ERENCE PROCEEDING
Endotracheal Intubation in Patients with
1. Introduction
Coronavirus disease 2019 (COVID-19) is a new respiratory tract infection. In Thailand, it was first recognized on 12 Jan 2021. While most patients with COVID-19 have no or mild symptoms, severe cases developed acute respiratory failure and need endotracheal tube intubation, including patients who need general anesthesia for surgery. Among persons infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19, approximately 8% will require endotracheal intubation and mechanical ventilation [1]. Prior studies examining health care workers diagnosed with the 2003 severe acute respiratory syndrome (SARS), identified intubation and bag-mask ventilation as possible sources of aerosol generation. In meta-analysis examining SARS in health care workers, those performing tracheal intubation had an odds ratio for developing SARS of 6.6 in comparison to those health care providers who did not perform this procedure [2]. We collected data from COVID-19 patients in a Priest hospital in Bangkok to investigate demographic data, intubation techniques, complications after intubation and prevalence of COVID-19 infection in health care providers performing intubations.
2. Methods
The study protocol was approved by the Priest Hospital Ethics Committee. A retrospective study of all COVID-19 patients admitted and who underwent endotracheal tube intubation in the study Priest Hospital between 1 January 2021 and 31 December 2021 was conducted. The diagnosis of COVID-19 was made according to the WHO interim guidance [3]. Laboratory confirmation of SARS-CoV-2 was defined as a positive result of real-time reverse transcriptase polymerase chain reaction (RT-PCR) assay of naso-pharyngeal swabs. Prior Thai study collected data about endotracheal tube intubation in COVID-19 patients over a short period [4].
Information of COVID-19 cases with endotracheal intubation included demographic data, rate of required intubation, types of room for intubation, types of oxygen supplement before intubation,
oxygen saturation before intubation, source of oxygen for pre oxygenation, devices for intubation, technique of drug used for intubation and acute complications after intubation.
Descriptive statistics was used to summarize the characteristics of the participants. Doctors and nurse anesthetists were the members of intubation teams. They self- observed for symptoms of COVID – 19 infection and were tested with COVID-19 antigen test kits every week.
3. Results
There were 752 COVID-19 patients with confirmed SARS-CoV-2 infection by real time polymerase chain reaction (RT-PCR) admitted from January 1 to December 31, 2021. Of these, a total of 14 COVID-19 patients needed intubation. Thirteen patients were intubated due to acute respiratory failure and 1 patient was intubated for general anesthesia. The patients’
characteristic and underlying diseases are described in Table 1. All of the patients were male because they were monks. Four patients (28.6 %) were 20-60 years old, 3 patients (21.4 %) were 60-70 years old, and 7 patients (50%) were more 70 years old. The mean age was 67.3 years old.
The eldest patient was 96 years old and the youngest 40. Of 14 patients, only one patient was normal weight, 3 patients (21.4 %) were overweight (having a body mass index of 23-24.9), 6 patients (42.9 %) were level 1 obese (BMI of 25-29.9), and 4 patients (28.6 %) were level 2 obese (BMI of 30 or more). All of patients had underlying diseases, most commonlyobesity, diabetes mellitus and hypertension in this order.
Endotracheal intubation was performed in a negative pressure isolation room for 13 patients (92.9 %) and 1 patient (2.1 %) was intubated in isolation room for general anesthesia and surgery. After surgery, the room was cleaned and disinfected immediately.
Clinical characteristics before and after intubation are presented in Table 2. Most of the patients had high flow nasal cannula for supplemental oxygen therapy before intubation.
There were 6 patients (12.9 %) with mild desaturation. 5 patients (35.7 %) with moderate desaturation and 3 patients (21.5 %) with
Table 1. Demographic data and medical characteristics of intubated COVID-19 patients
Count Ratio
Gender
Male 14 100 %
Female 0 0 %
Age (year)
0 – 19 0 0 %
20 – 60 4 28.57 %
60 – 70 3 21.43 %
> 70 7 50 %
BMI (kg / m2) WHO Asian-BMI classification
< 18.5 (underweight) 0 0 %
18.5 – 22.5 (normal weight) 1 7.14 %
23 – 24.9 (over weight) 3 21.43 %
25 – 29.9 (level 1 obesity) 6 42.86 %
> 30 (level 2 obesity) 4 28.5 %
Underlying disease
Diabetes mellitus 10 71.43 %
Hypertension 8 57.14 %
Coronary artery disease 2 14.23 %
Dyslipidemia 3 21.43 %
Chronic kidney disease 3 21.43 %
Hepatic failure 1 7.14 %
Table 2. Clinical characteristic before and after intubation
Count Ratio
Oxygen support before intubation
Oxygen cannula 1 7.14 %
Oxygen mask with reservoir bag 1 7.14 %
High flow nasal cannula 12 85.71 %
Oxygen saturation before intubation
Mild desaturation (90 -95 %) 6 42.85 %
Moderate desaturation (80 -85 %) 5 35.71 %
Severe desaturation (< 80 %) 3 21.43 %
Pre oxygenation
Self inflating bag and reservoir bag 13 92.86 %
Anesthetic circuit with mask 1 7.14 %
Devices used for intubation
Disposable Glidescope 13 92.86 %
Macintosh direct laryngoscope 1 7.14 %
Drugs used far intubation
None 6 42.86 %
Sedative drugs (propofol, diazepam) 2 14.29 %
Hypnotic drugs and neuromuscular blocking agents (propofol, succinylcholine)
6 42.86 %
Difficulty intubation
Yes 1 7.14 %
No 13 92.86 %
Complication
Severe desaturation (marked decreased from before intubation) 1 7.14 %
None 13 92.86 %
severe desaturation. Most of the patients on supplemental oxigen were ventilated using self- inflating bag with reservoir bag for pre-oxygenation. Only one patient received anesthesia circuit with face mask (not positive pressure ventilation) for pre- oxygenation. All off cases used bag mask with high-efficiency particulate air (HEPA) filter. We used videolaryngoscope and endotracheal tube stylet for every intubation. One patient could not be intubated under videolaryngoscope, but the performer accomplished successful intubation using Macintosh laryngoscope. All patients had some degree of desaturation before intubation.
After intubation most of the patients had oxygen saturation similar to before intubation and after mechanical ventilation oxygen saturation was increased. Only one patient had temporary decreased oxygen saturation from 80% to 40-50
% due to difficult intubation. None of patient need tracheostomy or emergency airway procedure.
The intubation teams included 9 health care personnel (4 doctors and 5 nurse anesthetists).
They self-observed for symptoms of COVID-19 infection and they were tested with COVID-19 antigen test kits every week. None of them was infected with COVID-19 within 2 weeks after performing this procedure.
4. Discussion
In 2021 during the COVID-19 pandemic, the Priest Hospital in this study admitted 752 COVID-19 patients of these 14 COVID-19 patients (1.9 %) needed intubation. All of them had underlying diseases. In this study, almost all cases received the intubation in a negative pressure isolation room [5-7], except one case who was intubated in isolation room (normal pressure) for general anesthesia because at the time the operation rooms were normal pressure ones. Recently, the COVID-19 pandemic highlighted the potential utility of video laryngoscopy to both reduce difficult intubation with its associated complications and reduce intubation provider contamination [5, 6]. We found that, critically ill patients with COVID-19 were desaturated at the time of endotracheal tube intubation. There were 8 of 14 patients moderate
to severe desaturated. Therefore, we used sedative drug or neuromuscular blocking for intubation in these patients to reduce the risk of severe hypoxemia during and after intubation. In this study the health care personnel used full personal protective equipment (PPE) that included a respirator with a rating of N95 or higher, gowns, gloves and eye protection and doffing the full PPE in anteroom [5, 6]. After doffing, the proceduralists washed body and hair [5, 6]. In our study, none of 9 health care personnel in the intubation teams (4 doctors and 5 nurse anesthetists) was infected with COVID-19 within 2 weeks after performing this procedure.
The novel coronavirus imposes an increased risk for aerosol borne transmission of viral particles to personnel performing endotracheal intubation.
COVID-19 is predominantly transmitted through droplet, aerosol and fomite but this study did not find COVID-19 infections among intubators and assistants. The limitation of this study was that if the intubation teams were infected with COVID-19 within 2 weeks after performing the procedure, they may have been infected from other sources since they live in endemic area of COVID-19 disease.
5. Conclusion
In severe cases, patients with COVID-19 infection may develop acute respiratory failure and need endotracheal intubation. Endotracheal intubation in patients with COVID-19 poses a risk of infection for the health care personnel involved in the procedure. In this study no personnel was infected with COVID-19 after performing intubation. The results suggest that, full personal protective equipment, video laryngoscopy, skills with multiple intubation techniques and proper medications were important components for patients and health care personnel's safety.
References
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doi: 10.1111/anae.15170
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