How to Perform a FAST Exam: Female Pelvis Ultrasound

For blunt abdominal trauma, management differs based on hemodynamic stability (shock index = pulse/systolic BP). Stable patients (SI <1): admit for observation, perform FAST ultrasound first, then CECT if indicated. Unstable patients (SI >1): start IV fluids aggressively, avoid CECT initially, perform FAST to assess pericardial, liver, spleen, and pelvic injuries. If not stabilizing, proceed to urgent exploratory laparotomy with Pringle maneuver for hemorrhage control.

FAST (Focused Assessment with Sonography for Trauma) is a bedside ultrasound used to detect fluid in trauma patients. It examines four areas: pericardial view (heart) for cardiac tamponade, hepatorenal space (right upper quadrant) for liver bleeding, splenorenal space (left upper quadrant) for spleen bleeding, and suprapubic view (bladder) for pelvic bleeding. FAST results guide management: stable patients with positive FAST get CT scan, unstable patients with positive FAST need immediate surgery, and unstable patients with negative FAST can get CT scan.

Most commonly injured organ in abdominal trauma is the spleen. For stable blunt abdominal trauma patients, FAST ultrasound is initial investigation; contrast-enhanced CT scan is definitive. For unstable patients, FAST is preferred and midline laparotomy is performed if peritonitis is present. Penetrating abdominal injuries require careful object removal only in operating theater to avoid losing tamponade effect.

FAST is the definitive imaging modality for unstable trauma patients due to its speed and bedside availability. CT scan is the gold standard for stable patients but requires patient transport and time. For unstable patients, FAST-positive results require immediate surgical intervention; FAST-negative results do not exclude injury and may require surgical exploration. Delaying treatment for CT in unstable patients can result in patient deterioration or death. FAST scoring is reported as positive, negative, or intermediate based on fluid detection in the four examination windows. Repeat FAST should be performed in unstable patients with negative initial scan, during secondary survey if patient deteriorates, or for conservative management patients to monitor for accumulating fluid.

FAST (Focused Assessment with Sonography for Trauma) is an ultrasound examination used to detect free fluid (blood) in the abdomen and pelvis. It is performed in patients with trauma and hemodynamic instability, including pericardial window, right upper quadrant, left upper quadrant, and pelvic views. Pelvic fractures can cause massive hemorrhage due to venous plexus injury. Management includes pelvic binder application for temporary stabilization, pelvic external fixation for definitive stabilization, preperitoneal packing for tamponade, and angioembolization for controlled bleeding. Pelvic instability assessment is critical because pelvic hemorrhage is a leading cause of preventable death in trauma patients.

FAST (Focused Assessment with Sonography for Trauma) uses four views: subxiphoid (pericardial), right hypochondrium (perihepatic), left hypochondrium (perisplenic), and suprapubic (pelvic). EFAST extends to include thoracic views. For penetrating chest trauma with hemodynamic instability, EFAST is the next step. CT scan is contraindicated in hemodynamically unstable patients.

FAST requires a basic ultrasound machine with convex transducer (2.5-6 MHz) for abdominal evaluation, image recording system, ultrasound gel, and personal protective equipment. The protocol requires systematic evaluation of four 'P's windows: pericardial, perihepatic, perisplenic, and pelvic. For pericardial window, transducer is placed transversally at epigastrium directed toward cardiac apex. For perihepatic window, transducer is placed in right upper quadrant between 7th-9th intercostal spaces at midaxillary line, evaluating Space of Morrison. For perisplenic window, transducer is placed in left upper quadrant with spleen as acoustic window. For pelvic window, transducer is placed above pubic symphysis. In polytrauma context, free fluid is considered blood until proven otherwise. Minimum 200cc fluid is required for detection. E-FAST (Extended FAST) appeared in 2004, extending to thoracic region with 90% sensitivity and 99.7% specificity, superior to chest X-ray (requires 150cc vs 15cc). For E-FAST, transducer changes to linear (7.5-20 MHz). Anatomical landmarks include midclavicular line and axillary lines. Transducer is always placed in intercostal space between ribs.

The FAST (Focused Assessment with Sonography for Trauma) protocol is performed during circulation assessment to detect free fluid. Four primary windows are used: subxiphoid (cardiac), right upper quadrant (Morison's pouch), left upper quadrant (splenorenal recess), and pelvic window. The probe marker faces cranially with patient supine. eFAST adds lung windows for pneumothorax detection. Interpretation: anechoic fluid around liver/spleen indicates positive FAST. Training requires 30-50 examinations. Anatomic variations (ascites, pregnancy, adhesions) affect interpretation. The protocol is operator-dependent with significant learning curve.

FAST (Focused Assessment with Sonography for Trauma) detects intra-abdominal, intrathoracic, or pericardial blood in trauma. Based on I-DEAL principle: Indication, Display, Evaluation, Action. Extended FAST (eFAST) includes lung examination for pneumothorax. Equipment: curvilinear probe with wide field of view. Positioning: head-low for fluid near diaphragm, head-high for pelvis. Views: right upper quadrant (hepatorenal recess highest sensitivity), left upper quadrant (splenorenal recess), pelvis (retrovesical/retrovaginal pouch), cardiac (pericardial fluid), and lung (lung sliding sign). Bladder injury prevents pelvis examination.

The eFAST (Extended Focused Assessment with Sonography in Trauma) examination is a rapid ultrasound protocol used in emergency medicine to assess trauma patients by answering four critical questions: (1) Is there intraperitoneal free fluid? (2) Is there pericardial effusion? (3) Is there hemothorax or pneumothorax? (4) What is cardiac function? The exam consists of five views: right upper quadrant (Morrison's pouch), left upper quadrant (splenorenal recess), pelvis, cardiac, and bilateral lung assessment using lung sliding and M-mode for pneumothorax detection. The technique is indicated for all blunt or penetrating trauma patients, particularly hemodynamically unstable ones, as it guides treatment decisions for fluid resuscitation, chest tube placement, needle thoracostomy, or pericardiocentesis.

Ultrasound is the primary imaging modality for evaluating pelvic emergencies in females, starting with transabdominal examination using a full bladder as an acoustic window, followed by transvaginal ultrasound for detailed pelvic structure assessment; key conditions include ectopic pregnancy (6-16% of pregnancies, leading cause of first-trimester maternal death, diagnosed by absent intrauterine gestational sac with adnexal mass), ovarian torsion (characterized by enlarged (>5cm) edematous ovary with impaired blood flow, whirlpool sign, and follicular ring sign), hemorrhagic/ruptured ovarian cysts (showing lacy/spider web appearance progressing to fluid levels), and pelvic inflammatory disease/tubo-ovarian abscess; other considerations include malpositioned IUDs, ovarian vein thrombosis, and ovarian hyperstimulation syndrome, with important differentials including appendicitis and urolithiasis.

In gynecologic emergencies, asymmetric ovarian enlargement with displacement into the culdesac is the most reliable sonographic feature for diagnosing ovarian torsion, while Doppler flow assessment is unreliable for determining torsion status; pelvic inflammatory disease presents with indistinct ovarian boundaries, thickened fallopian tubes, and increased Doppler vascularity; hemorrhagic cysts show variable appearances from solid/hyperechoic acutely to cystic with concave margins over time, often mimicking neoplasms; and endometriomas appear as cystic structures with uniform low-level internal echoes and may cause complications like small bowel obstruction.

Point-of-care pelvic ultrasound is the most difficult POCUS examination to learn due to its invasive nature, unfamiliar probe, and intimate patient circumstances. However, it is one of the most commonly used examinations. Approximately 1-2% of US pregnancies are ectopic, accounting for 4% of pregnancy-related deaths. Mortality has declined from 1.15 to less than 0.5 deaths per 100,000 live births. Research by Metier & Company (2006) demonstrated that bedside transvaginal ultrasound improved early detection and decreased morbidity, with only 2.5% of ectopic patients sent home compared to 20% without ultrasound. Patient wait times decreased from 3 hours to 1 hour. Two approaches exist: transabdominal (non-invasive, less resolution) and transvaginal (detects findings up to a week earlier, detailed adnexal evaluation). Systematic technique: start with uterus in long axis, identify endometrial stripe, follow to cul-de-sac or cervix, turn 90 degrees for short axis, evaluate adnexa in both planes.

Point-of-care ultrasound (POCUS) is a critical emergency medicine tool for evaluating reproductive-age women with acute abdominal pain, particularly for detecting ectopic pregnancy, intrauterine pregnancy, and hemoperitoneum; the FAST scan is highly sensitive for detecting >100cc of intra-abdominal fluid, and serial POCUS should be performed every 30 minutes for unstable patients with changing clinical courses, as demonstrated in a case of ruptured ectopic pregnancy where bedside ultrasound findings guided urgent surgical intervention.

Three major gynecological emergencies affecting only women are pelvic inflammatory disease (PID), ectopic pregnancy, and ovarian torsion. PID shows characteristic 'cogwheel' ultrasound appearance of the fallopian tube. Ectopic pregnancy requires systematic evaluation including transvaginal ultrasound, beta HCG measurement, and clinical assessment. The beta HCG doubling time is crucial: ratio below 0.87 suggests abnormal pregnancy, 0.87-1.606 indicates ectopic pregnancy, and above 1.606 suggests normal intrauterine pregnancy. Ovarian torsion is a surgical emergency characterized by twisting of the ovary, with color Doppler showing absent or reduced blood flow. Proper probe selection is essential for effective ultrasound examination. For abdominal scanning, a convex probe (curved array) is typically used, with settings optimized for the specific organ system being evaluated. Morison's pouch (hepatorenal recess) is a critical area for detecting free fluid.