title: [Evaluation of amplified spontaneous pattern ventilation in postoperative patients. Comparison with pressure support].
abstract: OBJECTIVE
  Amplified spontaneous pattern (ASP) ventilation is a new method for giving partial support by reproducing, in an amplified manner, the patients' own spontaneous flow wave form, thereby optimizing patient adaptation to support.
  
  
  OBJECTIVE
  To study clinical use of ASP ventilation for the first time in terms of flow wave form, patient synchronization, ventilation pattern, work of breathing (WOB), and inspiratory effort by transpulmonary pressure (TPP) and to compare ASP and pressure support ventilation applied in a similar clinical setting.
  
  
  METHODS
  We studied 20 patients after heart surgery during weaning from controlled ventilation. Each patient was ventilated during 4 phases of 15 min each with two similar levels of support using ASP and PS applied successively and randomly. Maximum support (ASPmax and PSmax) was that which was set to give the same respiratory frequency (F) and tidal volume (VT) as that recorded during the earlier period of controlled ventilation. Half support (PEA1/2 and PS1/2) was set for half the aforementioned levels. At the end of each phase we obtained gas measurements and flow (V) curves and VT and pressure in airways and esophagus (Pes) to measure F, VT, the ratio of inspiratory to total time (TI/TTOT and TPP, as well as the VT/Pes loop with a mechanical ventilation monitor. The WOB was determined by measuring area under the curve (Campbell's method).
  
  
  RESULTS
  We observed no significant differences between the two modes, with similar levels of support, with regard to ventilation (PaCO2) or ventilatory pattern (F, VT, TI/TTOT). De-adaptation occurred, however, eight times with PS (25%) but never with ASP. WOB and TPP decreased with PS when level of support increased, whereas with ASP these variables were constant regardless of level of amplification within the normal range.
  
  
  CONCLUSIONS
  Adaptation to support is better with ASP than with PS during postoperative weaning and causes no significant respiratory work overload.
authors.affiliation: Servicio de Anestesiología y Reanimación, Hospital Clínico Universitario de Valencia.
authors.forename: A M
authors.initials: AM
authors.lastname: Sánchez de Merás
authors.forename: P
authors.initials: P
authors.lastname: Páiz
authors.forename: I
authors.initials: I
authors.lastname: Perpiñán
authors.forename: J
authors.initials: J
authors.lastname: García Polit
authors.forename: J
authors.initials: J
authors.lastname: Soliveres
authors.forename: G
authors.initials: G
authors.lastname: Aguilar
authors.forename: A
authors.initials: A
authors.lastname: Maruenda
authors.forename: F J
authors.initials: FJ
authors.lastname: Belda
mesh_terms: D000222:Adaptation, Physiological; D002245:Carbon Dioxide / Q000097:blood; D019918:Heart Valve Prosthesis Implantation; D006439:Hemodynamics; D006801:Humans; D009204:Myocardial Revascularization; D010100:Oxygen / Q000097:blood; D010313:Partial Pressure; D011182:Postoperative Care / Q000379:methods*; D011183:Postoperative Complications / Q000503:physiopathology / Q000628:therapy; D011446:Prospective Studies; D011659:Pulmonary Gas Exchange; D012123:Pulmonary Ventilation; D012120:Respiration Disorders / Q000503:physiopathology / Q000628:therapy; D012129:Respiratory Function Tests; D012132:Respiratory Muscles / Q000503:physiopathology; D012138:Respiratory Therapy / Q000379:methods*; D015300:Ventilator Weaning; D014939:Work of Breathing
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen
vernacular_title: Evaluación de la ventilación con patrón espontáneo amplificado en pacientes postoperados. Comparación con la presión de soporte.