Implementation and initial validation of a multicentre obstetric airway management registry

Abstract

Background: In Africa, maternal mortality after caesarean delivery is 50 times greater than in high-income countries. In South Africa, more than 50% of anaesthesia-related maternal mortality is attributed to failure to protect the airway. We implemented an obstetric airway management registry, to facilitate future improvements in management and outcomes.

Methods: A prospective electronic registry was established at three obstetric sites in Cape Town, recording airway management for all general anaesthetics from 20 weeks gestation to seven days post-partum. Perioperative descriptive data are entered using a web-based smartphone-enabled platform. To quantify the reliability of capture, we compared the first 200 records in the registry to theatre logbooks. We used summary statistics to describe our obstetric anaesthesia population, and details relevant to airway management.

Results: The first 200 cases were recorded from September 2018 to January 2019. According to theatre logbooks, this represented 80% of cases performed. Major indications for general anaesthesia included severe fetal distress/bradycardia (21%), failed neuraxial technique (19%), coagulopathy (19%), and abnormal placentation (12%). A third of patients had hypertensive disorders of pregnancy, and 6% had imminent/confirmed eclampsia. Forty per cent were in active labour. On airway assessment, Mallampati grade was 3 or 4 in 29% of patients, and mouth opening, thyromental distance and mandibular protrusion limited in 10%, 8% and 8% respectively. Cormack-Lehane grade IIb and III views were encountered in 6% and 2% respectively, with no grade IV views. Desaturation below 90% occurred in 12% of patients. There were two cases (1%) of failed intubation with supraglottic airway rescue, and no emergency surgical airways performed.

Conclusion: An obstetric airway management registry was successfully implemented. Clinically significant hypoxaemia occurred commonly during general anaesthesia, with a high incidence of difficult intubation predictors and desaturation. The registry will guide research aimed at improving safety during general anaesthesia in obstetrics.

The full article is available at https://doi.org/10.36303/SAJAA.2020.26.4.2423 or http://www.sajaa.co.za/index.php/sajaa/article/view/2423 (Open Access)

Full text

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South Afr J Anaesth Analg 2020; 26(4) http://www.sajaa.co.za
Southern African Journal of Anaesthesia and Analgesia 2020; 26(4):198-205
https://doi.org/10.36303/SAJAA.2020.26.4.2423
Open Access article distributed under the terms of the
Creative Commons License [CC BY-NC 3.0]
http://creativecommons.org/licenses/by-nc/3.0
South Afr J Anaesth Analg
ISSN 2220-1181 EISSN 2220 -1173
© 2020 The Author(s)
ORIGINAL RESEARCH
Introduction
The African Surgical Outcomes Study showed that maternal
mortality after caesarean delivery is 50 times greater in Africa,
predominantly from obstetric haemorrhage and anaesthesia-
related hypoxaemia or pulmonary aspiration.1,2 The South African
Saving Mothers Report (2014–2016) showed that 61/87 (70%)
of anaesthesia-related deaths were attributed to complications
of airway management.3 Lack of skilled doctors was recorded
in 71% of these deaths, and a quarter of all anaesthetics were
administered by non-physician anaesthesia providers.3
Obstetric airway management features increased diculty and
complications.4 Anatomical and physiological changes that
occur during pregnancy increase the likelihood of dicult or
failed intubation,5 which may be up to eight times higher than in
the general surgical population.6-9 Maternal deaths from dicult
airway management have been highlighted in two reports of
the Condential Enquiries into Maternal Deaths in the United
Kingdom (2006–2008 and 2000–2002).10,11 The American Society
of Anaesthesiologists’ Closed Claims in obstetrics database
revealed that maternal deaths were more frequently associated
with general than regional anaesthesia, and that 16% of the
anaesthetic claims were due to critical events involving the
airway and respiratory system.12
We sought to describe the clinical characteristics, contributors
to, and outcomes of obstetric airway management within our
context, and to test an online data collection tool. We aimed
to quantify the reliability of captured cases; hence, the primary
outcome of this validation study was to establish the proportion
of the total number of general anaesthetics (GAs) performed,
which were captured in the registry. We therefore compared
the rst 200 patients in the registry with the number of theatre
logbook entries for the corresponding period. The secondary
outcome was a detailed description of our obstetric anaesthesia
population requiring GA, including predictors of dicult airway
management, and outcomes. The aim of this ongoing registry is
to address the lack of data in our context, identify trends, and
provide the basis for future quality improvement projects in
airway management.
Method
A multicentre Obstetric Airway Management Registry (ObAMR)
was established after approval by the Human Research Ethics
Committee (HREC) of the Health Sciences Faculty of the University
of Cape Town (UCT) (HREC Ref: R025/2018). The ongoing registry
was approved for a duration of three years from 26 September
2018 to 30 September 2021. Perioperative data describing
patient demographics, indications for GA, factors predictive of a
Background: In Africa, maternal mortality after caesarean delivery is 50 times greater than in high-income countries. In South
Africa, more than 50% of anaesthesia-related maternal mortality is attributed to failure to protect the airway. We implemented an
obstetric airway management registry, to facilitate future improvements in management and outcomes.
Methods: A prospective electronic registry was established at three obstetric sites in Cape Town, recording airway management
for all general anaesthetics from 20 weeks gestation to seven days post-partum. Perioperative descriptive data are entered using a
web-based smartphone-enabled platform. To quantify the reliability of capture, we compared the rst 200 records in the registry
to theatre logbooks. We used summary statistics to describe our obstetric anaesthesia population, and details relevant to airway
management.
Results: The rst 200 cases were recorded from September 2018 to January 2019. According to theatre logbooks, this represented
80% of cases performed. Major indications for general anaesthesia included severe fetal distress/bradycardia (21%), failed
neuraxial technique (19%), coagulopathy (19%), and abnormal placentation (12%). A third of patients had hypertensive disorders
of pregnancy, and 6% had imminent/conrmed eclampsia. Forty per cent were in active labour. On airway assessment, Mallampati
grade was 3 or 4 in 29% of patients, and mouth opening, thyromental distance and mandibular protrusion limited in 10%, 8% and
8% respectively. Cormack-Lehane grade IIb and III views were encountered in 6% and 2% respectively, with no grade IV views.
Desaturation below 90% occurred in 12% of patients. There were two cases (1%) of failed intubation with supraglottic airway
rescue, and no emergency surgical airways performed.
Conclusion: An obstetric airway management registry was successfully implemented. Clinically signicant hypoxaemia occurred
commonly during general anaesthesia, with a high incidence of dicult intubation predictors and desaturation. The registry will
guide research aimed at improving safety during general anaesthesia in obstetrics.
Keywords: airway management, general anaesthesia, hypoxaemia, obstetric anaesthesia, pregnancy, registry
Registry number: NHRD WC_201810_002
Implementation and initial validation of a multicentre obstetric airway
management registry
MI Smit, C van Tonder, L du Toit, D van Dyk, AR Reed, RA Dyer, R Hofmeyr
1Department of Anaesthesia and Perioperative Medicine, University of Cape Town, Groote Schuur Hospital, South Africa
2Department of Anaesthesia, Khayelitsha District Hospital, South Africa
Corresponding author, email: maretha.smit@uct.ac.za

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Implementation and initial validation of a multicentre obstetric airway management registry
dicult airway, airway management techniques, complications
and outcomes are collected at Groote Schuur (GSH), Mowbray
Maternity (MMH) and New Somerset (NSH) Hospitals under
the clinical supervision of the Department of Anaesthesia and
Perioperative Medicine of UCT.
All patients requiring GA after 20 weeks gestation and up to
seven days post-delivery are included. Simple verbal consent for
inclusion in the registry was approved by HREC. Preoxygenation
to an end-tidal oxygen fraction > 0.8, followed by rapid sequence
induction (RSI) and tracheal intubation with cricoid pressure is
taught as standard practice at our centres.4,13-16 However, the
GA technique provided is ultimately at the discretion of the
anaesthesiologist. All anaesthesia providers from the Department
of Anaesthesia and Perioperative Medicine of UCT can enter data
into the registry. Records are collected anonymously on REDCap
(Research Electronic Data Capture, https://www.project-redcap.
org/) during or immediately after the case by using an electronic
link sent to their smartphones (www.tinyurl.com/ObAMR), or by
scanning a QR code present in all obstetric theatres. The ObAMR
is maintained on a secure password protected UCT server.
Each electronic data capturing form is assigned a unique study
number, with no personal identifying information.
The HREC of the Health Sciences Faculty of UCT approved the
validation and initial description of the rst 200 cases entered
into the ObAMR (UCT HREC Ref: 341/2019). Data were collected
from 26 September 2018 to 9 January 2019. Data were extracted
from the REDCap server to an Excel spreadsheet (Microsoft,
Redmond, Washington, USA). The primary outcome was assessed
by establishing the proportion of general anaesthetics captured,
by comparing the number of records in the registry and the total
number of cases entered in the operating theatre logbooks over
the same time period. For secondary outcomes, baseline patient
characteristics were reported as mean (standard deviation
[SD]) for continuous normally distributed variables, median
(interquartile range [IQR]) for data not normally distributed,
and number (percentage) for categorical variables. In addition,
details relating to airway management were reported, includ-
ing experience of anaesthesia provider, airway assessment,
laryngoscopic view, and outcomes such as incidence of failed
intubation and rescue, and nadir of oxygen saturation (< 90%
dened as clinically signicant). The detailed data capture sheet
is available as Supplementary Material, Appendix 1.
Results
Cases were recorded at GSH (tertiary academic, 40%), MMH
(regional obstetric, 39%) and NSH (regional, 21%). When com-
pared to theatre logbooks, overall 80% of GAs were captured
in the ObAMR (Table I). The obstetric GA rate at these centres
was approximately 11% of all caesarean sections performed.
At MMH there was a failure to record conversions from regional
to general anaesthesia in the theatre logbooks, with one more
GA case entered in the registry than recorded in theatre. This
led to a falsely elevated capture rate of 101% at this institution.
We excluded 32 patients requiring GA for infertility procedures
(< 20 weeks gestation) at GSH, that had been entered in the
theatre logbooks. Two incomplete records in the registry, with
no location specied, were also excluded.
Table I: Validation data and location
GSH MMH NSH Total
Theatre logbooks 105*76 66 247
ObAMR 80 77 41 198†
Capture rate 76% 101% 62% 80%
GSH – Groote Schuur Hospital, MMH – Mowbray Maternity Hospital, NSH – New Somerset
Hospital, ObAMR – Obstetric Airway Management Registry
*32 ultrasound-guided oocyte retrievals at GSH were excluded (< 20 weeks gestation)
†2 incomplete records excluded; locations not specified
Patient demographic details are presented in Table II. Mean (SD)
age was 29.5 (6.4) years, weight 77.2 (19.6) kg and body mass
index (BMI) 29.3 (7.5) kg/m2. Median (IQR) gestational age was
37 (33–39) weeks. Major indications for general anaesthesia
included severe fetal distress/bradycardia in 21%, failed neuraxial
technique in 19%, suspected or conrmed coagulopathy in
19%, and the presence of abnormal placentation (e.g. abruptio
placentae/placenta praevia/accreta) in 12% of cases. Neuraxial
anaesthesia was the primary anaesthetic strategy in 24% of cas-
es who subsequently underwent GA. Hypertensive disorders of
pregnancy were present in 33%, with 6% developing imminent
or conrmed eclampsia. Forty per cent of patients were in active
labour.
Table II: Patient demographic details
Minimum Maximum Mean/
median SD/IQR n
Age
(years) 15 44 29.5 6.4 200
Height
(cm) 145 180 162.5 6.6 197
Weight
(kg) 39 170 77.3 19.6 197
BMI
(kg/m2)17.3 72.6 29.3 7.5 197
Gestation
(weeks) 20 42 37 33–39 190
Parity 0 8 1 0–2 199
Gravidity 1 8 2 1–4 199
BMI – body mass index, SD – standard deviation, IQR – interquartile range
In this analysis, 89% of anaesthesia providers were medical
ocers and/or anaesthesia registrars with more than one year
of experience of clinical anaesthesia. On airway assessment,
Mallampati grade 3 or 4 was present in 29% of cases, and mouth
opening, thyromental distance and mandibular protrusion were
limited in 10%, 8% and 8% respectively (Table III).
Rapid sequence induction with an endotracheal tube (ETT )
was the primary strategy in 72%. Suxamethonium was the
muscle relaxant used in 97% of cases. First-pass intubation
success was 87%, and an introducer was used in 21%. Traditional
Macintosh laryngoscope blades were used in 73% of intubations.
Videolaryngoscopes were available in 98%, but only used in 26%
of intubations. Cormack-Lehane grade IIb and III laryngoscopic

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Implementation and initial validation of a multicentre obstetric airway management registry
views were encountered in 6% and 2% respectively, with no
grade IV views.
Mild or severe airway oedema was encountered in 17%, as as-
sessed clinically during laryngoscopy. Range (median; IQR) of
saturation nadir was 15 to 100% (98; 95–99), with 12% of patients
below 90%. Desaturation was more common in patients with
pregnancy-related hypertension (22% versus 7%, p = 0.0021).
There were two cases (1%) of failed intubation with supraglottic
airway rescue, no emergency front of neck surgical access was
required, and there were no deaths.
Table III: Airway assessment and management
Provider demographic
details: Frequency Percentage (%) n
Level of qualification
Intern 4 2
Community service doctor 7 3.5
Medical officer 66 33 200
Registrar 111 55.5
Consultant 12 6
Years of experience
< 1 year 21 10.5
2001–5 years 130 65
> 5 years 49 24.5
Airway assessment:
Mallampati
I 44 22
200
II 95 47.5
III 48 24
IV 9 4.5
Not assessed 4 2
Dentition
Full 155 77.5
200
Partial present 36 18
Partial absent 7 3.5
Edentulous 2 1
Thyromental distance
≥ 6.5 cm or 4 fingers 150 75.4
199< 6.5 cm or 4 fingers 15 7.5
Not assessed 34 17.1
Inter-incisor gap
≥ 5 cm or 3 fingers 170 85
200< 5 cm or 3 fingers 19 9.5
Not assessed 11 5.5
Neck mobility
≥ 35 degrees 171 85.5
200< 35 degrees 1 0.5
Not assessed 28 14
Mandibular protrusion
Class A 89 44.7
199
Class B 12 6
Class C 3 1.5
Not assessed 95 47.7
Airway management:
Primary strategy
GA + ETT 144 72
200
GA + SGA 4 2
Neuraxial 48 24
Other 4 2
Muscle relaxant
None 4 2
200
Suxamethonium 194 97
Rocuronium 2 1
Cisatracurium - -
Other - -
Laryngoscope blade
Macintosh 3 122 61.3
199
Macintosh 4 24 12.1
CMAC 3 27 13.6
CMAC 4 19 9.5
CMAC D 4 2
None 3 1.5
Direct C-L view
Grade I 155 77.5
200
Grade IIa 25 12.5
Grade IIb 12 6
Grade III 4 2
Grade IV - -
Not assessed 4 2
Airway oedema
Absent 167 83.5
200Mild 28 14
Severe 5 2.5
Intubation attempts
1 174 87
200
2 25 12.5
3 1 0.5
4 - -
Introducer
Yes 41 20.5 200
No 159 79.5
Videolaryngoscope used
Yes 56 28 200
No 144 72
Supraglottic device used
Yes 2 1 200
No 198 99
Front of neck access
Yes - - 200
No 200 100
SpO2 nadir
< 90% 23 11.5 200
> 90% 177 88.5
GA – general anaesthesia, ETT – endotracheal tube, SGA – supraglottic airway, C-L – Cormack-
Lehane

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Implementation and initial validation of a multicentre obstetric airway management registry
Discussion
The primary outcome of this analysis showed that 80% of ob-
stetric GA cases performed during September 2018 and January
2019 at GSH, MMH and NSH were captured in the ObAMR by
means of an online data-capturing tool. This begins to address
the scarcity of airway-specic registry data for obstetric GA in the
literature.
On airway assessment, we encountered a high prevalence
of factors predicting dicult tracheal intubation. Clinically
signicant hypoxaemia (saturation nadir < 90%) occurred
in approximately one in eight patients (12%) and was more
common in patients with hypertensive disorders of pregnancy.
The overall incidence of hypoxaemia is similar to that described
in a recent observational study conducted elsewhere in South
Africa (16.8%).17
Neuraxial anaesthesia oers advantages in obstetric patients in
terms of avoidance of airway management.18 Over the past 20
years, there has been a signicant reduction in the use of GA for
caesarean section, with corresponding increased use of neuraxial
techniques.19 The challenges surrounding safe and timely se-
curing of the airway in the obstetric patient are a major cause
of morbidity and mortality in any setting.19 In 38 (19%) patients
in our study, the primary indication for GA was failed neuraxial
anaesthesia. This highlights an area for quality improvement in
our setting.
Airway diculty has been reported to be eight times more
common in obstetric patients compared to the general sur-
gical population,7 with the incidence of dicult or failed
tracheal intubation remaining at 2.6 (95% CI 2.0–3.2) per
1 000 anaesthetics (1 in 390) for obstetric general anaesthesia.7
Maternal mortality from failed intubation is 2.3 (95% CI 0.3–8.2)
per 100 000 of all GAs for caesarean section (one death per 90
failed intubations),7 and occurs from hypoxaemia secondary to
airway obstruction or oesophageal intubation, or pulmonary
aspiration.4,7 In this analysis, there were two cases of failed
intubation (1%) with successful supraglottic airway rescue, and
no emergency front of neck surgical access was required. There
were no maternal deaths recorded in the registry.
Most airway catastrophes occur when airway diculty is not
anticipated prior to induction of anaesthesia.5 Timely evaluation
of the parturient’s airway and adequate preparation to deal with
potential complications are helpful in avoiding airway disasters.
There are a few simple preoperative bedside clinical tests that can
be performed to evaluate the airway, including the Mallampati
score, mouth opening (inter-incisor gap), thyromental distance,
neck mobility (atlanto-occipital extension), and ability to pro-
trude the mandible.5,20,21 The relationship between increased
grades of airway classication and relative diculty of intubation
in parturients undergoing caesarean delivery during GA, has
been studied by Rocke et al.22 They found that the relative risk
of dicult intubation in a parturient with a Mallampati class 3
airway was 7.58 times higher than in a parturient with a class
1 airway. This relative risk increased to 11.3 in patients with
a class 4 airway.22 We encountered Mallampati grade 3 or 4 in
29% of cases, and mouth opening, thyromental distance and
mandibular protrusion were often limited.
Maternal, fetal, surgical and situational factors contribute to the
increased incidence of failed intubation. Many physiological
changes occur during pregnancy, including physical character-
istics such as increased BMI, breast enlargement, and generalised
oedema. The mucosa of the upper respiratory tract also becomes
more vascular and oedematous, especially during labour,23
leading to increased risk of airway bleeding and swelling.20
Fluid retention in head and neck tissues during pregnancy
potentially narrows the upper airway and reduces compliance,
making laryngoscopy more dicult.19 Clinical teaching is that
pharyngeal oedema may be exacerbated by preeclampsia and
eclampsia, although there is limited literature to support this
statement. In this analysis mild or severe airway oedema was
encountered in 17% of patients. Videolaryngoscopy (VL) has
been suggested as a useful adjunct for both anticipated and
unanticipated diculty in obstetric GA. The low rates of usage
of VL and tracheal tube introducers in our registry (despite near-
ubiquitous availability) is cause for concern, and an obvious
target for quality improvement.
There were several limitations of our study. The overall rate of
capture of approximately 80% into the registry reects that at
least 20% of general anaesthesia cases were omitted. However,
if the elevation of the capture rate due to the documentation
practice at MMH is excluded, the rate may have been only 71%. It
is unlikely that any category of airway challenge would have had
a higher likelihood of reporting or omission, so that selection
bias probably did not inuence the outcome. Although the
registry is rapidly completed by the attending anaesthetist,
it is possible that periods of high case load may have reduced
reporting. The ethical considerations concerning anonymity
precluded our establishing the clinical circumstances of the
cases not captured. Every attempt will be made to increase the
capture rate, by emphasising the long-term benets to patient
safety of maintaining a complete registry. The anaesthesia
provider during the GA was responsible for capturing the data
onto the ObAMR, and data entry errors may have occurred. The
online data capturing tool included denitions and pictures as a
guideline, but certain data elds including preoperative airway
assessment are subject to inter-observer variability. As clinicians
were ultimately responsible for the GA technique, there may
have been non-standardised performance. It was therefore
often dicult to identify the contributing factors for the high
incidence of hypoxaemia in our study.
Strengths of our study include the successful establishment of
the ObAMR, which we believe to be the rst online database
collecting information on airway management in the pregnant
population in our setting. The aims of this registry are to enhance
quality control and clinical governance, and to monitor and
assess airway management trends during GA in this high-risk
group of patients.

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South Afr J Anaesth Analg 2020; 26(4) http://www.sajaa.co.za
Implementation and initial validation of a multicentre obstetric airway management registry
The results of this initial analysis show that our online data-
capturing tool is valuable for collecting information on airway
management in the obstetric population. Hypoxaemia during
GA for obstetric patients is still common. This registry will allow
for broader analysis to be conducted on larger datasets and serve
as the basis for the performance of future interventional studies.
Acknowledgements
The authors would like to thank their colleagues in the
Department of Anaesthesia and Perioperative Medicine of
the University of Cape Town for collecting ObAMR data, and
our patients for consenting to participate and expand medical
knowledge.
Conflict of interest
The authors declare that they have no conicts of interest.
Funding source
This research did not receive any specic grant from funding
agencies in the public, commercial, or non-prot sectors.
Ethics approval
A multicentre Obstetric Airway Management Registry (ObAMR)
was established after approval by the Human Research Ethics
Committee (HREC) of the Health Sciences Faculty of the
University of Cape Town (UCT) (HREC Ref: R025/2018).
ORCID
MI Smit https://orcid.org/0000-0003-2323-0223
C van Tonder https://orcid.org/0000-0002-8223-1579
L du Toit https://orcid.org/0000-0003-0146-4002
D van Dyk https://orcid.org/0000-0001-8579-007X
AR Reed https://orcid.org/0000-0002-4033-3630
RA Dyer https://orcid.org/0000-0001-6475-0140
R Hofmeyr https://orcid.org/0000-0002-9990-7459
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associated with difficult intubation in obstetric anesthesia. Anaesthesiology.
1992:67-73.
23. Kodali B-S, Chandrasekhar S, Bulich LN, Topulos GP, Datta S. Airway changes
during labor and delivery. Anaesthesiology. 2008:357-362. https://doi.
org/10.1097/ALN.0b013e31816452d3.
Appendix 1 on next page

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Obstetric Airway Management Registry
Thank you for completing this Obstetric Airway Management Registry (ObAMR). The data below should form part of
your standard pre-operative assessment and peri-induction anaesthetic documentation, and should take 1-2 minutes
per case to complete. Should you have questions, please contact Dr Maretha Smit (76177) or A/Prof Ross Hofmeyr
(77392).
Please complete the survey below.
Case information
1) Location GSH MK (Maternity Centre)
GSH (Main Theatres)
MMH (Mowbray Maternity)
NSH (Somerset Hospital)
MPH (Mitchells Plain Hospital)
2) Date
__________________________________
3) What is your level of qualification? Intern
Community service
Medical Officer
Registrar
Consultant
4) Years of anaesthesia experience? < 1 Year
1 - 5 Years
> 5 Years
5) Consent for use of data in registry Simple verbal consent obtained
Patient unable* to provide sufficient verbal
consent. Please flag for follow-up.
(*Decreased level of consciousness etc)
Patient demographics
6) Age of patient in years
__________________________________
7) Height of patient in centimeters (actual or
estimated) __________________________________
8) Body weight of patient in kilograms (actual or
estimated) __________________________________
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Obstetric history
9) Gravidity of patient
__________________________________
10) Parity of patient
__________________________________
11) Current gestational age in weeks
__________________________________
12) Hypertensive disease None
Chronic hypertension
Pregnancy induced hypertension
Pre-eclampsia
Pre-eclampsia superimposed on chronic hypertension
Eclampsia
13) Duration of labour Not in labour
First stage (latent phase): from the onset of
contractions to 3cm dilatation of the cervix
First stage (active phase): from 3cm to full
cervical dilatation
Second stage: from complete dilation and
effacement to delivery of the baby
Third stage: from delivery of baby to delivery of
placenta
Fourth stage: the first hour after delivery
Within 48 hours post delivery
More than 48 hours post delivery
Anaesthetic Preassessment
14) Primary anaesthetic strategy Neuraxial
GA + mask ventilation
GA + mask + supraglottic device
GA + mask + endotracheal tube
Other
15) Indication for general anaesthesia Coagulopathy
Inadequate neuraxial anaesthesia
Prolonged case
Decreased level of consciousness
Other
16) Mallampati score Class I
Class II
Class III
Class IV
Not assessed

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17) Dentition Full
Partial - Most teeth present
Partial - Most teeth absent
Edentulous
18) Thyromental distance* ≥ 6,5cm or four fingers
< 6,5cm or four fingers
Not assessed
(*The distance from the chin to the notch of the
thyroid cartilage)
19) Mouth opening (inter-incisor gap) ≥ 5cm or three fingers
< 5cm or three fingers
Not assessed
20) Neck mobility* (atlanto-occipital extension) ≥ 35 degrees from neutral head position
< 35 degrees from neutral head position
Not assessed
(*The range of extension of the head over the
neck)
21) Mandibular protrusion Class A - the lower incisors can be protruded
anterior to the upper incisors
Class B - the lower incisors can be brought edge
to edge with the upper incisors but not anterior
to them
Class C - the lower incisors cannot be brought
edge to edge with the upper incisors
Not assessed
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Airway Management
22) Muscle relaxant used? None
Suxamethonium
Rocuronium
Cisatracurium
Other
23) Video laryngoscope immediately available? Yes
No
24) Video laryngoscope used for intubation? Yes
No
25) Intubation recorded on CMAC? Yes
No
26) Patient positioning optimal* for intubation Yes
No
(*Ramped/sniffing/ear-to-sternal notch
positioning)
27) Laryngoscope blade used Macintosh 3
Macintosh 4
CMAC 3
CMAC 4
CMAC D-blade
28) Direct Cormack-Lehane view of the glottis Grade I - 50% or more of vocal cords visible
Grade IIa - Less than 50% of vocal cords visible
Grade IIb - Only arytenoid cartilages visible
Grade III - Only the epiglottis is visible
Grade IV - Epiglottis not visible
Not assessed

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29) Upper airway oedema? Absent
Mild
Severe
30) Intubation attempts 1
2
3
4
5
> 5
31) SpO2 nadir*
__________________________________
(*lowest oxygen saturation during induction and
airway management (%))
32) Introducer (bougie or stylet) used? Yes
No
33) Supraglottic rescue (LMA or other) required? Yes
No
34) Surgical airway rescue (front-of-neck access) Yes
required? No