Brown identified risk factors for hypoxemia in a patient experiencing a generalized hypersensitivity reaction. These can help identify a patient who may require more aggressive management. The author is from Royal Hobart Hospital in Australia.
Manifestations of hypoxia:
(1) cyanosis
(2) oxygen saturation on room air <= 92%
Patient-specific factors associated with an increased risk for hypoxia:
(1) pre-existing respiratory disease
(2) age >= 40 years
Features of a hypersensitivity reaction associated with hypoxia:
(1) confusion
(2) stridor
(3) dyspnea
(4) hypotension
(5) wheezing
where:
• Confusion and hypotension are markers of a severe reaction, while the other 3 factors are associated with a moderate reaction.
• The odds ratio for confusion is 10. The odds ratios for the other factors range from 2.2 to 3.8
For the implementation I have tried the following scheme to capture this information.
|
Parameter |
Finding |
Points |
|
confusion |
present |
2 |
|
|
absent |
0 |
|
pre-existing respiratory disease |
present |
2 |
|
|
absent |
0 |
|
age |
>= 40 |
1 |
|
|
< 40 |
0 |
|
stridor |
present |
1 |
|
|
absent |
0 |
|
dyspnea |
present |
1 |
|
|
absent |
0 |
|
hypotension |
present |
1 |
|
|
absent |
0 |
|
wheezing |
present |
1 |
|
|
absent |
0 |
total score =
= SUM(points for all 7 parameters)
Interpretation:
• minimum score: 0
• maximum score: 9
|
Total Score |
Risk of Hypoxia |
|
0 |
low |
|
1 |
low to moderate |
|
2 |
moderate to high |
|
3 |
high |
|
4 - 9 |
very high |
Specialty: Immunology/Rheumatology
ICD-10: ,
