Pocket ObGyn – Dysmenorrhea – SỔ TAY LÂM SÀNG

Pocket ObGyn – Dysmenorrhea
See Abbreviations

Modified from Hoffman BL, Schorge JO, Schaffer JI, et al., eds. Williams Gynecology. 2nd ed. New York, NY: McGraw-Hill; 2012.

Definition & Epidemiology

Dysmenorrhea = painful One of the most common gyn complaints.
Primary dysmenorrhea (PD) = Menstrual pain in the absence of underlying pathologic pelvic Usually seen near time of menarche. Affects 43–91% of adols (depending on study criteria) (Contraception 2010;81:185). PD ¯’s w/ age. Highest in 20–24 yo’s & ¯’s thereafter (Obstet Gynecol 2006;108:428).
Secondary dysmenorrhea (SD) = Menstrual pain d/t pelvic condition or pathology. Risks: BMI <20, nulliparity, depression, premenstrual syn, sterilization, PID, h/o sexual assault, & heavy

Pathophysiology & Etiology

PD d/t PGF2a in secretory endometrium ® uterine contractility ® painful menstrual cramps (Contraception 2010;81:185)
SD most commonly d/t endometriosis, followed by adenomyosis, & Other causes:

Gyn etiology: Cervical stenosis (hematometria), PID, adhesive dz, fibroids, pelvic congestion, & congen malformations.

Nongynecologic etiology: Psychosomatic, IBS, inflamm bowel dz, UTI/dz, kidney stones, IC.

Clinical Manifestations & Diagnosis

PD: Presents w/ or shortly after menarche. Midline, cramping pain, beginning w/ onset of Pain worst 1st 24–36 h, c/w the highest levels of PG release. Resolves over 12–72 h (Contraception 2010;81:185). Dx based on hx & nml pelvic exam. May be a/w HA, N/V, backache, & diarrhea. May occur as late as 1 y after menarche, but unlikely & should suspicion for SD.
SD: Dx based on inconsistent hx & abn pelvic exam (eg, pelvic mass, abn vaginal discharge, pelvic tenderness not limited to time of menses). Consider SD if no resp to NSAIDs & OCPs, or if sx follow years of painless

Treatment & Medications

PD:

NSAIDs: 1st-line therapy. Works in ~90% of pts. Start on day prior to menses, or at onset. If 1 NSAID is ineffective, switch to different class. Specific COX-2 inhibs (celecoxib) also shown to be effective.

OCP: Suppress ovulation & ¯ endometrial thickening ® ¯ PG ® ¯ pain. Low-dose OCs (20 mg ethinyl estradiol) can ¯ sx. Continuous OC (vs. monthly) will ¯ pain longer, but s/e extended regimen = breakthrough bleeding.

Depot medroxyprogesterone (150 mg IM q3mo): Not specifically studied in this pop. Presumed to ¯ endometrium thickness ® ¯ PG ® ¯ pain.

Levonorgestrel-releasing IUD: Profound local effect ® suppression of endo- metrial growth ® improv in sx.

Nifedipine (20–40 mg QD): Known effect on uterine contractility, but 1st-line therapy so effective that it is rarely req. S/e = flushing, tachy, & HAs.

Narcotics: Should be used as last-line therapy

Endometrial ablation: ¯ endometrium ® ¯ sx. Not for those desiring fertility.

Nerve ablation: Observational studies support LUNA & presacral neurectomy to interrupt cervical pain fibers. Cochrane review sugg presacral neurectomy > LUNA > placebo/no rx. But insuff evid to recommend either (Obstet Gynecol 2006;108:428).