R. Oliveira

Lesão pulmonar e ventilação mecânica em cirurgia cardíaca: revisão

Respiratory failure after cardiopulmonary bypass heart surgery can result from many pre-, intra- or postoperative respiratory system-related factors. This review was aimed to discuss some factors related to acute lung injury observed during the postoperative period of cardiac surgery and the mechanical ventilation modalities which should be considered to prevent hypoxemia.

Effects of manual chest compression and descompression maneuver on lung volumes, capnography and pulse oximetry in patients receiving mechanical ventilation

OBJECTIVESnThe aims of this study were to evaluate whether there are changes in lung volumes, capnography, pulse oximetry and hemodynamic parameters associated with manual chest compression-decompression maneuver (MCCD) in patients undergoing mechanical ventilation (MV).nnnMETHODnA prospective study of 65 patients undergoing to MV after 24 hours. All patients received bronchial hygiene maneuvers and after 30 minutes they were submitted to ten repetitions of the MCCD during 10 consecutive respiratory cycles in the right hemithorax and than in the left hemithorax. The data were collected before the application of the maneuver and after 1, 5, 10, 15, 20, 25, 30, 35 and 40 minutes following application of the maneuver.nnnRESULTSnThere were statistical significant (p<0.0001) improvements in the following parameters after MCCD maneuver during all phases of data collection until 40 minutes: inspiratory tidal volume (baseline: 458.2±132.1 ml; post 1 min: 557.3±139.1; post 40 min: 574.4±151), minute volume (baseline: 7.0±2.7 L/min; post 1 min: 8.7±3.3; post 40 min: 8.8±3.8), and pulse oximetry (baseline: 97.4±2.2%; post 1 min: 97.9±1,8; post 40 min: 98.2±1.6; p<0.05). There was a reduction in CO2 expired (baseline: 35.1±9.0 mmHg; post 1 min: 31.5±8.2; post 40 min: 31.5±8.29; p<0.0001). There was no statically significant changes in heart rate (baseline: 94.5±20.5 mmHg; post 1 min: 94.7±20.5; post 40 min: 94.92±20.20; p=1) and mean arterial pressure (baseline: 91.2±19.1 bpm; post 1 min: 89.5±17.7; post 40 min: 89.01±16.88; p=0.99). The variables were presented in terms of means and standard deviations.nnnCONCLUSIONnThe MCCD maneuver had positive effects by increasing lung volume and pulse oximetry and reducing CO2 expired, without promoting hemodynamic changes in patients undergoing mechanical ventilation.OBJETIVOS: Avaliar a presenca de alteracoes nos volumes pulmonares, oximetria de pulso, capnografia e alteracoes hemodinâmicas associadas a intervencao da manobra de compressao e descompressao toracica (MCDT) nos pacientes submetidos a ventilacao mecânica (VM). Metodo: Tratou-se de um estudo prospectivo em que foram incluidos 65 pacientes em VM ha mais de 24 horas. O protocolo consistiu na aplicacao de manobras de higiene bronquica e, apos 30 minutos, os pacientes eram submetidos a dez repeticoes da MCDT em dez respiracoes consecutivas no hemitorax direito e, posteriormente, no hemitorax esquerdo, coletando os dados antes e apos a aplicacao da manobra nos tempos 1, 5, 10, 15, 20, 25, 30, 35 e 40 minutos. RESULTADOS: Constatou-se aumento significante (p<0,001) do volume corrente inspiratorio (pre: 458,2±132,1 ml; pos 1 minuto: 557,3±139,1; pos 40 minutos: 574,4±151), volume minuto corrente (pre: 7,0±2,7 L/min; pos 1 minuto: 8,7±3,3; pos 40 minutos: 8,8±3,8) e oximetria de pulso (pre: 97,4±2,2%; pos 1 minuto: 97,9±1,8; pos 40 minutos: 98,2±1,6; p<0,05). Ocorreu reducao no CO2 expirado (pre: 35,1±9,0 mmHg; pos 1 minuto: 31,5±8,2; pos 40 minutos: 31,5±8,29; p<0.0001). Nao houve alteracao significante da frequencia cardiaca (pre: 94,5±20,5 mmHg; pos 1 minuto: 94,7±20,5 e pos 40 minutos: 94,9±20,2; p=1) e pressao arterial media (pre: 91,2±19,1 bpm; pos 1 minuto: 89,5±17,7 e pos 40 minutos: 89,0±16,8; p=0,99). As variaveis foram expressas em media e desvio-padrao. CONCLUSAO: A MCDT possibilita a otimizacao dos volumes pulmonares, da oximetria de pulso e a reducao do CO2 expirado sem promover alteracoes hemodinâmicas significantes nos pacientes submetidos a ventilacao mecânica.

Fator natriurético atrial: ele é o responsável pela hiponatremia e natriurese em neurocirurgia?

Objective: To evaluate the presence of hyponatremia and natriuresis and their association with atrial natriuretic factor in neurosurgery patients. Methods: The study included 30 patients who had been submitted to intracranial tumor resection and cerebral aneurism clipping. Both plasma and urinary sodium and plasma atrial natriuretic factor were measured during the preoperative and postoperative time periods. Results: Hyponatremia was present in 63.33% of the patients, particularly on the first postoperative day. Natriuresis was present in 93.33% of the patients, particularly on the second postoperative day. Plasma atrial natriuretic factor was increased in 92.60% of the patients in at least one of the postoperative days; however, there was no statistically significant association between the atrial natriuretic factor and plasma sodium and between the atrial natriuretic factor and urinary sodium. Conclusion: Hyponatremia and natriuresis were present in most patients after neurosurgery; however, the atrial natriuretic factor cannot be considered to be directly responsible for these alterations in neurosurgery patients. Other natriuretic factors are likely to be involved.Objective To evaluate the presence of hyponatremia and natriuresis and their association with atrial natriuretic factor in neurosurgery patients. Methods The study included 30 patients who had been submitted to intracranial tumor resection and cerebral aneurism clipping. Both plasma and urinary sodium and plasma atrial natriuretic factor were measured during the preoperative and postoperative time periods. Results Hyponatremia was present in 63.33% of the patients, particularly on the first postoperative day. Natriuresis was present in 93.33% of the patients, particularly on the second postoperative day. Plasma atrial natriuretic factor was increased in 92.60% of the patients in at least one of the postoperative days; however, there was no statistically significant association between the atrial natriuretic factor and plasma sodium and between the atrial natriuretic factor and urinary sodium. Conclusion Hyponatremia and natriuresis were present in most patients after neurosurgery; however, the atrial natriuretic factor cannot be considered to be directly responsible for these alterations in neurosurgery patients. Other natriuretic factors are likely to be involved.

Effect of Ultrafiltration on Pulmonary Function and Interleukins in Patients Undergoing Cardiopulmonary Bypass

OBJECTIVEnTo evaluate the effect of ultrafiltration on interleukins, TNF-α levels, and pulmonary function in patients undergoing coronary artery bypass grafting (CABG).nnnDESIGNnProspective, randomized, controlled trial.nnnSETTINGnUniversity hospital.nnnPARTICIPANTSnForty patients undergoing CABG were randomized into a group assigned to receive ultrafiltration (UF) during cardiopulmonary bypass (CPB) or into another group (control) that underwent the same procedure but without ultrafiltration.nnnMETHODSnInterleukins and TNF-α levels, pulmonary gas exchange, and ventilatory mechanics were measured in the preoperative, intraoperative, and postoperative periods. Interleukins and TNF-α also were analyzed in the perfusate of the test group.nnnMEASUREMENTS AND MAIN RESULTSnThere were increases in IL-6 and IL-8 at 30 minutes after CPB and 6, 12, 24, and 36 hours after surgery, along with an increase in TNF-α at 30 minutes after CPB and 24, 36, and 48 hours after surgery in both groups. IL-1 increased at 30 minutes after CPB and 12 hours after surgery, while IL-6 increased 24 and 36 hours after surgery in the UF group. The analysis of the ultrafiltrate showed the presence of TNF-α and traces of IL-1β, IL-6, and IL-8. There were alterations in the oxygen index, alveolar-arterial oxygen difference, deadspace, pulmonary static compliance and airway resistance after anesthesia and sternotomy, as well as in airway resistance at 6 hours after surgery in both groups, with no difference between them.nnnCONCLUSIONSnUltrafiltration increased the serum level of IL-1 and IL-6, while it did not interfere with gas exchange and pulmonary mechanics in CABG.