The Murray and Washington grading system for sputum smears uses leukocytes and oral epithelial cells to help separate suitable from suboptimal specimens.
leukocytes per 10x objective (low power) |
epithelial cells per 10 x objective (low power) |
Group |
< 10 |
> 25 |
1 |
10-25 |
> 25 |
2 |
> 25 |
> 25 |
3 |
> 25 |
10-25 |
4 |
> 25 |
< 10 |
5 |
Interpretation:
• Groups 1 through 4 show large numbers of epithelial cells, indicating contamination with oropharyngeal secretion. Cultures are typically deferred on these specimens.
• Group 5: clinically relevant. Cultures are typically performed on these specimens.
Patterns not "Grouped" above
leukocytes per 10x objective (low power) |
epithelial cells per 10 x objective (low power) |
< 10 |
10-25 |
< 10 |
< 10 |
10-25 |
10-25 |
10-25 |
< 10 |
I would not culture the first three, but would the last one.
Purpose: To evaluate the quality of a sputum specimen and to identify those contaminated with oral flora using the score of Murray and Washington.
Specialty: Infectious Diseases, Clinical Laboratory, Pulmonology
Objective: other testing
ICD-10: R09.3,