Identifying critical DO2 with compensatory reserve during simulated hemorrhage in humans.
Transfusion
; 62 Suppl 1: S122-S129, 2022 08.
Article
em En
| MEDLINE
| ID: mdl-35733031
ABSTRACT
BACKGROUND:
Based on previous experiments in nonhuman primates, we hypothesized that DO2 crit in humans is 5-6 ml O2 ·kg-1 min-1 . STUDY DESIGN ANDMETHODS:
We measured the compensatory reserve (CRM) and calculated oxygen delivery (DO2 ) in 166 healthy, normotensive, nonsmoking subjects (97 males, 69 females) during progressive central hypovolemia induced by lower body negative pressure as a model of ongoing hemorrhage. Subjects were classified as having either high tolerance (HT; N = 111) or low tolerance (LT; N = 55) to central hypovolemia.RESULTS:
HT and LT groups were matched for age, weight, BMI, and vital signs, DO2 and CRM at baseline. The CRM-DO2 relationship was best fitted to a logarithmic model in HT subjects (amalgamated R2 = 0.971) and a second-order polynomial model in the LT group (amalgamated R2 = 0.991). Average DO2 crit for the entire subject cohort was estimated at 5.3 ml O2 ·kg-1 min-1 , but was ~14% lower in HT compared with LT subjects. The reduction in DO2 from 40% CRM to 20% CRM was 2-fold greater in the LT compared with the HT group.CONCLUSIONS:
Average DO2 crit in humans is 5.3 ml O2 ·kg-1 min-1 , but is ~14% lower in HT compared with LT subjects. The CRM-DO2 relationship is curvilinear in humans, and different when comparing HT and LT individuals. The threshold for an emergent monitoring signal should be recalibrated from 30% to 40% CRM given that the decline in DO2 from 40% CRM to 20% CRM for LT subjects is located on the steepest part of the CRM-DO2 relationship.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Hipovolemia
/
Pressão Negativa da Região Corporal Inferior
Limite:
Animals
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Female
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Humans
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Male
Idioma:
En
Revista:
Transfusion
Ano de publicação:
2022
Tipo de documento:
Article