Crystalloid fluid therapy: is the balance tipping towards balanced solutions?

Abstract

Intravenous saline solutions were first introduced into clinical practice in the Sunderland cholera epidemic of 1831 [1]. More than 150 years later, not only is 0.9 % saline the most commonly used intravenous fluid in critically ill patients, it is also the fluid that has been administered to the largest number of critically ill patients in randomised controlled trials [2,3]. It is cheap and readily available, and more than a million litres of intravenous 0.9 % saline are administered to patients around the world every day [1]; however, although it is widely known as 'normal saline', 0.9 % saline is neither normal nor physiological [4]. In fact, the concentration of chloride in 0.9 % saline is approximately 1.5 times that of normal plasma. Compared to low chloride solutions like Hartmann's, rapid infusion of 0.9 % saline results in acidosis due to reduced strong ion difference, reduced renal perfusion and glomerular filtration rate, a tendency towards reduced urinary output, and even a pronounced increase in body weight [5,6]. Recent data raise the possibility that administration of 0.9 % saline [7] may be harmful and suggest that using 'balanced' solutions with lower, more physiological, chloride concentrations than 0.9 % saline may be preferable [8][9][10].The relationship between the serum chloride concentration and outcome appears to be 'U-shaped' so that values outside of the normal physiological range are associated with an increased risk of death [11]. Positive fluid balance is also associated with an increased risk of death [12]. Because chloride loading and volume loading often occur together the relative contributions of chloride overload and volume overload to the apparent increased mortality risk are uncertain. In this issue of Intensive Care Medicine, Shaw and colleagues examine, among other things, the association between the 'volume-adjusted chloride load' and in-hospital mortality in more than 100,000 patients with tachycardia (heart rate over 90 bpm) and at least one other systemic inflammatory response syndrome (SIRS) criterion [13]. The purpose of this was to demonstrate the association between chloride administration and outcome independent of administered fluid volume. In doing so, Shaw and colleagues were able to demonstrate, for the first time, an association between increasing amounts of chloride administered during crystalloid resuscitation and increased in-hospital mortality which persisted after controlling for the total volume of fluid administered [13], raising the possibility that the chloride content of resuscitation fluids might be a modifiable risk factor for adverse outcomes.This study adds to previous data which demonstrated an association between the use of chloride-rich fluids and adverse outcomes compared to the use of balanced solutions in surgical patients [9] and patients with sepsis [10] and is consistent with a single centre, open label, beforeand-after period pilot study which showed that a strategy Intensive Care Med

Perioperative Plasma-Lyte use reduces the incidence of renal replacement therapy and hyperkalaemia following renal transplantation when compared with 0.9% saline: a retrospective cohort study

“…However, the association between the development and accentuation of AKI and 0.9% saline administration in critically ill patients remains controversial, with data both supporting and rejecting the hypothesis [ 19 , 20 ]. A recent study failed to demonstrate a benefit of Plasma-Lyte on the incidence of AKI, but the mean fluid volume administered was only 2 L in 24 h, considerably less than in our study [ 10 ].…”

“…A 0.9% saline solution remains the most widely used intravenous fluid during the perioperative period, but recent data has emerged questioning its safety [ 6–8 ]. A 0.9% saline solution has been shown to reduce renal cortical blood flow in healthy volunteers [ 9 ], and animal studies have suggested that sustained renal vasoconstriction is specifically related to hyperchloraemia [ 10 ]. The high chloride load in 0.9% saline has also been shown to induce hyperchloraemic acidosis [ 11 ], and this in turn has been associated with the development and accentuation of postoperative AKI [ 12 ].…”

Effect of a Buffered Crystalloid Solution vs Saline on Acute Kidney Injury Among Patients in the Intensive Care Unit

“…Additional considerations were that the sodium in Hartmann solution contains calcium and was therefore incompatible with blood products preserved in citrate-based anticoagulation solutions, and that Hartmann solution contains more chloride than PL-148. 14 The composition of the study fluids is shown in eTable 1 in Supplement 2. Participating ICUs were assigned to use blinded study fluid (either saline or buffered crystalloid) for alternating treatment blocks of 7 weeks, with the initial fluid determined by the study statistician using computer-generated randomization.…”

Emergency Management of Malignancy-Associated Hypercalcemia

“…Although some balanced solutions are calcium-free (i.e., Plasma-Lyte and Normosol-R), there are others that contain calcium such as Lactated Ringer's, which has a calcium concentration of 2 mmol/L (8 mg/dL) (Young & Joannidis, 2014). As long as the calcium concentration of the solution is less than the patient's serum calcium concentration, the solution can still be expected to lower calcium levels over …”