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

Excerpt

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 [8‐10]. …