Advanced airway management and drug-assisted intubation skills in an advanced critical care practitioner team

Airway management, including endotracheal intubation, is one of the cornerstones of care of the critically ill patient. Multiple reports have examined the role of health professionals from varying backgrounds who have delivered endotracheal intubation as part of their critical care role (Gunning et al, 2013; Delorenzo et al, 2018; Gellerfors et al, 2018). In the UK, drug-assisted endotracheal intubation has remained restricted to a small number of professional groups, and within adult critical care has been almost exclusively performed by physicians. UK advanced practitioners in paediatric, neonatal and pre-hospital care perform drug-assisted endotracheal intubation as part of a multidisciplinary team (with medical supervision). However, published research on the subject is scant. Critical care paramedics (working within specialist prehospital care teams and under medical supervision) perform drug-assisted endotracheal intubation, as do anaesthesia associates (in the theatre environment) (McQueen et al, 2015). In the past 14 years advanced critical care practitioners (ACCPs) have been added to the multidisciplinary team of UK intensive care units (ICUs). Many aspects of ACCP practice have been described, including advanced airway management (Department of Health and Skills for Health, 2008; Faculty of Intensive Care Medicine, 2018; Denton et al, 2019; Williams et al, 2019; Denton et al, 2021). The extent to which ACCPs are involved in airway management varies between services with varying degrees of maturity and remains a contentious issue for medical colleagues.

This article outlines the development of airway management skills within a single ACCP team and reports a case series describing the safety profile of drug-assisted intubation in this context.

ACCP advanced airway management

The ACCP team has developed over an 8-year period within a conglomerate of three district general hospitals (Heartlands, Goodhope and Solihull hospitals, HGS) comprising 26 critical care beds. The team is primarily based at Heartlands Hospital in Birmingham, which is the largest of the three. The current cohort of qualified ACCPs were credentialed via the 2008 Department of Health framework (Department of Health and Skills for Health, 2008). This document has since been superseded by an updated process run by the Faculty of Intensive Care Medicine (FICM) (2018). The process of ACCP training has been discussed previously (Department of Health and Skills for Health, 2008; FICM, 2018; Williams et al, 2019; Campbell, 2020). The competency matrix for ACCPs includes comprehensive airway assessment and provision of airway management as part of treatment of cardiorespiratory arrest, including being able to perform endotracheal intubation where drugs are not required. Data from the ACCP intubation case series are also used as part of the team's yearly performance review, revalidation and competency portfolio, creating incentive for individuals to submit data.

Skill development

The development of airway management skills during ACCP training and after accreditation is multifaceted. Basic airway skills are central to this; use of airway adjuncts, bag valve mask ventilation and laryngeal mask airway are the minimum skill set and all members of the team are accredited Resuscitation Council (UK) advanced life support (ALS) providers and instructors. These skills are frequently practised through ACCP involvement in the hospital's adult emergency response team and care of critically ill patients in the ICU and inter/intra-hospital transfer of critically ill patients.

Opportunities to practise elective airway management and endotracheal intubation are also provided by supervised practice in the theatre environment, with anaesthetic-intensivist qualified senior doctors. This experience includes face mask ventilation, use of supraglottic airways and endotracheal intubation. ACCPs achieve more than 80 endotracheal intubations during the initial training period. After the 2-year ACCP training period, additional opportunities for elective airway management in the theatre environment are provided on an ongoing basis. In situ clinical environment simulation training in airway management is supported by formal training courses, including the Training in Emergency Airway Management (TEAM) course (https://teamcourse.co.uk) and the Coventry Airway Lab (https://tinyurl.com/2ejw7eyt). These focus on both technical skills and human factors including situational awareness and team dynamics.

The final element is ongoing direct supervision of clinical practice, this is usually via a senior ICU registrar or consultant. The HGS service takes a team approach to airway management, whether on the ICU or in other areas of the hospital. As a result, the process of intubation is one of having the appropriate skill mix, preparation and role allocation, rather than a focus on ‘who’ is actually performing the laryngoscopy. This will often involve an ICU consultant or registrar, ACCP and an ICU or critical care outreach nurse. This collaborative approach to airway management is supported by the Difficult Airway Society (Higgs et al, 2018).

It is unknown whether the team's approach to acquiring airway management skills is typical or unique for ACCPs; there are no published data on the issue, and an extended skills framework for advanced airway management has only recently been produced by FICM (2022).

Audit

Since 2016 the team has collected data regarding certain aspects of the scope of practice including central venous catheterisation, transfer of critically ill patients and intubation. Data were captured on all critical care intubations performed by doctors and ACCPs, both unassisted and drug-assisted intubation. This audit focuses on ACCP-conducted drug-assisted intubation. All intubations were supervised by either an ICU registrar or consultant, the usual practice being that they would deliver the induction agents and act as second intubator if one was required.

Measures

Patient-anonymised data were collected using 49-item Google Forms (an example form is available here: https://tinyurl.com/2p98nsur). Data for each event were submitted shortly after a completed intubation via the individual's smartphone. Data were reviewed monthly by a single reviewer (GD), with missing or incomplete data requested from the completing professional.

Analysis

Data are presented using simple descriptive statistics. Categorical data are summarised by the number in each category and percentage of the group as a whole.

Ethical considerations

As a routine audit of clinical practice, within the context of organisation-approved scope of practice, consent was not required for data collection. Institutional approval for audit was provided (reference 4461).

Results

Data were available from December 2016 to March 2021. Over this period, the HGS ACCP team carried out 675 endotracheal intubations. A small proportion of these intubations were not drug-assisted and were carried out during resuscitation for cardiac arrest (n=86, 12.7%). These were conducted without medical supervision as part of the hospital's adult emergency team. The results focus on drug-assisted/supervised intubations only, which comprise 87.2% (n=589) of the overall procedures. Half of the intubations (n=307) were carried out within the critical care units (ICU/high-dependency unit). The largest number of procedures carried out in non-critical care areas was in the resuscitation area of the emergency department (n=185, 31.4%). The remainder were carried out in non-critical care wards or areas such as the cardiac catheterisation suite (Table 1). Adults comprised 99.4% of patients intubated, with three paediatric cases. Respiratory failure was the most common reason for intubation, constituting 46.1% (n=272) of procedures, 10% of respiratory failure cases were the result of COVID-19. A low Glasgow Coma Scale (GCS) score featured in 21.7% (n=128) of cases.

Drug-assisted intubation was carried out in 96.6% (n=569) of events. A small minority, 3.3% (n=20), were carried out without sedation or neuromuscular blockade—these patients were largely post cardiac arrest or peri-arrest, unconscious and haemodynamically unstable. Propofol was the chief induction agent used (n=454, 77.1%), followed by ketamine (n= 88, 14.9%), thiopentone or benzodiazepines were used in 4.1% (n=24) and no anaesthetic was given in 3.9% of cases. Neuromuscular blockade was administered in 96.6% of intubations, with rocuronium used in 89.8% (n=529) patients, 6.8% (n=40) received suxamethonium, a small number of patients were intubated without neuromuscular blockade (3.3%, n=20). Only 48.6% (n=286) received an opioid as part of induction of anaesthesia (Table 2).

The majority of intubation attempts used direct laryngoscopy (n=434, 73.6%); video laryngoscopy accounted for 26.3% (n=155) of procedures. Grade 1 Cormack Lehane (CL) view was achieved on 71.3% (n=420) of occasions, grade 2 in 19.1% (n=113), grade 3 in 7.3%, in 2.2% (n=13) the CL grade was not reported (Table 2).

Overall, 99.8% (n=588) of patients were successfully intubated. Patients were intubated by the first clinician (ACCP) in 95.7% (n=588) of intubations, a second clinician (doctor) was required in 3.9% (n=23) of cases. A third clinician was required in two cases (0.3%). First pass success (a pass occurs when the laryngoscope has entered and been removed from the mouth) was achieved in 89.6% (n=528)of intubations. Second and third pass success were 8.6% (n=51) and 1.5% (n=9) respectively. There was a single case of failure to intubate, this patient was transferred to theatre for intubation following successful ventilation with a supraglottic airway. There were no cases of ‘can't intubate, can't oxygenate’, or need for emergency front-of-neck access.

No complications were recorded in 57.7% of intubations (Table 3). The most common complications were a reduction in oxygen saturation (<93% measured by pulse oximetry) and hypotension (a systolic blood pressure below 100 mm/Hg), these occurred in 22% (n=130) and 26.3% (n=155) of cases, respectively. The next most common complication was recognised oesophageal intubation, at 2.2% (13), there were no unrecognised oesophageal intubations. Aspiration of gastric content occurred in 0.34% (n=2) of cases. Cardiac arrest occurred in 1.1% (n=7) of intubations, death occurred in 0.5% (n=3).

Missing data

It was not possible to calibrate the data form against other administrative systems to identify missing data. The variability of location of patients means there are differing administrative systems between departments.

Discussion

Literature around the subject of advanced airway management and intubation performed by advanced clinical practitioners (ACPs) in any setting in the UK is sparse. This is despite the fact that advanced practitioners have been carrying out intubations in paediatric ICU, paediatric and neonatal critical care retrieval teams and critical care paramedics in pre-hospital services. The study by McQueen et al (2015) is the most substantial work on the subject, but is a relatively small study, with only 53 intubations carried out by critical care paramedics (McQueen et al, 2015). The HGS group published a small study early in data collection, incorporating 190 intubations (Denton et al, 2019). This case series represents the largest data set on intubations of critically ill patients by advanced practitioners in the UK.

A key quality indicator of endotracheal intubation practice is the first pass success (FPS) rate. This refers to the number of attempts to successfully place an endotracheal tube. An attempt is classed as the placement of the laryngoscope into the mouth and its removal. FPS is closely linked to adverse events: the greater the number of attempts at laryngoscopy, the greater the rate, and severity of complications (Cook et al, 2011; Sakles et al, 2013). With regard to acceptable FPS rates, Park et al (2016) performed a meta-analysis of studies from multiple countries regarding intubation success rates in emergency departments, in this an FPS of 84% was considered the minimum benchmark for intubation. An international study identified an FPS 79.8% in critically ill patients (Russotto et al, 2021). In the case series presented here, ACCPs achieved an 89.6% FPS. Arulkumaran et al (2018) reviewed the intubation log books of ICU trainees in the UK and discovered a 91.8% FPS when intubating critically ill patients, meanwhile, McQueen et al (2015) noted an 87.9% FPS in a UK pre-hospital emergency care team. It appears that if safe practice is based on FPS, this ACCP team performs at an acceptable standard when comparing with international and national published data. Stevenson et al (2007) showed an FPS of 75% for emergency physicians and 82% for anaesthetists in a Scottish emergency department case series.

Cormack Lehane (CL) view (how easily the vocal cords can be seen) may also be considered a measure of the intubator's skill at laryngoscopy—the significance being that CL view will influence FPS and therefore complications. The ACCP case series revealed a CL view of 1 (the vocal cords could be seen in their entirety) in 71.3% (n=420) of intubations. This is similar to that reported for ICU trainee doctors achieving CL views of 1 in 70.7% of critical care intubations (Arulkumaran et al, 2018).

The lack of agreed criteria for complications makes comparison between reports difficult. Although the reported complication rate here of 42.3% may appear high on first reading, the team took a liberal approach to defining complications including limits at which patients are unlikely to come to significant harm. Any deviation below a saturation of 93% was recorded as ‘hypoxia’, other studies only included more marked desaturations, with a threshold of 80% reported by Rissotto et al (2021). When comparing the threshold of ‘severe hypoxia’ (<85%), 8% (n=47) fell below this level (Table 4), which approximates the 9% reported by Russotto et al (2021). Similarly, the definition of severe hypotension used here (systolic blood pressure <80 mmHg) occurred in 14% of patients, compared with 10% falling below Russotto et al's (2021) more strict definition of <65 mmHg.

Comparisons are more easily made for the most serious complications, namely cardiac arrest and death. In the series shown here, cardiac arrest occurred in 7(1%) of cases, leading to death in just under half (n=3) of these patients. These rates are comparable with those of other publications of intubation of critically ill patients. Arulkumaran et al (2018) noted a cardiac arrest rate of 6.3%, Russotto et al (2021) 3.1%, Gellerfors et al (2018) 1.3%, Sakles et al (2013) 10.9%.

Many of the intubations carried out in this case series were external to the ICU (52%). These intubations in the absence of an ACCP, would likely be carried out with a single doctor with advanced airway management skills, with the support of a ‘flash team’ (an ad-hoc team of potentially unfamiliar individuals with variable skill and training). The advantage to the presence of two advanced airway management practitioners in this context is that it provides a significant reduction in the cognitive load of a high-stress, high-risk episode. This more team-based approach to intubation of the critically ill patient is advocated by the most recent Difficult Airway Society guidelines for the intubation of critically ill patients (Higgs et al, 2018).

Some of the benefits of having two intubators present during critical care intubations have already been discussed. A potential criticism of this model is the impact on junior doctor training. It is important to note that ACCPs do not intubate all critically ill patients within the ICU service. Due to the hospital administrative systems, it is not possible to accurately state the proportion of patients intubated by ACCPs compared with medical colleagues; however, the authors estimate approximately one-third of critical care intubations are carried out by ACCPs. The team as a whole endeavours to provide a balance of learning opportunities and skill maintenance across the multidisciplinary spectrum. The ‘two intubator’ model also benefits medical colleagues in situations where the ACCP is not the first intubator, but the patient may be physiologically or environmentally challenging to intubate.

Limitations

As a single-centre study involving a well-established team operating over 8 years, external validity is debatable. ACCPs nationwide are in various states of training and maturity. Across the UK, not all ACCP teams carry out endotracheal intubations. On this basis, it is not possible to extrapolate the findings from this case series to ACCPs nationally. There is the possibility of selection bias in cases of ACCP intubation. Due to inconsistency in capturing intubations carried out by doctors, comparing patient selection between the two professions is difficult. It is possible that ACCPs in this case series are selecting patients who are anatomically or physiologically easier to intubate.

Conclusions

Using a multi-modal approach, this ACCP service has developed a process to acquire advanced airway management skills including endotracheal intubation. Under medical supervision, ACCPs delivered advanced airway management achieving a first pass success rate of 89.6%, which contrasts favourably with both international and national success rates. Although complications were experienced in 48.3% of patients, when similar complication cut-offs are compared with published data, ACCPs also compare favourably with published data.

KEY POINTS

• Internationally, health professionals from varying professional backgrounds deliver endotracheal intubation as part of their critical care role
• A key quality indicator of endotracheal intubation practice is the first pass success rate
• Under medical supervision, advanced critical care practitioners (ACCPs) in this team delivered advanced airway management achieving a first pass success rate that contrasts favourably with both international and national success rates
• When comparing complications using similar parameters to those in previously published data, ACCPs compared favourably

CPD reflective questions

• What guidelines inform standards and safety around the intubation of critically ill patients? How familiar are you with these?
• What are the quality indicators of a successful intubation?
• Based on current guidelines, what is the ideal make up of an intubation team? Why?