Hemodynamics in thyrotoxicosis patients: inhalatedvs. total intravenous anesthesia

The aim. Comparison of hemodynamics indicators in patients with thyrotoxicosis syndrome during thy­­roid­ectomy when using inhalated (IA) or total intra­venous anesthesia (TIVA). Materials and methods. The study included 88 patients with thyrotoxicosis syndrome who underwent thyroidectomy. Depending on the type of basic anes­thesia, patients were divided into 2 groups: the group "balanced analgesia-sevoflurane" (BA-S) — 44 patients, the group "balanced analgesia-propofol" (BA-P) — 44 patients. The groups were equal in terms of anthro­pometric indicators, an assessment of the physical status by the American Association of Anesthetists, the duration of anesthesia and surgical intervention. The perioperative period was divided into stages: 1st stage — primary observation by the anesthesiologist; Stage 2 — patient was on the operating table and connected to the monitor; Stage 3 — Immediately after induction anesthesia and the trachea intubation; 4th stage — start of operation; 5th stage — removal of thyroid; 6th stage — after wound suturing (the end of surgery); 7th stage — in 24 hours after surgery. At each stage, a non-invasive blood pressure mea­surement (NIBP), systolic blood pressure (sBP), diastolic (dBP), mean BP (MBP), pulse pressure (PP), heart rate (HR)) was performed. Indicators of central hemo­dy­namics (cardiac output (CO), cardiac index (CI), total systemic vascular resistance (TVVR) were studied using the esCCO™ method (estimated continuous cardiac output). Results and discussion. Indicators of sBP, dBP, MBP, PP, and HR in the 1st stage did not have a statistically significant difference between groups. At the 2nd stage the MBP increased by 7.31 ± 0.01 %, 8.22 ± 0.02 %, respectively, in the groups BA-S and BA-P in comparison with the 1st stage. At the 3rd stage, after the induction anesthesia, were noted the lowest va­­luesof sBP, dBP, MBP, PP in both groups (significant difference according to (p< 0,001) the Wilcoxon cri­­terion with 1st and 2nd stages). At the same time, the significant difference (p < 0.01) by the Wilcoxon cri­­terion was noted between the absolute values of MBP, sBP, dBP, PP in the groups BA-S and BA-P. MBP at the 3rd stage was 77.57 ± 1.14 mmHg in the group BA-S and 69.12 ± 1.16 mmHg in the group BA-P. The decrease was 24.32 ± 0.81% for the group BA-S and 33.91 ± 0.93 % for the group BA-P (p < 0.01). However, absolute and relative hypotension was not noted in both groups. Having analyzed the parameters of central hemo­­dynamics, there was noted that the primary values of CO and CI,assessed by method esCCO, were close to the Doppler EchoCG and had Spirmen correlation rs = 0.83 for both groups, BA-S and BA-P (p < 0.05). Atthe 3rd stagea signi­ficant­decreaseof CO inbothgroups was observed, in BA-S groupwith a highermagnitude com­paredwith BA-P group, thedifferenceissignificant, p = 0.0237. At the 4th stage in the group BA-S was noted the statistically significant (p < 0.01) increaseof CO on 6.54 ± 0.13 % compared with the 3rd stage. At the same time the following CO reduction was noted in the BA-P group up to 5.14 ± 0.14 l/min (p = 0.606). At the next 5—7 stages, the stabilization of the indicators of CO, CI in both groups were noted, but significant differences were consistent between the 1st and 2nd stages. At the 7th stage, there were no statistical differences between the indicators of MBP, HR, sBP, dBP in both groups. Conclusions. Both, IA and TIVA, had negative impact on hemodynamics. The greatest dec­rease in hemo­dynamic indicators was observed at the 3rd stage (induction of anesthesia), in the TIVA group it was significantly lower than in IA group. There was a statistically significant difference between the IA and TIVA at this stage in values of sBP, dBP, MBP, PP, TSVR, CO. At the next 4—6 stages, the hemodynamic parame­ters stabilization was noted. No delayed negative influ­ence of general anesthesia was observed with use of sevoflurane or propofol at 6—7 stages. There is a strong correlation between values of CO, CI, and TSVR, obtained by DopplerEchoCG and esCCO method, rs = 0.83 for both groups BA-S and BA-P.