Intravenous Therapy and Infusion Devices

Fluid balance in man • It is a balance between intake and loss (Figure 9.1). • Intake is from the normal diet (food and drink), and loss is mainly due to excretion as urine and faeces. Loss is also from sweat (skin) and water vapour from the lungs. The last two are difficult to measure and so are termed insensible losses and are based on approximations.