Clarification on Postoperative Day 1 CBC and CMP Testing
Routine CBC and CMP on postoperative day 1 are NOT necessary for all patients—they should be obtained selectively based on clinical indication, surgical risk, and specific patient factors. 1, 2
When POD1 Labs ARE Indicated
The following clinical scenarios warrant CBC and CMP on postoperative day 1:
- Patients with perioperative clinical concerns (bleeding, hemodynamic instability, oliguria, altered mental status) 2
- Insulin-dependent diabetics requiring glucose monitoring 2
- Therapeutically anticoagulated patients at higher bleeding risk 2
- High-risk procedures such as TIPS placement, where routine labs (CBC, CMP, PT/INR) should be obtained the day following the procedure 1
- Patients on ruxolitinib or similar medications requiring CBC and CMP monitoring every 2-4 weeks until doses stabilize 1
- Patients with sickle cell disease undergoing surgery, where routine laboratory testing (CBC, reticulocytes, renal/liver function) is recommended preoperatively and postoperatively as clinically indicated 1
When POD1 Labs Are NOT Routinely Needed
For uncomplicated elective surgeries in otherwise healthy patients, routine POD1 bloodwork can be safely omitted without increasing complications. 2
A 2023 study of 303 bariatric surgery patients demonstrated that 84.5% safely avoided POD1 bloodwork when there were no clinical concerns, with no significant differences in transfusion rates, reoperation, or 30-day ED visits compared to routine testing. 2 This approach saved approximately $6,602 in laboratory costs and reduced patient discomfort. 2
The Key Distinction
The critical factor is clinical indication, not arbitrary timing. 1, 2 Hemoglobin/hematocrit may be obtained on the same day of surgery if clinically indicated, rather than waiting until POD1. 1 Pre-discharge imaging is not indicated in most patients. 1
Common Pitfalls to Avoid
- Ordering reflexive POD1 labs without clinical justification wastes resources and provides minimal clinical benefit in uncomplicated cases 2
- Failing to obtain labs when clinically indicated (active bleeding, hemodynamic changes, oliguria) can delay recognition of complications 1, 2
- Confusing preoperative screening requirements with postoperative monitoring needs—preoperative CBC and CMP are recommended for risk stratification in many surgeries, but this does not automatically mandate POD1 repeat testing 1