title: [Detection of venous air embolism and patent foramen ovale in neurosurgery patients in sitting position].
abstract: BACKGROUND
  Early detection of venous air embolism (VAE) during neurosurgical procedures in sitting position decreases the severity of its complications.
  
  
  OBJECTIVE
  our aim was to analyse the detection of VAE and its impact on patients operated in a sitting position, verify air aspiration through a central venous catheter and assess the feasibility of the routine use of transcranial Doppler (TCD) for intraoperative diagnosis of patent foramen ovale (PFO).
  
  
  METHODS
  We performed a prospective study of consecutive neurosurgical procedures performed in the sitting position for 5 years. Precordial Doppler and end-tidal carbon dioxide were the diagnostic methods for VAE. PFO was explored by TCD after anaesthetic induction.
  
  
  RESULTS
  136 patients were operated in the sitting position, 93 craniotomies and 43 cervical spine procedures. Twenty-two patients (16.2%) were diagnosed with VAE (21.5% of craniotomies and 4.7% of spinal surgeries; p=.013). In 59% of cases, air was aspirated through the central venous catheter. There was haemodynamic involvement in 3 patients, impaired oxygenation in 4 and clinically relevant pneumocephalus in 5 of them. Two patients (1.4%) were diagnosed with PFO, but did not present episodes of VAE or paradoxical air embolism.
  
  
  CONCLUSIONS
  The series analysed confirmed a higher incidence of VAE in craniotomies than in cervical spine surgery in a sitting position. We were able to aspirate air through the central venous catheter in more than half the cases. No patients suffered critical intraoperative complications following our approach. The low incidence of PFO detected with TCD will imply a modification of our protocol performed on anaesthetised patients.
authors.affiliation: Servicio de Anestesiología, Reanimación y Terapéutica del Dolor, Hospital Clínic de Barcelona, Barcelona, España.
authors.forename: Adriana
authors.initials: A
authors.lastname: Hervías
authors.affiliation: Servicio de Anestesiología, Reanimación y Terapéutica del Dolor, Hospital Clínic de Barcelona, Barcelona, España.
authors.forename: Ricard
authors.initials: R
authors.lastname: Valero
authors.affiliation: Servicio de Anestesiología, Reanimación y Terapéutica del Dolor, Hospital Clínic de Barcelona, Barcelona, España.
authors.forename: Paola
authors.initials: P
authors.lastname: Hurtado
authors.affiliation: Servicio de Anestesiología, Reanimación y Terapéutica del Dolor, Hospital Clínic de Barcelona, Barcelona, España.
authors.forename: Isabel
authors.initials: I
authors.lastname: Gracia
authors.affiliation: Servicio de Anestesiología, Reanimación y Terapéutica del Dolor, Hospital Clínic de Barcelona, Barcelona, España.
authors.forename: Laura
authors.initials: L
authors.lastname: Perelló
authors.affiliation: Servicio de Anestesiología, Reanimación y Terapéutica del Dolor, Hospital Clínic de Barcelona, Barcelona, España.
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Tercero
authors.affiliation: Servicio de Neurocirugía, Hospital Clínic de Barcelona, Barcelona, España.
authors.forename: José Juan
authors.initials: JJ
authors.lastname: González
authors.affiliation: Servicio de Anestesiología, Reanimación y Terapéutica del Dolor, Hospital Clínic de Barcelona, Barcelona, España. Electronic address: fabregas@clinic.ub.es.
authors.forename: Neus
authors.initials: N
authors.lastname: Fàbregas
mesh_terms: D000328:Adult; D004618:Embolism, Air / Q000175:diagnosis* / Q000209:etiology*; D005260:Female; D054092:Foramen Ovale, Patent / Q000150:complications*; D006801:Humans; D007430:Intraoperative Care / Q000379:methods*; D007431:Intraoperative Complications / Q000175:diagnosis* / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods; D056888:Patient Positioning; D011446:Prospective Studies
keywords: Cirugía de fosa posterior; Embolismo aéreo venoso; Foramen oval permeable; Neumoencéfalo; Neurocirugía; Neurosurgery; Patent foramen ovale; Pneumocephalus; Posición de sedestación; Posterior fossa surgery; Sitting position; Venous air embolism