Effect of prophylactic non-invasive mechanical ventilation on functional capacity after heart valve replacement: a clinical trial

Effects of Non-Invasive Ventilation with different modalities in patients undergoing heart surgery: Protocol for a randomized controlled clinical trial

INTRODUCTION

The thoracic surgical procedure leads to a reduction in respiratory muscle strength. To restore it, certain strategies must be employed. Physiotherapy utilizes resources and techniques such as deep breathing stimulation, cough stimulation, use of incentive spirometers, mobilization, and ambulation. However, at times these resources and techniques may prove insufficient, and additional measures, such as Non-Invasive Ventilation (NIV), are employed Pieczkoski (2017). Non-Invasive Positive Pressure Ventilation (NPPV) has been utilized to expedite pulmonary function recovery as well as to prevent and treat postoperative pulmonary complications Nasrala 2018. NIV diminishes the risk of ventilator-associated complications due to its non-invasive nature. Consequently, NIV has been adopted to avert post-extubation complications in postoperative patients Liu 2020. The objective of this study is to conduct a randomized clinical trial and assess the efficacy of NIV in comparison to conventional physiotherapy in terms of pulmonary function among patients undergoing cardiac surgery at a selected hospital in Campina Grande, Paraíba, Brazil.

METHODS AND ANALYSES

This randomized, controlled, double-blind (patient and analyst) clinical trial will be conducted at Hospital João XXIII in Campina Grande, Paraíba, Brazil. Patients do not know which group they are allocated to. Those in the group that use CPAP or BIPAP will not be able to distinguish one from the other. The data analyst at the end of the collections will also be blinded. Only the health professional who will be applying the protocol cannot be blinded. The sample size, determined via sample calculation, yielded a total of 21 patients per group (63 patients). The patients will be allocated into 3 groups (CPAP group - CPAP + standard physiotherapy, BiPAP group - BiPAP + standard physiotherapy, and Control group - standard physiotherapy) in a 1:1:1 allocation ratio. The control group will receive the usual physiotherapeutic treatment as per the kinesiotherapy protocol. The treatment will be administered twice daily, starting in the ICU and progressing to the ward. In the CPAP group, nasal CPAP at 10cmH2O will be administered for 1 hour, twice daily, using an approved device. In the BiPAP group, nasal BiPAP with an IPAP of 13cmH2O and EPAP of 8cmH2O will be administered for 1 hour, twice daily, using an approved device. The NIV sessions will be conducted over the course of 5 days of hospitalization, both in the ICU and the ward. Assessments will be conducted at two time points: on day 1 preoperatively and on day 5 postoperatively. The following measures will be evaluated: pulmonary function, length of hospital stay, presence of postoperative pulmonary complications, score of the Minnesota Living with Heart Failure Questionnaire (MLHFQ) in its Portuguese version, functional capacity, the Global Perception of Change Scale, and the Functional Independence Measure (MIF). The normality of variables will be assessed using the Shapiro-Wilk test. IBM SPSS Statistics Base 25.0, using the Shapiro-Wilk test for normality and paired Student's t-test for pre-post intervention comparison. They will use linear mixed effects models for longitudinal analysis and GLMMs to compare NIV effects over time between groups. They will employ ITT for missing data, INAR models for time dependence, fixed effects models for endogeneity, and Cohen's d for effect sizes. Parametric model assumptions will be checked, and various models will be considered for data characteristics.

PRIMARY OUTCOMES

Pulmonary function, Length of hospital stay.

SECOND OUTCOMES

Score of the Minnesota Living with Heart Failure Questionnaire (MLHFQ) in Portuguese version, Funcional capacity, The global perception of change scale, The functional independence measure (MIF), pO2 (partial pressure of oxygen), pCO2 (partial pressure of carbon dioxide), HCO3 (bicarbonate), Arterial Oxygen Saturation (SaO2), Base Excess (BE), Presence of lung complications.

OTHER PRE-SPECIFIED OUTCOMES

Duration of cardiopulmonary bypass, type of surgery, personal history, preoperative ejection fraction, previous respiratory complications, body mass index (BMI), gender and age.

TRIAL REGISTRATION

Trial register number NCT05966337.

[Non-invasive Mechanical Ventilation in Acute Respiratory Failure. Clinical Practice Guidelines - on behalf of the German Society of Pneumology and Ventilatory Medicine]

The guideline update outlines the advantages as well as the limitations of NIV in the treatment of acute respiratory failure in daily clinical practice and in different indications.Non-invasive ventilation (NIV) has a high value in therapy of hypercapnic acute respiratory failure, as it significantly reduces the length of ICU stay and hospitalization as well as mortality.Patients with cardiopulmonary edema and acute respiratory failure should be treated with continuous positive airway pressure (CPAP) and oxygen in addition to necessary cardiological interventions. This should be done already prehospital and in the emergency department.In case of other forms of acute hypoxaemic respiratory failure with only mild or moderately disturbed gas exchange (PaO2/FiO2 > 150 mmHg) there is no significant advantage or disadvantage compared to high flow nasal oxygen (HFNO). In severe forms of ARDS NIV is associated with high rates of treatment failure and mortality, especially in cases with NIV-failure and delayed intubation.NIV should be used for preoxygenation before intubation. In patients at risk, NIV is recommended to reduce extubation failure. In the weaning process from invasive ventilation NIV essentially reduces the risk of reintubation in hypercapnic patients. NIV is regarded useful within palliative care for reduction of dyspnea and improving quality of life, but here in concurrence to HFNO, which is regarded as more comfortable. Meanwhile NIV is also recommended in prehospital setting, especially in hypercapnic respiratory failure and pulmonary edema.With appropriate monitoring in an intensive care unit NIV can also be successfully applied in pediatric patients with acute respiratory insufficiency.

Effect of postoperative high load long duration inspiratory muscle training on pulmonary function and functional capacity after mitral valve replacement surgery: A randomized controlled trial with follow-up

Objectives

Although, pre-operative inspiratory muscle training has been investigated and reported to be an effective strategy to reduce postoperative pulmonary complications, the efficacy of postoperative inspiratory muscle training as well as the proper load, frequency, and duration necessary to reduce the postoperative pulmonary complications has not been fully investigated. This study was designed to investigate the effect of postoperative high-load long-duration inspiratory muscle training on pulmonary function, inspiratory muscle strength, and functional capacity after mitral valve replacement surgeries.

Design

Prospective randomized controlled trial.

Methods

A total of one hundred patients (mean age 38.3±3.29years) underwent mitral valve replacement surgery were randomized into experimental (n = 50) and control (n = 50) groups. The control group received conventional physiotherapy care, while experimental group received conventional care in addition to inspiratory muscle training, with 40% of the baseline maximal inspiratory pressure targeting a load of 80% by the end of the 8 weeks intervention protocol. Inspiratory muscle training started on the patient’s first day in the inpatient ward. Lung functions, inspiratory muscle strength, and functional capacity were evaluated using a computer-based spirometry system, maximal inspiratory pressure measurement and 6MWT respectively at 5 time points and a follow-up assessment was performed 6 months after surgery. Repeated measure ANOVA and post-hoc analyses were used (p <0.05).

Results

Group-time interactions were detected for all the studied variables (p<0.001). Between-group analysis revealed statistically significant postoperative improvements in all studied variables in the experimental group compared to the control group (p <0.001) with large effect size of η² ˃0.14. Within-group analysis indicated substantial improvements in lung function, inspiratory pressure and functional capacity in the experimental group (p <0.05) over time, and these improvements were maintained at follow-up.

Conclusion

High intensity, long-duration postoperative inspiratory muscle training is highly effective in improving lung function, inspiratory muscle strength, and functional capacity after mitral valve replacement surgeries.

Preventive Effect of Albumin Nano TPA Gene Plasmid Ultrasound Microbubble Carrier System on Thrombosis after Cardiac Valve Replacement

After cardiac valve replacement, most patients will have different degrees of thrombosis, different parts of the thrombus, and even more frequent occurrence of postoperative thrombosis; therefore, the prevention of postoperative thrombosis is particularly important. The purpose of this study was to investigate the preventive effect of albumin nano tPA gene plasmid ultrasound microbubble carrier system on thrombosis, especially in cardiac valve. The experimental control method was used. Firstly, 11 dogs meeting the experimental requirements were selected. Secondly, the data of albumin nanoparticles and microbubbles were analyzed. The average size of albumin particles was 132.0 nm, the average size of microbubbles was 3.1 ± 1.6 μm, and the zeta potential was 13.70 ± 1.95 MV. The concentration of microbubbles was 4.2 ± 1.3 × 10/ml. Finally, 11 dogs were divided into two groups. The experimental group was treated with albumin nanoparticles ultrasound microbubble, and the others were the control group. It was found that the levels of tPA and D-dimer in the experimental group were significantly increased and maintained at a high level at 1 week after operation, and the prothrombin time was detected and the international normalized ratio was calculated at the same time. No significant changes were found in the experimental group.

Effects of non-invasive ventilation in subjects undergoing cardiac surgery on length of hospital stay and cardiac-pulmonary complications: a systematic review and meta-analysis

Background

Cardiac surgery often leads to pulmonary complications. Non-invasive ventilation (NIV) is a mechanical ventilation modality that may help to prevent the pulmonary complications, and the role of the prophylactic use of NIV in patients after cardiac surgery remains controversial.

Methods

We searched PubMed, Embase, Web of Science and Cochrane Central for randomized controlled trials comparing the use of NIV (continues positive airway pressure or bi-level positive airway pressure) with standard treatment in post-cardiac surgery subjects without language restriction. Two investigators screened the eligible studies up to July, 2019. Meta-analysis using random effect model or fixed effect model was conducted for pulmonary complications, mortality, rate of reintubation and cardiac complications, and mean difference (MD) or standard mean difference for length of hospital stay and length of ICU stay.

Results

We included nine randomized controlled trails with 830 subjects. The use of NIV failed to reduce the risk of pulmonary complications, including atelectasis [risk rate (RR) 0.60; 95% confidence interval (CI): 0.28 to 1.28, P=0.19] and pneumonia (RR 0.27; 95% CI: 0.05 to 1.64, P=0.16). However, it has shortened the length of ICU stay (MD -1.00 h, 95% CI: -1.38 to -0.63, P<0.00001) and the length of hospital stay (MD -1.00 d, 95% CI: -1.12 to -0.87, P<0.00001). NIV also failed to reduce the rate of reintubation (RR 0.68; 95% CI: 0.21 to 2.26, P=0.53) or the risk of cardiac complications (RR 0.81; 95% CI: 0.59 to 1.13, P=0.22).

Conclusions

The prophylactic use of NIV immediately in post-cardiac subjects who underwent cardiac surgery might be able to shorten the length of hospital stay and the length of ICU stay, but it has no significant effect on pulmonary complications, rate of reintubation or cardiac complications.

Comparative clinical features and short-term outcomes of gastric and small intestinal gastrointestinal stromal tumours: a retrospective study

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the gastrointestinal tract. Recent research has shown that small intestinal GISTs exhibit more aggressive features than gastric GISTs. To compare the clinical features of gastric and small intestinal GISTs for the further prediction of different prognoses, we conducted a retrospective study. 43 patients in the small intestine group and 97 in the gastric group were collected between January 2016 and December 2017. Data on demographics, preoperative lab results, clinicopathological results and surgical management were compared between groups. Significant elements were subsequently included in logistic regression analysis for further identification. The Kaplan-Meier method and log-rank test were used to calculate the relapse-free survival (RFS) rate and cumulative survival rate. Univariable analysis demonstrated that underlying disease, gastrointestinal (GI) bleeding, lymphocyte count, haemoglobin (Hb), albumin (ALB), platelet-to-lymphocyte ratio (PLR), thrombin time (TT), National Institutes of Health (NIH) category, Dog1, surgical procedure types and postoperative hospitalization were different between the two groups. Among these factors, logistic regression analysis identified that patients in small intestinal group exhibited significantly higher GI bleeding rate (p = 0.022), NIH category (p = 0.031), longer postoperative hospitalization time (p = 0.001) with lower TT value (p = 0.030) than those in gastric group. The log-rank test indicated that the location of the GIST (p = 0.022), GIST with GI bleeding (p = 0.027) and NIH category (p = 0.031) were independent prognostic predictors for poor outcome regarding RFS. Regarding cumulative survival, only the location of the GIST (p = 0.027) was an independent prognostic predictor for poor outcome. Thus, we concluded that small intestine GISTs were associated with lower TT, recurrent GI bleeding, advanced NIH category and extended postoperative hospitalization. Nevertheless, future multicentre prospective study are expected to validate our results.

Prolonged use of noninvasive positive pressure ventilation after extubation among patients in the intensive care unit following cardiac surgery: The predictors and its impact on patient outcome

This retrospective, observational cohort study aimed to determine the independent risk factors and impact of prolonged non-invasive positive pressure ventilation (NIPPV) after extubation among patients in the intensive care unit following cardiac surgery. Patients who received prophylactic NIPPV after extubation were categorized into prolonged (NIPPV duration >3 days, n = 83) and non-prolonged groups (NIPPV duration ≤3 days, n = 105). The perioperative characteristics and hospital outcomes were recorded. The multivariate analyses identified the preoperative residual volume/total lung capacity (RV/TLC) ratio (adjusted odds ratio [AOR]: 1.10; 95% CI:1.01–1.19, p = 0.022) and postoperative acute kidney injury (AKI) with Kidney Disease Improving Global Outcomes (KDIGO) stage 2–3, 48 h after surgery (AOR: 3.87; 95% CI:1.21–12.37, p = 0.023) as independent predictors of prolonged NIPPV. Patients with both RV/TLC ratio > 46.5% and KDIGO stage 2–3 showed a highly increased risk of prolonged NIPPV (HR 27.17, p = 0.010), which was in turn associated with higher risk of postoperative complications and prolonged ICU and hospital stays. Preoperative RV/TLC ratio and postoperative AKI could identify patients at higher risk for prolonged NIPPV associated with poor outcomes. These findings may allow early recognition of patients who are at a higher risk for prolonged NIPPV, and help refine the perioperative management and critical care.

Noninvasive ventilation in acute respiratory failure: which recipe for success?

Noninvasive positive-pressure ventilation (NPPV) to treat acute respiratory failure has expanded tremendously over the world in terms of the spectrum of diseases that can be successfully managed, the locations of its application and achievable goals.

The turning point for the successful expansion of NPPV is its ability to achieve the same physiological effects as invasive mechanical ventilation with the avoidance of the life-threatening risks correlated with the use of an artificial airway.

Cardiorespiratory arrest, extreme psychomotor agitation, severe haemodynamic instability, nonhypercapnic coma and multiple organ failure are absolute contraindications for NPPV. Moreover, pitfalls of NPPV reduce its rate of success; consistently, a clear plan of what to do in case of NPPV failure should be considered, especially for patients managed in unprotected setting. NPPV failure is likely to be reduced by the application of integrated therapeutic tools in selected patients handled by expert teams.

In conclusion, NPPV has to be considered as a rational art and not just as an application of science, which requires the ability of clinicians to both choose case-by-case the best “ingredients” for a “successful recipe” (i.e.patient selection, interface, ventilator, interface,etc.) and to avoid a delayed intubation if the ventilation attempt fails.