The influence of mannitol on renal function during and after open-heart surgery

Abstract

Mannitol is often included in the priming solution of the heart-lung machine used during cardiopulmonary bypass (CPB). This study was set up to evaluate the effect of different doses of mannitol on human patients. Patients receiving 10 g of mannitol (n = 18) had an increased diuresis only during the bypass period (mean time = 87 min) when compared with a control group (n = 19) who did not receive mannitol. Patients receiving 20 g of mannitol (n = 19) had a significantly greater diuresis than both the control group and the 10 g group and the diuresis continued on throughout the immediate postbypass period (total mean time approximately 3 h). Patients receiving 30 g of mannitol (n = 20) also had a significantly greater diuresis that continued on during the first hour in the intensive care unit (ICU) (total mean time approximately 4 h). After 6 h in the ICU, all three groups of mannitol-treated patients equally demonstrated a trend towards an increased diuresis over the control group, which became a significant increase by 12 h in the ICU (p = 0.001) despite indications that the mannitol had been cleared from the body. These results suggest that there is an improvement of renal function post-CPB if mannitol is included in the CPB prime which may be due to an amelioration of the ischaemic effects of bypass on the kidneys.

AKI Associated with Cardiac Surgery

“…Despite this, the renal outcomes associated with the use of mannitol in cardiac surgery are mixed (210)(211)(212)(213). There are some data suggesting that atrial natriuretic peptide (214) and B-type natriuretic peptide (215) may be of benefit in patients undergoing cardiac surgery.…”

The effect of mannitol on renal function after cardiopulmonary bypass in patients with established renal dysfunction*

“…Nearly 40% of cardiac units in the UK use mannitol as a component of the bypass pump prime [7]. Mannitol is freely filtered by the glomeruli, with a plasma half-life of 2.5 h [8], and <7% is reabsorbed [9], resulting in an increase in the osmotic pressure of the glomerular filtrate to produce a diuresis. The osmotic effect also reduces glomerular and tubular oedema, helping to restore glomerular blood flow and aid removal of intraluminal obstructions [8].…”

“…Mannitol is freely filtered by the glomeruli, with a plasma half-life of 2.5 h [8], and <7% is reabsorbed [9], resulting in an increase in the osmotic pressure of the glomerular filtrate to produce a diuresis. The osmotic effect also reduces glomerular and tubular oedema, helping to restore glomerular blood flow and aid removal of intraluminal obstructions [8]. Mannitol increases renal blood flow [9,10] and may also scavenge oxygen free radicals, which reduces injury to the renal brush border membrane [10].…”

Comparison of Early Results Between on-Pump and Off-Pump Cabg in Patients With Preoperative Mild to Moderate Renal Impairment.

“…However, several other studies did not confirm these findings, and the potential role of mannitol remains unclear . In fact, Carcoana et al [28] showed an increased urinary excretion of ß-2 microglobulin in patients who received mannitol and dopamine, suggestive of increased tubular injury in this group. Sirivella et al randomly assigned 100 patients with postoperative oliguric or anuric renal failure to therapy with either intermittent doses of loop diuretics or a continuous infusion of mannitol, furosemide, and dopamine (2 mg/kg per min).…”