How much lung ventilation is obtained with only chest-compression CPR?
The objective of this 14-pig study was designed to determine the amount of lung ventilation obtainable by only rhythmic chest compression (100/min, 100 lbs). Tidal volume (TV), dead space (DS), and respiration rate (R) were measured with normal breathing and with rhythmic chest compression during ventricular fibrillation. The ratio of TV/DS was calculated in both cases. For normal breathing the ratio was 2.54 +/- 0.68; for chest compression breathing the ratio was 0.80 +/- 0.07. Minute alveolar ventilation (TV - DS)R was computed for both cases. With spontaneous breathing, the minute alveolar volume was 5.48 +/- 2.1 l/min. With only chest-compression breathing, the alveolar ventilation was -1.49 +/- 0.64 l/min. The negative minute alveolar volume and fractional ratio reveals that TV was less than the dead space indicating that chest-compression alone does not ventilate the lungs.
Geddes
L A
LA
Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907-2032, USA. geddes@ecn.purdue.edu
Rundell
A
A
Otlewski
M
M
Pargett
M
M
D000818:Animals; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D008168:Lung / Q000502:physiology*; D012123:Pulmonary Ventilation / Q000502:physiology*; D015656:Respiratory Mechanics / Q000502:physiology*; D013552:Swine; D013990:Tidal Volume / Q000502:physiology*