key: cord-0687370-om2gpqur
authors: Saha, Biplab K.; Chenna, Praveen
title: Risk of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) transmission during bronchoscopy in the intensive care unit
date: 2021-08-13
journal: Respirology
DOI: 10.1111/resp.14131
sha: 20cd7ee7f8933560f886a23fe88967ff1adbc135
doc_id: 687370
cord_uid: om2gpqur

nan

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel coronavirus responsible for the ongoing coronavirus disease 2019 (COVID-19) pandemic. Acute respiratory distress syndrome due to SARS-CoV-2 pneumonia is the primary cause of mortality in patients with COVID-19. Approximately 15% of hospitalized patients with COVID-19 require intensive care unit (ICU) admission for mechanical ventilation.

Bronchoscopy is a minimally invasive procedure often performed in the ICU for a number of diagnostic and therapeutic indications. There are several reasons why a bronchoscopic evaluation may be crucial for patients with COVID-19: (1) some patients might have a false negative PCR on nasopharyngeal (NP) swab for SARS-CoV-2 and mislabelling a patient would be important for epidemiologic and infection control purposes, (2) blockage of airways by mucus plugs is a common complication of COVID-19 and associated with worsening hypoxia and (3) identification of secondary bacterial or fungal superinfection is critical, as a delay in appropriate antimicrobial therapy is associated with significantly worse outcomes.

However, due to the increased risk of aerosol generation containing SARS-CoV-2 particles during bronchoscopy, occupational transmission of COVID-19 among healthcare workers (HCWs) has been a major concern. Moreover, the risk of viral transmission during bronchoscopy may also be accentuated by the close proximity of the bronchoscopist and the duration of the procedure. As critically ill COVID-19 patients have a higher viral load in their airways than patients with mild sickness, the risk could be greater. As a result, most societal guidelines at the beginning of the pandemic cautioned against routine bronchoscopy in patients with COVID-19 pneumonia. Nonetheless, this is based on expert opinion, and data to support this notion are scarce.

Several recently published cohort studies (Table 1) have assessed the risk of contracting COVID-19 during bronchoscopy among bronchoscopists and other bedside HCWs in mechanically ventilated ICU patients. These studies have included more than 650 patients who underwent approximately 1200 bronchoscopic procedures. When the exact number of bronchoscopists were specified, 60 bronchoscopists performed a total of 1008 procedures (average of 16.8 procedures). [1] [2] [3] [4] [5] [6] The number of bronchoscopies performed by individual operators ranged between 14 and 42. Both attending and trainee physicians performed the bronchoscopies. 2, 3 The bronchoscopies were performed between 1 and 16 days after the institution of mechanical ventilation. One study specified the duration of the bronchoscopy as being less than 10 min. 1 No significant difference in the perceived level of difficulty was reported based on the experience or training of the operator. 3 Among the 60 bronchoscopists, only two were infected by SARS-CoV-2. No infections were reported among bedside nurses, respiratory therapists or technicians. One bronchoscopist was acutely infected during the second week of the study, requiring replacement. 1 The other operator spent 9 weeks in the ICU and could have contracted the infection at times other than the bronchoscopy. 3 These data are intriguing because the transmission rate of SARS-CoV-2 among HCWs has been reported to be much higher. For example, transmission risk among HCWs was as high as 18% in England and 7.1% in Turkey. In the United States, a tertiary care centre reported a seropositivity of 4.1% among HCWs.

There was significant heterogeneity among studies regarding methods used to identify HCWs who contracted COVID-19 during bronchoscopy. These modalities included (a) clinical observation, (b) clinical observation followed by molecular testing by nucleic acid amplification (NAA) testing if symptoms emerged, (c) serologic testing and (d) a combination of both NAA and serologic testing. Mehta et al. reported clinical surveillance followed by real-time PCR (RT-PCR) of the NP specimen if the HCW became symptomatic. 5 In contrast, Baron et al. performed serologic testing for at-risk individuals. 6 Chang et al. primarily used RT-PCR, whereas Gao et al. used both RT-PCR and serologic testing. 2,3 Some authors reported a positive diagnosis by non-specified test(s). 4 The follow-up period also varied. Most studies did not specify the exact follow-up period. One study 2 followed up atrisk individuals for 2 weeks after the last bronchoscopy, and two others reported following for the duration of the study. 3, 5 Bronchoscopy was performed following the general guideline provided by the World Health Organization (WHO), Centers for Disease Control and Prevention (CDC) and other professional societies. Flexible bronchoscopy was the preferred modality, and all studies reported using a disposable bronchoscope. Bruyneel infected. 4 Nearly all bronchoscopies were performed in negative pressure rooms. Personal protective equipment (PPE) was used universally across the studies. PPE included respirator masks (N95, filtering face piece level 2 [FFP2] and P100), eyeglasses or face shields, hair covering, gown, gloves and shoe covering. In one study, the bronchoscopists used personal powered air-purifying respirator. 4 The personnel used for the actual bronchoscopy procedures varied among research teams. Four groups reported one bronchoscopist performing the procedure, 2,4-6 whereas two reports described a secondary bronchoscopist being present in the room. 1, 3 The secondary bronchoscopist was responsible for ventilator management during the bronchoscopy. In three studies, no other HCWs were present inside the room during bronchoscopy (the nurse was available outside the room). [1] [2] [3] Bronchoscopy was performed in both supine and prone patients without changing positions. Preoxygenation with 100% oxygen (between 2 and 20 min) was undertaken in two studies. 2,5 Torrego et al. titrated the FiO 2 to obtain an SpO 2 between 95% and 98%. 1 Apnoeic bronchoscopy was performed in two studies. 2, 5 The bronchoscopy was interrupted if the oxygen saturation dropped below 90%. Three papers reported disconnecting the ventilator from the endotracheal tube during insertion and withdrawal of the bronchoscope, but mechanical ventilation was continued during bronchoscopy. 1,3,7 Neuromuscular blockers were generally used to prevent cough, which would further increase the risk of aerosolization.

The current data are limited to assess the risk of SARS-CoV-2 transmission during bronchoscopy accurately. Still, overall, the risk appears to be low when recommended precautions are followed, and the HCWs use appropriate PPE. Until more data are available, the use of a disposable bronchoscope is prudent. We advocate for bronchoscopic evaluation when clinically indicated in mechanically ventilated patients with COVID-19.

KEYWORDS bronchoscopy, COVID-19, healthcare worker, ICU, SARS-CoV-2, transmission risk

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Bronchoscopy in COVID-19 intensive care unit patients

Bronchoscopy in COVID19 ARDS patients on mechanical ventilation -a prospective study. medRxiv

Bronchoalveolar lavage in patients with COVID-19 with invasive mechanical ventilation for acute respiratory distress syndrome

Safety, diagnostic, and therapeutic value of flexible bronchoscopy in critically ill COVID-19 patients

Risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission during bronchoscopy in the intensive care unit