lvstar.blogg.se - Practical guidelines on fluid therapy pdf

More about intravenous fluid composition can be found in detail here.Īs an example, let us say that our patient is a 70kg healthy male*.

Colloids – Colloids have a high colloid osmotic pressure and theoretically should raise the intravascular volume faster than their crystalloid counterparts, yet clinical trials have not shown any significant benefit or effect in practice so their use in many hospitals is decreasing.

Therefore, crystalloids are used very commonly in the acute setting, in theatres, and for maintenance fluids.

Crystalloids – Crystalloids are more widely used than colloids, with research supporting the idea that neither is superior in replenishing intravascular volume for resuscitation purposes (with crystalloids also significantly cheaper).

IV fluids can be broadly categorised in to two groups, crystalloids and colloids (as detailed in Table 2): You will find numerous ways of calculating the daily requirements of these 4 components and they are invariably based on the patient’s weight.Ĭurrent NICE guidelines suggest the following:īased on these required, it is necessary to consider the fluids that are available for prescription and what exactly they contain, to be able to prescribe appropriately Intravenous Fluids Patients do not just require water, they also need Na +, K +, and glucose replacing too, particularly if they are nil by mouth. In such patent, monitor the electrolytes and allow this correction to occur, as this is normal and is to be expected (rarely will supplementary IV fluids will be warranted in such cases).

They therefore often “correct themselves” and urinate out the excess fluid that was previously required to maintain their intravascular volume and tissue perfusion. When patients start to clinically improve, their vascular permeability returns to baseline state. These factors should be taken into account when deciding how much fluid a patients needs replacing.

Losses from non-urine sources are termed insensible losses insensible losses will rise in unwell patients, who may be febrile, tachypnoeic, or having increased bowel output. Hence, when a patient is nil by mouth (NBM), it is important that all sources are replaced via the parenteral route. Only 3/5 th of our fluid input comes through fluids via the enteric route, with the remainder from both food and metabolic processes. The actual amount varies considerably depending on physiological status and body weight (which in adult patients can vary from around 40kg to 200kg). Note that these figures are the average for a 70kg man. Table 1 – Guide to the sources of fluid input and output *After some operations, patients are deliberately run “on the dry side”, whilst septic patients or patients in bowel obstruction will need aggressive fluid prescribing. What were their most recent electrolytes?.What is their underlying reason for admission*?.Are there any co-morbidities present that are important to consider, such as heart failure or chronic kidney disease?.The fluid requirements of a frail 45kg 80yr female and a healthy 100kg 40yr male will be significantly different.What is the weight and size of the patient?.Is the aim of the fluid for resuscitation, maintenance, or replacement?.The general key considerations to remember with every patient are: Perhaps the most important point to remember therefore is that correct fluid prescription varies depending on the individual patient and it is essential to take individual patient characteristics into account before prescribing fluid. The relative importance of each of these varies between patients. Introductionįirstly it’s important to think about why fluids should be prescribed in the first place. *Please be aware that this article talks solely about adult fluids and does not cover paediatric prescribing. Fluid management is a major part of junior doctor prescribing whether working on a surgical firm with a patient who is nil-by-mouth or with a dehydrated patient on a care of the elderly firm, this is a topic that a junior doctor utilises on a regular basis.Įnsuring considered fluid and haemodynamic management is central to peri-operative patient care and has been shown to have a significant impact on post-operative morbidity and the length of hospital stay. Hence it is essential to gain a firm understanding of the physiology of fluid balance and the compositions of each fluid being prescribed.