How to calculate total demand of oxygen for a health care facility?

The first thing to do is to talk to clinicians in the hospitals and understand their common patient mix, burden of disease, and what they understand to be the demand for oxygen in their setting, whether it be a health clinic or hospital department. Consider this as well though: in some hospitals clinicians may not have had opportunity for adequate training in respiratory care, and after providing clinical training opportunities oxygen consumption may increase due to increased usage of pulse oximeters to diagnose and treat patients. Pulse oximetry also can help to prevent over-oxygenating a patient and conserve oxygen. Therefore, clinical training components are important.

We would also advocate looking at duplex systems – 2 smaller PSA systems than a large plant because compressors do not modulate, and electricity can be 70% the cost of 1 L of oxygen. Moreover, in some hospitals where we have converted from cylinders to piped oxygen, we have seen in some cases a 300% increase in use of oxygen. Note that the direct pipe system does not require a PSA plant at your hospital, it can be supplied by cylinders.

Not everyone is going to have plants at their hospital. Why? If someone has to go a pick up a cylinder- heavy, time consuming, difficult, might actually be neglected altogether. But when piped it is readily available at the patients’ bedside and you just have to hook up a nasal cannula or mask. This means patients are getting low flows of oxygen much earlier and higher flows when they need it. So, your oxygen consumption can often go up. Distribution system also depends on if you are piping filling cylinders, working hours, size, etc.

The tool that we use to calculate this is from the OGSI website, found at this link here: https://www.ogsi.com/product/hospital-systems/. You should check this against what your facility is doing in terms of treatment and clinical services, you may need to adjust accordingly. Here is the formula:

Hospital System Sizing Estimator:

[# of beds x 0.75 liters per minute (LPM)] + [# of other outlets (ICU, Operating Theatre, etc.) x 10 liters per minute (LPM)] = total liters per minute (LPM)

*Liters per minute (LPM) x 2.1 = Standard Cubic Feet per Hour (SCFH)

FAQ by Assist International

Oxygen consumption Calculation Tool by OCC