Which blood test results would confirm a diagnosis of appendicitis?

UPUMS Nsg.Officer-2024

Medical & Surgical Nursing

Medium

Appeared in: UPUMS Nsg.Officer-2024

Explanation

A White Blood Cell (WBC) count of 13,000/mm³ is elevated above the normal adult range of 4,000–11,000/mm³, a condition known as leukocytosis.
Leukocytosis is a classic sign of the body's systemic inflammatory response to an infection, which is the underlying cause of acute appendicitis.
In patients with appendicitis, the WBC count is typically mildly elevated, often falling in the 11,000-16,000/mm³ range, making 13,000/mm³ a characteristic finding.

Option A: An RBC count of 4.5 million cells/mm³ is within the normal physiological range (approximately 4.5–5.5 million cells/mm³) and does not indicate an infectious or inflammatory process.
Option B: A platelet count of 300,000 cells/mm³ is a normal value, as the typical range is 150,000–450,000 cells/mm³. It is not used to diagnose appendicitis.
Option D: The heterophil antibody test (or Monospot test) is specific for diagnosing infectious mononucleosis, an illness caused by the Epstein-Barr virus. It has no role in diagnosing appendicitis.

Clinical Relevance

Nursing practice connection: Use the key finding related to Interpretation of laboratory results for acute appendicitis diagnosis to guide bedside assessment, documentation, and the next nursing action.
A nurse observing an elevated WBC count in a patient with abdominal pain must promptly communicate this finding to the healthcare provider, as it is a key piece of data supporting an appendicitis diagnosis and the need for urgent evaluation.
Monitoring trends in WBC is crucial. A sudden sharp increase or a count exceeding 20,000/mm³ could signal a complication like appendix perforation, requiring immediate intervention.
What if? If the patient's WBC was normal but they had classic right lower quadrant pain, the nurse should anticipate that the provider might still proceed with imaging (like an ultrasound or CT scan), as a normal WBC count does not definitively rule out appendicitis, especially in the early stages.

How to Approach the Question

First, identify the core of the question: which lab value points to appendicitis?
Recall that appendicitis is an infection and inflammation of the appendix.
Connect the pathophysiology (infection/inflammation) to the corresponding blood test. The body responds to infection by increasing its white blood cell (WBC) production.
Evaluate each option by comparing the given value to its normal range. Check if the RBC and platelet values are normal.
Recognize that the heterophil test is for a different disease (mononucleosis) and is therefore irrelevant.
Conclude that the elevated WBC count is the only abnormal value that aligns with an infectious process like appendicitis.

Concept Tested & Keywords

Concept Tested: Interpretation of laboratory results for acute appendicitis diagnosis.
Stem keywords: blood test, diagnosis, appendicitis
Lead-in keywords: confirm
Negative lead-in flag: false

QLYcRtqJ8fIzIfwTsnYXzf

E6 Nelson Textbook of Pediatrics(2024) — Volume 2 p. 181-183

E6 Pathology-Vandana Puri & Kavita Gaur Textbook of Pathology and Genetics p. 384-386