Noninvasive mechanical ventilation of mice by using a balloon-tipped cannula

Cardiovascular research in mouse models can lead to respiratory insufficiency with the need for temporary mechanical ventilation to reduce mortality. We developed a noninvasive method for brief ventilation in which a balloon-tipped cannula is inserted into the oral cavity of the mouse. The rubber balloon is constructed in such a way that it becomes inflated when the pressure in the tube rises. We tested the cannula in ten C57BL/6J mice which underwent mechanical ventilation by a membrane-pump-driven ventilator. Results of blood gas analyses in the ten cannulated animals were in the normal range after 1 h of mechanical ventilation and did not differ significantly from those of anesthetized and spontaneously breathing mice (n = 5) and mice mechanically ventilated via tracheal intubation (n = 5). Noninvasive mechanical ventilation by using the balloon-tipped cannula is a useful method which is quick and easy to manipulate.