Effects of tidal volume, ventilatory frequency, and oxygen insufflation flow on the fraction of inspired oxygen in cadaveric horse heads attached to a lung model

Abstract

In the study model, measured fraction of inspired oxygen varied with ventilatory pattern as well as oxygen insufflation rate. Clinically, this information could be beneficial for interpretation of data regarding arterial blood gases and hemoglobin saturation and in making appropriate oxygen insufflation decisions for anesthetized horses that are breathing room air.

Butorphanol with oxygen insufflation corrects etorphine-induced hypoxaemia in chemically immobilized white rhinoceros (Ceratotherium simum)

“…Similarly, in horses under general anaesthesia where airway integrity is compromised by the weight of abdominal organs, increased intrapulmonary shunting occurs as a result of atelectasis when breathing high F i O 2 (>0.8) compared to a lower F i O 2 (0.21-0.3) [ 21 , 22 ]. It has also been demonstrated in horses receiving supplemental oxygen that lower minute ventilation will result in higher F i O 2 [ 23 ]. Thus we propose that the rhinoceros receiving oxygen supplementation in our study had a high F i O 2 together with narrowed or compressed airways as a result of pressure from abdominal organs and poor ventilation.…”

Effects of oxygen insufflation rate, respiratory rate, and tidal volume on fraction of inspired oxygen in cadaveric canine heads attached to a lung model

“…[1][2][3][4] Increasing the flow rate during nasal oxygen delivery has been shown to increase the FIO 2 in various species, including dogs. [1][2][3][4]9 Because control of tidal volume and respiratory rate is not possible in awake clinical patients, previous studies have not determined how these factors may affect FIO 2 . Additionally, air-containing space in a dog' s head may act as a reservoir for insufflated oxygen during the expiratory pause between breaths.…”

“…There are various methods to provide supplemental oxygen, including delivery via a nasal insufflation catheter, flow-by, face mask, use of an oxygen chamber, and transtracheal administration. [1][2][3][4][5][6][7][8][9] Delivery of oxygen with flow-by and face mask techniques can be simple, but these are not always well tolerated and usually require technical support to hold the oxygen line or face mask close to the nose of the patient and create an increased oxygen concentration in that area. 5 Commercially available oxygen chambers are sealed compartments with mechanisms to provide oxygen supplementation, eliminate exhaled CO 2 , and regulate humidity and ambient temperature.…”