Removing meconium from infant tracheae. What works best?

R. C. Bent, T. E. Wiswell and A. Chang
Uniformed Services University of the Sciences, Bethesda, Md.

OBJECTIVE--At least nine mechanical devices are available for suctioning the tracheae of meconium-stained newborns. To our knowledge, the efficacy of these devices, as well as various suction pressures and patterns, has not been previously compared. We performed this investigation to assess these variables. DESIGN--Fourteen suction techniques (combinations of device, suction pressure, and suction intermittency) were evaluated sequentially in the trachea of each of 14 in vitro newborn piglets (1 to 4 days old); the order was randomized using a Latin square design. We chose three devices to compare: a meconium aspirator (Neotech Products Inc, Chatsworth, Calif), a hand pump (Res-Q-Vac, Repromed Systems Inc, New York, NY), and a 10F suction catheter (Superior Healthcare Group Inc, Cumberland, RI). Both the meconium aspirator and the hand pump were used with a 3.0-mm endotracheal tube. INTERVENTION--We instilled 0.8 mL of a homogeneous mixture of human meconium and saline (44 g of meconium per 100 mL of saline) in the trachea before applying each suction technique. The meconium aspirator and the suction catheter were each evaluated at three different vacuum pressures, -40, -80, and -150 mm Hg, using both continuous and interrupted suction. The hand pump was evaluated with one and two activations (one activation generates -100 cm H2O, according to the manufacturer). MEASUREMENTS AND RESULTS--The percentage of instilled meconium recovered was consistently greatest (P less than .001) with the meconium aspirator (mean, 88.9% at -150 mm Hg, 84.9% at -80 mm Hg, and 73.5% at -40 mm Hg), intermediate with the catheter (mean, 81.0% at -150 mm Hg, 73.2% at -80 mm Hg, and 67.5% at -40 mm Hg), and least for the hand pump (mean, 67.9% with one activation and 72.6% with two activations). Recovery was better with continuous suction (P = .02) and increasing pressure (P less than .001). CONCLUSIONS--Among the techniques compared, the meconium aspirator at -150 mm Hg, using continuous suction, performed best in this model. It is unknown, however, to what extent the tracheal mucosa may be affected by this degree of negative pressure.