title: Oxygen saturation index and severity of hypoxic respiratory failure.
abstract: BACKGROUND
  The oxygenation index (OI = mean airway pressure, MAP × FiO2 × 100 : PaO2) is used to assess the severity of hypoxic respiratory failure (HRF) and persistent pulmonary hypertension of the newborn (PPHN). An indwelling arterial line or arterial punctures are necessary to obtain PaO2 for the calculation of OI. Oxygenation can be continuously and noninvasively assessed using pulse oximetry. The use of the oxygen saturation index (OSI = MAP × FiO2 × 100 : SpO2) can be an alternate method of assessing the severity of HRF.
  
  
  OBJECTIVE
  To evaluate the correlation between OSI and OI in the following: (1) neonates with HRF and (2) a lamb model of meconium aspiration syndrome.
  
  
  METHODS
  Human neonates: a retrospective chart review of 74 ventilated late preterm/term neonates with indwelling arterial access and SpO2 values in the first 24 h of life was conducted. OSI and OI were calculated and correlated. Lamb model: arterial blood gases were drawn and preductal SpO2 was documented in 40 term newborn lambs with asphyxia and meconium aspiration. OI and OSI were calculated and correlated with pulmonary vascular resistance (PVR).
  
  
  RESULTS
  Mean values of OSI and OI showed a correlation coefficient of 0.952 in neonates (mean value of 308 observations in 74 neonates) and 0.948 in lambs (mean value of 743 observations in 40 lambs). In lambs, with increasing PVR, there was a decrease in OI and OSI.
  
  
  CONCLUSIONS
  OSI correlates significantly with OI in infants with HRF. This noninvasive measure may be used to assess the severity of HRF and PPHN in neonates without arterial access.
authors.forename: Munmun
authors.initials: M
authors.lastname: Rawat
authors.forename: Praveen K
authors.initials: PK
authors.lastname: Chandrasekharan
authors.forename: Ashley
authors.initials: A
authors.lastname: Williams
authors.forename: Sylvia
authors.initials: S
authors.lastname: Gugino
authors.forename: Carmon
authors.initials: C
authors.lastname: Koenigsknecht
authors.forename: Daniel
authors.initials: D
authors.lastname: Swartz
authors.forename: Chang Xing
authors.initials: CX
authors.lastname: Ma
authors.forename: Bobby
authors.initials: B
authors.lastname: Mathew
authors.forename: Jayasree
authors.initials: J
authors.lastname: Nair
authors.forename: Satyan
authors.initials: S
authors.lastname: Lakshminrusimha
mesh_terms: D000818:Animals; D001784:Blood Gas Analysis; D004195:Disease Models, Animal; D006801:Humans; D000860:Hypoxia / Q000097:blood*; D007231:Infant, Newborn; D016014:Linear Models; D008471:Meconium Aspiration Syndrome / Q000097:blood*; D010092:Oximetry; D010100:Oxygen / Q000097:blood*; D010547:Persistent Fetal Circulation Syndrome / Q000097:blood*; D012131:Respiratory Insufficiency / Q000097:blood*; D012189:Retrospective Studies; D012756:Sheep; D014655:Vascular Resistance
chemical_list: D010100:Oxygen