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++)

SEVERE BURNS HAND - THUMB WITH CONTRACTURES...

 Hello,

My daughter who is volunteering in Indonesia sent me a photo yesterday of a little girl with a deformed thumb from an untreated burn injury.  She is asking if anything can be done for the child.

I have attached some pictures.

My daughter writes, "L.. is a little over one year old and the first burn incident happened when she was about 4 months and the second incident happened when she was about 8 months (she rolled into the fire.)"

Can you make a recommendation whether or not surgical intervention would be of benefit to her?

Thanks for you time,

Dr D W

Dear Dr D W
Thanks you very much for your letter,
so sad to see this wonderful child suffer from this burn,
nice to hear your daughter is doing charity work abroad,

L...has a burn which is quite severe,
the burns must have been full thickness and would have needed a skin graft during the time of the burn episode ,
as no addition of tissue was done it healed secondarily causing very severe burn contractures,

presently the contracture is severe as it appears,

its has distorted the thumb joints and if untreated will end in severe deformities in the future and she will  be unable to effectively use the thumb,

she needs surgery which will involve ,

releasing the thumb from its present position and getting it back to its normal position,

once done i think a large area of tissue defect will appear and this may need a thick pad of tissue with skin ( flap cover as it is called in plastic surgery ) rather than a thin skin graft, 

choices of flaps include - radial artery flap, abdominal flap and free flap depending on the expertise available

sometimes if we are lucky we may be able to get away with a skin grafting procedure,(this can be made sure of only at surgery),

we at asktheburnsurgeon hope that this sweet child can be helped somehow to regain back her function ....

with best regards

and wishes

asktheburnsurgeon++

Role of colloids in burn resuscitation...........

Doc, what is the role of albumin in early burn resuscitation? Do we have to give it in all cases?

Jessie p,

Colorado, USA

When a patient suffers a burn injury there is a temporary loss of the integrity of the capillaries as we have discussed before. This loss leads to the leakage of plasma proteins like albumin into the interstitial space.  This loss continues for the first eight hours following which the capillaries start to regain their integrity. Therefore if one were to replace the colloids in the first eight hours they would obviously leak out. It seems reasonable that one may start to replace giving colloids in the 2nd eight hours of the burn.

Different types of colloids may be used for resuscitation in burns: fresh frozen plasma, albumin and Dextran. Fresh frozen plasma is often given at a rate of 0.5ml-1ml/kg %TBSA and has a theoretical advantage - it replaces other plasma proteins besides albumin.

Dextran, another colloid used in burn resuscitation increases capillary blood flow, reduces RBC aggregation and helps to reduce tissue edema though this effect is limited to the time that Dextran is being administered as the body will metabolize it eventually. Dextran is composed of polymerized high molecular weight glucose chains and has double the osmotic pressure of albumin.

Hypertonic saline (180-300 mEq/L) has been used in some centers as it helps to shift extracellular fluids ( third space fluid loss) back into the vascular space by osmosis resulting in a reduction of fluid requirements. However there are some disadvantages: hypernatremia and intracellular fluid depletion can occur and therefore serum sodium levels should be closely monitored and maintained below 160mEq/L.

Albumin which is a regular component of our plasma is a protein that maximally raises the intravascular oncotic pressure. When it is given intravenously fifty percent of it remains intravascular, when compared to other colloid solutions where only twenty to thirty percent remains intravascular. Albumin is often infused as the rate of 0.3-1ml/kg /% burn over 24 hours.

In many centers colloids are added in the 2^nd eight hours though Parkland formula advocates only crystalloids in the first 24 hours.  Colloids help to reduce the fluid load in the first 24 hours and they also help to increase the urine output which often tends to go down during resuscitation. Colloid resuscitation is of great benefit in geriatric patients, major burns (>40%), patients associated with inhalation injury and those with cardiac disorders as it is difficult to resuscitate them with limited fluids and they are constantly in the danger of being overloaded. Fluid infusion should be tapered off after the first 24-32 hrs, when one finds that the patient has been adequately resuscitated. Fluid administration should then be planned on the basis of requirements of albumin (keep>2) and free water requirements (electrolyte free) to counter   irreversible water loss. Free water requirement is estimated as (25% + % burn) x BSA (m²) = ml/hr free water. The maintenance of all the clinical parameters like the urine output at normal levels is critical to the continuation of the resuscitation process to its logical conclusion. Prudent use of fresh frozen plasma and albumin can be very helpful and safe when compared to other colloids in burn resuscitation.

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

Monitoring the burn patient during burn resuscitation….

 Doc, we recently had a patient with 80 percent burns. Though we calculated the fluid loss and replaced it adequately the patient died. Could you tell us why this may have happened?

Sohail k,

Karachi, Pakistan.

Patient with major burns have two major issues that need to be dealt with:

a) Calculating the fluid requirement and replacing it

b) Monitoring the burn patient to know if the fluids replacements are adequate

We have already seen the calculation of fluids requirements in a previous post. We shall have a look at how to monitor burn patients. With fluid replacements there can be two issues- inadequate fluid replacement or fluid overload. If the calculated fluids are less then the patient will end up in shock and deteriorate. If the fluids are over calculated then fluid overload, increased pulmonary complications and increased compartmental pressure will result and finally end in circulatory failure and collapse.

All burn patients must therefore be monitored with great care.  A number of clinical parameters that are commonly used in ICU monitored patients are also applicable here:

Pulse

Temperature

Respiration

Blood pressure

Oxygen saturation

Central venous pressure

 Hourly urine output

These are the most common clinical parameters used. As the body looses fluids from burns and the intravascular pressure falls from the fluids shifts the blood pressure tends to fall. However the human body has a lot of inbuilt mechanisms to control this fall and deceptively maintains the blood pressure by releasing catecholamines or chemicals which will cause contraction of the blood vessels and thereby maintain the blood pressure. The pulse also rises from the pain reaction (tachycardia). The body has a limit till which it can support the blood pressure, once the fluid loss crosses this limit the homeostatic mechanisms will fail and  burn shock will result. The increasing compartmental edema that results in burns can result in an erroneous blood pressure reading. Similarly the vasospasm that occurs in the extremities can lead to incorrect oxygen saturation reading by pulse oxymetry.

Urine output is one of the most important parameters while monitoring the burn patient and this should be 0.5ml (kg/hr) in adults and in children    about 1ml (kg/hr). In most cases if an adequate urine output is maintained one can assured of an adequate fluid resuscitation. Major burn patients will need placement of a urinary catheter to monitor the hourly urine output. The volume status can also be gained from the central venous pressure or CVP. Insertion of a cvp line helps in monitoring this pressure and helps prevent fluid overload in normal patients. However in patients with previous poor cardiac function or in geriatric patients one may need the use of a swan ganz catheter. Similarly diabetic patients and those using long term diuretics and also patients with resuscitation difficulties may benefit from the use of the swan ganz catheter. Pulmonary vasoconstriction may lead to faulty CVP or swan ganz measurements. Maintenance of the acid base balance in the body as seen from the various blood gas measurements and analysis suggest adequate resuscitation. Some patients with cardiac co morbidities may need invasive cardiac monitoring. In these patients one must be careful while increasing the fluid administered and should only be done gradually to maintain adequate urine output (0.5ml/kg/hr adult and 1ml/kg/hr in children).

The requirement of fluid may be higher than calculated in some patient groups. Those patients who have suffered inhalation injury need 30-40%more fluids than suggested by Parkland formula. Patients with electrical burns need more fluids as they have greater underlying tissue damage. Patients undergoing diuretic therapy have prior free water deficits and need more fluids for resuscitation. Patients who have undergone escharotomies and have large open wounds may have higher free water losses that need to be adequately replaced. Patients in whom resuscitation is delayed probably have higher inflammatory response, greater fluid needs and attempts should be made to replace the fluid deficit calculated by Parkland in the immediate resuscitation period without causing hemodynamic failure.

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