Lin et al reported a nomogram for predicting delayed hyponatremia after transsphenoidal surgery for pituitary adenoma. The authors are from Fujian Medical University, Shanghai Donglei Brain Hospital and 900th Hospital Fuzhou in China.
Patient selection: status post transsphenoidal surgery for pituitary adenoma
Parameters:
(1) postoperative diabetes insipidus
(2) pituitary stalk deviation angle difference, from 0 to 65
(3) postoperative measurable pituitary stalk in mm, from 0 to 14
(4) blood sodium level on the second day after surgery in mmol/L, from 120 to 155
(5) diaphragmatic sella sinking depth in mm, from 0 to 20
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Postoperative Diabetes Insipidus
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Points
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|
no
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19
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|
yes
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0
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points for pituitary stalk deviation angle difference =
= 0.609 * (difference)
points for postoperative measurable pituitary stalk =
= 2.6 * (value)
points for blood sodium level on second day after surgery =
= 442.86 - (2.86 * (sodium)
points for diaphragmatic sella sinking depth =
= 1.22 * (depth)
total score =
= SUM(points for all of the parameters)
Interpretation:
• minimum score: 0
• maximum score: 219.4
value of X =
= (0.06197 * (score)) - 6.77
probability of delayed hyponatremia =
= 1 / (1 + EXP((-1) * X))
Performance:
• The area under the ROC curve is 0.81 for the training and 0.85 for the testing cohorts.
