No abstract

Half-molar lactate solution is effective for fluid resuscitation in post-CABG patients. Compared to Ringer's Lactate, its use results in a significantly higher cardiac index with less volume being infused, resulting in a very negative post-operative body fluid balance.

Although hypertonic saline has been proposed as an intravenous resuscitation fluid, the beneficial effects of the sodium load are associated with potentially deleterious effects of chloride. Since the physiological lactate anion is well metabolized, hypertonic lactate solution could represent an interesting alternative. The aim of this study was to compare metabolic and hemodynamic effects of hypertonic infusion of sodium lactate versus sodium chloride in three groups of surgical patients who underwent elective coronary artery bypass grafting (CABG). Hypertonic lactate solution was infused to patients 14 to 16 h after surgery either involving a cardiopulmonary bypass (CPB-Lac, n = 20) or on-off pump (OPCAB-Lac, n = 20), whereas the third group consisted of patients undergoing cardiopulmonary bypass but receiving hypertonic saline solution (CPB-NaCl, n = 20). An equal fluid and sodium load (2.5 mL/2.5 mmol x kg(-1)) was infused in all patients over 15 min. Plasma glucose and sodium increased after infusion in the three groups, but the changes, although significant, were small. As expected, lactate rose only in CPB-Lac and OPCAB-Lac groups, the changes being more marked in CPB-Lac, indicating a slower lactate metabolism in this group compared with OPCAB-Lac. Although both solutions produced significant increases in cardiac index and oxygen delivery, there was a significant decrease in oxygen extraction only in groups receiving sodium lactate (CPB-Lac and OPCAB-Lac) and not in CPB-NaCl. Finally, hypertonic NaCl infusion induced a modest, although significant, decrease in arterial pH and bicarbonate, whereas hypertonic lactate infusion increased these two parameters in both CPB-Lac and OPCAB-Lac. This study demonstrates that hypertonic lactate infusion is safe and well tolerated in patients undergoing elective cardiac surgery.

While surgery and anesthesia per se do not seem to alter lactate metabolism, CPB significantly decreased lactate clearance, this effect being possibly related to a mild liver dysfunction even in uncomplicated elective surgery.

No abstract

Shifting the substrate metabolism from lipids to carbohydrates and reinforcing the antioxidant status reduces the deleterious biological and clinical consequences of acute ischaemic events. The use of the glucose-insulin-potassium infusion has become widespread with the re-discovery of its value in modulating cellular metabolism and accelerating recovery of the ischaemic myocardium. Antioxidants have gained acceptance in the perioperative phase, as well as in chronic heart failure. This constitutes another piece of evidence in favour of early metabolic and nutritional intervention. There also appears to be room for the prevention of acute deterioration of cardiac function after surgery with the preoperative administration of oral supplements containing omega-3 fatty acids.

Most physicians involved in intensive care consider lactate solely as a deleterious metabolite, responsible for high morbidity and bad prognosis in severe patients. For the physiologist, however, lactate is a key metabolite, alternatively produced or consumed. Many studies in the literature have infused animals or humans with exogenous lactate, demonstrating its safety and usefulness, but the bad reputation of lactate is still widespread. The metabolic meaning of glucose-lactate cycling exceeds its initial role described by Cori and Cori. According to recent works concerning lactate, it can be predicted that a new role as a therapeutic agent will arise for this metabolite.

The rapid economic, scientific, and technologic development in Asia probably is the most important in the world today. Eventually, the development of health care and critical care medicine in the Western Pacific will be affected. Even with the problems that have to be faced, the future of critical care medicine in the region looks promising.However, the leaders of critical care medicine in each country should identify the model of intensive care practice that is the most appropriate for their country. Each country needs to assign an appropriate rank of priority to intensive care. There is a great need for simple, inexpensive therapeutic interventions and methods for monitoring critically ill patients that can be shown to be effective. Efficient systems for transporting critically patients are also needed. Simple ventilators with inexpensive monitors and defibrillators are the technology that is most needed. Good referral systems and greater use of physician extenders, such as nurse practitioners, to provide enhanced access to specialist care for critical illness should be promoted. A few high-standard ICUs with good facilities for education and training should be organized on a regional basis in each country.