Abstract 136: Lucas 2 ETCO2 Not Always Better than Feedback-Guided Manual CPR
High quality chest compressions is believed to be a major contribution to survival, and has been related to the level of end-tidal CO2 (ETCO2), a surrogate for induced flow. Automated CPR (A-CPR) devices in clinical use include the Autopulse™ (Zoll) and the LUCAS™ (PhysioControl).While A-CPR has been suggested to provide consistently “at least as good as” compressions, we noted cases with decreasing ETCO2 during LUCAS2 compressions, and initially anecdotally reinstituted manual CPR with QCPR feedback. We observed ETCO2 improvements thereafter.
Aim: Describe ETCO2 changes during LUCAS2 and manual in-hospital resuscitations in relationship to the cases. We sought patient-oriented common factors as root cause.
Method: Open, cohort, analysis of CPR cases with manual after automated CPR using Philips MRx and hospital data.
Results and discussion: Since Jan-2012, eight (of 26) CPR cases were analyzable with manual compressions after automated LUCAS2 chest compressions. Paired t-test showed significant improvement to a new ETCO2 steady state under manual CPR in all of these cases (p=.012, change range 0.4 - 6.9 kPa, 95% C.I. -3,92 - -0,68).
Rhythms: PEA(5), VF(2), ASYS(1) with ROSC in 5 cases. In six cases CT-thorax showed AP-diameters from 19 to 26,5 cm. Compression position ≤1 cm of “mid sternal line”. The ITD was used in all cases with ventilations at 8-16 min-1 unaltered under automated versus manual compressions. Force applied with manual compressions was 700 ± 119N. Resuscitations were in bed with backboards and estimated depths of ± 6 cm. No correlations (rhythm, chest size, medication) could be found in this small series as cause other than the extra force during manual compressions leading to increased, steady state, ETCO2. Even for proponents of A-CPR, it seems that falling ETCO2 during ongoing automated compressions, and in the absence of other identifiable causes, should lead to consideration of manual feedback controlled compressions, which may improve ETCO2.Conclusion: Altered force seems the factor, not case characteristics. Although A-CPR delivers constant quality compressions, feedback driven manual CPR allows user adjustments in force and depth. This should be considered in cases of automated CPR with persistent low or decreasing ETCO2 levels.
- © 2012 by American Heart Association, Inc.