GENERAL DISREGARD Low-flow anesthesia is a beneficial but underused practice.

Low-flow anesthesia has been around for decades, but budget-conscious facilities are more interested than ever in the technique that limits waste of costly inhalational anesthetic agents while improving patient care and staff safety. Let's explore those benefits further.

1. Cost savings
Where is low-flow use most widespread? In third-world countries where the high cost of volatile agents desflurane and sevoflurane demand cost-savings measures wherever possible. The expense of volatile anesthetics directly affects your anesthesia budget — if your providers dropped flow rates from 2L per minute to 500cc per minute, for example, you'd realize several thousand dollars a year in savings per OR — so convince your providers to limit flows of the costliest agents. Isoflurane is inexpensive, so the potential cost savings of using it during low-flow anesthesia is nominal. If your providers use sevoflurane or desflurane, however, the cost savings can add up.

2. Less waste
The higher the flow of air and oxygen through your anesthesia machine, the more volatile agent the flow picks up and potentially releases into the atmosphere. The negative impact of waste anesthetic gases on the atmosphere is very small, but very real, and something you need to be conscious of limiting.

Perhaps a more immediate and tangible danger hits closer to home: Waste anesthesia gas also contaminates the OR and could harm your surgical team members, a potential danger regulated by OSHA. No worker should be exposed to a concentration of waste anesthetic gases >2 parts per million (ppm) of any halogenated anesthetic agent, according to OSHA recommendations. When such agents are used in combination with nitrous oxide, levels of 0.5 ppm are achievable. Nitrous oxide, when used as the sole anesthetic agent, should be controlled so that no worker is exposed at 8-hour time-weighted average concentrations of >25 ppm during anesthetic administration, advises OSHA.

3. Better patient care
Low-flow anesthesia helps limit the risks of hypothermia and surgical site infections by letting you better maintain a patient's core temperature and humidity level.

During the normal breathing process, the air that enters the 23 levels of division in the lungs is heated and humidified. The temperature and humidity of breathed-in air aren't neutralized until the air reaches the 4th level. Sending cold, dry volatile anesthetics into the lungs makes that neutralization more difficult, which lowers a patient's core temperature and humidity level.

When humidity levels drop, the normal functioning of the lungs' mucus membranes is reduced, which inhibits breathing and could lead to mucus plugs and ventilation difficulties.

Volatile anesthetics can exacerbate hypothermia issues for patients already lying in cold ORs, without clothes, with large body surfaces uncovered and with internal organs potentially exposed. They're being injected with fluids that in most cases aren't heated to body temperature and, because they're sedated, can't shiver to generate muscle heat. All these factors combine to drop core temperatures, which can cause clotting issues, treatment-resistant heart arrhythmia and increased surgical site infection risks.

Machine advances
Newer anesthesia machines are designed to facilitate the delivery of low-flow anesthesia. When shopping for a new machine, its capacity for low gas flow is an important feature to consider. Some machines have default low-flow settings, so be sure the machines' capabilities match the goals of your providers. Machines that can deliver low-flow rates typically have advanced breathing circuits and absorbers, and more accurate electronic flowmeters that let providers deliver lower flows of anesthetic gases much more accurately than they could with mechanical components found on older models.