Israel Medical Association Journal

Background: Hypocalcaemia following thyroid and parathyroid surgery is a well-recognized potential complication.

Objectives: To determine the utility of intraoperative quick parathormone assay in predicting severe hypocalcemia development following parathyroidectomy for a single-gland adenoma causing primary hyperparathyroidism.

Methods: A retrospective cohort study was performed. IO-QPTH[1] values were measured at time 0 (T0) before incision, and 10 (T10) and 30 minutes (T30) following excision of the hyperfunctioning gland. Percent decrease in IO-QPTH at 10 minutes (T10), maximum percent decrease of IO-QPTH value, and lowest actual IO-QPTH value obtained at surgery were used to determine any correlation with the development of postoperative hypocalcemia requiring treatment.

Results: Percent decrease in IO-QPTH at 10 minutes, maximum percent decrease in IO-QPTH and lowest IO-QPTH value did not correlate with the lowest postoperative calcium levels measured 18 hours after surgery (r = 0.017, P = 0.860 r = 0.018, P = 0.850 and r = 0.002, P = 0.985 respectively). For the purposes of our analysis, patients were subdivided into three groups. Group 1 comprised 68 patients with normal calcium levels (serum Ca 8.6¨C10.3 mg/dl) Group 2 had 28 patients with hypocalcemia (8.1¨C8.6 mg/dl) Group 3 included 12 patients with severe hypocalcemia (calcium level ¡Ü 8.0 mg/dl) requiring calcium supplementation due to symptoms of hypocalcemia. There was no difference between the three groups in the lowest IO-QPTH value (P = 0.378), percent decrease in IO-QPTH (P = 0.305) and maximum percent decrease in IO-QPTH (P = 0.142).

Conclusions: IO-QPTH evaluation was not useful in predicting the group of patients susceptible to develop severe postoperative hypocalcemia.  

[1] IO-QPTH = intraoperative quick parathormone

Background: Among the various new technologies in the field of parathyroid surgery are intraoperative quick parathormone measurements.

Objectives: To evaluate the contribution of QPTH[1] measurements during parathyroidectomy to the achievement of higher success rates. 

Methods: QPTH assay using Immulite Turbo Intact PTH[2] was measured in 32 patients undergoing parathyroidectomy: 30 for primary and 2 for secondary hyperparathyroidism.  QPTH levels were measured at time 0 minutes (before incision) and at 10, 20, and 30 minutes after excision of the hyperfunctioning gland.  Only a drop of 60% or more from the 0’ level was considered to be a positive result.

Results: The mean QPTH level at time 0’ for PHPT[3] patients was 38.12 ± 25.15 pmol/L (range 9.1–118 pmol/L).  At 10 minutes post-excision of the hyperfunctioning gland (or glands), QPTH dropped by a mean of 73.80% to 9.89 ± 18.78 pmol/L. 

Conclusions: Intraoperative QPTH level measurement is helpful in parathyroid surgery.  A drop of 60% or more from 0’ level indicates a successful procedure, and further exploration should be avoided.