title: High-frequency jet ventilation shortened the duration of gas embolization during laparoscopic liver resection in a porcine model.
abstract: BACKGROUND
  Positive pressure mechanical ventilation causes rhythmic changes in thoracic pressure and central blood flow. If entrainment occurs, it could be easier for carbon dioxide to enter through a wounded vein during laparoscopic liver lobe resection (LLR). High-frequency jet ventilation (HFJV) is a ventilating method that does not cause pronounced pressure or blood flow changes. This study aimed to investigate whether HFJV could influence the frequency, severity, or duration of gas embolism (GE) during LLR.
  
  
  METHODS
  Twenty-four anaesthetized piglets underwent lobe resection and were randomly assigned to either normal frequency ventilation (NFV) or HFJV (n=12 per group). During resection, a standardized injury to the left hepatic vein was created to increase the risk of GE. Haemodynamic and respiratory variables were monitored. Online blood gas monitoring and transoesophageal echocardiography were used. GE occurrence and severity were graded as 0 (none), 1 (minor), or 2 (major), depending on the echocardiography results.
  
  
  RESULTS
  GE duration was shorter in the HFJV group (P=0.008). However, no differences were found between the two groups in the frequency or severity of embolism. Incidence of Grade 2 embolism was less than that found in previous studies and physiological responses to embolism were variable.
  
  
  CONCLUSIONS
  HFJV shortened the mean duration of GE during LLR and was a feasible ventilation method during the procedure. Individual physiological responses to GE were unpredictable.
authors.affiliation: Department of Surgical Sciences, Anaesthesiology and Intensive Care, Uppsala University, Uppsala SE-75185, Sweden diddi.fors@akademiska.se.
authors.forename: D
authors.initials: D
authors.lastname: Fors
authors.affiliation: Department of Surgical Sciences, Surgery, Uppsala University, Uppsala SE-75185, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Eiriksson
authors.affiliation: Department of Gastrointestinal Surgery, Oslo University Hospital, Oslo, Norway.
authors.forename: A
authors.initials: A
authors.lastname: Waage
authors.affiliation: Department of Surgical Sciences, Surgery, Uppsala University, Uppsala SE-75185, Sweden.
authors.forename: D
authors.initials: D
authors.lastname: Arvidsson
authors.affiliation: Department of Surgical Sciences, Anaesthesiology and Intensive Care, Uppsala University, Uppsala SE-75185, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Rubertsson
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D017548:Echocardiography, Transesophageal / Q000379:methods; D004618:Embolism, Air / Q000209:etiology / Q000517:prevention & control*; D005260:Female; D006498:Hepatectomy / Q000009:adverse effects / Q000379:methods*; D006611:High-Frequency Jet Ventilation / Q000379:methods*; D010535:Laparoscopy / Q000009:adverse effects / Q000379:methods*; D008099:Liver / Q000601:surgery; D008297:Male; D011659:Pulmonary Gas Exchange / Q000502:physiology; D012720:Severity of Illness Index; D013552:Swine; D013997:Time Factors
keywords: animal model; gas embolism; high frequency jet ventilation; laparoscopic; liver resection