Among the collateral damage of Hurricane Maria’s havoc on Puerto Rico is the shutdown of several factories that produce upward of 40 percent of the intravenous fluids that many Americans suffering from a wide spectrum of illness depend on daily. (Actually, the hurricane itself didn’t grind things to a halt so much as the ongoing power outage that continues to render large swaths of the island largely unlivable.) As a result, an already massive IV fluid shortage underway in the U.S. prior to the hurricane has become much worse.

This increasingly dire situation has forced many of us, even at some of most prestigious hospitals in the United States, to come up with alternative solutions for hydrating our patients. And this is where things have gotten interesting. Because as much as I want Puerto Rico to return to full operating capacity for a number of reasons, IV bag production among them, our months of being forced to do without have taught us valuable lessons about IV bag use, the practice of rehydration, and American health care more generally.

In medicine as it is practiced in the United States, when asked to choose between two equally effective strategies, doctors tend to choose the more expensive option. To combat this, there are national campaigns (apparently ineffective ones) designed to encourage physicians to “Choose Wisely” when considering what tests and treatments to order for their patients. But as my colleagues and I have manifestly demonstrated in our lackluster response to these efforts over the past several years, spending more money on something is kind of the American way, because spending more feels like doing more, measurable upside be damned.

Here’s where Hurricane Maria comes in: IV fluids are a perfect example of our tendency to spend more and subject patients to invasive approaches when less invasive measures would suffice. We’ve long known that in patients who can tolerate oral fluids (i.e. they aren’t vomiting or otherwise excreting more liquid than they consume), IV fluids offer no advantage in rehydrating patients with dehydration.

IV fluids are a perfect example of our tendency to spend more and subject patients to invasive approaches when less invasive measures would suffice.

In fact, in many cases, IV fluids are actually worse than oral fluids for treating dehydration, because so many medical providers unthinkingly order sodium chloride solutions (aka “normal saline”) that contain no glucose and, unlike our natural physiology, are highly acidic. And for rehydration, glucose is basically as important as sodium. The two compounds work together to pull water into shriveled cells that have been deprived of ample water. We’ve known this convenient nugget since the middle of the 20th century. In fact, the discovery of a sodium-glucose transporter tunnel reaching out from the surfaces of our cells’ membranes is perhaps the single most lifesaving breakthrough in the history of molecular biology. Not antibiotics. Not chemotherapy. Just a humble protein clinging to the pliable rims of our cells, creating a kind of molecular crawl space through which glucose and sodium can be shunted into impoverished cells, which in turn creates a biochemical enticement for water to follow along that it literally cannot resist. When sodium and glucose enter the interior of a cell, water will—actually, it must—enter a cell in accordance with the laws of biophysics and chemistry. This is the definition of osmosis. And yet, most IV fluid formulations do not contain the right balance of electrolytes to optimize cellular hydration.

Back in the 1960s, Richard Cash led research in what is now Bangladesh that demonstrated that you need not slake the thirst of dying cholera victims with a needle, small tube shoved into the arm, and bag of expensive-to-produce sterile fluids. Instead, “oral rehydration salts” engineered to create the optimal conditions for our friend the sodium-glucose linked transporter to coax water back into the cells worked just as well, and for far cheaper. If you could make Tang or Kool-Aid or Ovaltine, you could make ORS. The World Health Organization has delivered ORS to millions of people, and it estimates that 60 million lives have been saved as a result of this simple insight.

Better yet, we’ve learned since that you can still get most of the benefit without WHO-approved stockpiles of ORS. You can use a number of widely available commercial products that essentially replicate ORS, from sports drinks to Pedialyte. You can also make good oral rehydration solutions yourself at home for pennies: Just take 32 ounces of water and add 6 teaspoons of sugar and a half-teaspoon of salt. There are just two pitfalls to avoid, according to my colleague Regan Marsh, an emergency physician at Brigham and Women’s Hospital and a medical director for Partners in Health. First, fight the urge to sweeten it too much. “People want to make it more sugary because of the taste, but that proportion of salt and sugar is important.” Second, she says, is to resist the temptation to drink at a normal rate—let alone chugging the stuff. An ounce at a time every few minutes decreases the odds that the liquid will, um, return from whence it came.

For the first time in memory, my emergency department managed to decrease its use of IV fluids.

In the face of the IV fluid shortage here in the United States, my hospital and others like it have started to use these protocols. In fact, for the first time in memory, my emergency department managed to decrease its use of IV fluids. In September and October, over 200 1-liter bags were administered each week. By January, that number had dropped to below 100. “We should be doing this all the time,” one of my residents recently said to me, enthusiastically, after successfully treating a teenager with mild dehydration recovering from a viral stomach flu with oral hydration. Under normal circumstances, we probably would have placed an IV line, and given IV fluids, and felt mighty proud of ourselves. But now, we can rehydrate that same teen less expensively and save the IV fluids for the patients who really need them. While I wish it hadn’t taken a hurricane-aided shortage for us to modify our behavior, it’s actually reassuring to know that when we need to conserve resources, we can do so safely. If we could just do this in other areas of treatment before a crisis hit, then we’d truly be getting ahead.

Disclaimer: The opinions expressed in this article are solely those of the author and do not reflect the views and opinions of Brigham and Women’s Hospital.