Document Type : Original Article
Authors
1 Department of Cardiac Anesthesia, Amrita Institute of Medical Sciences, Amrita School of Medicine, Amrita Vishwa Vidyapeetham, Kochi, India
2 Department of Respiratory Therapy Unit, Amrita Institute of Medical Sciences, Amrita School of Medicine, Amrita Vishwa Vidyapeetham, Kochi, India
3 Department of Anesthesia, Amrita Institute of Medical Sciences, Amrita School of Medicine, Amrita Vishwa Vidyapeetham, Kochi, India
Abstract
Objective: Fluids are administered to optimize hemodynamics during off-pump coronary artery bypass grafting (CABG), which may lead to a positive fluid balance and increased lung water, lung congestion, hypoxemia, prolonged mechanical ventilation, and longer hospital stays. Lung ultrasound can assess extravascular lung water and help titrate diuretics and fluids, thus preventing hypoxemia. The primary objective of this study was to study the correlation between B-line scores measured by lung ultrasound and the PaO2/FiO2 ratio (the ratio of arterial partial pressure of oxygen to fractional inspired oxygen) after off-pump CABG.
Methods: Forty off-pump CABG patients were included in this prospective observational study in a tertiary care center from 2022 to 2023. The correlation coefficient from an earlier study was used and a sample size of 9 was calculated. Random sampling technique was used. A four-sector lung ultrasound was utilized for B-line scoring. B-line scores and PaO2/FiO2 ratios were recorded at three time points: before the surgery commenced and at 24 and 48 hours post-operation. The fluid balance was calculated at 24 and 48 hours post-operation. Pearson correlation coefficient was used to evaluate the correlation between B-line scores and fluid balance with oxygenation, and its significance was assessed through a linear regression test.
Results: The PaO2/FiO2 ratio and B-line scores exhibited a statistically significant moderate negative correlation at 24 hours post-surgery (r = -0.44; SD = -0.66, 95% CI = -0.66, -0.15; P = 0.004) and a B-line score exceeding 8 was associated with the lowest PaO2/FiO2 ratio. However, fluid balance and PaO2/FiO2 ratios revealed no correlation at 24 or 48 hours post-surgery. Additionally, fluid balance and B-line scores demonstrated a moderate positive correlation after 48 hours but no correlation at 24 hours post-surgery.
Conclusion: B-line scores always negatively correlated with PaO2/FiO2 ratios, and scores greater than eight corresponded to the lowest ratio.
Keywords
- Coronary artery bypass
- Lung ultrasound
- Extravascular lung water
- Fluid therapy
- Hypoxia
- Diuretics
- Partial pressure
Main Subjects
on oxygenation assessed by lung ultrasound in adult cardiac surgery. Cureus. 2020;12(8):e9953. doi: 10.7759/cureus.9953.
2. Davies OJ, Husain T, Stephens RC. Postoperative pulmonarycomplications following non-cardiothoracic surgery. BJA
Educ. 2017;17(9):295-300. doi: 10.1093/bjaed/mkx012.
3. Senniappan K, Sreedhar R, Saravana Babu MS, Dash PK, Gadhinglajkar SV, Sukesan S. Bedside lung ultrasound for
postoperative lung conditions in cardiothoracic intensive care unit: diagnostic value and comparison with bedside chest
roentgenogram. Anesth Essays Res. 2019;13(4):649-53. doi:10.4103/aer.AER_125_19.
4. Vetrugno L, Biasucci DG, Deana C, Spadaro S, Lombardi FA, Longhini F, et al. Lung ultrasound and supine chest X-rayuse in modern adult intensive care: mapping 30 years of advancement (1993-2023). Ultrasound J. 2024;16(1):7. doi:
10.1186/s13089-023-00351-4.
5. Basumatary K, Dey S, Neema PK, Mujahid OM, Arora P, Kalbande J. Incidence of postoperative pulmonary congestion
as diagnosed by lung ultrasound in surgeries performed under general anaesthesia: a prospective, observational study. Indian J Anaesth. 2023;67(7):628-32. doi: 10.4103/ija.ija_598_22.
6. Liu ZP, Zhang Y, Bian H, He XR, Zhou YJ, Wang LJ, et al. Clinical application of rapid B-line score with lung ultrasonography in differentiating between pulmonary infection and pulmonary
infection with acute left ventricular heart failure. Am J Emerg Med. 2016;34(2):278-81. doi: 10.1016/j.ajem.2015.10.050.
7. Smith BB, Mauermann WJ, Yalamuri SM, Frank RD, Gurrieri C, Arghami A, Smith MM. Intraoperative Fluid Balance
and Perioperative Outcomes After Aortic Valve Surgery. Ann Thorac Surg. 2020;110(4):1286-1293. doi: 10.1016/j.
athoracsur.2020.01.081.
8. Imanishi J, Maeda T, Ujiro S, Masuda M, Kusakabe Y, Takemoto M, et al. Association between B-lines on lung
ultrasound, invasive haemodynamics, and prognosis in acute heart failure patients. Eur Heart J Acute Cardiovasc Care.
2023;12(2):115-23. doi: 10.1093/ehjacc/zuac158.
9. D’Alto M, Di Maio M, Argiento P, Romeo E, Rea G, Liccardo B, et al. Right heart failure as a cause of pulmonary congestion in pulmonary arterial hypertension. Eur J Heart Fail. 2024;26(4):817-24. doi: 10.1002/ejhf.3172.
10. Palomba H, Treml RE, Caldonazo T, Katayama HT, Gomes BC, Malbouisson LM, et al. Intraoperative fluid balance and
cardiac surgery-associated acute kidney injury: a multicenter prospective study. Braz J Anesthesiol. 2022;72(6):688-94. doi:10.1016/j.bjane.2022.07.006.
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