title: Pilot study of a protocol to administer inhaled nitric oxide to treat severe acute submassive pulmonary embolism.
abstract: OBJECTIVE
  Inhaled nitric oxide has been reported to benefit patients with acute pulmonary embolism (PE). To date, all published literature has derived from case reports or case series conducted without a structured protocol. Here we report the results of a phase I trial with a predefined clinical protocol to treat patients with CT-demonstrated, submassive PE and moderate to severe dyspnoea.
  
  
  METHODS
  Patients were recruited from the emergency department of an academic teaching hospital. Informed consent and the entire treatment protocol was administered by a study physician. Nitric oxide was administered using a commercial device (Inovent) and a custom-made non-rebreathing face mask. The NO concentration was increased at 1 ppm/min (parts per million) until a maximum of 25 ppm and continued for 120 min and then weaned at 1 ppm/min. Dyspnoea was assessed with the Borg score, oxygenation by pulse oximetry, and haemodynamic status by shock index (HR/SBP).
  
  
  RESULTS
  Eight patients were enrolled. All patients tolerated the entire protocol without adverse events, and all had decreased numerical Borg score by >50%. The changes from baseline to 155 min were as follows: Borg score 7.5±2.5 to 2.3±1.9 (p=0.06, Signed rank test), SaO2% 93±5 to 97±3 and shock index 1.0±0.11 to 0.86±0.09. No patient experienced worsening during weaning.
  
  
  CONCLUSIONS
  Inhaled NO reduced dyspnoea without adverse events in eight patients with severe submassive PE. This protocol can serve as the basis for a phase II trial or for a compassionate use protocol.
authors.affiliation: Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Kline
authors.affiliation: Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA.
authors.forename: Jackeline
authors.initials: J
authors.lastname: Hernandez
authors.affiliation: Department of Emergency Medicine, Baylor School of Medicine, Houston, Texas, USA.
authors.forename: John S
authors.initials: JS
authors.lastname: Garrett
authors.affiliation: Department of Emergency Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA.
authors.forename: Alan E
authors.initials: AE
authors.lastname: Jones
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D001993:Bronchodilator Agents / Q000008:administration & dosage*; D004417:Dyspnea / Q000188:drug therapy / Q000209:etiology; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000008:administration & dosage*; D010865:Pilot Projects; D011655:Pulmonary Embolism / Q000188:drug therapy*
chemical_list: D001993:Bronchodilator Agents; D009569:Nitric Oxide
keywords: pulmonary embolism