Test Lab 13 Introduction A sweat test measures the amount of salt chemicals sodium and chloride in sweat to diagnose cystic fibrosis Sodium and chloride are part of your bodys electrolyte balance and combine to form the salt found in ID: 562474
Download Presentation The PPT/PDF document "Sweat" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Sweat Test
Lab 13Slide2
Introduction A sweat test measures the amount of salt chemicals (sodium and chloride) in sweat to diagnose cystic fibrosis
Sodium and chloride are part of your body’s electrolyte balance, and combine to form the salt found in
sweat.
They
help
regulate the fluid
balance in your
tissues.
Normally
, sweat on the skin surface contains very little sodium and chloride. People with cystic fibrosis (CF) have 2 to 5 times the normal amount of sodium and chloride in their sweat.Slide3
Cystic fibrosis Cystic fibrosis (CF), mucoviscoidosis, or mucoviscidosis of pancreas,
is a life - threatening hereditary disease
inherited
as autosomal recessive and is characterized by:
Increased
viscosity of mucous secretions
, including
pancreas
, intestinal glands, tracheal, peritracheal,
bronchial.
Thick
mucus production, as well as a less competent immune system, cause mucus to
build up and clog
some of the organs in the body, particularly in the lungs and
pancreas. When
mucus clogs the
lungs, it makes
breathing very difficult. Slide4Slide5
It also causes bacteria (or germs) to stuck in the airways causing inflammation (or swelling) and infections which ultimately leads to lung damage.
Mucus also can block the digestive tract and pancreas causing
stop of
digestive enzymes
from getting to the intestines
.
Increased
concentration of electrolytes especially Na and CL
, in secretion of other gland notably (sweat glands, Parotid salivary glands, lachrymal glands
).Slide6Slide7
Symptoms of cystic fibrosis (CF)Thick, viscous mucus secretions in the lungs Repeated infections.
Pale or clay colored Stools,
foul smelling, or
stools that float
meconium
ileus
is a typical finding in newborn babies with CF
Recurrent
pneumonia
Chronic cough, possibly with blood streaking
Wheezing
BronchitisSlide8
Chronic sinusitis Asthma Weight loss, failure to thrive in infants, abdominal swelling Excessive salt in sweat, dehydration Failure of newborn to pass stool Abdominal pain, flatulence
Fatigue Changes in color and amount of sputum (material coughed
up from the lungs) Slide9Slide10Slide11
Sweat AnalysisSlide12
Two methods of sweat analysis are most frequently used:1. Chloride concentration The sweat chloride analysis is recommended as the diagnostic test for CF. 2. Conductivity measurement
.
Sweat
conductivity may be used to screen for CF.Slide13
Sample collection
Earlier
methods:
to
stimulate the production of sweat including the use of
humid high temperature room
, and encasing the
patient’s
Body in plastic. Slide14
Current methods1. A tiny amount of a sweat-stimulating liquid is applied to a small patch of skin on the arm or leg.
2. An electrode is then placed over the site & a weak electrical current stimulates the area.
This is a painless procedure that may create a tingling or warm sensation
.
3. After several minutes, the area is cleaned and sweat is collected for about thirty minutes, either into a plastic coil of tubing or onto a piece of gauze or filter paper.
4. The sweat obtained is then analyzed.Slide15
Procedure of the test
Done
on a baby's right arm or thigh
.
With
older child or adult, the test is usually done on the inside
of the
right
forearm.
Sweat
may be collected and
analyzed
from
two different
sites
.Slide16
Skin is washed and dried & then, 2 small gauze pads are placed the skin.One pad is soaked with a medicine called pilocarpine makes skin sweat.The other pad is soaked with salt water such as NaNO3
.The other pads called electrodes are placed over the gauze pads.
The
electrodes are hooked up to an instrument that produces a mild electric current, which pushes the medicine into the skin.
Another testing method collects the sweat into a coil (
macroduct
technique). Slide17
The sweat test usually takes 45 minutes to 1 hour.Slide18
After 5 to 10 minutes, the gauze pads and electrodes are removed, then the skin is cleaned with water and then dried. The skin will look red in the area under the medicine-containing padA dry gauze pad, paper collection pad, or special tubing is taped to the red patch of skin. This pad is covered with plastic or wax to prevent fluid loss (evaporation). Slide19
The new pad will soak up the sweat for up to 30 minutes, then it is removed and placed in a sealed bottle. It is then weighed to measure how much sweat the skin produced, and it is checked to find out how much salt chemical (sodium and/or chloride) the sweat contains. After the collection pad is removed, the skin is washed and dried again. Then we measure Cl by automated or manual titration method and Na by flame photometry or ion exchange electrode.Slide20
A sweat test measures the amount of salt chemicals (sodium and chloride) in sweat. Generally, chloride (sweat chloride) is measured.Sweat chloride Normal Less than 40
(mmol/L)
Borderline
40–60
mmol
/L.
Abnormal
More than 60
mmol
/L.
Abnormal
(high) values
: Usually mean a person has cystic fibrosis. Some people with cystic fibrosis have borderline or even normal sweat chloride
levelsSlide21
Thank you