1. The Value of a Chest X-Ray in Diagnosing Pneumonia in SIRS Patients Lacking Respiratory Symptoms in York Hospital’s Emergency Department
Michelle Lynch Department of Biological Sciences, York College of Pennsylvania
Radiologyinfo.org
Introduction
Methods
Results
Systemic Inflammatory Response Syndrome (SIRS)
Bodily response caused by a wide variety of issues
Related to sepsis, which is SIRS specifically caused by infection
Requires two or more of the following symptoms:
Tachycardia [>90 bpm]
Hypo/Hyperthermia [<96.0 °F or >100.4 °F ]
High Respiratory Rate [>20 breaths/minute]
Low/High WBC [<4,000/μL or >12,000/μL]
Pneumonia
Infection in one or more lobes of the lungs
Symptoms include: cough, fever, shortness of breath
5.6 million cases per year in U.S., 1/5 requiring hospitalization
Leading cause of death by infectious disease
Chest X-Ray
Required in the diagnosis of pneumonia
Infection infiltrates are seen as white opaque patches
Benefits: clear indicator of infiltrates
Drawbacks: costly ($50-$400), radiation exposure
Retroactive chart review of York Hospital Emergency Department patients receiving a chest x-ray in Dec. 2010
Those with at least two SIRS criteria were included
Pediatric and DNR/comfort care only patients and those with known pneumonia or a chronic abnormal chest x-ray were excluded
Charts were reviewed to determine:
Presence or absence of respiratory symptoms at ED presentation Respiratory Symptom (RS): Dyspnea, Tachypnea, Cough, Chest Pain, Hypoxia, and Focal Lung Findings
Radiology interpretation of ED chest x-ray
Discharge Diagnosis (Gold standard for pneumonia diagnosis )
Fisher’s exact test and descriptive statistics were used
Table 1. Effectiveness of methods in the diagnosis of pneumonia
History and Physical
Chest X-Ray
Sensitivity
100%
(95% CI: %)
65%
(95% CI: 43-83%)
Specificity
23%
(95% CI: 17-30%)
86%
(95% CI: 80-91%)
+ Likelihood Ratio
1.3
(95% CI: )
4.6
(95% CI: )
- Likelihood Ratio
(95% CI: 0-0.8)
0.4
(95% CI: )
1053 charts reviewed
23 (14.9%) with Pneumonia
0 (0%) with Pneumonia
39 with no RS
154 with one or more RS
193 charts included
860 Excluded
Conclusion
A history and physical was more effective in diagnosing pneumonia than a chest x-ray (sensitivity 100% and 65% respectively)
None of the patients with SIRS lacking respiratory symptoms were diagnosed with pneumonia and Chest X-rays were not necessary in their diagnosis
Combined with supportive findings from additional studies, chest x-rays can be used more judiciously to limit radiation exposure and reduce medical costs
Objectives
To determine the prevalence of pneumonia and the predictive properties of a chest x-ray in the evaluation of SIRS for patients with and without respiratory symptoms
Hypothesis: Patients with SIRS criteria and no respiratory symptoms have a lower prevalence of pneumonia and do not require a chest x-ray on initial work up
References
Bone, R., et al American College of Chest Physicians/Society of Critical Care Medicine Consensus Conference: definitions for sepsis and organ failure and guidelines for the use of innovative therapies in sepsis. Chest 101:
Lutfiyya, M., et al Diagnosis and treatment of community-acquired pneumonia. Am. Family Physician 73:
Verma, V., et al The utility of routine admission chest X-ray films on patient care. European Journal of Internal Medicine 22:286–288.
Acknowledgements
Thank you to Dr. Kochert, Dr. Ryles, Dr. Lalani, and Mrs. Stahlman from York Hospital and Dr. Kaltreider and Dr. Boehmler from York College