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HRF Overview

Defining hypoxic respiratory failure (HRF)

HRF is a relative deficiency of oxygen in arterial blood, often associated with insufficient ventilation.1 This deficiency can be reflected by progressive respiratory and metabolic acidosis and remains a persistent challenge in the management of some newborns.2,3

Common underlying diseases of HRF*

  • No underlying lung disease4
  • Acute lung injury
  • Surfactant deficiency or inactivation
  • Pulmonary edema, volume loss
  • Airway obstruction with gas trapping
  • Surfactant inactivation
  • Pneumonitis
  • Streaky lungs with fluid in the minor fissure
  • Mild hypoxemia
  • Occasionally profound and/or prolonged hypoxemia
  • Patchy infiltrates and/or ground glass appearance
  • Hypoxemia and systemic hypotension
  • Group B streptococcus or gram-negative organisms

Transient tachypnea was not one of the primary diagnoses of patients in the INOMAX pivotal trials.


*© Crown copyright [2000-2005] Aukland District Health Board.

Images courtesy of John P. Kinsella, MD, and Steven H. Abman, MD.

HRF in Neonates: Pathophysiology2

Pathophysiology of HRF in neonates2:

  • Intrapulmonary shunt: Pulmonary arterial blood reaches the pulmonary venous side without passing through ventilated areas of the lung
  • Extrapulmonary shunt (PPHN): Right-to-left shunting of blood bypasses the lung through fetal channels (patent ductus arteriosus and/or foramen ovale)
  • Ventilation/perfusion (V/Q) mismatch: Imbalance between ventilation and perfusion

Decreased V/Q

Normal V/Q