Skip to main content
Ch. 17 Blood
Hoehn - Marieb Human Anatomy & Physiology, 12th edition
Hoehn, Haynes, Abbott12th EditionMarieb Human Anatomy & PhysiologyISBN: 9780138242732Not the one you use?Change textbook
Chapter 17, Problem 27

Mr. Chu has been scheduled for surgery to have his arthritic hip replaced. His surgeon tells him he must switch from aspirin to acetaminophen for pain control before his surgery. Why?

Verified step by step guidance
1
Understand the role of aspirin and acetaminophen in pain management: Aspirin is a nonsteroidal anti-inflammatory drug (NSAID) that also has blood-thinning (anticoagulant) properties, while acetaminophen primarily acts as a pain reliever and fever reducer without significant effects on blood clotting.
Recognize the importance of blood clotting during surgery: Proper blood clotting is essential to prevent excessive bleeding during and after surgical procedures.
Identify the effect of aspirin on blood clotting: Aspirin inhibits platelet aggregation by irreversibly blocking the enzyme cyclooxygenase, which reduces the production of thromboxane A2, a molecule that promotes platelet clumping and clot formation.
Explain why aspirin is contraindicated before surgery: Because aspirin impairs platelet function and prolongs bleeding time, continuing aspirin before surgery increases the risk of excessive bleeding during the operation.
Understand why acetaminophen is preferred before surgery: Acetaminophen does not affect platelet function or blood clotting, making it a safer choice for pain control prior to surgery to minimize bleeding risks.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
2m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Aspirin's Effect on Blood Clotting

Aspirin inhibits platelet function, reducing blood clotting ability. This increases the risk of excessive bleeding during and after surgery, which is why patients are often advised to stop aspirin before surgical procedures.
Recommended video:
10:05
Coagulation (Blood Clotting)

Acetaminophen as an Alternative Pain Reliever

Acetaminophen provides effective pain relief without affecting platelet function or blood clotting. It is considered safer for managing pain before surgery because it does not increase bleeding risk.
Recommended video:
4:40
Alternative Pathway

Preoperative Medication Management

Managing medications before surgery is crucial to minimize complications. Surgeons often recommend stopping drugs like aspirin that affect bleeding, while substituting safer alternatives to ensure pain control without increasing surgical risks.
Recommended video:
Guided course
2:16
Bone of the Lower Limb Example 1