key: cord-0731984-ctp55tdf authors: Rubano, Jerry A.; Jasinski, Patrick T.; Rutigliano, Daniel N.; Tassiopoulos, Apostolos K.; Davis, James E.; Beg, Tazeen; Poovathoor, Shaji; Bergese, Sergio D.; Ahmad, Sahar; Jawa, Randeep S.; Vosswinkel, James A.; Talamini, Mark A. title: Tracheobronchial Slough, a Potential Pathology in Endotracheal Tube Obstruction in Patients With Coronavirus Disease 2019 (COVID-19) in the Intensive Care Setting date: 2020-05-20 journal: Ann Surg DOI: 10.1097/sla.0000000000004031 sha: 822e50af557394878f389270d456241f393a24f8 doc_id: 731984 cord_uid: ctp55tdf Treatment of the COVID-19 critically ill patient requires oxygenation and ventilation support for prolonged periods which seem unique for viral pneumonia. The pathophysiology of COVID-19 critical illness is being revealed on a day to day basis at the frontlines of care in the intensive care unit with this new disease. High density consolidations in the bronchial tree and in the pulmonary parenchyma have been described in the advanced phase of the disease. Our team has observed impeded ventilation in intubated patients who are several days into the critical course due to what seems to be tissue sloughing with resultant endotracheal tube obstruction and the consequences thereof. Caregivers need to be aware of this pathological finding, recognize, and to treat this aspect of the COVID-19 critical illness course, which is becoming more prevalent. At our institution, more than 400 patients have been hospitalized thus far for the treatment of COVID-19. Of these more than 25% have required admission to the ICU; the vast majority of those required mechanical ventilation. Although this patient population has met the Berlin Criteria of ARDS,(4) their presentation has not been classic. As noted by multiple sources, there can be dissociation between lung compliance and oxygenation in this patient population.(5,6) Some patients are noted to have a low compliance picture consistent with classic ARDS, while others have high compliance with severely impaired oxygenation and pulmonary findings not typical for ARDS. During their hospitalization, all of the COVID-19 mechanically ventilated patients, whether with classic ARDS or preserved compliance, can Copyright © 2020 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. have substantial variations in their required ventilatory support. P Lei et al. (7) and others (8, 9) have described a CT finding of higher density consolidations in the bronchial tree as well as in the pulmonary parenchyma in the advanced stage of the disease. These consolidations and ground-glass opacities decrease and are absorbed in dissipating stage of the disease. Our first patient in this series, after mechanical ventilation for about 5 days, was noted to have an acute decline in his oxygenation and ventilation. It was felt initially that this was secondary to a pulmonary embolus due to the hypercoagulable nature of COVID-19. However, assessment of his ventilatory parameters raised concern for an acute airway obstruction. Exchange of the ETT revealed that the tube was occluded by a thick plug. Thereafter, with IRB approval, we examined a subset of patients that appeared to have a similar clinical picture in that they appeared to be steadily improving in their required pulmonary support, with a sudden, significant increase in peak airway, plateau and peak inspiratory pressures with inability to adequately oxygenate and ventilate. Partial or complete ETT occlusion was noted to be the culprit in the vast majority of these patients. All COVID-19 mechanically ventilated patients are admitted to one of our hospital's COVID-19 ICUs. Staffing of the COVID-19 ICUs is by a team of board-certified medical or surgical intensivists. Per current staffing and protocol, an intensivist completes rounds daily on each of these critically ill patients. As part of our multi-disciplinary rounds, all arterial blood gas (ABG) results, as well as ventilator settings and ventilator measurements (including plateau airway pressure depending on ventilator model, peak inspiratory pressure (PIP), and exhaled tidal volume) are discussed and addressed. The pulmonary findings seen in this patient population are not classic. Indeed, these patients seem to have a component of ARDS and in many ways also mimic inhalational injury. To help prevent additional lung Copyright © 2020 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. injury, ARDSNet Protocols(4) are followed. All patients have central venous catheters and arterial lines placed for hemodynamic monitoring. Patients with impeded ventilatory status are also monitored with continuous end-tidal carbon dioxide (EtCO2) measurements, when available. Any episode of desaturation or abrupt change in EtCO2 is expeditiously assessed by the team. Initially, the mechanical aspects of the ventilatory circuit are assessed to ensure appropriate set-up. Additionally, suction catheters are passed to assess for plugging and manual ventilation is undertaken to assess resistance. In this subset of patients with confirmed acute occlusion of their ETT, acute elevation in peak airway and peak inspiratory pressure are generally noted in conjunction with desaturation. When ABGs or PIPs were available pre-or post-ETT exchange they were noted to be congruent with this phenomenon, indicating both decreased oxygenation and impeded ventilation. Improvement in PIPs was noted in those patients with a confirmed occluded ETT, by anesthesia, at the time of exchange. Elevated PIPs, with abrupt change were felt to be more predictive of an acute ETT occlusion. In a subset of our COVID-19 mechanically ventilated patients, acute obstruction of the ETT has led to an inability to oxygenate and ventilate. Remarkably, although this patient population meets Berlin Criteria for ARDS, compliance is maintained in many of our patients. In traditional ARDS, both oxygenation and ventilation are impeded with significantly elevated airway pressure with any large tidal volume. Per Berlin Criteria, the severity of ARDS is assessed by a relatively acute onset coupled with specific PaO2/FiO2 ratios. Any PaO2/FiO2 ratio less than 150 is considered severe ARDS. On review of approximately 110 patients in our adult COVID-19 ICUs, 28 patients required an urgent change of their ETT due to a suspected acute occlusion of the ETT (Figure 1) Any sign of obstruction, even partial, should prompt consideration for an ETT tube exchange. We have started to employ single-use endotracheal tube cleanersdevices similar to Fogarty embolectomy cathetersthat allow extraction of inspissated secretions and the like from an ETT. These can be attached to the ETT via Y-connectors, allowing them to remain part of a closed circuit and hence protecting healthcare workers from aerosolization of the virus during tube cleaning. There is a theoretical risk of an ETT occlusion from the plugs and, hence, staff should be ready to re-intubate immediately. Bronchoscopy could also be considered to diagnose the problem but has limited ability to treat without advanced techniques and results in aerosolization. Traditional bronchoscopy would enable one to irrigate and suction out mucus secretions and/or hemorrhage. However, the tenacity of the occlusive material may be unable to be suctioned via a traditional bronchoscope and require further instrumentation for removal. Routine ETT exchanges are being evaluated, as obstruction appears to occur typically around day 7 of intubation. Change of the occluded ETT has resulted in near immediate resolution of ventilation and oxygenation difficulties in a subset of patients, which has culminated in several successful extubations. Another contributing factor may be the use of heat and moisture exchangers (HME), as opposed to heated circuits in many of these patients. While Copyright © 2020 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. the role of HMEs in ETT obstruction is debated, (10) it may be that HMEs in this particular circumstance are not sufficient. A subset of mechanically ventilated COVID-19 patients had sudden pulmonary decompensation due to acute occlusion of the ETT. Clinicians need to be aware of the possibility of this devastating complication and aggressively treat this aspect of the COVID-19 illness. The authors report no disclosures or conflict of interest. Hospitalized Patients with 2019 Novel Coronavirus-Infected Pneumonia in Wuhan, China Severe Outcomes Among Patients with Coronavirus Disease 2019 (COVID-19) -United States Covid-19 in Critically Ill Patients in the Seattle Region -Case Series Acute respiratory distress syndrome: The Berlin definition Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited The -baby lung‖ became an adult Anatomical and functional intrapulmonary shunt in acute respiratory distress syndrome The Progression of Computed Tomographic (CT) Images in Patients with Coronavirus Disease (COVID-19) Pneumonia Time Course of Lung Changes On Chest CT During Recovery From 2019 Novel Coronavirus (COVID-19) Pneumonia. Radiology Radiological findings from 81 patients with COVID-19 pneumonia in Wuhan, China: a descriptive study Heat and moisture exchangers versus heated humidifiers for mechanically ventilated adults and children