These patients are on maximum settings of 60 liters per minute (LPM) at fraction of inspired oxygen (FiO2) 100%. During this time period, the number of patient ventilators in use, as well as low and high flow oxygen therapy for patients suffering primarily from COVID disease, had increased.Īccording to the hospital's Respiratory Therapist Manager Alicia Logan, “We seem to have approximately five patients each day using high-flow nasal cannula oxygen (HFNC). However, between April 8 to April 15, the hospital used 22 inches of liquid daily due to an increase in oxygen demand. To understand this further, facilities professionals should consult the “ Additional Ventilators May Pose a Risk to Hospital Gas Systems” guidance document published by the American Association for Respiratory Care.Īt Beverly Hospital, a typical day’s usage is 12 inches of liquid. There is a critical point in which safe operation of the system will reach its ultimate limit and could cause a shutdown of the entire bulk medical oxygen system. This will drop the actual pressure in the hospital network possibly setting off alarms and potentially disrupting the operation at the patient use points. These regulators have a fixed-flow capacity, and when it is exceeded, they are not able to maintain the desired pressure.
This drives the delivered oxygen temperatures lower to the point where frost and condensation form on the hospital line, posing risks to the safe operation of the hospital oxygen equipment.Īnother limiting factor for the supply system is the capacity of the pressure regulators that deliver the constant pressure during normal operation. However, when flows significantly exceed design rates, the ice further accumulates on the vaporizer fins, resulting in less surface area for heat exchange. Once the liquid oxygen is converted to oxygen gas, the pressure of the gas is pushed throughout the hospital into lines feeding medical oxygen connection ports in patient unit head walls.īy design, the ambient vaporizers will accumulate a small amount of ice at the inlet, while delivering gas near ambient temperatures on the outlet. This process occurs in the aluminum coils known as the ambient air vaporizers. Related to a potential accumulation of ice, systems constructed to the National Fire Protection Association's NFPA 99, Health Care Facilities Code, are designed to vaporize cryogenic (super-cooled) liquid oxygen from the storage vessel(s) using finned aluminum exchangers called ambient vaporizers. An unprecedented increase in medical oxygen demand (the number of patients needing oxygen above normal conditions) under certain circumstances can lead to shutdown of the hospital’s oxygen delivery system as a whole due to an inability for the hospital’s system to process the required oxygen. On April 17, 2020, Beverly Hospital received a letter from their medical oxygen supplier, Airgas, which reminded the hospital that the bulk medical oxygen supply system installed at their facility has limitations on the amount of vaporized medical oxygen that it can deliver to patients due to the capacity of the customer’s oxygen delivery system.ĬGA also encouraged gas customers to understand the facility’s oxygen supply system maximum operating capacity, considering tank volume, vaporizer capacity and in-house piping flow limits. The concern is hospital bulk medical oxygen systems may not be sized for the COVID 19 pandemic demand. Rich Gottwald, the president and CEO of the Compressed Gas Association (CGA), says, “There is no shortage of medical oxygen, nor do we anticipate any shortage.” That is partly because companies such as Airgas USA LLC, Linde plc and Air Products have ramped up production and shifted capacity to serve the most hard-hit areas of the country, he says. “The novel coronavirus attacks the lungs of infected patients, resulting in extraordinary usage of oxygen within the hospital,” she says.įortunately, the supply of medical oxygen to hospitals is not currently a concern. According to Patricia Covelle, associate chief nursing officer at Beverly Hospital, an urban facility and a member of Beth Israel Lahey Health System, just outside Boston. Extraordinary usageĮxtreme pressure has been put on the system due to the patient treatment efforts of COVID-19. To assist in determining the demand, Medical Air and Oxygen Capacity Tools have been posted to the ASHE COVID-19 Resources webpage. If the hospital system does not have the capacity to handle a surge of oxygen demand, the hospital can experience a reduction in oxygen pressure or a shutdown of their entire oxygen delivery system.
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