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Correspondence  |   June 2000
Preoxygenation: Comparison of Maximal Breathing and Tidal Volume Techniques
Author Notes
  • Professor
  • Department of Anesthesiology
  • University of California San Diego
  • San Diego, California
  • jbenumof@ucsd.edu
Article Information
Correspondence
Correspondence   |   June 2000
Preoxygenation: Comparison of Maximal Breathing and Tidal Volume Techniques
Anesthesiology 6 2000, Vol.92, 1845. doi:
Anesthesiology 6 2000, Vol.92, 1845. doi:
In Reply:
—Drs. Morrison and Videira make the valid point that pediatric patients desaturate faster than adults and that preoxygenation is especially indicated in several types of pediatric patients. In fact, I have previously reported complete apnea-oxyhemoglobin desaturation curves for various humans using computer modeling 1 and have showed that a 10-kg pediatric patient will desaturate twice as fast as a 70-kg adult. Rather than offer a convoluted explanation as to how the words “obvious exclusion examples” were chosen, I agree the phrase is too broad and that Dr. Morrison provides examples of two patients who deserve to be preoxygenated.
Dr. Salem et al.  are probably correct with their hypothesis that Baraka et al.  actually studied 10 to 12 deep breaths in 75 to 90 s rather than eight deep breaths in 60 s. In ongoing studies I have tried to repeat the Baraka et al.  methodology. Even with extensive preoxygenation coaching of the patients, I have found that the preoxygenation process is always extended by at least 2 breaths beyond the intended period. In fact, if one wants to study eight deep breaths in 60 s, then the rapid sequence induction must be begun on the inspiratory limb of the sixth breath. I agree with the Salem et al.  comment regarding the effect of an extended period of hyperventilation on shifting the oxyhemoglobin curve further to the left.
In summary, I thank Drs. Morrison, Videira, and Salem for their thoughtful insights.
References
Benumof JL, Dagg R, Benumof R: Critical hemoglobin desaturation will occur before return to an unparalyzed state following 1 mg/kg intravenous succinylcholine. A nesthesiology 1997; 87:979–82Benumof, JL Dagg, R Benumof, R