1.
The impact of propranolol on nitric oxide and total antioxidant capacity in patients with resistant hypertension-evidence from the APPROPRIATE trial.
Ranasinghe, HN, Fernando, N, Handunnetti, S, Weeratunga, PN, Katulanda, P, Rajapakse, S, Galappatthy, P, Constantine, GR
BMC research notes. 2020;(1):228
Abstract
OBJECTIVES The objective was to assess the effect of propranolol on oxidative stress and anti-oxidant potential in patients with resistant hypertension as a secondary analysis of the APPROPRIATE trial. This randomized double blinded clinical trial recruited patients with resistant hypertension and allocated forty patients to propranolol and placebo in 1:1 ratio. The pro-oxidant state (nitrate and nitrite) was assessed using modified Griess assay. The total anti-oxidant capacity was measured using ABTS assay. RESULTS Analysis was performed for 18 patients from the propranolol group and 15 from the placebo group. A decline in end point ambulatory blood pressure (p = 0.031) and greater mean reduction in office SBP (29.7 ± 13.0 mmHg, p = 0.021) was noted in the propranolol arm. Nitrate and nitrite levels were lower at the end of a 90 day follow up period in both arms, with a greater mean reduction with propranolol. A significant increase in the AOC was noted in both arms with higher incremental value with Propranolol. The findings of this study do not demonstrate a statistically significant effect of propranolol on the oxidative stress/antioxidant balance in patients with resistant hypertension. The observed trends merit further evaluation.
2.
Association of Weight-Adjusted Caffeine and β-Blocker Use With Ophthalmology Fellow Performance During Simulated Vitreoretinal Microsurgery.
Roizenblatt, M, Dias Gomes Barrios Marin, V, Grupenmacher, AT, Muralha, F, Faber, J, Jiramongkolchai, K, Gehlbach, PL, Farah, ME, Belfort, R, Maia, M
JAMA ophthalmology. 2020;(8):819-825
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Abstract
IMPORTANCE Vitreoretinal surgery can be technically challenging and is limited by physiologic characteristics of the surgeon. Factors that improve accuracy and precision of the vitreoretinal surgeon are invaluable to surgical performance. OBJECTIVES To establish weight-adjusted cutoffs for caffeine and β-blocker (propranolol) intake and to determine their interactions in association with the performance of novice vitreoretinal microsurgeons. DESIGN, SETTINGS, AND PARTICIPANTS This single-blind cross-sectional study of 15 vitreoretinal surgeons who had less than 2 years of surgical experience was conducted from September 19, 2018, to September 25, 2019, at a dry-laboratory setting. Five simulations were performed daily for 2 days. On day 1, performance was assessed after sequential exposure to placebo, low-dose caffeine (2.5 mg/kg), high-dose caffeine (5.0 mg/kg), and high-dose propranolol (0.6 mg/kg). On day 2, performance was assessed after sequential exposure to placebo, low-dose propranolol (0.2 mg/kg), high-dose propranolol (0.6 mg/kg), and high-dose caffeine (5.0 mg/kg). INTERVENTIONS Surgical simulation tasks were repeated 30 minutes after masked ingestion of placebo, caffeine, or propranolol pills during the 2 days. MAIN OUTCOMES AND MEASURES An Eyesi surgical simulator was used to assess surgical performance, which included surgical score (range, 0 [worst] to 700 [best]), task completion time, intraocular trajectory, and tremor rate (range, 0 [worst] to 100 [best]). The nonparametric Friedman test followed by Dunn-Bonferroni post hoc test was applied for multiple comparisons. RESULTS Of 15 vitreoretinal surgeons, 9 (60%) were male, with a mean (SD) age of 29.6 (1.4) years and mean (SD) body mass index (calculated as weight in kilograms divided by height in meters squared) of 23.15 (2.9). Compared with low-dose propranolol, low-dose caffeine was associated with a worse total surgical score (557.0 vs 617.0; difference, -53.0; 95% CI, -99.3 to -6.7; P = .009), a lower antitremor maneuver score (55.0 vs 75.0; difference, -12.0; 95% CI, -21.2 to -2.8; P = .009), longer intraocular trajectory (2298.6 vs 2080.7 mm; difference, 179.3 mm; 95% CI, 1.2-357.3 mm; P = .048), and increased task completion time (14.9 minutes vs 12.7 minutes; difference, 2.3 minutes; 95% CI, 0.8-3.8 minutes; P = .048). Postcaffeine treatment with propranolol was associated with performance improvement; however, surgical performance remained inferior compared with low-dose propranolol alone for total surgical score (570.0 vs 617.0; difference, -51.0; 95% CI, -77.6 to -24.4; P = .01), tremor-specific score (50.0 vs 75.0; difference, -16.0; 95% CI, -31.8 to -0.2; P = .03), and intraocular trajectory (2265.9 mm vs 2080.7 mm; difference, 166.8 mm; 95% CI, 64.1-269.6 mm; P = .03). CONCLUSIONS AND RELEVANCE The findings suggest that performance of novice vitreoretinal surgeons was worse after receiving low-dose caffeine alone but improved after receiving low-dose propranolol alone. Their performance after receiving propranolol alone was better than after the combination of propranolol and caffeine. These results may be helpful for novice vitreoretinal surgeons to improve microsurgical performance.
3.
Thyrotoxicosis: Diagnosis and Management.
Sharma, A, Stan, MN
Mayo Clinic proceedings. 2019;(6):1048-1064
Abstract
Thyrotoxicosis is the clinical manifestation of excess thyroid hormone action at the tissue level due to inappropriately high circulating thyroid hormone concentrations. Hyperthyroidism, a subset of thyrotoxicosis, refers specifically to excess thyroid hormone synthesis and secretion by the thyroid gland. We performed a review of the literature on these topics utilizing published data in PubMed and MEDLINE. In this review, we discuss the more common etiologies of thyrotoxicosis, focusing on the current approach to diagnosis and management, new trends in those directions, and potential upcoming changes in the field.
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Oral propranolol in prevention of severe retinopathy of prematurity: a systematic review and meta-analysis.
Stritzke, A, Kabra, N, Kaur, S, Robertson, HL, Lodha, A
Journal of perinatology : official journal of the California Perinatal Association. 2019;(12):1584-1594
Abstract
OBJECTIVE To systematically assess the efficacy of oral beta blockage treatment in primary (before established) and secondary (in threshold stages) prevention of severe retinopathy of prematurity (ROP) in premature infants born ≤32 weeks gestational age. STUDY DESIGN Following the PRISMA guidelines, published literature was systematically assessed up to April 27, 2018. Trials and observational studies, in which beta blockage was used to prevent severe ROP (defined as stage ≥3, or requiring treatment) were included. Meta-analyses including random effects models were conducted to determine the overall effect of oral beta blockage on prevention of ROP. RESULTS Six studies (five clinical trials and one observational study) including 461 infants met inclusion criteria using propranolol. The pooled relative risk (RR) of severe ROP in the primary and secondary prophylaxis groups were 0.65 (95% CI 0.43-0.98, NNT = 7) and 0.48 (95% CI 0.35-0.65, NNT = 6) in RCTs, respectively. The RR of severe ROP in one observational study was 0.21 (95% CI 0.08-0.55) with a NNT of 3. There were low heterogeneity and publication bias. Side effects occurred in 8.4% of participants on propranolol. CONCLUSIONS Systematic assessment of studies showed that prophylactic oral propranolol appeared to be effective in preventing severe ROP in premature infants ≤32 weeks gestational age. Additional well powered, multinational, randomized control trials reporting on long-term outcomes are needed.