Alfredo José Rodrigues

Pre-and postoperative care in cardiothoracic surgery: a physiotherapeutic approach

It is well known that anesthesia and certain surgeries predispose patients to changes in respiratory function, pulmonary volumes, and gas exchange. Cardiac surgery, which is considered a major surgery, may trigger respiratory complications in the postoperative period. These complications have various causes, such as heart and lung functions in the pre-operative, the use of cardiopulmonary bypass (CPB), and the level of sedation. In these extensive thoracic procedures, respiratory dysfunction may be significant, persisting in the postoperative period. Physiotherapy is offered to patients in the ICU as part of a multidisciplinary treatment plan. It is a time-consuming treatment, and is possible at various times during the patients stay in the ICU. However, it is particularly valuable in postoperative recovery in order to avoid respiratory and motor complications. Thus, a literature review was performed, aiming to arrange current and relevant information on available resources for respiratory monitoring, as well as its importance in evaluating and treating lung function impairment, as this complication is a frequent cause of death in surgical patients.

Diabetes and Vascular Disease: Basic Concepts of Nitric Oxide Physiology, Endothelial Dysfunction, Oxidative Stress and Therapeutic Possibilities

The vascular manifestations associated with diabetes mellitus (DM) result from the dysfunction of several vascular physiology components mainly involving the endothelium, vascular smooth muscle and platelets. It is also known that hyperglycemia-induced oxidative stress plays a role in the development of this dysfunction. This review considers the basic physiology of the endothelium, especially related to the synthesis and function of nitric oxide. We also discuss the pathophysiology of vascular disease associated with DM. This includes the role of hyperglycemia in the induction of oxidative stress and the role of advanced glycation end-products. We also consider therapeutic strategies.

Effects of acid-base imbalance on vascular reactivity

Acid-base homeostasis maintains systemic arterial pH within a narrow range. Whereas the normal range of pH for clinical laboratories is 7.35-7.45, in vivo pH is maintained within a much narrower range. In clinical and experimental settings, blood pH can vary in response to respiratory or renal impairment. This altered pH promotes changes in vascular smooth muscle tone with impact on circulation and blood pressure control. Changes in pH can be divided into those occurring in the extracellular space (pHo) and those occurring within the intracellular space (pHi), although, extracellular and intracellular compartments influence each other. Consistent with the multiple events involved in the changes in tone produced by altered pHo, including type of vascular bed, several factors and mechanisms, in addition to hydrogen ion concentration, have been suggested to be involved. The scientific literature has many reports concerning acid-base balance and endothelium function, but these concepts are not clear about acid-base disorders and their relations with the three known mechanisms of endothelium-dependent vascular reactivity: nitric oxide (NO/cGMP-dependent), prostacyclin (PGI2/cAMP-dependent) and hyperpolarization. During the last decades, many studies have been published and have given rise to confronting data on acid-base disorder and endothelial function. Therefore, the main proposal of this review is to provide a critical analysis of the state of art and incentivate researchers to develop more studies about these issues.

Effects of an inspiratory muscle rehabilitation program in the postoperative period of cardiac surgery

FUNDAMENTO: Los musculos respiratorios se ven afectados tras operaciones cardiacas. OBJETIVO: Verificar si el condicionamiento preoperatorio de los musculos inspiratorios podria ayudar a disminuir la disfuncion respiratoria postoperatoria. METODOS: Se dividieron en dos grupos, y de forma randomica, a 30 voluntarios -de ambos sexos, con edad minima de 50 ano- que aguardaban cirugia de revascularizacion del miocardio y/o cirugia de valvula cardiaca. Se incluyo a un total de 15 pacientes en un programa domiciliar, de por lo menos 2 semanas de entrenamiento preoperatorio de los musculos inspiratorios, utilizandose un dispositivo con una carga correspondiente al 40% de la presion inspiratoria maxima. Los otros 15 individuos recibieron orientaciones generales y no entrenaron los musculos inspiratorios. Tanto la espirometria, antes y luego del programa de entrenamiento, asi como la evolucion de los gases sanguineos arteriales y de las presiones inspiratoria y espiratoria maximas, se las evaluaron en ambos grupos antes y tras la cirugia. Se compararon tambien los desenlaces clinicos de los dos grupos. RESULTADOS: Observamos que el entrenamiento de los musculos inspiratorios aumento la capacidad vital forzada, la ventilacion voluntaria maxima y la relacion entre el volumen espirado forzado en el primer segundo y la capacidad vital forzada. La evolucion de los gases sanguineos y de las presiones espiratoria e inspiratoria maximas antes y tras la cirugia se mostro similar en ambos grupos, con desenlaces tambien similares. CONCLUSION: Concluimos que nuestro programa domiciliar de entrenamiento de los musculos inspiratorios fue seguro y produjo la mejora de la capacidad vital forzada y la ventilacion voluntaria maxima, aunque los beneficios clinicos de ese programa no han sido claramente demostrados en el presente estudio.BACKGROUND Respiratory muscles are affected after cardiac surgeries. OBJECTIVE To verify whether the preoperative conditioning of the inspiratory muscles might help to decrease postoperative respiratory dysfunction. METHODS Thirty volunteers of both genders and with a minimum age of 50 years, while waiting for myocardial revascularization and/or cardiac valve surgery, were randomly assigned to two groups. Fifteen patients were included in a domiciliary program of at least 2 weeks of preoperative training of the inspiratory muscles, using a device with a load corresponding to 40% of the maximum inspiratory pressure. The other 15 patients received general advice and did not train the inspiratory muscle. Spirometry, before and after the training program, as well as the evolution of the arterial blood gases and of the maximum inspiratory and expiratory pressure, before and after the operation were evaluated in both group. The clinical outcomes of the two groups were also compared. RESULTS We observed that inspiratory muscle training increased the forced vital capacity, the maximum voluntary ventilation and the ratio between the forced expired volume during the first second and the forced vital capacity. The evolution of the arterial blood gases and of the maximum inspiratory and expiratory pressures before and after the operation was similar in both groups, with the outcomes also being similar. CONCLUSION We concluded that our domiciliary program of inspiratory muscle training was safe and improved the forced vital capacity and the maximum voluntary ventilation, although the clinical benefits of this program were not clearly demonstrable in the present study.

Cardiac tamponade: An unusual complication of pericardial cyst

Pericardial cysts are not common and rarely cause symptoms. We report a unique case of a 15-year-old male patient with cardiac tamponade clinically diagnosed who was referred for echocardiography. Transthoracic echocardiography revealed, in addition to a large pericardial effusion associated with echocardiographic signs of cardiac tamponade, an 8 x 5 cm echofree image suggesting a pericardial cyst adjacent to the right atrium. Immediately after pericardiocentesis, yielding a serosanguinous liquid, the patient showed striking clinical improvement and echocardiography demonstrated minimal pericardial effusion with persistence of the cystic image. At surgery a pericardial cyst containing a sanguinous fluid was found and the pathologic findings were consistent with hematic pericardial cyst. Thus echocardiography played a fundamental role for the diagnosis and treatment of the rare complication of a pericardial cyst documented in this patient.

Risk factors for acute renal failure after heart surgery

OBJECTIVE The aim of the present study was to identify risk factors for acute renal failure in patients with normal levels of serum creatinine who had undergone coronary artery bypass graft (CABG) surgery and/or valve surgery. METHODS Data from a cohort of 769 patients were assessed using bivariate analyses and binary logistic regression modeling. RESULTS Three hundred eighty one patients underwent CABG, 339 valve surgery and 49 had undergone both simultaneously. Forty six percent of the patients were female and the mean age was 57 +/- 14 years (13 to 89 years). Seventy eight (10%) patients presented renal dysfunction postoperatively, of these 23% needed hemodialysis (2.4% of all patients). The mortality for the whole cohort was 10%. The overall mortality for patients experiencing postoperative renal dysfunction was 40% (versus 7%, P < 0.001), 29% for those who did not need dialysis and 67% for those who needed dialysis (P = 0.004). The independent risk factors found were: age (P < 0.000, OR: 1.056), congestive heart failure (P = 0.091, OR: 2.238), COPD (P = 0.003, OR: 4.111), endocarditis (P = 0.001, OR: 12.140), myocardial infarction < 30 days (P = 0.015, OR: 4.205), valve surgery (P = 0.016, OR: 2.137), cardiopulmonary bypass time > 120 min (P = 0.001, OR: 7.040), peripheral arterial vascular disease (P = 0.107, 2.296). CONCLUSION Renal dysfunction was the most frequent postoperative organ dysfunction in patients undergone CABG and/or valve surgery and age, congestive heart failure, COPD, endocarditis, myocardial infarction < 30 days, valve surgery, cardiopulmonary bypass time >120 min, and peripheral arterial vascular disease were the risk factors independently associated with acute renal failure (ARF).

Oxidative-Stress Biomarkers in Patients with Pulmonary Hypertension

This controlled, prospective, nonrandomized clinical investigation has as its chief strength the fact that it was done in humans with active disease and apparently on fairly modest therapeutic regimens. The aim was to present the results of oxidative-stress biomarkers in humans suffering from pulmonary artery hypertension (PAH). Inflammation and oxidative stress are essential in PAH with increased lipid peroxidation and reduced antioxidant defenses. Twenty-four adult patients of both sexes, with a mean age of 21 years, were subdivided into 2 groups: a control group of 12 healthy, nonsmoking volunteers and a PAH group (PAHG) of 12 volunteers with PAH receiving outpatient treatment. Oxidative stress was evaluated by plasma activity of reduced glutathione (GSH); lipid peroxidation was expressed by malondialdehyde (MDA) and lipid hydroperoxide (ferrous oxidation of xylenol orange [FOX] assay); vitamin E was measured by high-performance liquid chromatography and tumor necrosis factor-α (TNF-α) by enzyme-linked immunosorbent assay. Statistical analyses showed significant differences for (1) the TNF-α measure, with highest values in PAHG patients; (2) the plasma GSH, with lowest values in PAHG patients; (3) vitamin E, with the lowest concentrations in PAHG patients; (4) MDA measure, with highest values in PAHG patients; and (5) the lipid hydroperoxide FOX measure, with highest values in PAHG patients. In conclusion, inflammation and oxidative stress are present in patients with PAH, as confirmed by increased lipid peroxidation, reduced GSH, and low concentrations of vitamin E.

Efeitos de um programa de reabilitação da musculatura inspiratória no pós-operatório de cirurgia cardíaca

FUNDAMENTO: Los musculos respiratorios se ven afectados tras operaciones cardiacas. OBJETIVO: Verificar si el condicionamiento preoperatorio de los musculos inspiratorios podria ayudar a disminuir la disfuncion respiratoria postoperatoria. METODOS: Se dividieron en dos grupos, y de forma randomica, a 30 voluntarios -de ambos sexos, con edad minima de 50 ano- que aguardaban cirugia de revascularizacion del miocardio y/o cirugia de valvula cardiaca. Se incluyo a un total de 15 pacientes en un programa domiciliar, de por lo menos 2 semanas de entrenamiento preoperatorio de los musculos inspiratorios, utilizandose un dispositivo con una carga correspondiente al 40% de la presion inspiratoria maxima. Los otros 15 individuos recibieron orientaciones generales y no entrenaron los musculos inspiratorios. Tanto la espirometria, antes y luego del programa de entrenamiento, asi como la evolucion de los gases sanguineos arteriales y de las presiones inspiratoria y espiratoria maximas, se las evaluaron en ambos grupos antes y tras la cirugia. Se compararon tambien los desenlaces clinicos de los dos grupos. RESULTADOS: Observamos que el entrenamiento de los musculos inspiratorios aumento la capacidad vital forzada, la ventilacion voluntaria maxima y la relacion entre el volumen espirado forzado en el primer segundo y la capacidad vital forzada. La evolucion de los gases sanguineos y de las presiones espiratoria e inspiratoria maximas antes y tras la cirugia se mostro similar en ambos grupos, con desenlaces tambien similares. CONCLUSION: Concluimos que nuestro programa domiciliar de entrenamiento de los musculos inspiratorios fue seguro y produjo la mejora de la capacidad vital forzada y la ventilacion voluntaria maxima, aunque los beneficios clinicos de ese programa no han sido claramente demostrados en el presente estudio.BACKGROUND Respiratory muscles are affected after cardiac surgeries. OBJECTIVE To verify whether the preoperative conditioning of the inspiratory muscles might help to decrease postoperative respiratory dysfunction. METHODS Thirty volunteers of both genders and with a minimum age of 50 years, while waiting for myocardial revascularization and/or cardiac valve surgery, were randomly assigned to two groups. Fifteen patients were included in a domiciliary program of at least 2 weeks of preoperative training of the inspiratory muscles, using a device with a load corresponding to 40% of the maximum inspiratory pressure. The other 15 patients received general advice and did not train the inspiratory muscle. Spirometry, before and after the training program, as well as the evolution of the arterial blood gases and of the maximum inspiratory and expiratory pressure, before and after the operation were evaluated in both group. The clinical outcomes of the two groups were also compared. RESULTS We observed that inspiratory muscle training increased the forced vital capacity, the maximum voluntary ventilation and the ratio between the forced expired volume during the first second and the forced vital capacity. The evolution of the arterial blood gases and of the maximum inspiratory and expiratory pressures before and after the operation was similar in both groups, with the outcomes also being similar. CONCLUSION We concluded that our domiciliary program of inspiratory muscle training was safe and improved the forced vital capacity and the maximum voluntary ventilation, although the clinical benefits of this program were not clearly demonstrable in the present study.

Avaliação da ventilação não-invasiva com dois níveis de pressão positiva nas vias aéreas após cirurgia cardíaca

INTRODUCTION: The application of two levels of ventilation by positive pressure (BiPAP®) associated with conventional respiratory therapy (CRT) in postoperative periord of cardiac surgery may contribute to reduction of pulmonary complications. OBJECTIVES: To evaluate the safety and compliance of preventive application of BiPAP® CRT associated with immediate postoperative myocardial revascularization. METHODS: 26 patients undergoing coronary artery bypass grafting were randomly allocated in one of the groups. Patients of the Control Group (CG) were treated only with conventional respiratory therapy, compared to BiPAP group (BG) (in addition to conventional respiratory therapy the patients were subjected to 30 minutes of ventilation by two levels twice a day). The conventional respiratory therapy was held in both groups, twice a day. All patients were evaluated for vital capacity, airway permeability, maximal respiratory pressures, oxygen saturation, heart rate, respiratory frequency, Volume Minute, tidal volume, systolic and diastolic blood pressure. Evaluations were performed during hospitalization preoperatively, immediately after extubation, 24h and 48h after extubation. RESULTS: In CG 61.5% of patients had some degree of atelectasias, in comparison to 54% of BG (P=0.691). The vital capacity was higher in the GB postoperatively (P<0.015). All the other ventilometric, gasometric, hemodynamic and manometric parameters were similar between groups. CONCLUSION: Coronary artery bypass grafting leads to deterioration of respiratory function postoperatively, and the application of positive pressure ventilation (BiPAP®) may be beneficial to restore lung function more quickly, especially vital capacity, safely, and well accepted by patients due to greater comfort with the sensation of pain during the execution of respiratory therapy.

Nitric oxide and prostacyclin in ultrasonic vasodilatation of the canine internal mammary artery

BACKGROUND Investigators recently demonstrated increased free blood flow from radial artery free grafts harvested using ultrasonic technology. We investigated the mechanism underlying this phenomenon. METHODS Canine internal mammary artery segments (with and without intact endothelium) were precontracted with norepinephrine and sonicated 3 seconds in organ chambers with ultrasonic coagulating shears (Harmonic Scalpel; Ethicon Endo-Surgery, Cincinnati, OH) functioning at level 2. Vessel tension was continuously measured to examine vasoactivity in response to sonication alone (control) or with N(ù)-Nitro-l-arginine (l-NNA) and indomethacin added to the chamber medium individually or in combination. Tissue heating, acoustic pressure, and endothelial damage as detected by scanning electron micrography were also assessed. RESULTS In vitro sonication with the Harmonic Scalpel induced predominately endothelium-dependent internal mammary artery vasorelaxation but a small endothelium-independent contribution was also observed. Early vasorelaxation (1 minute after stimulus) was maximally inhibited by l-NNA alone and in combination with indomethacin. Relaxation during this period was insignificantly affected by indomethacin alone. Only the combination of l-NNA and indomethacin maximally inhibited late vasorelaxation (5 minutes after stimulus), whereas inhibitory effects of l-NNA diminished during this time period. Indomethacin inhibited relaxation substantially during this phase, although significantly less than did l-NNA alone. The Harmonic Scalpel minimally heated the tissue surface (0.3 +/- 0.03 degrees C) and did not disrupt endothelial cell integrity while operating at 50 mW/cm(2) intensity (acoustic pressure 40 kPa). CONCLUSIONS Sonication induces vasorelaxation almost completely by time-dependent endothelial nitric oxide and prostacyclin release, which appears unrelated to tissue heating or endothelial architectural disruption.