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

Effect of Buteyko Breathing Technique as an Adjunct to Routine Physiotherapy on Pulmonary Functions in Patients Undergoing Off-pump Coronary Artery Bypass Surgery: A Randomized Controlled Trial

Background

Coronary artery disease (CAD) poses a substantial and increasing public health concern in India, particularly among individuals aged 20 and above. The postoperative phase following coronary artery bypass graft (CABG) surgery presents potential complications, notably impacting the pulmonary system. Emerging evidence suggests that the Buteyko breathing technique not only improves lung function but also positively influences the psychological well-being of CABG patients. This study seeks to assess the impact of the Buteyko breathing technique on pulmonary functions in individuals who have undergone off-pump CABG.

Materials and methods

In this randomized controlled trial, patients undergoing off-pump CABG were allocated to either the Buteyko breathing technique group (n = 35) or the control group (n = 35). The intervention group received supervised Buteyko breathing technique sessions twice daily for 15 minutes, concurrently with cardiac rehabilitation from postoperative day (POD-2 to POD-7). The control group underwent phase I cardiac rehabilitation. Outcome measures, including pulmonary function test (PFT), chest expansion, and breath-holding tests were evaluated at baseline (POD-2) and conclusion (POD-7).

Results

Statistical analyses were conducted with a significance level set at p < 0.05. Both the control and intervention groups exhibited statistically significant improvements in pulmonary function, chest expansion at three levels, and breath-holding time (p = 0.0001). However, the Buteyko breathing group demonstrated a more significant improvement compared with the control group.

Conclusion

The integration of the Buteyko breathing technique into conventional physiotherapy proves to be a beneficial strategy, leading to improvements in pulmonary function, breath-holding duration, and chest expansion for individuals who underwent off-pump CABG surgery.

How to cite this article

Mavkar SS, Shukla MP. Effect of Buteyko Breathing Technique as an Adjunct to Routine Physiotherapy on Pulmonary Functions in Patients Undergoing Off-pump Coronary Artery Bypass Surgery: A Randomized Controlled Trial. Indian J Crit Care Med 2024;28(3):280-285.TRI Number: CTRI/2022/12/048295.

Identifying High-Risk Patients for Severe Pulmonary Complications after Cardiosurgical Procedures as a Target Group for Further Assessment of Lung-Protective Strategies

OBJECTIVES

It remains unclear whether intraoperative lung-protective strategies can reduce the rate of respiratory complications after cardiac surgery, partly because low-risk patients have been studied in the past. The authors established a screening model to easily identify a high-risk group for severe pulmonary complications (ie, pneumonia or acute respiratory distress syndrome) that may be the ideal target population for the assessment of the potential benefits of such measures.

DESIGN

Retrospective observational trial.

SETTING

Departments of cardiac surgery and cardiac anesthesia of a university hospital.

PARTICIPANTS

Consecutive patients undergoing cardiac surgery on cardiopulmonary bypass and subsequent treatment at a dedicated cardiosurgical intensive care unit between January 2019 and March 2021.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of the 2,572 patients undergoing surgery, 84 (3.3%) developed pneumonia/acute respiratory distress syndrome that significantly affected the outcome (ie, longer ventilatory support [66% vs 11%], higher reintubation rate [39% vs 3%]), prolonged length of intensive care unit [33 ± 36 vs 4 ± 10 days] and hospital stay [10 ± 15 vs 6 ± 7 days], and higher in-hospital [43% vs 9%] as well as 30-day [7% vs 3%] mortality). The screening model for severe pulmonary complications included left ventricular ejection fraction <52%, EuroSCORE II (European System for Cardiac Operative Risk Evaluation II) >5.9, cardiopulmonary bypass time >123 minutes, left ventricular assist device or aortic repair surgery, and bronchodilatory therapy. A cutoff for the predicted risk of 2.5% showed optimal sensitivity and specificity, with an area under the receiver operating characteristic curve of 0.82.

CONCLUSIONS

The authors suggest that future research on intraoperative lung-protective measures focuses on this high-risk population, primarily aiming to mitigate severe forms of postoperative pulmonary dysfunction associated with poor outcomes and increased resource consumption.

The impact of cardiopulmonary rehabilitation in phase II cardiac rehabilitation program on the health-related quality of life of patients undergoing coronary artery bypass graft surgery

BACKGROUND

Coronary artery bypass surgery is the leading cause of change in the quality of life and pulmonary function of patients. One strategy to enhance lung muscle strength and improve overall quality of life is pulmonary rehabilitation. This study aimed to investigate the impact of incorporating a pulmonary rehabilitation program into phase II cardiac rehabilitation program on the quality of life of patients undergoing coronary artery bypass graft surgery.

METHODS

This randomized clinical trial study included 53 patients who underwent coronary artery bypass graft surgery at Imam Reza Hospital in Mashhad between September 2019 and March 2020. The research participants were selected based on specific inclusion criteria and divided into two groups. The control group followed the routine rehabilitation program, whereas the intervention group underwent a pulmonary rehabilitation program for 20-30 min after each session of the cardiac rehabilitation program. Data collection tools included a demographic information questionnaire and the Ferrans and Powers' quality of life index. The data were analyzed using the independent t-test, Mann-Whitney test, paired t-test, Spearman correlation, Wilcoxon test, and SPSS25.

RESULTS

The mean quality of life score in the intervention group(20.7±1.8) was significantly higher than that of the control group (18.8±2.3)(P < 0.05). Furthermore, the intervention group exhibited significantly higher mean scores in the physical, psychological-spiritual, and family dimensions than the control group(P < 0.05).

CONCLUSION

The study results demonstrate the positive impact of incorporating a pulmonary rehabilitation program into cardiac rehabilitation on the health-related quality of life of patients undergoing coronary artery bypass graft surgery.

TRIAL REGISTRATION

IRCT20190707044132N1.

Neural respiratory drive assessment and its correlation with inspiratory muscle strength in patients undergoing open-heart surgery: A cross-sectional study

BACKGROUND AND PURPOSE

Pulmonary dysfunction and inspiratory muscle weakness are frequently observed after cardiac surgery. Understanding the load on and capacity of respiratory muscles can provide valuable insights into the overall respiratory mechanics and neural regulation of breathing. This study aimed to assess the extent of neural respiratory drive (NRD) and determine whether admission-to-discharge differences in NRD were associated with inspiratory muscle strength changes among patients undergoing open-heart surgery.

METHODS

This cross-sectional study was conducted on 45 patients scheduled for coronary artery bypass graft or heart valve surgery. NRD was measured using a surface parasternal intercostal electromyogram during resting breathing (sEMGpara tidal) and maximal inspiratory effort (sEMGpara max). Maximal inspiratory pressure (MIP) was used to determine inspiratory muscle strength. Evaluations were performed on the day of admission and discharge.

RESULTS

There was a significant increase in sEMGpara tidal (6.9 ± 3.6 μV, p < 0.001), sEMGpara %max (13.7 ± 11.2%, p = 0.008), and neural respiratory drive index (NRDI, the product of EMGpara %max and respiratory rate) (337.7 ± 286.8%.breaths/min, p < 0.001), while sEMGpara max (-43.6 ± 20.4 μV, p < 0.01) and MIP (-24.4 ± 10.7, p < 0.001) significantly decreased during the discharge period. Differences in sEMGpara tidal (r = -0.369, p = 0.045), sEMGpara %max (r = -0.646, p = 0.001), and NRDI (r = -0.639, p = 0.001) were significantly associated with a reduction in MIP.

DISCUSSION

The findings indicate that NRD increases after open-heart surgery, which corresponds to a decrease in inspiratory muscle strength.

Preoperative respiratory muscle training reduces the risk of pulmonary complications and the length of hospital stay after cardiac surgery: a systematic review

QUESTIONS

What is the effect of preoperative respiratory muscle training (RMT) on the incidence of postoperative pulmonary complications (PPCs) after open cardiac surgery? What is the effect of RMT on the duration of mechanical ventilation, postoperative length of stay and respiratory muscle strength?

DESIGN

Systematic review of randomised trials with meta-analysis.

PARTICIPANTS

Adults undergoing elective open cardiac surgery.

INTERVENTION

The experimental groups received preoperative RMT and the comparison groups received no intervention.

OUTCOME MEASURES

The primary outcomes were PPCs, length of hospital stay, respiratory muscle strength, oxygenation and duration of mechanical ventilation. The methodological quality of studies was assessed using the PEDro scale and the overall certainty of the evidence was assessed using the GRADE approach.

RESULTS

Eight trials involving 696 participants were included. Compared with the control group, the respiratory training group had fewer PPCs (RR 0.51, 95% CI 0.38 to 0.70), less pneumonia (RR 0.44, 95% CI 0.25 to 0.78), shorter hospital stay (MD -1.7 days, 95% CI -2.4 to -1.1) and higher maximal inspiratory pressure values at the end of the training protocol (MD 12 cmH2O, 95% CI 8 to 16). The mechanical ventilation time was similar in both groups. The quality of evidence was high for pneumonia, length of hospital stay and maximal inspiratory pressure.

CONCLUSION

Preoperative RMT reduced the risk of PPCs and pneumonia after cardiac surgery. The training also improved the maximal inspiratory pressure and reduced hospital stay. The effects on PPCs were large enough to warrant use of RMT in this population.

REGISTRATION

CRD42021227779.

Capnodynamic monitoring of lung volume and pulmonary blood flow during alveolar recruitment: a prospective observational study in postoperative cardiac patients

Alveolar recruitment manoeuvres may mitigate ventilation and perfusion mismatch after cardiac surgery. Monitoring the efficacy of recruitment manoeuvres should provide concurrent information on pulmonary and cardiac changes. This study in postoperative cardiac patients applied capnodynamic monitoring of changes in end-expiratory lung volume and effective pulmonary blood flow. Alveolar recruitment was performed by incremental increases in positive end-expiratory pressure (PEEP) to a maximum of 15 cmH2O from a baseline of 5 cmH2O over 30 min. The change in systemic oxygen delivery index after the recruitment manoeuvre was used to identify responders (> 10% increase) with all other changes (≤ 10%) denoting non-responders. Mixed factor ANOVA using Bonferroni correction for multiple comparisons was used to denote significant changes (p < 0.05) reported as mean differences and 95% CI. Changes in end-expiratory lung volume and effective pulmonary blood flow were correlated using Pearson's regression. Twenty-seven (42%) of 64 patients were responders increasing oxygen delivery index by 172 (95% CI 61-2984) mL min-1 m-2 (p < 0.001). End-expiratory lung volume increased by 549 (95% CI 220-1116) mL (p = 0.042) in responders associated with an increase in effective pulmonary blood flow of 1140 (95% CI 435-2146) mL min-1 (p = 0.012) compared to non-responders. A positive correlation (r = 0.79, 95% CI 0.5-0.90, p < 0.001) between increased end-expiratory lung volume and effective pulmonary blood flow was only observed in responders. Changes in oxygen delivery index after lung recruitment were correlated to changes in end-expiratory lung volume (r = 0.39, 95% CI 0.16-0.59, p = 0.002) and effective pulmonary blood flow (r = 0.60, 95% CI 0.41-0.74, p < 0.001). Capnodynamic monitoring of end-expiratory lung volume and effective pulmonary blood flow early in postoperative cardiac patients identified a characteristic parallel increase in both lung volume and perfusion after the recruitment manoeuvre in patients with a significant increase in oxygen delivery.Trial registration This study was registered on ClinicalTrials.gov (NCT05082168, 18th of October 2021).

Three Logistic Predictive Models for the Prediction of Mortality and Major Pulmonary Complications after Cardiac Surgery

Background and Objectives: Pulmonary complications are a leading cause of morbidity after cardiac surgery. The aim of this study was to develop models to predict postoperative lung dysfunction and mortality. Materials and Methods: This was a single-center, observational, retrospective study. We retrospectively analyzed the data of 11,285 adult patients who underwent all types of cardiac surgery from 2003 to 2015. We developed logistic predictive models for in-hospital mortality, postoperative pulmonary complications occurring in the intensive care unit, and postoperative non-invasive mechanical ventilation when clinically indicated. Results: In the "preoperative model" predictors for mortality were advanced age (p < 0.001), New York Heart Association (NYHA) class (p < 0.001) and emergent surgery (p = 0.036); predictors for non-invasive mechanical ventilation were advanced age (p < 0.001), low ejection fraction (p = 0.023), higher body mass index (p < 0.001) and preoperative renal failure (p = 0.043); predictors for postoperative pulmonary complications were preoperative chronic obstructive pulmonary disease (p = 0.007), preoperative kidney injury (p < 0.001) and NYHA class (p = 0.033). In the "surgery model" predictors for mortality were intraoperative inotropes (p = 0.003) and intraoperative intra-aortic balloon pump (p < 0.001), which also predicted the incidence of postoperative pulmonary complications. There were no specific variables in the surgery model predicting the use of non-invasive mechanical ventilation. In the "intensive care unit model", predictors for mortality were postoperative kidney injury (p < 0.001), tracheostomy (p < 0.001), inotropes (p = 0.029) and PaO2/FiO2 ratio at discharge (p = 0.028); predictors for non-invasive mechanical ventilation were kidney injury (p < 0.001), inotropes (p < 0.001), blood transfusions (p < 0.001) and PaO2/FiO2 ratio at the discharge (p < 0.001). Conclusions: In this retrospective study, we identified the preoperative, intraoperative and postoperative characteristics associated with mortality and complications following cardiac surgery.

The effect of Preoperative threshold inspiratory muscle training in adults undergoing cardiac surgery on postoperative hospital stay: a systematic review

BACKGROUND

Systematic reviews have reported benefits of preoperative inspiratory muscle training in adults undergoing cardiac surgery, however there have been inconsistencies with the devices used. Threshold devices generate a constant inspiratory load independent of respiratory rate.

OBJECTIVE

To assess the effect of preoperative inspiratory muscle training using threshold devices in adults undergoing cardiac surgery.

METHODS

A literature search was conducted across five electronic databases. Seven randomized controlled trials met the inclusion criteria and were critically appraised. The primary outcome was length of hospital stay. Secondary outcomes included postoperative pulmonary complications, quality of life and mortality.

RESULTS

Seven eligible randomized controlled trials were identified with a total of 642 participants. One study was a post hoc analysis of one of the included studies. Three out of five studies reported a decrease in length of postoperative hospital stay (p < 0.05). A significant reduction in postoperative pulmonary complications was reported by three studies (p < 0.05). There were concerns with bias across all papers.

CONCLUSIONS

Preoperative threshold inspiratory muscle training has potential to reduce postoperative length of hospital stay and pulmonary complications after cardiac surgery. The evidence on quality of life and mortality is inconclusive. The overall evidence for these conclusions may be influenced by bias.

Effectiveness of Acapella along with institutional based chest physiotherapy techniques on pulmonary functions and airway clearance in post-operative CABG patients

BACKGROUND

Patients undergoing Coronary Artery Bypass Graft (CABG) surgery often develop pulmonary complications in the early post-operative period as result of decreased lung function and impaired cough. Conventional physiotherapy in early post-operative period aims at increasing lung volumes and airway clearance.

OBJECTIVE

This study aimed to determine the effectiveness of the addition of Acapella to conventional chest physiotherapy in improving lung volumes and secretion clearance in early post-operative CABG patients.

METHODS

Twenty patients of both genders (40-70 years) who had undergone CABG and were in Phase I of Cardiac Rehabilitation were involved in this pilot randomized control trial (9 control, 11 experimental). Post-surgery intervention commenced on post-operative day 2 (POD 2) and continued till POD 6. Patients in the control group were given conventional physiotherapy that included breathing exercises, incentive spirometry and manual techniques. Patient in the experimental group used an Acapella device along with the conventional intervention. Outcome measures considered were pulmonary function parameters (FVC, FEV1 & PEFR) and amount of sputum expectorated.

RESULTS

A significant increase in lung volumes was observed in both the groups on POD 6 as compared to POD 2 (both < 0 . 01 ). However, the increase was significantly greater on POD 6 in experimental group than the control group [mean difference (95% CI) FVC: 0.44 L (0.24-0.63), FEV1: 0.43 L (0.19-0.66), PEFR: 0.86 L/s (0.57-1.14)]. The amount of sputum expectoration significantly greater in the experimental group as compared to the control group [2.71 mL (0.53-4.90)].

CONCLUSION

The addition of Acapella enhanced the effect conventional physiotherapy in improving lung volumes and airway clearance in the early post-operative period for CABG patients.

Factors influencing the use of postoperative bilevel positive airway pressure (BiPAP) in patients undergoing adult cardiac surgery: A retrospective cohort study

BAckground and Aims

Respiratory complications are one of the biggest challenges following cardiac surgery, which can lead to hypoxia and acute respiratory failure (ARF). The aim of this study to identify the factors led to BiPAP application for postoperative respiratory complications and its effectiveness as the main outcome measures after cardiac surgery.

Methods

It was a retrospective cohort study with consecutive sampling technique. A total of 335 postcardiac surgery patients medical record was reviewed who were underwent for surgery from November 1, 2018 to November 30, 2019. 265 patients were finalized for the recruitment, five patients were excluded before the final analysis. Data of 260 patients were analyzed for compiling of results.

Results

The mean age was 59 years. 196 (75.4%) patients were males and females were 64 (24.6%). Mean weight was 72 kg and mean body mass index (BMI) 26.67 kg/m²_. BiPAP application was in 38 (14.6%) patients and significantly high in with high BMI, (p < 0.05). There are significant associations of BiPAP application patients with COPD (p < 0.05). Patients with positive fluid balance, cardiac dysfunction, and required inotropic support were significantly associated with BiPAP need (p < 0.05), respectively.

Conclusion

BiPAP is effective to treat ARF and other respiratory complications after adult cardiac surgeries. High BMI, atelectasis, and pneumonia are also the independent factors causing ARF. BiPAP can be a successful tool for preventing the adverse effects of postoperative pulmonary complications after cardiac surgery.

Post-cardiopulmonary bypass hypoxaemia in paediatric patients undergoing congenital heart disease surgery: risk factors, features, and postoperative pulmonary complications

Background

Hypoxemia after cardiopulmonary bypass (CPB) is the quantifiable manifestation of pulmonary dysfunction. This retrospective study was designed to investigate the risk factors for post-cardiopulmonary bypass hypoxaemia and the features of hypoxaemia and pulmonary complications in paediatric congenital heart disease surgery involving CPB.

Methods

Data including demographics, preoperative pulmonary or cardiac parameters, and intraoperative interventions were retrospectively collected from 318 paediatric patients who underwent radical surgery with CPB for congenital heart disease. Among them, the factors that were significant by univariate analysis were screened for multivariate Cox regression. The lowest ratio of arterial oxygen tension and the inspiratory oxygen fraction (PaO₂/FiO₂), hypoxaemia (PaO₂/FiO₂ ≤ 300) insult time, duration of hypoxaemia, extubation time, and pulmonary complications were also analysed postoperatively.

Results

The morbidity of post-cardiopulmonary bypass hypoxaemia was 48.4% (154/318). Months (6 < months ≤ 12, 12 < months ≤ 36 and 36 < months compared with 0 ≤ months ≤ 6: HR 0.582, 95% CI 0.388–0.873; HR 0.398, 95% CI 0.251–0.632; HR 0.336, 95% CI 0.197–0.574, respectively; p < 0.01), preoperative intracardiac right-to-left shunting (HR 1.729, 95% CI 1.200–2.493, p = 0.003) and intraoperative pleural cavity entry (HR 1.582, 95% CI 1.128–2.219, p = 0.008) were identified as independent risk factors for the development of post-cardiopulmonary bypass hypoxaemia. Most hypoxaemia cases (83.8%, 129/154) occurred within 2 h, and the rate of moderate hypoxaemia (100 < PaO₂/FiO₂ ≤ 200) was 60.4% (93/154).

Conclusion

The morbidity of post-cardiopulmonary bypass hypoxaemia in paediatric congenital heart disease surgery was considerably high. Most hypoxaemia cases were moderate and occurred in the early period after CPB. Scrupulous management should be employed for younger infants or children with preoperative intracardiac right-to-left shunting or intraoperative pleural cavity entry.

Efficacy of Early and Enhanced Respiratory Physiotherapy and Mobilization after On-Pump Cardiac Surgery: A Prospective Randomized Controlled Trial

Background: This randomized controlled trial aimed to investigate the influence of physical activity and respiratory physiotherapy on zero postoperative day on clinical, hemodynamic and respiratory parameters of patients undergoing cardiac surgeries under extracorporeal circulation. Methods: 78 patients undergoing coronary artery bypass graft (CABG) or/and valvular heart disease surgeries were randomly assigned into an early and enhanced physiotherapy care group (EEPC group; n = 39) and a conventional physiotherapy care group (CPC group; n = 39). Treatment protocol for the EEPC group included ≤3 Mets of physical activity and respiratory physiotherapy on zero post-operative day and an extra physiotherapy session during the first three post-operative days, whereas the CPC group was treated with usual physiotherapy care after the first post-operative day. The length of hospital and intensive care unit (ICU) stay were set as the primary study outcomes, while pre- and post-intervention measurements were also performed to assess the oxymetric and hemodynamic influence of early mobilization and physiotherapy. Results: Participants’ mean age was 51.9 ± 13.8 years. Of them 48 (61.5%) underwent CABG. Baseline and peri-procedural characteristics did not differ between the two groups. The total duration of hospital and ICU stay were significantly higher in the CPC group compared to the EEPC group (8.1 ± 0.4 days versus 8.9 ± 0.6 days and 25.4 ± 3 h versus 23.2 ± 0.6 h, p < 0.001, respectively). Statistically significant differences in pre-intervention oxygen saturation, and post-intervention PO2 and lactate levels were also observed between the two groups (p = 0.022, 0.027 and 0.001, respectively). Conclusion: In on-pump cardiac surgery, early and enhanced post-procedural physical activity (≤3 METS) can prevent a prolonged ICU stay and decrease the duration of hospitalization while ameliorating post-operative hemodynamic and oxymetric parameters.

Prehabilitation as an important stage before cardiac surgery

The review discusses the preparation of patients for surgery on the heart and other organs. We considered the importance of introducing a new stage of medical and cardiology rehabilitation — prehabilitation. The results of randomized clinical trials, systematic reviews and metaanalyzes evaluating the effectiveness of respiratory techniques and physical training during the prehabilitation are presented. Particular attention is paid to the involvement of patients in prehabilitation programs before the elective coronary artery bypass grafting. Methodological problems arising in the development of prehabilitation programs are discussed.

Multidisciplinary, early mobility approach to enhance functional independence in patients admitted to a cardiothoracic intensive care unit: a quality improvement programme

Early mobilisation following cardiac surgery is vital for improved patient outcomes, as it has a positive effect on a patient's physical and psychological recovery following surgery. We observed that patients admitted to the cardiothoracic intensive care unit (CTICU) following cardiac surgery had only bed exercises and were confined to bed until the chest tubes were removed, which may have delayed patients achieving functional independence. Therefore, the CTICU team implemented a quality improvement (QI) project aimed at the early mobilisation of patients after cardiac surgery.A retrospective analysis was undertaken to define the current mobilisation practices in the CTICU. The multidisciplinary team identified various practice gaps and tested several changes that led to the implementation of a successful early mobility programme. The tests were carried out and reported using rapid cycle changes. A model for improvement methodology was used to run the project. The outcomes of the project were analysed using standard 'run chart rules' to detect changes in outcomes over time and Welch's t-test to assess the significance of these outcomes.This project was implemented in 2015. Patient compliance with early activity and mobilisation gradually reached 95% in 2016 and was sustained over the next 3 years. After the programme was implemented, the mean hours required for initiating out-of-bed-mobilisation was reduced from 22.77 hours to 11.74 hours. Similarly, functional independence measures and intensive care unit mobility scores also showed a statistically significant (p<0.005) improvement in patient transfers out of the CTICU.Implementing an early mobility programme for post-cardiac surgery patients is both safe and feasible. This QI project allowed for early activity and mobilisation, a substantial reduction in the number of hours required for initiating out-of-bed mobilisation following cardiac surgery, and facilitated the achievement of early ambulation and functional milestones in our patients.

Effectiveness of Inspiratory Muscle Training on Respiratory Muscle Strength in Patients Undergoing Cardiac Surgeries: A Systematic Review With Meta-Analysis

To determine the effect of inspiratory muscle training (IMT) on pulmonary function, respiratory muscle strength (RMS), and functional capacity in patients undergoing cardiac surgery. The PubMed, PEDro, CINAHL, Web of Science, CENTRAL, and EMBASE databases were searched from inception to June 2020. Randomized controlled trials (RCTs) that evaluated patients who underwent cardiac surgery were included in this review. Meta-analysis performed using a random-effects model showed that the mean difference in forced vital capacity, forced expiratory volume in 1 second, 6-minute walk distance, and RMS was 3.47% (95% confidence interval [CI], 0.57 to 6.36), 5.80% (95% CI, 2.03 to 9.56), 78.05 m (95% CI, 60.92 to 95.18), and 4.8 cmH2O (95% CI, -4.00 to 13.4), respectively. There is strong evidence that IMT improves inspiratory muscle strength, pulmonary function, and functional capacity, and reduces the length of hospital stay in patients undergoing cardiac surgery.

Preoperative incentive spirometry for preventing postoperative pulmonary complications in patients undergoing coronary artery bypass graft surgery: a prospective, randomized controlled trial

BACKGROUND

Postoperative pulmonary complications (PPCs) often occur after cardiac operations and are a leading cause of morbidity, inhibit oxygenation, and increase hospital length of stay and mortality. Although clinical evidence for PPCs prevention is often unclear and crucial, measures occur to reduce PPCs. One device usually used for this reason is incentive spirometry (IS). The aim of the study is to evaluate the effect of preoperative incentive spirometry to prevent postoperative pulmonary complications, improve postoperative oxygenation, and decrease hospital stay following coronary artery bypass graft (CABG) surgery patients.

METHODS

This was a clinical randomized prospective study. A total of 80 patients were selected as candidates for CABG at An-Najah National University Hospital, Nablus-Palestine. Patients had been randomly assigned into two groups: incentive spirometry group (IS), SI performed before surgery (study group) and control group, preoperative spirometry was not performed. The 40 patients in each group received the same protocol of anesthesia and ventilation in the operating room.

RESULT

The study findings showed a significant difference between the IS and control groups in the incidence of postoperative atelectasis. There were 8 patients (20.0%) in IS group and 17 patients (42.5%) in the control group (p = 0.03). Mechanical ventilation duration was significantly less in IS group. The median was four hours versus six hours in the control group (p < 0.001). Hospital length of stay was significantly less in IS group, and the median was six days versus seven days in the control group (p < 0.001). The median of the amount of arterial blood oxygen and oxygen saturation was significantly improved in the IS group (p < 0.005).

CONCLUSION

Preoperative incentive spirometry for two days along with the exercise of deep breathing, encouraged coughing, and early ambulation following CABG are in connection with prevention and decreased incidence of atelectasis, hospital stay, mechanical ventilation duration and improved postoperative oxygenation with better pain control. A difference that can be considered both significant and clinically relevant. Trial registration Thai Clinical Trials Registry: TCTR20201020005. Registered 17 October 2020-retrospectively registered.

Perioperative outcomes of combined heart surgery and lung tumor resection: a systematic review and meta-analysis

Objective

The prevalence of patients with concomitant heart and lung lesions requiring surgical intervention is increasing. Simultaneous cardiac surgery and pulmonary resection avoids the need for a second operation. However, there are concerns regarding the potentially increased mortality and complication rates of simultaneous surgery and the adequacy of lung exposure during heart surgery. Therefore, we performed a meta-analysis to evaluate the perioperative mortality and complication rates of combined heart surgery and lung tumor resection.

Methods

A comprehensive literature search was performed in July 2020. The PubMed, Embase, and Web of Science databases were searched to identify studies that reported the perioperative outcomes of combined heart surgery and lung tumor resection. Two reviewers independently screened the studies, extracted data, and assessed the risk of bias of included studies. Pooled proportions and 95% confidence intervals (95% CI) were calculated by R version 3.6.1 using the meta package.

Results

A total of 536 patients from 29 studies were included. Overall, the pooled proportion of operative mortality was 0.01 (95% CI: 0.00, 0.03) and the pooled proportion of postoperative complications was 0.40 (95% CI: 0.24, 0.57) for patients who underwent combined cardiothoracic surgery. Subgroup analysis by lung pathology revealed that, for patients with lung cancer, the pooled proportion of anatomical lung resection was 0.99 (95% CI: 0.95, 1.00) and the pooled proportion of systematic lymph node dissection or sampling was 1.00 (95% CI: 1.00, 1.00). Subgroup analysis by heart surgery procedure found that the pooled proportion of postoperative complications of patients who underwent coronary artery bypass grafting (CABG) patients using the off-pump method was 0.17 (95% CI: 0.01, 0.43), while the pooled proportion of complications after CABG using the on-pump method was 0.61 (95% CI: 0.38, 0.82).

Conclusion

Combined heart surgery and lung tumor resection had a low mortality rate and an acceptable complication rate. Subgroup analyses revealed that most patients with lung cancer underwent uncompromised anatomical resection and mediastinal lymph node sampling or dissection during combined cardiothoracic surgery, and showed off-pump CABG may reduce the complication rate compared with on-pump CABG. Further researches are still needed to verify these findings.

Contrasting effects of three breathing techniques on pulmonary function, functional capacity and daily life functional tasks in patients following valve replacement surgery- A pilot randomized clinical trial

Background

Valve replacement surgeries affect the physiological mechanisms of patients leading to various postoperative pulmonary complications. Lung expansion therapy consisting of numerous techniques is routinely used for the prevention and treatment of these complications.

Objectives

Our study aimed to compare the effects of diaphragmatic breathing (DB), flow (FS) and volume-oriented incentive spirometer (VS) in patients following valve replacement surgery.

Methods

29 patients posted valve replacement surgeries were randomly assigned to VS, FS and DB groups. Patients underwent preoperative training and seven-day rehabilitation post-surgery. Pulmonary function tests were performed before surgery and for seven days afterward. On the seventh postoperative day, patients performed a six-minute walk test and completed a functional difficulties questionnaire (FDQ).

Results

Pulmonary function test values reduced in all three groups postoperatively when compared to the preoperative values but improved by the seventh postoperative day (p < 0.05). On comparing the seventh postoperative day values to the preoperative values, the VS group had no significant difference (p = 1.00) (Forced Vital Capacity- % change: DB-37.76, VS-1.59, FS-27.98), indicating that the value had nearly returned to the baseline. As compared to the DB and FS groups, FVC showed a greater improvement in the VS group (p = 0.01 and p = 0.06 respectively). No significant differences were observed between groups for distance walked (p > 0.05), however, FDQ scores demonstrated positive changes in favor of VS when contrasted with FS or DB (p < 0.05).

Conclusion

Diaphragmatic breathing, flow or volume-oriented spirometer could improve pulmonary function in the postoperative period. The volume-oriented spirometer, however, was found to be the most beneficial among the three techniques in improving patients’ pulmonary function and daily life functional tasks. Further research is warranted to confirm these findings.

•

The present pilot randomized clinical trial is the first of a kind that exhibits the effects of three breathing exercises in patients following valve replacement cardiac surgery.

•

The study demonstrates the individual and contrasting effects of volume spirometry, volume spirometry and deep breathing exercise between preoperative day until postoperative day 7 in terms of pulmonary function and function activities.

Evaluation of respiratory and peripheral muscle training in individuals undergoing myocardial revascularization

OBJECTIVES

To investigate the effect of peripheral muscle strength training (PMT) and respiratory muscle strength training (RMT) muscle strength training associated with conventional physical therapy on the respiratory muscle strength, functional capacity, and quality of life in the immediate postoperative period of patients undergoing coronary artery bypass graft (CABG).

METHODS

This was a randomized controlled trial. Eighty-three patients undergoing CABG were divided into two groups: Intervention group, patients that received PMT and RMT associated with conventional physical therapy, one session a day for 5 days; control group, patients that received conventional physical therapy, one session a day for 5 days. All patients had respiratory muscle strength, peripheral muscle strength, functional capacity, and quality of life evaluated by manovacuometry, dynamometry, 6-min walking test, and 36-item Short-Form Health Survey Questionnaire, respectively, before and 5 days after CABG.

RESULTS

Both groups showed a significantly reduced respiratory muscle strength after CABG; however, in the intervention group, the inspiratory muscle strength reduction was lower (confidence interval [CI] 95%: 2.29 [1.9; 27.54]). The quality of live domains for pain (CI 95%: 3.08 [5.21; 24.97]) and vitality perception (CI 95%: 2.51 [2.12; 19.53]) worsened in the control and improved in the intervention group (pain: CI 95%: 1.19 [-3.38; 13.09]; vitality CI 95%: 0.07 [-6.55; 7.04]). Both groups showed reduced functional capacity and expiratory muscle strength after CABG.

CONCLUSION

Conventional physical therapy combined with PMT and RMT may reduce inspiratory muscle strength loss and improve pain and vitality perception in the immediate postoperative period after CABG.

Effectiveness of postural lung recruitment on postoperative atelectasis assessed by lung ultrasound in children undergoing lateral thoracotomy cardiac surgery with cardiopulmonary bypass

OBJECTIVES

To assess the effects of postural lung recruitment maneuvers on the postoperative atelectasis assessed by lung ultrasound (LUS) compared with supine position recruitment maneuvers in children undergoing right lateral thoracotomy cardiac surgery with cardiopulmonary bypass.

METHODS

In this randomized and controlled trial, 84 patients aged 3 years or younger, scheduled for right lateral thoracotomy cardiac surgery with cardiopulmonary bypass (CPB) were randomly allocated to postural lung recruitment group or control group. The first LUS exam was performed immediately upon completion of the cardiac surgery (T1), and a repeat ultrasound exam started 1 min after lung recruitment maneuvers (T2). The primary outcome was the incidence of significant atelectasis at T2.

RESULTS

The incidence of significant atelectasis at T2 in the postural lung recruitment maneuver group was lower compared with that in the control group (30.2% vs. 58.1%; odds ratio: 0.31; 95% confidence interval: 0.13-0.76; p = .009). The LUS scores for consolidations and B-lines of the left lung were higher than those of the right lung in both groups at T1. More significant reduction of the left LUS scores and sizes of atelectatic areas were found in the postural lung recruitment group than those in the control group.

CONCLUSIONS

Postoperative postural recruitment maneuver was more effective to improve reaeration of lung than supine position recruitment maneuver in children undergoing right lateral thoracotomy cardiac surgery with CPB.

High Flow Oxygen Therapy at Two Initial Flow Settings versus Conventional Oxygen Therapy in Cardiac Surgery Patients with Postextubation Hypoxemia: A Single-Center, Unblinded, Randomized, Controlled Trial

In cardiac surgery patients with pre-extubation PaO₂/inspired oxygen fraction (FiO₂) < 200 mmHg, the possible benefits and optimal level of high-flow nasal cannula (HFNC) support are still unclear; therefore, we compared HFNC support with an initial gas flow of 60 or 40 L/min and conventional oxygen therapy. Ninety nine patients were randomly allocated (respective ratio: 1:1:1) to I = intervention group 1 (HFNC initial flow = 60 L/min, FiO₂ = 0.6), intervention group 2 (HFNC initial flow = 40 L/min, FiO₂ = 0.6), or control group (Venturi mask, FiO₂ = 0.6). The primary outcome was occurrence of treatment failure. The baseline characteristics were similar. The hazard for treatment failure was lower in intervention group 1 vs. control (hazard ratio (HR): 0.11, 95% CI: 0.03–0.34) and intervention group 2 vs. control (HR: 0.30, 95% CI: 0.12–0.77). During follow-up, the probability of peripheral oxygen saturation (SpO₂) > 92% and respiratory rate within 12–20 breaths/min was 2.4–3.9 times higher in intervention group 1 vs. the other 2 groups. There was no difference in PaO₂/FiO₂, patient comfort, intensive care unit or hospital stay, or clinical course complications or adverse events. In hypoxemic cardiac surgery patients, postextubation HFNC with an initial gas flow of 60 or 40 L/min resulted in less frequent treatment failure vs. conventional therapy. The results in terms of SpO₂/respiratory rate targets favored an initial HFNC flow of 60 L/min.

Reduced inspiratory muscle strength increases pneumonia in patients with acute myocardial infarction

BACKGROUND

Inspiratory muscle strength is associated with pneumonia in patients after surgery or those with subacute stroke. However, inspiratory muscle strength in patients with acute myocardial infarction (AMI) has not been studied.

OBJECTIVE

To evaluate the predictive value of inspiratory muscle strength for pneumonia in patients with AMI.

METHODS

Patients with AMI were consecutively enrolled from March 2019 to September 2019. Measurements of maximal inspiratory pressure (MIP) were used to estimate inspiratory muscle strength and mostly were taken within 24 hr after culprit-vessel revascularization. Patients were divided into 3 groups by MIP tertile (T1: < 56.1 cm H2O, n = 88; T2: 56.1-84.9 cm H2O, n = 88; T3: > 84.9 cm H2O, n=89). The primary endpoint was in-hospital pneumonia.

RESULTS

Among 265 enrolled patients, pneumonia developed in 26 (10%). The rates of pneumonia were decreased from MIP T1 to T3 (T1: 17%, T2: 10%, T3: 2%, P = 0.004). In-hospital all-cause mortality and major adverse cardiovascular events (MACEs) did not differ between groups. Multivariate logistic regression confirmed increased MIP associated with reduced risk of pneumonia (odds ratio 0.78, 95% confidence interval 0.65-0.94, P = 0.008). Receiver operating characteristic curve analysis indicated that MIP had good performance for predicting in-hospital pneumonia, with an area under the curve of 0.72 (95% confidence interval 0.64-0.81, P < 0.001).

CONCLUSIONS

The risk of pneumonia but not in-hospital mortality and MACEs was increased in AMI patients with inspiratory muscle weakness. Future study focused on training inspiratory muscle may be helpful.

Guidelines for enhanced recovery after cardiac surgery. Consensus document of Spanish Societies of Anesthesia (SEDAR), Cardiovascular Surgery (SECCE) and Perfusionists (AEP)

The ERAS guidelines are intended to identify, disseminate and promote the implementation of the best, scientific evidence-based actions to decrease variability in clinical practice. The implementation of these practices in the global clinical process will promote better outcomes and the shortening of hospital and critical care unit stays, thereby resulting in a reduction in costs and in greater efficiency. After completing a systematic review at each of the points of the perioperative process in cardiac surgery, recommendations have been developed based on the best scientific evidence currently available with the consensus of the scientific societies involved.

Premobilization of CD133+ progenitors is associated with attenuated inflammation-induced pulmonary dysfunction following extracorporeal circulation in mice

OBJECTIVES

Progenitor cells mobilized by granulocyte colony-stimulating factor (G-CSF) have been shown to lessen acute kidney injury induced by extracorporeal circulation (ECC). Both acute kidney injury and lung injury are characterized by endothelial dysfunction. Our goal was to examine whether and how G-CSF-mobilized progenitors with endothelial capacity may help mitigate ECC-induced pulmonary dysfunction.

METHODS

G-CSF (10 μg/kg/day) was administered subcutaneously to C57BL/6 mice before or at the initiation of the ECC process, after which lung injury was assessed by measuring neutrophils in the fluid from bronchoalveolar lavage and determining the pathological score in lung tissue. CD133+ progenitors were isolated and injected into C57BL/6 mice before ECC in vivo. We incubated the CD133+ cells with pulmonary monocytes or neutrophils isolated from naïve mice in vitro.

RESULTS

Pretreatment with G-CSF for 2 days significantly decreased the number of neutrophils in the bronchoalveolar lavage fluid, and the pathological score (P < 0.01; n = 5) improved the PaO2/FiO2 ratio [193.4 ± 12.7 (ECC without G-CSF) vs 305.6 ± 22.6 mmHg (ECC with G-CSF); P = 0.03, n = 5] and suppressed neutrophil elastase and tumour necrosis factor-α levels in the circulation; we also observed increases in both circulating and pulmonary populations of CD133+ progenitors. Similar effects were observed in animals pretreated with CD133+ progenitors instead of G-CSF before ECC. The majority of CD133+/CD45- and CD133+/CD45+ progenitors were mobilized in the lung and in the circulation, respectively. Incubating CD133+ progenitors with neutrophils or pulmonary monocytes blocked lipopolysaccharide-induced release of inflammatory factors.

CONCLUSIONS

Our results suggest that pretreatment of G-CSF attenuates ECC-induced pulmonary dysfunction through inhibiting the inflammatory response in lung tissue and in the circulation with associated premobilization of CD133+ progenitors.

Opportunities for patients to engage in postoperative recovery following cardiac surgery: A systematic narrative review

OBJECTIVE

To compare patient booklets with clinical guidelines and care pathways to assess: gaps in content and depth of information delivered, opportunities for patients participation and to review the trajectory of care to inform recovery.

METHODS

A systematic review of the grey literature was conducted using Google search engine and a variety of terms related to cardiac surgery, patient outcomes and recovery pathways. Patient books and care pathways were obtained from major hospitals in Melbourne. Resources were included if they were published between January 2013-August 2018 and written in English.

RESULTS

A total of 31 resources were included in the review, (n = 14 patient booklets, n = 17 clinician guides). Twenty-one topics of recovery were identified. Patient booklets provided information on more topics of recovery than clinician guides (50 % and 24 % respectively). Clinician guides provided more depth on information on topics of recovery than patient booklets (85 % and 73 % respectively). The majority of patient booklets outlined patient participation was in five topics of recovery.

CONCLUSIONS

Gaps in the type and depth of information exist between patient and clinician guidelines. Clearer guidelines on how patients can participate in care are needed.

PRACTICE IMPLICATIONS

Nurses are key drivers in facilitating patient participation in postoperative recovery.

Lung ultrasound evaluation of incremental PEEP recruitment maneuver in children undergoing cardiac surgery

AIM

To explore the effect of incremental positive end-expiratory pressure recruitment maneuver (iPEEPRM) in children with congenital heart diseases (CHDs) using lung ultrasound.

METHODS

Thirty-six children aged 3 months to 5 years scheduled for cardiac surgery participated. iPEEPRM was performed with PEEP stepwise increase (0-5-10-15 cmH₂ O) and decrease at the same rate before and after surgery. Atelectatic areas, ultrasound scores, arterial oxygen pressure (PaO₂ ), and respiratory system dynamic compliance per kilogram body weight (CDyn/kg) were analyzed before and after iPEEPRM. The primary outcome is the incidence of atelectasis. Secondary outcomes are oxygenation, ventilation, CDyn/kg, and atelectasis area.

RESULTS

iPEEPRM was successfully applied in 92% (33/36) children before surgery and 71% (24/34) children after surgery. The incidence of atelectasis was significantly reduced by iPEEPRM from 76% to 15% before surgery and from 92% to 38% after surgery, respectively (P < .001). Before surgery, iPEEPRM significantly reduced atelectatic areas and ultrasound scores: 32.5 (0-128.1) mm² vs 0 (0-0) mm² and 8 (3-12) vs 2 (0-4). PaO₂ and CDyn/kg were significantly increased after iPEEPRM: 243 (129-275) mm Hg vs 278 (207-323) mm Hg and 0.6 (0.4-0.7) mL/cmH₂ O/kg vs 0.8 (0.6-1.0) mL/cmH₂ O/kg. After surgery, iPEEPRM significantly reduced atelectatic areas and ultrasound scores: 45.7 (13.1-115.8) mm² vs 0 (0-34.7) mm² , and 9 (6-12) vs 3 (0-5). PaO₂ and CDyn/kg were also significantly increased after iPEEPRM.

CONCLUSIONS

iPEEPRM effectively reduced atelectasis, improved lung aeration, oxygenation, and CDyn/kg in children undergoing cardiac surgery.

Lung Ultrasonography and Cardiac Surgery: A Narrative Review

Pulmonary complications are common after cardiac surgery and are closely related to postoperative heart failure and adverse outcomes. Lung ultrasonography (LUS) is currently a widely accepted diagnostic approach with well-established methodology, nomenclature, accuracy, and prognostic value in numerous clinical conditions. The advantages of LUS are universally recognized and include bedside applicability, high diagnostic sensitivity and reproducibility, no radiation exposure, and low cost. However, routine perioperative ultrasonography during cardiac surgery generally is limited to echocardiography, diagnosis of pleural effusion, and as a diagnostic tool for postoperative complications in different organs, and few studies have explored the clinical outcomes in relation to LUS among cardiac patients. This narrative review presents the clinical evidence regarding LUS application in intensive care and during the perioperative period for cardiac surgery. Furthermore, this review describes the methodology and the diagnostic and prognostic accuracies of LUS. A summary of ongoing clinical trials evaluating the clinical outcomes related to LUS also is provided. Finally, this review discusses the rationale for upcoming clinical research regarding whether routine use of LUS can modify current intensive care practice and potentially affect the clinical outcomes after cardiac surgery.

The Effects of Escalation of Respiratory Support and Prolonged Invasive Ventilation on Outcomes of Cardiac Surgical Patients: A Retrospective Cohort Study

Objectives

The aim of this study was to determine the effects of escalation of respiratory support and prolonged postoperative invasive ventilation on patient-centered outcomes, and identify perioperative factors associated with these 2 respiratory complications.

Design

A retrospective cohort analysis of cardiac surgical patients admitted to the cardiothoracic intensive care unit (ICU) between August 2015 and January 2018. Escalation of respiratory support was defined as “unplanned continuous positive airway pressure,” “non-invasive ventilation,” or “reintubation” after surgery; prolonged invasive ventilation was defined as “invasive ventilation beyond the first 12 hours following surgery.” The primary endpoint was the composite of escalation of respiratory support and prolonged ventilation.

Setting

Tertiary cardiothoracic ICU.

Participants

A total of 2,098 patients were included and analyzed.

Interventions

None.

Measurements and Main Results

The composite of escalation of support or prolonged ventilation occurred in 509 patients (24.3%). Patients who met the composite had higher mortality (2.9% v 0.1%; p < 0.001) and longer median [interquartile range] length of ICU (2.1 [1.0-4.9] v 0.9 [0.8-1.0] days; p < 0.0001) and hospital (10.6 [8.0-16.0] v 7.2 [6.2-10.0] days; p < 0.0001) stay. Hypoxemia and anemia on admission to ICU were the only 2 factors independently associated with the need for escalation of respiratory support or prolonged invasive ventilation.

Conclusions

Escalation of respiratory support or prolonged invasive ventilation is frequently seen in cardiac surgery patients and is highly associated with increased mortality and morbidity. Hypoxemia and anemia on admission to the ICU are potentially modifiable factors associated with escalation of respiratory support or prolonged invasive ventilation.

Nasal High Flow Versus Conventional Oxygen Therapy for Postoperative Cardiothoracic Surgery Patients

BACKGROUND

Reintubation and complications in postoperative cardiothoracic patients remain high despite medical advancements. A 2-year retrospective, observational study was conducted in postextubated cardiothoracic patients to assess the effectiveness of the current standard-conventional oxygen therapy (COT) compared with a nasal high flow (NHF) therapy.

OBJECTIVES

The objective of this study was to understand whether NHF therapy would reduce the need for reintubation and improve clinical outcomes after surgery.

METHOD

All consecutive postoperative patients who had same-day elective cardiothoracic surgery in a tertiary hospital were included. The 2013 data were from patients' charts who received COT, and the 2014 data were from patients' charts after the implementation of NHF therapy post extubation as a standard of care.

RESULTS

A total of 400 patient charts were analyzed: 221 and 179 patients in the COT and NHF, respectively. No significant difference was seen in the frequency of reintubation (P = .48). Despite both cohorts having the same length of stay (P = .10), patients treated with NHF required less time on supplemental oxygen (P = .001). Day 1 postoperative chest x-ray results did not show any significant differences between groups, whereas day 2 x-rays showed worsening results in the COT cohort (P < .001). Furthermore, the incidence of ventilator-associated pneumonia (VAP) post extubation was significantly higher in the COT cohort, with zero VAP episodes reported in the NHF cohort (P = .02).

DISCUSSION

Although this study was not able to demonstrate the reduction in reintubation between groups, the use of NHF compared with COT seems to reduce the time spent on oxygen therapy and decrease the rate of VAP. Further evidence including randomized controlled trials is required to determine the impact of NHF on reintubation and complications in postoperative cardiothoracic surgery.

Effect of cardiac surgery on respiratory muscle strength

Objectives

Pulmonary complications, such as atelectasis, pulmonary oedema, pleural effusion, bronchospasm, and pneumonia, have been reported following cardiac surgery. Shallow breathing leading to impaired lung function is the major cause of respiratory complications. Decreases in respiratory muscle strength can be measured using the maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) produced in the oral cavity. This study aimed to determine the decrease in respiratory muscle strength 8 weeks following cardiac surgery. Moreover, the relationship between lung function and respiratory muscle strength was studied.

Methods

In this observational study, 42 adult cardiac surgery patients (10 women, 32 men; mean age 65 ± 7 years) were investigated. Lung function and respiratory muscle strength were measured preoperatively and at 2 months postoperatively.

Results

The pre- and postoperative respiratory muscle strengths were in accordance with the predicted values. The MIP was 81.75 ± 22.04 cmH₂O preoperatively and 74.56 ± 18.86 cmH₂O at the 2-month follow-up (p = 0.146). The MEP was 98.55 ± 22.24 cmH₂O preoperatively and 88.86 ± 18.14 cmH₂O at the 2-month follow-up (p = 0.19). The preoperative lung function was in accordance with the predicted values; however, lung function significantly decreased postoperatively. At the 2-month follow-up, there was a moderate correlation between the MIP and forced expiratory volume (r = 0.59, p = 0 .0078).

Conclusions

The respiratory muscle strength was not impeded either before or 2 months after cardiac surgery. However, the exact mechanism for the alteration in lung function remains unclear. Measures to re-establish the ideal postoperative lung capacity should concentrate on different perioperative pulmonary exercises.

High-Flow Therapy by Nasal Cannulae Versus High-Flow Face Mask in Severe Hypoxemia After Cardiac Surgery: A Single-Center Randomized Controlled Study-The HEART FLOW Study

OBJECTIVE

To determine whether high-flow oxygen therapy by nasal cannulae (HFNC) is more effective than a high-flow face mask (HFFM) in severe hypoxemia.

DESIGN

Randomized, single-center, open-labeled, controlled trial.

SETTING

University Hospital of Nantes, France.

PARTICIPANTS

Cardiac surgery patients presenting oxygen saturation <96% with Venturi mask 50%.

INTERVENTION

Oxygenation by HFNC (45 L/min, F_IO₂ 100%) or Hudson RCI non-rebreather face mask with a reservoir bag (15 L/min).

MEASUREMENTS AND MAIN RESULTS

The co-primary outcomes were the PaO₂/F_IO₂ ratio at 1 and 24 hours. In the intent-to-treat analysis (90 patients), the mean (standard deviation) PaO₂/F_IO₂ ratios were: after 1 hour, 113.4 (50.2) in HFFM versus 137.8 (57.0) in HFNC (mean difference 24.4, CI 97.5% [2.9-45.9], p = 0.03), and after 24 hours, 106.9 (62.6) in HFFM versus 129.9 (54.0) in HFNC (mean difference 23.0, CI 97.5% [1.5-44.6], p = 0.04). After adjustment on baseline PaO₂/F_IO_2, this difference persisted at 24 hours (p = 0.04). For secondary outcomes, the PaO₂/F_IO₂ ratio after 6 hours was 108.7 (47.9) in HFFM versus 136.0 (45.2) in HFNC (p = 0.01), without difference after 48 hours (p = 0.95). Refractory hypoxemia requiring noninvasive ventilation occurred in 13 (28%) patients in HFNC versus 24 (56%) patients in HFFM (p = 0.007). The HFNC improved satisfaction (p = 0.0002) and reduced mucus dryness (p = 0.003) compared with HFFM.

CONCLUSION

In patients with severe hypoxemia after cardiac surgery, PaO₂/F_IO₂ at 1 and 24 hours were higher and the use of noninvasive ventilation was reduced in HFNC compared with HFFM.

Factors Associated with Postoperative Pain among Patients after Cardiac Surgery in the Tertiary Care Teaching Hospital of Karachi, Pakistan

Background

Pain is the subjective feeling of an individual, which affects the overall recovery of patients after cardiac surgery. Postoperative pain is the most inadequately managed symptom of cardiac surgery. Subsequently, there are many factors that can either hinder or facilitate pain management, including patients' beliefs, cultural values, physiological features, hospital policies, and healthcare providers' knowledge and beliefs. The purpose of this research was to identify factors associated with postoperative pain and its management, after cardiac surgery, among patients in a tertiary care hospital in Karachi, Pakistan.

Methods

Quantitative correlational study design was employed to attain the study purpose. Data were collected from 136 adult cardiac surgery patients admitted in the Cardiothoracic Surgery (CTS) Department, of tertiary care hospital. A self-developed questionnaire tool was used to gather information from patients. Data was then analyzed on SPSS version 19. Mann-Whitney U, Kruskal Wallis, and Spearman tests were applied to find the associations between the pain levels and of the independent variables.

Results

The mean pain scores of the first, second, and third postoperative days were found to be 2.98, 2.96, and 2.98, respectively. The findings also showed that BMI and the types of surgery were significantly associated with postoperative pain. Patients' beliefs regarding drug dependency, fear of adverse effects, and postoperative physical activities were also associated with pain. Furthermore, the nurses' education level and reluctance in medication administration due to fear of adverse effects were found to be significant too.

Conclusion

The study identified some of the important factors that were associated with postoperative pain. The results suggest the need for the enhancement of patients' education on drug dependency, adverse effects, and physical activity, before cardiac surgery. The nurses should be educated on pain management keeping the patients' culture and other perceptions of pain in mind.

Myofascial release in patients during the early postoperative period after revascularisation of coronary arteries

Purpose: The evaluation of the impact of soft tissue manual therapy with a myofascial release on pulmonary function, postoperative pain, fatigue, breathing difficulties and physical fitness, in patients during the early postoperative period after coronary artery bypass grafting and off-pump coronary artery bypass grafting surgery.Materials and methods: The study included 80 subjects (59 males) with an average age of 64.13 years old. They were randomised into two groups: group I (n = 40) received a conventional form of rehabilitation and group II (n = 40) additionally, from day 3 to day 6 post-surgery, was provided the Carol Manheim form of myofascial release. Subjects were evaluated three times: before the surgery, on day 4 and 6 post-surgery. Using the visual analogue scale, the following symptoms were measured: pain intensity, breathing difficulties and level of physical endurance. Fatigue after performing physical exercises was measured using the Borg scale. Spirometry was used to measure the one-second forced expiratory volume and forced vital capacity.Results: Positive changes were observed in both groups with regard to all analysed variables. However, group II compared to group I showed a significantly greater improvement (p < 0.05; the Mann-Whitney U test) in relation to: pain intensity on day 4 (mean 5.46 vs 6.58) and on day 6 (mean 3.05 vs 5.35) after the surgery; lower breathing difficulties on day 6 post-surgery (mean 4.08 vs 5.63); limiting physical fitness on day 6 post-surgery (mean 6.35 vs 5.13). Between the condition prior to the surgery and day 6 post-surgery in group II compared to group I, there was a significantly smaller (p < 0.05; Student's t-test) decrease in one-second forced expiratory volume (mean -0.65 vs -0.9 L/s) and the volume of forced vital capacity (mean -0.63 vs -1.33 L). Between day 4 and 6 post-surgery in group II compared to group I, there was a significantly higher (p < 0.05; Student's t-test) increase in the one-second forced expiratory volume (mean 0.21 vs 0.11 L/s) and forced vital capacity (mean 0.32 vs 0.12 L).Conclusions: Implementing myofascial release techniques in the conventional form of cardiosurgical rehabilitation might enhance the improvement in pulmonary function, lessen breathing difficulties, pain intensity and fatigue, it might augment the increase in physical endurance among patients during the early postoperative period after coronary artery bypass grafting and off-pump coronary artery bypass grafting surgery.Implications for rehabilitationThe implementation of myofascial release techniques in conventional cardiac rehabilitation may improve the pulmonary function in patients during the early postoperative period, after revascularisation of coronary arteries.The adoption of myofascial release techniques in conventional cardiac rehabilitation may decrease breathing difficulties, pain intensity, fatigue and increase the physical fitness in patients during the early postoperative period, after the revascularisation of the coronary arteries.The implementation of myofascial release techniques in conventional cardiac rehabilitation may enhance patients' improvement during the early postoperative period, after the revascularisation of the coronary arteries.

The effects of five days of intensive preoperative inspiratory muscle training on postoperative complications and outcome in patients having cardiac surgery: a randomized controlled trial

OBJECTIVE

To determine the prophylactic efficacy of short-term intensive preoperative inspiratory muscle training on the incidence of postoperative pulmonary complications in patients scheduled for cardiac surgery.

DESIGN

Single-blind, randomized controlled pilot study.

SETTING

TEDA International Cardiovascular Hospital, China.

SUBJECTS

In total, 197 subjects aged ⩾50 years scheduled for cardiac surgery were selected.

INTERVENTION

The intervention group ( n = 98) received five days of preoperative inspiratory muscle training on top of the usual care received by the patients in the control group ( n = 99).

MAIN MEASURES

The primary outcome variable was the occurrence of postoperative pulmonary complications. The secondary outcome variables were inspiratory muscle strength, lung function and length of hospitalization.

RESULTS

After cardiac surgery, a total of 10 (10.2%) of the 98 patients in the intervention group and 27 (27.3%) of 99 patients in the control group had postoperative pulmonary complications (risk ratio, 0.23; 95% confidence interval (CI), 0.09-0.58, P = 0.002). The study revealed that, compared with the control group, the intervention group had a significant increase in inspiratory muscle strength (by 10.48 cm H₂O, P < 0.001), forced expiratory volume in the first second of expiration (FEV1) %predicted (by 3.75%, P = 0.030), forced vital capacity (FVC) %predicted (by 4.15%, P = 0.008) and maximal voluntary ventilation (MVV) %predicted (by 6.44%, P = 0.034). Length of hospital stay was 7.51 (2.83) days in the intervention group and 9.38 (3.10) days in the control group ( P = 0.039).

CONCLUSION

A five-day intensive pattern of preoperative inspiratory muscle training reduced the incidence of postoperative pulmonary complications and duration of postoperative hospitalization in patients undergoing cardiac surgery.

Lung-diffusing capacity for carbon monoxide predicts early complications after cardiac surgery

PURPOSE

Preoperative pulmonary dysfunction has been associated with increased operative mortality and morbidity after cardiac surgery. This study aimed to determine whether values for the diffusing capacity of the lung for carbon monoxide (DL_CO) could predict postoperative complications after cardiac surgery.

METHODS

This study included 408 consecutive patients who underwent cardiac surgery between June 2008 and December 2015. DL_CO was routinely determined in all patients. A reduced DL_CO was clinically defined as %DL_CO < 70%. %DL_CO was calculated as DL_CO divided by the predicted DL_CO. The association between %DL_CO and in-hospital mortality was assessed, and independent predictors of complications were identified by a logistic regression analysis.

RESULTS

Among the 408 patients, 338 and 70 had %DL_CO values of ≥ 70% and < 70%, respectively. Complications were associated with in-hospital mortality (P < 0.001), but not %DL_CO (P = 0.275). A multivariate logistic regression analysis with propensity score matching identified reduced DL_CO as an independent predictor of complications (OR, 3.270; 95%CI, 1.356-7.882; P = 0.008).

CONCLUSIONS

%DL_CO is a powerful predictor of postoperative complications. The preoperative DL_CO values might provide information that can be used to accurately predict the prognosis after cardiac surgery.

CLINICAL TRIAL REGISTRATION NUMBER

UMIN000029985.

The effect of local anesthetic continuous wound infusion for the prevention of postoperative pneumonia after on-pump cardiac surgery with sternotomy: the STERNOCAT randomized clinical trial

PURPOSE

Postoperative pain after cardiac surgery, exacerbated by cough and sternal mobilization, limits clearance of bronchopulmonary secretions and may predispose to postoperative pneumonia. In this study, we tested the ability of local anesthetic continuous wound infusion to prevent pneumonia after cardiac surgery with sternotomy and cardiopulmonary bypass (CPB) owing to better analgesia and bronchopulmonary drainage.

METHODS

In this randomized, double-blind, placebo-controlled trial conducted in five academic centers, patients undergoing cardiac surgery with sternotomy and CPB were enrolled from February 2012 until November 2014, and were followed over 30 days. Patients were assigned to a 48-h infusion (10 ml h^-1) of L-bupivacaine (12.5 mg h^-1) or placebo (saline) via a pre-sternal multiperforated catheter. Anesthesia and analgesia protocols were standardized. The primary end point was the incidence of pneumonia during the study period, i.e., until hospital discharge or 30 days. We hypothesized a 30% reduction in the incidence of pneumonia.

RESULTS

Among 1493 randomized patients, 1439 completed the trial. Pneumonia occurred in 36/746 patients (4.9%) in the L-bupivacaine group and in 42/739 patients (5.7%) in the placebo group (absolute risk difference taking into account center and baseline risk of postoperative pneumonia, - 1.3% [95% CI - 3.4; 0.8] P = 0.22). In the predefined subgroup of patients at high risk, L-bupivacaine decreased the incidence of pneumonia (absolute risk difference, - 5.6% [95% CI - 10.0; - 1.1], P = 0.01).

CONCLUSIONS

After cardiac surgery with sternotomy, continuous wound infusion of L-bupivacaine failed to decrease the incidence of pneumonia. These findings do not support the use of local anesthetic continuous wound infusion in this indication. Further study should investigate its effect in high-risk patients.

TRIAL REGISTRATION

EudraCT Number: 2011-003292-10; Clinicaltrials.gov Identifier: NCT01648777.

What is the Role of Preoperative Breathing Exercises in Reducing Postoperative Atelectasis after CABG?

BACKGROUND

Atelectasis and hypoxemia are frequently reported after coronary artery bypass graft surgery (CABG). Some studies confirm the benefits of breathing exercises on pulmonary complications, but the efficacy of preoperative breathing exercises in patients undergoing CABG is controversial. In this study, the effect of preoperative breathing exercises on the incidence of atelectasis and hypoxemia in patients candidate for CABG was examined.

METHODS

In a single-blinded randomized clinical trial, 100 patients who were undergoing coronary artery bypass graft surgery were randomly allocated into two groups of experimental and control, each consisted of 50 patients. Before the operation, experimental group patients were enrolled in a protocol including deep breathing, cough and incentive spirometer. In the control group, hospital routine physiotherapy was implemented. All the patients received the hospital routine physiotherapy once a day for 2 to 3 minutes in the first four days postoperatively. Arterial blood gases and atelectasis were compared between groups.

RESULTS

There was no significant difference between groups in terms of atelectasis and hypoxemia (p Value>0.05).

CONCLUSION

Preoperative breathing exercise does not reduce pulmonary complications in patients undergoing CABG.

Lung Protection Strategies during Cardiopulmonary Bypass Affect the Composition of Blood Electrolytes and Metabolites-A Randomized Controlled Trial

Cardiac surgery with cardiopulmonary bypass (CPB) causes an acute lung ischemia-reperfusion injury, which can develop to pulmonary dysfunction postoperatively. This sub-study of the Pulmonary Protection Trial aimed to elucidate changes in arterial blood gas analyses, inflammatory protein interleukin-6, and metabolites of 90 chronic obstructive pulmonary disease patients following two lung protective regimens of pulmonary artery perfusion with either hypothermic histidine-tryptophan-ketoglutarate (HTK) solution or normothermic oxygenated blood during CPB, compared to the standard CPB with no pulmonary perfusion. Blood was collected at six time points before, during, and up to 20 h post-CPB. Blood gas analysis, enzyme-linked immunosorbent assay, and nuclear magnetic resonance spectroscopy were used, and multivariate and univariate statistical analyses were performed. All patients had decreased gas exchange, augmented inflammation, and metabolite alteration during and after CPB. While no difference was observed between patients receiving oxygenated blood and standard CPB, patients receiving HTK solution had an excess of metabolites involved in energy production and detoxification of reactive oxygen species. Also, patients receiving HTK suffered a transient isotonic hyponatremia that resolved within 20 h post-CPB. Additional studies are needed to further elucidate how to diminish lung ischemia-reperfusion injury during CPB, and thereby, reduce the risk of developing severe postoperative pulmonary dysfunction.

A perioperative surgeon-controlled open-lung approach versus conventional protective ventilation with low positive end-expiratory pressure in cardiac surgery with cardiopulmonary bypass (PROVECS): study protocol for a randomized controlled trial

Background

Postoperative pulmonary complications (PPCs) are frequent after on-pump cardiac surgery. Cardiac surgery results in a complex pulmonary insult leading to high susceptibility to perioperative pulmonary atelectasis. For technical reasons, ventilator settings interact with the surgical procedure and traditionally, low levels of positive end-expiratory pressure (PEEP) have been used. The objective is to compare a perioperative, multimodal and surgeon-controlled open-lung approach with conventional protective ventilation with low PEEP to prevent PPCs in patients undergoing cardiac surgery.

Methods/design

The perioperative open-lung protective ventilation in cardiac surgery (PROVECS) trial is a multicenter, two-arm, randomized controlled trial. In total, 494 patients scheduled for elective cardiac surgery with cardiopulmonary bypass (CPB) and aortic cross-clamp will be randomized into one of the two treatment arms. In the experimental group, systematic recruitment maneuvers and perioperative high PEEP (8 cmH2O) are associated with ultra-protective ventilation during CPB. In this group, the settings of the ventilator are controlled by surgeons in relation to standardized protocol deviations. In the control group, no recruitment maneuvers, low levels of PEEP (2 cmH2O) and continuous positive airway pressure during CPB (2 cmH2O) are used. Low tidal volumes (6–8 mL/kg of predicted body weight) are used before and after CPB in each group. The primary endpoint is a composite of the single PPCs evaluated during the first 7 postoperative days.

Discussion

The PROVECS trial will be the first multicenter randomized controlled trial to evaluate the impact of a perioperative and multimodal open-lung ventilatory strategy on the occurrence of PPCs after on-pump cardiac surgery. The trial design includes standardized surgeon-controlled protocol deviations that guarantee a pragmatic approach. The results will help anesthesiologists and surgeons aiming to optimize ventilatory settings during cardiac surgery.

Trial registration

Clinical Trials.gov, NCT 02866578. Registered on 15 August 2016. Last updated 11 July 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2967-y) contains supplementary material, which is available to authorized users.

Effect of high-flow nasal cannula oxygen therapy vs conventional oxygen therapy on adult postcardiothoracic operation: A meta-analysis

INTRODUCTION

The effect of high-flow nasal cannula (HFNC) on adult post cardiothoracic operation remains controversial. We conducted a meta-analysis of randomized controlled trials to evaluate the effect of HFNC and conventional oxygen therapy (COT) on postcardiothoracic surgery.

METHODS

A search was conducted in Embase, MEDLINE, Ovid, and Cochrane databases until December, 2017 for all the controlled study to compare HFNC with COT in adult postcardiothoracic surgery. Two authors extracted data and assessed the quality of each study independently. The meta-analysis was performed by using RevMan 5.3. The primary outcome was the rate of escalation of respiratory support rate and pulmonary complications; secondary outcome included the length of intensive care unit (ICU) stay and length of hospital stay and the rate of intubation.

RESULTS

Four studies that involved 649 patients were included in the analysis. No significant heterogeneity was found in outcome measures. Compared with COT, HFNC were associated with a significant reduction in the escalation of respiratory support (odds ratio [OR] = 0.44, 95% confidence interval [CI] = 0.29-0.66, P < .001) and pulmonary complications (OR = 0.28, 95% CI = 0.13-0.6, P = .001). There were no significant differences in the reintubation rate (OR = 0.33, 95% CI = 0.02-5.39, P = .43), length of ICU stay (weighted mean difference = 0.11; 95% CI = -0.44 -0.26, P = .14) or length of hospital stay (weighted mean difference = -0.15, 95% CI = -0.46 -0.17, P = .36) between the 2 groups. No severe complications were reported in either group.

CONCLUSION

The HFNC could reduce respiratory support and pulmonary complications, and it could be safely administered for adult postcardiothoracic surgery. Further large-scale, randomized, and controlled trials are needed to update this finding.

Bilateral sternal infusion of ropivacaine and length of stay in ICU after cardiac surgery with increased respiratory risk: A randomised controlled trial

BACKGROUND

The continuous bilateral infusion of a local anaesthetic solution around the sternotomy wound (bilateral sternal) is an innovative technique for reducing pain after sternotomy.

OBJECTIVE

To assess the effects of the technique on the need for intensive care in cardiac patients at increased risk of respiratory complications.

DESIGN

Randomised, observer-blind controlled trial.

SETTING

Single centre, French University Hospital.

PATIENTS

In total, 120 adults scheduled for open-heart surgery, with one of the following conditions: age more than 75 years, BMI >30 kg m, chronic obstructive pulmonary disease, active smoking habit.

INTERVENTION

Either a bilateral sternal infusion of 0.2% ropivacaine (3 ml h through each catheter; 'intervention' group), or standardised care only ('control' group). Analgesia was provided with paracetamol and self-administered intravenous morphine.

MAIN OUTCOME MEASURES

The length of time to readiness for discharge from ICU, blindly assessed by a committee of experts.

RESULTS

No effect was found between groups for the primary outcome (P = 0.680, intention to treat); the median values were 42.4 and 37.7 h, respectively for the control and intervention groups (P = 0.873). Similar nonsignificant trends were noted for other postoperative delays. Significant effects favouring the intervention were noted for dynamic pain, patient satisfaction, occurrence of nausea and vomiting, occurrence of delirium or mental confusion and occurrence of pulmonary complications. In 12 patients, although no symptoms actually occurred, the total ropivacaine plasma level exceeded the lowest value for which neurological symptoms have been observed in healthy volunteers.

CONCLUSION

Because of a small size effect, and despite significant analgesic effects, this strategy failed to reduce the time spent in ICU.

TRIAL REGISTRATION

EudraCT (N°: 2012-005225-69); ClinicalTrials.gov (NCT01828788).

Effect of ulinastatin on interleukins and pulmonary function in bypass patients: a meta-analysis of randomized controlled trials

BACKGROUND

Our aim was to evaluate the effect of urinary trypsin inhibitors (UTI) on interleukin, tumor necrosis factor-α (TNF-α), and polymorphonuclear neutrophil elastase (PMNE) levels as well as on pulmonary function in patients undergoing cardiopulmonary bypass.

MATERIALS AND METHODS

We searched the following databases for relevant studies: PubMed, Medline (Ovid SP), Cochrane Library, Wanfang Data, China Biology Medicine Database, Chinese Periodical Database, China Knowledge Resource Integrated Database, and Chinese Clinical Trial Registry. Two investigators independently collected the data and assessed the quality of each study. RevMan 5.3 was used for the meta-analysis.

RESULTS

In total, 15 randomized controlled trials (646 patients) met the inclusion criteria. There was a significant decrease in TNF-α, interleukin-6 (IL-6), IL-8, and PMNE levels at 6 h and 24 h after UTI treatment and an increase in IL-10 levels; additionally, there was a decrease in respiratory index and an improvement in the oxygenation index. Nevertheless, UTI treatment did not affect the length of intensive care unit stay, alveolar-arterial oxygen partial pressure difference, adverse lung events, or hospital mortality. Because of the high heterogeneity of the included trials, the results should be assessed carefully.

CONCLUSION

UTI treatment can suppress proinflammatory cytokine elevation and upregulate the release of anti-inflammatory mediators, thereby reducing pulmonary injury and improving pulmonary function after cardiopulmonary bypass.

Chronic Obstructive Pulmonary Disease and Off-Pump Coronary Surgery

PURPOSE

To determine to what extent chronic obstructive pulmonary disease (COPD) affects mortality and morbidity rates in patients treated with off-pump coronary artery bypass graft (CABG).

METHODS

A total of 321 patients treated with off-pump CABG were included in the present study. Of the 321 patients, 46 patients had COPD and they were designated as Group 1 and the remaining 275 patients did not have COPD and they were considered as Group 2. We compared the data obtained from the patients in both groups.

RESULTS

While preoperative spirometry values and arterial blood gas oxygen saturation levels were significantly lower, the partial values of carbon dioxide were higher in Group 1. Likewise, extubation time, the amount of drainage and blood transfusion, inotropic support, prolonged intubation, pulmonary complications, the use of bronchodilators, and steroids were statistically higher in Group 1 when compared with Group 2. Overall, there was no marked difference between the two groups in terms of mortality incidence.

CONCLUSION

We found similar morbidity and mortality rates among the patients with COPD and without COPD when they were treated with off-pump CABG. Therefore, the present results indicate that the presence of COPD is not associated with in-hospital mortality or severe morbidity post-CABG by off-pump approach.