Do PA-Lateral CXR When You Can - It Matters

Short Attention Span Summary

AP or PA/Lateral?
Which is better for detecting parapneumonic effusion, AP chest x-ray or PA/Lateral, using CT as the gold standard?  PA/Lateral was much better, sensitivity 84% vs 67% for AP.

Spoon Feed: When patients are stable enough to send to radiology for a PA/Lateral CXR, do it.  The chance of missing significant pathology is much lower.


Abstract

Am J Emerg Med. 2016 Dec;34(12):2402-2407. doi: 10.1016/j.ajem.2016.09.021. Epub 2016 Sep 14.

Comparing posteroanterior with lateral and anteroposterior chest radiography in the initial detection of parapneumonic effusions.

Moffett BK1, Panchabhai TS2, Nakamatsu R3, Arnold FW4, Peyrani P5, Wiemken T6, Guardiola J7, Ramirez JA8.

Author information:

1Robley Rex Veterans Administration Medical Center, Louisville, KY; University of Louisville, School of Medicine, Department of Medicine, Division of General Internal Medicine, Palliative Care and Medical Education, Louisville, KY. Electronic address: bryan.moffett@va.gov.

2Robley Rex Veterans Administration Medical Center, Louisville, KY; Cleveland Clinic Foundation, Respiratory Institute. Department of Pulmonary, Allergy and Critical Care Medicine, Cleveland, OH. Electronic address: tanmay.panchabhai@dignityhealth.org.

3Robley Rex Veterans Administration Medical Center, Louisville, KY; University of Louisville, School of Medicine, Department of Medicine, Division of Infectious Diseases, Louisville, KY. Electronic address: r0naka01@louisville.edu.

4Robley Rex Veterans Administration Medical Center, Louisville, KY; University of Louisville, School of Medicine, Department of Medicine, Division of Infectious Diseases, Louisville, KY. Electronic address: f.arnold@louisville.edu.

5Robley Rex Veterans Administration Medical Center, Louisville, KY; University of Louisville, School of Medicine, Department of Medicine, Division of Infectious Diseases, Louisville, KY. Electronic address: p0peyr01@louisville.edu.

6University of Louisville, School of Medicine, Department of Medicine, Division of Infectious Diseases, Louisville, KY. Electronic address: tlwiem01@louisville.edu.

7Robley Rex Veterans Administration Medical Center, Louisville, KY; University of Louisville, School of Medicine, Department of Medicine, Division of Pulmonary Critical Care and Sleep Disorders Medicine, Louisville, KY. Electronic address: juan.guardiola@va.gov.

8Robley Rex Veterans Administration Medical Center, Louisville, KY; University of Louisville, School of Medicine, Department of Medicine, Division of Infectious Diseases, Louisville, KY. Electronic address: j.ramirez@louisville.edu.

Abstract

BACKGROUND:

It is unclear whether anteroposterior (AP) or posteroanterior with lateral (PA/Lat) chest radiographs are superior in the early detection of clinically relevant parapneumonic effusions (CR-PPEs). The objective of this study was to identify which technique is preferred for detection of PPEs using chest computed tomography (CCT) as a reference standard.

METHODS:

A secondary analysis of a pneumonia database was conducted to identify patients who received a CCT within 24 hours of presentation and also received AP or PA/Lat chest radiographs within 24 hours of CCT. Sensitivity and specificity were then calculated by comparing the radiographic diagnosis of PPEs of both types of radiographs compared with CCT by using the existing attending radiologist interpretation. Clinical relevance of effusions was determined by CCT effusion measurement of >2.5 cm or presence of loculation.

RESULTS:

There was a statistically significant difference between the sensitivity of AP (67.3%) and PA/Lat (83.9%) chest radiography for the initial detection of CR-PPE. Of 16 CR-PPEs initially missed by AP radiography, 7 either required drainage initially or developed empyema within 30 days, whereas no complicated PPE or empyema was found in those missed by PA/Lat radiography.

CONCLUSIONS:

PA/Lat chest radiography should be the initial imaging of choice in pneumonia patients for detection of PPEs because it appears to be statistically superior to AP chest radiography.

Published by Elsevier Inc.

PMID: 27793503 [PubMed - in process]