The Science Journal of the American Association for Respiratory Care

2012 OPEN FORUM Abstracts


Lauren Gilseth, Christopher Marti, Emelin Tan, Steve Holets, Richard Hinds, Peter Gay; Mayo Clinic, Rochester, MN

BACKGROUND: A literature search of articles from 1999 to 2011 revealed that the accuracy of height, weight and ideal body weight (IBW) estimates by hospital clinicians are unreliable. Results also reveal that there is a tendency for clinicians to overestimate height in patients with lower body habitus and underestimate height in patients with higher body habitus. OBJECTIVE: The study aims to determine if prehospital care providers* can accurately estimate heights of supine individuals to initiate appropriate tidal volume settings for mechanical ventilation, based on standard IBW calculations. HYPOTHESIS: We hypothesize that pre hospital care providers cannot accurately estimate the height of supine individuals. METHODS: Following IRB approval the study was introduced to participants (Respiratory Therapy students) and verbal consent obtained. Subjects were prohibited from communicating with peers throughout the study. All subjects took turns laying supine on the ground while observers recorded estimated heights on a provided spreadsheet. We limited observation time to less than 30 seconds to replicate time constraints in an emergent situation. Post-observation, subjects were measured supine to establish actual height. Subjects were deidentified and a concordance correlation coefficient test was performed using the statistical program MedCalc. RESULTS: Our results reveal that the sample could not estimate height accurately with a poor concordance correlation coefficient of 0.8037. However, further data analysis revealed that derived tidal volumes from estimated heights fell within 4-8ml/kg/IBW with 83% of calculations < 6ml/kg/IBW. CONCLUSION: We conclude that pre hospital care providers cannot accurately estimate the height of supine individuals. However, there appears to be a general ability to mechanically ventilate a patient within established safe limits. Our study was limited to a small sample and requires larger studies to validate our results. *Prehospital care providers refers to individuals who administer care prior to hospital admission e.g. military medics, EMT etc. Sponsored Research - None