Practical No : 01
Objectives
At the end of the practical, the student should be able to,
1.
Explain how the human body maintains a core temperature at 37 o C i.
Under normal conditions ii.
On exposure to cold environments iii.
With excess heat production.
2.
Measure and record the body temperature accurately using a mercury manometer.
3.
Discuss the advantages and disadvantages of different sites of temperature measurement.
4.
Explain the clinical significance of body temperature measurement.

Man is a homeothermic animal, i.e. he is capable of maintaining a constant body temperature that is independent of the environmental temperature.

A person's body temperature is the balance between heat production and heat loss by his body.

Man's body temperature is maintained in the following range : 97 o
F - 99 o
F

Core Temperature is the temperature of the deep tissues of the body.
This remains constant usually within

1 o F (

0.6
o C).
Core temperature ranges from 98 o
F to 98.6
o
F.
 
Normal Body Temperature
37 o
C (36.3 - 37.1
o
C)
98.4
o
F (97.3 - 98.8
o
F)
Measurement of Temperature:
Equipment : Mercury Manometer or
Thermistor (platinum head in the oesophagus) or
Thermocouple
Sites: Core Temperature -
Surface Temperature -
Rectal, Oesophageal, Nasopharyngeal
Oral, Axillary, Groin
Temperature is most often measured using a clinical thermometer (Mercury
Manometer)
A special thermometer is available for taking the rectal temperature.
Precautions - o When taking oral temperature, hot or cold drinks should not be taken for at least half an hour prior to recording the temperature.

o The subject should not breathe through his mouth when taking the oral temperature. o As it may take upto five minutes for final temperature equilibrium, the thermometer should be kept in place for this amount of time, or till the temperature recorded remains constant.
The thermometer is disinfected with Savlon (the thermometer is kept with its bulb dipped in Savlon solution)
Before using, the bulb is wiped with a cotton swab soaked in sterile water, and shaken until all the mercury within the capillary tube reaches the bulb (the point below the constriction in the tube)
Place the thermometer in the region where temperature is to be measured (mouth, axilla etc.)
Keep the thermometer in place,

Sublingually - approx. 2 min.

Axilla - approx. 3 -5 min.

Groin - approx. 3 -5 min

Rectum - approx. 1 min
After obtaining the reading, wipe the bulb with cotton wool and replace it in the
Savlon solution.
Reading :
Rectal Temperature =
Oral Temperature =
Axillary Temperature =
Advantages & Disadvantages :
Core Temperature
Core Temperature - 1 o
Core Temperature - 2 o
C
C
Axillary Temperature Oral Temperature Rectal Temperature
-
Advantages :
Easy to measure
No discomfort to patient
Useful in small children
Closer to core temperature
Useful in adults and older children
Less discomfort to patient
Easy to measure
Very close to Core
Temperature
Useful in shock states
Disadvantages :
Varies with environmental temperature
Inaccurate in shock states
Children may bite on bulb
Affected by hot or cold drinks
Affected by breathing through the mouth
Aesthetically least acceptable method
Needs patient cooperation
Rigid tube can break in situ

Heat production & Heat loss :
The thermostat is the Hypothalamus
Heat is produced by, Basal Metabolism
Exercise / Emotion
Specific dynamic action of food
Heat is lost via, Radiation, Conduction (70%)
Vapourization of sweat (27%)
Respiratory passages (2%)
Urine and Faeces (1%)
Objectives :
At the end of the practical, the student should be able to,
1.
Identify apparatus and instruments used to inject substances into the body.
2.
Describe the routes of administering injections with examples.
3.
Describe how to do a venepuncture.
Apparatus and Instruments
1.
Hypodermic Syringe
Nozzle
Commonly used in clinical practice for collection of blood for investigations and the administration if drugs.
Maybe glass or plastic
Glass syringes are non – disposable and have to be sterilized
(hot air oven)
Plastic syringes are sterilized chemically and can only be used once. (available with needle).
A syringe has three main parts. The Piston, Barrel, and Nozzle.
Various sizes are available in order to collect varying amounts of blood (1ml – 50 ml)
2.
Needles (Disposable and non-disposable)
Needles are available in disposable and non – disposable
(metal) varieties
Disposable variety is safer as disease transmission can occur from frequently used needles (HIV, Hep.B)
-
Needles have a “Gauge” which corresponds to its internal diameter.
The gauge ranges from 18G (very large thick needles) to 27G
(very fine thin needles). – identified by a colour code
Therefore, the larger the ‘Gauge’, the finer the needle
A needle has two parts, a shank and a beveled edge (reduces pain when puncturing the skin).
Barrel
Piston
Bevelled
Edge
Shank

3.
Intravenous Cannula
Is used mainly to introduce fluids / drugs into the body for over long periods of time.
Ideal for administering fluids continually (fluid therapy).
Can also be used to obtain blood if needed repeatedly.
Consists of a needle, connected to a plastic hub (2way or 3-way), which also has a plastic cap (closing cone), that can be closed when fluids etc. are not being given, as well as a separate injection port. It also has a stylet which helps in introducing the cannula into a vein.
There are two flexible ‘wings’ that are used to anchor the cannula to the skin.
Cannulae are also colour coded according to the gauge.
They are disposable and are available sterilized with
Ethylene Oxide gas. Can be kept in situ for approx. 3 days.
4.
Sterile Lancet
Is used to obtain capillary blood for certain investigations.
They can be obtained in sterilized packs and are disposable.
The lancet has a sharp edge, which is used to prick a subject’s earlobe or finger.
The first drop of blood is generally discarded.
Ideal for blood grouping, PCV measurement etc.
5.
Vacuum Syringes (Vacutainer)
Catheter with steel needle
Flexible wings
Injection port with protective cap
Flashback chamber
Closing cone
Is a type of syringe used in the withdrawal of blood, where blood is drawn under a vacuum.
Is a very safe and painless method.
Especially useful in the collection of blood from patients suspected of having HIV or Hep B infection.
6.
Tourniquet
Is used to compress the blood vessels in a limb.
Often used to obstruct the venous return from a limb to facilitate the withdrawal of blood from a vein (in venepuncture).
May vary in type from simple rubber or plastic tubing to Velcro bands and pneumatic cuffs.

Routes of Administration
There are various routes of administration of substances into the body. The route depends on the site of action and time of action required of a certain drug, substance etc.
Methods,
1.
Intradermal Injection
2.
Subcutaneous Injection
3.
Intramuscular Injection
4.
Intravenous Injection
5.
Intrathecal Injection
Intrademal Injection : Injection is made into the skin
The needle is kept almost parallel to the skin (approx. 15 o )
15 o and then inserted into it.
Prick only approx. 1 mm deep.
A thin needle (25G or 27G) is generally used.
Eg. Manteaux Test
BCG vaccination
Subcutaneous Injection : The substance is injected to the subcutaneous space.
The skin is pinched between the forefinger and thumb, taking care not to pinch any blood vessels.
The needle is then introduced gently.
A short fine needle (25G) is used commonly.
Eg. Insulin administration.
Intramuscular injection : This technique injects substances directly into a muscle.
Common sites are, the Deltoid Muscle and Upper outer quadrant of the buttock.
The needle is introduced at an angle of 90 o to the skin.
Following injection, pressure applied to the area to facilitate
90 o drug dispersion and to avoid formation of a haematoma.
A thicker, longer needle (21 – 22 G) is used as the drugs are generally opaque and thick.
Eg. Vitamins, Antibiotics, Tetanus toxoid
Intravenous Injection : This technique injects substances directly into the vein.
The needle is introduced at an angle of approx. 30 o
- 45 o
(see technique on venepuncture).
Veins in the cubital fossa and dorsum of the hand are used
Eg. Antidotes
45 o
Intrathecal Injection : Employed to inject substances into the subarachnoid space.
Eg. Obtaining CSF for investigation
Anaethetics

Caution
Venepuncture
Indications :
Sites :
Technique :
To obtain venous blood samples for investigation
To transfuse intravenous drugs, fluids or blood
[In order to insert cannulae to distant sites (eg. Heart)]
Antecubital Fossa
Dorsum of the hand and wrist
[Femoral vein / Jugular vein]
Explain the procedure, obtain consent and reassure the patient
Wash hands thoroughly and wear gloves
Determine a suitable, preferably visible vein.
A tourniquet is applied proximally to the chosen site.
The vein is then made prominent by lightly tapping on it and asking the patient to clench and unclench the fist of that arm.
Clean the area with surgical spirit
Insert the needle at an angle of 30 – 45 o
and feel for the loss of resistance when the vein is entered into.
This will be indicated by a flash of blood into the hub of the needle.
(In the case of injecting drugs, we should carefully observe the flash of blood into the hub of the needle, and only then, inject the substance into the vein.)
Withdraw blood slowly into the syringe taking care not to create bubbles.
Remove the tourniquet and slowly withdraw the needle.
Apply a cotton swab to the area and elevate the arm or apply pressure to prevent extravasation of blood into the surrounding tissues.
Next, cap the needle and remove it from the syringe.
Put the blood into a suitable bottle to send for investigation.
: Care should be taken to avoid spillage of possibly infected / contaminated blood onto skin or any other surface

Objectives :
At the end of the practical, the student should be able to,
1.
Identify the methods of sterilization and disinfection
2.
List the practical applications of sterilization and disinfection in a hospital setup.
Sterilization -
Is the destruction of the vegetative forms as well as spores of bacteria, viruses and fungi.
Disinfection -
Is the destruction of only the vegetative forms of organisms. The spores remain intact.
Physical Methods Chemical Methods Filtration
Heat
Dry heat
Radiation
Gases Liquid
Micropore and
Millipore filters
Moist heat
Red Heat
Inoculating wires
Points of forceps etc.
Hot air oven
At 160 o
C for 1 hour
Used for heat resistant glassware and metal instruments
Ethylene Oxide
Eg. Disposable syringes
Use of ultraviolet rays.
For ionizing radiation, x-rays and

rays are used.
Eg.
Heat unstable instruments
Prepacked disposable items
Plastic syringes
Infra red radiation
Scissors
Catheters
Rubber equipment
Instruments that cannot withstand dry heat are sterilized by this method.
2% Gluteraldehyde eg. Endoscopes
Eg. Glassware, Syringes
At temperatures <100 o
C At temperatures of 100 o C
Pasteurization of milk
Bed linen sterilization
Clothes
Steaming
Boiling
At temperatures > 100 o C
Done by steaming under pressure (autoclave)
121 o
C for 15 min. or
134 o C for 3 min.
Gloves eg. Surgical instruments
Dressings

Halogens - Used in treatment of water supplies
Cleaning walls, countertops and furniture
As skin disingectants (povidone iodine)
Eg. Tincture of Iodine 2.5%I
2
or 2.5% KI in 90% alcohol
Methylated spirits - Used as skin disinfectants
Eg. 70% Alcohol
Phenolic Derivatives - Eg. Hibitane
Chlorhexidine
Lysol
Quaternary Ammonium Compounds
Used as a pre-operative skin disinfectant in combinatoion with other disinfectants.
Not very effective alone
Eg. Cetrimide
Soaps and Detergents
Oxidising Agents - H
2
O
2
KMnO
4