Célia Regina Lopes

Effects of noninvasive ventilation on heart rate variability after coronary bypass grafting: comparison between ventilators

Dear Editor, Postoperative complications of coronary artery bypass grafting (CABG) are related to the amendment of pulmonary and autonomic function. Noninvasive ventilation (NIV) is indicated to reduce the risk of such complications and promotes beneficial effects on lung function, as in autonomic modulation [1]. NIV can be performed with a conventional ventilator (CV) or a specific ventilator (SV), designed specifically for application of NIV. The difference between the equipment is basically the system that is able to compensate the leakage. There are no studies demonstrating induced responses on autonomic modulation and hemodynamic changes by NIV in postoperative CABG patients using different equipment. Therefore, ten postoperative CABG patients underwent the NIV procedure with two different ventilators, CV (DX 3012 , Dixtal) and SV (BiPAP Vision , Respironics), for 30 min each in this sequential, crossover study. Block randomization was used to determine the first technique to be applied; thereafter, the other procedure was performed. The positive expiratory pressure was set at 8 cmH2O, the fraction of inspired oxygen was adjusted to maintain oxygen saturation (SpO2) above 90 %, and the support pressure or inspiratory final pressure was adjusted to maintain a tidal volume (TV) of 8 mL/kg. The heart rate variability (HRV), systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) were evaluated during 15 min before starting the procedures, 30 min during application of NIV with each ventilator, and 15 min after the procedures. Data collection started 4 h after extubation, and the patient was not under anesthetic effects. The HRV was analyzed using the time domain and frequency domain. The patients showed a mean and standard deviation of extracorporeal circulation and mechanical ventilation time of 65 min (±10 min) and 12 h (±3 h), respectively. On the performance of NIV with the SV there was an increase in the high frequency (HF) index and DBP (Table 1). However, in NIV with the CV there was an increase in HR and SBP. There was no difference between the HRV indexes recorded before and after NIV, and also no significant correlation between

Análise dos efeitos do ultrassom terapêutico e da eletrolipoforese nas alterações decorrentes do fibroedema geloide

Abstract Introduction : Body disharmony syndrome (CDS) includes the presence of fibroedema geloid (EGF), adipos-ity, increased total body fat and muscle weakness, often associated with these disorders and aesthetic pose a threat to the emotional integrity of the individual, where a variety therapies have been proposed for treatment. Objectives : To evaluate the effects of therapeutic ultrasound (TUS) and eletrolipoforese in the treatment of changes caused by fibroedema geloid. Materials and methods : We studied 22 volunteers, aged 17-35 years, presence of EGF and grades 1 or 2 in the buttocks, sedentary and contraceptive use. The variables were previ-ously perimetry, sensitivity, pain, personal satisfaction, calipers, photographic assessment, bipolar electrical bioimpedance. Ten sessions were held with TU in 11 of the volunteers and the other 11 volunteers received treatment for eletrolipoforese. All techniques were applied bilaterally in the gluteal region, three times a week, and at the end of the treatment variables were evaluated. Statistical analysis was applied the Student t-test to verify the significance between the results obtained in each treatment and between treatments. Level of significance was set at p < 0.05.

Efeitos agudos da ventilação mecânica com hiperoxia na morfometria do diafragma de ratos

BACKGROUND: Prolonged mechanical ventilatory support (MVS) combined with high oxygen concentrations has a negative impact on diaphragm function. However, the acute effects of MVS with hyperoxia have not been elucidated. Objective: To analyze the acute effects of mechanical ventilation with hyperoxia on the morphometry of the rat diaphragm. METHODS: An experimental, prospective study was conducted with Wistar rats (weight: 400±20 g), which were randomly allocated to two groups. The control group (n=4) was anesthetized, tracheostomized and kept spontaneously breathing room air for 90 minutes. The experimental group (n=5) was also anesthetized, curarized, tracheostomized and kept in controlled mechanical ventilation for the same amount of time. Both groups were submitted to median thoracotomy for sample collection of costal fibers from the diaphragm muscle, which were sectioned every 5 μm and stained with hematoxylin and eosin for the morphometric study. Independent Students t tests were employed to investigate differences between groups, with a significance level of p<0.05. RESULTS: There were no signs of acute muscle lesions, however the blood capillaries became dilated in the experimental group. The mean morphometric data related to the maximum cross-sectional diameter of the diaphragm costal fibers were 61.78 ±17.79 µm and 70.75±9.93 µm (p=0.045) for the control and experimental groups, respectively. CONCLUSIONS: Short-term mechanical ventilation with hyperoxia led to significant microvascular and muscle changes, which may reflect the onset of an inflammatory process.

Doppler echocardiographic evaluation of hemodynamic effects of applying bilevel positive airway pressure

Introduction: Application of noninvasive positive airway pressure triggers significant cardiopulmonary interactions. Objective: This study aimed to identify the hemodynamic effects arising from the application of bilevel pressure to the airways evaluated by echocardiography. Methods: Randomized, double-blind, controlled study was conducted with 19 healthy participants. Random sequence of three expiratory positive airway pressures (EPAPs) was applied for 5 minutes each. The inspiratory pressure remained constant at 5 cmH2O above the established EPAP. Hemodynamic variables, determined using Doppler echocardiography, a non-invasive ventilator, and a heart monitor were recorded. Results: Comparing baseline data with that collected under various EPAPs of 5, 10, and 15 cmH2O showed reduced aortic velocity time integral (p Conclusion: The cardiopulmonary and interventricular repercussions by echocardiography, were expressed by reducing the left ventricular preload and increasing the biventricular preload, stroke volume, and cardiac output, ensuring increased tidal volume and blood oxygenation.