Publication Type : Journal Article
Thematic Areas : Medical Sciences
Publisher : Pediatr Cardiol
Source : Pediatr Cardiol, Volume 38, Issue 5, p.959-964 (2017)
Url : https://www.ncbi.nlm.nih.gov/pubmed/28315943
Keywords : adolescent, blood gas analysis, Cardiac Catheterization, Cardiac Output, child, Child, Preschool, female, Humans, Hyperoxia, Hypertension, Pulmonary, infant, male, Oxygen consumption, Oxygen Inhalation Therapy, Retrospective Studies, Thermodilution
Campus : Kochi
School : School of Medicine
Department : Paediatric Cardiology
Year : 2017
Abstract : High inspired oxygen concentration (FiO 0.85) is administered to test pulmonary vascular reactivity in children with pulmonary hypertension (PH). It is difficult to measure oxygen consumption (VO) if the subject is breathing a hyperoxic gas mixture so the assumption is made that baseline VO does not change. We hypothesized that hyperoxia changes VO. We sought to compare the VO measured by a thermodilution catheter in room air and hyperoxia. A retrospective review of the hemodynamic data obtained in children with PH who underwent cardiac catheterization was conducted between 2009 and 2014. Cardiac index (CI) was measured by a thermodilution catheter in room air and hyperoxia. VO was calculated using the equation CI = VO/arterial-venous oxygen content difference. Data were available in 24 subjects (males = 10), with median age 8.3 years (0.8-17.6 years), weight 23.3 kg (7.5-95 kg), and body surface area 0.9 m (0.4-2.0 m). In hyperoxia compared with room air, we measured decreased VO (154 ± 38 to 136 ± 34 ml/min/m, p = 0.007), heart rate (91 [Formula: see text] 20 to 83 [Formula: see text] 21 beats/minute, p=0.005), mean pulmonary artery pressure (41 [Formula: see text] 16 to 35 [Formula: see text] 14 mmHg, p=0.024), CI (3.6 [Formula: see text] 0.8 to 3.3 [Formula: see text] 0.9 L/min/m, p = 0.03), pulmonary vascular resistance (9 [Formula: see text] 6 to 7 [Formula: see text] 3 WU m, p = 0.029), increased mean aortic (61 [Formula: see text] 11 to 67 [Formula: see text] 11 mmHg, p = 0.005), pulmonary artery wedge pressures (11 [Formula: see text] 8 to 13 [Formula: see text] 9 mmHg, p = 0.006), and systemic vascular resistance (12 [Formula: see text] 6 to 20 [Formula: see text] 7 WU m, p=0.001). Hyperoxia decreased VO and CI and caused pulmonary vasodilation and systemic vasoconstriction in children with PH. The assumption that VO remains unchanged in hyperoxia may be incorrect and, if the Fick equation is used, may lead to an overestimation of pulmonary blood flow and underestimation of PVRI.
Cite this Research Publication : L. Guo, Bobhate, P., Kumar, S., Vadlamudi, K., Kaddoura, T., Elgendi, M., Holinski, P., Coe, J. Y., Rutledge, J., and Adatia, I., “Hyperoxia Reduces Oxygen Consumption in Children with Pulmonary Hypertension.”, Pediatr Cardiol, vol. 38, no. 5, pp. 959-964, 2017.