Pain, Nerve, Pregnancy, Abdominal, Termination of Pregnancy
Conditions
Keywords
TENS, pain relief, STOP, surgical abortion
Brief summary
To study the effectiveness of the pain relief method of transcutaneous electrical nerve stimulation (TENS) for women who will undergo suction evacuation under conscious sedation for first trimester termination of pregnancy.
Detailed description
Suction evacuation is a minor gynecological procedure commonly performed at an outpatient setting for termination of pregnancy. Although it is a simple surgical procedure lasting 5-10 min and can be done under various methods of pain control, 78-97% of women still report at least moderate procedural pain, especially during injection of paracervical block, cervical dilation, suction aspiration and postoperatively with uterine cramping. In addition, those pharmacological analgesic methods are often associated with numerous adverse effects and cannot be applicable to all women. The transcutaneous nerve stimulation (TENS) method is commonly used to treat labour pain. It is an inexpensive, quick, easy to use and noninvasive pain relief method. A recent study by Lison et al. on TENS for office hysteroscopy demonstrated a significant decrease in pain scores when compared to control and placebo groups. The rationale of TENS lies in achieving pain reduction when electric stimulation alters the nociceptive transmission in the dorsal horn of the spinal cord; this means the electrode has to be adequately applied in the right receptive field of the body to achieve pain control. For the setting of TENS there is evidence supporting superior pain relief by random high frequencies TENS over fixed frequency. Increasing the pulse duration to above 250 microseconds also produces better analgesics effect. In suction evacuation, the nerve roots of T10-L1 and S2-S4 becomes relevant as they correspond to the nerve supply to the whole uterus and cervix. Lison et al placed electrodes at these levels parallel to the spinal cord in their study and have instructed their subjects to increase the TENS intensity to the maximum nonpainful level, allowing further increase when their stimulus perception decrease as a result of nerve accommodation. Its use in suction evacuation however, remains undetermined as there is no published study in this area.
Interventions
The active TENS unit (delivers electrical stimulation) with indicator light
DEVICEPlacebo Transcutaneous nerve stimulation (TENS)
the placebo TENS unit (delivers no electrical stimulation) with indicator light
Sponsors
Queen Mary Hospital, Hong Kong
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Masking description
After the written informed consent is obtained, subjects will be randomly allocated into one of the two groups: (a) the active TENS group and (b) the placebo TENS group.
Eligibility
Sex/Gender
FEMALE
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Chinese aged 18 years or above and mentally competent * Up to 12 weeks gestation on the day of STOP * Size of the uterus on pelvic examination compatible with estimated duration of pregnancy, or dating confirmed with ultrasound scan * Normal general and gynecological examination
Exclusion criteria
* Skin damage or allergy at site of TENS pads application * Previous experience with TENS * History of pacemarker insertion * History of severe respiratory or cardiac disease * Severe and recurrent liver disease * Allergic to lignocaine * Myasthenia gravis * Psychiatric conditions requiring medication * Disorders that constitute contraindications to use of prostaglandins
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| To assess the change of 100-point visual analogue pain scale in 3 time points | Patient will be asked for the pain intensity by using the 100 mm linear VAS 5 minutes before receiving the active TENS/ placebo TENS before the start of suction evacuation, reassess 20 minutes later and 1 hour after operation. | To measure patient's pain intensity before and after suction TOP by using The Visual Analogue Scale (VAS) consists of a straight line length of 100 mm with the endpoints defining extreme limits such as 'no pain at all' and 'pain as bad as it could be'. The patient is asked to mark his pain level on the line between the two endpoints. The distance between 'no pain at all' and the mark then defines the subject's pain. This tool was first used in psychology by Freyd in 1923. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| To assess the change of Anxiety level of the patients in 3 time points by using State-Trait Anxiety Inventory Questionnaire to record patient's anxiety level. | Patient will be asked for the anxiety level by using STAI 5 minutes before receiving the active TENS/ placebo TENS before the start of suction evacuation, reassess 20 minutes later and 1 hour after operation. | To record patient's anxiety level for comparison |
| To assess the difficulty of the operation | The surgeon will be asked to fill the assessment form right after the suction evacuation operation immediately. | The surgeon will assess the difficulty of the operation by using LEVEL OF SEDATION AND DIFFICULTY OF OPERATION ASSESSMENT FORM (proposed by Ramsay et al.) |
Countries
Hong Kong
Outcome results
None listed