A novel, rapid, and effective technique for whole lung lavage in patients with pulmonary alveolar proteinosis and silicosis: retrospective study

BACKGROUND

Pulmonary alveolar proteinosis (PAP) presents a significant challenge due to its progressive and potentially fatal nature. Whole lung lavage (WLL) is a key treatment for primary PAP with respiratory failure. Despite its efficacy, the lack of standardised protocols has led to diverse practice techniques across different institutions. Our study introduces a novel approach, employing a cardiopulmonary bypass (CPB) system for infusing lavage fluid, a method not previously utilised. This paper will share our pioneering experience with this technique at a tertiary referral centre, focusing on its implementation and safety profile.

METHODS

This retrospective study included patients aged ≥ 18 who underwent WLL for PAP or silicosis. Pre-lavage preparations included chest X-rays and pulmonary function tests (PFT). Preprocedural empiric antibiotics were administered. During lavage, warm saline was infused using a CPB, with cycles of normal saline infusion and degassing until fluid clarity was reached. Positioning techniques facilitated saline drainage. The procedure concluded with intravenous furosemide administration.

RESULTS

Fifty-two WLLs were identified between 2010 and 2024; complete data was available for 33 procedures. Of these, 91% were due to PAP, and 9% to silicosis. Almost half of the patients did not require additional WLL, while 43% needed sequential contralateral WLL. Median operative and mechanical ventilation times were 65 [58.5, 67.5] and 118 [97, 195] minutes, respectively. The median length of hospital stay was two days [2, 3]. Although not statistically significant, O2 saturation and a 6-minute walk distance increase were observed after the WLL.

CONCLUSION

This study outlines our novel approach to WLL, which incorporates rapid saline infusion via a CPB system. Our findings indicate reduced procedure time while maintaining safety and efficacy for treating PAP and silicosis. Despite promising results, the retrospective design and small sample size limit generalizability. Further high-quality studies are warranted to validate and refine this technique.

Whole lung and sequential bronchoscopic lavage for pulmonary alveolar proteinosis

PURPOSE OF REVIEW

Pulmonary alveolar proteinosis (PAP) is a diffuse lung disease that results from the accumulation of lipoproteinaceous material in the alveoli due to abnormal surfactant homeostasis. Since its introduction in the 1960s, whole lung lavage (WLL) has been the primary treatment for PAP. This review focuses on WLL, including its technique modifications, and sequential bronchoscopic lavage.

RECENT FINDINGS

Autoimmune PAP, which accounts for the majority of cases, occurs when antigranulocyte-macrophage colony-stimulating factor (GM-CSF) autoantibodies lead to the deficiency of bioavailable GM-CSF. At present, there are no international guidelines or consensus statements for PAP treatment. Traditionally, therapeutic decisions are made based on the severity and type of PAP. Despite emerging data on GM-CSF-based therapies, WLL remains a central component in the therapeutic strategy for PAP.

SUMMARY

Although the technique of WLL has evolved over time, there is still no universally adopted, standardized protocol. However, key periprocedural aspects - such as preprocedural planning, patient evaluation, anesthetic technique, lavage protocol, and postprocedural care - remain essential to ensuring the safety and success of WLL.

Pulmonary alveolar proteinosis in Taiwan

BACKGROUND/PURPOSE

Pulmonary alveolar proteinosis (PAP) is rare disease manifested as alveolar macrophage dysfunction and abnormal accumulation of surfactant protein in the alveoli. In this nationwide, population-based study, we investigated the epidemiology of PAP in Taiwan, and discovered the comorbidities and prognostic factors of PAP.

METHODS

From the National Health Insurance Research Database (NHIRD), we obtained comprehensive information about all patients of PAP in Taiwan between 1995 and 2013. The incidence, baseline characteristics comorbidities, and prognostic factors of PAP were investigated.

RESULTS

The annual incidence rate of PAP was around 0.79 (range: 0.49-1.17) patients per million people after 2000, and the prevalence rate was 7.96 patients per million people by the end of 2013. In total, 276 patients of PAP were identified, including 177 (64%) and 99 (36%) patients with primary and secondary PAP, respectively. The median age of diagnosis was 53.8 years. The median survival was 9.6 years after the initial PAP diagnosis, and the 5-year survival rate was 65.96%. Twenty (7%) patients received whole lung lavage (WLL) within three months after the diagnosis had significantly better survival compared to the others. Multivariable Cox regression analyses showed that elder age, secondary PAP, and malignancy were associated with poorer survival, while WLL within 3 months of diagnosis might greatly improve the survival.

CONCLUSION

We demonstrated the epidemiology of PAP in Taiwan, showing several poor prognostic factors and the potential effectiveness of WLL. Further prospective studies based on registry are warranted to improve the diagnosis and treatment of PAP.

Purinergic signaling during Marek's disease in chickens

Purinergic receptors (PRs) have been reported as potential therapeutic targets for many viral infections including herpesviruses, which urges the investigation into their role in Marek's disease (MD), a herpesvirus induced cancer in chickens that is an important pathogen for the poultry industry. MD is caused by MD virus (MDV) that has a similar viral life cycle as human varicella zoster virus in that it is shed from infected epithelial skin cells and enters the host through the respiratory route. In this report, PR responses during natural MDV infection and disease progression was examined in MD-resistant white Leghorns (WL) and MD-susceptible Pure Columbian (PC) chickens during natural infection. Whole lung lavage cells (WLLC) and liver tissue samples were collected from chickens infected but showing no clinical signs of MD (Infected) or presenting with clinical disease (Diseased). RNA was extracted followed by RT-qPCR analysis with gene specific primers against members of the P1, P2X, and P2Y PR families. Differential expression (p < 0.05) was observed in breed and disease conditions. Some PRs showed tissue specific expression (P1A1, P2X1, and P2X6 in WLLC) whereas others responded to MDV infection only in MD-susceptible (PC) chickens (P1A2A, P2X1, P2X5, P2X7). P2Y PRs had differential expression in both chicken lines in response to MDV infection and MD progression. This study is the first to our knowledge to examine PR responses during MDV infection and disease progression. These results suggest PR signaling may an important area of research for MDV replication and MD.

Autoantibodies in immunodeficiency syndromes: The Janus faces of immune dysregulation

Immunodeficiency syndromes represent a diverse group of inherited and acquired disorders, characterized by a spectrum of clinical manifestations, including recurrent infections, autoimmunity, lymphoproliferation and malignancy. Autoantibodies against various self-antigens reflect the immune dysregulation underlying these disorders, and could contribute to certain clinical findings, such as susceptibility to opportunistic infections, cytopenia of different hematopoietic lineages, and organ-specific autoimmune diseases. The mechanism of autoantibody production in the context of immunodeficiency remains largely unknown but is likely shaped by both intrinsic genetic aberrations and extrinsic exposures to possible infectious agents. These autoantibodies if harbor neutralizing activities and reach certain levels in the circulation, could disrupt the biological functions of their targets, resulting in specific clinical manifestations. Herein, we reviewed the prevalence of autoantibodies against cytokines, hematopoietic cells and organ-specific antigens in immunodeficiency syndromes and examined their associations with certain clinical findings. Moreover, the potential mechanism of autoantibody production was also discussed. These may shed light on the development of mechanism-based therapies to reset the dysregulated immune system in immunodeficient patients.

Efficacy and safety of whole-lung lavage for pulmonary alveolar proteinosis: a protocol for a systematic review and meta-analysis

INTRODUCTION

Pulmonary alveolar proteinosis (PAP) is an ultrarare disorder characterised by the accumulation of alveolar surfactant and the dysfunction of alveolar macrophages that results in hypoxemic respiratory failure. Whole-lung lavage (WLL) is currently the primary therapy for PAP. However, systematic evaluation of the clinical efficacy of WLL is lacking. We aim to perform a systematic review and meta-analysis of existing evidence to support WLL for the clinical treatment of PAP.

METHODS AND ANALYSIS

We will search the PubMed (MEDLINE), Cochrane Library, Embase, Web of Science and Google Scholar databases from inception to December 2021 for observational studies using WLL for the treatment of PAP. Two authors will independently screen the eligible studies, assess the quality of the included papers and extract the required information. Review Manager V.5.4 will be used to perform the meta-analysis. We will evaluate the overall quality of evidence using the Grading of Recommendations, Assessment, Development and Evaluation approach. All steps of this protocol will be performed using the Cochrane Handbook for Preferred Reporting Items for Systematic Review and Meta-analysis statement.

ETHICS AND DISSEMINATION

This systematic review and meta-analysis will be based on published data. Therefore, ethical approval is not required. We will publish our results in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42022306221 (https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022306221).

One-session bilateral sequential whole lung lavage (OSBSWLL) for the management of pulmonary alveolar proteinosis

BACKGROUND

Whole Lung Lavage (WLL) has been an important part in the management of Pulmonary Alveolar Proteinosis (PAP) since it improves radiologic and clinical parameters. Bilateral WLL is usually performed in two sessions on different days. Few case reports have described one-session bilateral sequential lung lavage (OSBSWLL), and none have described ambulatory management (same-day discharge).

METHODS

Demographic characteristics, physiologic parameters, procedure details and outcomes were retrospectively collected on consecutive patients who underwent OSBSWLL for PAP following an ambulatory protocol stablished in our institution.

RESULTS

A total of 13 patients underwent 30 OSBSWLL (61.5% male; mean age 40). The mean SpO2 was 90% (IQR 9) and 94% (IQR 6), before and after OSBSWLL respectively. In 63.3% of cases, patients were discharged home the same day of procedure. Only in two cases (6.6%), patients required post-procedure prolonged mechanical ventilation (> 4 h) due to persistent hypoxia.

CONCLUSIONS

OSBSWLL can be performed with same-day discharge.

Increased Efficacy of Whole Lung Lavage Treatment in Alveolar Proteinosis Using a New Modified Lavage Technique

BACKGROUND

Autoimmune pulmonary alveolar proteinosis is an ultra-rare pulmonary disease. Whole lung lavage (WLL) is considered the gold standard therapy. We report a protocol for a new modified lavage technique (nMLT) in which controlled repetitive manual hyperinflation (MH) and intermittent chest percussion are used to enhance WLL efficacy.

METHODS

We included all subjects with autoimmune pulmonary alveolar proteinosis treated with nMLT between 2013 and 2018. nMLT consisted of repetitive MH with intermittent chest percussion every third wash. We reported: instilled volume, protein concentration, and optical density using spectrophotometry. Pulmonary function (FVC %predicted and DLCO %predicted) at start of nMLT was recorded. Data are displayed as mean (±SD), median [interquartile range], or number (%). Comparisons within individuals were made using Students t test.

RESULTS

We included 11 subjects (64% male) in whom a total of 67 nMLTs were performed. One nMLT consisted of 15 [12-18] washes. Protein removal was 9.80 [7.52-12.66] g per nMLT. After the first, second, and third cycle of 3 washes, 56% [49% to 61%], 81% [77% to 84%], and 91% [88% to 94%] of the final protein yield was removed, respectively. Optical density was measured 116 times and increased from 1.13 (±0.52) to 1.31 (±0.52) after MH (P<0.001).

CONCLUSION

Efficacy of WLL seems to be enhanced by applying MH every 3 washes. Our technique of WLL with nMLT could be used to increase the amount of protein recruited while instilling the lung with the smallest volume of fluid as possible.

Effect of early whole lung lavage at different time-points for promoting the removal of depleted uranium from the lung

PURPOSE

This study compared the effect of whole lung lavage (WLL) at different time-points early after exposure of the respiratory system to insoluble radioactive particles.

MATERIALS AND METHODS

Forty adult beagles were randomized into a control group and the 3-h, 8-h, 24-h, and 48-h lavage groups (n = 8). A canine model of acute lung injury was established by spraying a depleted uranium (DU) suspension using a superfine fiber bronchoscope, at a dose of 20 mg/kg. The lavage groups were subjected to WLL at 3 h, 8 h, 24 h, and 48 h post-DU exposure, while the control group received no treatment after exposure. Measurement of U in serum was performed using inductively coupled plasma mass spectrometry; measurements in the lavage fluid and left lung tissue were performed using inductively coupled plasma atomic emission spectrometry. The color of the lavage fluid was analyzed using colorimetry, and shadow changes in the lung were observed using chest computed tomography (CT).

RESULTS

The lavage groups showed similarly increasing trends for serum U levels from DU exposure to 3 and 7 days after exposure; however, these values were significantly lower than those in the control group (p < .01). The U content in the lavage fluid was significantly higher in the 3-h group than in the 8-h, 24-h, and 48-h groups (p < .01), while that in the 8-h group was markedly higher than those in the 24-h and 48-h groups (p < .05). The average clearance rate of DU in the lungs varied in the range of 0.63‒7.06%. The U content in the left lung tissue of each lavage group was significantly lower than that in the control group (p < .01), while the content in the 8-h, 24-h, and 48-h groups was significantly higher than that in the 3-h group (p < .05). The colorimetric score of the lavage fluid in the 3-h group was significantly lower than those in the 8-h, 24-h, and 48-h groups (p < .05). Chest CT showed different degrees of consolidation and ground glass shadow changes in all groups. The score of the left lung shadow volume in the 3-h group was significantly lower than in the control, 8-h, 24-h, and 48-h groups (p < .01), while the score in the 8-h group was significantly higher than those in the 48-h and control groups (p < .05).

CONCLUSIONS

The best effect of WLL after exposure of the respiratory system to insoluble radioactive particles was achieved at 3 h, followed by 8 h; there was no difference in the effectiveness of lung lavage at 24 h and 48 h.

Efficacy of whole lung lavage in pulmonary alveolar proteinosis: a 20-year experience at a reference center in Thailand

Background

Pulmonary alveolar proteinosis (PAP) is a rare lung syndrome. The current standard treatment is whole lung lavage (WLL). We reviewed PAP cases treated with WLL during a 243-month period. The primary objective was to describe the efficacy of WLL. We compared chest imaging resolution and pulmonary function tests (PaO₂ and DLCO) before the first and after the last WLL. The secondary objectives were to compare mMRC dyspnea scores, other lung function parameters, and complications of WLL.

Methods

We retrospectively reviewed PAP patients from 1 January 2000 to 31 March 2020. Demographic data, pulmonary function tests, and the efficacy of WLL were collected from the electronic medical database and analyzed by descriptive analysis. Differences in data used the student t-test to compare parameters pre- and post-WLL.

Results

A total of 19 PAP patients and 50 WLL procedures were included. Eleven patients (57.9%) were females and the mean age was 51.5±11.7 years. Dyspnea (100%) and cough (94.7%) were the two leading symptoms. The most common indication for WLL was progressive dyspnea. There were significant improvements in SpO₂ from 86% to 94% (P<0.001), PaO₂ from 49.3 to 66.1 (P<0.001), DLCO from 31.8% to 52.5% predicted (P=0.013), and the mMRC dyspnea score from 3 to 2 (P<0.001) without major complications.

Conclusions

WLL is an effective standard treatment for PAP cases. It is safe and can be used as a primary treatment in case of inhaled anti GM-CSF is not available.

Whole-Lung Lavage-a Narrative Review of Anesthetic Management

Pulmonary alveolar proteinosis is a rare disease characterized by progressive accumulation of lipoprotein material in the alveoli as a result of a dysfunction in surfactant clearance. The whole-lung lavage procedure is considered the current standard of care and consists of the sequential lavage of both lungs for mechanical removal of residual material in the alveoli. However, a lack of standardization has resulted in different procedural techniques among institutions. Even though whole-lung lavage is considered to be a safe procedure, unforeseen complications might occur, and proper knowledge of physiologic implications may allow clinicians to establish the appropriate therapy. This review provides an insight into the underlying physiology of the disease, the technical details of the procedure from an anesthesiologist's perspective, and discussion of potential intraoperative complications.

A review of biological effects and treatments of inhaled depleted uranium aerosol

Depleted uranium (DU) is primarily used for DU bombs and DU tanks in the military. Aerosol inhalation is considered the primary route of DU exposure. Although laboratory tests have confirmed that inhalation of DU aerosol can cause lung, kidney, and other organ damage, epidemiological studies have found no conclusive evidence that persons in areas with prolonged exposure to DU-containing bombs are affected. After the body inhaled DU aerosols, we first clear the insoluble DU through whole-lung lavage (WLL). Then we eliminate the soluble uranium by the chelating agent. Besides, reducing DU damage to tissues and cells through drugs is also an important treatment method. In future research, emphasis should be placed on the damage mechanism of DU aerosol, the laboratory and clinical research of DU chelating agents, the research on the combination of DU chelating agent and WLL, and the research and development of new drugs to prevent DU damage.

Alveolar proteinosis due to toxic inhalation at workplace

We report a clinical case of a 39-year old male, without any known previous medical condition but with occupational exposure to paints and dust cement, who presented an autoimmune pulmonary alveolar proteinosis (PAP) triggered by exposure to toxic inhalation at his workplace. PAP is a rare lung disease characterized by intra-alveolar abnormal accumulation of surfactant. The presence of a crazy-paving pattern in high-resolution computed tomography scan brings the suspicion of PAP although histopathology results of bronchoalveolar lavage are always required for its final diagnosis. The autoimmune form of PAP due to toxic inhalation, such as the one here described, is rare and it is usually difficult to establish a causal relationship.

Inhaled granulocyte-macrophage colony stimulating factor for mild-to-moderate autoimmune pulmonary alveolar proteinosis - a six month phase II randomized study with 24 months of follow-up

Background

Treatment of autoimmune pulmonary alveolar proteinosis (aPAP) by inhaled granulocyte-macrophage colony stimulating factor (GM-CSF) is considered safe and effective. Evidence of benefit from GM-CSG inhalation for mild to moderate aPAP patients is limited.

Methods

In this multicenter, randomized, open-labeled clinical trial, 36 aPAP patients with mild to moderate disease severity were randomized into either the GM-CSF treatment group or control group. Inhaled GM-CSF was prescribed for 6 months, and patients received follow-up for another 18 months without treatment. Physiological features of the patients were analyzed.

Results

There were 36 patients (19 in the treatment group, 17 in the control group) included. There were no significant differences in the primary endpoints as measured by the change of alveolar arterial oxygen gradient (A-aDO₂) from the baseline values to the values obtained during treatment or during the following 18-month non-treatment observation period [control group vs. treatment group: 0.51 ± 12.09 mmHg vs. -0.35 ± 13.76 mmHg, p = 0.848 (3 month); 1.85 ± 11.21 mmHg vs. 7.31 ± 8.81 mmHg, p = 0.146 (6 months); 6.05 ± 11.14 mmHg vs. 6.61 ± 10.64 mmHg, p = 0.899 (24 months)]). Percentage of diffusion capacity predicted (DLCO%) and percentage of total lung capacity predicted (TLC%), however, were significantly improved in the treatment group by the end of the study (P = 0.010 and 0.027). St. George Respiratory questionnaire (SGRQ) scores were better after 6 months treatment with GM-CSF compared to the control group, and the benefits of treatment were maintained throughout the observation period. No severe side effects were observed during the study.

Conclusion

Six months of inhaled GM-CSF treatment had no effect on the alveolar–arterial oxygen gradient in patients with mild to moderate pulmonary alveolar proteinosis. There were changes in some clinical or laboratory measures, but no clinically important changes were noted at the end of study. (Clinical Trial Registry: NCT02243228, Registered on September 17, 2014, https://www.clinicaltrials.gov/ct2/show/NCT02243228?term=NCT02243228&draw=2&rank=1)

Respiratory failure in a 28-year-old male

A 28-year-old male was admitted to the intensive care unit (ICU) for hypoxic respiratory failure requiring intubation and ventilation. He had been dyspnoeic for months leading up to admission with acute worsening 2 weeks prior and reported a 6-kg weight loss over the same time. Occasional dark sputum was reported without haemoptysis, wheeze, chest pain, fever or infectious symptoms. In regard to social history, he smoked 10 cigarettes per day at the time of presentation (<10-pack-year history) and occasionally used marijuana. He worked as a soapstone carver daily and did not use any respiratory protection. In addition, the patient had exposure to a tuberculosis contact ∼1 year prior to presentation.

An interesting case of respiratory failure secondary to occupational exposure in a 28-year-old malehttp://bit.ly/2SzR6dK

Pulmonary alveolar proteinosis

PAP is an ultra-rare disease in which surfactant components, that impair gas exchange, accumulate in the alveolae. There are three types of PAP. The most frequent form, primary PAP, includes autoimmune PAP which accounts for over 90% of all PAP, defined by the presence of circulating anti-GM-CSF antibodies. Secondary PAP is mainly due to haematological disease, infections or inhaling toxic substances, while genetic PAP affects almost exclusively children. PAP is suspected if investigation for ILD reveals a crazy-paving pattern on chest CT scan, and is confirmed by a milky looking BAL that gives a positive PAS reaction indicating extracellular proteinaceous material. PAP is now rarely confirmed by surgical lung biopsy. WLL is still the first-line treatment, with an inhaled GM-CSF as second-line treatment. Inhalation has been found to be better than subcutaneous injections. Other treatments, such as rituximab or plasmapheresis, seem to be less efficient or ineffective. The main complications of PAP are due to infections by standard pathogens (Streptococcus, Haemophilus and Enterobacteria) or opportunistic pathogens such as mycobacteria, Nocardia, Actinomyces, Aspergillus or Cryptococcus. The clinical course of PAP is unpredictable and spontaneous improvement can occur. The 5-year actuarial survival rate is 95%.

Whole lung lavage using a rapid infusion system to treat a patient with pulmonary alveolar proteinosis

Whole lung lavage (WLL) is a therapeutic procedure to remove accumulated material by infusing and draining the lungs with lavage fluid. This procedure has been regarded as the current standard of care to treat pulmonary alveolar proteinosis. However, the WLL protocol has not yet been standardized and the technique has been refined and modified a number of times. A rapid infusion system is a device used to infuse blood or other fluids at precise rates and normothermic conditions. This device is not typically used in WLL, which relies on the passive infusion of fluids using the gravitational force. However, in this study we performed WLL using a rapid infusion system, since we aimed to take advantage of its shorter operation time and greater degree of control over fluid volume and temperature. The patient’s symptoms improved without the occurrence of any complications.

What have we learned in interventional pulmonology in the past decade?

Background/aim

The increasing number of lung diseases and particularly pulmonary malignancies has intensified the need for diverse interventions in the field of interventional pulmonology. In recent years we have seen many new developments and expanding applications in the field of interventional pulmonology. This has resulted in an increased number and variety of performed procedures and differing approaches. The purpose of the present study is to provide information on patient characteristics, range of interventions, complication rates, and the evolving approach of an experienced center for interventional pulmonology.

Materials and methods

We retrospectively examined the records of 1307 patients who underwent a total of 2029 interventional procedures in our interventional pulmonology department between January 2008 and December 2017.

Results

About half of the interventional procedures (47.2%) were performed on patients with airway stenosis due to malignant disease. Among patients with benign airway stenosis, the most frequent reason for intervention was postintubation tracheal stenosis. The number of patients who developed complications was 81 (6.2%), and the most common complication was hemorrhage (n = 31, 2.99%); 94.9% (n = 1240) of interventional procedures were performed under general anesthesia, without complications or deaths associated with anesthesia. Only one death (0.076%) occurred in the perioperative period. A total of 18 patients (1.38%) died in the 30-day perioperative and postoperative period. None of the patients with benign airway stenosis died.

Conclusion

Interventional bronchoscopy is an invasive but considerably safe and efficient procedure for selected cases and effective treatment modality for airway obstructions, massive hemoptysis, and foreign body aspiration. Interventional pulmonology is a field of pulmonary medicine that needs effort to progress and provide an opportunity to witness relevant developments, and increase the number of competent physicians and centers.

Novel method of noninvasive ventilation supported therapeutic lavage in pulmonary alveolar proteinosis proves to relieve dyspnea, normalize pulmonary function test results and recover exercise capacity: a short communication

Whole lung lavage (WLL) under general anesthesia with a double-lumen endobronchial intubation has remained standard treatment option for pulmonary alveolar proteinosis (PAP) for over fifty years now. To the best of our knowledge, this is the first description of noninvasive ventilation (NIV) as an innovative alternative, which enables safe and effective treatment. NIV support enabled cost-effective lavage of the most affected segments and resulted in restoration and long-term maintenance of exercise capacity and diffusion, without WLL related hypoxaemia, volume overload, intubation, or mechanical ventilation related complications. The study presents all details of performed procedure, including anesthesia, NIV technique and bronchoscopy, therefore this may be easily implemented into clinical practice at other centers conducting PAP treatment. We assume that presented technique of therapeutic lung lavage (TLL) with NIV support may be considered a novel PAP treatment method, however, target population who will benefit the most from such therapy modification must be assessed in large scale prospective trials.

Pulmonary alveolar proteinosis in adults: pathophysiology and clinical approach

Pulmonary alveolar proteinosis (PAP) is a diffuse lung disease that results from the accumulation of lipoproteinaceous material in the alveoli and alveolar macrophages due to abnormal surfactant homoeostasis. Identification of the granulocyte-macrophage colony-stimulating factor (GM-CSF) as an indispensable mediator of macrophage maturation and surfactant catabolism was the key discovery leading to the current understanding of the pathogenesis of most forms of PAP. Impaired GM-CSF bioavailability due to anti-GM-CSF autoimmunity is the cause of approximately 90% of adult PAP cases. Abnormal macrophage function due to endogenous or exogenous triggers, GM-CSF receptor defects, and other genetic abnormalities of surfactant production account for the remainder of causes. The usual physiological consequence of PAP is impairment of gas exchange, which can lead to dyspnoea, hypoxaemia, or even respiratory failure and death. Pulmonary fibrosis occurs occasionally in patients with PAP. For patients with moderate to severe disease, whole lung lavage is still the first-line treatment of choice. Supplemental GM-CSF is also useful, but details about indications, choice of agent, and dosing remain unclear. Other therapies, including rituximab, plasmapheresis, and lung transplantation have been described but should be reserved for refractory cases.

Whole lung lavage-technical details, challenges and management of complications

Pulmonary alveolar proteinosis (PAP) is a rare disease characterized by alveolar accumulation of surfactant material with resulting hypoxemia and reduced lung function. Whole lung lavage (WLL) to physically remove the proteinaceous material from the affected lung is the standard treatment. Since its original description in 1964, there have been increasing numbers of WLL procedures done worldwide and the technique has been variously refined and modified. When done in experienced centers, WLL provides long lasting benefit in the majority of patients. It is considered safe and effective. There are no guidelines standardizing the procedure. Our preferred method is to lavage one lung at a time, with the patient supine, filling to functional residual capacity (FRC) and repeating cycles of drainage and instillation with chest percussion until the effluent is clear. The aim of this article is to provide a detailed description of the technique, equipment needed and logistic considerations as well as providing a physiologic rationale for each step of WLL. We will also review the available data concerning variations of the technique described in the literature.