Showing posts with label Pediatrics. Show all posts
Showing posts with label Pediatrics. Show all posts

Tuesday, May 15, 2012


Determining the size of the endotracheal tube

We must select the largest diameter ETT that can be tolerated for adults. 
A size 7.5-mm cuffed ETT is well tolerated by most adult female patients. 
A size 8.0-mm cuffed ETT is well tolerated by most adult male patients.

An uncuffed ETT should be used for children under the age of 8 years.  

The formula most commonly used is:
ETT size(mm) = (Age[yr] +16)/4

To estimate the depth of insertion for a child older than 2 years:
Depth of insertion = 3× internal diameter of the ETT

Friday, January 27, 2012


Retropharyngeal abscess - X-ray

Retropharyngeal abscess is a rare condition presenting in infants (<1 year of age). Clinical symptoms include fever and drooling. 
As a result of the swelling within the posterior pharyngeal wall causing upper airway obstruction, the child
will typically hold their neck in extension to assist breathing. 
A lateral soft tissue neck radiograph taken with the neck held in extension is indicated if a retropharyngeal
abscess is suspected. If it is positive, it will demonstrate air within the swollen retropharyngeal tissues, as shown by the x-ray above. A contrast enhanced computerized tomography (CT) examination will confirm the diagnosis.

Sunday, January 1, 2012

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Chickenpox - dew on rose petal appearance

Chickenpox is a benign viral disease of childhood, characterized by an exanthematous vesicular rash. It is an extremely common and contagious condition. It is caused by the varicella-zoster virus which is a herpes virus and contains a double stranded DNA in its center.

Age group affected- 5 to 9 years. The infection can be there at other ages too but it is less frequent.
It is highly contagious and it affects all races and both sexes equally. The attack rate is around 90% among seronegative persons.

Incubation period- 10 to 21 days but is usually 14 to 17 days.
Patients are infectious around 48 hours from onset of vesicular rash, during the period of vesicular formation (around 4-5 days) and until all vesicles are crusted.

Transmission occurs by respiratory route. The virus is believed to be localized in the nasopharynx, in the reticulo-endothelial system. It then enters the blood. This stage of viremia is characterized by diffused skin lesions. There is the formation of vesicles that are initially clear but later become cloudy due to accumulation of polymorphonuclear leucocytes and degenerated cells along with fibrin. In the end, these vesicles either rupture or get absorbed.

Clinical features:
Most patient present with rashes, low-grade fever and malaise. This lasts for around 3-5 days. The skin lesions are characteristic for this disease. There are maculopapules, vesicles and scabs in various stages of evolution. This is shown in the figure below.

There is shifting from maculopapules to vesicles over hours to days. Usually the trunk and face is affected and this shifts to other regions of the body. The base of these vesicles are erythematous and they appear in crops i.e. some are still developing while others are healing. The classical sequence is macules, papules, clear vesicles, pustules, central umbilication and eventually crust formation. The classical  description of the lesion is a 'dew drop on rose petal' appearance. The rose petal refers to the reddish irregular papule and the clear vesicle on it is the dew drop.

1) The most common complication is secondary superinfection of the skin lesions with bacteria.
2) The CNS can be involved at times leading to acute cerebellar ataxia, aseptic meningitis, encephalitis, transverse myelitis or even Guillain-Barre syndrome.
3) Varicella pneumonia is the most dreaded complication.

1) Good hygiene - daily bathing, nail cutting.
2) Tepid water baths, wet compresses and anti-pruritic drugs for itching.
3) Acyclovir 800 mg 5 times per day or valacyclovir 1 g TDS for 5-7 days for adolescents. The dosage of acyclovir for younger patients is 20 mg/Kg 6 hourly.

The disease can also be prevented by vaccination. A live attenuated varicella vaccine (Oka strain) should be given at the age 12-15 months and then repeated at 4-6 years.

Tuesday, October 4, 2011


Grading of murmur

The intensity of a systolic murmur is not always proportional to the hemodynamic disturbance. Yet murmurs are classified according to the loudness.
Freeman and Levine were the first to introduce a numerical scale for grading heart murmur intensity in 1933. This grading is still used but with some modifications.

Grade 1 - so faint that it can be heard only with special effort.
Grade 2 - faint but can be heard easily.
Grade 3 - moderately loud but no thrill.
Grade 4 - very loud and thrill may be there.
Grade 5 - extremely loud and can be heard if only the edge of stethoscope is in contact with skin.
Grade 6 - exceptionally loud and can be heard with stethoscope just removed from skin contact.

Keren, Tereschuk and Luan suggested that we can use heart sounds as an internal reference to differentiate between grades 1-3, the only limitation of the study being a small sample used. The grading is the same as above but. . .

Grade 1 - clearly softer than the heart sounds.
Grade 2 - approximately equal in intensity to the heart sounds.
Grade 3 - clearly louder than the heart sounds.

Sunday, August 7, 2011

Macewen's sign / cracked pot sound

The sign was described by Sir William Macewen.
The test is performed by percussing on the skull of the patient and a cracked pot sound can be heard to the naked ears of the examiner brought closed to the skull.
This sound can be heard even better if percussion is done on one side while a stethoscope is placed on the other side.

A positive test is indicative of separated sutures. As long as the anterior fontanel is open i.e. up to 18 months, the test will be positive.
In pathological cases, it is due to a raised intracranial  tension due to hydrocephalus or an abscess.

Tuesday, March 15, 2011

Body surface area mesurement

Various formulas exist to estimate the body surface area, the simplest one being that published by Mosteller in the NEJM in 1987. The formula goes like this. . .

The reference value for an adult is considered to be 1.73 m².
A proteinuria of at least 3.5 g/ day/1.73 m² BSA is considered diagnostic for nephrotic syndrome. 

Tuesday, May 4, 2010

Apgar scoring - table, mnemonic


The Apgar score was devised in 1952 by Dr Virginia Apgar (anesthesiologist) as a simple and repeatable method to quickly and summarily assess the health of newborn children immediately after birth. 

This helps to identify those requiring resuscitation and can also be used to predict survival in the neonatal period. 

apgar chart

A mnemonic for learning purposes includes:

A - Appearance (skin colour)
P - Pulse (heart rate)
G - Grimace (reflex irritability)
A - Activity (muscle tone)
R - Respiration 

apgar mnemonic

Another mnemonic is also useful: 

How -   Heart rate
Ready - Respiration
Is -        Irritability
This -    Tone
Child -   Colour

apgar test chart
Apgar scoring is divided into 1 and 5-min scores.

Sixty seconds after complete birth, the five parameters specified in the table above must be evaluated and scored. A total score of 10 indicates that the baby is in the best possible condition. A score between 0-3 means that immediate resuscitation must be done. The score was not designed to predict neurological outcomes. It is normal in most patients who subsequently go on to develop cerebral palsy.

The score at 5 minutes associated with a low pH is a better indicator of neonatal mortality. Umbilical artery pH less than 7 and a 5-min score of 0-3 increases the relative risk of mortality in both pre-term and term babies.

First published on : 4 May 2010
Last reviewed on : 2 May 2020