Role of anaesthesiologists during the COVID-19 outbreak in China

From December 2019, a respiratory disease caused by the novel coronavirus severe acute respiratory syndrome (SARS-CoV-2) was traced to Wuhan, China, and transmitted to more than 143 countries. On January 30, 2020, the WHO designated the novel coronavirus pneumonia outbreak as a global health emergency and named it coronavirus disease 2019 (COVID-19). As of March 15, 2020, a total of 81 048 confirmed COVID-19 cases had been reported in China.¹ Starting on January 24, 2020, the traditional Chinese New Year's eve, more than 42 000 healthcare providers from all over China gathered in Wuhan to support the local healthcare system (data from National Health Commission of China). Among them, more than 1000 were anaesthesiologists (data from the Chinese Society of Anaesthesiology [CSA]). In the battle against COVID-19, Chinese anaesthesiologists explored new working models to improve patient outcomes and minimise the risk of contracting COVID-19.

Airway management team

COVID-19 has similarities and differences with SARS and Middle East respiratory syndrome (MERS) in terms of infectious period, transmissibility, clinical severity, and extent of community spread (Table 1 ). With the increasing knowledge of the clinical progress of COVID-19 cases, the timing of invasive ventilation changed. As indicated by CT results,⁹ 5–8 days after onset of initial symptoms the infection rapidly aggravated and extended to a bilateral multi-lobar pulmonary effusion and consolidation. Although noninvasive ventilation temporarily improves oxygenation in COVID-19 patients, it may not necessarily change the natural course of acute respiratory distress syndrome (ARDS).¹⁰ On February 18, 2020, the state council of China issued ‘Question and answers of tracheal intubation for novel coronavirus pneumonia cases’, in which the criteria for tracheal intubation were defined as oxygenation index <150 mm Hg after at least 2 h of continuous positive airway pressure (CPAP) with 100% oxygen, and it was recommended that intubation be scheduled rather than emergent. According to the new criteria, patients would receive intubation and ventilation therapy earlier. As a result, more patients needed intubation. In many hospitals, airway management teams consisting of skilled anaesthesiologists were established to meet the need for intubation.

Table 1.

Comparison of COVID–19, SARS and MERS. ∗Data as of March 15, 2020. ^†Data up to 2003. ^‡Data up to November 2019. COVID, coronavirus disease; ARDS, acute respiratory syndrome; MERS, Middle East respiratory syndrome; GGO, ground-glass opacity; SARS, severe acute respiratory syndrome.

Characteristics	COVID-19	SARS	MERS
Clinical symptoms	Presence or absence of cough, sore throat, shortness of breath, fever, myalgia	Cough, dyspnoea, fever, chill, malaise, headache, diarrhoea	Sore throat, dry cough, dyspnoea, fever, chill, rigors
Epidemiology	R0: 2.2–6.49, mean 3.282 Pre-symptomatic transmission exists	R0: 2–5 Peak viral shedding occurs after patients were already quite ill	R0<1
Mortality	5735/15 3517 (3.7%)∗1	774/8096 (9.6%)†3	858/2494 (34.4%)‡4
CT results2	Multifocal patchy GGOs with subpleural distribution, progresses into diffuse heterogeneous consolidation with GGO	Subpleural GGO and consolidation, prominent lower lobe involvement, interlobular septal and intralobular septal thickening	Bilateral, basilar and subpleural airspace, extensive GGO and occasional septal thickening and pleural effusions
Pathology
Lung	Early phase5: lung oedema, proteinaceous exudate with globules, patchy inflammatory cellular infiltration Late phase6: pulmonary oedema with hyaline membrane formation, interstitial mononuclear inflammatory infiltrates, viral cytopathic-like changes in the intra-alveolar spaces	Bilateral lung extensive consolidation, localised haemorrhage and necrosis, desquamative pulmonary alveolitis and bronchitis, proliferation and desquamation of alveolar epithelial cells Viral particles in lung tissue7	Necrotising pneumonia, pulmonary diffuse alveolar damage7
Other organs	Mild interstitial mononuclear inflammatory infiltrates in the heart6 Influence on other organs still not defined8	Massive necrosis of splenic lymphoid tissue; systemic vasculitis; thrombosis in small veins; degeneration and necrosis of parenchyma cells in the lung, liver, kidney, heart, and adrenal gland7	Acute kidney injury, portal and lobular hepatitis and myositis with muscle atrophic changes. Brain and heart were histologically unremarkable7

Depending on the anaesthesiologists available, the airway management team size was 4–18 people. Airway management team members worked in rotation, with only one to two anaesthesiologists in the isolation ward at a time. The minimal size helps avoid unnecessary viral exposure. An intubation cart containing modular packs of medicines and materials was kept in the ward to minimise the traffic of people bringing materials into the room. Videolaryngoscopy with a replaceable blade was widely used to avoid placing the face of the anaesthesiologist close to the patient. Light wand, laryngeal mask airway (LMA), flexible bronchoscope, and cricothyroid puncture kit were also available in the cart in case of difficult intubation. Protocols for unanticipated difficult airway were followed, highlighting the role of an intubating LMA.¹¹

Any known or suspected COVID-19 patient must be regarded as ultra-high risk. Tracheal intubation of these patients is a high-risk aerosol-generating airway procedure requiring standard grade 3 personal protective equipment (PPE)⁴ including an N95 mask, goggles, face shield, double gown, double gloves, protective overshoes, and a powered respirator (powered air purifying respirators).

The Airway Management group of the CSA issued ‘Expert Recommendations for Tracheal Intubation in Critically ill Patients with Novel Coronavirus Disease 2019’ on February 22, 2020.⁴ According to these recommendations and current evidence, principles include minimising generation of aerosols (see Supplemental Digital Content 1 for guidance for tracheal intubation of COVID-19 cases).^{11 , 12} Bag-mask ventilation before intubation, patient coughing during laryngoscopy or intubation, and inadequate sedation putting the patient at risk of agitation can generate aerosols. With adequate pre-oxygenation, bag-mask ventilation can ideally be avoided. CPAP with 100% oxygen for 5 min is recommended for pre-oxygenation. If available, high-flow nasal cannula (HFNC) delivery systems can be used for pre-oxygenation, although these can increase the risk of viral spread through aerosol generation.¹³ To minimise this risk, the mouth and nose of the patient can be covered with normal saline saturated gauze during pre-oxygenation. To avoid agitation and cough, intubations are best done using a rapid sequence intubation technique.^{11 , 12} Midazolam, propofol, and etomidate can be used depending on the patient's condition. After sedation, at least 0.9 mg kg⁻¹ of rocuronium or 1 mg kg⁻¹ of succinylcholine should be used. A hydrophobic filter should be attached to the resuscitation bag, between the mask or tracheal tube (TT) and the bag. When difficult airway is anticipated, flexible bronchoscopic intubation can be performed using a videobronchoscope. Awake fibreoptic intubation should be avoided to decrease exposure to aerosols.¹² If unanticipated difficult airway occurs, an intubating LMA and surgical airway can be considered.

Extubation with minimal agitation and coughing is important for both ICU patients and surgical patients. Careful suctioning with a closed sputum suction device before return of consciousness can be important.¹⁴ A recent meta-analysis¹⁵ reported that procedures (including dexmedetomidine, remifentanil, fentanyl, and lidocaine i.v., intracuff, tracheal, or topical) were all better than placebo in reducing moderate to severe emergence cough, with dexmedetomidine ranked as the most effective. Dexmedetomidine and lidocaine by various routes have been used in COVID-19 cases. Extubation before return of consciousness is recommended for patients without a difficult airway.¹⁴ However, a device for reintubation should be available. Extubation without removal of the filter is important.¹¹

Intensive care

Anaesthesiologists in surgical ICUs (SICU) and anaesthesia ICUs (AICU) contribute considerably to the management of COVID-19 cases. At Jinyintan Hospital in Wuhan,¹⁶ of 17 patients who developed ARDS, 11 worsened within a short period. At Zhongnan Hospital in Wuhan,¹⁷ 47.2% of patients in the ICU received invasive ventilation and four were switched to extracorporeal membrane oxygenation (ECMO). Preprint reports of deaths revealed that durations from initial symptoms to death were short (15 days; inter-quartile range, 11–20 days).¹⁸ Autopsy results of COVID-19 cases indicated very sticky mucus in the small airways.¹⁹ A high percentage of patients in the ICU require ‘active’ invasive airway intervention, and critically ill patients may benefit from ECMO, two fields that anaesthesiologists are expert in.

Du-ring the outbreak, critical care services in China were confronted with a rapid increase in demand for resources. All hospitals and other organisations were involved in the care for COVID-19 cases. In many hospitals, airway team members took charge of ventilation management after tracheal intubation. Once intubated, classical ventilation strategies^{13 , 19} have been effective in critically ill COVID-19 patients, including lung protective mechanical ventilation strategies and prone position ventilation. Lung protective mechanical ventilation strategies include low target tidal volume (6 ml kg⁻¹ predicted body weight), plateau pressure ≤30 cm H₂O, target SaO₂ 88–95%, pH ≥7.25, and intermittent recruitment manoeuvres.²⁰

Ultrasonography, another technique widely used in the field of anaesthesiology during the past decade in China, was very useful in the management of critically ill COVID-19 patients. Anaesthesiologists usually use ultrasound for nerve blocks, vascular puncture and emergency screening of the chest and abdomen. Given potential delay in obtaining examinations including chest radiography for patients under airborne isolation, portable ultrasonography is useful to quickly assist in the diagnosis of conditions such as pleural effusion and pneumothorax.¹³ PPE, especially purifying respirators, can preclude procedures such as auscultation. Ultrasonography can also be used in airway evaluation and determination of TT depth.²¹

Fast response resuscitation team

Based on experience during the SARS outbreak,¹³ fast response resuscitation teams made up mostly of anaesthesiologists were organised in some hospitals in Wuhan. Members of the resuscitation team stayed on call near the isolation area. During initial resuscitation efforts by the first responder, fast response resuscitation team members would don PPE and take charge of the resuscitation. Like the airway management cart, the resuscitation cart was equipped with modular medicine and equipment to avoid unnecessary traffic. The team size is typically minimised to four to avoid unnecessary viral exposure.

Clinical anaesthesia

During the outbreak of COVID-19, the most important consideration for clinical anaesthesia is infection control. By February 10, 2020, most hospitals in China accepted emergency cases only. However, recently elective surgeries have increased rapidly. Besides Wuhan, many other areas could also have many infected people. Thus, anaesthesiologists play an essential and demanding role in the preoperative evaluation of COVID-19 infection risk (Supplemental Digital Content 2 shows a fast triage flowchart). At present, suspicion for infection with COVID-19 requires two symptoms with an epidemiological link, or three without epidemiological link.¹⁹ Epidemiological links include travel within 14 days to affected areas, or close contact within 14 days of illness onset with a confirmed patient, or close contact with a person having fever and respiratory symptoms and travel to an affected area within 14 days of illness onset.¹⁹ Fever may not be present in all patients. The absence of fever in COVID-19 is more frequent than in SARS and MERS, so appropriate infectious control precautions should be in place even in those without typical symptoms.²² With the spread of the virus to more areas and countries, anaesthesiologists all over the world may face the challenge of weighing the risk of infection and the need for medical care of patients.

Role of academic anaesthesiology organisations in China

Chinese academic anaesthesiology organisations immediately reacted to the COVID-19 outbreak, focusing on improving medical care and protecting anaesthesiologists.

Psychological support for front-line anaesthesiologists

In the care of COVID-19 patients, anaesthesiologists are vulnerable to both infection and mental health problems. They may experience depression by the situation, fear of contagion, and fear of spreading the virus to their family and others. The heavy workload and discomfort of wearing PPE for long durations can worsen the depression. Healthcare workers in high-risk clinical settings such as SARS units had substantially more post-traumatic stress symptoms.²³ On February 13, 2020, the CSA established a platform to provide psychological support for healthcare providers, especially for front-line anaesthesiologists and their families. More than 20 psychologists provided consultations for anaesthesiologists who took care of COVID-19 patients.

Continuous update of information on COVID-19

Clear communication with regular and accurate updates about the COVID-19 outbreak were provided to anaesthesiologists in order to improve quality of care and to address their sense of uncertainty and fear. The CSA and Chinese Association of Anaesthesiologists (CAA) issued and updated a series of practice recommendations and consensus guidelines, covering facility organisation and anaesthetic care during the outbreak of COVID-19 pneumonia. One of the most recent was expert recommendations for anaesthesia and infection control in elective surgeries during recovery after outbreak.¹⁴ The CSA also established a platform for information on COVID-19 patient care.²⁴ The most frequently asked questions about COVID-19 are continuously collected and answered.

Online discussion of anaesthesia care by experts and front-line anaesthesiologists

The CSA and CAA organised online discussions on various topics including airway management, infection control, and medical care of specific populations, such as parturients, during the outbreak of COVID-19. Experts with experiences in H1N1, SARS, and Ebola management and front-line anaesthesiologists were invited into the discussions.

In conclusion, Chinese anaesthesiologists were essential to various critical aspects of the response to the outbreak of COVID-19. Earlier invasive ventilation, establishment of airway management teams and fast response resuscitation teams, and use of point-of-care ultrasonography were major contributions. With the change in epidemiologic characteristics of COVID-19 patients, anaesthesiologists took on the responsibility of infection control as well.

Authors' contributions

Conception: ZL, HD

Data collection: ZL, MY

Writing of the draft: MY

Revision of the manuscript: ZL, HD

All authors approved the final version of the manuscript

Declarations of interest

The authors declare that they have no conflict of interest.

Funding

National Science Foundation of China (No. 81871028) and Nature Science Foundation of Shaanxi Province (No. 2018-SF-277).

Appendix A. Supplementary data

The following is the Supplementary data to this article: