Utility of Post Op Lab Testing Questioned for Some Gynecologic Patients

Routine postoperative laboratory testing may be unnecessary in some gynecological patients, according to two abstracts presented at the Society of Gynecologic Oncology’s (SGO’s) Annual Meeting on Women’s Cancer (March 19-22, San Diego).

The first study found that the likelihood of detecting postoperative laboratory abnormalities is low in asymptomatic patients following robotic hysterectomies in endometrial cancer patients. The researchers, led by Josephine Kim, M.D., an obstetrics fellow from the University of Chicago in Illinois, suggest that routine laboratory tests in asymptomatic patients following uncomplicated surgery may be unwarranted.

The researchers identified 380 patients without comorbidities who underwent uncomplicated surgery. The patients had a median age of 62 years, median body mass index of 32, and median length of stay of one day. All patients had at least one postoperative complete blood count.

While 54 percent of patients had abnormal postoperative hemoglobin values, only one patient (0.5 percent) required a blood transfusion for symptomatic anemia. Similarly, 54 percent of patients had abnormal postoperative white blood cell counts, but only two patients (1 percent) required intervention, both for symptomatic urinary tract infections. Results of complete blood counts alone prompted no intervention in asymptomatic patients.

On the first postoperative day, the vast majority of patients (91 percent) underwent a basic metabolic panel. Potassium levels were corrected in 39 asymptomatic patients (11 percent) even though most (54 percent) fell in the normal range. Similarly, more than one-third of asymptomatic patients (37 percent) had corrective interventions for postoperative magnesium levels, despite nearly two-thirds (64 percent) falling in the normal range. Two asymptomatic patients had abnormal routine postoperative laboratory results that led to intervention—one for elevated creatinine consistent with acute kidney injury and one with hyponatremia.

The authors report that the charges for routine postoperative laboratory testing totaled $260,882 (an average of $782 per patient), suggesting that cutting these tests in asymptomatic patients could yield measurable savings.

In the second study, researchers from University Hospitals in Cleveland, Ohio, retrospectively identified 235 patients who underwent minimally invasive surgery for endometrial cancer (either standard laparoscopy [LSC] n=138 or robotic-assisted surgery n=97) from 2010 to 2015. Baseline demographics and perioperative characteristics were evaluated. Clinical hemodynamic instability was defined as development of tachycardia, hypotension, low urine output, or dizziness.

The researchers found that patients with a lower body mass index were significantly more likely to have a greater decrease in hemoglobin, while surgical history, surgery/anesthesia time, blood loss, lymphadenectomy, use of preoperative anticoagulation, and use of postoperative ketorolac were not associated with greater decreases in hemoglobin. In total, 52 patients (22.1 percent) had at least one sign or symptom of hemodynamic instability postoperatively. Clinically symptomatic patients were significantly older and had significantly greater decreases in hemoglobin, compared to asymptomatic patients. Only symptomatic patients (n=5) required postoperative blood transfusions.

“These results call into question the utility of performing routine hemoglobin testing after minimally invasive surgery for endometrial cancer,” writes co-author John Nakayama, M.D. “Hemoglobin testing may only be necessary for patients who develop signs or symptoms of hemodynamic instability. Omission of this routine test in asymptomatic patients could result in sizable health care cost savings. In addition, these results provide more data that could be used to support the safety of same-day discharge after minimally invasive surgery for endometrial cancer in appropriately selected patients.”

Takeaway: New evidence shows that postoperative blood tests may be unnecessary following some gynecologic surgeries. Reducing this unnecessary testing could yield cost savings, and possibly shorter discharges for some patients.