Extending the preoxygenation period from 4 to 8 mins in critically ill patients undergoing emergency intubation*
Crit Care Med. 2008 Nov 28;
Authors: Mort TC, Waberski BH, Clive J
OBJECTIVE:: To determine the effectiveness of increasing the preoxygenation period with 100% oxygen in the critically ill patient from 4 to 8 mins in preparation for emergency tracheal intubation. DESIGN:: Nonrandomized, controlled trial. SETTING:: Large, level one trauma center, tertiary care intensive care unit. PATIENTS:: Critically ill patients failing noninvasive respiratory support techniques who required tracheal intubation followed by mechanical ventilation. INTERVENTIONS:: A baseline arterial blood gas was obtained on noninvasive passive therapy and at 4, 6, and 8 mins of active preoxygenation efforts with 100% oxygen therapy with a noncollapsing resuscitator bag and mask. Best effort to achieve a tight fitting mask seal was pursued coupled with other mask ventilation maneuvers to optimize noninvasive oxygenation and ventilation. MEASUREMENTS AND MAIN RESULTS:: Thirty-four patients consecutively intubated by the author during the 7-month study period were studied. The baseline Pao2 (mean +/- sd) with concurrent noninvasive support was 61.9 +/- 14.6 mm Hg (range: 44-109 mm Hg) and increased a mean of 22 mm Hg to 83.8 +/- 51.5 mm Hg after 4 mins of preoxygenation (p < 0.01). Continued preoxygenation efforts (6 mins) increased the Pao2 to 88.2 mm Hg +/- 48.5 and after 8 mins to 92.7 mm Hg +/- 55.2. At the 8-min mark, 5 of 34 patients achieved >10% increase in their Pao2 and only two patients increased their 4-min Pao2 by >/=50 mm Hg after the additional 4 mins of preoxygenation. One quarter of the patients experienced a reduction in their Pao2 from the 4 to the 8-min time period. Nearly, 50% of the patients met the criteria for desaturation during the intubation procedure. CONCLUSIONS:: Extending the preoxygenation period from the customary 4 mins to either 6 or 8 min seems to be marginally effective in the majority of patient suffering from cardiopulmonary deterioration and such an extension may jeopardize oxygenation efforts in some patients.
PMID: 19050620 [PubMed - as supplied by publisher]