title: Changes in arterial blood gases after use of high-flow nasal cannula therapy in the ED.
abstract: BACKGROUND
  A high-flow nasal cannula (HFNC) has been used to treat patients with dyspnea. We identified changes in arterial blood gas (ABG) of patients visiting the emergency department (ED) with hypercapnic and nonhypercapnic respiratory failure after use of an HFNC.
  
  
  METHODS
  This study was a retrospective chart review of patients with respiratory failure who visited the hospital and used an HFNC in the ED. The study period was July 1, 2011, to December 31, 2013. Patients with Paco2 greater than 45 mm Hg before the HFNC ABG analyses were included in the hypercapnia group; others comprised the nonhypercapnia group. Primary outcomes were the changes in ABG before and after use of an HFNC in the hypercapnia and nonhypercapnia groups. Progression to noninvasive or invasive ventilation and mortality rates were also assessed.
  
  
  RESULTS
  A total of 173 patients were included after exclusion of 92 according to exclusion criteria. Eighty-one patients (hypercapnia group, 46, and nonhypercapnia group, 35) were included. Paco2 significantly decreased among all patients after use of HFNC (from 54.7±26.4 mm Hg to 51.3±25.8 mm Hg; P=.02), but the reduction was significant only in the hypercapnia group (from 73.2±20.0 to 67.2±23.4; P=.02). Progression to noninvasive or invasive ventilation and mortality rates were similar between the groups.
  
  
  CONCLUSIONS
  Use of an HFNC in patients with hypercapnia could show a significant trend of decrease in Paco2. Progression to noninvasive or invasive ventilation and mortality rates were similar in patients with and without hypercapnia.
authors: Department of Emergency Medicine, Gyeongsang National University School of Medicine, Jinju-si, Gyeongsangnam-do, Republic of Korea.
authors: Jin Hee
authors: JH
authors: Jeong
authors: Department of Emergency Medicine, Gyeongsang National University School of Medicine, Jinju-si, Gyeongsangnam-do, Republic of Korea. Electronic address: kloud14@hanmail.net.
authors: Dong Hoon
authors: DH
authors: Kim
authors: Department of Emergency Medicine, Gyeongsang National University School of Medicine, Jinju-si, Gyeongsangnam-do, Republic of Korea.
authors: Seong Chun
authors: SC
authors: Kim
authors: Department of Emergency Medicine, Gyeongsang National University School of Medicine, Jinju-si, Gyeongsangnam-do, Republic of Korea.
authors: Changwoo
authors: C
authors: Kang
authors: Department of Emergency Medicine, Gyeongsang National University School of Medicine, Jinju-si, Gyeongsangnam-do, Republic of Korea.
authors: Soo Hoon
authors: SH
authors: Lee
authors: Department of Emergency Medicine, Gyeongsang National University School of Medicine, Jinju-si, Gyeongsangnam-do, Republic of Korea.
authors: Tae-Sin
authors: TS
authors: Kang
authors: Department of Emergency Medicine, Gyeongsang National University School of Medicine, Jinju-si, Gyeongsangnam-do, Republic of Korea.
authors: Sang Bong
authors: SB
authors: Lee
authors: Department of Emergency Medicine, Gyeongsang National University School of Medicine, Jinju-si, Gyeongsangnam-do, Republic of Korea.
authors: Sang Min
authors: SM
authors: Jung
authors: Department of Emergency Medicine, Gyeongsang National University School of Medicine, Jinju-si, Gyeongsangnam-do, Republic of Korea.
authors: Dong Seob
authors: DS
authors: Kim
mesh_terms: D000368:Aged; D001784:Blood Gas Analysis / Q000295:instrumentation / Q000379:methods; D057785:Catheters / Q000009:adverse effects / Q000706:statistics & numerical data; D015897:Comorbidity; D018450:Disease Progression; D057286:Electronic Health Records; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D017052:Hospital Mortality; D006801:Humans; D006935:Hypercapnia / Q000175:diagnosis / Q000209:etiology / Q000628:therapy*; D008171:Lung Diseases / Q000150:complications*; D008297:Male; D010092:Oximetry; D010102:Oxygen Inhalation Therapy / Q000295:instrumentation / Q000379:methods*; D012121:Respiration, Artificial / Q000379:methods / Q000401:mortality; D012131:Respiratory Insufficiency / Q000209:etiology / Q000401:mortality / Q000628:therapy*; D012189:Retrospective Studies