title: Can the normobaric oxygen paradox (NOP) increase reticulocyte count after traumatic hip surgery?
abstract: OBJECTIVE
  To determine if the normobaric oxygen paradox (NOP) was effective in increasing reticulocyte count and reducing postoperative requirements for allogeneic red blood cell transfusion after traumatic hip surgery.
  
  
  METHODS
  Prospective, randomized, double blinded, multi-center study.
  
  
  METHODS
  Surgical wards of two academic hospitals.
  
  
  METHODS
  85 ASA physical status 1 and 2 patients undergoing surgery for traumatic hip fracture.
  
  
  METHODS
  Patients were randomly assigned to receive 30 minutes of air [air group (control); n = 40] or 30 minutes of 100% oxygen (O2 group; n = 14) at 15 L/min every day from the first postoperative day (POD 1) until discharge.
  
  
  METHODS
  Venous blood samples were taken at admission and after surgery on POD 1, POD 3, and POD 7. Hemoglobin (Hb), hematocrit (Hct), reticulocytes, hemodynamic variables, and transfusion requirements were recorded, as were hospital length of stay (LOS) and mortality.
  
  
  RESULTS
  Full analysis was obtained for 80 patients. On hospital discharge, the mean increase in reticulocyte count was significantly higher in the O2 group than the air group. Percent variation also increased: 184.9% ± 41.4% vs 104.7% ± 32.6%, respectively; P < 0.001. No difference in Hb or Hct levels was noted at discharge. Allogeneic red blood cell transfusion was 7.5% in the O2 group versus 35% in the air group (P = 0.0052). Hospital LOS was significantly shorter in the O2 group than the air group (7.2 ± 0.7 days vs 7.8 ± 1.6 days, respectively; P < 0.05).
  
  
  CONCLUSIONS
  Transient O2 administration increases reticulocyte count after traumatic hip surgery. Hospital LOS also was shorter in the O2 group than the control group. Allogeneic red blood cell transfusion was reduced in the O2 group but it was not due to the NOP mechanism.
authors: Department of Anesthesiology, Centre Hospitalier Hornu-Frameries, 7301 Hornu, Belgium.
authors: Pierre
authors: P
authors: Lafère
authors: Thomas
authors: T
authors: Schubert
authors: David
authors: D
authors: De Bels
authors: Peter
authors: P
authors: Germonpré
authors: Costantino
authors: C
authors: Balestra
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000740:Anemia / Q000517:prevention & control; D004311:Double-Blind Method; D017707:Erythrocyte Transfusion; D005260:Female; D006400:Hematocrit; D006454:Hemoglobins / Q000378:metabolism; D006620:Hip Fractures / Q000097:blood / Q000601:surgery*; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D010102:Oxygen Inhalation Therapy / Q000379:methods*; D011182:Postoperative Care / Q000379:methods*; D011183:Postoperative Complications / Q000517:prevention & control; D011446:Prospective Studies; D017701:Reticulocyte Count
chemical_list: D006454:Hemoglobins