(d) Monitoring of shock

• After initial fluid resuscitation. Evaluate the patient at 1 - 2 hours. If the rate of IV fluid cannot be reduced to <10 ml/kg/hr. because of unstable vital signs (still narrowing of pulse pressure and rapid and weak pulse), Repeat the Hct:
  
• If there is an increase, change IV fluid to colloidal solution (Dextran-40 is preferred) at a rate of 10 ml/kg/hr.
  
• If there is a decrease, change IV fluid to colloidal solution (Dextran-40 is preferred) at a rate of 10 ml/kg/hr. and cross match for fresh whole blood (FWB) and re-evaluate the patient again after one hour whether he needs blood transfusion or not.
  
• In grade IV patients,
  
• If the initial Hct is very low, i.e. 40% - 45%, think of possible internal haemorrhage and follow Hct more frequently and give blood transfusion as soon as indicated.
  
• Correct the possible metabolic and electrolyte disturbance, e.g. hypoglycemia, hyponatremia, hypocalcemia, acidosis.
  
• After 6 hours, if Hct is decreasing and in spite of a large amount of volume replacement, still cannot reduce the rate of IV fluid to <10/ml/kg.hr., consider blood transfusion as soon as possible.
  

The recommended colloidal solution

• Dextran-40 (10% dextran-40 in NSS which is a plasma expander) is recommended because of its hyperoncogenicity (osmolarity ~3 times that of plasma), so it can hold the volume better. Other colloidal solutions, including plasma itself, are the plasma substitute and have osmolarity ~ 1 - 1.4 times that of plasma.
  
• The rate of dextran-40 should be 10 ml/kg/hr so that it can maintain mazimum osmolarity when administered to the patients.
  
• The maximum dosage of dextran-40 is 30 ml/kg/day. Do not exceed this amount for it may cause acute renal failure.
  

Duration of IV fluid

• The duration of IV fluid administration should not exceed 24 - 48 hours.
  

Indication for blood transfusion

• Significant amount of blood loss, i.e. > 10% of total blood volume (TBV). TBV = 80 ml/kg. Give FWB replacement equal to the amount observed.
  
• Patients with haemolysis due to their underlying diseases, e.g. G-6-PD deficiency, thalassemia.
  
• Patients with concealed bleeding. Hct fropped and unstable vital signs in spite of large amount of volume replacement, give FWB 10 ml/kg/dose or pack red cell (PRC) 5 ml/kg/dose at a time.