title: Better consenting for thyroidectomy: who has an increased risk of postoperative hypocalcaemia?
abstract: Hypocalcaemia is the most common complication following thyroidectomy. This study aimed to establish the factors associated with increased risk of hypocalcaemia on day 1 following thyroidectomy. All patients who underwent thyroidectomy under a single consultant during a 5-year period were included. A multivariate analysis was undertaken to ascertain which variables had the most effect on the risk of hypocalcaemia. A prognosis table was constructed to allow risk to be predicted for individual patients based on these factors. Included in the analysis were 210 procedures and 194 patients. Eighty-two percent of patients had no calcium derangement postoperatively. Fourteen point nine percent were categorised as early hypocalcaemia, 1 % had protracted hypocalcaemia and 2.1 % had permanent hypocalcaemia. For hemi-thyroidectomies 2.8 % had postoperative hypocalcaemia and 0.9 % had permanent hypocalcaemia. The multivariate analysis revealed total thyroidectomy (risk ratio 26.5, p < 0.0001), diabetes (risk ratio 4.8, p = 0.07) and thyrotoxicosis (risk ratio 3.1, p = 0.04) as statistically significant variables for early postoperative hypocalcaemia. Gender as an isolated factor did not reach significance but was included in the model. The p value for the model was p < 1 × 10-12. Total thyroidectomy increases risk of early hypocalcaemia when compared to hemithyroidectomy. Gender, diabetes and thyrotoxicosis were also been found to influence the risk. All of these factors are available pre-operatively and can therefore be used to predict a more specific risk for individual patients. It is hoped that this can lead to better informed consent, prevention and better resource allocation.
authors.affiliation: Betsi Cadwaladr University Healthboard, Clwyd, UK. drewharris@doctors.org.uk.|ENT Department, Glan Clwyd Hospital, Rhuddlan Road, Bodelwyddan, Rhyl, Denbighshire, LL18 5UJ, UK. drewharris@doctors.org.uk.
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Harris
authors.affiliation: Betsi Cadwaladr University Healthboard, Clwyd, UK.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Prades
authors.affiliation: Betsi Cadwaladr University Healthboard, Clwyd, UK.
authors.forename: Olena
authors.initials: O
authors.lastname: Tkachuk
authors.affiliation: Betsi Cadwaladr University Healthboard, Clwyd, UK.
authors.forename: Hisham
authors.initials: H
authors.lastname: Zeitoun
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D006801:Humans; D006996:Hypocalcemia / Q000209:etiology*; D007258:Informed Consent; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology*; D011379:Prognosis; D012306:Risk; D013959:Thyroid Diseases / Q000150:complications / Q000175:diagnosis / Q000601:surgery*; D013965:Thyroidectomy / Q000009:adverse effects*; D016896:Treatment Outcome
keywords: Hypocalcemia; Hypoparathyroidism; Informed consent; Postoperative complications; Risk; Thyroidectomy