Medical College of Wisconsin
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Hemodynamic changes during endotracheal suctioning are mediated by increased autonomic activity. Pediatr Res 1993 Jun;33(6):649-52



Pubmed ID




Scopus ID

2-s2.0-0027280731   19 Citations


Endotracheal suctioning of intubated infants produces profound changes in cardiovascular and cerebral hemodynamics, but the mechanisms regulating these changes are not fully understood. To determine the role of the autonomic nervous system in regulating these physiologic changes, we investigated the effects of endotracheal suctioning on heart rate (HR), mean arterial blood pressure (MABP), and renal sympathetic nerve activity (RSNA) in nine ventilated newborn lambs. In the first part of the study (n = 6), ventilation was interrupted for suctioning. With suctioning (15 s), HR decreased by 39 +/- 6% (p < 0.05), whereas MABP and RSNA increased significantly (p < 0.05) by 36 +/- 5% and 68 +/- 8%, respectively. These changes were significantly (p < 0.05) larger than changes observed during disconnection from the ventilator (15 s) without suctioning. Administration of atropine (0.02 mg/kg) blocked the HR response to suctioning without altering MABP or RSNA changes. After bilateral vagotomy, suctioning produced no changes in any parameter. When a closed tracheal suction system was used and ventilation was maintained, suctioning again resulted in significant (p < 0.05) increases in MABP (+10 +/- 3%) and RSNA (+34 +/- 5%) and a decrease in HR (-15 +/- 4%). These data suggest that suctioning stimulates sympathoexcitatory receptors localized in large airways whose afferent fibers course within the vagus, resulting in increased sympathetic activity, which induces peripheral vasoconstriction and elevates MABP. In contrast, the HR response appears to be mediated by increased parasympathetic activity as this is abolished by atropine.

Author List

Segar JL, Merrill DC, Chapleau MW, Robillard JE


Jeffrey L. Segar MD Professor in the Pediatrics department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals, Newborn
Autonomic Nervous System
Blood Pressure
Heart Rate
Vagus Nerve
jenkins-FCD Prod-478 d1509cf07a111124a2d122fd3df854cc0b993c00