The order for an intravenous (IV) drip often renders healthcare professionals (HCPs) opting for normal saline pints for many patients – depending on their varied conditions. Regarded as one of the most important essentials of healthcare, the use of IV drips vary from preventing dehydration, maintaining blood pressure, or even for medicine administration.

Despite old evidence of potentially harming kidneys, normal saline has been the most widely used IV fluid in the US and other parts of the world. Countries like the UK and Australia, on the other hand, widely use IV solutions containing potassium and other electrolytes or elements. These fluids also include saline but are more like plasma.

However, latest studies raise questions regarding the type of dripschosen for all patients.

Specifically, two large sister studies have discovered that running a different IV fluid – instead of the usual saline – largely reduced the risk of death or kidney damage in the month after they were enrolled in the study. One of the studies focuses on patients in the intensive care unit (ICU) and the other report is on adults who were not critically ill. The research is recently presented at a critical care conference in San Antonio and published by the New England Journal of Medicine.

Two reports show significant results in the grand scheme of things

Study author, director of the medical ICU at Vanderbilt University Medical Centre and an associate professor of medicine in its Division of Allergy, Pulmonary, and Critical Care Medicine, Dr Todd Rice remarks: “Saline has been used in practice for over a century. We actually heard from a number of people that there couldn't have been much difference between these two (IV fluids), because we would have already known it if there was.”

Out of the roughly 16,000 critically ill patients, 10.3% of those who were administered balanced crystalloids and 11.1% of those given saline perished in the hospital within a month. Other data accumulated showed severe kidney events arose in 14.3% of the ’balanced‘ group and 15.4% in the saline cohort.

The other study on 13,000 patients who were not critically ill concluded that there was no difference in how soon surviving patients were discharged in the month after they came to the emergency room. Despite this, investigators noted the reduced incidence of severe kidney events in the “balanced group” (4.7%) as compared to saline group (5.6%).

Loosely translating these results, 111 patients that received saline would need to be treated with balanced crystalloids instead in order to avert one adverse renal event.

Recent studies show that other fluids that cost about the same would have been better for patients. Photo credit:
Recent studies show that other fluids that cost about the same would have been better for patients. Photo credit:

Study leader Dr Matthew Semler comments on the application of these findings for roughly 30 million of the general public hospitalized annually in the US. He says, “there are tens or hundreds of thousands of patients who would be spared death or severe kidney problems by using balanced fluids instead of saline.”

Numerically, US researchers estimate that the difference could equate 50,000 to 70,000 fewer deaths and 100,000 lesser cases of kidney failure each year in the country.

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Time to make the change in priority?

With these latest findings, doctors are hoping the results will convince more hospitals to switch. Dr John Kellum, critical care specialist at the University of Pittsburgh says, “we’ve been sounding the alarm for 20 years [about the possible harms from saline].” He places the hesitation to change purely down to inertia.

Dr Semler believes that even though both saline and crystalloid solutions with plasma-like electrolyte composition are frequently utilized in various hospitals, the reasons HCPs opt for them depends on how they were trained.

“Internal medicine physicians tend to use saline while anaesthesiologists and surgeons tend to use balanced fluids more,” he claims.

Leading by example, Vanderbilt themselves have made the switch to prioritize balanced fluids. Keen followers will not have a hard time making the transition as – for one – both fluids roughly cost the same which is about US$1 to US$2 per pint. Aside from that, both types of fluids are mass-produced by multiple suppliers.

Study bias cannot be ignored

Dr David Hager, associate director of the medical ICU at the Johns Hopkins Hospital believes other studies will spin off from these findings. He notes certain bias points such as the conduction of this study at a sole medical centre and the unblinded nature of it – doctors knowing that they were giving one fluid versus another could have subconsciously impacted their decisions.

Furthermore, researchers remark that patients who were not critically ill and received IV fluids in the emergency room did not always receive the same fluid type after admission. Dr Rice also adds that the results could be attributed to patients being more vulnerable in the early stages of a condition. MIMS

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