MARCELO DE LIMA OLIVEIRA
Projetos de Pesquisa
Unidades Organizacionais
LIM/26 - Laboratório de Pesquisa em Cirurgia Experimental, Hospital das Clínicas, Faculdade de Medicina
8 resultados
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- Cerebral hemodynamics with intra-aortic balloon pump: business as usual?(2017) CALDAS, J. R.; PANERAI, R. B.; BOR-SENG-SHU, E.; ALMEIDA, J. P.; FERREIRA, G. S. R.; CAMARA, L.; NOGUEIRA, R. C.; OLIVEIRA, M. L.; JATENE, F. B.; ROBINSON, T. G.; HAJJAR, L. A.Objective: Intra-aortic balloon pump (IABP) is commonly used as mechanical support after cardiac surgery or cardiac shock. Although its benefits for cardiac function have been well documented, its effects on cerebral circulation are still controversial. We hypothesized that transfer function analysis (TFA) and continuous estimates of dynamic cerebral autoregulation (CA) provide consistent results in the assessment of cerebral autoregulation in patients with IABP. Approach: Continuous recordings of blood pressure (BP, intra-arterial line), end-tidal CO2, heart rate and cerebral blood flow velocity (CBFV, transcranial Doppler) were obtained (i) 5 min with IABP ratio 1: 3, (ii) 5 min, starting 1 min with the IABP-ON, and continuing for another 4 min without pump assistance (IABP-OFF). Autoregulation index (ARI) was estimated from the CBFV response to a step change in BP derived by TFA and as a function of time using an autoregressive moving-average model during removal of the device (ARI(t)). Critical closing pressure and resistance area-product were also obtained. Main results: ARI with IABP-ON (4.3 +/- 1.2) were not different from corresponding values at IABP-OFF (4.7 +/- 1.4, p = 0.42). Removal of the balloon had no effect on ARIt, CBFV, BP, cerebral critical closing pressure or resistance area-product. Significance: IABP does not disturb cerebral hemodynamics. TFA and continuous estimates of dynamic CA can be used to assess cerebral hemodynamics in patients with IABP. These findings have important implications for the design of studies of critically ill patients requiring the use of different invasive support devices.
- TCD assessment in fulminant hepatic failure: Improvements in cerebral autoregulation after liver transplantation(2024) PASCHOAL-JR, Fernando M.; NOGUEIRA, Ricardo C.; RONCONI, Karla de Almeida Lins; OLIVEIRA, Marcelo de Lima; ALMEIDA, Kelson James; ROCHA, Ivana Schmidtbauer; PASCHOAL, Eric Homero Albuquerque; PASCHOAL, Joelma Karin Sagica Fernandes; D'ALBUQUERQUE, Luiz Augusto Carneiro; TEIXEIRA, Manoel Jacobsen; PANERAI, Ronney B.; BOR-SENG-SHU, EdsonIntroduction and Objectives: Acute liver failure, also known as fulminant hepatic failure (FHF), includes a spectrum of clinical entities characterized by acute liver injury, severe hepatocellular dysfunction and hepatic encephalopathy. The objective of this study was to assess cerebral autoregulation (CA) in 25 patients (19 female) with FHF and to follow up seventeen of these patients before and after liver transplantation.Patients and Methods: The mean age was 33.8 years (range 14-56, SD 13.1 years). Cerebral hemodynamics was assessed by transcranial Doppler (TCD) bilateral recordings of cerebral blood velocity (CBv) in the middle cerebral arteries (MCA).Results: CA was assessed based on the static CA index (SCAI), reflecting the effects of a 20-30 mmHg increase in mean arterial blood pressure on CBv induced with norepinephrine infusion. SCAI was estimated at four time points: pretransplant and on the 1st, 2nd and 3rd posttransplant days showing a significant difference between pre-and posttransplant SCAI (p = 0.005). SCAI peaked on the third posttransplant day (p = 0.006). Categorical analysis of SCAI showed that for most patients, CA was reestablished on the second day post-transplant (SCAI > 0.6).Conclusions: These results suggest that CA impairment pretransplant and on the 1st day posttransplant was re-established at 48-72 h after transplantation. These findings can help to improve the management of this patient group during these specific phases, thereby avoiding neurological complications, such as brain swelling and intracranial hypertension.(c) 2023 Fundacion Clinica Medica Sur, A.C.
- Dynamic cerebral autoregulation: A marker of post-operative delirium?(2019) CALDAS, Juliana R.; PANERAI, Ronney B.; BOR-SENG-SHU, Edson; FERREIRA, Graziela S. R.; CAMARA, Ligia; PASSOS, R. H.; DE-LIMA-OLIVEIRA, Marcelo; GALAS, Filomena R. B. G.; ALMEIDA, Juliano P.; NOGUEIRA, Ricardo C.; MIAN, Natalia; GAIOTTO, Fabio A.; ROBINSON, Thompson G.; HAJJAR, Ludhmila A.Objective: We investigated the potential association of cerebral autoregulation (CA) with postoperative delirium (PD), a common complication of cardiac surgery with cardiopulmonary bypass (CPB). Methods: In patients undergoing coronary artery bypass graft (CABG) surgery with CPB, cerebral blood flow velocity (CBFV) and blood pressure (BP) were continuously recorded during 5-min preoperatively (T1), after 24 h (T2), and 7 days after procedure (T3). Prospective multivariate logistic regression analysis was performed to determine the independent risk factors of PD. Autoregulation index (ARI) was calculated from the CBFV response to a step change in BP derived by transfer function analysis. Results: In 67 patients, mean age 64.3 +/- 9.5 years, CA was depressed at T2 as shown by values of ARI (3.9 +/- 1.7), compared to T1 (5.6 +/- 1.7) and T3 (5.5 +/- 1.8) (p < 0.001). Impaired CA was found in 37 (55%) patients at T2 and in 7 patients (20%) at T3. Lower ARI at T1 and T2 were predictors of PD (p = 0.003). Conclusion: Dynamic CA was impaired after CABG surgery with CPB and was a significant independent risk factor of PD. Significance: Assessment of CA before and after surgery could have considerable potential for early identification of patients at risk of PD, thus reducing poor outcomes and length of stay.
- Integrative assessment of cerebral blood regulation in COPD patients(2024) CORRE, Daniel I.; DE-LIMA-OLIVEIRA, Marcelo; NOGUEIRA, Ricardo C.; CARVALHO-PINTO, Regina M.; BOR-SENG-SHU, Edson; PANERAI, Ronney B.; CARVALHO, Celso R. F.; SALINET, Angela S. M.Cerebrovascular responses were compared between COPD and non-COPD participants. The association between COPD severity and cognitive function was also investigated. Cerebral blood velocity in the middle cerebral artery, blood pressure, and end-tidal CO2 were recorded at rest, followed by a brain activation paradigm, and an inhaled gas mixture (5% CO2) to assess cerebral autoregulation (CA), neurovascular coupling (NVC) and cerebrovascular reactivity to carbon dioxide (CVRCO2), respectively. Pulmonary function, blood gas analysis (COPD) and cognitive function (MoCA test) were also performed. No difference in baseline (systemic and cerebral parameters) and CA was found between 20 severe COPD and 21 non-COPD. Reduced NVC and CVRCO2 test were found in the COPD group. Lower pulmonary function was positively correlated with CA, NVC and CVRCO2 in COPD patients. Cognitive impairment (MoCA<26) was associated with lower NVC responses (COPD and non-COPD) and lower pulmonary function (COPD). Both mechanisms, CVRCO2 and NVC, were lower in COPD patients. Moreover, disease severity and cognitive impaired were associated with worse cerebrovascular regulation.
- Intra-aortic balloon pump does not influence cerebral hemodynamics and neurological outcomes in high-risk cardiac patients undergoing cardiac surgery: an analysis of the IABCS trial(2019) CALDAS, Juliana R.; PANERAI, Ronney B.; BOR-SENG-SHU, Edson; FERREIRA, Graziela S. R.; CAMARA, Ligia; PASSOS, Rogerio H.; SALINET, Angela M.; AZEVEDO, Daniel S.; DE-LIMA-OLIVEIRA, Marcelo; GALAS, Filomena R. B. G.; FUKUSHIMA, Julia T.; NOGUEIRA, Ricardo; TACCONE, Fabio S.; LANDONI, Giovanni; ALMEIDA, Juliano P.; ROBINSON, Thompson G.; HAJJAR, Ludhmila A.Background The intra-aortic balloon pump (IABP) is often used in high-risk patients undergoing cardiac surgery to improve coronary perfusion and decrease afterload. The effects of the IABP on cerebral hemodynamics are unknown. We therefore assessed the effect of the IABP on cerebral hemodynamics and on neurological complications in patients undergoing cardiac surgery who were randomized to receive or not receive preoperative IABP in the 'Intra-aortic Balloon Counterpulsation in Patients Undergoing Cardiac Surgery' (IABCS) trial. Methods This is a prospectively planned analysis of the previously published IABCS trial. Patients undergoing elective coronary artery bypass surgery with ventricular ejection fraction <= 40% or EuroSCORE >= 6 received preoperative IABP (n = 90) or no IABP (n = 91). Cerebral blood flow velocity (CBFV) of the middle cerebral artery through transcranial Doppler and blood pressure through Finometer or intra-arterial line were recorded preoperatively (T1) and 24 h (T2) and 7 days after surgery (T3) in patients with preoperative IABP (n = 34) and without IABP (n = 33). Cerebral autoregulation was assessed by the autoregulation index that was estimated from the CBFV response to a step change in blood pressure derived by transfer function analysis. Delirium, stroke and cognitive decline 6 months after surgery were recorded. Results There were no differences between the IABP and control patients in the autoregulation index (T1: 5.5 +/- 1.9 vs. 5.7 +/- 1.7; T2: 4.0 +/- 1.9 vs. 4.1 +/- 1.6; T3: 5.7 +/- 2.0 vs. 5.7 +/- 1.6, p = 0.97) or CBFV (T1: 57.3 +/- 19.4 vs. 59.3 +/- 11.8; T2: 74.0 +/- 21.6 vs. 74.7 +/- 17.5; T3: 71.1 +/- 21.3 vs. 68.1 +/- 15.1 cm/s; p = 0.952) at all time points. Groups were not different regarding postoperative rates of delirium (26.5% vs. 24.2%, p = 0.83), stroke (3.0% vs. 2.9%, p = 1.00) or cognitive decline through analysis of the Mini-Mental State Examination (16.7% vs. 40.7%; p = 0.07) and Montreal Cognitive Assessment (79.16% vs. 81.5%; p = 1.00). Conclusions The preoperative use of the IABP in high-risk patients undergoing cardiac surgery did not affect cerebral hemodynamics and was not associated with a higher incidence of neurological complications. Trial registration (NCT02143544).
- Cerebral blood flow autoregulation in ischemic heart failure(2017) CALDAS, J. R.; PANERAI, R. B.; HAUNTON, V. J.; ALMEIDA, J. P.; FERREIRA, G. S. R.; CAMARA, L.; NOGUEIRA, R. C.; BOR-SENG-SHU, E.; OLIVEIRA, M. L.; GROEHS, R. R. V.; FERREIRA-SANTOS, L.; TEIXEIRA, M. J.; GALAS, F. R. B. G.; ROBINSON, T. G.; JATENE, F. B.; HAJJAR, L. A.Patients with ischemic heart failure (iHF) have a high risk of neurological complications such as cognitive impairment and stroke. We hypothesized that iHF patients have a higher incidence of impaired dynamic cerebral autoregulation (dCA). Adult patients with iHF and healthy volunteers were included. Cerebral blood flow velocity (CBFV, transcranial Doppler, middle cerebral artery), end-tidal CO2 (capnography), and arterial blood pressure (Finometer) were continuously recorded supine for 5 min at rest. Autoregulation index (ARI) was estimated from the CBFV step response derived by transfer function analysis using standard template curves. Fifty-two iHF patients and 54 age-, gender-, and BP-matched healthy volunteers were studied. Echocardiogram ejection fraction was 40 (20-45) % in iHF group. iHF patients compared with control subjects had reduced end-tidal CO2 (34.1 +/- 3.7 vs. 38.3 +/- 4.0 mmHg, P < 0.001) and lower ARI values (5.1 +/- 1.6 vs. 5.9 +/- 1.0, P = 0.012). ARI <4, suggestive of impaired CA, was more common in iHF patients (28.8 vs. 7.4%, P = 0.004). These results confirm that iHF patients are more likely to have impaired dCA compared with age-matched controls. The relationship between impaired dCA and neurological complications in iHF patients deserves further investigation.
- Dynamic cerebral autoregulation is impaired during submaximal isometric handgrip in patients with heart failure(2018) CALDAS, J. R.; PANERAI, R. B.; SALHIET, A. M.; SENG-SHU, E.; FERREIRA, G. S. R.; CAMARA, L.; PASSOS, R. H.; GALAS, F. R. B. G.; ALMEIDA, J. P.; NOGUEIRA, R. C.; OLIVEIRA, M. de Lima; ROBINSON, T. G.; HAJJAR, L. A.The incidence of neurological complications, including stroke and cognitive dysfunction, is elevated in patients with heart failure (HF) with reduced ejection fraction. We hypothesized that the cerebrovascular response to isometric handgrip (iHG) is altered in patients with HF. Adults with HF and healthy volunteers were included. Cerebral blood velocity (CBV; transcranial Doppler, middle cerebral artery) and arterial blood pressure (BP; Finometer) were continuously recorded supine for 6 min, corresponding to 1 min of baseline and 3 min of iHG exercise, at 30% maximum voluntary contraction, followed by 2 min of recovery. The resistance-area product was calculated from the instantaneous BP-CBV relationship. Dynamic cerebral autoregulation (dCA) was assessed with the time-varying autoregulation index estimated from the CBV step response derived by an autoregressive moving-average time-domain model. Forty patients with HF and 23 BP-matched healthy volunteers were studied. Median left ventricular ejection fraction was 38.5% (inter-quartile range: 0.075%) in the HF group. Compared with control subjects. patients with HF exhibited lower time-varying autoregulation index during iHG, indicating impaired dCA (P < 0.025). During iHG, there were steep rises in CBV. BP, and heart rate in control subjects but with different temporal patterns in HF, which, together with the temporal evolution of resistance-area product, confirmed the disturbance in dCA in HF. Patients with HF were more likely to have impaired dCA during iHG compared with age-matched control subjects. Our results also suggest an impairment of myogenic, neurogenic. and metabolic control mechanisms in HF. The relationship between impaired dCA and neurological complications in patients with HF during exercise deserves further investigation. NEW & NOTEWORTHY Our findings provide the first direct evidence that cerebral blood flow regulatory mechanisms can be affected in patients with heart failure during isometric handgrip exercise. As a consequence, eventual blood pressure modulations are buffered less efficiently and metabolic demands may not be met during common daily activities. These deficits in cerebral autoregulation are compounded by limitations of the systemic response to isometric exercise, suggesting that patients with heart failure may be at greater risk for cerebral events during exercise.
- Impaired cerebral autoregulation and neurovascular coupling in middle cerebral artery stroke: Influence of severity?(2019) SALINET, Angela S. M.; SILVA, Nathalia C. C.; CALDAS, Juliana; AZEVEDO, Daniel S. de; DE-LIMA-OLIVEIRA, Marcelo; NOGUEIRA, Ricardo C.; CONFORTO, Adriana B.; TEXEIRA, Manoel J.; ROBINSON, Thompson G.; PANERAI, Ronney B.; BOR-SENG-SHU, EdsonWe aimed to assess cerebral autoregulation (CA) and neurovascular coupling (NVC) in stroke patients of differing severity comparing responses to healthy controls and explore the association between CA and NVC with functional outcome. Patients admitted with middle cerebral artery (MCA) stroke and healthy controls were recruited. Stroke severity was defined by the National Institutes of Health Stroke Scale (NIHSS) scores: <= 4 mild, 5-15 moderate and >= 16 severe. Transcranial Doppler ultrasound and Finometer recorded MCA cerebral blood flow velocity (CBFv) and blood pressure, respectively, over 5 min baseline and 1 min passive movement of the elbow to calculate the autoregulation index (ARI) and CBFv amplitude responses to movement. All participants were followed up for three months. A total of 87 participants enrolled in the study, including 15 mild, 27 moderate and 13 severe stroke patients, and 32 control subjects. ARI was lower in the affected hemisphere (AH) of moderate and severe stroke groups. Decreased NVC was seen bilaterally in all stroke groups. CA and NVC correlated with stroke severity and functional outcome. CBFv regulation is significantly impaired in acute stroke, and further compromised with increasing stroke severity. Preserved CA and NVC in the acute period were associated with improved three-month functional outcome.