Avoiding Circulatory Complications During Endotracheal Intubation and Initiation of Positive Pressure Ventilation

Background: In many hospitals, emergency physicians commonly initiate invasive positive-pressure ventilation. Objectives: To review common patient- and ventilator-related factors that can promote hemodynamic instability during and after endotracheal intubation. Discussion: Venous return is proportional to mean systemic pressure (Pms) minus right atrial pressure (Pra). Endotracheal intubation with positive-pressure ventilation often reduces Pms while always increasing Pra, so venous return inevitably decreases, resulting in hypotension in almost one-third of patients. This article reviews the pathophysiology of respiratory failure, the basic circulatory physiology associated with endotracheal intubation, and methods that may be helpful to reduce the frequency of intubation-related hypotension. Conclusion: Although unproven, preventive measures taken before, during, and after endotracheal intubation are likely to minimize the frequency, magnitude, and duration of intubation-related hypotension.