Abstract P183: Physical Stress Does Not Increase Ventilation Rate during Resuscitation in a Manikin Model
BACKGROUND: Studies indicate that trained medical personnel often deliver manual ventilations at excessive rates while performing advanced cardiac life support (ACLS). Excessive ventilation rates may contribute to increased mortality among these patients. We seek to uncover if physical stress affects our perception of ventilation rate.
HYPOTHESIS: We hypothesized that physical stress would increase the ventilation rate during simulated cardiac arrest in a manikin model.
METHOD: Six persons at Laerdal Medical were asked to ventilate an intubated manikin (Laerdal ResuciAnne PC SkillReporting system) for three minutes under two different conditions. For the first condition the participants were asked to perform strenuous physical exercise (running up and down a stairway for several minutes) immediately prior to ventilating the manikin. For the second condition all participants were allowed to rest before performing ventilations. Participants had to deliver ventilations at what they felt were 10 ventilations per minute (vpm). No clock or other time keeping means were available. Heart rate and breathing rate of the participants were measured using ECG and trans-thoracic impedance signals from a defibrillator (Philips HeartStart MRx). Statistics are derived using the average rate values from each participant.
RESULTS: The participants did not ventilate faster after physical stress (Mean rate =7.00 vpm, SD =1.94) than during the condition at rest (Mean rate =7.14 vpm, SD =1.10; t(5) =−0.20, 95% CI of mean difference −1.83, 1.57; Cohen’s d =0.085; p =0.85). On the average, no participants ventilated faster than the recommended rate of 10–12 vpm during any condition. Both the participants’ heart rate and respiration rate were significantly different during the two conditions; mean (SD) heart rate 112 (10.7) vs. 82 (5.3) bpm (p=0.002), mean (SD) respiration rate 21.2 (5.98) vs. 14.5 (3.44) breaths per minute (p=0.010).
CONCLUSIONS: Ventilation rates do not seem to be elevated by physical stress of the provider. Causes of hyperventilation should be sought elsewhere, e.g. amongst mental stressors.