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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- Evaluation of cerebral hemodynamics by transcranial Doppler ultrasonography and its correlation with intracranial pressure in an animal model of intracranial hypertension(2022) SOARES, Matheus Schmidt; ANDRADE, Almir Ferreira de; BRASIL, Sergio; DE-LIMA-OLIVEIRA, Marcelo; BELON, Alessandro Rodrigo; BOR-SENG-SHU, Edson; NOGUEIRA, Ricardo de Carvalho; GODOY, Daniel Agustin; PAIVA, Wellingson SilvaBackground: Transcranial Doppler has been tested in the evaluation of cerebral hemodynamics as a non-invasive assessment of intracranial pressure (ICP), but there is controversy in the literature about its actual benefit and usefulness in this situation. Objective: To investigate cerebral blood flow assessed by Doppler technique and correlate with the variations of the ICP in the acute phase of intracranial hypertension in an animal model. Methods:An experimental animal model of intracranial hypertension was used. The experiment consisted of two groups of animals in which intracranial balloons were implanted and inflated with 4 mL (A) and 7 mL (B) for controlled simulation of different volumes of hematoma. The values of ICP and Doppler parameters (systolic [FVs], diastolic [FVd], and mean [FVm] cerebral blood flow velocities and pulsatility index [PI]) were collected during the entire procedure (before and during hematoma simulations and venous hypertonic saline infusion intervention). Comparisons between Doppler parameters and ICP monitoring were performed. Results: Twenty pigs were studied, 10 in group A and 10 in group B. A significant correlation between PI and ICP was obtained, especially shortly after abrupt elevation of ICP. There was no correlation between ICP and FVs, FVd or FVm separately. There was also no significant change in ICP after intravenous infusion of hypertonic saline solution. Conclusions:These results demonstrate the potential of PI as a parameter for the evaluation of patients with suspected ICP elevation.
- Estimation of intracranial pressure by ultrasound of the optic nerve sheath in an animal model of intracranial hypertension(2021) JENG, Brasil Chian Ping; ANDRADE, Almir Ferreira de; BRASIL, Sergio; BOR-SENG-SHU, Edson; BELON, Alessandro Rodrigo; ROBERTIS, Maira; DE-LIMA-OLIVEIRA, Marcelo; RUBIANO, Andres Mariano; GODOY, Daniel Agustin; TEIXEIRA, Manoel Jacobsen; PAIVA, Wellingson SilvaBackground: Ultrasound of the optic nerve sheath diameter (ONSD) has been used as a non-invasive and cost-effective bedside alternative to invasive intracranial pressure (ICP) monitoring. However, ONSD time-lapse behavior in intracranial hypertension (ICH) and its relief by means of either saline infusion or surgery are still unknown. The objective of this study was to correlate intracranial pressure (ICP) and ultrasonography of the optic nerve sheath (ONS) in an experimental animal model of ICH and deter-mine the interval needed for ONSD to return to baseline levels. Methods: An experimental study was conducted on 30 pigs. ONSD was evaluated by ultrasound at differ-ent ICPs generated by intracranial balloon inflation, saline infusion, and balloon deflation, and measured using an intraventricular catheter. Results: All variables obtained by ONS ultrasonography such as left, right, and average ONSD (AON) were statistically significant to estimate the ICP value. ONSD changed immediately after balloon inflation and returned to baseline after an average delay of 30 min after balloon deflation (p = 0.016). No statistical sig-nificance was observed in the ICP and ONSD values with hypertonic saline infusion. In this swine model, ICP and ONSD showed linear correlation and ICP could be estimated using the formula:-80.5 + 238.2 x AON. Conclusion: In the present study, ultrasound to measure ONSD showed a linear correlation with ICP, although a short delay in returning to baseline levels was observed in the case of sudden ICH relief.
- Assessing ultrasonographic optic nerve sheath diameter in animal model with anesthesia regimens(2022) AZEVEDO, Maira de Robertis; DE-LIMA-OLIVEIRA, Marcelo; BELON, Alessandro Rodrigo; BRASIL, Sergio; TEIXEIRA, Manoel Jacobsen; PAIVA, Wellingson Silva; BOR-SENG-SHU, EdsonPurpose: To determine the normal optical nerve sheath (ONS) diameter ultrasonography (ONSUS) and evaluate the possible effects of drugs on ONS diameter during anesthetic induction in healthy pigs. Methods: Healthy piglets were divided into three groups: a control group, that received xylazine and ketamine (X/K); other that received xylazine, ketamine and propofol (X/K/P); and a third group that received xylazine, ketamine, and thiopental (X/K/T). The sheath diameter was assessed by ultrasonography calculating the average of three measurements of each eye from the left and right sides. Results: 118 animals were anesthetized (49 X/K 33 X/K/P and 39 X/K/T). Mean ONS sizes on both sides in each group were 0.394 +/- 0.048 (X/K), 0.407 +/- 0.029 (X/K/P) and 0.378 +/- 0.042 cm (X/K/T) (medians of 0.400, 0.405 and 0.389, respectively). The ONS diameter varied from 0.287-0.512 cm (mean of 0.302 +/- 0.039 cm). For group X/K, the mean diameter was 0.394 +/- 0.048 cm. Significant differences in ONS sizes between the groups P and T (X/K/P > X/K/T, p = 0.003) were found. No statistically significant differences were detected when other groups were compared (X/K = X/K/P, p = 0.302; X/K = X/K/T, p = 0.294). Conclusion: Sedation with thiopental lead to significative ONS diameter reduction in comparison with propofol. ONSUS may be useful to evaluate responses to thiopental administration.
- Cerebral Hemodynamics and Intracranial Compliance Impairment in Critically Ill COVID-19 Patients: A Pilot Study(2021) BRASIL, Sergio; TACCONE, Fabio Silvio; WAYHS, Samia Yasin; TOMAZINI, Bruno Martins; ANNONI, Filippo; FONSECA, Sergio; BASSI, Estevao; LUCENA, Bruno; NOGUEIRA, Ricardo De Carvalho; DE-LIMA-OLIVEIRA, Marcelo; BOR-SENG-SHU, Edson; PAIVA, Wellingson; TURGEON, Alexis Fournier; TEIXEIRA, Manoel Jacobsen; MALBOUISSON, Luiz Marcelo SaIntroduction: One of the possible mechanisms by which the new coronavirus (SARS-Cov2) could induce brain damage is the impairment of cerebrovascular hemodynamics (CVH) and intracranial compliance (ICC) due to the elevation of intracranial pressure (ICP). The main objective of this study was to assess the presence of CVH and ICC alterations in patients with COVID-19 and evaluate their association with short-term clinical outcomes. Methods: Fifty consecutive critically ill COVID-19 patients were studied with transcranial Doppler (TCD) and non-invasive monitoring of ICC. Subjects were included upon ICU admission; CVH was evaluated using mean flow velocities in the middle cerebral arteries (mCBFV), pulsatility index (PI), and estimated cerebral perfusion pressure (eCPP), while ICC was assessed by using the P2/P1 ratio of the non-invasive ICP curve. A CVH/ICC score was computed using all these variables. The primary composite outcome was unsuccessful in weaning from respiratory support or death on day 7 (defined as UO). Results: At the first assessment (n = 50), only the P2/P1 ratio (median 1.20 [IQRs 1.00-1.28] vs. 1.00 [0.88-1.16]; p = 0.03) and eICP (14 [11-25] vs. 11 [7-15] mmHg; p = 0.01) were significantly higher among patients with an unfavorable outcome (UO) than others. Patients with UO had a significantly higher CVH/ICC score (9 [8-12] vs. 6 [5-7]; p < 0.001) than those with a favorable outcome; the area under the receiver operating curve (AUROC) for CVH/ICC score to predict UO was 0.86 (95% CIs 0.75-0.97); a score > 8.5 had 63 (46-77)% sensitivity and 87 (62-97)% specificity to predict UO. For those patients undergoing a second assessment (n = 29), after a median of 11 (5-31) days, all measured variables were similar between the two time-points. No differences in the measured variables between ICU non-survivors (n = 30) and survivors were observed. Conclusions: ICC impairment and CVH disturbances are often present in COVID-19 severe illness and could accurately predict an early poor outcome.
conferenceObject Assessment of transcranial sonography in traumatic brain injured patients: comparison with cerebral computed tomography(2017) BRASIL, S.; DE-LIMA-OLIVEIRA, M.; OLIVEIRA, R.; PAIVA, W.; BOR-SENG-SHU, E.; TEIXEIRA, M. Jacobsen; MALBOUISSON, M.; BOSSE, E.; EVANGELISTA, M.conferenceObject TRANSCRANIAL DOPPLER PULSATILITY INDEX ACCURACY ON THE INDICATION OF IMPAIRED CEREBRAL COMPLIANCE(2017) BRASIL, S.; DE-LIMA-OLIVEIRA, M.; NOGUEIRA, R.; PAIVA, W.; BOR-SENG-SHU, E.; TEIXEIRA, M. Jacobsen- Determination of Brain Death(2021) BRASIL, Sergio; NOGUEIRA, Ricardo de Carvalho; DE-LIMA-OLIVEIRA, Marcelo
conferenceObject VARIATION OF OPTICAL NERVE SHEATH DIAMETER DURING ANESTHESIA IN EXPERIMENTAL MODEL WITHOUT INTRACRANIAL HYPERTENSION(2017) BRASIL, S.; DE-LIMA-OLIVEIRA, M.; PAIVA, W.; BOSSE, E.; BOR-SENG-SHU, E.; EVANGELISTA, M.; TEIXEIRA, M. Jacobsen; BELON, A.; AZEVEDO, M.