OBSTETRICAL INSTRUMENTS AND EQUIPMENTS

 

OBSTETRICAL INSTRUMENTS AND EQUIPMENT

An ideal obstetrical instrument should be simple in design and lucid. It should be dealing with all abnormal conditions to be encountered in practice and can be used by a less experienced person without danger of injury to the mother. The best way to handle an obstetrical case is by applying the correct obstetrical instrument which is available, with the correct knowledge and experience. The instrument should be kept clean and sterile. If possible the obstetrical instrument should be covered with a sterile drape during the operation.

  LIST OF OBSTETRICAL EQUIPMENT -:

Ø Cotton wool.

Ø Sterile gauge.

Ø Rubber sheets.

Ø Local anesthetics.

Ø Obstetrical lubricants.

Ø Soap and clean hot water.

Ø Suture materials with needles.

Ø Intravenous infusion apparatus.

Ø Hypodermic needle and syringes.

Ø Surgical spirit/Antiseptic solution.

Ø Protective clothing ( Coverall, Rubber boots, Gloves ).

Ø Drugs like Oxytocin, Calcium borgluconate, and styptics.

  OBSTETRICAL INSTRUMENTS: Names and uses of obstetrical instruments according to use are as follows:

Commonly used instruments :

a) Vaginal speculum: Used for examination of the vaginal mucus membrane and the os externus for the presence of any abnormal discharge, pus, trauma, laceration, adhesion, growth, and other congenital defects, etc. in the birth canal and also for insemination or medication in small animals.

b) Cervical dilator: Used for dilation of the cervix, which is partially dilated cases at the time of parturition.                 

c) Uterine dilator:  Used for the dilation of the uterine lumen in a difficult birth.      

Instruments for traction:

a)  Snares: They are made of thin, nylon-coated, twisted cable/wire with a long handle. This is equipped with a locking device that will not tighten down on the body part to which it is attached. This is very useful in pulling the head into proper alignment and securing the lower jaw or limb with fewer chances of slipping off.  It does not cause injury to the teeth and hoof.

b)  Snares introducer: A curved handle ends in a weighted bulb in which the wire is threaded. Used for introducing snare around the different parts of the fetus at the time of handling the dystocia. Obstetrical snare with snare introducer used for applying traction.

c)  Fetal extractor/Calf puller: These are the mechanical hoisting or jacking device and have proven very useful to allow the traction applied upwards, downwards, or either side during dystocia to pull the calf. Vink calving jack and HK calf puller are to be used as traction instruments.

d)  Obstetrical chains with handles: This is an alternative to snares. The chains are strong, easy to apply, and do not cause injury to the fetus and genital tract of the dam. They are made of stainless steel and can be easily sterilized and therefore excellent to use on decomposed fetuses. The Moore’s obstetrical chains, Muir’s chain handle, and Gibbon's chain handle are the instruments used for traction.

e)  Forceps: Wide varieties of forceps are used to handle the cases of dystocia in sheep, goats, swine, dogs, and cats.  The anterior portion is semi-curved, rounded, and smooth which avoids injury to the fetal tissue or genital tract of the dam. It is used for delivering the fetus at parturition in the above animals, usually, the head of the fetus is withdrawn by forceps.

  f)  Hooks :

     i. Long Hooks ( Sharp or Blunt ): 

          The long hooks have a handle at the end opposite to the hook. In general, long hooks are easy to apply because they can be turned or pushed from outside the vulva.

   ii. Short Hooks (Sharp or Blunt ):

   Short hooks have an eye at the base through which a cord is run to apply force for traction. The long hooks have a handle at the end opposite the hook. 

·      Sharp hook: Sharp hooks are used in cases of dead fetuses only.

 

Blunt hook: Blunt hooks are used in live as well as dead fetuses.  The blunt hooks do not cause injury to fetal tissue or the genital tract of the dam.

 Instruments for repulsion (retropulsion) and rotation:

 

A     For Repulsion :

 

a)   Kuhn’s crutch: It is used for repelling the fetus during manipulative correction of dystocia. It is usually applied in the brisket region of the fetus in anterior presentation and around the perianal region in posterior presentation.

b)   William’s crutch or repeller: It is useful when a fetus is firmly impacted in the pelvic inlet. By using a crutch the fetus can be repelled downward and forward, upward and forward, or laterally forward.

A      For Rotation :

 

a) The fetal rotator: It is used to rotate the fetus when it is in longitudinal presentation and in an abnormal position. 

b)  Detorsion rods: Cornell’s detorsion rod or Cammerer’s torsion fork can also be used for repulsion and detorsion of the fetus.

  Instruments for section/ foetotomy:

 

a)  Wire saws: It is the wire used to saw the fetus, hence, also named as wire saw. Approximately 10 feet of wire is used at one time for the amputation of the fetal part. They are usually cut only in one direction.

b)  Chisels: Guard’s chisel and William’s chisel are used for the various fetal parts. The usefulness of chisels is limited. 

c)  Spatula: It is used in subcutaneous foetotomy.

d)   Fetotomes:  These instruments are used in foetotomy operations to reduce the size of the fetus. A threader or guide is used to place the wire through the foetotome. These have the advantage over the chain, saw and wire saw. Various types of handles are available for fetotome wire. eg - Thygesen’s foetotome, is in two separable pieces with two barrels for the wire saw. The two parts can be separated, cleaned, and boiled easily in the sterilizer. 

e)  Knife: A heavy sharp knife made up of stainless steel and is used for intra-uterine embryotomy operation can be used in cutting the portion of a fetus that may be outside the vulva. Gunther’s finger knife, Unsworth’s knife, Robert’s fetotomy knife, and Hoeblade castrating knife is easy to guard with the hand while in the uterus.

f)  Guarded embyotome: These are used to make incisions on the fetus within the uterus to drain fluid or gas for the reduction in size and easy delivery in ascitic, anasarca, or emphysematous fetuses. 

PRECAUTIONS DURING USE OF OBSTETRICAL INSTRUMENTS :

Ø Use good quality, stainless steel/ chrome plated and sterilized instruments.

Ø Store the instruments in a safe place/instrument cabinet after cleaning, drying, and sterilization.

Ø       Ø If possible the obstetrical instrument should be covered with a sterile drape during the operation.

Ø Proper restraining the animal is of the utmost importance.