| Methods |
Randomized double‐blind placebo‐controlled trial. Computer generated block randomization sequence (block size 20), through an inverstigator not involved with recruitement. Study syringes were identically looking and prepared by the study nurse and coordinator who labeled them with consecutive numbers. Subjects were also enrolled with consecutive numbers. The Investigator was blinded.
Per power analysis 40 women needed per study group.
Planned Parenthood at Columbia Willamette in Portland, Oregon, USA. Study length: November 2003 to December 2004. |
| Participants |
80 pregnant women. Age: 18 years old or older (mean 26). Good general health. English speaking. Gestational age: Less than 11 weeks by LMP confirmed by ultrasound. Body weight more thn 100lbs (approx 45kg) |
| Interventions |
Group 1: intrauterine infusion of 5ml of 4% lidocaine (maximum total lidocaine dose of 300mg).
Group 2: intrauterine infusion of 5ml of sterile saline.
All participants: premedication with 800mg ibuprofen and if requested 5mg diazepam (per recommendation of safety monitoring committee to raise seizure threshold). Paracervical block with 10ml of 1% lidocaine (1ml 1% nonbuffered lidocaine on the anterior and posterior lip of the cerivx and then 4.5ml of 1% lidocaine at the 4‐ and 8‐o'clock postitions). Five experienced surgeons performed all abortions with an electric vacuum pump after dilation of the cervix. |
| Outcomes |
Pain rated by subjects using a 100mm visual analog scale (VAS; anchors: 0 = none, 100 mm = worst imaginable) at several points in time: 1) before the procedure started (anticipatory pain); 2) following speculum insertion; 3) after intrauterine infusion; 4) following dilation; 5) after suction aspiration; and 6) 30 minutes later in the recovery room.
Assessment of overall satisfaction level regarding the abortion experience using the VAS, before discharge. Subjects performed all VAS scales concurrently with each step and not from memory. |
| Notes |
Serum lidocaine were drawn in a subset (n=8) of subjects to obtain safety data. Interim analysis after 37 subjects studied because of concerns of lidocaine toxicity. Some subjects had lidocaine side effects (including ear ringing, perioral numbness and tingling), but none had overt symptoms of severe toxicity (i.e. seizuers, cardiac arrest or loss of consciousness) or toxic serum range of lidocaine. Safety monitoring committee recommended diazepam for all subsequent subjects to raise seizure threshold.
3 women withdrew from the trial prior to receiving study medication; 2 were in the lidocaine groups the other in the saline group. One protocol violation in the saline group with the inadvertent enrollment of a subject without premedication with ibuprofen, but diazepam only. Analysis in accordance with intent to treat. |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Allocation concealment? |
Low risk |
A ‐ Adequate |
