Choosing Between Colloids and Crystalloids for IV Infusion

Nursing Practice Keywords Fluid resuscitation/‘5Rs’/ Crystalloids/Colloids Review This article has been Intravenous therapy double-blind peer reviewed In this article... ● Guidance on intravenous fluid therapy ● Parameters that may indicate the need for fluid resuscitation ● Compared risks and benefits of colloids and crystalloids

Choosing between colloids and crystalloids for IV infusion

Key points Author Lisa Smith is senior lecturer in emergency and urgent care at the University The loss of of Cumbria. circulating fluid volume can lead to Abstract Hypovolaemia resulting from illness or trauma can precipitate imbalances imbalances in in homoeostasis due to the loss of circulating fluid volume. By addressing homoeostasis hypovolaemia, homoeostasis can be restored, preventing hypoperfusion and subsequent organ dysfunction. Administering intravenous fluids can replace any lost Recognising, circulating volume. The National Institute for Health and Care Excellence outlines five assessing and ‘Rs’ of fluid therapy: resuscitation, routine maintenance, replacement, redistribution monitoring patients’ and reassessment. This article provides an overview of fluid therapy, covering the need for fluid NICE guidance and clarifying the differences between crystalloids and colloids, and therapy is crucial when to use them.

The ‘5Rs’ of Citation Smith L (2017) Choosing between colloids and crystalloids for IV infusion. intravenous fluid Nursing Times [online]; 113: 12, 20-23. administration are: resuscitation, routine o maintain its finely tuned essential. The National Institute for Health maintenance, homoeostasis, the human adult and Care Excellence’s (2017) guidance on IV replacement, body needs an average daily fluid fluid therapy in adults in hospital stresses redistribution and Tintake of 2.5-3 litres (Moore and the need for health professionals to under- reassessment Cunningham, 2017). It also requires a con- stand the physiology of fluid and electro- stant balance in the levels of nutrients, lyte balance. It also outlines five ‘Rs’ of Crystalloids and oxygen and water to preserve a stable fluid administration (Box 1). However, colloids, both internal environment (Moini, 2016). This there are many fluid replacement products plasma volume balance can be easily altered by illness or available and it is not always clear which expanders, are used injury, resulting in a loss of one or all of one should be used. to increase depleted these elements. This can lead to dehydra- This article provides an overview of the circulating volumes tion, hypoperfusion leading to reduced NICE guidance, highlighting what it oxygen uptake, and organ dysfunction, so means for health professionals adminis- To administer redressing the imbalance is essential. tering IV fluids. It also sheds light on the intravenous fluids, A reduction in oral fluid intake, the differences between crystalloid and colloid health professionals redistribution of fluid in the vascular solutions, and gives practical guidance on must understand spaces and a decreased circulating volume when each one should be used. what crystalloids need to be managed. Intravenous fluid and colloids do and therapy is one way of managing reduced Physiology when to use them fluid intake by reducing its effects and For effective tissue and organ perfusion, replacing lost fluids. maintenance of finely balanced levels of Recognising the signs and symptoms of oxygen, fluid and electrolytes (homoeo- fluid loss is necessary to identify the need stasis) is essential. Fluid volumes need to for fluid administration. Knowledge of be distributed into the intracellular and when to administer IV fluids, what type of extracellular spaces (the latter being fur- fluid to administer, and why they are all ther divided into the interstitial and

Nursing Times [online] December 2017 / Vol 113 Issue 12 20 www.nursingtimes.net Copyright EMAP Publishing 2017 This article is not for distribution Nursing Practice Review intravascular compartments). The move- Box 1. Five ‘Rs’ of intravenous affect patients’ cardiac performance ment of fluid between these spaces is con- fluid administration causing arrhythmias, heart failure and/or tinual. This enables cells to receive their cardiac arrest. If continued fluid loss is necessary supply of electrolytes such as l Resuscitation suspected, this should be checked and sodium, potassium and carbon. Along l Routine maintenance losses monitored. with oxygen, these are fundamental for l Replacement cell performance (Peate and Nair, 2016). l Redistribution Redistribution Homoeostasis is easily affected by any l Reassessment Redistribution of fluid can occur in critical insult to the body, be it from illness, injury, Source: National Institute for Health and Care illness. Fluid is lost from the circulatory trauma or medication. This imbalance can Excellence (2017) volume and moves into the tissues; this is quickly lead to worsening illness and/or called ‘third space loss’ (Frost, 2015). This impede recovery. Hypovolaemia will may be seen in patients with cardiac reduce the circulating fluid volumes, cause of any potential fluid loss. Finding failure, renal failure or sepsis, and oedema resulting in reduced electrolyte and and treating that cause, along with the may be present. To manage these patients oxygen supply to the cells. A large reduc- administration of fluid therapy, is essential effectively, increased monitoring, further tion in fluid volume can result in hypovol- to rule out refractory fluid loss. If not assessment and investigations are needed. aemic shock. Patients who go into hypo- addressed, this persistent loss of circulating In some cases, specialist intervention, volaemic shock need fluid resuscitation to volume could lead to: such as the monitoring of central venous maintain their cardiac output and organ l The need for further fluid resuscitation; pressure, kidney function tests or high perfusion. l Increased volumes of fluid dependency care, may be required. requirements; NICE guidance l In severe cases, debilitating illness Reassessment NICE’s (2017) guidance on IV fluid therapy or death. Regular reassessment of patients’ fluid indicates that the assessment of patients NICE (2017) recommends a bolus of therapy needs is essential. In those who should include: 500ml of crystalloid solution (containing require ongoing fluid therapy for three or l Physical examination; sodium in the range of 130-154mmol/L) more days, the enteral routes of adminis- l Observation of vital signs over time; over less than 15 minutes in patients tration should be considered (NICE, 2017). l Clinical presentation. requiring fluid resuscitation; this should Enteral routes reduce the need for IV access It also provides a set of parameters that be avoided for those who have any evi- and, in doing so, reduce the risks of may indicate that a patient needs fluid dence of pulmonary oedema as a result of ongoing IV therapy, such as catheter- resuscitation (Box 2). cardiac failure (Frost, 2015). This initial related infections. The parameters highlight the impor- fluid resuscitation should be followed by a tance of assessing patients’ fluid and elec- reassessment. If further fluid resuscitation Types of fluids trolyte balance. This involves ascertaining is required, then fluid boluses of 250- Crystalloids their history of fluid intake and any com- 500ml should be given. Patients needing Crystalloid solutions are isotonic plasma plaints of thirst. Consideration should also continuous boluses of up to 2L will need volume expanders that contain electro- be given to the likelihood of insensible further medical review. lytes. They can increase the circulatory fluid loss – for example, from altered bowel volume without altering the chemical bal- function such as diarrhoea, or injuries Routine maintenance ance in the vascular spaces. This is due to such as burns. Comorbidities such as dia- Routine maintenance fluids are needed in their isotonic properties, meaning their betes and cardiovascular disease can also patients who are at ongoing risk of fluid components are close to those of blood lead to fluid and electrolyte imbalances. loss. Reasons for this could be poor fluid circulating in the body. The monitoring of vital signs, along intake, recent surgery, bowel dysfunction Crystalloid solutions are mainly used to with the assessment of jugular venous and other comorbidities. Clinical exami- increase the intravascular volume when it pressure and observation for possible nation, investigations, vital signs is reduced. This reduction could be caused oedema and postural hypotension, can monitoring (including fluid balance and by haemorrhage, dehydration or loss of help identify abnormalities in patients’ weight measurements) can all help to fluid during surgery. fluid and electrolyte balance. The National determine a patient’s need for routine Early Warning Score (NEWS) and fluid bal- maintenance fluids. Box 2. Parameters for fluid ance and weight charts are essential tools. resuscitation Additional tests such as full blood count Replacement and urea and electrolytes can confirm the Ongoing assessment of patients’ fluid bal- l Systolic blood pressure: <100mmHg need for IV fluid therapy (NICE, 2017). ance is paramount. Assessment should l Heart rate: >90 beats per minute focus on: l Capillary refill: >2 seconds or The ‘5Rs’ of fluid resuscitation l Ensuring adequate hydration; peripheries cool to touch Resuscitation l Ensuring electrolyte balance; l Respiratory rate: >20 breaths To ascertain the fluid requirements of l Checking for any potential fluid overload. per minute patients who are acutely ill, an accurate When ensuring normal electrolyte l NEWS: ≥5 assessment is needed and should include parameters are met, it is particularly NEWS = National Early Warning Score the ABCDE – airway, breathing, circulation, important to consider the potassium Source: National Institute for Health and Care disability, exposure – approach (Frost, levels. Alterations in potassium – either Excellence (2017) 2015). It is also important to investigate the hypokalaemia or hyperkalaemia – can

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which can have a temporary negative effect Table 1. Comparative summary of crystalloid and on clotting times and coagulation (Marx colloid solutions and Schuerholz, 2010). Hypertension and Crystalloid solution Colloid sollution tachycardia, cardiac failure, and pulmonary and peripheral oedema are all poten- Half-life of 30-60 minutes Half-life of several hours or days tial side-effects of the excessive adminis- Three times the volume needed for Replaces fluid volume for volume tration of albumin, dextran or hetastarch replacement (Frost, 2015; Marx and Schuerholz, 2010). Excessive use can cause peripheral and Excessive use can precipitate cardiac pulmonary oedema failure Which fluid to administer? Crystalloids and colloids are plasma Molecules small enough to freely cross Molecules too large to cross capillary volume expanders used to increase a capillary walls, so less fluid remains in the walls, so fluid remains in intravascular depleted circulating volume. Over the intravascular spaces spaces for longer years they have been used separately or Inexpensive More expensive than crystalloids together to manage haemodynamic insta- Non-allergenic Risk of anaphylactic reactions bility. Both are suitable in fluid resuscitation, hypovolaemia, trauma, sepsis and Suitable for vegetarian or vegan patients Some preparations unsuitable for burns, and in the pre-, post- and peri-oper- vegetarian or vegan patients ative period. On occasion, they are used Source: Adapted from Pryke (2004) together (Frost, 2015). Colloids carry an increased risk of ana- phylaxis, are more expensive (Frost, 2015) The most frequently used crystalloid Hartmann’s solution) can be used (Joint and come with an added complication for fluid is sodium chloride 0.9%, more com- Formulary Committee, 2017; NICE, 2017). vegetarian or vegan patients, as some monly known as normal saline 0.9%. Other preparations contain gelatin (Joint Formu- crystalloid solutions are compound Crystalloid preparations lary Committee, 2017). However, colloid sodium lactate solutions (Ringer’s lactate containing glucose solutions are less likely to cause oedema solution, Hartmann’s solution) and glu- Normal saline with the addition of 5% than crystalloid solutions. Crystalloids are cose solutions (see ‘Preparations con- glucose is often used as a maintenance less expensive, carry little or no risk of ana- taining glucose’ below). Some crystalloid fluid. The main function of normal saline phylaxis, and pose no problem for vege- preparations containing additives such as is to replace lost water, as it distributes the tarian or vegan patients. However, evi- potassium or glucose are used in specific fluid throughout the body – thereby dence on any potential harmful effects of circumstances, for example, in hypoka- increasing total body water – but does not crystalloids is inconclusive. Table 1 laemia and hypoglycaemia (Joint Formu- restore intravascular volume. The loss of summarises the main characteristics of lary Committee, 2017). water without loss of electrolytes is rare, crysalloid and colloid solutions. but can be seen in patients with diabetes “The question of which insipidus and hypercalcaemia. The addi- What the literature says tional glucose acts as a source of energy The question of which plasma volume plasma volume expander for patients who are unable to take oral expander to use has long been controver- to use is controversial” foods and fluids (Joint Formulary Com- sial, resulting in several studies and sys- mittee, 2017). tematic reviews. In recent years, numerous Crystalloid solutions such as sodium Hyponatraemia is a side-effect of the research studies have been performed in chloride 0.9%, Ringer’s lactate and Hart- excessive use of 5% glucose. This is coun- different clinical situations to compare mann’s solution need to be administrated teracted by using mixed solutions, such as crystalloids and colloids and look at their in larger volumes than colloid solutions. 0.18% or 0.45% sodium chloride in 4% glu- advantages and disadvantages (Skytte As two-thirds of the infused volume will cose, or normal saline and 5% glucose Larsson et al, 2015; Jabaley and Dudaryk, move into the tissues, only the remaining (Frost, 2015). 2014; Yates et al, 2014; Burdett et al, 2012). third will stay in the intravascular space Jabaley and Dudaryk (2014) published a (NICE, 2017), leaving a diminished circu- Colloids study that compared the effects of crystal- lating volume in need of further fluid Colloids are gelatinous solutions that loids and colloids in trauma patients who administration. This increased volume can maintain a high osmotic pressure in the needed fluid resuscitation; as haemor- cause unwanted side-effects such as blood. Particles in the colloids are too large rhage is the second most common cause of oedema (NICE, 2017). to pass semi-permeable membranes such death from trauma, the need for haemody- Excessive amounts of infused sodium as capillary membranes, so colloids stay in namic stability and the maintenance of chloride 0.9% can produce hyperchlo- the intravascular spaces longer than crys- tissue and organ perfusion is essential. raemic acidosis due to its high chloride talloids. Examples of colloids are albumin, The study had limitations, including small content, leading to renal dysfunction, dextran, hydroxyethyl starch (or sample size, funding and reporting bias, resulting in a reduced glomerular filtra- hetastarch), Haemaccel and Gelofusine. and the results were inconclusive. tion rate (NICE, 2017; Clarke and Malecki- Caution should be used when adminis- Yates et al (2014) studied post-operative Ketchell, 2016; Myburgh and Mythen, tering hetastarch: exacerbated by the patients who were administered goal- 2013). To reduce this risk, compound haemodilution effects of fluid administra- directed fluid therapy. Their study demon- sodium lactate solutions (Ringer’s lactate/ tion, it can negatively affect platelet count, strated that colloids had no benefit over

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crystalloids in patients who had had colo- contraindications (Nursing and Midwifery rectal surgery and confirmed that using Council, 2015) of each. As with any medica- crystalloids was just as effective. tion, patients undergoing infusion Skytte Larsson et al (2015) compared the therapy should be closely monitored to effect of colloids and crystalloids on renal avoid fluid and electrolyte imbalances. perfusion, filtration and oxygenation after This may mean weighing them daily, as cardiac surgery. Maintenance of oxygen this is a reliable method of monitoring delivery and renal perfusion are particularly fluid status (NICE, 2017). NT important in the post-operative period to exclude the risk of acute kidney injury. References Skytte Larsson et al concluded that there Burdett E et al (2012) Perioperative buffered versus non-buffered fluid administration for was no difference in effectiveness between surgery in adults. Cochrane Database of colloid and crystalloid solutions in ensuring Systematic Reviews; 12: CD004089. adequate oxygen perfusion to the kidneys. Clarke D, Malecki-Ketchell A (2016) Nursing the Smorenberg and Groeneveld (2015) Acutely Ill Adult: Priorities in Assessment and studied the effects of fluid therapy on 42 made any difference to patients’ morbidity Management. London: Palgrave. septic and non-septic patients who had and mortality. This lack of definitive con- Frost P (2015) Intravenous fluid therapy in adult inpatients. British Medical Journal; 350: g7620. been assessed as hypovolaemic. Their clusions was due to the fact that the 28 Jabaley C, Dudaryk R (2014) Fluid resuscitation for study compared the urine output of those studies has been performed in different trauma patients: crystalloids versus colloids. receiving crystalloid and colloid solutions clinical settings. Current Anesthesiology Reports; 4: 3, 216-224. and determined that patients receiving Making use of these studies is problem- Joint Formulary Committee (2017) British National crystalloids had higher output volumes atic because they were conducted across Formulary 72. London: BMJ Group and than those receiving colloids. diverse clinical environments using dif- Pharmaceutical Press. Marx G, Schuerholz T (2010) Fluid-induced Perel et al (2013) performed a Cochrane ferent research methods, with alternative coagulopathy: does the type of fluid make a systematic review of 78 randomised con- hypotheses and, therefore, also with difference?Critical Care; 14: 1, 118. trolled trials comparing colloids and crys- potentially different outcomes. One size Moini J (2016) Anatomy and Physiology for Health talloids as plasma volume expanders in does not fit all, meaning the answer may Professionals. Burlington, MA: Jones and Bartlett patients who were critically ill. They con- not be the same for all clinical environ- Learning. cluded that colloids did not prove more ments: colloids may be better suited to Moore T, Cunningham S (2017) Clinical Skills for Nursing Practice. Abingdon: Routledge. effective than crystalloids in reducing the some clinical situations and crystalloids Myburgh JA, Mythen MG (2013) Resuscitation fluids. risk of death in patients with trauma or may be better in others. The New England Journal of Medicine; 369: 13, 1243. burns and in patients post-operatively. National Institute for Health and Care Excellence Orbegozo Cortés et al (2014) published a Implications for practice (2017) Intravenous Fluid Therapy in Adults in structured review on crystalloid solutions. To safely administer IV fluids, nurses and Hospital. Nice.org.uk/cg174 Nursing and Midwifery Council (2015) Standards for It included 28 studies that had investigated midwives need to ensure that: Medicines Management. Bit.ly/NMCMedsManage the physiological effects of crystalloid ● The patient is getting the right type of Orbegozo Cortés D et al (2014) Isotonic crystalloid solutions in several different clinical situa- fluid to meet their clinical need; solutions: a structured review of the literature. tions. The review concluded that crystal- ● The patient is adequately assessed British Journal of Anaesthesia; 112: 6, 968-981. loid solutions can have negative effects on before, during and after IV therapy; Peate I, Nair M (2016) Fundamentals of Anatomy and Physiology for Nursing and Healthcare electrolyte balance, coagulation and liver ● IV therapy is working for the patient Students. Chichester: Wiley Blackwell. and kidney function. It found that normal and, if this is not the case, oral or Perel P et al (2013) Colloids versus crystalloids for saline increased blood loss and the need enteral fluids are considered as an fluid resuscitation in critically ill patients. Cochrane for blood transfusion, and that Ringer’s alternative; Database of Systematic Reviews; 2: CD000567. lactate solution increased serum lactate ● Fluid balance and weight charts are Pryke S (2004) Advantages and disadvantages of levels. However, overall the studies were completed and reviewed; colloid and crystalloid fluids. Nursing Times; 100: 10, 32-33. inconclusive as to whether the changes ● Regular blood samples are taken, Skytte Larsson J et al (2015) Effects of acute brought about by crystalloid solutions checked and reviewed. plasma volume expansion on renal perfusion, Managers of staff administrating IV filtration, and oxygenation after cardiac surgery: a Nursing Times fluids need to ensure that: randomized study on crystalloid vs colloid. British Self-assessment ● Staff receive up-to-date education and Journal of Anaesthesia; 115: 5, 736-742. training, including on the ‘5Rs’ of fluid Smorenberg A, Groeneveld AB (2015) Diuretic Test your knowledge therapy; response to colloid and crystalloid fluid loading in critically ill patients. Journal of Nephrology; 28: 1, with Nursing Times ● Staff know what they are giving to 89-95. Self-assessment after reading this patients and why; Yates DR et al (2014) Crystalloid or colloid for article. If you score 80% or more, you ● Fluid therapy is delivered in accordance goal-directed fluid therapy in colorectal surgery. will receive a personalised certificate with the best use of resources. British Journal of Anaesthesia; 112: 2, 281-289. that you can download and store in Nurses and midwives administering IV your NT Portfolio as CPD or fluids should be aware of the variations For more on this topic go online... revalidation evidence. between the different fluid types as well as l Giving nutrition support to critically Visit nursingtimes.net/NTSAFluids any potential complications. They also ill adults to take the test. have a duty of care to understand the Bit.ly/NTNutrition

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