Deep breathing exercises are widely used in the postoperative care to prevent or reduce pulmonary complications, but no scientific evidence for the efficacy has been found after coronary artery bypass grafting (CABG) surgery. The aim of the thesis was to describe postoperative pulmonary function and to evaluate the efficacy of deep breathing exercises performed with or without a blow bottle device for positive expiratory pressure (PEP) 10 cmH2O or an inspiratory resistance-positive expiratory pressure (IR-PEP) mask with an inspiratory pressure of -5 cmH2O and an expiratory pressure of +10 to +15 cmH2O. Patients undergoing CABG were instructed to perform 30 slow deep breaths hourly during daytime for the first four postoperative days. Patient management was similar in the groups, except for the different breathing techniques. Measurements were performed preoperatively, on the fourth postoperative day and four months after surgery. The immediate effect of the deep breathing exercises was examined on the second postoperative day. Pulmonary function was assessed by spirometry, diffusion capacity for carbon monoxide and arterial blood gases. Atelectasis was determined by chest roentgenograms or spiral computed tomography (CT). Lung volumes were markedly reduced on the fourth postoperative day. Four months after surgery the pulmonary function was still significantly reduced. On the second and fourth postoperative day all patients had atelectasis visible on CT. A single session of deep breathing exercises performed with or without a mechanical device caused a significant reduction in atelectasis and an improvement in oxygenation. No major differences between deep breathing performed with or without a blow bottle or IR-PEP-device were found, except for a lesser decrease in total lung capacity in the blow bottle group on the fourth postoperative day. Patients who performed deep breathing exercises after CABG had significantly smaller atelectasis and better pulmonary function on the fourth postoperative day compared to a control group who performed no exercises.

The primary aim was to register the incidence of surgical wound infections (SWI) in sternotomy and leg incisions and potential risk factors for SWI following coronary artery by-pass graft (CAGB) procedures. Patients’ perspectives of SWI and the subsequent treatment were also considered. Risk factors were registered for 374 patients. Patients were contacted by telephone 30 and 60 days after surgery and interviewed according to a questionnaire about symptoms and signs of wound infections. SWI was defined according to The Centers for Disease Control. Patients with mediastinitis were also interviewed within four months about how they experienced care, how they coped and how they thought the mediastinitis would influence their future life. SWIs were diagnosed in 30 % of the patients. Seventy-three percent of the SWIs of the leg were diagnosed within 30 days of surgery and 27% were diagnosed within 31 to 60 days. Female gender and use of a monofilament suture for skin closure were the most important risk factors for SWI of the leg. Low preoperative haemoglobin concentration was the most important risk factor for sternal SWI. Patients with mediastinitis had higher BMI and had more often received erythrocyte transfusions on postoperative day 2 or later than those without infections. Patients without a diagnosis of diabetes who had increased blood glucose concentrations during the intermediate postoperative period had an increased risk of mediastinitis. It was not possible to separate the effect of diabetes as a risk factor for SWI from that of hyperglycaemia as such. Patients’ experiences were influenced by the staffs’ medical knowledge, how care was given and how well information was provided. Perceived danger and stress influenced how they coped with the situation. The patients believed that the mediastinitis would not affect the final outcome of the CABG procedure, even though their confidence in this was influenced by uncertainties about the rehabilitation process.

Neuropsychological impairment following cardiopulmonary bypass (CPB) remains a serious consequence of otherwise successful surgery. The incidence of neuropsychological decline is poorly understood due to varied measurement intervals, and perhaps more importantly the use of unreliable detection and classification methods. The reported incidence varies considerably, ranging anywhere from 30% to 90% of subjects. While the nature of this impairment has not been fully elucidated, recent evidence suggests that microembolism during surgery may be the principal causative agent of postoperative cerebral dysfunction. The work described in this thesis investigates one possible source of microembolism leading to postoperative decline, namely thromboembolism arising from excessive activation of the haemostatic mechanism. Crucial to the accurate detection of significant decline in individual patients, this work also focuses on the development and use of meaningful criteria to be used when describing change in neuropsychological performance measures. The strong haemostatic activation during CPB is controlled by heparin anticoagulation. The clinical performance of the Hepcon heparin-monitoring instrument was compared to the activated clotting time (ACT), which is used in most cardiac centres. An analysis of samples from 42 elective coronary artery bypass grafting (CABG) patients shows that the ACT does not detect the significant decline in heparin concentration seen upon connection to CPB, in comparison to the Hepcon. The Hepcon appears to be in satisfactory agreement with laboratory anti-Xa analysis of heparin concentration, with the mean difference for the Hepcon at -0.46 U/ml, and the limits of agreement +/- 1.12 U/ml. Further analysis shows that that for 95% of cases, the Hepcon will give values that are between 0.53 and 1.27 times the value for anti-Xa. The loss of relationship between ACT and heparin concentration was further investigated by converting ACT values to heparin concentration. The results provide data on the degree of prolongation in ACT times brought about by factors associated with CPB. A methodology is presented by which users can adjust for the loss of relationship between ACT and heparin. This work also demonstrates that under normal usage of the ACT, the user may obtain values up to 3 times appropriate for the plasma heparin concentration. The computer-administered neuropsychological testing tool (the MicroCog) was validated using 40 age-matched control subjects. Using a two-week interval, the summary score correlation coefficients ranged from .49 to .84, with all scores demonstrating significant practice effects. Also presented are retest normative data that may be used to determine significant change in a homogeneous sample using both reliable change and regression models of analysis. The performance of four different models of change analysis was then analysed using data from the clinical group. The regression technique of analysis was shown to be the most useful prediction model as it provides correction for both practice effects and regression toward the mean in each individual. A novel statistical rationale is presented for the choice of criteria in the identification of patients that may be defined as overall impaired when using a battery of test scores. When using one-tailed prediction models for decline, the binomial distribution of scores was shown to be a useful descriptive statistic providing an estimate of change due to chance. When applied to a suitable selection of scores that minimise shared variance, a value +/- 20% of test scores used was demonstrated to be a rational cut-off for an individual to be classified as impaired. Using this methodology, 32.7% of patients were identified as significantly deteriorated in neuropsychological test function immediately prior to discharge from hospital. Patient age was shown to be a significant predictor of neuropsychological decline following CPB. No significant relationship was identified between thrombin generation and neuropsychological change scores, however problems with patient recruitment and retention limited the statistical power of this study. An intriguing relationship with heparin concentration was noted that might warrant further investigation. This work highlights the complex nature of post-bypass neuropsychological dysfunction and the complexities in assessing decline. The regression-based model was shown to be highly useful in the analysis of data from a suitably validated neuropsychological testing tool. The argument that no suitable criterion exists for the identification of patients as overall impaired has been challenged with the development of a rational cut-off based on the likely distribution of change scores across a series. The work presented here confirms the need for standardised testing methods based on sound statistical criteria. This work also highlights the problems associated with current methods for monitoring anticoagulation therapy during bypass surgery. Methodology is presented that allows adjustment of ACT results to account for CPB-induced prolongation of clotting times. Current techniques for heparin monitoring overestimate heparin levels on bypass by up to threefold, which may predispose to subclinical coagulation and increased delivery of protamine.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.

Diss. (sammanfattning) Linköping : Univ., 2001. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Univ., 2002. / Härtill 6 uppsatser.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 4 uppsatser.

Objective: Compare the evolution regarding the complications concerning two types of incision (conventional x mini-incision), for saphenectomy in patients that go under myocardial revascularization or otherwise known as coronary artery bypass surgery. Methods: During the period from January 2012 to August 2013, 66 patients were prospectively selected for coronary artery bypass with cardiopulmonary bypass surgery. These were divided into two groups: Conventional and Mini-Incision, with 33 patients in each group chosen in a random fashion and with knowledge of which technique to be used being presented only at the start of the surgery. In the conventional group, the patients received an incision to the lower member of 7 to 10 centimeters. The patients in the Mini-Incision group received an incision to the lower member of 3 to 4 centimeters, both performed without the use of any special material for harvesting the saphenous vein. Results: The groups were similar in terms of clinical data and in the preoperative period. Males made up a greater part of the group with 63.7% and 81.9% in groups C and M, respectively. Among the complications of the analysed surgical areas, edema (p = 0.011), hematoma (p = 0.020), dehiscence (p = 0.012) and infection (p = 0.012), were significantly greater in group C when compared to group M. When the matter comes to the variable in relation to the risk of Surgical Site Infections (SSI), no significant difference was found between the groups. Conclusion: Coronary artery bypass surgery with mini-incision for saphenectomy, demonstrated a lower rate for preoperative complications, such as edema, hematoma, dehiscence and infection, when compared to saphenectomy under conventional incision procedures. / Objetivo: Comparar a evolução quanto às complicações de dois tipos de incisão (convencional X miniincisão) para safenectomia em pacientes que se submeteram à cirurgia de Revascularização do Miocárdio. Métodos: No período de janeiro de 2012 a agosto de 2013, 66 pacientes foram selecionados, prospectivamente, para cirurgia de revascularização do miocárdio com circulação extracorpórea. Estes foram distribuídos em dois grupos: Convencional e Miniincisão, com 33 pacientes em cada grupo de forma randomizada e conhecimento da técnica apenas no início da cirurgia. No grupo Convencional, os pacientes receberam uma incisão no membro inferior de 7 a 10 centímetros. Os pacientes do grupo Miniincisão receberam uma incisão no membro inferior de 3 a 4 centímetros, ambos sem o uso de material especial para a colheita da veia safena. Resultados: Os grupos eram semelhantes quanto aos dados clínicos de pré-operatório. Houve predominância do sexo masculino, 63,7% e 81,9% nos grupos C e M respectivamente. Dentre as complicações do sítio cirúrgico analisadas, o edema (p = 0,011), hematoma (p = 0,020), deiscência (p = 0,012) e infecção (p = 0,012), foram significativamente maiores no grupo C comparado com o grupo M. Quando tratamos a variável infecção em relação ao Índice de Risco para Infecção Cirúrgica (IRIC), não houve diferença significante entre os grupos. Conclusão: A cirurgia de revascularização do miocárdio com miniincisão para safenectomia demonstrou um menor índice de complicações pós-operatórias como edema, hematoma, deiscência e infecção quando comparado com a safenectomia com incisão convencional. / Mestre em Ciências da Saúde

INTRODUÇÃO: A cirurgia de revascularização miocárdica sem utilização de circulação extracorpórea (CEC) tem sido cada vez mais utilizada, especialmente após a introdução de dispositivos estabilizadores da parede cardíaca. Entretanto, a técnica pode causar alterações hemodinâmicas durante a realização das anastomoses coronárias. OBJETIVOS: Analisar as alterações hemodinâmicas decorrentes das mudanças de posição do coração para abordar as artérias coronárias sem CEC e comparar os monitores de débito cardíaco semi-contínuo e de ecodoppler transesofágico quanto à precisão das medidas hemodinâmicas. MATERIAL E MÉTODOS: Foram selecionados aleatoriamente 20 pacientes adultos com idade inferior a 80 anos, candidatos a cirurgia eletiva de revascularização miocárdica sem utilização de circulação extracorpórea. A avaliação hemodinâmica incluiu a utilização de ecodopppler com transdutor esofágico e de cateter de artéria pulmonar com filamento térmico. A coleta de dados foi realizada: 1 - após a indução da anestesia, antes do início da revascularização propriamente dita, 2 - durante a realização das anastomoses distais, logo após o posicionamento e estabilização do coração e 3 - após cinco minutos do início da anastomose. Os dados hemodinâmicos foram analisados por análise de variância de duplo fator com repetição, complementada por teste de Newman-Keuls. O nível de significância considerado foi de 5%. Os valores de débito cardíaco foram comparados segundo método proposto por Bland e Altman, analisando a correlação intraclasses, diferenças médias e intervalos de confiança de 95%. RESULTADOS: Alterações hemodinâmicas significativas foram detectadas para o aumento de pressão de oclusão de artéria pulmonar (de 17,7 ± 6,1 para 19,2 ± 6,5 mmHg - p<0,001 e para 19,4 ± 5,8 mmHg - p<0,001) e pressão venosa central (de 13,9 ± 5,4 para 14,9 ± 5,9 mmHg - p=0,007 e para 15,1 ± 6,0 mmHg - p=0,006), além de diminuição do débito cardíaco obtido por termodiluição intermitente (de 4,70 ± 1,43 para 4,23 ± 1,22 L/min - p<0,001 e para 4,26 ± 1,27 L/min - p<0,001). Houve interação grupo-tempo estatisticamente significativa no débito cardíaco por Doppler esofágico, que apresentou redução no grupo lateral de 4,08 ± 1,99 para 2,84 ± 1,81 L/min (p=0,02) e para 2,86 ± 1,73 L/min (p=0,02), e no fluxo sanguíneo aórtico, que diminuiu de 2,85 ± 1,39 para 1,99 ± 1,26 L/min (p=0,02) e para 2,00 ± 1,21 L/min (p=0,02). As medidas de débito cardíaco intermitente, semicontínuo e por Doppler esofágico apresentaram diferenças médias e intervalos de confiança de 95% acima de limites aceitáveis clinicamente. CONCLUSÕES: Houve deterioração hemodinâmica significativa durante a revascularização miocárdica sem CEC. Pelo Doppler esofágico, o débito cardíaco apresentou redução detectada apenas na parede lateral. As diferenças nos valores de débito cardíaco foram muito amplas para considerar os métodos concordantes, em quaisquer das condições hemodinâmicas estudadas. / INTRODUCTION: Coronary artery bypass graft (CABG) surgeries have been performed increasingly without cardiopulmonary bypass (off-pump CABG), specially with introduction of cardiac wall stabilizing devices. However, hemodynamic changes can occur during coronary anastomosis. OBJECTIVES: To study hemodynamic alterations caused when cardiac position is changed to operate coronary arteries and to compare continuous cardiac output and esophageal Doppler monitor regardig accuracy of hemodynamic measurements. MATERIALS AND METHODS: Twenty adult patients under age of 80 undergoing elective off-pump CABG were enrolled. Hemodynamic evaluation was performed with esophageal echodoppler and continuous thermodilution pulmonary artery catheter. Data were collected 1 - after induction of anesthesia, before revascularization, 2 - during distal anastomosis, right after heart positioning and stabilization, and 3 - five minutes following the beginning of anastomosis. Repeated measures two-way ANOVA with post hoc Newman-Keuls tests were used to analyse hemodynamic data and level of significance was set at 0.05. Cardiac output values were compared using the method proposed by Bland and Altman, and included analysis of correlation, mean differences and 95% confidence intervals. RESULTS: Significant hemodynamic alterations were detected during revascularization of coronary arteries as elevation of pulmonary artery occlusion pressure (from 17.7 ± 6.1 to 19.2 ± 6.5 mmHg - P <0.001, and to 19.4 ± 5.8 mmHg - P <0.001) and of central venous pressures (from 13.9 ± 5.4 to 14.9 ± 5.9 mmHg - P =0.007, and to 15.1 ± 6.0 mmHg - P =0.006), and as reduction of intermittent cardiac output (from 4.70 ± 1.43 to 4.23 ± 1.22 l/min - P <0.001, and to 4.26 ± 1.27 l/min - P <0.001). Statistically significant group-time interaction was observed in esophageal Doppler cardiac output, that decreased in the lateral wall from 4.08 ± 1.99 to 2.84 ± 1.81 l/min (P =0.02) and to 2.86 ± 1.73 l/min (P =0.02), and in aortic blood flow, that decreased from 2.85 ± 1.39 to 1.99 ± 1.26 l/min (P =0,02) and to 2.00 ± 1.21 l/min (P =0.02). Intermittent, STAT-mode or esophageal Doppler cardiac output mean differences and 95% confidence intervals were beyond clinically acceptable limits. CONCLUSIONS: There was significant hemodynamic deterioration during off-pump CABG. On the esophageal Doppler monitor, cardiac output decrease was detected only in the lateral wall. Differences in cardiac output measurements were too wide to say methods agreed, in all hemodynamic conditions studied.

INTRODUÇÃO E OBJETIVOS: A Circulação extracorpórea (CEC) é associada a ativação leucocitária, resposta inflamatória e disfunção pulmonar. Objetivou-se avaliar os efeitos da filtragem leucocitária sobre a resposta inflamatória e a função pulmonar em indivíduos submetidos à revascularização do miocárdio (RM) com CEC. MÉTODO: Após aprovação pelo Comitê de Ética Institucional e obtenção do consentimento informado dos indivíduos, foi realizado estudo prospectivo randomizado, para comparar indivíduos adultos submetidos à RM com CEC, utilizando-se filtragem leucocitária (n=09) ou filtro standard (n=11) durante a CEC. Tomografia computadorizada (CT) de tórax, espirometria, análise da oxigenação e hemograma foram realizados antes da cirurgia. A anestesia foi induzida por via venosa com etomidato (0,3 mg.kg-1), sufentanil (0,3 ug.kg-1), pancurônio (0,08 mg.kg-1) e mantida com isoflurano (0,5 - 1,0 CAM) e sufentanil (0,5 ug.kg-1.h-1). A ventilação mecânica utilizou volume corrente de 8 mL.kg-1, com FiO2 de 0,6 e PEEP de 5 cm H2O, exceto durante a CEC. No grupo Filtragem, durante a CEC, foi inserido um filtro de leucócitos na linha arterial do circuito (LG-6, Pall Biomedical Products) e, no grupo Controle, foi utilizado o filtro Standard. Contagem leucocitária foi realizada após a indução, aos 5, 25 e 50 min de CEC, ao final da cirurgia, com 12 e 24 h PO. Dados hemodinâmicos, PaO2/FiO2, fração de Shunt, interleucinas, elastase e mieloperoxidase foram colhidos antes e após a CEC, no final da cirurgia, com 6,12 e 24 h PO. Trinta minutos depois da indução, e trinta após a CEC, três amostras sequenciais de ar exalado foram colhidas para análise de óxido nítrico (NO), por quimiluminescência. Espirometria e CT de tórax foram realizadas no primeiro dia pós-operatório. Os dados foram analisados por meio de ANOVA de duplo fator para medidas repetidas. RESULTADOS: O tempo de CEC foi similar entre os grupos controle e filtragem (86,78 ± 19,58 versus 104,64 ± 27,76 min, p=0,161). O grupo Filtragem mostrou menor contagem leucocitária que o grupo Controle até 50 min de CEC (3384 ± 2025 versus 6478 ± 3582 U.mm-3 U.mm-3, p=0,036), menor fração de shunt até 6 h PO (10 ± 2% versus 16 ± 5%, p=0,040) e menores níveis de IL-10 até o final da cirurgia (1571 ± 1137 pg.mL-1 versus 3108 ± 1694 pg.mL-1, p=0,031). Não houve diferença estatisticamente significativa entre os grupos em relação ao restante dos parâmetros avaliados (p > 0,05). CONCLUSÕES: A filtragem leucocitária durante a CEC, quando comparada à utilização de filtro convencional, promove diminuição da contagem de neutrófilos até 50 minutos de CEC, menor liberação de IL-10 até o final da cirurgia e menor alteração da fração de shunt intrapulmonar até 6 h PO, protegendo os pulmões apenas temporariamente contra a injúria aguda relacionada / BACKGROUND AND OBJECTIVE: The Cardiopulmonary bypass (CPB) is related to leukocyte activation, inflammatory response and lung dysfunction. The aim of this study was to evaluate the effects of CPB-leukocyte filtration on the inflammatory response and lung function after coronary artery bypass grafting (CABG). METHODS: After approval by the institutional ethics committee and informed consent, a prospective randomized study was performed to compare CABG-patients undergoing CPB-leukocyte filtration (n=9) or standard CPB (n=11). Espirometry, chest computed tomography (CT), oxygenation analysis and leukocyte count were performed before surgery. Anesthesia induction was performed intravenously with etomidate (0,3 mg.kg-1), sufentanil (0,3 ug.kg-1), pancuronium bromide (0,08 mg.kg-1) e sustained with isoflurano (0,5 - 1,0 CAM) and sufentanil (0,5 ug.kg-1.h-1). The tidal volume used during mechanical ventilation was 8 mL.kg-1, the FiO2 0.6 and PEEP 5 cm H2O, except during CPB. In Filtered group, during CPB, was inserted a leukocyte filter in the arterial line of CPB circuit (LG-6, Pall Biomedical Products) and, in Control group, the Standard arterial line filter was utilized. Hemodynamic data, PaO2/FiO2, shunt fraction, interleukins, elastase and myeloperoxidase were evaluated before and after CPB, at the end of surgery, and 6, 12 and 24 h PO. Thirty minutes after induction, and Thirty after CPB, three sequential exhaled air samples were collected to perform analysis of nitric oxide (NO), by chemiluminescence technique. Espirometry and chest CT were performed on first PO. Data were analyzed using two-factor ANOVA for repeated measurements. RESULTS: Length of CPB was similar in the filtered and control groups (86.78 ± 19.58 versus 104.64 ± 27.76 min, p = 0.161). The filtered group showed lower neutrophil counts than the control group up to 50 minutes of CPB (3384 ± 2025 versus 6478 ± 3582 U/mm-3, p = 0.036), lower shunt fraction up to 6 hours after surgery (10 ± 2% versus 16 ± 5%, p = 0.040), and lower levels of IL-10 at the end of surgery (1571 ± 1137 pg.ml-1 versus 3108 ± 1694 pg.ml-1, p = 0.031). There were no significant differences between the groups with respect to rest of the parameters evaluated (p >u0,05). CONCLUSIONS: The leukocyte filtration during CPB, when compared to the use of conventional filter, promotes lower neutrophil counts up to 50 minutes of CPB, lower levels of IL-10 at the end of surgery and lower shunt fraction up to 6 hours after surgery, protecting the lungs only temporarily against the acute injury related Trial registration: Clinicaltrials.gov identifier: NCT01469676