The choice of fluids will often be determined by what is available. There are 3 types of intravenous fluid: crystalloid, colloid and blood ( table 2). Dextrose 5% is not effective in the treatment of shock as it leaves the circulation rapidly. It should only be used as a last resort.

Crystalloids are distributed rapidly between the circulation and the extracellular (interstitial) fluid. When treating shock give three times the estimated blood loss to allow for this. i.e. when replacing 1000mls blood loss give 3000mls of crystalloid.

Colloids remain within the circulation for a longer time (typically 4-8 hours) and should be administered in an equal volume to the blood loss.

Intravenous fluid replacement should be given to replace the estimated losses rapidly. Suitable fluid regimes for differing degrees of blood loss are shown in table 3. Many readers will not have access to colloids; the correct response is to give more crystalloid in a volume of three times the estimated loss, plus blood transfusion as described above. If facilities allow, warm the fluids (especially blood) using a blood warmer.

Monitor the patient's response to treatment by careful observation and recording of the clinical signs in table 1. Pass a urinary catheter and measure urine output to assist in your assessment. Aim for a urine flow of 0.5-1ml/kg/hour. Clinical improvement will be sustained if you have replaced the correct amount of blood and the rate of haemorrhage is lessening. When the patient fails to respond appropriately, consider whether there are other sources of haemorrhage that you have not identified, or that haemorrhage is continuing unabated into the chest or abdomen or pelvis. A tension pneumothorax, pericardial tamponade or cardiac contusion can compound the signs of shock. In these situations measuring central venous pressure (normal 4-10cmH₂0) is helpful as it will indicate if pump failure is present.

Investigations may be needed to assist the diagnosis of injuries eg chest or other X-rays. A haemoglobin or haematocrit estimation helps in the decision for blood transfusion, which should maintain the haemoglobin around 8-10g/dl. However, if the sample is taken before resuscitation, a misleadingly high result may be obtained as haemodilution will not have occurred. Occasionally the serum potassium levels may be altered.
 
Life saving surgery.

When there is severe haemorrhage (eg ruptured spleen or ectopic pregnancy) the patient may require an immediate operation to save life. Delaying surgery for prolonged resuscitation wastes resources and may be fatal.

Resources. In many parts of the world resources such as intravenous fluids or blood are in short supply. The sooner shock is treated, and the underlying cause diagnosed and managed, the better the outcome (and less resources consumed).
 
Summary.

The key to successful management of haemorrhagic shock is awareness, identification and careful assessment of the problem and treatment with adequate fluid replacement. Attention to the airway and ventilation with oxygen is vital. Early precise diagnosis and definitive surgery should follow rapid resuscitation.

This article contained links to the following additional information:

Table 1 - Clinical signs of shock
Figure 2 - Treating shock
Table 2 - Types of intravenous fluids used in shock shock
Table 3 - Suitable blood replacement regimes

©World Federation of Societies of Anaesthesiologists WWW implementation by the NDA Web Team, Oxford

---