PoCUS for Acute Pelvic Pain in Gynecology: Minimal Protocol
The Role of PoCUS in Acute Pelvic Pain
The ISUOG 2025 practice guidelines for point-of-care ultrasound in obstetrics and gynecology systematically describe PoCUS as a distinct clinical scenario performed by the attending physician at the patient's bedside for immediate decision-making. In gynecology, for acute pelvic pain, PoCUS does not replace expert transvaginal examination, the IOTA protocol, Doppler assessment of a tumor, or planned description of pelvic organs. Its goal is narrower: to quickly identify ultrasound signs of conditions that alter management within minutes or hours.
A key principle of the ISUOG consensus is that each PoCUS scenario should be tied to a specific clinical question, performed by a trained operator, documented, and have a pre-defined escalation path for uncertain or pathological results.
Who Should Undergo the Minimal Protocol
The protocol is applicable for sudden or increasing pelvic pain in patients of reproductive age, perimenopausal, and postmenopausal women if gynecological causes of pain are considered based on the clinical picture. Priority scenarios include: positive or unknown pregnancy test, syncope or hemodynamic instability, pain radiating to the shoulder or rectum, unilateral pain in the adnexal region, vomiting associated with pelvic pain, fever, and adnexal tenderness.
Before the examination, clinical data that PoCUS does not replace are important: date of last menstruation, likelihood of pregnancy, hCG test result, nature of pain, temperature, hemodynamics, presence of intrauterine contraception, recent interventions, and history of cysts, endometriosis, or pelvic inflammatory diseases.
Minimal Clinical Questions
Instead of a full descriptive protocol, PoCUS is formulated as a series of binary or categorical questions. This approach reduces the risk of 'false confidence' and helps the physician stay within their competence.
| PoCUS Clinical Question | What to Look For | Interpretation | Tactical Significance |
|---|---|---|---|
| Is there an intrauterine pregnancy? | Gestational sac in the uterine cavity with embryonic structures at the appropriate gestational age | Positive / not confirmed / indeterminate | In the presence of pain and instability, even a confirmed uterine pregnancy does not exclude other acute pathology |
| Are there signs of ectopic pregnancy? | Adnexal mass, extrauterine gestational sac, free fluid, uterine findings inconsistent with clinical picture | Suspicion / no clear signs / indeterminate | Urgent escalation is needed, especially with free fluid or instability |
| Is there significant free fluid? | Fluid in the Douglas pouch, spreading above the pelvis, echogenic content | Absent / present / widespread or echogenic | Suspicion of bleeding, cyst rupture, complicated ectopic pregnancy |
| Is there an adnexal mass? | Cyst, complex mass, conglomerate, tenderness on probe compression | Simple / complex / indeterminate | Determines the need for expert ultrasound, gynecologist consultation, or surgical strategy |
| Are there signs of torsion? | Enlarged painful ovary, peripheral follicles, associated mass, free fluid, Doppler changes | Suspicion / no signs detected / indeterminate | Absence of Doppler changes should not negate clinical suspicion |
| Are there signs of inflammatory complication? | Complex adnexal mass, tubo-ovarian conglomerate, fluid, marked tenderness | Suspicion / no clear signs / indeterminate | Laboratory correlation, antibacterial strategy, and extended imaging are needed |
Scanning Technique: Transabdominal and Transvaginal
The minimal protocol usually begins with a transabdominal overview. It is useful in cases of instability, marked tenderness, inability for vaginal access, and for detecting fluid beyond the pelvis. The uterus, bladder as an acoustic window, Douglas pouch, lateral pelvic areas, and accessible abdominal sections are evaluated.
Transvaginal access provides higher resolution for the uterus, endometrium, tubal-ovarian area, and early pregnancy. It is preferable if the patient's condition allows, there are no contraindications, and consent is obtained. A combined approach is permissible in PoCUS: the transabdominal phase addresses the question of free fluid and large pathology, while the transvaginal phase clarifies the uterus and adnexa.
Mandatory Examination Sequence
- Uterus and uterine cavity. Determine the position of the uterus, presence of intrauterine pregnancy, or other obvious intrauterine cause of pain, such as voluminous content post-intervention.
- Douglas pouch. Note the absence, presence, or widespread nature of free fluid; consider blood or pus in the appropriate clinical context if echogenic fluid is present.
- Right and left ovary. Locate both ovaries, visually compare sizes, assess tenderness with gentle compression, presence of cysts or complex masses.
- Tubal-ovarian area. Look for a mass separate from the ovary, conglomerate, hydrosalpinx-like structure, or painful infiltrate.
- Doppler as indicated. Use color and spectral Doppler as an adjunct, not as the sole criterion for torsion or tissue viability.
- Extended view. In cases of free fluid, instability, or severe pain, examine accessible upper abdominal pockets transabdominally.
Unknown Pregnancy: Safety First
In a patient of reproductive age, pregnancy status should be considered unknown until confirmed by laboratory or reliable clinical means. In this scenario, PoCUS is primarily aimed at ruling out immediate threats: hemoperitoneum, suspicion of ectopic pregnancy, and absence of definitive signs of intrauterine pregnancy with a positive test.
A normal or inconclusive uterine picture is not a standalone basis to exclude ectopic pregnancy. If the pregnancy test is positive, pain persists, and intrauterine pregnancy is not confirmed, the PoCUS result should be classified as indeterminate or suspicious, and the patient should be referred for urgent expert evaluation according to local protocol.
Adnexal Torsion: Do Not Rely Solely on Doppler
Torsion remains a clinical-ultrasound diagnosis. For PoCUS, cumulative signs are important: unilateral acute pain, vomiting, enlarged painful ovary, peripheral follicle arrangement, associated cyst or tumor-like mass, free fluid. Color flow may persist, so its presence does not exclude torsion.
The minimal formulation should be practical: 'ultrasound signs supporting clinical suspicion of torsion' or 'no clear signs of torsion obtained, but with persistent clinical suspicion, gynecologist consultation is required.' Such a record aligns with ISUOG logic: PoCUS aids in routing but should not delay surgical decision-making.
Free Fluid and Cyst Rupture
Free fluid in the pelvis with acute pain is interpreted only in conjunction with clinical presentation, pregnancy, and hemodynamics. A small volume of anechoic fluid may be nonspecific. Echogenic fluid, spread beyond the pelvis, combination with adnexal mass, or positive pregnancy test are high-risk signs requiring urgent escalation.
In suspected cyst rupture, PoCUS should describe the side, presence of residual cystic or complex mass, and fluid characteristics. Absence of cyst visualization does not exclude its rupture if there is free fluid and typical clinical presentation.
How to Document PoCUS
Documentation should be brief but reproducible. Indication, access, visualization quality, answers to minimal questions, key images or clips, limitations, and plan are necessary. Phrases like 'normal' or 'no pathology' are undesirable if only a focused protocol is performed.
Optimal report structure: 'Pelvic PoCUS for acute pain. Transabdominal/transvaginal. Intrauterine pregnancy: confirmed/not confirmed/not assessed. Free fluid: none/present/echogenic/widespread. Adnexa: no obvious mass/mass on right or left/not visualized. Torsion: signs present/no clear signs/cannot be excluded. Conclusion: positive, negative, or indeterminate PoCUS; escalation recommended.'
When PoCUS is Insufficient
PoCUS is considered insufficient with poor acoustic window, inability to visualize the ovary on the side of pain, positive pregnancy test without confirmed intrauterine pregnancy, any hemodynamic instability, echogenic or widespread fluid, complex adnexal mass, suspicion of torsion, fever with adnexal conglomerate, postmenopausal bleeding, or pain with mass.
In these situations, a negative focused result should not conclude the diagnosis. The next step is expert ultrasound, gynecologist consultation, laboratory correlation, CT or MRI based on clinical indication and local protocol. The main value of PoCUS is to expedite this decision, not replace it.
Frequently asked questions
Can PoCUS rule out ectopic pregnancy?
No. PoCUS can confirm intrauterine pregnancy or identify high-risk signs, but with a positive test and absence of definitive intrauterine pregnancy, the result should be considered indeterminate or suspicious and requires escalation.
Does preserved blood flow exclude ovarian torsion?
No. Doppler is used as an adjunct method. In the presence of typical clinical and morphological signs of torsion, preserved blood flow should not delay gynecologist consultation.
How does PoCUS differ from a complete pelvic ultrasound?
PoCUS addresses pre-defined urgent questions at the patient's bedside and influences immediate management. A complete ultrasound includes systematic description of pelvic organs, differential diagnosis of masses, and expert evaluation.