Burns in children……

Fluid resuscitation in pediatric population

Doc, are burns in small children more serious than in adults? Also please tell how does the resuscitation of burn patients differ in adults and in children?

Milnarnake p,

Sri Lanka.

Management of burns in children differs significantly from that in adults. This is because the fluid loss in burns depends on the total body surface area that is burnt and the calculation of the body surface area is different in adults and children. When compared to adults it has been found that children have larger head and smaller thighs. Thus while in adults the head is taken as 9 percent in a newborn or infant it is 20 percent TBSA. Similarly the lower limbs account for 18 percent in adults, however in an infant it accounts for only 13 percent TBSA, since the infant has a smaller limb size compared to adults in proportion to the head. Again the upper limbs account for 9 percent each in adults, but in children this is only eight percent. In adults the front and back of the body or trunk account for 18 percent but in infants it is 20 percent.

Thus in an infant

Head – 20

Both upper limbs – 8x2=16

Both lower limbs 13x2=26

Back of trunk -18-20

Front of trunk – 18-20

This all approximates to about 100 percent

To get the most accurate calculation in children the Lund and Browder chart should be used.

Urine output/hour which is one of the most important clinical parameter in monitoring burn patients should be 1 ml/hr in children as compared to adults (0.5 ml/hr). Children who are over 50 kg should be managed as adults for calculating the fluid requirement. Minor burns in children (less than 10% usually do not need any fluid resuscitation as the body can handle this fluid loss. However children with over 10% burns need fluid resuscitation as compared to adults over 15%. The requirements in children are higher and most centers add maintenance fluids to their resuscitation formula.

It is interesting to note that if the parkland formula as used in adults

 i.e. 4x %TBSA x body weight is used in children, the fluid calculated will be inadequate and therefore a modified parkland formula is used in children-

3 x %TBSA x body wt + daily maintenance fluid requirements

How do we calculate the daily fluid requirement in a child? Here’s a simple method:

First 10 kg- 100ml/kg

Second 10 kg- 50ml/kg

Rest of kgs- 20 ml/hr

This is the total maintenance fluid requirement for 24 hrs and this is divided by 24 or 25 to get the per hour calculation

Imagine a child with 25 kg- what is the maintenance fluid requirement for 24 hrs?

First 10 kg- 100ml/kg i.e.  10x100 =1000ml

Second 10 kg- 50ml/kg i.e. 10 x50= 500ml

Rest of kgs- 20 ml/hr i.e.      5x 20= 100ml

                                      Total = 1600ml for 24 hours

This maintenance fluid should be added to the burn fluid requirement – say for example this 25 kg child had 25 percent TBSA burn

i.e. using parkland formula

3x 25x 25

=1875ml add the maintenance 1600 ml

Total= 3475ml in 24 hrs

Divide by 2= 1738 ml in first 8 hrs or divide this by 8= 217 ml each hr for the first 8 hrs

For the next sixteen hrs the fluid will be 1738/16 i.e. 108ml per hour for the next sixteen hours.

This is only a calculation done as a guideline and should not be rigidly adhered to. We at asktheburnsurgeon are comfortable with the modified parkland formula and the fluid requirements as done above. We also add a small dose of albumin or fresh frozen plasma from the second eight hours to help build up the oncotic pressure that is lowered due to loss of plasma proteins.

Urine output in adult burn patients should be around 0.5ml/kg/hr- 1ml/kg/hr

In children this should be around 1ml/kg/hr

Therefore a 25kg child should produce at least 25 ml urine per hour

While in an adult of 50 kg a urine output of 25-30ml would be just acceptable

The clinical parameters and the urine output per hour should be kept in mind and the fluid requirement can be increased or decreased to maintain all the clinical parameters in the normal range. The monitoring should be done as in adults.

Children are more susceptible to burn shock and therefore IV access should be rapidly obtained. Rarely an interosseus live may be needed when these lines cannot be obtained. Glucose levels should be frequently checked since hepatic glycogen levels are limited in children, and addition of D5 Ringer lactate solution can help in preventing troublesome hypoglycemia.

 (An original initiative in burn care and education from asktheburnsurgeon++)