Abstract Background Perioperative stroke, delirium, and cognitive impairment could be related to management and to variations in blood pressure control, cerebral hypoperfusion and raised blood volume. Cerebral autoregulation (CAR) is a mechanism to maintain cerebral perfusion through the control of the vascular tone and hemodynamic reactions in the circulation. Objective The present systematic review addresses the relationship between impaired CAR and perioperative stroke by evaluating the rate of neurological complications after surgery in studies in which perioperative CAR was tested or monitored. Methods We included randomized clinical trials and prospective observational studies. All studies had adjusted the relative risk, hazard ratio or 95% confidence interval (95%CI) values. These estimation effects were tested using random-effects models. Heterogeneity among the selected studies was assessed using the Higgins and Thompson I2 statistics. Results The Web of Science, PubMed and EMBASE electronic databases were searched to retrieve articles. A total of 4,476 studies published between 1983 and 2019 were analyzed, but only 5 qualified for the data extraction and were included in the final analysis. The combined study cohort comprised 941 patients who underwent CAR monitoring during surgical procedures. All studies provided information about perioperative stroke, which equated to 16% (158 of 941) of the overall patient population. Conclusion The present meta-analysis showed evidence of the impact of CAR impairment in the risk of perioperative stroke. On the pooled analysis, blood fluctuations or other brain insults large enough to compromise CAR were associated with the outcome of stroke (odds ratio [OR]: 2.26; 95%CI: 1.54–2.98;p < 0.0001). delirium volume (CAR circulation monitored 95 95%CI 95CI CI (95%CI values randomeffects random models I statistics Science articles 4476 4 476 4,47 198 201 analyzed analysis 94 procedures 16 158 (15 population metaanalysis meta odds OR [OR] 2.26 226 2 26 1.54–2.98p 154298p p 1.54–2.98 1 54 98 0.0001. 00001 0.0001 . 0 0001 0.0001) 9 447 47 4,4 19 20 15 (1 [OR 2.2 22 98p 154298 1.54–2.9 0000 0.000 000 44 4, ( 2. 15429 1.54–2. 0.00 00 1542 1.54–2 0.0 154 1.54– 0. 1.54 1.5 1.

Resumo Antecedentes Acidente vascular cerebral (AVC) perioperatório, delírio e comprometimento cognitivo podem estar relacionados ao manejo e à variações no controle da pressão arterial, à hipoperfusão cerebral, e ao aumento do volume sanguíneo. A autorregulação cerebral (ARC) é um mecanismo para manter a perfusão cerebral por meio do controle do tônus vascular e das reações hemodinâmicas na circulação. Objetivo Este trabalho aborda sistematicamente a determinação da relação entre a falha da ARC e o AVC perioperatório, com uma avaliação da taxa de complicações neurológicas pós-cirúrgicas em estudos em que a ARC perioperatória foi monitorada. Métodos Esta revisão sistemática incluiu ensaios clínicos randomizados e estudos observacionais prospectivos. Todos os estudos ajustaram o risco relativo, a razão de risco ou os valores de intervalo de confiança de 95% (IC95%). Esses efeitos de estimativas foram testados usando modelos de efeitos aleatórios. A heterogeneidade entre os diferentes estudos foi avaliada por meio das estatísticas de Higgins e Thompson I2. Resultados As bases de dados eletrônicas Web of Science, PubMed e Embase foram pesquisadas para selecionar os artigos. Um total de 4.476 estudos publicados entre 1983 e 2019 foram analisados, mas apenas 5 se qualificavam para a extração de dados e foram incluídos na análise final. A coorte combinada do estudo foi composta por 941 pacientes. Todos os estudos forneceram informações sobre AVC perioperatório, o que equivaleu a 16% (158 de 941) da população geral de pacientes. Conclusão Esta meta-análise mostrou evidências do impacto do prejuízo da ARC no risco de AVC perioperatório. Na análise conjunta, as flutuações sanguíneas ou outros insultos cerebrais grandes o suficiente para comprometer a ARC foram associados ao resultado do AVC (razão de probabilidades [RP]: 2,26; IC95%: 1,54–2,98;p < 0,0001). (AVC perioperatório arterial sanguíneo (ARC circulação póscirúrgicas pós cirúrgicas monitorada prospectivos relativo 95 IC95%. IC95 IC IC95% . (IC95%) aleatórios I2 I Science artigos 4476 4 476 4.47 198 201 analisados final 94 pacientes 16 158 (15 metaanálise meta conjunta RP [RP] 2,26 226 2 26 1,54–2,98p 154298p p 1,54–2,98 1 54 98 0,0001. 00001 0,0001 0 0001 0,0001) 9 IC9 (IC95% 447 47 4.4 19 20 15 (1 [RP 2,2 22 98p 154298 1,54–2,9 0000 0,000 000 (IC95 44 4. ( 2, 15429 1,54–2, 0,00 00 (IC9 1542 1,54–2 0,0 (IC 154 1,54– 0, 1,54 1,5 1,

Abstract Introduction Arterial Blood Pressure is a significant indicator of the current health condition of an individual. The correct detection of hypertension is essential, where this health problem is considered as one of the greatest health risks factors that affect the heart and circulatory system. This paper presents the importance of the application of metrological criteria for the diagnosis of hypertension using a sphygmomanometer aneroid. Methods 72 mechanical aneroid sphygmomanometers were calibrated using a standard manometer and the indication error, hysteresis, air leakage and rapid exhaust were determined; readings of these sphygmomanometers were compared to a properly calibrated and adjusted aneroid sphygmomanometer to carry out pressure measurements as those made during the hypertension diagnosis; the uncertainty of measurement associated with the sphygmomanometers calibration, and pressure values was assessed according to the recommendations of the Guide to the Expression of Uncertainty in Measurement, defined by the Joint Committee for Guides in Metrology. Results The results obtained have shown that about 61% of the evaluated aneroid sphygmomanometers did not meet the specifications. The variable that most contributed to the final calibration uncertainty was the hysteresis of the standard manometer, with 53% of contribution, followed by the sphygmomanometer resolution with 27%. Conclusion The periodic verifications are essential to evaluate the performance of these devices. It was shown that uncertainty of measurement influences the final diagnosis of hypertension and the application of metrological criteria can increase the reliability of the final diagnosis.