Airway management with need for airway separation/isolation and indication for OLV represented a challenge within a challenge during COVID-19 outbreak. Intubation and airway management have been ranked within the most significant AGPs [2], and techniques for lung isolation/separation may represent advanced airway management procedures exposing HCPs to higher risk [6, 8].
Data from our survey partially reflect these considerations and the implications for specific surgical area, including how the COVID-19 pandemic induced a change in routine clinical practice. The survey indicates that in Italy there was a 61% global reduction for thoracic surgical activity reflecting the patients overflow, the PPE shortage and—probably—a certain difficulty in maintaining the “elective” oncologic surgical activity despite national healthcare system indications.
Lack of patients’ screening, COVID-free hospitals, and separation of infected/clear pathways in COVID-hospitals had also a major role [9].
Eighty-three percent of responders declared some change in their routine clinical practice in choice of endotracheal tube (DLT vs SLT + BB); interestingly, DLT was chosen in 53% of cases; in the assumption, it was considered at lower infection risk if compared to SLT placement followed by use of BB or placement of a DLT over an AEC. These opportunities are considered in different thoracic anesthesia guidelines released during the COVID-19 outbreak [6, 8]; nevertheless, no evidence supports one choice against the other. Theoretically, risk of aerosolization, viral spread, and infection is directly related to airway manipulation and instrumentation, which is intuitively increased if using a BB or a tube exchange procedure. Moreover, in the vast majority of cases, BBs require a bronchoscopic check of the correct positioning, given also the well-known tendency of these devices to dislocation [10]. Despite dedicated ports on airway connectors, with differently effective sealing options, disconnections and bronchoscopy could expose the operator to biological risk. Also, BBs require a certain expertise, and it has been found that at least 15 procedures are necessary to develop a satisfactory and safe level of confidence with these devices [11]. Developing such a skill during a COVID-19 pandemic is someway dangerous, so we strongly discourage adoption of this technique for non-skilled users. On the other hand, use of a DLT might be more challenging in some patients (13.6% difficult intubation, 9% difficult mask ventilation, 2% both in a thoracic anesthesia series of 763 patients) [12], with implications on risk of aerosolization and clinical complications for the patient associated with repeated laryngoscopic attempts [13]. Italian data from a previous survey confirm this observation [14] reporting regular use of BBs in only by 5% of cases [15].
During COVID-19 pandemic, in the present survey, we thus registered a four-time increase of BBs use in thoracic anesthesia practice. We might hypothesize that this behavior reflects the perceived advantage of no need to disconnect the patient from the mechanical ventilator for lung exclusion, with consequent reduction of potential aerosolization. This hypothesis might be confirmed also by the observation that 67% of responders used a HEPA filter at the proximal end of the DLT lumen ventilating the nondependent lung (thus disconnected during OLV). There is no evidence-based data for this technique; despite, it is suggested in COVID-19-related airway management [6, 8] and in different case reports [5, 16, 17].
In lack of specific evidence, we believe that the use of HEPA filters on the DLT lumen of the collapsed lung should be encouraged to minimize aerosolization and infection risk. Similarly, a HEPA filter may be added on the DLT yet during the intubation phase aimed to minimize the risk of aerosolization due to coughing or gagging during intubation attempts but adding a HEPA filter might impede swift airway management, unbalancing the DLT during intubation and complicating the stylet removal during DLT advancement. Such a recommendation was well perceived in our sample and adopted by 97% of responders, despite a reported practical difficulty such as avoiding manual ventilation. Thirty-nine percent of responders did not use a HEPA filter during intubation.
Similarly, VLS-SS was suggested in the same guidelines for airway management in COVID-19 patients RSII [7, 18] including specific thoracic anesthesia recommendations [6, 8]. Furthermore, VLS increases the success rate at first attempt for DLT intubation as reported in a recent meta-analysis by Liu et al. [19]. As from our survey, 97% of responders used a VLS.
Similar changes occurred also for other airway maneuvers: in case of tracheal tube change using an AEC, most of anesthetists reported to adopt specific behaviors and habits compared to the pre-COVID-19 era, with special emphasis on generous upper airways suction, insurance of a deep neuromuscular blockade, generous and rigorous pre-oxygenation, performance of the maneuver with VLS and with preparedness of a backup plan in case of failure.
Use of bronchoscope has been one of the most debated issues during the COVID-19 pandemic, given its potential for aerosolization, especially in the awake and spontaneously breathing patient.
As a matter of fact, use of bronchoscope is a mandatory skill and unavoidable procedure in thoracic anesthesia practice [20]. Recommendations from the Italian Intersociety Consensus on Perioperative Anesthesia Care in Thoracic surgery consider fiberoptic assistance strongly recommended [21]. This indication is someway reflected in our survey: 39% of participants considered mandatory the bronchoscopic check of the used OLV device. Out of any doubt, this data suggests a reduction of use of bronchoscope during the outbreak, relying on the assumption that in experts’ hands the use of bronchoscope could be safely reduced [22]. As a side remark, 50% of our responders used a disposable bronchoscope, and 25% switched from reusable to disposable because of the COVID-19 pandemic, reflecting a growing trend and a different approach to cost-effectiveness of disposable devices [23].
Interestingly, in our sample, whenever seemed unavoidable, awake intubation was performed in 47% of cases with a bronchoscope, whereas 53% of responders used an awake technique with a VLS using either SLT and DLT.
In a Chinese case series during COVID-19 outbreak, the VLS was faster and less skill-requiring than bronchoscope in case of spontaneous breathing intubation [24]. We believe that our data reflect on one hand the familiarity with awake bronchoscopic intubation, and on the other the high skills and confidence of surveyed users, given their daily practice in the specialist field of thoracic anesthesia, including experience with awake VLS intubation.
Questions for the last domain, regarding three specific airway techniques/devices, indicated that 50% of a sample of expert anesthetists was familiar and used the VivaSight-DLT, or barrier enclosure systems such as aerosol boxes and drapes. The VivaSight-DL was perceived as more comfortable in respect of conventional techniques for intubation, reduced need for circuit disconnections and bronchoscopy thanks to the built-in camera. Interestingly, the VivaSight-DLT was listed between desirable items by the thoracic anesthetists enrolled in our survey.
Aerosol box, first described by Canelli and colleagues [25], had a fast-worldwide diffusion due to pricing and availability in face of PPE shortage. Many concerns exist, with special reference to ability of these devices to protect against large droplets but not against aerosols (including concerns for post-procedural cleaning) [26], and our data also add further concerns regarding comfort, ergonomics, and maneuverability especially during advanced/difficult airway management and use of bronchoscope. Similar conclusions might be drawn for plastic covers and drapes [27], which share same limitations as the aerosol boxes plus the superior risk of “secondary aerosolization” upon removal. Despite their large diffusion, also in Italian hospitals and with different variations, we believe that the use of barrier enclosure systems should never substitute an adequate PPE setting, and their use should be prudently avoided until when evidence will support their use.
Only 47% of responders subjectively indicating that their hospitals reported adequate PPE supplies, despite the higher-risk setting represented by thoracic surgery compared to other surgical specialties. This need was clearly addressed in our survey, with 5% of reports indicating scarce supply of PPE, and the perceived need of importance of this level of protection, as indicated in the desirable items section. Not a case, our survey underlines that 6 out 10 Italian hospitals do not recognize thoracic anesthesia as a high-risk specialty in terms of exposure to virus diffusion and risk of infection during airway management.
This survey has several limitations: the response rate was 64%, meaning that we might have missed significant responses; moreover, the sample size was very limited, given that the chosen sample consisted of 56 anesthetists, as they were representatives of the major Italian thoracic surgery centers. Aware of the limits of the real national representativeness of such data, this survey allowed us to promptly photograph the pandemic picture during the early days of the outbreak, at least in high volume centers.
In conclusion, during the COVID-19 outbreak in Italy, DLT were mostly used devices to achieve lung separation/isolation and OLV, but with increased use of BBs if compared with pre-pandemic era. Videolaryngoscopes remain confirmed as preferred and preferable devices for intubation.
Bronchoscopy, though perceived as a high-risk procedure in terms of viral spreading potential, was still largely used either for tube position check or for BBs placement, with a certain trend in reduced use thanks to alternative devices and techniques. A certain diffusion of new devices, such as the VivaSight-DLT and barrier enclosure systems, was observed. The first was highly appreciated and largely used, whereas the latter were mostly deemed uncomfortable and limiting airway maneuvers. Adoption of barrier enclosure systems was also indicated as a consequence to a certain shortage or scarcity in PPE availability, whose importance was largely underlined by the survey responders.
In light of these data, we underline the specificity of thoracic anesthesia as a higher-risk setting in terms of aerosolization and of healthcare providers’ exposure to biological risks.
