What preoperative lab tests are indicated for a 37-year-old woman with a fibroid uterus undergoing laparoscopic myomectomy for menorrhagia?

Preoperative Laboratory Testing for Laparoscopic Myomectomy

For a healthy 37-year-old woman undergoing laparoscopic myomectomy for menorrhagia due to fibroids, a complete blood count (CBC) is the only preoperative laboratory test indicated.

Rationale for Minimal Testing

The patient presents with several factors that suggest minimal preoperative testing is appropriate:

• Young age (37 years old)
• Good functional status (walks several miles daily without difficulty)
• No chronic medications
• Normal vital signs
• No significant medical comorbidities
• BMI of 27 (mildly overweight but not obese)

Complete Blood Count (CBC)

A CBC is indicated for the following reasons:

• Menorrhagia history: The patient has a history of heavy menstrual bleeding, which puts her at risk for anemia 1
• Surgical blood loss risk: Laparoscopic myomectomy can be associated with significant blood loss, with median perioperative blood loss of 536.3 cc reported in recent studies 2
• Transfusion risk assessment: Preoperative hemoglobin/hematocrit values are important to identify patients who may be at higher risk for requiring blood transfusion 3

Recent research shows that preoperative hematocrit ≤35.0% is independently associated with increased risk for blood transfusion during laparoscopic myomectomy 3.

Other Laboratory Tests NOT Routinely Indicated

1. Coagulation studies: Not routinely indicated unless the patient has a history of bleeding disorders or is on anticoagulation therapy 1

2. Chemistry panel: Not indicated for this healthy patient with no medical comorbidities

3. Urinalysis: Not indicated for this type of procedure in a healthy patient

4. Pregnancy test: While not mentioned in the evidence provided, this would be standard practice before any gynecologic procedure

Special Considerations for Myomectomy

The American Society of Anesthesiologists (ASA) guidelines recommend that preoperative laboratory tests should be ordered based on the patient's condition and the planned procedure 1. For this patient:

• The risk of significant blood loss during laparoscopic myomectomy is real - studies show that blood loss correlates with fibroid size, number, and operative time 4
• Blood loss during myomectomy can be underestimated intraoperatively, with calculated perioperative blood loss often exceeding estimated blood loss 2

Potential Risk Factors for Increased Blood Loss

Factors associated with increased blood loss during laparoscopic myomectomy include:

• Larger fibroid size (>250g specimen weight)
• Multiple intramural fibroids (≥5)
• Longer operative time (≥197 minutes)
• Fibroids penetrating the uterine cavity 3, 5

Conclusion

For this otherwise healthy 37-year-old woman with menorrhagia due to fibroids, a CBC is the only preoperative laboratory test indicated. This will help assess for anemia related to her menorrhagia and establish a baseline hemoglobin/hematocrit level before a procedure that carries risk for blood loss.