CARDIOVASCULAR JOURNAL OF AFRICA • Volume 35, No 3, September – October 2024 172 AFRICA Effect of lactate levels on extubation time in coronary artery bypass grafting surgery Selen Öztürk Abstract Aim: In current practice, fast-track protocols are gaining importance in patients undergoing cardiac surgery. For this purpose, besides different application techniques, biomarkers are frequently examined in the peri-operative period. We aimed to examine whether serum lactate levels at different peri-operative intervals had an effect on the extubation time. Methods: The patients were analysed in two groups according to the extubation time (early < 6 hours, and late extubation > 6 hours). Individual characteristics, co-existing diseases, blood transfusion, inotropic support, intra-aortic balloon pump, cardiopulmonary bypass time, aortic cross-clamp time, and the serial measurements of serum lactate levels were recorded. Correlations of serial measurements of lactate levels and the peri-operative variables with extubation times were analysed. Results: No significant differences were observed between the groups in terms of co-existing diseases and individual characteristics. However, cardiopulmonary bypass, aortic cross-clamp times and all lactate levels after aortic crossclamping were found to be significantly different (p = 0.001). A statistically significant correlation was found between the cut-off value of 1.7 for serum lactate levels after aortic-cross clamping (L2); 1.9 for levels after aortic cross-clamp removal (L3); 2.2 for levels after cardiopumonary bypass (L4); 2.1 for levels after intensive care admission (L5); 1.7 for levels after first postoperative hour in the intensive care unit (L6), and 1.8 for the difference between pre-operative levels (L0) and the peak level of lactate in the peri-operative period (ΔL) in predicting extubation time (p < 0.01). Conclusion: We concluded that cardiopulmonary bypass and aortic cross-clamp times, and intra-operative serum lactate levels were important in predicting early extubation after isolated coronary artery bypass graft surgery. Keywords: cardiac surgery, lactate, early extubation Submitted 15/3/23; accepted 3/5/23 Published online 5/6/23 Cardiovasc J Afr 2024; 35: 172–176 www.cvja.co.za DOI: 10.5830/CVJA-2023-027 Cardiac surgery practices have changed and developed over time. Studies have been conducted to reduce the extubation time by abandoning high-dose and opioid-based anaesthesia, which is performed to suppress the stress response to surgery and to provide haemodynamic stability.1 In a study conducted with the ‘fast-track protocol’ in the 1990s, the extubation time was reduced from 22.1 to 15.4 hours.2 Over time, the traditional or late extubation practice has moved toward early extubation. There have even been studies on ultra-fast-track protocols (in the operating room or within one hour).3 In cardiac surgery, early extubation causes a significant reduction in length of mechanical ventilation and intensive care unit (ICU) and hospital stay.4 Also, Camp et al.5 showed in a study of 2 211 patients that early extubation was associated with a reduction in cases of pneumonia and sepsis, length of stay in ICU/hospital, and re-intubation time. Borracci et al.6 stated that early extubation did not adversely affect clinical results in patients over 70 years of age and at low to intermediate risk. However, Richey et al.7 suggested that the early extubation protocol shortens the ventilation time, but prolongs the length of stay in the ICU. However, many studies have been conducted to examine possible factors to determine early extubation criteria.8-10 In current practice, techniques or protocols that shorten the duration of surgical and interventional procedures and therefore reduce the length of ICU/hospital stay and thus cost, are gaining importance. In this sense, biomarkers, especially those that can be studied routinely, constitute a serious field of study. Therefore, in our study, we determined whether lactate levels obtained by arterial blood gas analysis at different peri-operative times would predict extubation time. Methods After the approval of the local ethics committee (decision no: 2019/0325, date: 28/08/2019), we reviewed the files of patients who had undergone open-heart surgery between January and December 2018 at our hospital. Patients older than 18 years who had undergone isolated coronary artery surgery were included in the study. Patients who had undergone isolated valve surgery or concomitant valve surgery with coronary artery surgery and vessel surgery were excluded. Additionally, emergency surgeries, off-pump coronary artery surgery, and patients who had died were not included. At the same time, patients who developed postoperative complications (cardiac output, severe anaemia, mesenteric ischaemia, septic shock, renal failure and pancreatitis), which could have caused an increase in lactate level were also excluded. Age, gender, body mass index (BMI), ejection fraction (EF, %), pre-operative haemoglobin (Hb) value, and the number of vessels intervened in were recorded manually from the patient files or from the electronic system. In addition, data on co-existing diseases, such as diabetes mellitus (DM), hypertension (HT), chronic obstructive pulmonary disease (COPD) and atrial fibrillation (AF); whether blood transfusion, inotropic support and intra-aortic balloon pump (IABP) were applied; and Cardiovascular Surgery Clinics, Dr Siyami Ersek Thoracic and Cardiovascular Surgery Education and Research Hospital, Istanbul, Turkey Selen Öztürk, MD, drselen1980@gmail.com
RkJQdWJsaXNoZXIy NDIzNzc=