Reducing Postoperative Blood Tests in Colorectal Surgery: A Dual-Cohort Before-and-After Study

Area of Science:

• Colorectal Surgery
• Patient Safety
• Healthcare Management

Background:

• Routine postoperative blood testing in colorectal surgery is often excessive and not clinically indicated.
• Overtesting leads to iatrogenic anemia, increased costs, and patient discomfort.
• Compliance with guidelines for blood test rationalization, such as Enhanced Recovery After Surgery (ERAS), is inconsistent, especially in acute settings.

Purpose of the Study:

• To evaluate the impact of low-cost interventions on reducing non-indicated postoperative blood tests in elective and acute colorectal surgery.
• To improve adherence to ERAS Society and NHS England guidelines for blood test ordering.

Main Methods:

• A dual-cohort, before-and-after interventional study in an NHS colorectal unit.
• Interventions included staff education, visual ward posters, and a structured proforma for blood test ordering.
• Assessed elective patients against ERAS guidelines and acute patients against NHS England guidance.

Main Results:

• Routine postoperative day 2 blood testing in elective patients decreased from 90% to 26% (71% relative reduction).
• In acute patients, total blood tests reduced by 63%, with unnecessary tests falling from 58.3% to 23.3%.
• Significant reductions were observed for phosphate, magnesium, and bone profile tests; no adverse safety signals were identified.

Conclusions:

• Simple, low-cost interventions effectively improved guideline compliance for blood test ordering in colorectal surgery.
• Acute colorectal surgery patients are a key group for ERAS implementation to reduce unnecessary blood tests.
• Findings support broader adoption of indication-based blood test requesting in surgical practice.