The difficult airway – a new perspective

This is a mirror of a post originally from

In the #FOAMed world there is a lot of talk about airway management – about difficult airwaysalgorithmsvortexapneic oxygenation techniques and much more.

In a recent paper in the Western Journal of Emergency Medicine, Mosier et. al. talk about the „physiologically difficult airway“ – a very good and nicely written perspective on airway management in the critical patient (full paper available for free here). It expands on topics already mentioned by (who else?) Scott Weingard a few years back.

Essentially, the authors say that a difficult airway not only consists of appreciating anatomical abnormalities but also identifying those conditions that create a high risk for patients to go into cardiac arrest because of airway management. Then they give recommendations how to deal with those situations.

The four „high risk airway management scenarios“ they mention are:

  • Hypoxia
  • Hypotension
  • Severe Metabolic Acidosis
  • Right ventricular failure

The recommendations from their paper are (all cited from Mosier et. al. The Physiologically Difficult Airway. Western Journal of Emergency Medicine 2015), I’m highlighting especially interesting parts.


1. Preoxygenation and apneic oxygenation should be performed in all critically ill patients. Despite mixed data, apneic oxygenation is a low-risk intervention that may provide signi cant bene t in prolonging the safe apneic period. If a HFNC system is not available, a wide-bore nasal cannula or standard nasal prongs should be used to augment preoxygenation and provide apneic oxygenation.
2. In patients with shunt physiology due to atelectasis or alveolar  lling from pneumonia, ARDS or pulmonary edema, NIPPV can improve alveolar recruitment and oxygenation. In select patients, supraglottic airways may be considered when higher pressures are needed or a mask seal with NIPPV cannot be achieved. One must balance this potential bene t of a supraglottic airway with the risk of aspiration or upper airway injury. Nasal continuous positive airway pressure with a nasal mask may be useful to maintain alveolar recruitment during intubation in patients at high risk.
3. For patients who cannot tolerate the NIPPV mask (e.g. delirium), analgesia, anxiolysis, or DSI may be considered to optimize preoxygenation. If procedural sedation for preoxygenation is performed, one must be prepared to intubate at the onset of DSI, even with ketamine, due risk of cardiac arrest, laryngospasm and apnea, which have all been reported with ketamine.


1. Patients with conditions that reduce venous return are particularly susceptible to hypotension and patients at risk are suggested by pre-intubation hypotension or an elevated shock index >0.8. These patients should be hemodynamically optimized prior to intubation. This includes aggressive volume resuscitation if the patient is likely to be a volume responder. Hemodynamically stable induction agents should be used when possible.
2. For patients unresponsive to volume resuscitation, a norepinephrine infusion should be initiated.
3. If pre-intubation resuscitation is not feasible due to impending cardiopulmonary arrest in patients with shock, peripherally administered vasopressor boluses can be prepared quickly at the bedside and may maintain blood pressure during intubation and resuscitation. This intervention has not been studied in critically ill adults; however, diluted epinephrine (given as 10-50mcg boluses with a concentration of 1-10mcg/ mL) may be preferred due to its inotropic effect.
4. For patients without shock who have a transient drop in blood pressure after intubation due to the vasodilatory effects of induction agents or transition to positive pressure ventilation, diluted phenylephrine (given as 50- 200mcg boluses with a concentration of 100mcg/mL) may be useful.

Severe metabolic acidosis:

1. Intubation should be avoided, if possible, in patients with severe metabolic acidosis who have a minute ventilation requirement not likely to be met by the mechanical ventilator, despite a low pH. A short trial of NIPPV may adequately support the respiratory work of breathing until correction of the underlying metabolic acidosis can occur and will provide an estimate of the patient’s intrinsic minute ventilation by measuring the patient’s respiratory rate and tidal volume delivered with each breath.
2. If intubation is necessary, maintaining spontaneous respiration becomes the critical action both during intubation and with mechanical ventilation. This will allow the patient to maintain their own high minute ventilation and includes using sedative agents that are less likely to reduce the patient’s respiratory drive. Rapid sequence intubation should be avoided if possible, and if one is deemed necessary, a short-acting neuromuscular blocker such as succinylcholine should be used.
3. After intubation, we recommend choosing a ventilator mode that allows the patient to set and maintain their own minute ventilation in order to best maintain their respiratory compensation. A pressure-targeted ventilator mode such as pressure support ventilation or pressure control mode will allow the patient to set the rate and tidal volume received. Special care should be taken to monitor for air trapping given the high rates and tidal volumes reached as well as monitor for respiratory muscle fatigue, which will result in a loss of compensation.

Right heart failure

1. Bedside echocardiographic assessment of RV function should be performed to assess RV dysfunction versus RV failure. If the patient has some contractile reserve (RV dysfunction), cautious  uid resuscitation should be performed.
2. Preoxygenation is essential despite the dififculties resulting from intracardiac shunt and ventilation-perfusion (V/Q) mismatch, which commonly occur in right heart failure.
3. Apneic oxygenation should be performed given the potential for benefit. INO (intranasal nitric oxide) at low concentrations (<30ppm), delivered in-line continuously through the nasal cannula, can augment oxygenation by improving V/Q matching in the hypoxemic patient but may worsen V/Q mismatch at higher concentrations. In the RV failure patient without hypoxemia, 30-80ppm of iNO delivered
through the nasal cannula, or inhaled epoprostenol during preoxygenation and apneic oxygenation can reduce pulmonary vascular resistance.
4. Induction agents should be considered carefully. Hemodynamically neutral sedatives such as etomidate should be used for induction. Intravenous fentanyl premedication may be useful to blunt the hypertensive response to laryngoscopy.
5. Continuous norepinephrine infusion should be started prior to induction in hypotensive patients with the goal of increasing mean arterial pressure higher than pulmonary artery pressure, which can be determined by bedside echocardiography. For patients without hypotension, norepinephrine should be primed and “in-line” in the event of post intubation or sedative induced hypotension.
6. The goals of mechanical ventilation include maintenance of a low mean airway pressure and avoidance of hypoxemia, atelectasis, and hypercapnea, which increase RV afterload.
I highly recommend reading the whole paper, the different scenarios are very nicely explained and worked up.
What do you think about it? Do you concur with the recommendations?

German Prehospital Anesthesia Guidelines

Mirror of a post originally from

Recently, the German Society of Anesthesiology and Critical Care Medicine (DGAI) has published their first ever Recommendation on prehospital emergency anesthesia. Since in Germany there is a system with both paramedics (currently 2 years of training, just now „upgraded“ to 3 years) and a broad availability of prehospital emergency physicians on rapid response vehicles and helicopters (about 1.000 emergency vehicles in the country) often times, even complex airway management is done „in the field“.

So – what is the DGAI recommending?

The central points in the recommendations are:

  • Critical scrutiny of the indication to induct prehospital anesthesia
  • RSI with a standardized approach, standardized equipment and medications, in-line-stabilization (if needed), capnography
  • Preoxygenation via face-mask with reservoir or noninvasive ventilation (NIV)
  • Basic monitoring that needs to be there: ECG monitoring, automatic blood pressure, pulse oxymetry, capnography
  • If possible two venous accesses

Indications to induce prehospital anesthesia are:

  • Respiratory insufficiency (hypoxemia or hyper/hypoventilation) and contraindication or failure of noninvasive ventilation (NIV)
  • Reduced consciousness / neurologic deficit with risk of aspiration
  • Polytrauma / massive trauma with hemodynamic instability or hypoxia or suspicion of traumatic brain injury with GCS <9.

Goals of prehospital anesthesia are:

  • Amnesia
  • Anxiolysis
  • Reduction of stress
  • Analgesia
  • Effective airway protection
  • Reduction in Oxygen consumption
  • Protection of vital organs, reduction/prevention of secondary myocardial or cerebral damage

There is a lot of emphasis on preparation, team communication and team management.

Before starting with the „real“ RSI, there needs to be the indication and team communication. While preoxygenation is started, optimal positioning, preparation of medications, airway alternatives, suction and capnography as well as monitoring and two IV-accesses are prepared. Only then RSI is started. (There is no „checklist“ per se, as it is recommended in a few of the other online available airway algorithms, e.g. Sydney HEMS or EMcrit.

In the case of cannot ventilate / cannot intubate they suggest a „forward strategy“ since the option to return to spontaneous breathing is in preclinical emergency medicine – contrary to clinical anesthesia – mostly only a theoretical option.

Now to what I really like about this guideline – they managed to group prehospital patients into different scenarios and have suggestions for induction in all of them. Since we as prehospital emergency doctors treat such a broad range of patients, a „one size fits all“ concept does not always apply (the only exeption being of course Ketamine, which I love dearly ;-)).

I list their recommendations here – please feel free to discuss and offer your opinions! By the way – they to use S-Ketamin/Ketanest here (double potency of Ketamine), so don’t be surprised by the seemingly low doses of Ketamine. Also, they suggest push-dose-pressors of 10yg of Norepinephrine given with low blood pressure, or via continuous infusion.

Massive Trauma

Analgosedation until extrication is achieved (if needed):
Midazolam 3mg + S-Ketamin 25mg (every 10min rep bolus 10mg if needed)

Midazolam 7mg OR Propofol 100mg OR Thiopental 200mg
+ S-Ketamin 100mg OR Fentanyl 0,2mg OR Sufentanil 20yg
+ Rocuronium 70-100mg OR Succinylcholine 100mg

Midazolam 3-5mg (every 20mins)
+ S-Ketamin 20mg (every 20 mins) OR Fentanyl 0,15mg (every 20 mins)
+ Rocuronium 20mg (every 20min)

Isolated traumatic brain injury, stroke, intracranial hemmorhage

Thiopental 300mg or Propofol 140mg
+ Fentanyl 0,2mg OR Sufentanil 20yg OR S-Ketamin 100mg
+ Rocuronium 70-100mg OR Succinylcholine 70mg

Midazolam 3-5mg (every 20mins)
+ Fentanyl 0,15mg (every 20 mins)

High Risk Cardiac Patient – two cases with different suggestions

1.) Hypertensive pulmonary edema, hypoxemia, failure of NIV

Fentanyl 0,2mg OR Sufentanil 20yg iv
+ Etomidate 20mg
+ Rocuronium 70-100mg OR Succinylcholine 70mg

Midazolam 3-5mg (every 20mins)
+ Fentanyl 0,1mg (every 20 mins)

2.) Cardiogenic shock, hypotensive, hypoxemia

Fentanyl 0,2mg OR Sufentanil 20yg iv
+ Midazolam 7mg
+ Rocuronium 70-100mg OR Succinylcholine 70mg

Midazolam 3-5mg (every 20mins)
+ Fentanyl 0,1mg (every 20 mins)

Respiratory insufficiency

Version 1:

Fentanyl 0,2mg OR Sufentanil 20yg iv
+ Propofol 110-160mg or Etomidate 20mg
+ Rocuronium 70-100mg OR Succinylcholine 100mg

Midazolam 3-5mg (every 20mins)
+ Fentanyl 0,15mg (every 20 mins)

Version 2:

S-Ketamin 35-100mg
+ Midazolam 7mg
+ Rocuronium 70-100mg OR Succinylcholine 100mg

Midazolam 3-5mg (every 20mins)
+ S-Ketamin 20mg (every 20 mins)

What I think: I think this is a great step forward to standardize the prehospital airway management in Germany. Ketamine was prominently managed, even while some Anesthesiologists out there still seem to think of it only a „last resort medication in trauma“. Also,the focus pre-, peri- and post-RSI communication within the team is very well done. Some medication combinations are not what I would use, but there are very good arguments in all the cases. Notably absent is the use apneic oxygenation. Maybe in the next version there will be a stronger emphasis on video laryngoscopy, checklists and even a part on prehospital procedural sedation.

But what do you think? Is this similar to what you use in the prehospital field (or the resus room) or do you have totally different regimes?

Link to the german version of the recommendations: AWMF.


Definitv ein „must-read Paper“ des Airway-updates von embasic ist jenes von Scott Weingart ( und Richard Levitan (

Hier ist die Zusammenfassung der Empfehlungen ihres Artikels „Preoxygenation and Prevention of Desaturation During Emergency Airway Management“. Ich kann nur jedem ans Herz legen, sich den ganzen Artikel durchzulesen um auch die Hintergründe der Empfehlungen zu verstehen!

  • Präoxygenation: Denk an die Sauerstoffbindungskurve: Präoxygenierung verlängert das Zeitintervall bis die Sauserstoffkapazitäten des Patienten aufgebraucht sind.
  • Verwende dazu eine Maske mit Reservoir mit der höchstmöglichen Sauerstoffflussrate
  • Patienten mit ausreichendem Atemantrieb sollten 3 Minuten lang oder für 8 tiefe Atemzüge präoxygeniert werden.
  • Positiver Druck: CPAP-Maske, NIV, oder ein PEEP-Ventil am Beatmungsbeutel sollten in Betracht gezogen werden bei Patienten die trotz hohem FiO2 nicht über eine Sättigung von 93-95% kommen.
  • Oberkörper hoch zur Präoxygenierung!
  • Apnoeoxygenierung kann das Zeitintervall bis zur Entsättigung verlängern – verwende dazu eine Sauerstoffbrille mit 15L O2/min
  • Hypoxämische Patienten brauchen aktive Beatmungshübe (niedriger Druck, niedriges Volumen, niedrige Frequenzen) während der Apnoezeit bis das Muskelrelaxans zu wirken beginnt. Patienten mit einer SpO2 über 95% brauchen keine Beatmungshübe, zwischen 95% und 91% ist es eine Nutzen/Risikoabwägung.
  • Lagerung: Um die Atemwege frei zu halten sollten Patienten so positioniert werden, dass Ohrloch und Jugulum eine gerade Linie (ear to sternal notch position) bilden, sobald keine Spontanatmung mehr vorhanden ist: Heimlich Manöver anwenden. Nasopharyngeale Atemwege können ebenfalls nötig sein.
  • Rocuronium bietet wahrscheinlich eine sicherere Apnoezeit (es wird vermutet, dass durch die Faszikulationen von Succinylcholin mehr Sauerstoff verbraucht wird).

Den Artikel gibs hier.

Preoxygenation and Prevention of Desaturation During Emergency Airway Management
Weingart, Scott D. et al.
Annals of Emergency Medicine , Volume 59 , Issue 3 , 165 – 175.e1



Checklisten aller Art werden in den letzten Jahren vermehrt in Notaufnahmen, Operationssälen und auch im präklinischen Bereich verwendet. Ihr Nutzen wurde in verschiedensten Bereichen beschrieben.
Auch „The Royal College of Anaesthetists and The Difficult Airway Society“ empfiehlt in ihrem Report zu schweren Komplikationen im Atemwegsmanagement die Verwendung einer Checkliste für die Intubation von kritisch kranken Patienten.
Speziell in Situationen hoher Intensität und niedriger Fehlertoleranz stellen sie einen gewissen Rückhalt dar und dienen somit der Patientensicherheit.
Für die präklinische Narkoseeinleitung wurde am Grazer Notfallwagen ebenfalls eine Checkliste erstellt. Ziel ist es Fehler schon vor Beginn einer Narkoseeinleitung zu erkennen und optimale Bedingungen herzustellen. Auch wenn es erscheinen mag, dass ein Durchlaufen einer Checkliste lange Zeit in Anspruch nimmt, ist dies in der Realität und bei einem gut eingespielten Team in ca. 30 Sekunden erledigt.

hier gehts zur Checkliste

Trauma Manual zum gratis Download!

ATACC (Anasthesia Trauma And Critical Care) bietet neben einem Trauma Kurs auch ihre Handbücher gratis zum Download (es lebe FOAM) an. Obwohl ich den Kurs selber nicht kenne, scheint das Manual gespickt mit interessanten Informationen und neuen Erkenntnissen (sowohl prä- als auch inhospital) zu sein. Auf alle Fälle einen Klick wert!

hier gehts zum Download


Du bist nicht allein! DocSteps Berlin 2014

Für alle, die über die DocSteps auf diese kleine, feine Seite gelangt sind – hier eine Zusammenfassung der wichtigsten Punkte und Links unseres Vortrags:

RUSH-Ultraschall-Protokoll auf EMcrit: LINK
Geniale US-Notfallseite – lifeinthefastlane: LINK

DGINA: Website / DGINA YED (  / DGINA Blog

DGINA-YED Famulaturprojekt (online ab 6.4.2014): LINK

DGINA Kongress Nürnberg 2014: LINK

StartED – Notfallmedizinkurs: LINK
FaktorMensch: LINK


Und hier auf gibt’s auch schon ein paar Inhalte – beispielsweise einen „Einsteigerguide für Notfallmediziner“ und mehr. Einfach durchstöbern…

Chest X-ray

Hier haben wir auf Youtube ein wunderbar geniales Tutorial gefunden mit dem fand blitzschnell lernt, ein Thorax-Röntgen Bild sicher und korrekt zu interpretieren – angefangen mit dem Basics bis hin zu den einzelne Differentialdiagnosen, die man berücksichtigen muss…


Viel Spaß beim Lernen wünscht euch das goldenhour-team