TABLE
Lubricant use and cytology findings
| Total no. | Water lubricant, % (n) | Gel lubricant, % (n) | No lubricant, % (n) | |
|---|---|---|---|---|
| Lubricant use reported | 615 | 62 (379) | 13 (81) | 25 (155) |
| Adequate sample | 611 | 99.2 (376) | 98.8 (80) | 100 (155) |
| Inadequate sample | 4 | 0.08 (3) | 1 (1) | 0 (0) |
| Not obscured | 588 | 96.8 (367) | 93.8 (76) | 93.5 (145) |
| Obscured | 27 | 3 (12) | 6.2 (5) | 6.5 (10) |
| By blood | 16 | 58 (7) | 20 (1) | 80 (8) |
| By other* | 11 | 42 (5) | 80 (4) | 20 (2) |
| *Defined as obscuration by nonblood contaminant(s). | ||||
Discussion
The purpose of this study was to identify any differences in the occurrence of contamination or distortion of cervical cytology test results between water and gel as the lubricant. With a sample size that allowed us to detect an absolute difference as small as 7%, we found no significant difference between the use of gel or water lubricant in the likelihood of cell obscuration or inadequacy. These findings did not support current data reported in several publications and may explain the lack of publications describing specific adverse gel effects on sampling collection.
Inadequate specimens in postmenopausal women
The number of obscured and inadequate specimens found within the group of women who had reached menopause was not unexpected because of hormonal changes in cervical cells and the physical structure of the uterus. Although not unexpected, it is of concern that this group includes many older women who constitute an underscreened subgroup who frequently forego routine cervical cancer screening unless they have gynecologic problems.4
In recognizing the need for this group to obtain testing and maintain routine screening compliance, minimizing discomfort related to cervical cell acquisition procedure should be a primary consideration. Because lubricant minimizes friction and optimizes the ease of speculum insertion, gel can be considered an effective choice for these women.
Sampling errors
Nationally, approximately two thirds of false-negative smears are related to inadequate sampling, and the primary sampling error is the failure to obtain cells from the transformational zone, where cancer is known to develop.5,6 The high percentage of specimen adequacy (99% for the water and gel groups and 100% for the no-lubricant group) found during this study may be attributed to the homogeneity in clinical training of the participating residents.
Although different labs evaluated cytology specimens (depending on the payment source), all providers who performed cervical cell acquisition were considered influenced by similar training. Also, all of our residents are taught that when gel lubricant is used, a thin coat is to be placed only on the external speculum blade surfaces.
Limitations of this study
The size of the study population was limited by medical record completeness and the response rate for physician surveys. A larger study might have found a difference, although it is questionable whether such a difference would be statistically significant.
Reliance on a survey of the usual type of lubricant may be less accurate than direct observation; however, direct observation was not practical in our setting. The adequacy and quality of cytology specimens also could have been affected by cervicitis, vaginitis, interval from last menstrual period, and use of hormone therapy, but these conditions would not be expected to affect the patients of physicians using one type of lubricant more than those using another.
In addition, we were limited in designing the study by the lack of comparison literature. As with other studies of this size, further research is recommended, with additional clinicians and study populations to reinforce and elaborate on the current findings.
Conclusions
A thin coat of water-soluble gel on the external vaginal speculum blade surfaces did not compromise the adequacy or interpretation of cervical cytology. Gel should be considered an option in obtaining Pap smears to ease insertion, minimize discomfort, and perhaps help maintain regular interval sampling compliance. Physicians choosing to use gel should be careful to apply only a thin layer to the outer blades of the speculum.
Corresponding author
Pamela D. Connor, PhD, 66 N. Pauline, Memphis, TN 38163. E-mail: dconnor@utmem.edu.