Does preoperative 25-hydroxyvitamin D status significantly affect the calcium kinetics after total thyroidectomy?

BACKGROUND: Although previous studies have suggested that low preoperative 25-hydroxyvitamin D (25-OHD) is a risk factor for hypocalcemia after total thyroidectomy, the impact of preoperative 25-OHD on calcium (Ca)/parathyroid hormone (PTH) kinetics in the immediate postoperative period remains unclear. The study compared the postoperative Ca/PTH kinetics between different preoperative 25-OHD levels. PATIENTS: A total of 281 patients who underwent a total thyroidectomy were analyzed. Serum Ca was measured preoperatively within 1 h after surgery (Ca-D0) and on the following morning (Ca-D1). Preoperative 25-OHD was also measured after overnight fasting while postoperative PTH was checked at skin closure on day 0 (PTH-D0) and on the following morning on day 1 (PTH-D1). The Ca/PTH kinetics were compared between three groups (group I: preoperative 25-OHD < 10 ng/mL; group II: 25-OHD = 10-20 ng/mL; group III: 25-OHD > 20 ng/mL). RESULTS: Group I had significantly lower preoperative Ca (p = 0.016) and Ca-D0 (p = 0.036) but higher PTH-D1 (p = 0.015) than groups II and III. PTH-D0, Ca-D1, and the rate of clinically significant hypocalcemia were similar in the three groups. Group I had a significantly smaller Ca drop (-0.02 vs. 0.01 and 0.02 mmol/L, p = 0.011) and a tendency for a significantly smaller PTH drop (0.4 vs. 0.5 and 1.0 pmol/L, p = 0.073) than groups II and III. PTH-D1 (OR = 1.550) and 25-OHD (OR = 0.958) were independent factors for Ca drop from day 0 to day 1. CONCLUSIONS: Although group I began with lower serum Ca, those patients tended to have a greater PTH response to Ca drop and so preoperative 25-OHD did not significantly affect the overall Ca kinetics from preoperative to day 1.

Do low preoperative vitamin D levels reduce the accuracy of quick parathyroid hormone in predicting postthyroidectomy hypocalcemia?

BACKGROUND: Although some studies have suggested that low preoperative 25-hydroxyvitamin D (25-OHD) levels may increase the risk of hypocalcemia and decrease the accuracy of single quick parathyroid hormone in predicting hypocalcemia after total thyroidectomy, the literature remains scarce and inconsistent. Our study aimed to address these issues. METHODS: Of the 281 consecutive patients who underwent a total/completion total thyroidectomy, 244 (86.8%) did not require any oral calcium and/or calcitriol supplements (group 1), while 37 (13.2%) did (group 2) at hospital discharge. 25-OHD level was checked 1 day before surgery, and postoperative quick parathyroid hormone (PTH) was checked at skin closure (PTH-SC). Postoperative serum calcium was checked regularly. Hypocalcemia was defined by the presence of symptoms or adjusted calcium of <1.90 mmol/L. Significant factors for hypocalcemia were determined by univariate and multivariate analyses. The accuracy of PTH-SC in predicting hypocalcemia was measured by area under a receiver operating characteristic curve (AUC), and the AUC of PTH-SC was compared between patients with preoperative 25-OHD <15 and ≥15 ng/mL via bootstrapping. RESULTS: Preoperative 25-OHD level was not significantly different between groups 1 and 2 (13.1 vs. 12.5 ng/mL, p = 0.175). After adjusting for other significant factors, PTH-SC (odds ratio 2.49, 95% confidence interval 1.52-4.07, p < 0.001) and parathyroid autotransplantation (odds ratio 3.23, 95% confidence interval 1.22-8.60, p = 0.019) were the two independent factors for hypocalcemia. The AUC of PTH-SC was similar between those with 25-OHD <15 and ≥15 ng/mL (0.880 vs. 0.850, p = 0.61) CONCLUSIONS: Low 25-OHD was not a significant factor for hypocalcemia and did not lower the accuracy of quick PTH in predicting postthyroidectomy hypocalcemia.

Remnant left liver size and recovery of living right liver donors.

PURPOSE: Living donor liver transplantation is a realistic life-saving treatment in regions where deceased donor organs are scarce. The minimum remnant left liver volume (RLLV) requirement for donor right hepatectomy (DRH) varies in different programs of living donor liver transplantation. The present study aimed to determine how significant the RLLV is in the recovery of right liver donors. METHOD: A total of 349 consecutive donors who underwent DRH including the middle hepatic vein were divided into nine groups according to the percentage of the RLLV. The peak and recovery of the serum bilirubin level and prothrombin time (PT) in the 1st week after operation and postoperative complications were studied. RESULTS: The median RLLV was 35.5 (27-49.5) %. Postoperative peak serum bilirubin was highest [74 (25-133) µmol/L] in the group with RLLVs <30 %. This group also had the highest peak PT [18.9 (15.4-24.4) s], although results were similar between groups. Total bilirubin peaked on postoperative days 1-2 in groups with RLLVs ≥35 %. In groups with RLLVs <35 %, total bilirubin peaked on day 3. PT took 1-2 days to peak and nearly approached preoperative values on day 7 in all groups. Complication rates ranged from 0 to 75 %. The rates of complications of Clavien-Dindo grade 3 or above ranged from 0 to 3.8 %. Postoperative peak bilirubin was associated with severe complications (p = 0.031). Age, postoperative peak PT, and RLLV were independent risk factors for prolonged hospital stay. CONCLUSION: There was a demonstrable trend of slower recovery of liver function in donors with smaller RLLVs.