RESUMO
BACKGROUND AND AIMS: Spinal anaesthesia induced hypotension (SAIH) and bradycardia may prove deleterious to both parturient and baby, hence vasopressors play a vital role in their management. Recent studies on norepinephrine as rescue vasopressor during subarachnoid block (SAB) enlighten its role for SAIH. This randomised double-blind trial was conducted to compare the effect of intermittent intravenous boluses of norepinephrine and frequently used mephentermine for management of SAIH in caesarean section (CS) to prove whether norepinephrine produces comparable effects or superior to mephentermine. METHODS: After approval from Institutional Ethics Committee and registration in Clinical Trials Registry India (CTRI/2019/06/019652), 256 parturients posted for elective CS under SAB were randomly allocated into Group-N and Group-M (n = 84) using chit system, who received boluses of intravenous norepinephrine 8µg and mephentermine 6mg for SAIH, respectively. Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), Response%, Apgar score and maternal complications were analysed. RESULTS: The changes in SBP and DBP were comparable in both the groups. It was significantly low after SAB compared to baseline and significantly high compared to 1st hypotensive value in both the groups throughout the study period (<0.0001). HR was comparable for initial 10 min, thereafter it was significantly high in Group-M (<0.0001) till 40 min. Response% after the first bolus was significantly high in Group-N (59.30n ± 29.21 vs 39.78 ± 25.6; P = <0.0001). CONCLUSION: Intravenous norepinephrine is better than mephentermine with respect to high response% and stable maternal HR although both are equally effective in maintaining blood pressure following SAIH during elective CS.
RESUMO
STATEMENT OF PROBLEM: The die contour can affect the emergence profile of prosthetic restorations. However, little information is available regarding the congruency between a stereolithographic (SLA) die and its corresponding natural tooth. PURPOSE: The purpose of this vitro study was to evaluate the shapes of SLA die in comparison with the subgingival contour of a prepared tooth to be restored with a ceramic crown. MATERIAL AND METHODS: Twenty extracted human teeth, 10 incisors, and 10 molars, were disinfected and mounted in a typodont model. The teeth were prepared for a ceramic restoration. Definitive impressions were made using an intraoral scanner from which 20 SLA casts with removable dies were fabricated. The removable dies and corresponding human teeth were digitized using a 3-dimensional desktop scanner and evaluated with computer-aided design software. The subgingival morphology with regard to angle, length, and volume at the buccolingual and mesiodistal surfaces and at zones A, B, C, and D were compared. Data were first analyzed with repeated measures analysis of variance (ANOVA), using locations (buccolingual and mesiodistal), zones (A, B, C, and D), and model type (SLA and Natural) as within-subject factors and tooth type (molar and incisor) as the between-subject factor. Post hoc analyses were performed to investigate the difference between natural teeth and corresponding SLA models, depending upon the interaction effect from the repeated measures ANOVA (α=.05). RESULTS: For angle analysis, the incisor group demonstrated a significant difference between the natural tooth and SLA die on the buccolingual surfaces (P<.05), whereas the molar group demonstrated a significant difference at the mesiodistal surfaces (P<.05). For the evaluation of length and volume, the incisor group showed significant differences in zone D on both the buccolingual (P<.05) and the mesiodistal (P<.05) surfaces. However, significant differences in zones C (P<.05) and D (P<.05) on the buccolingual surfaces and in all zones on the mesiodistal surfaces were observed in the molar group. CONCLUSIONS: For the comparison of angles, SLA dies did not replicate the subgingival contour of natural teeth on the buccolingual surfaces of the incisal groups. For the comparison of length and volume, SLA dies were more concave and did not replicate the subgingival contour of natural teeth in the incisal and molar groups.