Study objectives: Because efforts to secure adequate
arterial oxygenation during cardiac resuscitation are more important
than efforts to promote CO2 elimination, we investigated
whether continuous transtracheal oxygenation (TTO) could represent a
potentially simpler alternative to conventional positive-pressure
ventilation with 100% O2 through an endotracheal
Design: Controlled and randomized.
Setting: Animal laboratory.
Thirty male Sprague-Dawley rats.
technique for TTO was initially developed and tested in five rats. A
model of ventricular fibrillation (VF) was then used to compare the
effects of TTO (n = 5) with the effects of O2 delivery
through an endotracheal tube as part of positive-pressure ventilation
(n = 5) or through a mask without additional airway intervention
(n = 5). VF was induced and left untreated for 4 min, after which
chest compression and one of the three oxygenation interventions was
started. Defibrillation was attempted after 6 min of chest compression.
In a subsequent series, defibrillation was attempted after 10 min of
chest compression in rats treated with either TTO (n = 5) or
endotracheal intubation (ET; n = 5).
results: TTO and ET secured adequate arterial
Po2 during chest compression (213 ± 77 mm Hg
and 154 ± 36 mm Hg; not significant), whereas the mask yielded an
arterial Po2 of only 49 ± 38 mm Hg
(p < 0.05). Each rat treated with TTO or ET was successfully
resuscitated and survived the postresuscitation interval, but none of
the rats treated with the mask survived. TTO maintained its efficacy
after increased duration of chest compression.
Conclusion: TTO was as effective as conventional
positive-pressure ventilation with 100% O2 for securing
oxygenation, resuscitation, and short-term survival and more effective
than O2 delivered through a mask.