Tag Archives: RSI

Etomidate & sepsis

A meta-analysis attempts to quantify etomidate’s effect on mortality and adrenal suppression. Of course, we all know a meta-analysis can only be as reliable as the original data it’s analysing. I think editorialists Lauzier and Turgeon have a point with their statement:

“Given the widespread use of etomidate in the emergency room, we believe that a RCT designed to evaluate the safety of etomidate as a hypnotic agent for endotracheal intubation of patients with sepsis is not only ethical but also urgently warranted”

For a critique of the paper and subsequent discussion, check out the Academic Life in EM blog post by Brian Hayes

OBJECTIVE: To evaluate the effects of single-dose etomidate on the adrenal axis and mortality in patients with severe sepsis and septic shock.

DESIGN: A systematic review of randomized controlled trials and observational studies with meta-analysis.

SETTING: Literature search of EMBASE, Medline, Cochrane Database, and Evidence-Based Medical Reviews.

SUBJECTS: Sepsis patients who received etomidate for rapid sequence intubation.


MEASUREMENTS AND MAIN RESULTS: We conducted a systematic review of randomized controlled trials and observational studies with meta-analysis assessing the effects of etomidate on adrenal insufficiency and all-cause mortality published between January 1950 and February 2012. We only examined studies including septic patients. All-cause mortality served as our primary end point, whereas the prevalence of adrenal insufficiency was our secondary end point. Adrenal insufficiency was determined using a cosyntropin stimulation test in all studies. We used a random effects model for analysis; heterogeneity was assessed with the I statistic. Publication bias was evaluated with Begg’s test. Five studies were identified that assessed mortality in those who received etomidate. A total of 865 subjects were included. Subjects who received etomidate were more likely to die (pooled relative risk 1.20; 95% confidence interval 1.02-1.42; Q statistic, 4.20; I2 statistic, 4.9%). Seven studies addressed the development of adrenal suppression associated with the administration of etomidate; 1,303 subjects were included. Etomidate administration increased the likelihood of developing adrenal insufficiency (pooled relative risk 1.33; 95% confidence interval 1.22-1.46; Q statistic, 10.7; I2 statistic, 43.9%).

CONCLUSIONS: Administration of etomidate for rapid sequence intubation is associated with higher rates of adrenal insufficiency and mortality in patients with sepsis.

Etomidate is associated with mortality and adrenal insufficiency in sepsis: A meta-analysis Crit Care Med. 2012 Nov;40(11):2945-53

Intubation of the critically ill in Scotland

Hi folks! Cliff has given me the helm of his blogsite for this week whilst he is teaching prehospital and critical care ultrasound with the Americans at Castlefest 2012
He invited me to write an article on this latest paper in British Journal of Anaesthesia on Scottish ICU audit of emergency tracheal intubation. For those who don’t know, Cliff has a proud Scottish heritage and this paper is a useful audit of his home land’s performance of this critical care intervention. I have done airway audits and this one is quite a reasonable 4 month effort albeit not every ICU in Scotland participated, which is not unusual for those wanting to do these kind of audits. Airway management gets a bit personal and some find review of their emergency airway performance to be confronting. It should not be. Now it’s a fine distinction but its important to be clear on this. A FAILED AIRWAY DOES NOT MEAN YOU ARE A FAILURE!! FAILED OXYGENATION IS ANOTHER STORY….
There are always recurring themes from audits like these and I will highlight a few.
The first and foremost, is the absolutely essential role of capnography for tracheal tube confirmation and monitoring of airway patency and ventilator status. My FDEAR aeromedical intubation audit showed this was an issue of patient safety that should be improved.
This Scottish ICU study revealed that capnography was used in only 54% of emergency intubations despite the vast majority being in hospital locations where such monitoring is available! This is a recurring theme amongst emergency airway audits and coroners reports like this one.
Paradoxically this Scottish audit had a high number of intubating doctors with greater than 24 months of anaesthetic training and one hypothesis I have is that as doctors become more confident in emergency intubations, perhaps less reliance is felt required on monitoring like capnography? In human factors research into anaesthetic related crises, we call this the invulnerability or superman complex : “If I say the tube has gone in, I must be right!”
Secondly, the length of anaesthetic training of the intubating doctor appeared related to overall airway success rates and a low complication rate. There was only one surgical airway required over the 4 month period and 794 recorded intubations. The authors discuss though the potential problems that may face up and coming critical care doctors in the United Kingdom who may not be exposed to terms of anaesthetic training of up to 2 years. My own personal view is that it does not and should not matter where you get your emergency airway training but it should be structured and specific to the work that you are going to do. Learning to do epidural anaesthesia in laboring women might not be so helpful for the bilateral pneumonia swine flu patient with a BMI of 50! And certainly no point learning to use airway equipment that you will rarely or never have available where you normally work!
Thirdly and I find this fascinating having heard talks and debates on this topic by Dr Scott Weingart and Dr Paul Mayo, but in this Scottish paper of bloody sick patients needing intubation, 8% were performed without paralytics at all and overall intubation success and number of attempts were not significantly different compared to the paralytic assisted group. My view is that overall in critically ill patients , paralytics are your friend as these folks need the airway secured, one way or another. However this paper and Dr Mayo’s work certainly demonstrate that sedation only intubation is successful and is a reasonable alternative.
Finally, 61% of these emergency intubations utilized propofol and there was an association with post intubation hypotension (systolic <70mmHg). Ketamine use was low at 3% and I think this just reflects the greater anaesthetic training of the doctors in the study. I am aware Cliff has done a previous podcast rant on Propofol assasins
I don’t want to rant and am not as good at it as Cliff. BUT Choose your poison carefully! This paper reminds us what we all know. The milk of amnesia has issues! Ask the Jackson family!
Anyway that’s enough for this paper. I gotta pick myself off the floor again after listening to Cliff’s propofol rant..
– Dr Minh Le Cong, Royal Flying Doctor Service, Australia

BACKGROUND: Complications associated with tracheal intubation may occur in up to 40% of critically ill patients. Since practice in emergency airway management varies between intensive care units (ICUs) and countries, complication rates may also differ. We undertook a prospective, observational study of tracheal intubation performed by critical care doctors in Scotland to identify practice, complications, and training.
METHODS: For 4 months, we collected data on any intubation performed by doctors working in critical care throughout Scotland except those in patients having elective surgery and those carried out before admission to hospital. We used a standardized data form to collect information on pre-induction physical state and organ support, the doctor carrying out the intubation, the techniques and drugs used, and complications noted.
RESULTS: Data from 794 intubations were analysed. Seventy per cent occurred in ICU and 18% occurred in emergency departments. The first-time intubation success rate was 91%, no patient required more than three attempts at intubation, and one patient required surgical tracheostomy. Severe hypoxaemia ( <80%) occurred in 22%, severe hypotension (systolic arterial pressure <80 mm Hg) in 20%, and oesophageal intubation in 2%. Three-quarters of intubations were performed by doctors with more than 24 months formal anaesthetic training and all but one doctor with <6 months training had senior supervision.
CONCLUSIONS: Tracheal intubation by critical care doctors in Scotland has a higher first-time success rate than described in previous reports of critical care intubation, and technical complications are few. Doctors carrying out intubation had undergone longer formal training in anaesthesia than described previously, and junior trainees are routinely supervised. Despite these good results, further work is necessary to reduce physiological complications and patient morbidity.

Tracheal intubation in the critically ill: a multi-centre national study of practice and complications
Br J Anaesth. 2012 May;108(5):792-9

Extubation guidelines

Tracheal extubation is a high risk procedure in anaesthesia and critical care. Until now most guidelines have focused on intubation, with little to guide the process of extubation. Complications may relate to the following issues:

  • Exaggerated reflexes – laryngospasm (which can lead to both hypoxia and negative pressure pulmonary oedema) and bronchospasm
  • Reduced airway reflexes
  • Dysfunctional laryngeal reflexes
  • Depletion of oxygen stores at extubation
  • Airway injury
  • Physiological compromise in other systems
  • Human factors

The goal is to ensure uninterrupted oxygen delivery to the patient’s lungs, avoid airway stimulation, and have a back-up plan, that would permit ventilation and re-intubation with minimum difficulty and delay should extubation fail.
The Difficult Airway Society has now published guidelines for the management of tracheal extubation, describing four steps:

Step 1: plan extubation.

Step 2: prepare for extubation.

Step 3: perform extubation.

Step 4: post-extubation care: recovery and follow-up.

During step 3, emphasis is on pre-oxygenation, positioning, and suction. This is followed by simultaneous deflation of the tracheal tube cuff and removal of the tube at the peak of a sustained inflation. This generates a passive exhalation, which may assist in the expulsion of secretions and possibly reduce the incidence of laryngospasm and breathholding.
The guideline refers to low-risk and at-risk extubations. ‘Low-risk’ (routine) extubation is characterised by the expectation that reintubation could be managed without difficulty, if required. ‘At-risk’ means the presence of general and/or airway risk factors that suggest that a patient may not be able to maintain his/her own airway after removal of the tracheal tube. ‘At-risk’ extubation is characterised by the concern that airway management may not be straightforward should reintubation be required.
These guidelines are written for the peri-operative patient but the text contains some interesting points that are pertinent to the ED or ICU patient. Some simple algorithms are presented:

Difficult Airway Society Guidelines for the management of tracheal extubation
Anaesthesia. 2012 Mar;67(3):318-40 Free full text

More guidelines from the Difficult Airway Society

Australasian ED Airway Registry

Managing the emergency airway is one of the most important and risky things we do. We have a responsibility to record, monitor, report and improve our performance.
In the US, the National Emergency Airway Registry has been running for over a decade and has significantly contributed to our airway knowledge base.
In the UK, the NAP4 audit provided fascinating and scary insight into complications of emergency airway management.
Pre-hospital registries have been developed, like Minh Le Cong’s Flying Doctor Emergency Airway Registry; and many of us are now contributing to the Airway Management Study in Physician Manned Helicopter Emergency Medical Services (AIRPORT) study.
Now there is an opportunity for Australasian emergency departments to contribute to a national audit.
Dr Toby Fogg FACEM, emergency physician at Royal North Shore Hospital in Sydney, who began the registry, explained in a recent Life in The Fast Lane response:

I have been running an airway registry in the ED at The Royal North Shore Hospital in Sydney for the last 2 years.

I presented the first 18 months of data at the ASM in Sydney last year and I must admit, they showed room for improvement!.

One of the many things we have subsequently done is introduced a Pre Intubation Checklist which I have published, along with our preliminary findings, at www.airwayregistry.org.au.

I am happy for people to download the file and use it as is, or with appropriate modifications.

Furthermore I would love to hear from anyone keen to undertake an Airway Registry in their own ED — a PDF of the data collection form we use is also on the website.

As the authors of the NAP4 study conclude, it is essential we all audit our practice of this potentially high risk procedure.

Dr Toby Fogg uses his C-MAC video laryngoscope to demonstrate the audit form

Background: Successful airway management is one of the cornerstones of care for critically ill or injured patients in the Emergency Department (ED). The risks of intubation are known to be higher in this environment than in the operating theatre (OT) yet there are no published data on airway management in an Australian ED.

Objectives: To describe the practice of intubation in the ED of a tertiary hospital in Australia, with particular emphasis on the number of attempts, adjuncts used, the seniority of staff involved and the rate of complications.

Methods: A prospective, observational study.

Results: Over the 18-month study period, 295 episodes of intubation occurred with a total of 345 attempts. Consultant supervision occurred in 69.8% of cases, registrars made the first attempt at intubation in 57.5% and SRMOs in 31.0% of the patients. 83.7% of the patients were intubated at the first pass with a further 13.0% intubated one the second attempt. This leaves 10 patients (3.4%) that required ≥3 attempts, 4 (1.4%) ≥4 attempts and 1 (0.4%) required a 5th attempt. Difficult laryngoscopy, as defined by Cormack and Lehane grade III or IV, occurred in 24% of the first attempts. Bougies were used in 36% of attempts, whilst a stylet in 35%. Video laryngoscopy was used in 47.5% of attempts. Complications occurred in 28%.

Discussion: The success rate within two attempts is comparable to the anaesthetic literature, and although high, the rate of complications is comparable to data from EDs overseas. The rate of difficult laryngoscopy, however, is surprisingly high. The study has prompted a significant review of airway training and management within the ED at Royal North Shore Hospital and the results of the interventions will be monitored.

The Royal North Shore Hospital Emergency Department Airway Registry. A Prospective Observational Study of Airway Management in a Tertiary Hospital Emergency Department in Sydney, Australia
Annesley N,Vassiliadis J, Kerry Hitos K, Fogg T
Emerg. Med. Australas. 24 (Suppl. 1):27-28

Study authors Toby Fogg and Nick Annesley demonstrate the 'Happiness Triad'

Airway lessons relearned

A UK study examined all out-of-operating room intubations over a one month period in nine hospitals1.
Patients whose indication for tracheal intubation was cardiac arrest and who were intubated without the use of drugs were excluded from analysis, as were neonatal intubations.
Disappointing – but not surprising – findings were the lack of universally applied capnography and the use of propofol as the most commonly used induction agent. However more senior intubators were less likely to use propofol than more junior ones (who used it in 93% of intubations!), and the seniors were also more likely to use non-depolarising neuromuscular blocking drugs (NMBDs) than juniors.
The authors report that in seven (4%) patients, pre-oxygenation “was felt to be impossible“. I find it hard to imagine this situation unless RSI is being done on combative patients without prior sedation, which if this is the case makes me shudder.
The authors express their understandable concern over the absence of an alternative airway such as a laryngeal mask in 12% of cases.
Although the adverse event rate seems high, they point out that they used the term ‘adverse events’ rather than ‘complications’ as the events may not be directly attributable to the intubation. In other words, some patients may have been hypoxaemic or hypotensive to start with due to their underlying clinical problem.
I find this study interesting because the results are similar to those reported in a study I and my colleagues conducted a decade ago2, in which ICU intubations were shown to be more hazardous that ED intubations. This can be explained by the higher proportion of patients on ICU with shock and/or respiratory failure. On the other hand, ED patients more commonly required intubation for neurological presentations, with relatively stable cardiorespiratory physiology.
Take a look at the breakdown of cases in the recent study:

and compare this with our findings:

…this is why I have to argue when I hear it occasionally stated that ‘all ED airways are difficult airways’ – some are actually easy, in patients with long stable apnoea times who make great teaching cases.
The authors “speculate that the low rate of hypoxaemia and airway complications may be related to the high proportion of intubations undertaken by those with anaesthesia as a base speciality, and to the almost universal use of NMBDs.” They do not provide strong data to support the first half of their statement. The supplementary data available online indeed show that the majority of intubators were anaesthesia-based, but how their adverse event rates compare with those of the emergency physicians and paediatricians who also undertook intubations is not available.
I don’t want to detract from the important message Dr Bowles and colleagues are conveying: that the lessons from the 4th National Audit Project on major complications of airway management in the UK still need to be applied.
This paper is one aspect of the potentially life-saving work done by this team, which includes the intubation checklist they created.

BACKGROUND: Tracheal intubation is commonly performed outside the operating theatre and is associated with higher risk than intubation in theatre. Recent guidelines and publications including the 4th National Audit Project of the Royal College of Anaesthetists have sought to improve the safety of out-of-theatre intubations.

METHODS: We performed a prospective observational study examining all tracheal intubations occurring outside the operating theatre in nine hospitals over a 1 month period. Data were collected on speciality and grade of intubator, presence of essential safety equipment and monitoring, and adverse events.

RESULTS: One hundred and sixty-four out-of-theatre intubations were identified (excluding those where intubation occurred as part of the management of cardiac arrest). The most common indication for intubation was respiratory failure [74 cases (45%)]. Doctors with at least 6 month’s experience in anaesthesia performed 136 intubations (83%); consultants were present for 68 cases (41%), and overall a second intubator was present for 94 procedures (57%). Propofol was the most common induction agent [124 cases (76%)] and 157 patients (96%) received neuromuscular blocking agents. An airway rescue device was available in 139 cases (87%). Capnography was not used in 52 cases (32%). Sixty-four patients suffered at least one adverse event (39%) around the time of tracheal intubation.

CONCLUSIONS: Out-of-theatre intubation frequently occurs in the absence of essential safety equipment, despite the existing guidelines. The associated adverse event rate is high.

1. Out-of-theatre tracheal intubation: prospective multicentre study of clinical practice and adverse events
Br J Anaesth. 2011 Nov;107(5):687-92

BACKGROUND: Emergency rapid sequence intubation (RSI) performed outside the operating room on emergency patients is the cornerstone of emergency airway management. Complication rates are unknown for this procedure in the United Kingdom and the factors contributing to immediate complications have not been identified.

AIMS: To quantify the immediate complications of RSI and to assess the contribution made by environmental, patient, and physician factors to overall complication rates.

METHODS: Prospective observational study of 208 consecutive adult and paediatric patients undergoing RSI over a six month period.

RESULTS: Patients were successfully intubated by RSI in all cases. There were no deaths during the procedure and no patient required a surgical airway. Patient diagnostic groups requiring RSI are described. Immediate complications were hypoxaemia 19.2%, hypotension 17.8%, and arrhythmia 3.4%. Hypoxaemia was more common in patients with pre-existing respiratory or cardiovascular conditions than in patients with other diagnoses (p<0.01). Emergency department intubations were associated with a significantly lower complication rate than other locations (16.9%; p = 0.004). This can be explained by the difference in diagnostic case mix. Intubating teams comprised anaesthetists, non-anaesthetists, or both. There were no significant differences in complication rates between these groups.
CONCLUSIONS: RSI has a significant immediate complication rate, although the clinical significance of transient events is unknown. The likelihood of immediate complications depends on the patient’s underlying condition, and relevant diagnoses should be emphasised in airway management training. Complication rates are comparable between anaesthetists and non-anaesthetists. The significantly lower complication rates in emergency department RSI can be explained by a larger proportion of patients with comparatively stable cardiorespiratory function.

2. The who, where, and what of rapid sequence intubation: prospective observational study of emergency RSI outside the operating theatre
Emerg Med J. 2004 May;21(3):296-301 Free Full Text

Steroid replacement after etomidate: no benefit

More fuel for the etomidate debate…
In essence:

  • Etomidate has been a useful induction agent for RSI for many years due to its greater haemodynamic stability compared with thiopentone or propofol
  • It is widely used in the USA
  • It inhibits the 11β-hydroxylase enzyme that converts 11β-deoxycortisol into cortisol in the adrenal gland
  • A single dose of etomidate has been demonstrated to inhibit cortisol production for up to 48 hrs
  • This has led to concerns about its use in the critically ill, particular in patients with severe sepsis / septic shock
  • This small study randomised patients receiving etomidate to hydrocortisone or placebo, with no significant difference in these patient-oriented outcomes: duration of mechanical ventilation, intensive care unit length of stay, or 28-day mortality
  • This study suggests that replacement doses of hydrocortisone are not required after a single dose of etomidate
  • No randomised study has conclusively demonstrated increased mortality due to etomidate; however while controversy and the possibility of harm remain, I personally see no reason not to use ketamine for RSI in haemodynamically compromised patients.
  • Ketamine was compared with etomidate in a previous controlled trial

OBJECTIVE: To investigate the effects of moderate-dose hydrocortisone on hemodynamic status in critically ill patients throughout the period of etomidate-related adrenal insufficiency.

DESIGN: Randomized, controlled, double-blind trial (NCT00862381).

SETTING: University hospital emergency department and three intensive care units.

INTERVENTIONS: After single-dose etomidate (H0) for facilitating endotracheal intubation, patients without septic shock were randomly allocated at H6 to receive a 42-hr continuous infusion of either hydrocortisone at 200 mg/day (HC group; n = 49) or saline serum (control group; n = 50).

MEASUREMENTS AND MAIN RESULTS: After completion of a corticotrophin stimulation test, serum cortisol and 11β-deoxycortisol concentrations were subsequently assayed at H6, H12, H24, and H48. Forty-eight patients were analyzed in the HC group and 49 patients in the control group. Before treatment, the diagnostic criteria for etomidate-related adrenal insufficiency were fulfilled in 41 of 45 (91%) and 38 of 45 (84%) patients in the HC and control groups, respectively. The proportion of patients with a cardiovascular Sequential Organ Failure Assessment score of 3 or 4 declined comparably over time in both HC and control groups: 65% vs. 67% at H6, 65% vs. 69% at H12, 44% vs. 54% at H24, and 34% vs. 45% at H48, respectively. Required doses of norepinephrine decreased at a significantly higher rate in the HC group compared with the control group in patients treated with norepinephrine at H6. No intergroup differences were found regarding the duration of mechanical ventilation, intensive care unit length of stay, or 28-day mortality.

CONCLUSION: These findings suggest that critically ill patients without septic shock do not benefit from moderate-dose hydrocortisone administered to overcome etomidate-related adrenal insufficiency.

Corticosteroid after etomidate in critically ill patients: A randomized controlled trial
Crit Care Med. 2012 Jan;40(1):29-35

Make space for pre-hospital intubation

Control your environment – don’t let it control you” is a reliable adage for pre-hospital providers, and its adherence can assist in in-hospital resuscitation too. Commanding control of ones space is a skill demonstrated by more seasoned paramedics compared with novices and the requirement, where possible, for 360 degrees of access around a patient is included in some Standard Operating Procedures for pre-hospital rapid sequence intubation.

Brett Rosen MD controlling space in the field

Evidence for this approach is now further supported by a study demonstrating that limited surrounding space on scene was a significant risk factor for difficult pre-hospital intubation by European EMS physicians.
Other predisposing factors for difficult prehospital intubation included obesity and a short neck.

OBJECTIVES:For experienced personnel endotracheal intubation (ETI) is the gold standard to secure the airway in prehospital emergency medicine. Nevertheless, substantial procedural difficulties have been reported with a significant potential to compromise patients’ outcomes. Systematic evaluation of ETI in paramedic operated emergency medical systems (EMS) and in a mixed physician/anaesthetic nurse EMS showed divergent results. In our study we systematically assessed factors associated with difficult ETI in an EMS exclusively operating with physicians.

METHODS:Over a 1-year period we prospectively collected data on the specific conditions of all ETIs of two physician staffed EMS vehicles. Difficult ETI was defined by more than 3 attempts or a difficult visualisation of the larynx (Cormack and Lehane grade 3, or worse). For each patient ETI conditions, biophysical characteristics and factors of the surrounding scene were assessed. Additionally, physicians were asked whether they had expected difficult ETI in advance.

RESULTS:Out of 3979 treated patients 305 (7.7%) received ETI. For 276 patients complete data sets were available. The incidence of difficult ETI was 13.0%. In 4 cases (1.4%) ETI was impossible, but no patient was unable to be ventilated sufficiently. Predicting conditions for difficult intubation were limited surrounding space on scene (p<0.01), short neck (p<0.01), obesity (p<0.01), face and neck injuries (p<0.01), mouth opening<3cm (p<0.01) and known ankylosing spondylitis (p<0.01). ETI on the floor or with C-spine immobilisation in situ were of no significant influence. The incidence of unexpected difficult ETI was 5.0%.
CONCLUSIONS: In a physician staffed EMS difficult prehospital ETI occurred in 13% of cases. Predisposing factors were limited surrounding space on scene and certain biophysical conditions of the patient (short neck, obesity, face and neck injuries, and anatomical restrictions). Unexpected difficult ETI occurred in 5% of the cases.

Difficult prehospital endotracheal intubation – predisposing factors in a physician based EMS
Resuscitation. 2011 Dec;82(12):1519-24

Preoxygenation and Prevention of Desaturation

This paper is an excellent review article citing the cogent relevant evidence for optimal preoxygenation prior to RSI in the critically ill patient. The evidence has been interpreted with pertinent recommendations by two of the world’s heavy hitters in emergency medicine – Scott Weingart and Rich Levitan. If you can get a full text copy of the paper, laminate Figure 3 (‘Sequence of Preoxygenation and Prevention of Desaturation‘) and stick it to the wall in your resus bay!
The points covered include:

  • Why preoxygenate? Preoxygenation extends the duration of safe apnoea and should be considered mandatory, even in the crashing patient.
  • Standard non-rebreather facemasks set to the highest flow rate of oxygen possible should be used.
  • Allow 8 vital capacity breaths for co-operative patients or 3 minutes for everyone else.
  • Increasing mean airway pressure by CPAP/NIV or PEEP valves improves preoxygenation. However caution should be used in hypovolaemic shocked patients (decreased venous return) and should be reserved for patients who cannot preoxygenate >93-95% with high FiO2.
  • 20-degree head up or reverse Trendelenburg (in suspected trauma) improves pre oxygenation.
  • Apnoeic diffusion oxygenation can extend safe duration of apnoea after the RSI. Set nasal cannulae at 15L/min and leave on during intubation attempts. Ensure upper airway patency (ear to sternal notch and jaw thrust).
  • Active ventilation during onset of muscle relaxation should be assessed on a case by case basis and reserved for patients at high risk of desaturation (6-8 breaths per minute slowly, TV 6-7ml/kg).
  • If there is a high risk of desaturation rocuronium (1.2 mg/kg) may provide a longer duration of safe apnoea than suxamethonium with similar onset time.

Preoxygenation and Prevention of Desaturation During Emergency Airway Management
Ann Emerg Med. 2011 Nov 1. [Epub ahead of print]
[EXPAND Abstract]

Patients requiring emergency airway management are at great risk of hypoxemic hypoxia because of primary lung pathology, high metabolic demands, anemia, insufficient respiratory drive, and inability to protect their airway against aspiration. Tracheal intubation is often required before the complete information needed to assess the risk of periprocedural hypoxia is acquired, such as an arterial blood gas level, hemoglobin value, or even a chest radiograph. This article reviews preoxygenation and peri-intubation oxygenation techniques to minimize the risk of critical hypoxia and introduces a risk-stratification approach to emergency tracheal intubation. Techniques reviewed include positioning, preoxygenation and denitrogenation, positive end expiratory pressure devices, and passive apneic oxygenation.


Effect of physician specialty on pre-hospital intubation success

Researchers from the London Helicopter Emergency Medical Service describe the success of pre-hospital laryngoscopy according to the grade and specialty of the HEMS physician…

There is conflicting evidence concerning the role and safety of prehospital intubation, and which providers should deliver it. Success rates for physician-performed rapid sequence induction are reported to be 97-100%, with limited evidence of improved survival in some patient groups. However, there is also evidence that prehospital intubation and ventilation can do harm. Prospective data were recorded on the success of intubation, the quality of the laryngeal view obtained and the number of attempts at intubation. These data were then analysed by the grade of intubating doctor and whether the intubating doctor had a background in anaesthesia or emergency medicine. All groups had a similar success rate after two attempts at intubation. Doctors with a background in anaesthesia and consultant emergency physicians had a significantly better first-pass intubation rate than emergency medicine trainees. The quality of laryngeal view was significantly better in doctors with an anaesthetics background.

Success in physician prehospital rapid sequence intubation: what is the effect of base speciality and length of anaesthetic training?
Emerg Med J. 2011 Mar;28(3):225-9

Crike rate 1 in 500 in Scottish ED

A review of over 2500 intubation attempts in the emergency department1, (of which 1671 were rapid sequence intubation attempts) revealed five cricothyroidotomies, giving a crike rate of 0.2% which is much lower than in some other ED based registries. In four patients, predictors of difficult airway were identified before the endotracheal intubation attempt, and formal preparation for rescue surgical airway was performed. Three of the surgical airways were performed by emergency medicine trainees, one by an emergency medicine specialist and one by an ear, nose and throat specialist. There was a 100% success rate for placement of all surgical airways on the first attempt.

Four surgical airways were done in trauma patients: laryngeal fracture, facial burns, Le Fort II facial fracture and penetrating neck injury.
This study is of interest to UK emergency physicians who may be interested in Edinburgh Royal Infirmary’s collaborative approach to emergency airway management by the Departments of Emergency Medicine, Anaesthesia and Critical Care.
It is not possible to tell from this paper whether there were patients in whom surgical airway was indicated but not performed, and therefore in my view the ostensibly ‘good’ low rate of 0.2% should be viewed with interest rather than awe. Having said that, this figure is more in keeping with my own experience and expectation from UK/Australasian practice; it has been highlighted in the UK EM literature before2, including by myself3, that in our patient group good training and supervision should result in lower surgical airway rates than the ~1% often quoted.

OBJECTIVES: To determine the frequency of and primary indication for surgical airway during emergency department intubation.

METHODS: Prospectively collected data from all intubations performed in the emergency department from January 1999 to July 2007 were analysed to ascertain the frequency of surgical airway access. Original data were collected on a structured proforma, entered into a regional database and analysed. Patient records were then reviewed to determine the primary indication for a surgical airway.

RESULTS: Emergency department intubation was undertaken in 2524 patients. Of these, only five patients (0.2%) required a surgical airway. The most common indication for a surgical airway was trauma in four of the five patients. Two patients had attempted rapid sequence induction before surgical airway. Two patients had gaseous inductions and one patient received no drugs. In all five patients, surgical airway was performed secondary to failed endotracheal intubation attempt(s) and was never the primary technique used.

CONCLUSION: In our emergency department, surgical airway is an uncommon procedure. The rate of 0.2% is significantly lower than rates quoted in other studies. The most common indication for surgical airway was severe facial or neck trauma. Our emergency department has a joint protocol for emergency intubation agreed by the Departments of Emergency Medicine, Anaesthesia and Critical Care at the Edinburgh Royal Infirmary. We believe that the low surgical airway rate is secondary to this collaborative approach. The identified low rate of emergency department surgical airway has implications for training and maintenance of skills for emergency medicine trainees and physicians.

1. Surgical airway in emergency department intubation
Eur J Emerg Med. 2011 Jun;18(3):168-71
2. Rapid sequence induction in the emergency department: a strategy for failure.
Emerg Med J. 2002 Mar;19(2):109-13
3. RSI by non-anaesthetists in the UK – lower incidence of cricothyrotomy than in the US
EMJ e-letters 2002; 3 April