Changes in blood oxygen transport function and body energy expenditure during anaesthesia during coronary artery bypass grafting in adults: A randomized clinical study

Abstract

<b>Introduction:</b> Cardiac surgery is a dangerous and complex field of medicine with significant morbidity and mortality. Quality anesthetic care with specific attention to detail can greatly enhance patient safety and outcome.<br /> <b>Objectives: </b>Comparison of the effects of anesthetics on oxygen consumption, transport and energy expenditure during coronary artery bypass grafting in adults.<br /> <b>Material and methods: </b>A total of 90 patients were assigned randomly into three groups according to the type of anaesthesia: the first group with propofol (P), the second group with sevoflurane, and the last one was with isoflurane. All patients underwent coronary artery bypass grafting under cardiopulmonary bypass. To determine oxygen delivery and oxygen consumption were determined using the formulas ((DO<sub>2</sub> = CI* CaO<sub>2</sub>), (VO<sub>2</sub> = Cardiac index (CI)) and a spirometric device during anaesthesia.<br /> <b>Results: </b>the cardiac index remained at the same level in the propofol and sevoflurane groups (2.5±0.6 l/min/m2 and 2.3±0.5 l/min/m2), while in the isoflurane group it was decreased to 2.3±0.5 l/min/m2. The oxygen transport index was 421.6±57.0 ml/min/m2 in the propofol group, 396.4±63.2 ml/min/m2 in the sevoflurane group, and 376.7±68.0 ml/min/m2 in the isoflurane group. Propofol reduced oxygen consumption to 101.5±23.5 ml/min/m2, while sevoflurane and isoflurane anesthesia reduced it to 106.6±22.3 ml/min/m2 and 116.4±21.4 ml/min/ m2. All anaesthetics reduced energy expenditure, but propofol anaesthesia significantly reduced it from 1491.4 to 1188.3 kcal/day.<br /> <b>Conclusion: </b>In conclusion, isoflurane significantly reduced cardiac index compared to propofol and sevoflurane. Oxygen transport was higher in the propofol group than volatile anesthetics, and propofol reduced oxygen consumption more than inhalational anesthetics. In addition, energy expenditure was lowest in the propofol group than in the other anesthetics.