RUBIN’S TEST (RT)

RUBIN’S TEST (RT)

It is tubal insufflations test which was introduced by Rubin 1920. It is not done now because other better diagnostic facilities are available.

Time

From 6^th to 10^th day of menstrual cycle ie soon after the period is over. At this time there is no risk of gas embolism or of disturbing the fertilized ovum.

Instruments

·       Rubin’s insufflaton cannula

·       Vaginal instruments

·       Kymographic apparatus or simple air insufflators

Procedure

ü  Outpatient procedure

ü  No anesthesia as normally no cervical dilatation is required

ü  Injection atropine, 0.6mg, half an hour before the procedure

ü  Emptying of bladder

ü  Lithotomy position, aseptic and antiseptic precautions

ü  Per vaginal examination

ü  Expose the cervix, catch its anterior lip by tinaculam

ü  Cannula is fitted to simple air insufflators or kymorphic apparatus (CO₂) gas is used.

Instrument is checked for patency as well as for abnormal leakage.

ü  Then introduce the cannula gently through the cervical canal

ü  In rubin’s cannula acorn (rubber color) is firmly pressed against external os and its tip lies beyond the internal os.

ü  Cervix is pulled by tinaculam for air tight fitting

ü  Rate of carbondioxide flow is 10-30cc/min. It should not exceed 60cc/minute. Total gas is usually sufficient, for single test.

Contraindications

1.     Local or pelvic infections

2.     Suspected pregnancy

3.     Uterine bleeding

4.     Recent curettage

5.     Heart or lung diseases

Complications

1)     Spreading or activating pelvic infection

2)     Collapse and vomiting

3)     Embolism

4)     Rupture of uterus or tubes

5)     Regurgitation

6)     Endometriosis.

Rubin’s test positive: patent tubes (atleast one is patent)

Rubin’s test negative: blocked tubes

Criteria for positive RT:

1.     Hissing, gurgling or bubbling sound heard on auscultation of the lower abdomen

2.     Post procedure pain in right shoulder and neck when the patient sits up

3.     X-rays abdomen in standing position after procedure shows gas under diaphragm

4.     Typical kymorphic tracing

False positive: 3-4% even when both tubes are blockes. Reasons include large hydrosalphinx, intravasation, leak in the apparatus, perforation of the uterus.

False negative: ie failure to pass gas in the peritoneal cavity even when the tubes are patent. 33% cases at first sitting. Reasons include tubal spasm, block in the instrument, functional closure at uterine end due to edema and hypertrophy of endometrium particularly in premenustral phase.

·       Besides its diagnostic value it has therapeutic effect in 20% cases, due to temporary clearance of secretions from the tubes.

·       A positive test ordinarly means that at least on tube is open but it does not exclude the presence of significant tubal damage and periorbital adhesions. In case of negative test it does not give the site of block.