Postoperative Pulmonary Dysfunction in Adults After Cardiac Surgery With Cardiopulmonary Bypass: Clinical Significance and Implications for Practice

Previous percutaneous coronary intervention increases morbidity after coronary artery bypass grafting

BACKGROUND

We hypothesized that the incidence of previous percutaneous coronary intervention (PCI) is increasing and that prior PCI influences patient morbidity and mortality after coronary artery bypass grafting (CABG).

METHODS

A total of 34,316 patients underwent isolated CABG operations at 16 different statewide, institutions from 2001 to 2008. Patients were stratified into prior PCI (n = 4346; 12.7%) and no prior PCI (n = 29,970). Patient risk factors, intraoperative variables, and outcomes were compared by univariate and multivariate analyses.

RESULTS

The incidence of prior PCI in CABG has risen from <1% to 22.0% from 2001 to 2008 (P < .001). Prior PCI patients were younger (P < .001) and more commonly had previous myocardial infarction (P < .001), but less commonly had heart failure (P < .001). The operative mortality was similar between groups (2.3% vs 1.9%; P = .13). Prior PCI patients had more major complications (15.0% vs 12.0%; P < .001), longer hospitalization (P = .01), and higher readmission rates (P = .01). Importantly, by multivariate analyses, prior PCI was not associated with mortality, but was an independent predictor of major complications after CABG (odds ratio, 1.15; P = .01).

CONCLUSION

The incidence of prior PCI in patients undergoing CABG is increasing. Previous PCI is associated with a higher risk of major complications, greater hospital length of stay, and higher readmission rates after CABG.

A periodized model for exercise improves the intra-hospital evolution of patients after myocardial revascularization: a pilot randomized controlled trial

OBJECTIVE

To compare models of the postoperative hospital treatment phase after myocardial revascularization.

DESIGN

A pilot randomized controlled trial.

SETTING

Hospital patients in a hospital setting.

SUBJECTS

Thirty-two patients with indications for myocardial revascularization were included between January 2008 and December 2009, with a left ventricular ejection fraction (LVEF) ≥50%, 1-second forced expiratory volume (FEV(1)) ≥60 and forced vital capacity (FVC) ≥60% of predicted value.

INTERVENTIONS

Patients were randomly placed into two groups: one performed prescribed exercises according to the model proposed by the American College of Sports Medicine (ACSM) and the other according to a periodized model.

MAIN MEASURES

Partial pressure of O(2) (P o (2)) and arterial O(2) saturation (Sao (2)), percentage of predicted FVC and total distance on the six-minute walking test (6MWT).

RESULTS

Twenty-seven patients were re-evaluated upon release from the hospital (ACSM = 14 and PP = 13). Five patients extubated for more than 6 hours in the postoperative period were excluded from the sample. In the preoperative period the variables P o (2), Sao (2), % FVC and 6MWT were similar. In the postoperative period, a reduction was observed for all parameters in both groups. Upon comparison of the groups, a difference was observed in P o (2) (ACSM = 68.0 ± 4.3 vs. PP = 75.9 ± 4.8 mmHg; P < 0.001), Sao (2) (ACSM = 93.5 ± 1.4 vs. PP = 94.8 ± 1.2%; P = 0.018) and 6MWT (ACSM = 339.3 ± 41.7 vs. PP = 393.8 ± 25.7 m; P < 0.001). There was no difference in % FVC.

CONCLUSION

Patients after myocardial revascularization following a periodized model of exercise presented a better intra-hospital evolution when compared to those using the ACSM model.

Effects of a preoperative individualized exercise program on selected recovery variables for cardiac surgery patients: A pilot study

OBJECTIVE

Research on preoperative individualized exercise prescription (PIEP) for heart surgery patients in Taiwan is lacking. Thus, the purpose of this study was to examine the feasibility of a PIEP in the Taiwanese population.

METHOD

A quasi-experimental design, using purposive sampling, was conducted. Thirty-five patients were recruited, of whom 15 chose to participate in the experimental (PIEP training plus usual care) group, and 20 chose to participate in the control (usual care) group. The effects of the intervention were determined by pulmonary complication-related parameters and quality of life.

RESULTS AND CONCLUSION

The development and process of PIEPs suitable for cardiac patients was described in this study. The results reveal that the two-week exercise-training program contributed to a decreased peak respiratory exchange ratio (RER) after the surgery and earlier ambulation. The effectiveness of PIEPs in improving the quality of life in cardiac surgery patients was validated. This study may also contribute as a reference of the PIEP effect on patients to the healthcare providers.

Pleurotomy with subxyphoid pleural drain affords similar effects to pleural integrity in pulmonary function after off-pump coronary artery bypass graft

BACKGROUND

Exacerbation of pulmonary dysfunction has been reported in patients receiving a pleural drain inserted through the intercostal space in comparison to patients with an intact pleura undergoing coronary artery bypass grafting (CABG). Evidence suggests that shifting the site of pleural drain insertion to the subxyphoid position minimizes chest wall trauma and preserves respiratory function in the early postoperative period. The aim of this study was to compare the pulmonary function parameters, clinical outcomes, and pain score between patients undergoing pleurotomy with pleural drain placed in the subxyphoid position and patients with intact pleural cavity after off-pump CABG (OPCAB) using left internal thoracic artery (LITA).

METHODS

Seventy-one patients were allocated into two groups: I (n = 38 open left pleural cavity and pleural drain inserted in the subxyphoid position); II (n = 33 intact pleural cavity). Pulmonary function tests and clinical parameters were recorded preoperatively and on postoperative days (POD) 1, 3 and 5. Arterial blood gas analysis and shunt fraction were evaluated preoperatively and in POD1. Pain score was assessed on POD1. To monitor pleural effusion and atelectasis chest radiography was performed routinely 1 day before operation and until POD5.

RESULTS

In both groups a significant impairment was found in lung function parameters until on POD5. However, no significant difference in forced vital capacity and forced expiratory volume in 1 second were seen between groups. A significant decrease in partial pressure of arterial oxygen and an increase in shunt fraction values were observed on POD1 in both groups, but no statistical difference was found when the groups were compared. Pleural effusion and atelectasis until on POD5 were similar in both groups. There were no statistical differences in pain score, duration of mechanical ventilation and postoperative hospital stay between groups.

CONCLUSION

Subxyphoid insertion of pleural drain provides similar effects to preserved pleural integrity in pulmonary function, clinical outcomes, and thoracic pain after OPCAB. Therefore, our results support the hypothesis that once pleural cavities are incidentally or purposely opened during LITA dissection, subxyphoid placement of the pleural drain is recommended.

Variáveis hemodinâmicas, hemogasométricas e respiratórias em pacientes cardiopatas submetidos ao teste de respiração espontânea

CONTEXTUALIZAÇÃO: Apesar de existirem situações em que há necessidade da ventilação mecânica (AVM), sua retirada (desmame) deve ocorrer tão breve quanto possível, sendo o teste de respiração espontânea (TRE) uma ferramenta útil para abreviar e reduzir os riscos. Existem diversas formas de realizar o TRE, porém, em pacientes cardiopatas, o mais eficaz parece ser associado à pressão de suporte (PSV) e à pressão positiva no final da expiração (PEEP). OBJETIVO: Analisar, ao início e ao término do TRE no modo PSV, o comportamento das variáveis hemodinâmicas, hemogasométricas e respiratórias em pacientes cardiopatas. MÉTODO: 22 pacientes cardiopatas foram submetidos ao TRE por 30 minutos, dos quais cinco foram excluídos e 17 conseguiram concluir o teste. Para mensuração da força muscular inspiratória e da mecânica respiratória, avaliou-se imediatamente antes do TRE: pressão inspiratória inicial e inspiratória máxima, resistência das vias aéreas, complacência estática e dinâmica seguida da avaliação do volume corrente, frequência respiratória, parâmetros hemodinâmicos e hemogasométricos. Todos os parâmetros foram reavaliados 30 minutos após o TRE. RESULTADOS: Os valores tratados na análise estatística dessas variáveis não apresentaram diferença significativa, apenas o índice de desmame ventilatório mostrou variação significativa (p = 0,011). CONCLUSÃO: Por meio do presente estudo, percebeu-se que a maior parte dos pacientes cardiopatas submetidos ao TRE utilizando PSV manteve-se em estabilidade hemodinâmica, hemogasométrica e respiratória. Além disso, percebeu-se que cerca de 82% obteve sucesso ao desmame, sugerindo que PSV é um método seguro e eficaz na interrupção AVM. Contudo, por causa da amostra reduzida, o desenvolvimento de estudos semelhantes torna-se necessário.

Doppler-defined pulmonary hypertension in medical intensive care unit patients: Retrospective investigation of risk factors and impact on mortality

Pulmonary hypertension (PH) is poorly characterized in the critically ill. No prior studies describe the burden of or outcomes associated with PH in a general medical intensive care unit population. We hypothesize that PH is an important comorbidity prevalent in the modern medical intensive care unit. We undertook a preliminary investigation to define the consequences of Doppler-defined PH in the critically ill. A single-center retrospective case–control study of medical intensive care patients admitted over a 1-year period was conducted. Eligible patients had an echocardiogram within 4 days of admission. PH was defined to include both pulmonary arterial and venous hypertension and required a tricuspid regurgitant jet velocity ≥3 m/sec. Cases and controls were compared for comorbidities, illness severity, diagnoses, and mortality. Multivariable regression was performed to identify clinical features associated with PH and mortality. 299 (21% of admissions) patients had an eligible echocardiogram. Patients with PH (N=126) had a higher unadjusted mortality than did controls (N=173) (37% vs. 25%, P=0.04) and PH remained significantly associated with mortality after controlling for other clinical factors (HR=1.59, 95% CI=1.03–2.44, P=0.036). Low ejection fraction (OR=2.21, 95% CI=1.19–4.11, P=0.012) and pulmonary embolism (OR=4.28, 95% CI=1.59–11.5, P=0.004) were independently associated with PH. Doppler-defined PH is associated with mortality in the critically ill. Prospective studies are needed to define the prevalence of pulmonary venous hypertension versus pulmonary arterial hypertension, and the clinical consequences of each, in a general medical intensive care unit population.

Aspiration Prevention Protocol: Decreasing Postoperative Pneumonia in Heart Surgery Patients

Background

Postoperative pneumonia contributes to morbidity and mortality in patients who have open heart surgery.

Objectives

To determine if measures to reduce aspiration in patients after cardiothoracic surgery would decrease the occurrence of postoperative pneumonia.

Methods

All patients undergoing cardiothoracic surgery from April 2008 through October 2008 were prospectively enrolled in the study. An aspiration prevention protocol was developed and implemented in a 24-bed intensive care unit. The protocol incorporated a bedside swallowing evaluation by a speech therapist and progressive oral intake.

Results

In the 6 months before development and implementation of the protocol, postoperative pneumonia developed in 11% of patients. After implementation of the protocol, no patients had postoperative pneumonia (P &lt; .01).

Conclusions

Implementing an aspiration prevention protocol was effective in reducing the occurrence of postoperative pneumonia in patients who had cardiothoracic surgery.

Using the theory of planned behavior to predict the use of incentive spirometry among cardiac surgery patients in Taiwan

OBJECTIVE

The use of incentive spirometry (IS) is reported to prevent and treat postoperative pulmonary complications. This study sought to use the theory of planned behavior to predict the use of IS in this population.

METHODS

The study used a prospective design, with convenience sampling, to recruit a total of 116 postcardiac-surgery patients from 2 medical centers in Taipei, Taiwan, from November 2008 to May 2009. Data were collected through 2 instruments: a demographic questionnaire, and an IS questionnaire. Descriptive analysis, independent t test, one-way analysis of variance, binary regression, and liner regression were used to analyze the data.

RESULTS

Perceived behavioral control, but not intention, was a predictor of the use of IS.

CONCLUSION

Our findings provide partial support for the utility of the theory of planned behavior in explaining the use of IS behavior for cardiac surgery patients.

[Evaluation of the postoperative acute pain after heart surgery]

INTRODUCTION

Pain is one of the main symptoms reported by patients who have had heart surgery.

OBJECTIVES

To describe the pain and explain the possible association among demographics, psychological and biological variables of the patients subjected to heart surgery with pain intensity during the postoperative in the ICU.

PATIENTS AND METHOD

A descriptive, longitudinal study conducted between February 2008 and January 2009 on patients subjected to heart surgery with admission to the ICU of the Hospital of Navarra was conducted. A preoperatory interview was made with registration of sociodemographic, biological and psychological variables. Pain intensity was monitored during the first 48 hours of ICU stay with the Verbal Numeric Scale (VNS) of pain. Accepted level of significance was p<0.05.

RESULTS

A sample of 69 patients with mean age of 62, 26% women and 74% men was included. A superior statistical association was found between postoperative pain levels for age<65 years, bypass grafting with internal mammary artery and preoperatory anxiety variables. There was a significant increase in analgesic consumption for incomes>1400 €/month, bypass grafting with internal mammary artery and preoperatory anxiety.

CONCLUSIONS

Postoperative pain after heart surgery show significant individual variability. In our study, age, bypass grafting with internal mammary artery and preoperatory anxiety were shown as predictive variables of postoperative pain in patients undergoing heart surgery.

Longitudinal evaluation the pulmonary function of the pre and postoperative periods in the coronary artery bypass graft surgery of patients treated with a physiotherapy protocol

Background

The treatment of coronary artery disease (CAD) seeks to reduce or prevent its complications and decrease morbidity and mortality. For certain subgroups of patients, coronary artery bypass graft surgery (CABG) may accomplish these goals. The objective of this study was to assess the pulmonary function in the CABG postoperative period of patients treated with a physiotherapy protocol.

Methods

Forty-two volunteers with an average age of 63 ± 2 years were included and separated into three groups: healthy volunteers (n = 09), patients with CAD (n = 9) and patients who underwent CABG (n = 20). Patients from the CABG group received preoperative and postoperative evaluations on days 3, 6, 15 and 30. Patients from the CAD group had evaluations on days 1 and 30 of the study, and the healthy volunteers were evaluated on day 1. Pulmonary function was evaluated by measuring forced vital capacity (FVC), maximum expiratory pressure (MEP) and Maximum inspiratory pressure (MIP).

Results

After CABG, there was a significant decrease in pulmonary function (p < 0.05), which was the worst on postoperative day 3 and returned to the preoperative baseline on postoperative day 30.

Conclusion

Pulmonary function decreased after CABG. Pulmonary function was the worst on postoperative day 3 and began to improve on postoperative day 15. Pulmonary function returned to the preoperative baseline on postoperative day 30.

Physiotherapy in the perioperative period

Surgery and general anaesthesia have direct effects on the respiratory system depending on the organ/system involved and modality of delivery, potentially leading to postoperative pulmonary complications that increase hospital morbidity, prolong hospital stay and add to health-care costs. Postoperative complications have been reported to be as high as 30% for thoracotomy and lung resection in patients with chronic obstructive pulmonary disease. Most of the complications are due to respiratory muscle dysfunction and surgery-related changes in chest wall mechanics. In general, preoperative optimisation of medical therapy combined with physiotherapy and early extubation and mobilisation may improve clinical outcomes in high-risk surgeries, including upper abdominal and thoracic surgery in patients with severe emphysema. Evidence from randomised controlled trials or meta-analyses is limited and most of the recommendations on perioperative physiotherapy come from either uncontrolled or non-randomised trials or from observational studies and expert opinion.

The management of acute pulmonary arterial hypertension

Acute pulmonary arterial hypertension (PAH), which may complicate the course of many complex disorders, is always underdiagnosed and its treatment frequently begins only after serious complications have developed. Acute PAH is distinctive because they differ in their clinical presentation, diagnostic findings, and response to treatment from chronic PAH. The acute PAH may take either the form of acute onset of chronic PAH or acute PAH or surgery-related PAH. Significant pathophysiologic differences existed between acute and chronic PAH. Therapy of acute PAH should generally be aimed at acutely relieving right ventricular (RV) pressure overload and preventing RV dysfunction. There are three classes of drugs targeting the correction of abnormalities in endothelial dysfunction, which have been approved recently for the treatment of PAH: (1) prostanoids; (2) endothelin receptor antagonists; and (3) phosphodiesterase-5 inhibitors. The efficacy and safety of these compounds have been confirmed in uncontrolled studies in patients with PAH. Intravenous epoprostenol is suggested to serve as the first-line treatment for the most severe patients. In the other situations, the first-line therapy may include bosentan, sildenafil, or a prostacyclin analogue. Recent advances in the management of PAH have markedly improved prognosis.

Influência da força muscular respiratória pré-operatória na evolução clínica após cirurgia de revascularização do miocárdio

O objetivo foi avaliar se diferenças na força muscular respiratória pré-operatória: a) se relacionam com outros fatores de risco pré-operatórios; e b) influenciam o risco de surgimento de complicações pulmonares pós-operatórias (CPP), os tempos de permanência em ventilação mecânica (VM) e em unidade de terapia intensiva (UTI) e hospitalar após cirurgia de revascularização do miocárdio. O estudo foi observacional, prospectivo, tipo coorte. Vinte e quatro indivíduos concluíram o estudo e, após análise dos valores da manovacuometria pré-operatória, foram alocados em: G1, com pressão inspiratória máxima (PImáx) >70% do previsto (n=13, 54%); e G2, PImáx <70% do previsto (n=11, 46%). Na análise estatística adotou-se o nível de significância de 5% (p<0,05); também foi calculado o risco relativo (RR). Os grupos foram homogêneos (p>0,05) quanto à maioria das variáveis obtidas no pré-operatório (exceto PImáx e PEmáx) e aos dados cirúrgicos. Quase metade dos pacientes do G2, com PImáx inferior, também apresentaram pressão expiratória máxima (PEmáx) inferior à prevista. Os tempos de VM, de internação em UTI e hospitalar pós-operatória, e a presença de CPP não diferiram estatisticamente entre os grupos. Quando comparados aos do G1, os indivíduos do grupo que apresentava fraqueza muscular respiratória (G2) antes da cirurgia revelaram maior risco relativo para o desenvolvimento de complicações pulmonares pós-operatórias.

Incentive spirometry with expiratory positive airway pressure reduces pulmonary complications, improves pulmonary function and 6-minute walk distance in patients undergoing coronary artery bypass graft surgery

BACKGROUND

The use of the incentive spirometry (IS) with expiratory positive airway pressure (EPAP) to prevent postoperative pulmonary complications (PPC) after coronary artery bypass graft (CABG) is not well established. This study sought to determine the effects of IS+EPAP after CABG.

METHODS

Thirty-four patients undergoing CABG were randomly assigned to a control group or IS+EPAP group. Maximal respiratory pressures, pulmonary function test, 6-minute walk test and chest x-ray were performed at baseline as well as 1 week and 1 month after CABG.

RESULTS

Maximal inspiratory pressure was significantly higher in the IS+EPAP group compared to controls at both 1 week and 1 month (P<.001). Maximal expiratory pressure was significantly higher at 1 month compared to 1 week in IS+EPAP group (P<.01). At 1 month, forced vital capacity and forced expiratory volume in 1 second was significantly higher in IS+EPAP compared to controls (P<.05). Inspiratory capacity was higher at 1 month in IS+EPAP group compared to controls (P<.05). The distance walked in 6-minute walk test was higher at 1 month in IS+EPAP group (P<.001) compared to controls. Lastly, radiological injury score at 1 week was lower in IS+EPAP compared to controls (P<.004).

CONCLUSIONS

In patients undergoing CABG, IS+EPAP results in improved pulmonary function and 6-minute walk distance as well as a reduction in PPC.

The incidence and cost of cardiac surgery adverse events in Australian (Victorian) hospitals 2003-2004

The aim of this study was to estimate the incidence of adverse events in acute surgical admissions for cardiac disease in admitted episodes in the year 2003-2004 and to estimate the cost of these complications to the Victorian health system. Cardiac surgery adverse events are among the most frequent and significant contributors to the morbidity, mortality and cost associated with hospitalisation. Patient-level costing data set for major Victorian public hospitals in 2003-2004 was analysed for adverse events using C-prefixed markers, denoting complications that arose during the course of hospital treatment for cardiac surgery diagnosis related groups (DRGs). The cost of adverse events was estimated by linear regression modelling, adjusted for age and co-morbidity. A total of 16,766 multi-day cardiac disease cases were identified, of whom 6,181 (36.85%) had at least one adverse event. Patients with adverse events stayed approximately 7 days longer and had four times the case fatality rate than those without. After adjustment for age and co-morbidity, the presence of an adverse event adds AUS$5,751. The sum of the total cost of adverse events for each DRG was AUS$42.855 million, representing 21.6% of total expenditure on cardiac surgery and adding 27.5% in broad terms to the cardiac surgery budget.

Influence of pleurotomy on pulmonary function after off-pump coronary artery bypass grafting

BACKGROUND

This study evaluated the influence of pleurotomy on pulmonary function after off-pump coronary artery bypass grafting (CABG) using the left internal thoracic artery (LITA).

METHODS

Thirty patients were prospectively allocated into two groups: 15 patients with an opened left pleural cavity (OP group) and 15 patients with an intact pleural cavity (IP group). Bedside pulmonary function tests were recorded preoperatively and on postoperative days 1, 3, and 5. Arterial blood gas analyses and ratio of partial pressure of arterial oxygen (PaO2/fraction of inspired oxygen (FiO2) ratio were evaluated preoperatively and on postoperative day 1.

RESULTS

A significant decrease of pulmonary function was observed in both groups until postoperative day 5. When compared with the percentage of the preoperative value, the forced vital capacity was significantly lower in the OP group than in the IP group on postoperative days 1 (33.3% +/- 8.3% versus 49.1% +/- 8.4%, p < 0.001), 3 (45.4% +/- 7.0% versus 62.1% +/- 8.6%, p < 0.001), and 5 (56.1% +/- 8.7% versus 77.5% +/- 11.6%, p < 0.001). Similar results were found for forced expiratory volume in 1 second on postoperative days 1 (35.7% +/- 8.6% versus 50.0% +/- 9.8%, p < 0.001), 3 (48.4% +/- 7.0% versus 61.5% +/- 9.02%, p < 0.001) and 5 (58.8% +/- 8.5% versus 75.9% +/- 10.2%, p < 0.001). The PaO2 value and the PaO2/FiO2 ratio dropped on postoperative day 1 in both groups (p < 0.05), with a higher fall in the OP group (p < 0.05). Orotracheal intubation time (p = 0.012) and hospital stay (p = 0.002) were lower in the IP group.

CONCLUSIONS

Off-pump CABG using the LITA, independently of pleural opening, induced a significant reduction in early postoperative pulmonary function. However, the patients undergoing pleurotomy demonstrated more pronounced pulmonary dysfunction.

Mechanical Ventilation for Cardiac Support

Postoperative lung injury is a common, although decreasing, complication of cardiac surgery. This article discusses various means to prevent and minimize postoperative lung injury. These include lung-protective strategies, pharmacologic strategies, and mechanical ventilation.

Frequency and Predictors of Return to Incentive Spirometry Volume Baseline After Cardiac Surgery

Incentive spirometry (IS) is routinely used in most clinical settings, but evaluation of patient efficacy of IS is not standardized. The purpose of this study was to describe the degree and predictors of return to preoperative IS volume after cardiac surgery. IS volumes were documented in 69 subjects (71% men; mean age, 59 years) undergoing cardiac surgery during the preoperative evaluation and twice daily postoperatively. Nineteen percent of subjects achieved their IS preoperative volume by hospital discharge. Based on highest volume achieved, subjects achieved an average of 75% of their preoperative volume by discharge, and only age and number of bypass grafts predicted return to preoperative IS volume. These data may assist nurses and patients to set realistic goals for postoperative IS volume achievement.