INTRODUCTION
Mannitol is an inert, undissociated six-carbon polyhydric alcohol. It is an osmotic diuretic. Mannitol is used during cardiac surgery as it improves renal blood flow, minimizes extra vascular fluid shifts and reduces positive fluid balance.
METHODS
A retrospective analysis was performed on the usage of mannitol during cardiopulmonary bypass. Mannitol was not used as a constituent of the prime, however was administered during cardiopulmonary bypass, at the discretion of the perfusionist, to augment diuresis and to minimize fluid movement to the extra vascular space. Data was collected from sixty-five consecutive patients who underwent routine cardiopulmonary bypass procedures. The patients were divided into two groups. Group A did not receive any mannitol during the surgery; Group B received 0.25 g/kg body weight mannitol during surgery. The parameters analyzed were age, pre operative hemoglobin, weight, renal function, intra operative hemoglobin, bypass time, urine output, volume added during bypass and the fluid balance. Statistical analysis was performed with SPSS for windows V 13.
RESULTS
32 patients (group A) did not receive any mannitol. 33 patients (group B) received mannitol.The demographics show that the two groups were similar in all respects except for the bypass time (p < 0.05), which was significantly longer in group B (88.1 vs. 109.8 mins).
| Group A (no Mann) | Group B (Mann) | p Value | |
|---|---|---|---|
| Age | 64.9 (±12.5) | 69.4 (±12) | 0.14 |
| Hb (pre-op) | 134 (±18.4) | 137.8 (±17.4) | 0.40 |
| Weight | 79.5 (±14.4) | 78.6 (±14.6) | 0.79 |
| Urea | 7.23 (±2.9) | 9.2 (±12.1) | 0.36 |
| Creatinine | 89.4 (±31.8) | 91.8 (±28.8) | 0.76 |
| Fluid balance | 3131.3 (±840.0) | 3341.9 (±1064.4) | 0.38 |
| Bypass time | 88.09 (±23.2) | 109.8 (±41.9) | 0.01 |
| Urine output | 725 (±467.3) | 806.7 (±516) | 0.51 |
| Hb (bypass) | 76.1 (±15.3) | 77.7 (±12.1) | 0.63 |
CONCLUSION
The results of the review showed no significant difference in fluid balance and urine out put with the addition of mannitol. There was a trend for increased urine output in patients with prolonged bypass time. A prospective randomized control trial with larger patient group and addition of mannitol either in the prime or at a discrete time during bypass to reduce the variability between the groups is recommended.