BackgroundContinuous vagal intraoperative neuromonitoring (CIONM) of the recurrent laryngeal nerve (RLN) may reduce the risk of RLN lesions during high-risk endocrine neck surgery such as operation for large goiter potentially requiring transsternal surgery, advanced thyroid cancer, and recurrence.MethodsFifty-five consecutive patients (41 female, median age 61 years, 87 nerves at risk) underwent high-risk endocrine neck surgery. CIONM was performed using the commercially available NIM-Response 3.0 nerve monitoring system with automatic periodic stimulation (APS) and matching endotracheal tube electrodes (Medtronic Inc.). All CIONM events (decreased amplitude/increased latency) were recorded.ResultsAPS malfunction occurred on three sides (3 %). A total of 138 CIONM events were registered on 61 sides. Of 138, 47 (34 %) events were assessed as imminent (13 events) or potentially imminent (34 events) lesions, whereas 91 (66 %) were classified as artifacts. Loss of signal was observed in seven patients. Actions to restore the CIONM baseline were undertaken in 58/138 (42 %) events with a median 60 s required per action. Four RLN palsies (3 transient, 1 permanent) occurred: one in case of CIONM malfunction, two sudden without any significant previous CIONM event, and one without any CIONM event. The APS vagus electrode led to temporary damage to the vagus nerve in two patients.ConclusionsCIONM may prevent RLN palsies by timely recognition of imminent nerve lesions. In high-risk endocrine neck surgery, CIONM may, however, be limited in its utility by system malfunction, direct harm to the vagus nerve, and particularly, inability to indicate RLN lesions ahead in time.

Background: After seven decades of levothyroxine (LT4) replacement therapy, dosage adjustment still takes several months. We have developed a decision aid tool (DAT) that models LT4 pharmacometrics and enables patient-tailored dosage. The aim of this was to speed up dosage adjustments for patients after total thyroidectomy. Methods: The DAT computer program was developed with a group of 46 patients post-thyroidectomy, and it was then applied in a prospective randomized multicenter validation trial in 145 unselected patients admitted for total thyroidectomy for goiter, differentiated thyroid cancer, or thyrotoxicosis. The LT4 dosage was adjusted after only two weeks, with or without application of the DAT, which calculated individual free thyroxine (fT4) targets based on four repeated measurements of fT4 and thyrotropin (TSH) levels. The individual TSH target was either <0.1, 0.1–0.5, or 0.5–2.0 mIU/L, depending on the diagnosis. Initial postoperative LT4 dosage was determined according to clinical routine without using algorithms. A simplified DAT with a population-based fT4 target was used for thyrotoxic patients who often went into surgery after prolonged TSH suppression. Subsequent LT4 adjustments were carried out every six weeks until target TSH was achieved. Results: When clinicians were guided by the DAT, 40% of patients with goiter and 59% of patients with cancer satisfied the narrow TSH targets eight weeks after surgery, as compared with only 0% and 19% of the controls, respectively. The TSH was within the normal range in 80% of DAT/goiter patients eight weeks after surgery as compared with 19% of controls. The DAT shortened the average dosage adjustment period by 58 days in the goiter group and 40 days in the cancer group. For thyrotoxic patients, application of the simplified DAT did not improve the dosage adjustment. Conclusions: Application of the DAT in combination with early postoperative TSH and fT4 monitoring offers a fast approach to LT4 dosage after total thyroidectomy for patients with goiter or differentiated thyroid cancer. Estimation of individual TSH-fT4 dynamics was crucial for the model to work, as removal of this feature in the applied model for thyrotoxic patients also removed the benefit of the DAT.

Mo aksklinikken Stavanger universitetssjukehusAnn-Elin Meling Stokland er lege i spesialisering i indremedisin og i endokrinologi. Forfa eren har fylt ut ICMJE-skjemaet og oppgir ingen interessekonflikter. Medisinsk avdelingHaugesund sjukehus Ida Kloster er lege i spesialisering i indremedisin og endokrinologi og er konstituert overlege. Forfa eren har fylt ut ICMJE-skjemaet og oppgir ingen interessekonflikter. Universitetet i Bergen og Medisinsk avdelingHaugesund sjukehus Bjørn Egil Vikse er dr.med., spesialist i indremedisin og i nyresykdommer, professor og klinikkoverlege. Forfa eren har fylt ut ICMJE-skjemaet og oppgir ingen interessekonflikter. Radiologisk avdeling Haugesund sjukehusArne Skjold er ph.d., spesialist i radiologi og overlege. Forfa eren har fylt ut ICMJE-skjemaet og oppgir ingen interessekonflikter.Avdeling for bryst-og endokrinkirurgi Haukeland universitetssjukehus Renate Vik er spesialist i generell kirurgi og i bryst-og endokrinkirurgi og er overlege. Forfa eren har fylt ut ICMJE-skjemaet og oppgir ingen interessekonflikter. Universitetet i Bergen og Medisinsk avdelingEn kvinne i 50-årene med magesmerter og alvorlig laktacidose | Tidsskrift for Den norske legeforening