title: The comparison of various ventilation modes and the association of risk factors with CO₂ retention during suspension laryngoscopy.
abstract: OBJECTIVE
  To compare the effectiveness of various ventilation modes during suspension laryngoscopy and to investigate risk factors associated with CO(2) retention in high-frequency jet ventilation (HFJV).
  
  
  METHODS
  Part I: Randomized controlled study; Part II: Outcomes research.
  
  
  METHODS
  In Part I, saturation of peripheral oxygen, partial pressure of carbon dioxide (PaCO(2) )(,) 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; CO(2) retention and its potential risk factors were analyzed. Data were collected at the following time points: preinduction (T(0) ), anesthesia induction (T(1) ), laryngoscopic operation (T(2) ), 10 minutes after the initiation of ventilation (T(3) ), extubation (T(4) ), and 10 minutes after extubation (T(5) ).
  
  
  RESULTS
  In Part I, mean arterial pressure (MAP) increased and heart rate decreased significantly during T(2) (P < .01), MAP and heart rate increased significantly during T(4) (P < .01), and PaCO(2) increased and pH decreased significantly in T(3) and T(5) (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 CO(2) retention.
  
  
  CONCLUSIONS
  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 CO(2) retention.
authors.affiliation: Department of Anesthesiology, The Eye, Ear, Nose, and Throat Hospital, Fudan University, Shanghai, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Tang
authors.forename: Shao-Qing
authors.initials: SQ
authors.lastname: Li
authors.forename: Lian-Hua
authors.initials: LH
authors.lastname: Chen
authors.forename: Chang-Hong
authors.initials: CH
authors.lastname: Miao
mesh_terms: D000328:Adult; D000368:Aged; D000768:Anesthesia, General; D015992:Body Mass Index; D002245:Carbon Dioxide / Q000097:blood*; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006611:High-Frequency Jet Ventilation; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006935:Hypercapnia / Q000209:etiology*; D007385:Intermittent Positive-Pressure Ventilation; D007431:Intraoperative Complications / Q000209:etiology*; D007442:Intubation, Intratracheal; D007828:Laryngoscopy / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D012307:Risk Factors; D055815:Young Adult
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen