Background: Iodine is an essential element for the synthesis of thyroid hormones. Therefore, a reliable marker of iodine supply is important. Iodine is predominantly excreted via kidneys, but also via salivary glands. Our aim was to introduce a new and simple method for determination of salivary iodine concentration (SLIC).
Materials and methods: Self-prepared chemicals and standards for Sandell-Kolthoff reaction on microplate with ammonium peroxydisulfate (AP) in the range 0-400 µg/L were used. Suitability of water-based standards (WBS) and artificial saliva-based standards (ASS) for standard curve were tested. We followed standards for method validation, defined concentration of used AP and compared our results with Inductively Coupled Plasma Mass Spectrometry (ICP-MS).
Results: WBS gave more reliable results than ASS as an underestimation of iodine concentration was found for ASS. LoB was 6.5 µg/L, LoD 12.0 µg/L, therefore analytical range was 12-400 µg/L. Intra- and inter-assay imprecisions at iodine concentrations, namely 20, 100, 165, and 350 µg/L were 18.4, 5.1, 5.7, and 2.8%, respectively, and 20.7, 6.7, 5.1, and 4.3%, respectively. Suitable molarity of AP was 1.0 mol/L and showed no difference to 1.5 mol/L (P values for samples with concentration 40, 100, and 150 µg/L, were 0.761, 0.085, and 0.275, respectively), whereas there was a significant change using 0.5 mol/L (P<0.001). Saliva samples could be diluted up to 1:8. There was no interference of thiocyanate and caffeine up to 193.5 mg/L. Our original method was comparable to ICP-MS. Spaerman coefficient was 0.989 (95% CI: 0.984-0.993).
Conclusions: The new method for SLIC determination is in excellent agreement with ICP-MS and easy-to-use.
Background: The aim of the study was to provide insight into the influence of the COVID-19 on the frequency and characteristics of urgent and emergent tracheostomies (TS), comparing data collected both before and during the pandemic. Our two hypotheses were that during COVID-19, more TS were performed in the emergent setting and that during COVID-19 more TS were performed under general anaesthesia.
Patients and methods: The research was retrospective. The study period included the two years before and after the COVID-19 outbreak in Slovenia. Forty-one patients in each period met the inclusion criteria. Their medical charts were reviewed. The anamnestic, clinical, surgical and anaesthesiological data were collected. The two groups of patients from corresponding time periods were statistically compared.
Results: Predominantly men required the surgical resolution of acute upper airway obstruction (76% of patients). The causes for acute respiratory distress included head and neck cancer (62%), infections (20%), vocal cord paralysis (16%), and stenosis (2%). There were no statistically significant differences either in the (emergent/urgent) setting of TS or in the type of anaesthesia used. Both hypotheses were rejected. A statistically significant rise in use of the C-MAC laryngoscope during COVID-19 (from 3% to 15%) was reported.
Conclusions: The outbreak of COVID-19 did not have a statistically significant effect on the frequency of performing emergent and urgent tracheostomies nor on the use of general or local anaesthesia. It did, however, require a change of intubation technique. Consequently, a significant rise in the use of the C-MAC laryngoscope was noted.

