Routine preop tests catch hidden risks in outpatient cosmetic surgery, Canadian study finds

Editor's Note

As aesthetic procedures continue to migrate into freestanding ambulatory surgery centers (ASCs), a new Canadian study argues that routine laboratory tests and electrocardiograms—often labeled “low‑value” in hospitals—remain a critical safety net when emergency back‑up is miles away. The manuscript was published by the Aesthetic Surgery Journal on April 5.

Researchers at a single Ontario ASC reviewed 2,596 consecutive cosmetic cases over 40 months (January 2019 to May 2022). After exclusions, 2,581 patients—91% female, average age of 38—were analyzed. Every patient received a history and physical plus basic bloodwork; ECGs were added for anyone ≥45 years or with cardiac history. 

Abnormal findings were common. One‑third of patients (32.5%) had atypical bloodwork—most frequently prolonged aPTT or low hemoglobin—and 9.3% showed ECG irregularities. Fully 84% of the bloodwork flags and 75% of the ECG flags came from “supplementary” screens ordered for otherwise healthy patients. 

Care changed in nearly 1 in 10 cases. Abnormal results prompted 293 alterations in perioperative management for 242 patients (9.4%). Adjustments included new medications such as iron or antihypertensives (35.5%), additional imaging or labs (26.6%), specialist consults (22.9%), and surgery postponement or cancellation (15%). Pregnancy tests alone delayed 15 procedures. 

Who was most affected? Patients aged ≥50, those with comorbidities, higher ASA class, and—surprisingly—women were significantly more likely to need a change in care. Logistic‑regression showed that an abnormal history/physical carried the highest odds of triggering an intervention (OR 5.7), followed by ECG (OR 3.8) and bloodwork (OR 2.2). 

Lead author Natalia Ziolkowski, MD, PhD, FRCS(C), said the findings challenge “resource‑conservation” campaigns such as Choosing Wisely, which recommend limiting baseline tests before low‑risk surgery. While that approach may work in hospitals with immediate lab, imaging, and transfusion support, the authors argue ASCs operate without those “guardrails” and therefore need broader screening protocols to uncover silent anemia, coagulation issues, or cardiac anomalies before same‑day discharge.

The study suggests a two‑step pregnancy check—serum hCG during preop labs plus day‑of‑surgery urine testing—to minimize late cancellations, and calls on specialty societies to develop ASC‑specific guidelines rather than extrapolating hospital data. Although retrospective and single‑center, the study is one of the largest to quantify how often routine testing alters management in cosmetic surgery. With payers and regulators pressing for cost savings, the authors contend that a blanket cutback on preop investigations could expose ASC patients—and the centers’ accreditation status—to avoidable risk.