation. Early controlled oxygen supply after CPB-assisted cardiac surgery may be conducive to the resuscitation of patients to a certain extent.

Keywords: Cardiopulmonary bypass (CPB); cardiac surgery; microcirculation.