Hemolysis falsely decreases intraoperative parathyroid hormone levels.
BACKGROUND
Intraoperative parathyroid hormone (IOPTH) measurement is used to confirm biochemical cure during parathyroidectomy. Falsely decreased IOPTH measurements could result in false-negative or false-positive results and lead to failed parathyroidectomy or unnecessary additional exploration.


METHODS
The records of all patients who underwent parathyroidectomy with IOPTH between May and August 2007 were retrospectively reviewed, and the frequency of hemolysis of IOPTH samples was determined. Separately, 10 split-samples were hemolyzed using the freeze-thaw technique.


RESULTS
Forty-seven patients underwent parathyroidectomy, and 226 IOPTH samples were sent. Seventeen (7.5%) specimens from 9 (18.8%) patients were hemolyzed. In 8 split-samples, the range of decrease caused by hemolysis was 24.5% to 53.8% compared with nonhemolyzed controls.


CONCLUSIONS
Hemolysis of IOPTH samples occurs commonly and falsely decreases IOPTH levels. Unrecognized hemolysis in pre-excision specimens could result in false-negative IOPTH results and lead to unnecessary continued exploration. Unrecognized hemolysis in postexcision specimens could lead to false-positive IOPTH results and lead to failed parathyroidectomy and the need for reoperation. Thus, hemolysis may be an easily preventable cause of erroneous IOPTH measurements.
Moalem
Jacob
J
University of California, San Francisco, CA, USA. jacob_moalem@urmc.rochester.edu
Ruan
Daniel T
DT
Farkas
Rachel L
RL
Shen
Wen T
WT
Gosnell
Jessica E
JE
Miller
Steve
S
Duh
Quan-Yang
QY
Clark
Orlo H
OH
Kebebew
Electron
E
D000368:Aged; D003951:Diagnostic Errors; D005260:Female; D006461:Hemolysis; D006801:Humans; D006961:Hyperparathyroidism / Q000097:blood* / Q000601:surgery*; D007430:Intraoperative Care; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood*; D016105:Parathyroidectomy; D012189:Retrospective Studies; D013048:Specimen Handling
D010281:Parathyroid Hormone