CONTRACTION STRESS TEST, OBSTETRICAL INVESTIGATION

1. CONTRACTION
STRESS TEST

2. DEFINITION
• A TEST IN WHICH THE FETUS IS
EXPOSED TO THE STRESS OF UTERINE
CONTRACTIONS TO DETERMINE
WHETHER THERE IS ADEQUATE
PLACENTAL PERFUSION UNDER
SIMULATED LABOR CONDITIONS.

3. METHODS
1. OXYTOCIN CHALLENGE TEST
2. BREAST STIMULATION

4. OXYTOCIN CHALLENGE TEST

5. PURPOSE
TO ASSESS THE FETAL ABILITY TO
COPE WITH THE CONTINUATION
OF A HIGH RISK PREGNANCY.
TO DETERMINE THE PROJECTED
ABILITY OF THE FETUS TO
WITHSTAND THE STRESS OF
LABOR.

6. INDICATIONS
IUGR
POSTMATURITY.
HYPERTENSIVE DISORDER OF
PREGNANCY.
DIABETES MELLITUS.
WOMEN WITH NON REACTIVE NST.

7. CONTRAINDICATIONS
• THIRD TRIMESTER BLEEDING.
• INCOMPETENT CERVIX.
• MULTIPLE GESTATION.
• PREVIOUS CLASSICAL UTERINE
INCISION.
• HYDRAMNIOS.
• HISTORY OF PRETERM LABOR.
• PREMATURE RUPTURE OF
MEMBRANE.

8. ARTICLES
FETAL MONITOR,MONITOR
STRIP,TRANSDUCER AND MONITOR
BELT.
• IV LINE TO ADMINISTER A DILUTE
DOSE OF OXYTOCIN.
• AN IV INFUSION PUMP TO MONITOR
THE FLOW RATE.
• INJECTION OXYTOCIN AND IV
FLUIDS.

9. PROCEDURE
• EXPLAIN TO MOTHER THE PROCEDURE
AND ITS PURPOSE.
• MAKE SURE THAT THE WOMAN HAD
EATEN FOOD AND ASK HER TO EMPTY
HER URINARY BLADDER.
• TURN ON THE MONITOR AND PRESS
“TEST” BUTTON TO SEE THAT IS
WORKING AND ADJUST THE PAPER
SPEED(3CM PER MIN).

10. CONT…..
• PERFORM AN ABDOMINAL PALPATION.
• POSITION THE WOMAN IN SEMI-
FOWLERS OR LATERAL TILT POSITION
AND PLACE THE MONITOR BELTS
UNDER HER BACK SO THAT THEY ARE
FLAT AGAINST HER SKIN.
• CONNECT THE ULTRATRANDUCER AND
TOCOTRANSDUCER TO FETAL MONITOR.

11. CONT…..
• PLACE THE ULTRASOUND
TRANSDUCER ON THE MATERNAL
ABDOMEN OVER THE FETAL BACK.
• MOVE THE TRANSDUCER UNTIL THE
CLEAR AND AUDIBLE FETAL HEART
TONES ARE HEARD. SECURE THE
DEVICE IN PLACE WITH BELT.
• PLACE TOCO TRANSDUCER ON
FUNDUS AND SECURE WITH BELT.

12. CONT…
• RUN THE MONITOR AND EVALUATE THE
QUALITY OF TRACING TO DETERMINE
IF IT IS ADEQUATE FOR
INTERPRETATION.
• START THE OXYTOCIN INFUSION AT
THE RATE OF 1mu/ MIN.
• STEP UP THE OXYTOCIN INFUSION
RATE AT EVERY 15 MINUTES AT THE
PRESCRIBED RATE UNTIL THE UTERINE
CONTRACTIONS ARE ESTABLISHED.

13. CONT…
• MONITOR THE UTERINE CONTRACTION
USING HANDS.
• CONTINUE THE INFUSION UNTIL THE
CONTRACTIONS ARE OCCURING AT A
FREQUENCY OF AT LEAST ONE IN A 10
MINUTE PERIOD AND LASTING AT
LEAST 30 SECONDS.
• RECORDE STRIP TAKEN OUT AND
OXYTOCIN INFUSION DISCONTINUED.

14. INTERPRETATION
• NEGATIVE:
No late decelerations present throughout
the test. Indicates fetal well-being and
predicts that the fetus will continue to be
alright for another week without
intervention of delivery.

15. Cont....
• POSITIVE:
repeated late decelerations of fetal
heart patterns occur during the test.
HYPERSTIMULATION:
contractions are more frequent than
two per minutes or for duration of more
than 90 sec. The test should be stopped
and repeated within 24-48 hours.

16. Cont....
• SUSPICIOUS:
Occasional late decelerations with
continued contractions. The CST should
be repeated within 24-48 hours.
UNSATISFACTORY:
The recording is not of good quality to
be interpreted. This may be due to
problems inherent with monitoring.

17. SPECIAL CONSIDERATIONS
• DISCONTINUE INFUSION WHEN:
1. Criteria are met.
2. Hyper stimulation occur.
3. Prolonged deceleration / bradycardia
occur.

18. THANK YOU