title: Use of an impedance threshold device to treat severe hypotension in a pregnant woman: case report and review of the literature.
abstract: BACKGROUND
  Impedance threshold device technology harnesses the patient's normal physiological mechanisms to increase circulation during hypotensive crises. We report the first clinical use of one version of this device on a spontaneously breathing hypotensive pregnant woman.
  
  
  OBJECTIVE
  The objective of our study was to report this case to help Emergency Medical Service rescue personnel to noninvasively treat hypotensive but conscious spontaneously breathing patients.
  
  
  METHODS
  A 28-year-old woman who was 21 weeks pregnant developed frank syncope at home but recovered spontaneously. When Emergency Medical Service paramedics arrived, her initial blood pressure and heart rate were 115/80 mm Hg and 125 beats/min, respectively. She suddenly complained of feeling anxious and developed profound bradycardia and hypotension, followed by 20 s of asystole. An impedance threshold device (ResQGARD™) with -7 cmH2O resistance to inspiration was rapidly applied using a facemask. After four spontaneous breaths, blood pressure increased from 62/40 mm Hg to 106/66 mm Hg. She was hemodynamically stable thereafter.
  
  
  CONCLUSIONS
  In this case report, the multiple physiological effects of inspiration through -7 cmH2O resistance helped this pregnant hypotensive patient to rapidly and noninvasively restore adequate perfusion and reduced the duration of her hypotensive episode. To our knowledge, this is the first report of this technology in a pregnant hypotensive but spontaneously breathing patient.
authors.affiliation: Department of Emergency Medicine, University of Minnesota Medical Center, Minneapolis, Minnesota; Service des Urgences, Hôpital Lariboisière, Assistance Publique-Hôpitaux de Paris, Université Paris, Paris, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Segal
authors.forename: David I
authors.initials: DI
authors.lastname: Page
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Lick
authors.forename: Daryl D
authors.initials: DD
authors.lastname: Doering
authors.forename: Demetris
authors.initials: D
authors.lastname: Yannopoulos
mesh_terms: D000328:Adult; D001919:Bradycardia / Q000150:complications / Q000628:therapy*; D004632:Emergency Medical Services / Q000379:methods*; D005260:Female; D006801:Humans; D007022:Hypotension / Q000150:complications / Q000628:therapy*; D001239:Inhalation; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000628:therapy*; D012121:Respiration, Artificial / Q000379:methods*; D013575:Syncope / Q000209:etiology
keywords: cardiovascular collapse; hypotension; impedance threshold device; pregnancy