383 The Effect of Display Size on Ultrasound Interpretation

Abstract

HAPE) by quantitative assessment of development of interstitial edema (as B-lines) in a healthy patient population at altitude.Methods: This was a cross-sectional, prospective study evaluating the development of pulmonary edema in healthy patients over a 96-hour period while at altitude of approximately 9,000 feet above sea level. A pulmonary exam consisting of four lung fields: bilateral lung apices (anterior/midclavicular at 3rd intercostal space) and bases (posterior axillary line at the 5th intercostal space) was performed by emergency physicians in four episodic 24 hour intervals.Results: 48 patients were enrolled into the study. Overall, there was a statistically significant positive shift in B-line distribution from Day 1 to Day 3, with a negative shift in B-line distribution from Day 3 to Day 4. The shift was observed in both the lung apex and base (P<0.001 & P¼0.004), respectively. The effect of participant age was also studied in a subgroup analysis. Both younger (less than 45 years old) and older (greater than 45 years old) populations had similar increases in B-line development within the first 3 days at altitude. However, the younger age group had a decrease in Blines from Day 3 to Day 4 while the older age group continued to have a positive increase in B-lines.Conclusion: Our data indicates that POCUS can be used to document interstitial edema in patients at altitude in a variety of age groups. POCUS may be an used to detect patients at risk for developing HAPE.