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The comparison of various ventilation modes and the association of risk factors with CO2 retention during suspension laryngoscopy


  • The authors have no funding, financial relationships, or conflicts of interest to disclose.



To compare the effectiveness of various ventilation modes during suspension laryngoscopy and to investigate risk factors associated with CO2 retention in high-frequency jet ventilation (HFJV).

Study Design:

Part I: Randomized controlled study; Part II: Outcomes research.


In Part I, saturation of peripheral oxygen, partial pressure of carbon dioxide (PaCO2), and pH were recorded in different ventilation modes in 60 patients. All subjects were randomly divided into four groups. Three groups received different jet ventilations through a catheter inserted transnasally, and one group had tracheal intubation and received intermittent positive pressure ventilation. In Part II, 59 patients received jet ventilation with a fixed rate; CO2 retention and its potential risk factors were analyzed. Data were collected at the following time points: preinduction (T0), anesthesia induction (T1), laryngoscopic operation (T2), 10 minutes after the initiation of ventilation (T3), extubation (T4), and 10 minutes after extubation (T5).


In Part I, mean arterial pressure (MAP) increased and heart rate decreased significantly during T2 (P < .01), MAP and heart rate increased significantly during T4 (P < .01), and PaCO2 increased and pH decreased significantly in T3 and T5 (P < .01) in all four groups. Using logistic regression analysis of results from Part II, it was determined that in males, the combination of higher weight, lower height, and body mass index values greater than 25.224 was closely associated with CO2 retention.


During suspension laryngoscopy surgery, HFJV at 60 beats per minute through a thin transnasal catheter provides adequate ventilation as well as an excellent surgical view. A body mass index of more than 25.224 is the main risk factor for CO2 retention. Laryngoscope, 2011