Mannitol Contraindications
Mannitol is absolutely contraindicated in patients with well-established anuria due to severe renal disease, severe pulmonary congestion or frank pulmonary edema, active intracranial bleeding (except during craniotomy), severe dehydration, progressive heart failure or pulmonary congestion after mannitol initiation, and known hypersensitivity to mannitol. 1
Absolute Contraindications
The FDA-approved labeling explicitly lists the following as contraindications 1:
Well-established anuria due to severe renal disease - Mannitol requires functional kidneys for excretion; once renal function is impaired, mannitol accumulates causing cellular dehydration and fluid shifts into the intravascular space 2
Severe pulmonary congestion or frank pulmonary edema - Mannitol initially expands intravascular volume before diuresis occurs, which can precipitate or worsen pulmonary edema 1
Active intracranial bleeding except during craniotomy - Mannitol may increase cerebral blood flow and worsen bleeding risk 1
Severe dehydration - Mannitol causes further water loss and can intensify hypovolemia 1
Progressive heart failure or pulmonary congestion after mannitol therapy has been started - This indicates the patient cannot tolerate the volume expansion effects 1
Known hypersensitivity to mannitol 1
Critical Clinical Situations Requiring Extreme Caution
Oligoanuria in Rhabdomyolysis
Mannitol is contraindicated in patients with oligoanuria, even in the setting of rhabdomyolysis with markedly elevated creatine kinase levels. The KDOQI Work Group states that osmotic diuretics like mannitol may only potentially benefit patients with CK >30,000 U/L, but this benefit remains undefined and mannitol should be administered with extreme caution and is specifically contraindicated in oligoanuric patients 3.
Obstructive Uropathy and Hypovolemia
Loop diuretics or mannitol should not be used in patients with concomitant obstructive uropathy or hypovolemia when treating tumor lysis syndrome 4.
Renal Protection
The American Heart Association explicitly advises against using furosemide, mannitol, or dopamine solely for the purpose of renal protection in descending aortic repairs. 4, 5 These agents have not been demonstrated to provide renal protection during such procedures 4.
High-Risk Populations Requiring Monitoring
While not absolute contraindications, the following conditions significantly increase risk 1:
Pre-existing renal disease - Mannitol accumulation occurs when renal function is impaired, leading to severe dilutional hyponatremia with hyperosmolality and potential acute renal failure 2, 6
Congestive heart failure - Accumulation of mannitol may intensify existing or latent heart failure 1
Diabetes mellitus - History of diabetes is an independent predictor of mannitol-induced acute renal insufficiency 7, 8
Coronary artery disease and hypertension - These chronic conditions increase risk of renal complications 8
Patients on nephrotoxic drugs - Concomitant use of nephrotoxic drugs (especially cyclosporine) or other diuretics with mannitol should be avoided as they increase risk of renal failure 1, 6
Common Pitfalls
Do not use mannitol in hemodialysis patients for volume management - appropriate ultrafiltration techniques and dietary sodium restriction are preferred, as recommended by the American Journal of Kidney Diseases 5. Mannitol causes significant fluid and electrolyte imbalances, particularly hypernatremia, in patients with impaired renal function 5.
Avoid using mannitol before adequate volume resuscitation - In rhabdomyolysis, diuresis should only be considered after adequate volume expansion has been achieved 3.