Short-term perioperative treatment with ambroxol reduces pulmonary complications and hospital costs after pulmonary lobectomy: a randomized trial

Evaluation of safety and efficacy of inhaled ambroxol in hospitalized adult patients with mucopurulent sputum and expectoration difficulty

Background

Ambroxol is a widely used mucoactive drug in sputum clearance of respiratory diseases taken orally and by injection. However, there is a paucity of evidence for inhaled ambroxol in sputum clearance.

Methods

This study performed a multicenter, randomized, double-blind, placebo-controlled, phase 3 trial at 19 centers in China. Hospitalized adult patients with mucopurulent sputum and expectoration difficulty were recruited. Patients were randomized by 1:1 to receive inhalation of either ambroxol hydrochloride solution 3 mL (22.5 mg) + 0.9% sodium chloride 3 mL or 0.9% sodium chloride 6 mL twice daily for 5 days, with an interval of more than 6 h. The primary efficacy endpoint was the absolute change in the sputum property score after treatment compared to the baseline in the intention-to-treat population.

Results

Between 10 April 2018 and 23 November 2020, 316 patients were recruited and assessed for eligibility, of whom 138 who received inhaled ambroxol and 134 who received a placebo were included. Patients who received inhaled ambroxol had a significantly greater decrease in the sputum property score compared with patients who received inhalation of placebo (difference: -0.29; 95% CI: -0.53 to -0.05; p = 0.0215). Compared with the placebo, inhaled ambroxol also significantly reduced more expectoration volume in 24 h (difference: -0.18; 95% CI: -0.34 to -0.03; p  = 0.0166). There was no significant difference in the proportion of adverse events between the two groups, and no deaths were reported.

Discussion

In hospitalized adult patients with mucopurulent sputum and expectoration difficulty, inhaled ambroxol was safe and effective for sputum clearance compared with a placebo.

Clinical trial registration

[https://www.chictr.org.cn/showproj.html?proj=184677], Chinese Clinical Trial Registry [ChiCTR2200066348].

Comparison of Clinical Effectiveness Between Ambroxol and N-Acetylcysteine in Surgical Patients: A Retrospective Cohort Study

Postoperative pulmonary complications (PPCs) are a major cause of postoperative morbidity, mortality, and longer hospital stays. Expectorants are widely used during the perioperative period to reduce PPCs. This study aimed to compare the clinical effectiveness between ambroxol (AMB) and N-acetylcysteine (NAC) in patients undergoing surgery. A multicenter, retrospective cohort study was conducted using deidentified medical records from hospital information system. Between July 1, 2015, and November 30, 2017, patients aged ≥18 years, who received intravenous AMB or nebulized NAC as the only expectorant therapy for >3 days during their hospitalization for thoracic, abdominal, and neurosurgery, were included in this study. The clinical outcomes were evaluated, and propensity score matching was used to adjust significant differences between 2 groups. A total of 4025 cases in the AMB group and 2062 in NAC group after propensity score matching were identified. The incidence of PPCs (13.9% vs 11.6%; P = .013), postoperative sputum suction (17.2% vs 8.0%; P < .001), intensive care unit admission after surgery (25.1% vs 22.5%; P = .024), and postoperative mechanical ventilation (22.3% versus 17.5%; P < .001) in the AMB group were all significantly higher than those in the NAC group. This study suggested that patients treated with NAC during the perioperative period had a significantly lower risk of PPCs. However, further prospective study is needed to ensure the replicability of our findings.

Pulmonary surfactants affinity Pluronic-hybridized liposomes enhance the treatment of drug-resistant lung cancer

For a long time, the incidence and mortality of lung cancer have ranked first among all kinds of cancers, of which the major type is non-small cell lung cancer (NSCLC). Until now, chemotherapy and radiotherapy are still the first choice for patients with advanced or metastatic NSCLC. However, the emergence of multi-drug resistance (MDR) always leads to the failure of chemotherapy and increases cancer-related mortality. In this study, we prepared a Pluronic-hybridized paclitaxel-loaded liposome (PPL), which was used in combination with ambroxol (Ax) to not only resensitize drug-resistant tumor cells, but also increase the preparation retention in the lung. On the one hand, Ax induced the production of pulmonary surfactants (PS) and responsively improved the accumulation of pulmonary surfactants affinity liposomes whose skeleton was exogenous pulmonary surfactant phospholipids DPPC, because of the specific affinity of phospholipids related to pulmonary surfactant proteins. On the other hand, drug-resistant tumor cells were resensitized due to the inhibition of autophagy by Ax and the reduced expression of the drug-resistant protein P-glycoprotein (P-gp) by Pluronic P105. Therefore, we concluded that the combination of PPL and Ax achieved excellent killing tumor effects through multi-path and multi-strategy, having great application prospects in the future.

Perioperative interventions for prevention of postoperative pulmonary complications: systematic review and meta-analysis

OBJECTIVE

To identify, appraise, and synthesise the best available evidence on the efficacy of perioperative interventions to reduce postoperative pulmonary complications (PPCs) in adult patients undergoing non-cardiac surgery.

DESIGN

Systematic review and meta-analysis of randomised controlled trials.

DATA SOURCES

Medline, Embase, CINHAL, and CENTRAL from January 1990 to December 2017.

ELIGIBILITY CRITERIA

Randomised controlled trials investigating short term, protocolised medical interventions conducted before, during, or after non-cardiac surgery were included. Trials with clinical diagnostic criteria for PPC outcomes were included. Studies of surgical technique or physiological or biochemical outcomes were excluded.

DATA EXTRACTION AND SYNTHESIS

Reviewers independently identified studies, extracted data, and assessed the quality of evidence. Meta-analyses were conducted to calculate risk ratios with 95% confidence intervals. Quality of evidence was summarised in accordance with GRADE methods. The primary outcome was the incidence of PPCs. Secondary outcomes were respiratory infection, atelectasis, length of hospital stay, and mortality. Trial sequential analysis was used to investigate the reliability and conclusiveness of available evidence. Adverse effects of interventions were not measured or compared.

RESULTS

117 trials enrolled 21 940 participants, investigating 11 categories of intervention. 95 randomised controlled trials enrolling 18 062 participants were included in meta-analysis; 22 trials were excluded from meta-analysis because the interventions were not sufficiently similar to be pooled. No high quality evidence was found for interventions to reduce the primary outcome (incidence of PPCs). Seven interventions had low or moderate quality evidence with confidence intervals indicating a probable reduction in PPCs: enhanced recovery pathways (risk ratio 0.35, 95% confidence interval 0.21 to 0.58), prophylactic mucolytics (0.40, 0.23 to 0.67), postoperative continuous positive airway pressure ventilation (0.49, 0.24 to 0.99), lung protective intraoperative ventilation (0.52, 0.30 to 0.88), prophylactic respiratory physiotherapy (0.55, 0.32 to 0.93), epidural analgesia (0.77, 0.65 to 0.92), and goal directed haemodynamic therapy (0.87, 0.77 to 0.98). Moderate quality evidence showed no benefit for incentive spirometry in preventing PPCs. Trial sequential analysis adjustment confidently supported a relative risk reduction of 25% in PPCs for prophylactic respiratory physiotherapy, epidural analgesia, enhanced recovery pathways, and goal directed haemodynamic therapies. Insufficient data were available to support or refute equivalent relative risk reductions for other interventions.

CONCLUSIONS

Predominantly low quality evidence favours multiple perioperative PPC reduction strategies. Clinicians may choose to reassess their perioperative care pathways, but the results indicate that new trials with a low risk of bias are needed to obtain conclusive evidence of efficacy for many of these interventions.

STUDY REGISTRATION

Prospero CRD42016035662.

Interventions to avoid pulmonary complications after lung cancer resection

Surgical resection of lung cancer is the preferred treatment for early-stage disease in medically fit patients. The rates of postoperative pulmonary complications (PPCs) such as pneumonia, empyema and atelectasis are as high as 10% in contemporary series. A review of the literature was performed to identify the best evidence supporting interventions to identify, prevent and treat PPCs. The use of patient risk scores, appropriate choice of antibiotic prophylaxis, intraoperative ventilatory strategies, chest physiotherapy, sputum management and non-invasive ventilatory support were specifically discussed, as was the relevant supporting data. Recommendations to guide best practice and inform future research questions are outlined.

[More than expectorant: new scientific data on ambroxol in the context of the treatment of bronchopulmonary diseases]

BACKGROUND

Ambroxol has been established for decades in the treatment of acute and chronic respiratory diseases. In 2015, the European Medicines Agency reassessed the clinical benefit-risk ratio of the drug.

OBJECTIVE

What new scientific data on ambroxol, which are relevant to the treatment of bronchopulmonary diseases, are available?

METHOD

The review is based on a systematic literature research in medline with the search term "ambroxol" during the publication period 2006-2015. Non-relevant publications were excluded manually.

RESULTS AND CONCLUSIONS

Ambroxol is still intensively researched. The traditional indication as an expectorant is confirmed. But there is also an ever better understanding of the various mechanisms of action as well as the ever more exact modeling of the structures under investigation. New fields of application are conceivable, e. g. in patients with severe pulmonary disease who undergo surgery or who are in intensive care, as an adjuvant in anti-infective therapies, especially in infections with biofilm-producing pathogens, or in rare diseases such as lysosomal storage diseases. However, final evidence of the clinical relevance in these fields of application is still missing.

High-dose Oral Ambroxol for Early Treatment of Pulmonary Acute Respiratory Distress Syndrome: an Exploratory, Randomized, Controlled Pilot Trial

OBJECTIVE

To evaluate efficacy of high-dose oral ambroxol in acute respiratory distress syndrome (ARDS) with respect to ventilator-free days (VFD).

DESIGN

Prospective, randomized, placebo-controlled, blinded pilot trial.

PATIENTS

Sixty-six mechanically ventilated patients (1 month to 12 years) with ARDS who were hand-ventilated for <24 hr before pediatric intensive care unit admission.

INTERVENTIONS

Patients randomized to oral ambroxol (40 mg/kg/day, in four divided doses) (n = 32) or placebo (n = 34) until 10 days, extubation or death whichever is earlier.

MEASUREMENTS AND MAIN RESULTS

Majority (91%) had pneumonia and bronchiolitis. Two study groups were similar in baseline characteristics. Mean partial pressure of arterial oxygen/fraction of inspired oxygen and oxygenation index were >175 and <10, respectively, with no difference in the two study groups. VFD were similar in the two study groups. Overall mortality was 26%. No adverse events were noted with ambroxol.

CONCLUSIONS

Among ventilated pulmonary ARDS patients with oxygenation index of <10, mortality was 26%. Ambroxol did not improve VFD. Study with higher and more frequently administered doses of ambroxol in larger sample is suggested after having generated relevant pharmacokinetic data among critically ill children.

Investigating the Generalizability of Economic Evaluations Conducted in Italy: A Critical Review

OBJECTIVES

To assess the methodological quality of Italian health economic evaluations and their generalizability or transferability to different settings.

METHODS

A literature search was performed on the PubMed search engine to identify trial-based, nonexperimental prospective studies or model-based full economic evaluations carried out in Italy from 1995 to 2013. The studies were randomly assigned to four reviewers who applied a detailed checklist to assess the generalizability and quality of reporting. The review process followed a three-step blinded procedure. The reviewers who carried out the data extraction were blind as to the name of the author(s) of each study. Second, after the first review, articles were reassigned through a second blind randomization to a second reviewer. Finally, any disagreement between the first two reviewers was solved by a senior researcher.

RESULTS

One hundred fifty-one economic evaluations eventually met the inclusion criteria. Over time, we observed an increasing transparency in methods and a greater generalizability of results, along with a wider and more representative sample in trials and a larger adoption of transition-Markov models. However, often context-specific economic evaluations are carried out and not enough effort is made to ensure the transferability of their results to other contexts. In recent studies, cost-effectiveness analyses and the use of incremental cost-effectiveness ratio were preferred.

CONCLUSIONS

Despite a quite positive temporal trend, generalizability of results still appears as an unsolved question, even if some indication of improvement within Italian studies has been observed.

Does ambroxol confer a protective effect on the lungs in patients undergoing cardiac surgery or having lung resection?

A best evidence topic in perioperative care was written according to a structured protocol. The question addressed was 'Does ambroxol confer a protective effect on the lung in patients undergoing cardiac surgery or having lung resection?' A total of 247 papers were found using the reported search, of which 7 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers were tabulated. Several studies indicate that for patients with chronic obstructive pulmonary disease (COPD) who undergo cardiac surgery or upper abdominal surgery, perioperative ambroxol administration is associated with improved pulmonary function and reduced postoperative pulmonary complications (PPCs). In patients with pulmonary lobectomy, large-dose ambroxol treatment (1000 mg/day for 3 days) is correlated with reduced PPCs (6 vs 19%, P = 0.02), decreased postoperative hospital stay (5.6 vs 8.1 days, P = 0.02) and lower postoperative cost (2499 vs 5254 €, P = 0.04) compared with low-dose ambroxol treatment. Ambroxol also has a protective effect on the lungs during extracorporeal bypass, ameliorating inflammatory reaction and oxygen stress and preserving pulmonary surfactant. However, there is no evidence for any advantage of reducing PPCs after extracorporeal circulation. We conclude that perioperative application of ambroxol, a versatile mucoactive drug, particularly in high doses, is associated with lower PPCs, especially in high-risk patients with fundamental lung disease such as COPD. Large doses of ambroxol are correlated with even lower PPCs after lung resection. We recommend that routine intravenous ambroxol should be used in large doses in high-risk patients in the perioperative period to reduce the risk of PPCs.

Biofilm-dependent airway infections: a role for ambroxol?

Biofilms are a key factor in the development of both acute and chronic airway infections. Their relevance is well established in ventilator associated pneumonia, one of the most severe complications in critically ill patients, and in cystic fibrosis, the most common lethal genetic disease in Caucasians. Accumulating evidence suggests that biofilms could have also a role in chronic obstructive pulmonary disease and their involvement in bronchiectasis has been proposed as well. When they grow in biofilms, microorganisms become multidrug-resistant. Therefore the treatment of biofilm-dependent airway infections is problematic. Indeed, it still largely based on measures aiming to prevent the formation of biofilms or remove them once that they are formed. Here we review recent evidence suggesting that the mucokinetic drug ambroxol has specific anti-biofilm properties. We also discuss how additional pharmacological properties of this drug could be beneficial in biofilm-dependent airway infections. Specifically, we review the evidence showing that: 1-ambroxol exerts anti-inflammatory effects by inhibiting at multiple levels the activity of neutrophils, and 2-it improves mucociliary clearance by interfering with the activity of airway epithelium ion channels and transporters including sodium/bicarbonate and sodium/potassium/chloride cotransporters, cystic fibrosis transmembrane conductance regulator and aquaporins. As a whole, the data that we review here suggest that ambroxol could be helpful in biofilm-dependent airway infections. However, considering the limited clinical evidence available up to date, further clinical studies are required to support the use of ambroxol in these diseases.

A thioredoxin reductase and/or thioredoxin system-based mechanism for antioxidant effects of ambroxol

Long-term treatment with ambroxol (ABX), a bronchial expectorant, was found to prevent acute exacerbation of chronic obstructive pulmonary disease (AECOPD). The underlying mechanism remains unclear. To address this, we have investigated the effect of ABX on critical antioxidant proteins thioredoxin (Trx) and thioredoxin reductase (TrxR) that are decreased in patients with AECOPD. Trx, TrxR and NADP(H) form Trx system, which is involved in regulating numerous oxidative stress-related events. In human bronchial epithelial cells, treatment with ABX from 0 to 200 μM gradually increased mRNA and protein levels of TrxR/Trx. At these ABX concentrations, TrxR activity was elevated progressively, whereas Trx activity exhibited a dose-dependent biphasic response, increasing at 50 and 75 μM, but decreasing at ABX over 150 μM. Pre-treatment with 75 μM ABX enhanced the capacity of the cells to eliminate reactive oxygen species, which was largely prevented by knockdown of cytosolic Trx (hTrx1). In a purified system, ABX shortened the initial lag phase during the reduction of insulin disulfide by Trx system. Pre-treatment of NADPH-reduced TrxR with ABX caused a dose- and time-dependent increase in thiolate/selenolate species, i.e. the catalytically active form of TrxR. Kinetic analysis demonstrated that the reduction of H2O2 by TrxR or Trx system were enhanced by 100 or 200 μM ABX. When hTrx1 was mixed with ABX in a molar ratio of 1:1 to 1:100 (which could occur in human plasma), changes in intrinsic Trp fluorescence occurred, and the response of reduced hTrx1 was especially remarkable. These data reveal an ABX-sensing mechanism of TrxR/Trx. We therefore conclude that the antioxidant actions of ABX at physiological concentrations are, at least partially, mediated by TrxR and/or Trx system.

[Fast track in thoracic surgery]

Patients undergoing thoracic surgery are threatened by pulmonary complications such as pneumonia and atelectasis. Age, preoperative FEV(1), operative time and extent of resection are predictors for adverse outcome. Reported morbidity after lung resection is as high as 42% and mortality up to 7%. Fast track in thoracic surgery aims at reducing morbidity and mortality rates after lung resection by introducing specific measures into the pre-, intra- and postoperative periods. Basic fast track elements in thoracic surgery are smoking cessation, preoperative physiotherapy, micronutrient supplementation, high thoracic epidural anesthesia, fluid restriction, early mobilization and enteral feeding. The effectiveness of these individual measures has been proven of value in perioperative care, however, evidence on multimodal therapy regimens in thoracic surgery is limited. In particular it remains to be elucidated which patients should be fast tracked in order to improve outcomes.