Serum magnesium level and post-operative pain sensation in patients after tonsillectomy

Objective: The tonsillectomy is known as the standard procedure with the most severe problems in post-operative pain management in the field of ENT. Could there be a correlation between the individual pain sensation after tonsillectomy and the serum magnesium level of the affected patients? Material and methods: Between July and December 2013 81 consecutive tonsillectomy patients (37 male, 44 female) of the ENT clinic at Nordhausen were asked to specify their postoperative pain on a visual analogue scale (VAS, 0 - 10) twice a day over a maximal span of a week. The magnesium serum level was measured pre-operatively. All patients received a standard analgesic treatment with metamizol or paracetamol. Results: Regarding to the serum level our population showed a normal distribution -12 patients < 0.80 mmol/L (group A), 17 patients 0.80 - 0.85 mmol/L (group B), 28 patients 0.85 - 0.90 mmol/L (group C), 16 patients 0.90 - 0.95 mmol/L (group D), and 8 patients > 0.95 mmol/L (group E). The mean VAS of group A was 2 +/- 1.871 points, of group B 0.956 +/- 1.016 points, of group C 1.688 +/- 1.595, of group D 0.906 +/- 1.186 points, and of group E 1.344 +/- 2.066 points. The increasing of VAS in group A becomes significant between day 4 and 6 after operation (p = 0.01), when the first wound debris dissolves. Conclusion: Our data points show a particular pain sensibility in the neuropathic range of patients, whose serum magnesium level is decreased. The value of magnesium as a co-analgesic drug should be tested for this group.