Pulse Oximetry as an Aid to Rule Out Pneumonia among Patients with a Lower Respiratory Tract Infection in Primary Care
Chloé Fischer,
José Knüsli,
Loïc Lhopitallier,
Estelle Tenisch,
Marie-Garance Meuwly,
Pauline Douek,
Jean-Yves Meuwly,
Valérie D’Acremont,
Andreas Kronenberg,
Isabella Locatelli,
Yolanda Mueller,
Nicolas Senn,
Noémie Boillat-Blanco
Affiliations
Chloé Fischer
Infectious Diseases Service, Lausanne University Hospital and University of Lausanne, 1011 Lausanne, Switzerland
José Knüsli
Infectious Diseases Service, Lausanne University Hospital and University of Lausanne, 1011 Lausanne, Switzerland
Loïc Lhopitallier
Gare10 Lausanne General Practice, 1011 Lausanne, Switzerland
Estelle Tenisch
Department of Radiology, Lausanne University Hospital and University of Lausanne, 1011 Lausanne, Switzerland
Marie-Garance Meuwly
Department of Radiology, Lausanne University Hospital and University of Lausanne, 1011 Lausanne, Switzerland
Pauline Douek
Department of Radiology, Lausanne University Hospital and University of Lausanne, 1011 Lausanne, Switzerland
Jean-Yves Meuwly
Department of Radiology, Lausanne University Hospital and University of Lausanne, 1011 Lausanne, Switzerland
Valérie D’Acremont
Digital Global Health Department, Centre for Primary Care and Public Health (Unisanté), University of Lausanne, 1011 Lausanne, Switzerland
Andreas Kronenberg
Medix General Practice, 3010 Bern, Switzerland
Isabella Locatelli
Department of Education, Research, and Innovation, Centre for Primary Care and Public Health (Unisanté), University of Lausanne, 1011 Lausanne, Switzerland
Yolanda Mueller
Department of Family Medicine, Centre for Primary Care and Public Health (Unisanté), University of Lausanne, 1011 Lausanne, Switzerland
Nicolas Senn
Department of Family Medicine, Centre for Primary Care and Public Health (Unisanté), University of Lausanne, 1011 Lausanne, Switzerland
Noémie Boillat-Blanco
Infectious Diseases Service, Lausanne University Hospital and University of Lausanne, 1011 Lausanne, Switzerland
Guidelines recommend chest X-rays (CXRs) to diagnose pneumonia and guide antibiotic treatment. This study aimed to identify clinical predictors of pneumonia that are visible on a chest X-ray (CXR+) which could support ruling out pneumonia and avoiding unnecessary CXRs, including oxygen saturation. A secondary analysis was performed in a clinical trial that included patients with suspected pneumonia in Swiss primary care. CXRs were reviewed by two radiologists. We evaluated the association between clinical signs (heart rate > 100/min, respiratory rate ≥ 24/min, temperature ≥ 37.8 °C, abnormal auscultation, and oxygen saturation 100/min, respiratory rate ≥ 24/min, temperature ≥ 37.8 °C, or abnormal auscultation). Out of 469 patients from the initial trial, 107 had a CXR and were included in this study. Of these, 26 (24%) had a CXR+. We found that temperature and oxygen saturation were associated with CXR+. A CDR based on the presence of either temperature ≥ 37.8 °C and/or an oxygen saturation level < 95% had a sensitivity of 69% and a negative likelihood ratio (LR−) of 0.45. The CDR from the meta-analysis had a sensitivity of 92% and an LR− of 0.37. The addition of saturation < 95% to this CDR increased the sensitivity (96%) and decreased the LR− (0.21). In conclusion, this study suggests that pulse oximetry could be added to a simple CDR to decrease the probability of pneumonia to an acceptable level and avoid unnecessary CXRs.
