Utility of rapid intraoperative parathyroid hormone assay to predict severe postoperative hypocalcemia after reoperation for hyperparathyroidism.
BACKGROUND
Patients undergoing reoperative parathyroidectomy may develop severe transient or permanent hypoparathyroidism. This study's purpose was to determine the utility of intraoperative parathyroid hormone (IO-PTH) values in predicting the development of severe hypocalcemia for patients undergoing reoperation for primary hyperparathyroidism.


METHODS
Between March 1999 and October 2001, 68 patients with persistent or recurrent hyperparathyroidism underwent reoperation using IO-PTH measurements. The maximum percent decrease and lowest actual PTH value obtained at surgery were compared to determine any correlation with the development of postoperative hypocalcemia requiring supplementation.


RESULTS
Of 68 patients, 25 required calcium and calcitriol postoperatively and 43 did not. There was a significant difference between the 2 groups with respect to lowest IO-PTH value (18.4 +/- 2.6 vs 28.0 +/- 3.9 pg/mL; P =.02), percent decrease in IO-PTH (89% +/- 1% vs 80% +/- 3%; P =.03), and lowest postoperative ionized calcium (1.06 +/- 0.01 vs 1.19 +/- 0.01 mmol/L; P <.001). A percent decrease in IO-PTH of 84% or greater was found to be predictive of patients experiencing hypocalcemia requiring supplementation with a positive predictive value of 46% and a negative predictive value of 82%.


CONCLUSIONS
Although a maximum percent decrease in IO-PTH of 84% or greater was associated with an increased incidence of postoperative hypocalcemia requiring supplementation in the 68-patient cohort, on further analysis the association was significant only for patients with multiglandular disease and not those with single adenomas. This value may be useful for identifying patients who will need closer postoperative monitoring or prophylactic supplementation.
Elaraj
Dina M
DM
Surgery Branch, National Cancer Institute, Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases/NIH, Building 10, Room 2B07, 9000 Rockville Pike, Bethesda, MD 20892, USA.
Remaley
Alan T
AT
Simonds
William F
WF
Skarulis
Monica C
MC
Libutti
Steven K
SK
Bartlett
David L
DL
Venzon
David J
DJ
Marx
Stephen J
SJ
Alexander
H Richard
HR
D000328:Adult; D000368:Aged; D002118:Calcium / Q000097:blood; D005260:Female; D006801:Humans; D006961:Hyperparathyroidism / Q000097:blood / Q000175:diagnosis* / Q000601:surgery*; D006996:Hypocalcemia / Q000097:blood / Q000175:diagnosis*; D007430:Intraoperative Care; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000032:analysis* / Q000097:blood; D016105:Parathyroidectomy; D011183:Postoperative Complications / Q000097:blood / Q000175:diagnosis; D011237:Predictive Value of Tests; D011379:Prognosis; D012086:Reoperation; D012720:Severity of Illness Index; D013997:Time Factors
D010281:Parathyroid Hormone; D002118:Calcium