Fluid therapy is the initial cardiovascular intervention in most cases of shock, with the exception of cardiogenic and obstructive shock.
A fluid challenge of about 10 - 20 ml/ kg is a good start depending on the degree of shock.
E.g. initial fluid therapy for a 30 year old male in septic shock at the progressive stage (see page 8) would benefit from an infusion of 20ml/kg of Ringers lactate or 10ml/kg of colloid over 10-15 minutes. The patient should be continuously observed and repeatedly examined to identify changes in condition in response to the fluid administered. Does the blood pressure improve? Does the heart rate slow down? does the CVP go up? How much does the CVP go up by? Does peripheral perfusion improve? Although it might be delayed, does the urine output improve? Is lactate level lower? is there an improvement in metabolic acidosis?
The fluid therapy regime described above might have to be repeated. It is often necessary to start the administration of inotropes/vasopressor as fluid optimisation is taking place. If the patient's condition does not improve quickly with 10-20 ml/kg of fluid you should contact senior help if you haven't already done so. Persevering with the administration of bag after bag of fluid without the correction of shock or seeking senior advice is a common cause of deterioration in patients with shock.
1. Use your clinical judgment and seek senior help, below is a rough guide. You should not administer any fluid without thinking of the consequence!
2. As a rough guide, administer 10-20 ml/kg of fluid to patients in hypovolaemic or distributive shock depending on stage of shock (see page 8)
3. If there is not response quickly call senior help as inotropes/vasopressors might be required
4. If hypovolaemic shock is due to haemorrhage replace blood loss with blood. if bleeding is ongoing consider activating the major haemorrhage protocol and seed senior help
5. Compared to crystalloids, colloid expand the circulating volume by approx. 1.5 times.