title: Unexpected death of a ventilator-dependent amyotrophic lateral sclerosis patient.
abstract: BACKGROUND
  Amyotrophic lateral sclerosis (ALS) is a fatal, progressive, neurodegenerative disease and most patients affected die of respiratory compromise and/or pneumonia within 2-3 years of diagnosis. As ALS progresses, ventilator assistance is required. In the end stages of the disease, patients suffer from respiratory failure and may become ventilator-dependent. Deaths due to malfunction of mechanical ventilators are reported but there are very few forensic autopsy records. We report the case of a 69-year-old ALS female ventilator-dependent, trachostomised patient who was found dead by her husband, with the ventilator in "stand-by" mode.
  
  
  METHODS
  A forensic autopsy was performed. Samples of internal organs were taken for histological and toxicological examination. The ventilator internal memory was also analysed and tested in order to find possible malfunction.
  
  
  RESULTS
  Gross examination did not reveal any sign of trauma but showed brain and lung congestion. Pulmonary histological examination revealed thickening of peribronchial interstitial space, alveolar over-distension, break of inter-alveolar walls and diffuse alveolar haemorrhages. Focal microhemorrhages were also detected in other organs. Analysis of the ventilator internal memory showed that during the night of death, there had been several voltage drops. Specific tests revealed malfunction of the internal battery which was unable to provide the necessary voltage, as a consequence the ventilator switched off, stopping ventilation. Battery malfunction reduced the volume of the ventilator alarm, which was not heard by the caregiver.
  
  
  CONCLUSIONS
  Histological pattern, with acute pulmonary emphysema and focal polivisceral haemorrhages, is strongly suggestive of a death due to "acute" asphyxia. The authors also discuss the need for strict supervision and follow up of these ventilatory dependent patients and their devices.
authors.affiliation: Legal Medicine-Neuroscience Department, University of Pisa, Pisa, Italy.
authors.forename: M
authors.initials: M
authors.lastname: di Paolo
authors.forename: L
authors.initials: L
authors.lastname: Evangelisti
authors.forename: N
authors.initials: N
authors.lastname: Ambrosino
mesh_terms: D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000628:therapy*; D002423:Cause of Death; D004868:Equipment Failure; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D008168:Lung / Q000473:pathology; D012121:Respiration, Artificial / Q000295:instrumentation*
keywords: Acute respiratory failure; Amyotrophic lateral sclerosis; Esclerose lateral amiotrófica; Home mechanical ventilation; Insuficiência respiratória aguda; Ventilação mecânica doméstica