Pressure-controlled ventilation is superior to volume-controlled ventilation with a laryngeal mask airway in children.
BACKGROUND
This prospective, randomized, crossover study had two purposes: first, to determine whether pressure-controlled ventilation (PCV) is safer than volume-controlled ventilation (VCV) by preventing gastric insufflation in children ventilated through an laryngeal mask airway (LMA); second, to assess whether the measurement of LMA leak pressure (P(leak)) is useful for preventing leakage during positive pressure ventilation (PPV).


METHODS
Forty-one, 2 to 15-year-old children underwent general anesthesia with an LMA. The expiratory valve was set at 30 cmH(2)O and P(leak) was measured using constant gas flow. Children were randomly ventilated using PCV or VCV for 5 min in order to reach a P(ET)CO(2) not exceeding 45 mm Hg, and then they were ventilated with the alternative mode. If the target P(ET)CO(2) could not be obtained in one mode, we switched to the other. If both modes failed, children were intubated. Tidal volumes, P(ET)CO(2) and airway pressures were noted and compared between modes. Gastric insufflation was checked by epigastric auscultation.


RESULTS
PCV provided more efficient ventilation than VCV, as targeted P(ET)CO(2) was obtained without gastric insufflation using PCV in all cases except one, whereas VCV failed in three cases. No gastric insufflation occurred when ventilating below peak.


CONCLUSIONS
These findings suggest that in the age group studied, PCV is more efficient than VCV for controlled ventilation with a laryngeal mask. Gastric insufflation did not occur with this mode.
Bordes
M
M
Pellegrin Children's Hospital, Bordeaux 2 University, Bordeaux, France. Maryline.bordes@chu-bordeaux.fr
Semjen
F
F
Degryse
C
C
Bourgain
J L
JL
Cros
A M
AM
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D018592:Cross-Over Studies; D006801:Humans; D017214:Laryngeal Masks; D012123:Pulmonary Ventilation; D012121:Respiration, Artificial / Q000009:adverse effects / Q000379:methods*