MARCELO DE LIMA OLIVEIRA
Projetos de Pesquisa
Unidades Organizacionais
LIM/26 - Laboratório de Pesquisa em Cirurgia Experimental, Hospital das Clínicas, Faculdade de Medicina
6 resultados
Resultados de Busca
Agora exibindo 1 - 6 de 6
- Experimental rnodel of intracranial hypertension with continuous multiparametric monitoring in swine(2013) ANDRADE, Almir Ferreira de; SOARES, Matheus Schmidt; PATRIOTA, Gustavo Cartaxo; BELON, Alessandro Rodrigo; PAIVA, Wellingson Silva; BOR-SENG-SHU, Edson; OLIVEIRA, Marcelo de Lima; NASCIMENTO, Clarissa Nobrega; NOLETO, Gustavo Sousa; ALVES JUNIOR, Aderaldo Costa; FIGUEIREDO, Eberval Gadelha; OTOCH, Jose Pinhata; TEIXEIRA, Manoel JacobsenObjective: Intracranial hypertension (IN) develops in approximately 50% of all patients with severe traumatic brain injury (TBI). Therefore, it is very important to identify a suitable animal model to study and understand the pathophysiology of refractory IH to develop effective treatments. Methods: We describe a new experimental porcine model designed to simulate expansive brain hematoma causing IH. Under anesthesia, was simulated with a balloon insufflation. The IH variables were measured with intracranial pressure (ICP) parenchymal monitoring, epidural, cerebral oximetry, and transcranial Doppler (TCD). Results: None of the animals died during the experiment. The ICP epidural showed a slower rise compared with parenchymal ICP. We found a correlation between ICP and cerebral oximetry. Conclusion: The model described here seems useful to understand some of the pathophysiological characteristics of acute IH.
- 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.
- The influence of intracranial hypertension on static cerebral autoregulation(2020) DE-LIMA-OLIVEIRA, Marcelo; FERREIRA, Almir Andrade; BELON, Alessandro Rodrigo; SALINET, Angela Macedo; NOGUEIRA, Ricardo Carvalho; PING, Brasil Chian; PAIVA, Wellingson Silva; TEIXEIRA, Manoel Jacobsen; BOR-SENG-SHU, EdsonObjectives To analyze the influences of mild and severe intracranial hypertension on cerebral autoregulation (CA). Patients and Methods Duroc piglets were monitored with an intracranial pressure (ICP) catheter. Intracranial hypertension was induced via infusion of 4 or 7 ml of saline solution by a bladder catheter that was inserted into the parietal lobe. The static cerebral autoregulation (sCA) index was evaluated via cerebral blood flow velocities (CBFv). Piglets with ICPs <= 25 and > 25 mmHg were considered as group 1 and 2, respectively. Continuous variables were evaluated using the Kolmogorov-Smirnov goodness-of-fit test. The main parameters were collected before and after ICH induction and compared using two-factor mixed-design ANOVAs with the factor of experimental group (mild and severe ICH). Results In group 1 (ICP <= 25 mmHg), there were significant differences in sCA (p= .01) and ICP (p= .0002) between the basal and balloon inflation conditions. In group 2 (ICP > 25 mmHg), there were significant differences in CBFv (p= .0072), the sCA index (p= .0001) and ICP (p= .00001) between the basal and balloon inflation conditions. Conclusion We conclude that ICH may have a direct effect on mild and severe sCA.
- Evaluation of Head Computed Tomography Assessment of Brain Swelling after Acute Traumatic Brain Injury: A Pilot study(2019) AMORIM, Robson Luis; MORAIS, Barbara Albuquerque; PEREIRA, Francisco Otavio Camargo; OLIVEIRA, Matheus Fernandes; ANDRADE, Almir Ferreira; BOR-SENG-SHU, Edson; OLIVEIRA, Marcelo Lima; TEIXEIRA, Manoel Jacobsen; PAIVA, Wellingson SilvaObjective To evaluate the interobserver reliability of a new scale created for quantitatively assessing brain swelling in traumatic brain injury (TBI) patients using the computed tomography (CT) findings in three levels. Methods Computed tomography scans of severe head injury patients were randomly selected from a tertiary hospital image database and evaluated by independent groups of neurosurgeons, neurosurgery residents, radiologists, and intensivists from the same hospital. Each specialist assessed the tomographic findings, applying zero to six points in a new scale. The Kappa coefficient was calculated to assess interobserver agreement. Results The highest reliability coefficient was obtained by the neurosurgeons group (0.791; 95% confidence interval [CI]: 0.975-0.607; p < 0.001), followed by the neurosurgery residents group (0.402; 95%CI: 0.569-0.236; p < 0.001) and by the radiologists group (0.301; 95%CI: 0.488-0.113; p < 0.002). The lowest coefficient was found among the intensivists (0.248; 95%CI: 0.415-0.081; p = 0.004). Conclusion The proposed scale showed good reliability among neurosurgeons, and moderate overall reliability. This tomographic classification might be useful to better assist severe TBI victims, allowing to identify the worsening or amelioration of brain swelling, which should be further investigated. The scale seems to be feasible, even in low income countries, where the cost of intracranial pressure (ICP) monitoring is higher than that of CTs.
conferenceObject INTRACRANIAL HYPERTENSION MODEL IN PIGS: ASSESSMENT WITH TRANSCRANIAL DOPPLER AND INTRACRANIAL PRESSURE MONITORING(2014) ANDRADE, Almir Ferreira de; MATHEUS, S.; PATRIOTA, Gustavo C.; BELON, Alessandro; PAIVA, Wellingson S.; JENG, Brasil P.; BOR-SENG-SHU, Edson; OLIVEIRA, Marcelo; NASCIMENTO, Clarissa; AMORIM, Robson; FIGUEIREDO, Eberval G.; OTOCH, Jose P.; TEIXEIRA, Manoel J.