Monday, April 16, 2018

Common Formulae for use in Paeds


 


COMMON FORMULAE :
                         
Many Drugs are given according to Surface Area of Pt.
Formula to Calculate Surface area from weight (x)  is :

S.A = (4x + 7) / (90 + x)
       = _____ m2

Fluid  rate

what are the formulas to calculate drops rate of a simple dripset, B.T set , and microburette ???

 In in simple drip set 15 drops = 1 ml
 In Blood Tx Set 12 drops = 1ml
 In microdrip set (pediadrip) 60 micro-drops =1 ml

Various Formulae are given below.

 1)   Simple Calculation Formula is:

                    Fluid in ml *drops/time in min


2) Drop index Formula is :

                   Fluid in ml ×drop index/time in min                    

  the drops will come out for one minute !
  drop index is 15 for dripset ,, 60 for M.B (pediadrip) and 10 or BT set.

3)  FOR BURETTE.. FLUIDS(ml)/TIME(hrs)

4) for DRIP.............FLUIDS(ml)/TIME(hrs) MULTIPLY BY 1/4.....e.g to give 500 ml in 8 hrs it will be approx 62 micro drop/min or 15 macrodrops.

Calculation of GFR
Many drugs , specially antibiotics need adjustment in their DOSES, or their INTERVALS of administration . This is decided on the basis of  GFR , which may be calculated as:

GFR = kL/SrCreatinine

Where K is constant
L is length/height
Sr creatinine

K values:

LBW infants in 1st year
0.33
Term AGA in first yr
0.45
Children and adolescent girls
0.55
Adolescent boys
0.70


Check at the end of Harriet Lane : Drugs in Renal Failure to see adjustment of DOSES, or intervals or BOTH.

No comments:

Post a Comment

Questions related to Patent ductus arteriosus

What is patent ductus arteriosus why is it more common in neonates What is frequency of patent ductus arteriosus opening after fluid bolus d...