Intravenous Fluid Therapy

Cholera and the first intravenous infusions

A biographical article on Thomas Latta says the 1832 cholera pandemic travelled across Europe with devastating mortality, that doctors had speculated about the benefits of intravenous therapy beforehand but none had tried it, and that Latta performed intravenous infusions in 1832. The same article says the treatment disappeared after his death in 1833, and attributes this mainly to general medical skepticism, a lack of biochemical and physiological knowledge, and poor patient selection. It adds that no later pandemic of comparable size supplied a catalyst for development in this field.

A review in Clinical Infectious Diseases describes three advances in fluid therapy that emerged only briefly during the 1832 outbreak in Britain: intravenous fluid therapy, oral salt and water treatment, and chemical analysis of body fluids. It credits William Stevens with uncontrolled evidence that fluids and salt could prevent death, William O'Shaughnessy with finding that water, salt and carbonate were lost in people with cholera, and Latta with introducing intravenous fluid therapy.

From early attempts to modern practice

The review by Daly and DuPont says early attempts to establish fluid therapy failed to become cornerstones of clinical medicine because of a lack of convincing science and because of personal animosities. It places the development of the modern era of rehydration for cholera and dehydrating diarrhea between the period just after World War II and the 1970s, and describes that process as an example of translational research that applied biochemical and physiological observations to the clinic.

The sources reviewed for this page do not document the development of individual solutions such as Hartmann's solution, and they do not trace twentieth-century changes in fluid practice in detail. A NICE table lists Hartmann's solution among isotonic crystalloids and names it alongside 0.9% sodium chloride, which shows it remains in current guidance but says nothing about its origin. A recent executive summary from the International Fluid Academy presents the contemporary view that intravenous fluid should be treated like any other pharmacological prescription, with attention to harms as well as benefits.

Crystalloids and colloids

The Cochrane review of colloids versus crystalloids describes crystalloids as solutions with small molecules that are cheap, easy to use and provide immediate fluid resuscitation, though they may increase edema. It describes colloids as solutions with larger molecules that cost more and may expand the volume inside blood vessels more quickly, but that may induce allergic reactions, blood clotting disorders and kidney failure. The review groups colloids into starches, dextrans, gelatins, and albumin or fresh frozen plasma.

NICE lists 0.9% sodium chloride and Hartmann's solution as isotonic crystalloids, together with 0.9% sodium chloride containing 5% glucose. Balanced solutions, also called balanced crystalloids or balanced multielectrolyte solutions, are the term used in the trials discussed below for fluids such as lactated Ringer's solution and Plasma-Lyte, compared against saline, meaning 0.9% sodium chloride.

Resuscitation, replacement and maintenance

The International Fluid Academy summary names three main indications for intravenous fluid: resuscitation, replacement and maintenance. It also points to fluid given as a drug diluent or to keep a catheter open, which it calls fluid creep. NICE guidance for adults frames assessment around five Rs: resuscitation, routine maintenance, replacement, redistribution and reassessment.

In this page the phrase intravenous fluid therapy means these hospital uses. It does not mean the elective vitamin, mineral and hydration infusions sold by drip bars and wellness clinics, which a survey of health professionals refers to as commercially available intravenous nutrient therapies. Those are covered on the pages IV Therapy and IV Hydration Therapy.

What guidelines say the treatment is for

NICE guideline CG174, published in December 2013 and last updated in May 2017, covers the general principles of intravenous fluid therapy in hospital inpatients aged 16 and over. It says the aim is to help prescribers understand the optimal amount and composition of fluids and the best rate for giving them. The guideline does not cover pregnant women or people with severe liver or renal disease, diabetes or burns. NICE reported in June 2020 that it had found no new evidence affecting the recommendations.

NICE guideline NG29, published in December 2015 and updated in June 2020, covers intravenous fluid therapy for children and young people under 16 in hospital. The 2020 update amended a recommendation to clarify the use of isotonic crystalloids for routine maintenance in term neonates. The guideline's training section refers readers to the adult guideline.

A prescribed, monitored treatment

Both NICE guidelines treat intravenous fluid as something assessed and monitored for each patient. The adult guideline includes advice on monitoring and says that if a patient receiving fluids with a high chloride content develops hyperchloremia or acidemia, the fluid prescription should be reassessed. It also notes that the fluid quantities it describes for maintenance do not meet a person's nutritional needs, and it points to separate NICE nutrition support guidance. Nutritional care is covered on the pages Dietetics and Nutritional Therapy.

This page gives no volumes, rates or regimens. Those details depend on the individual patient and are set by the clinical team using the guidelines cited here, and they are outside the scope of an encyclopedia entry.

Established clinical uses

The International Fluid Academy summary says there are three main indications for intravenous fluid in the perioperative and critical care setting: resuscitation, replacement and maintenance. The Cochrane review describes fluid resuscitation for critically ill people who lose fluid through conditions such as sepsis, trauma or burns and who need additional fluid urgently to prevent dehydration or kidney failure. NICE describes the purpose of its adult guideline as improving fluid prescribing and outcomes among people in hospital.

How this differs from elective drips

A survey of 188 health professionals in Poland, conducted between April 2019 and March 2020, asked about commercially available intravenous nutrient therapies. The authors describe these as procedures that allegedly offer numerous benefits and quick results and that are widely advertised on the websites of drip bars and health clinics. The most commonly named justification among respondents was a diagnosed nutrient deficiency, at 37.8 percent, and 25.5 percent said there was no good rationale for using them. This is a preliminary survey of opinion, drawn mainly from postgraduate public health course attendees, and it is not a measure of effectiveness.

The evidence and guidance cited in this page concern fluids given to hospital patients with a clinical need. None of it should be carried over to elective vitamin or hydration drips, which are discussed on the pages IV Therapy, IV Hydration Therapy and Intravenous Iron Infusion.

Balanced solutions versus saline in adults

In SMART, a cluster-randomized crossover trial in five intensive care units at one academic center, 15,802 critically ill adults received saline or balanced crystalloids according to their unit. The primary outcome, a composite of death, new renal replacement therapy or persistent renal dysfunction within 30 days, occurred in 14.3 percent of the balanced group and 15.4 percent of the saline group (marginal odds ratio 0.91, 95% confidence interval 0.84 to 0.99). In-hospital mortality at 30 days was 10.3 and 11.1 percent (P=0.06). SALT-ED, a single-center trial in 13,347 adults treated in an emergency department and then admitted outside intensive care, found no difference in hospital-free days, and reported fewer major adverse kidney events with balanced crystalloids (4.7 versus 5.6 percent).

Later balanced-solution trials and consensus

The SPLIT trial, a double-blind cluster trial in four New Zealand intensive care units that enrolled 2278 patients, found no reduction in acute kidney injury with a buffered crystalloid compared with saline (9.6 versus 9.2 percent, relative risk 1.04). The larger PLUS trial randomized 5037 critically ill patients in 53 intensive care units in Australia and New Zealand to Plasma-Lyte 148 or saline. Death within 90 days occurred in 21.8 percent of the balanced group and 22.0 percent of the saline group, and the authors reported no evidence that death or acute kidney injury was lower with the balanced solution. The International Fluid Academy summary, which predates PLUS, states that balanced solutions should be preferred among crystalloids because they limit acid-base alterations and chloride load.

Colloids versus crystalloids

The 2018 Cochrane review searched to February 2018 and included 69 studies, 65 randomized and four quasi-randomized, with 30,020 critically ill participants. It found moderate-certainty evidence that starches, dextrans, and albumin or fresh frozen plasma probably make little or no difference to mortality compared with crystalloids, and low-certainty evidence for gelatins. Starches probably slightly increased the need for blood transfusion and for renal replacement therapy. Evidence on adverse events such as allergic reactions was very low certainty.

Children and maintenance fluids

A 2015 systematic review of 11 randomized trials of maintenance fluid in hospitalized children found that isotonic solutions reduced the risk of hyponatremia compared with hypotonic solutions (relative risk 0.50) without a significant increase in hypernatremia. An updated 2023 meta-analysis of 33 trials with 5049 children found isotonic fluid reduced mild hyponatremia (relative risk 0.38 at 24 hours or less and 0.47 beyond 24 hours, high-quality evidence), but increased hypernatremia in neonates, raised serum creatinine at 24 hours or less and lowered blood pH. The authors noted heterogeneity among the trials. NICE guideline NG29 recommends initially using isotonic crystalloids for routine maintenance in children and young people.

Limits of the evidence

The trials above were conducted in specific hospital populations, and several were single-center or cluster designs with fluids assigned by unit or time period. They do not address elective drips given to healthy people, and they do not show that any one fluid is preferable for every patient. The searches run for this page covered NICE guidance, trials and reviews of balanced versus saline fluids, Cochrane reviews of colloids, and reviews of pediatric maintenance fluid. Consensus statements beyond the International Fluid Academy summary were not reviewed.

Comparators and generalizability

The Cochrane review notes that fourteen included studies had crystalloid groups that received or may have received colloids, which might have influenced results, and that some studies carried risk of selection bias and selective outcome reporting. Differences between adults and children, between intensive care and emergency department settings, and between the fluids tested mean that findings for one fluid, population or setting should not be assumed to apply to another.

Fluid and electrolyte harms

NICE's adult guideline lists consequences of fluid mismanagement that hospitals should report as critical incidents: hypovolemia, pulmonary edema, hyponatremia, hypernatremia, peripheral edema and hyperkalemia. The International Fluid Academy summary notes that the last decade has seen growing interest in harms related to fluid overload and that appropriate perioperative management should maintain organ perfusion while limiting the amount of fluid given.

For children, NICE NG29 includes a section on managing hyponatremia that develops during intravenous fluid therapy. It advises changing a hypotonic fluid to an isotonic fluid if asymptomatic hyponatremia develops, and seeking immediate expert advice if acute symptomatic hyponatremia develops. The pediatric meta-analyses above describe iatrogenic hyponatremia as a complication linked to hypotonic maintenance fluid.

The International Fluid Academy summary and the Cochrane review also report fluid-specific concerns: chloride load and acid-base changes with saline, and, for colloids, kidney-related and blood-clotting concerns. The Cochrane review found that starches probably slightly increased renal replacement therapy and blood transfusion.

Catheter-related complications

A 2026 systematic review of dressing and securement methods for peripheral intravenous catheters, covering 15 randomized trials with 5542 participants, states that these catheters are widely used in hospitals and associated with high failure rates and patient safety risks. The outcomes it assessed included infiltration, extravasation, phlebitis and catheter-related bloodstream infection. The abstract reviewed does not give event rates for these complications, so no frequencies are reported here.

Training, oversight and care boundaries

NICE states that skilled and competent healthcare professionals should prescribe and administer intravenous fluids and assess and monitor patients receiving them. It recommends that hospitals establish systems so everyone involved is trained on the guideline principles and formally assessed and reassessed at regular intervals, and that each hospital have an IV fluids lead responsible for training, clinical governance, audit and review. These are guideline recommendations from a health technology body, not a registration scheme.

A health professional survey reported that 95.2 percent of respondents recognized health risks in commercial intravenous nutrient therapies, most often the lack of full information on a patient's health status and contraindications, the risk of overdose and interactions, and hypersensitivity reactions. Those concerns refer to elective infusions and are not findings about hospital fluid therapy. This page is information only and is not a substitute for assessment by a qualified clinician; no one should delay necessary care on the basis of it.