Literature Review: Lung Sound Interpretation

      Williams B, Boyle M, O'Meara P. Can undergraduate paramedic students accurately identify lung sounds? Emerg Med J 26(8): 580-2, Aug 2009.

Abstract

   Abstract--The accurate identification of lung sounds during chest auscultation is a skill commonly used by healthcare clinicians, including paramedics, when assessing a patient's respiratory status. It is a necessary skill, as it enables confirmation of a patient's respiratory condition and guides the paramedic to a provisional diagnosis and the implementation of appropriate management. The object of this study was to identify if undergraduate paramedic students from two Australian universities were able to interpret a variety of lung sounds accurately.

   Methods--A prospective single-blinded observational study requiring 96 undergraduate paramedic students from two Australian universities to estimate the lung sounds of six audio files.

   Results--The findings demonstrated variable accuracy in lung sound interpretation of the six audio files. The lung sound that contained a wheeze was most accurately interpreted, whereas coarse crackles were the least accurately interpreted. Monash University undergraduate paramedic students displayed similar lung sound interpretations to Charles Sturt University undergraduate paramedic students.

   Conclusion--In this study undergraduate paramedic students from two Australian universities were found to be inaccurate at interpreting a variety of common lung sounds. The study has highlighted that a greater emphasis needs to be given to lung sound interpretation in undergraduate paramedic education programs.

Comment

   The accurate interpretation of lung sounds is an essential part of assessment and treatment for many conditions. Distinguishing crackles from wheezes can help differentiate between COPD and CHF. Diminished breath sounds can make one suspicious of a pneumothorax, hemothorax or right main-stem (or even esophageal) intubation. Coarse crackles are different than fine crackles.

   But the prehospital setting presents many challenges that limit the accuracy of auscultation. Scenes are often noisy and chaotic, patient contact time is short, histories are incomplete or inaccurate, and the equipment (i.e., stethoscopes) may not be the best quality.

   This study raises the possibility that one more challenge may be insufficient primary paramedic education. Here, paramedic students had difficulty with lung sounds even without distraction and ambient noise. If one adds in the special scene challenges, this has the potential to limit a paramedic's ability to properly assess patients--which can lead to incorrect and even dangerous treatments.

   EMS systems may want to evaluate this in their own education systems and improve training or continuing education as needed.

   Angelo Salvucci, Jr., MD, FACEP, is an emergency physician and medical director for the Santa Barbara County and Ventura County (CA) EMS agencies.