How we do it: Implementing change--a multi-centre audit of an evidence-based protocol on post-thyroidectomy calcium maintenance

A rare case of malignant fibrous histiocytoma (pleomorphic undifferentiated sarcoma NOS) of the vocal fold

Malignant fibrous histiocytoma, also known as pleomorphic undifferentiated sarcoma not otherwise specified, arises in numerous organs. The first-line treatment is complete excision of the mass, but in some cases postoperative chemo- and/or radiotherapy is recommended. Only a few cases of malignant fibrous histiocytoma of the vocal fold have been previously reported in the literature. We report a new case, which originated in the true vocal fold of a 65-year-old man. The mass was removed via CO2 laser excision with preservation of the vocal fold and without the need for further treatment. At 3 years of follow-up, the patient remained recurrence-free.

Post-thyroidectomy hypocalcemia: Impact on length of stay

Hypocalcemia is a recognized complication following thyroid surgery. Variability in the definition of hypocalcemia and different opinions on its management can lead to unnecessary patient morbidity and longer hospital stays as a result of inappropriate or untimely treatment. Therefore, we developed a management guideline for the recognition and treatment of post-thyroidectomy hypocalcemia, and we conducted a retrospective study to assess its impact on length of stay (LOS). Between April 1, 2007, and March 31, 2009, 29 adults had undergone a total or completion thyroidectomy at our large district general hospital. Of this group, postoperative hypocalcemia (defined as a serum calcium level of <2.00 mmol/L) developed in 13 patients (44.8%) during the first 3 postoperative days. Our guideline went into effect on July 1, 2009, and from that date through June 30, 2010, 18 more adults had undergone a total or completion thyroidectomy. Of that group, hypocalcemia developed in 7 patients (38.9%); the guideline was actually followed in 5 of these 7 cases (71.4%). In the preguideline group, the development of hypocalcemia increased the mean LOS from 2.0 days to 7.0 days (p < 0.001). The management of postoperative hypocalcemia in these cases was highly variable and was dictated by variations in practice rather than patient needs. In the postguideline group, postoperative hypocalcemia increased the mean LOS from 2.7 days to only 3.7 days (p = 0.07). While the difference between LOS in the two hypocalcemic groups did not reach statistical significance, we believe it merely reflects the relatively small number of patients rather than any lack of guideline efficacy. The implementation of a simple flowchart guideline for the management of postoperative hypocalcemia in our hospital has resulted in more uniform management and a reduced LOS.

Early prediction of oral calcium and vitamin D requirements in post-thyroidectomy hypocalcaemia

OBJECTIVE

To optimize and individualize post-thyroidectomy hypocalcemia management.

STUDY DESIGN

A multicenter prospective cohort study.

SETTING

Two tertiary care hospitals.

SUBJECTS AND METHODS

parathyroid hormone (PTH) was measured preoperatively, then at 1 and 6 hours after surgery. The required doses of calcium and vitamin D were defined as those maintaining the patients asymptomatic and their cCa ≥ 2 mmol/L. They were used as an endpoint in a generalized linear mixed effect model (GLIMMEX) aiming to identify the best predictors of these optimal required doses. Models were evaluated by goodness of fit and Receiver Operating Characteristic (ROC) curves.

RESULTS

One hundred and sixty-eight patients were analyzed; 85.1% were female, 49.3% had BMI > 30, and 64% had vitamin D deficiency. Post-thyroidectomy hypocalcemia was found in 25.6%, of whom 18 (41.9%) were symptomatic and received intravenous calcium. First hour percentage of drop in PTH correlated positively with the severity of hypocalcemia (P < .0001). The GLIMMIX prediction model for oral calcium requirement was based on first-hour percentage change from preoperative PTH level, preoperative actual PTH, BMI, and thyroid function. The same predictors were identified for vitamin D, except that thyroid function was replaced with vitamin D status. These factors were used to build predictive equations for calcium and vitamin D doses.

CONCLUSION

Our findings help to optimize management of post-thyroidectomy hypocalcemia by assisting in the early identification of those who are not at risk of hypocalcaemia and by guiding early effective management of those at risk. This may reduce complications and medical cost.

The timing of calcium measurements in helping to predict temporary and permanent hypocalcaemia in patients having completion and total thyroidectomies

INTRODUCTION

Postoperative hypocalaemia commonly occurs after extensive thyroid surgery and may require calcium and/or vitamin D supplements to alleviate or prevent the symptoms. In this study, we determined the risk factors for developing hypocalcaemia and whether early serum calcium levels can predict the development of or differentiate between temporary or permanent hypocalcaemia.

PATIENTS AND METHODS

A total of 162 patients who either had a completion or total thyroidectomy formed the basis of this prospective study. Serial serum calcium measurements were recorded as well as details of the operation, pathology, indications for surgery, number of parathyroids identified at operation and any complications.

RESULTS

Eighty-four (52%) patients did not develop hypocalcaemia but 69 (43%) were found to have temporary hypocalcaemia and 9 (5%) had permanent hypocalcaemia. Hypocalcaemia was more common after total than completion thyroidectomies and the identification of parathyroids at operation appears to have a significant adverse effect on outcome. The calcium levels measured on day 1 postoperatively and the slope (serum calcium levels of day 1 postoperative minus day of operation) were statistically significant in predicting the development of hypocalcaemia and possibly to differentiate between temporary or permanent hypocalcaemia.

DISCUSSION

Although almost half the patients having extensive thyroid surgery developed hypocalcaemia (as defined by any postoperative corrected serum calcium level of < 2.12 mmol/l) only 24% had a serum calcium of < 2.12 mmol/l associated with clinical symptoms of hypocalcaemia or a calcium level of < 2.0 mmol/l. Only 5% had persistent hypocalcaemia defined as requiring exogenous supplements at 6 months' postoperatively. Patients having a completion thyroidectomy appear to be less likely to develop hypocalcaemia perhaps as a result of any iatrogenic effects on the parathyroids at the first operation being reversed before the second operation. Identification and, therefore, exposure of parathyroids at operation may have an adverse effect on the blood supply to the glands affecting their function.

CONCLUSIONS

Serum calcium levels measured 6 hours' post-surgery and on day 1 postoperatively can be useful in predicting if the patient will develop hypocalcaemia and the slope may indicate whether the hypocalcaemia will be temporary or permanent. Patients with toxic goitres and those having a one-stage total thyroidectomy are most at risk of developing hypocalcaemia.