key: cord-0771996-0biqxwhi
authors: Arora, N.; Dennis, A.; Willson, J.; Norrie, J.; Tunstall, M.
title: Delivery of oxygen by standard oxygen flowmeters
date: 2021-07-26
journal: Anaesthesia
DOI: 10.1111/anae.15548
sha: 8d733e0f800ab22218b92a7516e4807cf59fd604
doc_id: 771996
cord_uid: 0biqxwhi

nan

The last year has seen hospitals worldwide face multiple challenges in the face of the COVID-19 pandemic. This has included oxygen shortages, both locally [1] and nationally [2] . Guidance was offered by the Medicines and Healthcare products Regulatory Agency to manage this high oxygen demand [3] . We tested several standard oxygen flowmeters connected to our hospital's 400 kPa pipeline oxygen supply at 5, 10 and 15 l.min -1 and maximum flow rate using an electronic flowmeter (Certifier FA Plus 4080, TSI Incorporated, MN, USA) using a 1 m length of standard green bubble oxygen tubing. We found that the tested flow was within 5% of the indicated value, which is within reasonable limits given the difficulty in perfectly aligning the float. When the flowmeters were fully opened, however, and the float moved beyond the calibrated markers, the maximum flow rates measured were between 65 and 75 l.min -1 (Table 1 ). It has been previously reported that standard oxygen flowmeters can deliver up to 40 l.min -1 [4] , but our measurements suggest this could be a large underestimate. There needs to be awareness among healthcare workers that it is important to administer oxygen as prescribed, and that if higher flows of oxygen are used intentionally, a highflow rotameter should be used in order that oxygen use can be measured accurately, rather than simply turning a standard flowmeter up beyond the calibrated graduations.

N. Arora

Coronavirus: London hospital almost runs out of oxygen for Covid-19 patients. The Guardian

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Converting gasdriven ventilators from oxygen to air: environmental implications

No competing interests declared.