Intubation of COVID patients: always a risky business?

We thank El‐Boghdadly et al. for their article reporting the incidence of coronavirus disease 2019 (COVID‐19) in healthcare workers following tracheal intubation [1]. Their study found a 10.7% incidence of COVID‐19 following tracheal intubation in patients with confirmed or suspected COVID‐19. During the same period, we conducted a prospective service evaluation at our institution to assess laryngoscopists' risk of COVID‐19 acquisition. Our findings differed from those of El‐Boghdadly et al. and so we present a summary of our service evaluation and a rationale for the differences.

The service evaluation was registered with Imperial College Healthcare NHS Trust and data were collected prospectively from 11 March to 30 April 2020. Inclusion criteria were: patient age > 18 years; absence of a negative COVID‐19 ribonucleic acid polymerase chain reaction (RNA‐PCR) test; and tracheal intubation for any indication. Following tracheal intubation, a questionnaire was completed detailing the indication, COVID‐19 status of the patient and the availability and usage of personal protective equipment (PPE). Questionnaire completion was mandatory. COVID‐19 status was classified as ‘confirmed’ (RNA‐PCR test positive), ‘suspected’ (fever or new persistent cough, no RNA‐PCR test) or ‘unable to exclude’ (no fever or cough, no RNA‐PCR test). Clinical data were extracted retrospectively from the electronic patient record. Laryngoscopist health 5, 10 and 14 days post‐intubation was obtained from the electronic staff rota, and categorised as ‘healthy, at work’, ‘healthy, self‐isolating’ (due to a household member with symptoms of COVID‐19) or ‘sick, off work’.

The first death in London from COVID‐19 occurred on 12 March 2020 at our institution [2]. This, in addition to the deficiency in local stocks, spurred the development of a steering group to establish resilient supply chains for World Health Organization (WHO) standard PPE [3]. By 17 March, we had independently sourced PPE, including reusable respirators and visors and, by 24 March, had formalised infection control, cleaning protocols and training.

Seventy‐two patients' tracheas were intubated during the data collection period. The most common indications were hypoxia (n = 34; 47%) and surgical operations (n = 20; 28%). A total of 24 (33%) intubations were performed in the emergency department, 20 (28%) on a general ward, 14 (19%) in the intensive care unit and 14 (19%) in an operating theatre. Patients' COVID‐19 status and laryngoscopists' health are reported in Table 1. WHO standard PPE was available for all intubations and was used in 70 (97%) cases.

Table 1.

Patient COVID status and laryngoscopist health post‐intubation. Values are number (proportion).

Parameter
Patient COVID status at the time of intubation	n = 72
Confirmed	22 (31%)
Suspected	32 (44%)
Unable to exclude	18 (25%)
Patient COVID RNA‐PCR status*	n = 72
Positive	48 (67%)
Negative	17 (24%)
Not tested	7 (10%)
Laryngoscopist health post intubation	Day 5	Day 10	Day 14
Healthy, at work	68 (94%)	68 (94%)	69 (96%)
Healthy, self‐isolating	4 (6%)	4 (6%)	3 (4%)
Sick, off work	0 (0%)	0 (0%)	0 (0%)

^*The result of the RNA‐PCR test was not always known at the time of intubation.

The absence of laryngoscopist illness in our service evaluation differs from the 10.7% incidence reported by El‐Boghdadly et al. [1]. The potential reasons for this difference are: improved availability of PPE; reduced risk of selection bias; and a shorter follow‐up period. El‐Boghdadly et al. reported use of WHO standard PPE [3] in only 87.9% of cases and the level of training in the use of PPE is not reported [1]. A risk of the non‐mandatory self‐reporting method of El‐Boghdadly et al. is the potential for reporting bias; that is, laryngoscopists who developed symptoms might have been more likely to self‐report, leading to an overestimation of the incidence. In 99% of cases, the incubation period for COVID‐19 is 14 days or less [4]. The use of a longer follow‐up period by El‐Boghdadly et al. (40 days) [1] may also have led to an overestimation, due to unrelated acquisition of COVID‐19.

In summary, El‐Boghdadly et al. highlight the potential risk of intubating COVID‐19 patients, whereas our service evaluation demonstrates that effective procurement, usage and decontamination of WHO standard PPE can reduce this risk. If elective surgery is to be re‐established whereas COVID‐19 is prevalent, the focus on effective PPE must be maintained in order to minimise the risk of COVID‐19 transmission to healthcare workers.