### Abstract

A Dl_{O2} estimate which accounts for the nonlinearity of the oxygen dissociation curve using the Kelman blood gas routines is presented here. The simultaneous differential equations that describe O_{2} and CO_{2} diffusion between alveolar gas and pulmonary capillary blood in lung compartments with different V̇a/Q̇ ratios were solved numerically with a Runge-Kutta algorithm. These integrated estimates were compared to Dl_{O2} estimates the assume the oxygen dissociation curve is linear. In 140 gas exchange data sets from 18 healthy male subjects previously collected at rest and during exercise it was found that Dl_{O2} estimates based on linear dissociation curves exceeded integrated Dl_{O2} estimates by 14, 31, and 55 percent when the Pi_{O2} was 80, 100, and 148 Torr, respectively. We conclude that the linear approximation is accurate when Pi_{O2} is less than 100 Torr but that comparisons of Dl_{O2} estimates at different levels of inspired oxygen must allow for the difference in curvature of the oxygen dissociation curve as a function of Pi_{O2}.

Original language | English (US) |
---|---|

Pages (from-to) | 279-288 |

Number of pages | 10 |

Journal | Respiration Physiology |

Volume | 73 |

Issue number | 3 |

DOIs | |

State | Published - 1988 |

Externally published | Yes |

### Fingerprint

### Keywords

- Bohr integration
- Hypoxia
- Inert gases
- Normoxia
- Oxygen diffusing capacity

### ASJC Scopus subject areas

- Physiology
- Pulmonary and Respiratory Medicine

### Cite this

_{O2}with nonlinear dissociation curves and Va/Q̇ inequality.

*Respiration Physiology*,

*73*(3), 279-288. https://doi.org/10.1016/0034-5687(88)90050-3

**Estimating steady-state Dl _{O2} with nonlinear dissociation curves and Va/Q̇ inequality.** / Hempleman, Steven C; Gray, Andrew T.

Research output: Contribution to journal › Article

_{O2}with nonlinear dissociation curves and Va/Q̇ inequality',

*Respiration Physiology*, vol. 73, no. 3, pp. 279-288. https://doi.org/10.1016/0034-5687(88)90050-3

}

TY - JOUR

T1 - Estimating steady-state DlO2 with nonlinear dissociation curves and Va/Q̇ inequality

AU - Hempleman, Steven C

AU - Gray, Andrew T.

PY - 1988

Y1 - 1988

N2 - A DlO2 estimate which accounts for the nonlinearity of the oxygen dissociation curve using the Kelman blood gas routines is presented here. The simultaneous differential equations that describe O2 and CO2 diffusion between alveolar gas and pulmonary capillary blood in lung compartments with different V̇a/Q̇ ratios were solved numerically with a Runge-Kutta algorithm. These integrated estimates were compared to DlO2 estimates the assume the oxygen dissociation curve is linear. In 140 gas exchange data sets from 18 healthy male subjects previously collected at rest and during exercise it was found that DlO2 estimates based on linear dissociation curves exceeded integrated DlO2 estimates by 14, 31, and 55 percent when the PiO2 was 80, 100, and 148 Torr, respectively. We conclude that the linear approximation is accurate when PiO2 is less than 100 Torr but that comparisons of DlO2 estimates at different levels of inspired oxygen must allow for the difference in curvature of the oxygen dissociation curve as a function of PiO2.

AB - A DlO2 estimate which accounts for the nonlinearity of the oxygen dissociation curve using the Kelman blood gas routines is presented here. The simultaneous differential equations that describe O2 and CO2 diffusion between alveolar gas and pulmonary capillary blood in lung compartments with different V̇a/Q̇ ratios were solved numerically with a Runge-Kutta algorithm. These integrated estimates were compared to DlO2 estimates the assume the oxygen dissociation curve is linear. In 140 gas exchange data sets from 18 healthy male subjects previously collected at rest and during exercise it was found that DlO2 estimates based on linear dissociation curves exceeded integrated DlO2 estimates by 14, 31, and 55 percent when the PiO2 was 80, 100, and 148 Torr, respectively. We conclude that the linear approximation is accurate when PiO2 is less than 100 Torr but that comparisons of DlO2 estimates at different levels of inspired oxygen must allow for the difference in curvature of the oxygen dissociation curve as a function of PiO2.

KW - Bohr integration

KW - Hypoxia

KW - Inert gases

KW - Normoxia

KW - Oxygen diffusing capacity

UR - http://www.scopus.com/inward/record.url?scp=0023708387&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0023708387&partnerID=8YFLogxK

U2 - 10.1016/0034-5687(88)90050-3

DO - 10.1016/0034-5687(88)90050-3

M3 - Article

VL - 73

SP - 279

EP - 288

JO - Respiratory Physiology and Neurobiology

JF - Respiratory Physiology and Neurobiology

SN - 1569-9048

IS - 3

ER -