Liquid fluorocarbon lavage to clear thrombus from the distal airways after severe pulmonary hemorrhage requiring extracorporeal life support (ECLS).

UNLABELLED: Massive pulmonary hemorrhage can pose a significant therapeutic challenge. Traditional methods of airway clearance using saline lavage and direct thrombus removal via bronchoscopy have limited ability to retrieve thrombi from deep airways. We report a patient on extracorporeal life support with massive pulmonary hemorrhage resulting in extensive alveolar and airway thrombus extending well beyond the proximal airways and the novel use of perfluorodecalin lavage to facilitate airway clearance and lung recruitment. CLINICAL TRIAL REGISTRATION: None.

Introduction

Conventional approaches to treating pulmonary hemorrhage rely on sustained positive pressure ventilation to tamponade bleeding, with eventual expectoration and absorption of coagulated blood once the acute hemorrhage has resolved. In cases of severe pulmonary hemorrhage with significant compromise of oxygenation and ventilation, extracorporeal life support (ECLS) can be used to provide time for lung recovery. This therapy is complicated, however, by the need for anticoagulation. After bleeding has stopped, bronchoscopy is the primary therapeutic option for reopening obstructed airways, though its utility is largely limited to the proximal airways, where suction and biopsy forceps can be used to manually retrieve clot [1,2]. We describe the use of perfluorodecalin (PFD) lavage to facilitate airway clearance and lung recruitment in the setting of pulmonary hemorrhage.

Case

A previously healthy 17 year-old female presented with a 5 day history of fevers, chills, cough, myalgia and shortness of breath. She was treated for community-acquired pneumonia but had substantial increase in her oxygen requirements resulting in transfer to the PICU and mechanical ventilation. Placement of a pigtail catheter for pneumothorax was complicated by the development of hemothorax, pulmonary hemorrhage and marked hemodynamic instability. On hospital day #10 she was placed on veno-arterial ECLS.

Chest CT demonstrated fluid-filled airways with complete opacification of both lungs and bronchoscopy revealed thrombus occluding both mainstem bronchi. Sequential attempts at saline lavage to clear these thrombi were minimally successful. The patient's inability to wean from ECLS in the setting of her lung disease prompted the care team to explore less conventional modalities of pulmonary lavage. PFD (OriGen Biomedical, Inc, Austin, TX, USA) was obtained on a compassionate use basis and several aliquots were used to lavage the distal airways of the left lung. Subsequently, the patient was able to cough up some clot debris. Based on the relative success of these small-volume lavages, 250 mL, or approximately 4 mL/kg of PFD was gradually introduced to the left lung over approximately 4 h under bagged pressures of 20/10 mmHg. The patient was then placed on pressure control mechanical ventilation, 20/10 mmHg, overnight. Repeat bronchoscopy the following day demonstrated soft thrombus in the main trachea just distal to the endotracheal tube that had apparently been softened and buoyed up by the PFD. Clot was removed over approximately 4 h with simple suctioning until only clear liquid could be aspirated. A short period of high-frequency oscillatory ventilation was used to optimize recruitment, with the subsequent chest xray demonstrating significant recruitment of the bilateral upper lobes and left lower lobe far beyond the extent to which bronchoscopy can visualize (Fig. 1). The patient's primary disease process prevented further weaning from ECLS and she eventually received a double lung transplant, with the explanted lung revealing extensive necrosis and pneumonia attributed to Staphylococcus aureus.

Fig. 1

Chest X-rays obtained prior to pulmonary lavage with PFD (A) and following suctioning of PFD, thrombus and approximately 24 h of recruitment with high-frequency oscillatory ventilation (B). There is interval improvement in aeration and new air bronchograms consistent with clot removal. PFD, perfluorodecalin.

Discussion

Perfluorocarbons have been examined for a variety of potential pulmonary applications, including tidal liquid ventilation, partial liquid ventilation, and as lavage solutions [3,4]. PFD also holds unique potential in airway lavage and alveolar recruitment in the setting of pulmonary hemorrhage. The density of human clot has been reported as (1.08 ± 0.02) x103 kg/m3, which is slightly greater than aqueous 0.9% NaCl, which has a density of 1.00 × 103 kg/m3 at 37 °C [5,6]. In contrast, the density of PFD is 1.93 × 103 kg/m3, allowing it to buoy thrombus to the proximal airways where it can be retrieved via bronchoscopy [7]. Alveolar surface phospholipids are inhibited by the presence of fibrin, thereby raising the surface tension and promoting alveolar derecruitment [8]. The addition of small volumes of liquid fluorocarbon has been shown to significantly decrease the magnitude of pressure required to recruit alveoli [9,10]. This impact is theorized to stem from the positive spreading coefficient of liquid fluorocarbons relative to surfactant, particularly at the alveolar septal crests [10,11].

Once sufficient lung function has recovered, PFD can be removed via direct suction or allowed to passively evaporate. Systemic absorption of PFD has not been reported, though patients treated with perflurbron, a comparable liquid fluorocarbon, demonstrate small but quantifiable serum levels of the substance following instillation in the lungs [12]. While promising for acute therapies, it must be noted that robust long-term data on the effects of perfluorocarbon lavage and ventilation do not exist, though existing case reports of patients evaluated 9–12 years following treatment make no mention of any detrimental impact [13,14]. The use of PFD lavage in this case demonstrates the potential utility of this unique medium for concomitant ventilation and lavage in patients suffering from severe pulmonary hemorrhage with distal airway obstruction resulting from in situ thrombus.

Funding source

No external funding was secured for this study.

Financial disclosure

The authors have no financial relationships relevant to this article to disclose.

Conflict of interest

The authors have no conflicts of interest to disclose.