Piglet Tracheal Epithelial Regeneration After Suctioning

Endotracheal suctioning (ETS) is the only method used to insure patency of the endotracheal tube in intubated newborn infants. Associated with this nursing procedure are iatrogenic complications that include hypoxemia, bradycardia and tracheal trauma. Negative pressure applied to remove accumulated secretions and debris also removes portions of the tracheal epithelium, resulting in alteration of the mucociliary transport system (MTS). Alteration in MTS results in accumulated secretions and debris in the endotracheal tube thereby compromising both oxygenation and ventilation. Trauma to the tracheal epithelium is known to result in tracheal stenosis and scaring. The use of positive expiratory end pressure (PEEP) has been postulated to decrease the degree of trauma associated with suctioning since the air currents help keep the catheter away from the epithelium. This study will answer two questions; does PEEP provide a protective mechanisms for the tracheal epithelium, and is the process of recovery different with suctioning with and without PEEP.

In this study, using an animal model, 98 subjects were divided into four groups. Each of these groups were further divided into 7 groups based upon the time that the tracheas would be harvested. The control group was not intubated or ventilated. The sham group was intubated and ventilated but received no endotracheal suctioning over a six hour time period. The third group was intubated, ventilated and received ETS once an hour for six hours using a catheter that maintains PEEP while the fourth groups was suctioned once an hour for six hours using a conventional suction catheter. The animals received physiologic monitoring to include oxygen saturation during the protocol. Tracheas were harvested from the animals at 0, 3, 7, 10, 14, 17, and 21 days post suctioning. Trachea sections were stained with H & E and examined under light microscopy for tracheal epithelial loss by cell type and depth using video image analysis. Data from tracheal sections were analyzed by groups and time to determine the degree of acute trauma to the epithelium and the process of epithelial regeneration. The control tracheas were determined by tracheal length and diameter. Percentage of cell loss by group and time frame was determined by ANOVA. Data analysis indicated that there were significant differences in tracheal epithelial loss between the groups and over time. Post hoc analysis demonstrated no significant difference between the control and sham group over time, nor between the ZEEP and PEEP group (p>.06), over time but highly significant differences (P.0001 control="" and="" sham="" groups="" the="" peep="" zeep="" groups.="" tracheal="" length="" diameter="" growth="" proceeded="" at="" same="" rate="" for="" all="" thus="" intubation="" ventilation="" suctioning="" although="" highly="" disruptive="" to="" mts="" did="" not="" affect="" growth.="" regeneration="" had="" begun="" with="" group="" by="" days="" but="" epithelium="" was="" rebuilt="" level="" of="" sham.="" implications="" military="" nurses="" are="" that="" there="" is="" evidence="" in="" an="" animal="" model="" ets="" no="" more="" traumatic="" than="" zeep.="" maintains="" airflow="" during="" ets.="">
Data from this study provided important information for the practicing nurse on suctioning with PEEP. Further insight was gained on understanding the process of tracheal epithelial regeneration.