tailieunhanh - How to Survive in Anaesthesia - Part 3

Hai giải pháp phổ biến có sẵn là giải pháp và natri clorua 0,9% dung dịch Hartmann. Lactate trong dung dịch Hartmann hoặc bị oxy hóa trong gan, hoặc trải qua gluconeogenesis. Cả hai con đường trao đổi chất sử dụng các ion hydro để alkalinisation nhẹ xảy ra. Điều quan trọng là phải nhớ rằng cả các giải pháp này thêm ít tích máu nội mạch | emedicina How to Survive in Anaesthesia confined to the extracellular space in a ratio of 1 3 in terms of intravascular interstitial volume. The two commonly available solutions are Hartmann s solution and 0-9 sodium chloride solution. The lactate in Hartmann s solution is either oxidised in the liver or undergoes gluconeogenesis. Both metabolic pathways use hydrogen ions so that mild alkalinisation occurs. It is important to remember that both these solutions add little to the intravascular volume. Glucose-containing solutions It is difficult to make a case for continuing to use these solutions. The stress of surgery increases circulating blood glucose so that the addition of more glucose intravenously exacerbates the metabolic insult. Furthermore when glucose is eventually oxidised to water and carbon dioxide the infusion is then equivalent to water only 5 glucose or a very weak hypotonic solution 4 glucose 0-18 sodium chloride solution . The main reason for continuing to use these solutions seems to be fear of the phase of sodium retention that inevitably accompanies surgery. Since low plasma sodium concentrations are almost invariably found postoperatively this fear is unsubstantiated - patients usually need more sodium. Only a small proportion of glucose-containing solutions stay within the intravascular space they are of little value in maintaining the blood volume. The composition of commonly used intravenous fluids is shown in Table . Colloids These are large molecules suspended in solution. They generate a colloid osmotic pressure and are confined to the intravascular space. Table Electrolytic composition of intravenous solutions mmol l Solution Na K Ca Cl Lactate 0-9 Sodium chloride 150 150 Hartmann s solution 131 5 2 111 29 5 Glucose 4 Glucose in 0-18 NaCI 30 30 Gelofusine 154 125 Haemaccel 145 5 6 145 Hydroxyethyl starch 154 154 26 emedicina Intravenous fluids Table Properties of colloid solutions . Plasma t h Elimination Anaphylaxis .