Use of venovenous (VV) extracorporeal membrane oxygenation (ECMO) in near-fatal asthma: a case series

Introduction

Status asthmaticus (SA) and near-fatal asthma (NFA) are life-threatening conditions that continue to present a management challenge for physicians. Extracorporeal Membrane Oxygenation (ECMO) has been employed as a last resort in treating these patients.

Case presentation

We described six patients who were admitted to the ICU for NFA and received ECMO treatment at a high-complexity institution in Cali, Colombia, between 2015 and 2019. All patients are registered in the ELSO registry. Baseline patient characteristics, arterial blood gases (ABG), ventilatory parameters, and complications were collected as specified in the ELSO registry form. Efficacy was analyzed in terms of the improvement in respiratory acidosis, the number of ventilator-free days (VFD), and a reduction in mechanical power (MP). MP, which refers to the energy associated with the mechanical forces involved in breathing and the functioning of the respiratory system, was calculated using a mathematical formula. Safety was evaluated based on the incidence of complications. After 12 hours of ECMO, we achieved a correction of respiratory acidosis, a significant decrease in all ventilatory parameters, and a reduction in MP ranging from 52.8% to 89%. There was one mortality. Among the five surviving patients, all except one, who required a tracheostomy, had a high VFD score, with a mode of 26 days, demonstrating a reduction in ventilation time.

Conclusion

Further randomized controlled trials are needed to fully understand the efficacy and safety profiles of ECMO in SA/NFA. MP is being widely used to achieve safer ventilation, and although more data is required, it appears to be a promising option for evaluating the risk of developing VILI and the success of the therapy.

First Lung Transplantation in Jehovah's Witness Patient in Latin America

Lung transplantation is a life-saving alternative for patients with end-stage lung disease. The procedure itself has a high risk of bleeding. Jehovah’s Witness patients refuse to accept blood products due to religious beliefs. A 48-year-old Jehovah’s Witness woman presented with an 8-year history of cough, dyspnea along with progressive worsening of her functional class and quality of life. A diagnosis of autoimmune interstitial lung disease was made, for which cyclophosphamide was administered without improvement of symptoms, and the patient was accepted as a transplant candidate. Transplantation was performed without complications, nor blood products requirement, intraoperative cell salvage was performed, and pharmacological agents were used preoperatively for bleeding prevention. The patient only developed anemia after administration of immunosuppressor therapy, which was treated with erythropoietin in the outpatient setting.

Acute pneumonitis and diffuse alveolar hemorrhage secondary to silicone embolism: A case report

RATIONALE

Polydimethylsiloxane, commonly referred as silicone, is an inert liquid compound used in esthetic procedures due to its durability and thermal stability, yet the application of non-pure silicone generates risks. One of the complications is systemic embolism syndrome which is presents with fever, hypoxemia, and progression to respiratory failure, diffuse alveolar damage and alveolar hemorrhage, as well as neurological alterations in one-third of the cases. Management is strictly supportive. We present the case of acute pneumonitis with alveolar hemorrhage after silicone injection.

PATIENT CONCERNS

25-year-old transsexual man, who consulted 48 hours after liquid silicone injection in the buttocks and trochanteric area, with progressive dyspnea and chest tightness, with rapid progression to respiratory failure.

DIAGNOSIS

Clinical diagnosis of silicone embolism was made. Chest x-ray and CT angiography showed diffuse alveolar infiltrates and pleural effusion without evidence of acute venous thromboembolism. Bronchoscopy plus bronchoalveolar lavage showed hemorrhagic fluid, 60% macrophages with hemosiderin in cytology and negative cultures.

INTERVENTION

Sedation, relaxation, pronation, and protective ventilation were implemented until hemodynamic stabilization; as well as IV steroids and antibiotics.

OUTCOMES

Clinical progress was slow towards improvement with resolution of radiological or physical abnormalities. Despite severity, the patient improved satisfactorily without late sequelae.

LESSONS

Silicone injection can trigger phenomena similar to that seen in fat embolism causing inflammation and immune response activation that lead to alveolar hemorrhage, diffuse alveolar damage, and acute respiratory distress syndrome. We reported pulmonary complications related to the illegal use of injected silicone for esthetic procedures.

Unsuspected foreign-body aspiration in adult patient with status asthmaticus: Case report

Introduction

Accidental foreign body aspiration can cause severe damage to the airway and threaten the patient's life. This situation requires multidisciplinary and systematic approach from the medical and surgical team, in order to achieve complete resolution maintaining airway permeability.

Presentation of case

This is a 49 y/o man who presented with a severe asthma attack, in whom an unsuspected foreign body in the inferior airway was diagnosed, which was possibly the result of aspiration during the initial emergency care, causing worsening of the already critical condition.

Discussion

We described the clinical course, radiologic and endoscopic findings, and outcome of the patient, highlighting the importance of considering the possibility of a foreign body in the airway, when there is no improvement in refractory status asthmaticus. This is particularly important in a university hospital. Moreover, the implementation of checklists when invasive procedures are performed can avoid loss of material, preventing iatrogenic aspiration events.

Conclusion

Foreign body aspirations may remain undetected due to lack of suspicion, especially in adults, in whom they can cause chronic symptoms, or worsen chronic respiratory conditions turning them into more complex diseases. This cause must be considered in the differential diagnosis of refractory status asthmaticus.

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Accidental foreign body aspiration can cause severe damage to the airway.

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This situation can threaten the patient's life.

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Requires multidisciplinary and systematic approach from the medical and surgery team.

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The goal is to achieve complete resolution maintaining airway permeability.

Microcirculatory dysfunction and dead-space ventilation in early ARDS: a hypothesis-generating observational study

BACKGROUND

Ventilation/perfusion inequalities impair gas exchange in acute respiratory distress syndrome (ARDS). Although increased dead-space ventilation (V_D/V_T) has been described in ARDS, its mechanism is not clearly understood. We sought to evaluate the relationships between dynamic variations in V_D/V_T and extra-pulmonary microcirculatory blood flow detected at sublingual mucosa hypothesizing that an altered microcirculation, which is a generalized phenomenon during severe inflammatory conditions, could influence ventilation/perfusion mismatching manifested by increases in V_D/V_T fraction during early stages of ARDS.

METHODS

Forty-two consecutive patients with early moderate and severe ARDS were included. PEEP was set targeting the best respiratory-system compliance after a PEEP-decremental recruitment maneuver. After 60 min of stabilization, hemodynamics and respiratory mechanics were recorded and blood gases collected. V_D/V_T was calculated from the CO₂ production ([Formula: see text]) and CO₂ exhaled fraction ([Formula: see text]) measurements by volumetric capnography. Sublingual microcirculatory images were simultaneously acquired using a sidestream dark-field device for an ulterior blinded semi-quantitative analysis. All measurements were repeated 24 h after.

RESULTS

Percentage of small vessels perfused (PPV) and microcirculatory flow index (MFI) were inverse and significantly related to V_D/V_T at baseline (Spearman's rho = - 0.76 and - 0.63, p < 0.001; R² = 0.63, and 0.48, p < 0.001, respectively) and 24 h after (Spearman's rho = - 0.71, and - 0.65; p < 0.001; R² = 0.66 and 0.60, p < 0.001, respectively). Other respiratory, macro-hemodynamic and oxygenation parameters did not correlate with V_D/V_T. Variations in PPV between baseline and 24 h were inverse and significantly related to simultaneous changes in V_D/V_T (Spearman's rho = - 0.66, p < 0.001; R² = 0.67, p < 0.001).

CONCLUSION

Increased heterogeneity of microcirculatory blood flow evaluated at sublingual mucosa seems to be related to increases in V_D/V_T, while respiratory mechanics and oxygenation parameters do not. Whether there is a cause-effect relationship between microcirculatory dysfunction and dead-space ventilation in ARDS should be addressed in future research.