Evaluation of respiratory function during Reeves stretcher use

We were aware of a small number of cases in our EMS system where patients in respiratory distress had a worsening of their condition after being removed from the home on a Reeves stretcher (RS). We sought to determine if this prehospital lifting device causes additional respiratory effort used in normal subjects by describing changes in heart rate, pulse oximetry, tidal volume, minute ventilation, and respiratory rate.

Forty-nine subjects were entered into this study. Data were collected while the subject was supine on the floor in the RS and once while suspended over the floor in the device. A randomized crossover design was used. Ten subjects were excluded because of inadvertent omission of a nose plug during spirometry. Data points were recorded in the final minute of a 3-minute exposure. Three minutes was chosen to simulate a prehospital transport time from the scene to the ambulance. Minute ventilation, tidal volume, heart rate, pulse oximetry, and respiratory rate were recorded for each subject during each phase. Subjects were also asked to rate the difficulty of breathing using the modified Borg scale.

Data were obtained for 39 subjects. The mean respiratory rate while suspended was 9.9 +/- 3.0 breaths per minute compared to 9.1 +/- 2.5 breaths per minutes supine on the floor (p = 0.007). The mean minute ventilation while suspended in a RS was 8.17 +/- 3.25 L/min versus 7.37 +/- 2.37 while lying flat (p = 0.03). There was no difference in tidal volume, heart rate, pulse oximetry, or subjective modified Borg scale ratings.

Subjects suspended in a RS for 3 minutes had statistically higher respiratory rates and minute ventilation than the same subjects lying flat. Although these modest changes are clinically insignificant in normal subjects, they could present a significant challenge to subjects in respiratory distress.