Related Experiment Video
Updated: Aug 12, 2026

Magnetic Resonance Imaging Quantification of Pulmonary Perfusion using Calibrated Arterial Spin Labeling
Published on: May 30, 2011
A graphic approach for prediction of arterial oxygen tension at different concentrations of inspired oxygen
Abstract:
A rapid, simple method for predicting the arterial oxygen tension (PaO2) at any fractional concentration of inspired oxygen (FIO2) is presented. The method is based on a nomogram interrelating PaO2, arterial carbon dioxide tension (PaCO2) and FIO2, allowing rapid determination of the arterial to alveolar oxygen tension ratio a/A PO2. The applicability of the nomogram and its reliability for predicting the PaO2 at any FIO2 were studied prospectively in nine consecutive patients requiring mechanical ventilation (16 trials). On each occasion, a desired PaO2 was chosen and from the nomogram an FIO2 expected to yield this PaO2 was administered. The PaO2 was then measured. Actual PaO2 differed from desired PaO2 by a mean of 2.6 mm Hg (range 0 to 10 mm Hg, standard deviation (SD) 4.8). Retrospectively, we analyzed the nomogram's ability to predict the PaO2 +/- 9.6 mm Hg (2 SD) at varying FIO2. The overall sensitivity of this method was 85 percent (126 predictions out of 149 trials). We conclude that appropriate levels of supplemental oxygen can be rapidly and reliably chosen using the nomogram in selected patients.
Related Concept Videos
Guidelines For Measuring Vital Signs
Before taking a patient's vital signs, a nurse would consider and assess the patient's comfort level and ensure appropriate equipment is available.
Assessment of Diffusion and Perfusion
The Role of Diffusion in Respiration
Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration. In the respiratory system, this principle...
Special considerations while measuring oxygen saturation
Ensuring accuracy in vital sign recordings while prioritizing patient comfort and minimizing anxiety is important.
Treatment for Pulmonary Arterial Hypertension: Oxygen Therapy for Respiratory Failure
Oxygen therapy is vital in increasing and maintaining blood oxygen levels in PAH patients. As a result, it aids in reducing fatigue, improving...
Oxygen Transport in the Blood
Pulse Oximetry
Purpose
Average SpO2 values are greater than 95%. If the readings fall below 90%, it indicates that...

