Water constitutes 45-65% of the total human body weight. The amount of water depends mainly on the age of the individual. Therefore, it is crucial to maintain homeostasis of the human body as homeostasis excludes any disturbances in the functioning of the organism, including the disturbances caused by loss of water or other body fluids. Due to some diseases, prior clinical surgeries, and injuries, it may be necessary to externally support the physiological functions of the body by means of delivering fluids through the circulatory system in order to maintain its proper functioning. In the medical field, such activities are called fluid therapy (1).

The main goal of fluid therapy is the supplementation of the vascular bed, which consequently contributes to a stabilization of preload. A significant advantage of fluid therapy is the almost immediate body response. The procedure is undoubtedly justified by the positive reaction (a stabilized pulse, general beneficial effects on health, an increased blood pressure values) to fluids. However, if the patient’s condition deteriorates immediately after such a positive reaction, the medical team performing fluid therapy should continue it by further delivering fluids and simultaneously diagnose the cause of their loss (2).

Nowadays, fluid therapy is mainly associated with the tasks performed by doctors and nurses specialized in anesthetics. The reason is that fluid therapy is one of the most frequent methods applied in the professional tasks of this group of specialists. However, this therapy is also applied as a part of prehospital- and hospital treatment, e.g. in emergency medicine departments (3). Fluid therapy is used when it is required to stabilize blood volume and restore a proper level of oxygen content in cells and tissues. Moreover, fluid therapy is perceived as a justified supplementary procedure in cases of threat of life or health in order to stop the potential coagulation disorders and to protect proper physiological renal functions.

In spite of the significance of fluid therapy, which is undoubtedly an important element of patient’s care when fluid therapy is required, medical professionals emphasizes other equally important aspects called ABC. According to them, it is necessary to secure the respiratory tract, providing ventilation if required in the specific situation, and to secure circulation by means of using two or more peripheral venous access elements.

– A – B – airway – breathing,

– C – circulation (4).

The basic indications for the application of fluid therapy in the treatment of an injured patient are traumas causing loss of blood or other body fluids. In both prehospital care and hospital emergency treatment, traumas are one of the major indications for including fluid therapy in the process of treatment. Hypotension (caused by a hemorrhage, a serious dehydration or other factors) also constitutes a clear reason to apply fluid therapy while providing assistance in hospital emergency departments. Moreover, basic recommendations also include continued prehospital treatment activities and further actions in the form of fluid resuscitation in cases of e.g. sudden cardiac arrest (5). Apart from the above mentioned indications, there are more to be found in the specialized literature. Frequent indications for fluid therapy include:

– shock: any types of shock. The most frequent is the hypovolemic shock. The group also includes the anaphylactic shock and the septic shock,

– burns: a loss of liquids caused by a higher permeability of blood- and lymphatic vessels,

– dehydration caused by an increased loss of liquids due to e.g. diarrhea, vomiting. It is especially in pediatric patients that these factors are serious because of the risk of a sudden life threat condition,

– other cases of liquid deficiency in the body (6).

A formulation of the major indications for fluid therapy in an injured is a crucial assistance for the individuals who provide medical care. In spite of numerous articles and case studies, fluid therapy remains the subject of further new research and discussion. One of the main aspects considered in the context of fluid therapy is the proper selection of the infusion fluid (7).

The current literature considers the best infusion fluid available on the market. The major requirements identified by medical professionals are:

– the fluid should improve perfusion after the application of a low volume of the fluid,

– the fluid should have a beneficial effect on the oxygen management (i.e. the levels of oxygen uptake and delivery to the body),

– the fluid should be composed of elements defined by other regulations (pH, electrolyte volume),

– the fluid should have as long duration of action as possible (8).

Crystalloids are infusion fluids composed of electrolytes or carbohydrates. The major indications for the application of crystalloids in fluid therapy are securing basic demand for liquids, compensating for losses of liquids, and eliminating electrolyte disorders in the organism. Inspite of the significant role of this group of fluids in the fluid therapy procedures, there are numerous negative aspects having a direct impact on the condition and the life parameters of the patient. The most important issue related to crystalloids is that the solution remains in the bed for a very short time. It has been estimated that, about 60 minutes after the injection, there is only 20% of the initial volume of the fluid in the vessels. It is caused by the possibility of diffusion through capillaries. About 80% of the volume delivered to the patient remain outside of the blood vessels and do not compensate for the losses. Another aspect of crystalloid-based fluid therapy that can be unpleasant to the injured is the risk of edema caused by a high amount of sodium in the solution. Currently, the most frequent crystalloids are e.g.:

– 5% glucose,

– 0.9% NaCl,

– Ringer’s lactate,

– Ringer’s solution,

– multielectrolyte fluid,

– sterofundin.

They are all characterized by a close relationship of plasma content to ions. In cases of loss of electrolytes caused by vomiting and diarrhea, 0.9% NaCl fluids are recommended (9). Nowadays, there are numerous medical products that meet the requirements on the Polish pharmaceutic market. One of the leading producers is Baxter. Natrium Chloratum 0.9% (Baxter) is an example of a ready and balanced fluid used in cases of serious loss of electrolytes.

Another group of fluids applied in fluid therapy is the group of colloids. Their major feature is that they elevate oncotic pressure and, as a consequence, water is transported to blood vessels. This phenomenon provides a very effective and prompt therapeutic effect. As estimated in the literature, 1 l of colloids equals 4 l of crystalloids. Despite the effectiveness of colloids, the indications for their use are insufficient supply of crystalloids and any contradictions related to the application of crystalloids (e.g. the risk of pulmonary edema).

Colloids have been divided into two groups based on their origin, i.e.:

– natural colloids, e.g. albumins,

– synthetic colloids (gelatins, starch solutions, and dextrans).