Now we see the great relative proportion of all this optional equipment even in older infants. Let’s calculate the volume of this apparatus: cleft_repair_deadspace <-ĭeadspace_equipment_ml(humidifier = 'infant', E.g., for a cleft palate repair in an infant, a flexible extension is often used, in addition to a (hopefully) pediatric in-line humidifier. The volume of breathing circuit equipment is more important the smaller the patient. Ylab = 'Error in tidal volume delivery as fraction of delivered') Mutate(error_fraction = insp_tube_vol_diff / tidal_volume) The error is based on a machine check with fully collapsed tubing, and ventilation with fully extended tubing. The following plot shows the fractional error in tidal volume delivery in small patients.

This shows why a compliance test is essential before a neonatal anesthesia case, and why the tubing should not be extended or contracted after this test. The following chart shows the effect of this difference on deadspace fraction in neonatal ventilation.

Wasey October 1, 2017įully extending the primary concertina tubing of a breathing circuit increases compliance: the rigidity of the tubing itself falls, and there is more air in it.

Effect of breathing circuit compliance and dead-space on neonatal ventilation Jack O.

Dead space ventilation in old age