Intensive care units (ICUs) with the possibility to apply invasive ventilation are increasingly available in low– and middle–income countries (LMICs). The first part of this thesis focuses on epidemiology, practice of ventilation and outcome in patients receiving invasive ventilation in ICUs in LMICs. The second part of this thesis focuses on the diagnostic and prognostic properties of pulse oximetry and lung ultrasound (LUS) as alternatives to BGA and conventional radiological imaging in critically ill patients in ICUs in LMICs. The overarching hypotheses tested are: (1) epidemiology, practice of ventilation and outcome in invasively ventilated patients in LMICs differ from that in high income countries; and (2) pulse oximetry and LUS are usable surrogates for in monitoring of ventilated critically ill patients. The thesis reports on the results of one observational study of epidemiology, practice of ventilation and outcome in resource–limited ICUs in Asian LMICs, and a series investigations into the use of SpO2/FiO2 and LUS in critically ill patients, both in a resource–rich and one resource–limited setting
