Watch “Oxygen Administration- SIMPLE FACEMASK” on YouTube

Simple facemask

Good friends!

Here is another interesting and educative teaching on my YouTube channel for this week.

Please watch it and subscribe to my YouTube channel (if you haven’t done so) and feel free to share on any social media platforms you belong.

Drop your comments and questions too.

Thank you.

Ogunlabi David.

Watch “Oxygen administration- nasal prongs” on YouTube

This is the first video on my YouTube channel. It explains the indications for oxygen administration, the overall goal of oxygen administration; it gives clarity on the difference between nasal prongs, nasal cannula and nasal catheters. And lastly it describes the basic things we need to know as nurses when administering oxygen therapy to patients using the nasal prongs.

Nasal prongs

Please watch this video and remember to press the SUBSCRIBE button so you can get the notifications for subsequent videos.

davidthenurse

CALCULATING A CHILD’S DOSAGE USING AN ADULT DOSAGE.

Child’s dosage= (Child’s BSA ÷ 1.7) * Adult dosage

Example 1:
The normal adult dosage of a medication is 150mg. The child weighs 32kg and is 120cm tall. How much medication should be given to the child?

Weight= 32kg
Height= 120cm
Child’s BSA= sq root [(weight in kg*height in cm)]÷3600
= sq root [(32*120)÷3600]
= sq root [3840÷3600]
= sq root [1.07]
= 1.03 sq meter
Child’s BSA= 1.03 sq meter

Adult dosage= 150mg

Child’s dosage= (Child’s BSA ÷ 1.7) * Adult dosage
= (1.03÷1.7) * 150
= 0.6058823*150
= 90.88
Child’s dosage= 90.88mg

Example 2:
Give Phenergan for a child whose BSA is 1.2 sq meter. The usual adult dose is 25mg. How many mg would the nurse administer for the dose?

Child’s BSA= 1.2 sq meter
Adult dose= 25mg

Child’s dosage= (Child’s BSA ÷ 1.7) * Adult dosage
= (1.2÷1.7)*25
= 0.7058823*25
= 17.65
Child’s dose= 17.65mg

OGUNLABI, David (RN)

CALCULATING BODY SURFACE AREA (BSA).

Body Surface Area (BSA) is very important in pediatric drug dosage calculation.

There are two formulae that are generally used to calculate a child’s BSA.

1. BSA= Sq. Root [(weight in kg * height in cm) ÷ 3600]
This is used when the weight is expressed in kilogram (kg) and the height is expressed in centimeter (cm).

2. BSA= Sq. Root [(weight in pounds * height in inches) ÷ 3131]
This is used when the weight is expressed in pounds (lbs) and the height is expressed in inches (in)

Example 1:
Calculate the BSA of a child who weighs 65lbs and 5feet 8inches tall.

Weight= 65lb
Height= 5ft 8in
Convert 5ft to inches, then add it to 8in
1ft= 12in
5ft= 5*12= 60in
Height= 60 + 8= 68in

BSA= Sq. Root [(weight in pounds * height in inches) ÷ 3131]

BSA= Sq.root [(65*68)÷3131]
= sq.root [4420÷3131]
= sq.root [1.41]
= 1.19
BSA of the child is 1.19 sq meter

Example 2:
Calculate the BSA of a child who weighs 11.3kg and 75cm tall.

Weight= 11.3kg
Height= 75cm

BSA= Sq. Root [(weight in kg * height in cm) ÷ 3600]

= sq.root [(11.3*75)÷3600]
= sq.root [847.5÷3600]
= sq.root [0.24]
= 0.49
BSA of the child is 0.49 sq meter

Example 3:
A child is to receive dactinomycin 2.5mg/m2 IVP daily for 5days as treatment for Leukemia. The child weighs 48lbs and 4feet 6inches tall. Calculate the dose of dactinomycin to be given each day.

The first step is to calculate the BSA of the child.
Weight= 48lbs
Height= 4ft 6inches (1ft= 12in)
Height= (4*12) + 6= 48+6= 54in

BSA= Sq. Root [(weight in pounds * height in inches) ÷ 3131]

= sq root [(48*54)÷3131]
= sq root [2592÷3131]
= sq root [0.83]
= 0.91
BSA of the child is 0.91 sq meter.

Ordered dose of dactinomycin= 2.5mg per sq meter
Since BSA has been calculated to be 0.91 sq meter
Ordered dose of dactinomycin= 2.5mg*0.91
= 2.28mg

Example 4:
What is the single dose of Phenytoin for a child who is 112cm in length and weighs 25.3kg if the recommended dose is 250mg/m2 divided in 2 doses?
Phenytoin is available as 125mg/5ml. How much would you give for a single dose?

Weight= 25.3kg
Height= 112cm

BSA= Sq. Root [(weight in kg * height in cm) ÷ 3600]

= sq root [(25.3*112)÷3600]
= sq root [2833.6÷3600]
= sq root [0.79]
= 0.89
BSA of the child is 0.89 sq meter

Ordered dose of Phenytoin= 250mg per sq meter in two divided doses (BSA is 0.89 sq meter)
= 250mg*0.89
= 222.5mg in 2 divided doses
Each dose= 222.5mg÷2= 111.25mg

OGUNLABI, David (RN).

CALCULATING FLUID DEFICIT IN A SICK CHILD.

Fluid replacement is very important in children because about 75% of their body weight is made up of water. Fluid loss, especially in children, can be fatal if prompt intervention is not taken to rehydrate the sick child.

Cardinal signs that make children vulnerable to dehydration or fluid loss include: Diarrhoea, vomiting, fever, and some other disease conditions that further increase the metabolic rate in children.

Therefore, fluid and electrolyte therapy constitute a vital component of the care given to a sick child.

Fluid requirements for children are higher than those for adults for the following reasons:

1. Children have higher metabolic rates than adults. High metabolic rate is directly proportional to high caloric demand or expenditure. This translates into high fluid requirement.
2. The surface area to weight ratio is high in children. Increased surface area leads to increase insensible water loss through the skin.
3. Children have higher respiratory rates, and this equates to higher insensible losses from the respiratory tract.

There are two major approaches to calculating fluid deficit in children.
1. The weight of the sick child is known prior illness (pre-illness weight) and compared with the present weight. The difference in weight is used to estimate the fluid deficit.

Example 1:
A 4-year old child was rushed to the emergency department with history of diarrhoea for the past 24hrs. The child’s weight prior illness was 15kg and the present weight is 13kg. Calculate the fluid deficit.

Pre-illness weight= 15kg
Present weight= 13kg
Weight loss= 15kg – 13kg= 2kg
It is assumed that that for every 1kg weight loss, 1 litre of water is lost.

Therefore,
If 1kg weight loss= 1L of fluid loss
2kg weight loss= 2L= 2000ml

Fluid deficit= 2000ml
NOTE: Half (that is, 1000ml) of the fluid deficit is given to the child in the first 8hrs. Then the remaining half (1000ml) is given in the next 16hrs.

2. In this approach, THE PRE-ILLNESS WEIGHT IS UNKNOWN, so the nurse or the physician uses clinical judgement to estimate the percentage deficit of the sick child based on the physical assessment of the child’s present health status. The present weight is also measured.

Fluid deficit= weight (in kg) * %deficit * 10

Volume depletion is categorized into MILD, MODERATE AND SEVERE.

MILD (3-5% volume depletion):
Thirst, decrease in urine output, dry mucous membrane.

MODERATE (6-10% volume depletion):
Postural changes in blood pressure and heart rate, dry mucous membranes, sunken eyes, depressed fontanel, skin tenting, listlessness, tachycardia.

SEVERE (>10% volume depletion):
Poor perfusion, tachycardia, hypotension, lethargy, coma.

Example 2:
A child weighing 23kg presents with a deficit of 6%. Calculate the maintenance fluid and fluid deficit of this child.

MAINTENANCE FLUID.
Using the Holliday-Segar method,
Weight= 23kg (10kg+10kg+3kg)
First 10kg= 10*100= 1000ml per day
Second 10kg= 10*50= 500ml per day
Last 3kg= 3*20= 60ml per day

Maintenance fluid for the 23kg child= 1000+500+60
= 1560ml per day.
NOTE:
One-third of the maintenance fluid is administered in the first 8hrs; the remaining two-third is administered over 16hrs.

One-third of 1560ml= (1*1560) ÷ 3= 520ml over 8hrs
Two-third of 1560ml= (2*1560)÷3= 1040ml over 16hrs

FLUID DEFICIT.
Weight= 23kg
%deficit= 6%
Fluid deficit= weight * %deficit * 10
= 23*6*10
= 1380ml

NOTE:
Half of the fluid deficit is administered in the first 8hrs; the remaining half is administered over 16hrs.

Half of 1380ml= 1380÷2= 690ml over 8hrs
Remaining half= 690ml over 16hrs.

TRY THESE.
Calculate the fluid deficit and maintenance fluid for the following:
1. A child weighing 9kg who is 9% dehydrated.
2. A sick child whose weight prior frequent stooling was 12kg but now weighs 10.5kg.

OGUNLABI, David (RN)