Hypermanganesemia in total parenteral nutrition

Manganese is one of the trace elements that is routinely administered .0 TPN patients. The recommended daily IV dosage ranges from 0.15-0.8 mg. We have used 0.5 mg daily. Recent reports have suggested neurologic symptoms seen in some patients receiving HPN may be due to hypermanganesemia. Therefore we studied our HPN patients and some of our short-term in-patients receiving TPN to ascertain whether their dosage of manganese was optimal. Methods: Whole blood manganese levels were obtained by atomic absorptiometry. Results: The levels in 37 hospitalized, short-term patients prior to initiating TPN were all normal. 29 patients receiving TPN from 3 to 30 days ranged from 7-26 micrograms/ml (N < 24). Two patients had abnormal levels, at days 14 and 20 for one patient and at day 18 for the other. Ten of the 20 patients on HPN for 36 to 4868 days had elevated Mn levels, ranging from 28-53. Only one patient with hypermanganesemia had elevated liver tests (bilirubin and alkaline phosphatase). The patient with the highest level (53) had some vestibular symptoms attributed to aminoglycoside use and had increased signal density in the globus pallidus on Tl weighted images on MRI. A second patient with Mn levels twice normal had no neurologic symptoms, but had similar MRI findings. A third had some basal ganglia symptoms, confirmed by a neurologic evaluation, and very high Mn levels however she has not had an MRI. Conclusions: Hypermanganesemia is regularly seen in HPN patients receiving 0.5 mg manganese daily, and may have resulted in some neurologic damage in three patients. Hypermanganesemia is sometimes seen after a short course of TPN in in-patients, as early as 14 days. Since trace amounts of manganese are administered with other additives, we suggest that manganese should not be administered separately in TPN solutions, or should be administered in a curtailed dose, 0.1 mg daily. Patients should be monitored for hypermanganesemia if they receive Mn in their TPN for more than 30 days.