The crashing intubated patient: DOTTS

R main stem intubation

Whenever a patient you have just intubated deteriorates, or a patient on a ventilator deteriorates quickly:

DOTTS

Disconnect and let them exhale:

This gets the ventilator out of the equation and simplifies things / reduces our cognitive load: we understand BVMs (bag-valve-mask), ventilators and circuits confuse and scare us.  It also stops ventilation for a few seconds and lets the patient exhale which will help with over inflation / breath stacking.  This is especially important in patients with asthma (see Pop goes the wheezer)

O2 via BVM, slow:

Ventilate the patient slowly with a bag-valve-mask.  Look at the chest movements, listen to the breath sounds.

Is only one side of the chest moving?  Is it a bronchial intubation (check tube depth, see below), a mucus plug (suction the tube, see below) or a pneumothorax (usually unlikely, we’ll check for this later, see below, but if it’s a trauma patient ultrasound and/or perform a finger thoracostomy now)?

Squeezing the bag lets us get a feel for what is going on: is the patient easy or hard to ventilate.  If the bag collapses easily but the chest doesn’t move the tube probably isn’t in the trachea or is disconnected from the bag.  If it is hard to squeeze the bag: it might be a problem with the tube or the patient.  In the above X-Ray the patient has a R main bronchus intubation with R lung hyperinflation and L lung collapse (which happens amazingly rapidly).

Tubes:

Is it in the ETT in right place, is it blocked, is there a big leak (tube too small or has the cuff deflated)?  Check the capnography trace:  Is there a good wave form?  Is the tube at the right depth (around 22cm at the teeth for an adult or ~ 3 times tube diameter (actually 30 times), or black mark on ETT just through the cords in kids)?

Suction the tube.  If the suction catheter goes right down, the tube is patent.   You may suck out a big mucus plug or piece of broccoli.

Tubes is also for a nasogastric or orogastric tube.  If you haven’t got one in get someone to put one in while you continue to trouble shoot, otherwise make sure that is working (aspirate stomach contents, or insufflate air and listen to it gurgle in the stomach.

In the above X-Ray the ETT is down the R main stem bronchus (it was at 19cm at the teeth in a 3 year old) and the NG tube is curled up in the upper airway and has not decompressed the stomach.  Kids especially can be difficult to ventilate, be hypoxic or hypotensive due to gastric distension increasing intrathoracic pressure

Tweak the vent:

Do you need to reduce the tidal volume or respiratory rate if the patient has stiff lungs?  We usually start with a tidal volume of 6ml/kg ideal body weight.

If the patient is ventilating OK but is still hypoxic you probably need to increase the PEEP.

Sonogram:

Ultrasound to look for pneumothorax.  This is last because it is relatively rare.

Get a chest X-Ray as well, but hopefully you will have fixed the problem using the above mnemonic before the radiographer arrives.

 

If the above hasn’t worked (it will sort the problem 99% of the time) get senior help! (if you haven’t already)

Next steps will depend on whether it appears to be a ventilation problem (hypoxia, difficult to ventilate) or a circulatory problem (easy to ventilate but hypotensive).  eg see http://lifeinthefastlane.com/pulmonary-puzzle-013/

 

The above patient apparently tolerated the misplaced tubes very well and the only clue was an end tidal CO2 in the hundreds.  With repositioning of tubes the patient quickly improved.

Audio:

 

 

Reference:

http://emcrit.org/wp-content/uploads/2013/08/The-crashing-ventilated-patient_EMCrit-Conference.pdf

Music (on podcast)

Nga Hau e Wha by Hui-a  https://itunes.apple.com/nz/album/got-to-live-ep/id318363878 www.jeromekavanagh.com

 

Diving sats? Check your oxygen supply

 

 

A cautionary tale from the not so distant past:

To cut a long and messy story short – a 6 month old child needed to be intubated for deteriorating bronchiolitis with pneumonia.

The infant was preoxygenated with a paediatric Bag-Valve-Mask (BVM) and the sats rose to 97%.

Then the sats dropped to 30% with good air entry.  Various basic airway manoeuvres were tried with no effect. There were good chest movements

One of the anaesthetists said “We need to secure the airway” and pushed the anaesthetic drugs.

About this time it was noticed that the BVM reservoir was empty and that the oxygen supply tubing was disconnected from the BVM. The oxygen was reconnected and the sats improved very quickly.

Lessons learned:

  • If sats dive consider oxygen supply failure as a cause.  Check from the wall or tank – is the rotameter ball floating, check the tubing, check the patient interface.  You may need a different oxygen source.
  • Rapidly falling sats with good air entry is unlikely to be due to an airway problem.
  • Use something that can provide PEEP to preoxygenate a respiratory patient eg a Neopuff. Most paeds BVMs don’t have a PEEP valve.  This would may have provided better oxygenation / denitrogenation and may have slowed the precipitous fall in O2 saturation
  • Use nasal cannula oxygenation as well as the BVM or non rebreather mask to preoxygenate during RSI – it will provide apnoeic oxygenation during RSI and be a back up oxygen supply if the BVM supply fails.  This also may have slowed the precipitous fall in sats.

 

 

 

 

Image from: http://www.iamnotthebabysitter.com/breastfeeding-through-infant-botulism/

Music:  Call me when you are sober.  Evanescence

Rapid Sequence Intubation

Audio:

 

Rapid sequence intubation (RSI) is the rapid anaesthetising and paralysing of a patient to facilitate tracheal intubation. RSI is the cornerstone of emergency airway management. There are many variations and nuances.  This post will only cover simple, standard RSI.

RSI is one of the most complex and dangerous procedures in emergency medicine.  Passing the tube through the cords, which we often get very focused on, is a very small part of the process.

In Australasia most ED RSIs are performed/supervised/lead by ED advanced trainees or emergency physicians.

RSI is not a technique for unsupervised junior doctors.   This post is to provide an introduction to RSI so you have an idea of what is going on, you can assist during an RSI, and to start building your knowledge of this technique.

Don’t worry that you don’t know how to RSI a patient yet.  There is almost no situation in which the patient needs an RSI before an expert team can be assembled.  In most situations you are better of using your basic airway skills until your seniors arrive.

Depending on your staffing and after-hours support you may need to get anaesthetics in for after-hours tubes. If it looks like a difficult tube, call for help. This is no time to be proud. If you have an obese hypoxic patient with no neck and a large beard, expect some difficulty. Similarly, a 5 year old with epiglottitis deserves a look in theatre with anaesthetics, not an ED intubation. There is always help, but you must ask for it if you need it!

Key points of RSI



  • Paralysing the patient to relax airway muscles, make it easier to see the vocal cords, and keep the cords open so we can pass the tube.
  • Anaesthetising the patient because being paralysed and having a plastic tube stuck in your trachea is rather unpleasant and cause a marked sympathetic surge (tachycardia and hypertension) which may be detrimental for some patients.
  • Pre-oxygenation to replace the 70% of nitrogen in the patients lungs with oxygen to increase the time the patient can tolerate the apnoea from the paralysis.
  • No ventilation during the apnoea to reduce the chance of insufflating the stomach which may cause vomiting
  • Check lists are becoming widely accepted way to reduce the risk of error.  A check list can be an aide memoir and a written record.

Here is one checklist

 

RSI checklist

Drugs

RSI pharmacology could be a talk on it’s own.

We are moving to a Cliff Reid style super simple, minimal cognitive load, ketamine and rocuronium only RSI.  Commonly known as Roketamine.

Rocketamine

In this post I’ll only talk about ketamine, rocuronium, fentanyl and pressors to keep things simple.  Different consultants may use other drugs.

You could argue about the pros and cons of this approach.  In Cliff Reid’s prehospital service they have dramatically decreased their times to RSI and total scene times.

All drugs are give as a fast IV or IO push, not slowly titrated as is done for elective anaesthesia.

For paeds doses uses an App e.g. Pedistat http://www.imedicalapps.com/2012/02/pedi-stat-quick-drug-equipment-reference-pediatric-emergency-critical-care/

We have a couple of boxes of all the RSI drugs stored in the drug room fridge to reduce the time required to find and sign-out the drugs.

Anaesthetics:



Ketamine:

Many in critical care are advocating ketamine as the default anaesthetic for RSI.  Ketamine ends to raise HR and BP.  Probably best agent in haemodynamically unstable patients.  Relatively contraindicated in patients who might be harmed from a BP increase e.g. SAH.  Dose 1-2mg/kg.  0.25-0.5mg/kg dose if patient shocked (Weingart. Essentials 2013). Ketamine does have some bronchodilatory properties, so is a nice agent for asthma and COPD.

Paralytics / Muscle Relaxants:



Rocuronium:

Fast acting (45 sec), long acting (~ 45 minutes). The only real contraindication is allergy to rocuronium.  Dose: 1.2 – 1.6 mg/kg. Use the higher dose if shocked to ensure enough drug gets to the receptors. (Weingart Essentials 2013) Roc rocks.

Pressor:

Push dose pressor eg adrenaline 10mcg, phenylephrine 100µg.  Have drawn up, just in case.  See http://emcrit.org/podcasts/bolus-dose-pressors/

Post intubation sedation and analgesia: 

Fentanyl:

Fentanyl (or other opioid) be used for analgesia prior to RSI and for analgesia post RSI.  Having a plastic tube stuck down your trachea is very painful and distressing.  Patients need good analgesia e.g. Fentanyl 1µg/kg bolus then 1µg/kg/hour titrated to effect.

Benzodiazepines

Benzos are going out of fashion for post intubation sedation as they are associated with increased delerium and longer ICU stays.  See http://emcrit.org/podcasts/post-intubation-sedation-2014/



Propofol:

Used for a haemodymically stable patient who you expect to wait up the next day or earlier   eg 0.1 mg/kg/hour titrated to effect.

Ketamine:

Can be used for sedation and analgesia for the haemodynamically unstable patient. eg 0.25-0.5mg/kg bolus if not used for RSI then 1mg/kg/hour

Process



People:  


RSI is a team sport.  5 people is a great number.  Minimum doctor skill level is an advanced trainee/senior registrar in emergency medicine.  
Assign roles (but flexibility required) 
e.g. 
team leader, 
intubator, intubator’s assistant (assess airway, prepare patient and equipment)
, scribe, 
drug preparers.

Give a heads up to X-Ray, Bed Manager, ICU so they can get a bed ready, CT if needed.

Patient assessment: AMPLE Hx, Anaesthetic Hx, Airway assessment: mouth opening, jaw mobility, view of oropharynx (Mallampati Score (0-4)), neck mobility (unless c-spine being immobilised), assess thyromental distance. Vital signs.  Any other patient assessment required.

Position:

Ramp the patient: put pillows or blankets under the patients thorax, head and neck as required to get tragus higher than sternum.  If the patients c-spine needs to be protected weigh up the pros and cons of positioning vs spinal protection.  NB neutral position for an elderly, kyphotic patient will require padding under the head to keep the neck flexed.  Due to large head of neonates and pads may need padding/board under thorax of child to prevent flexion of the neck.

Prepare equipment:

Suction, laryngoscopes, bougie, ETT with introducer, lubed  and half size smaller ETT, monitoring x 4: audible oximetry (“the beeps”), BP set to go every 2.5 minutes, cardiac monitoring, and wave form capnography.

Plan B and C: eg Intubating LMA, scalpel (cricothyroidotomy).

Paediatric equipment box with all airway equipment for the weight of child. Approximate size of endotracheal tube is age/4 +4

Prepare Drugs:  Ensure all your drugs are drawn up and labeled.

Preoxygenate:  Give high flow oxygen (15L/minute) via nasal prongs so that oxygen is being administered during laryngoscopy.  See No Desat   Also give O2 via non-rebreather mask or via bag-valve-mask (BVM) for 3 minutes.  This tends to vary with institution/country.  I prefer to use a BVM with the capnography attached so that I know the BVM and capnography are working.

Put to sleep and paralyse:  



A fast push of the anaesthetic drug(s) and paralytic each followed by a large flush. Note the time.

Pause: 

Keep the oxygen mask on the patient’s face.  Don’t bag the patient (we may back for a patient with dodgy lungs, but for a bog standard RSI, no bagging).  Wait about 30 seconds then start looking in the patient’s mouth.  Intubator readies laryngoscope.  Assistant ready to pass suction or ETT.  

Protection:

Some clinicians use cricoid pressure, to attempt to reduce the chance of aspiration. Cricoid pressure is controversial and practice varies greatly.  I don’t use it.

If you can’t see cords during intubation, try using your right hand to manipulate the larynx (similar to performing cricoid pressure) and push cords into view. You can then ask your assistant to provide that pressure while you pass the tube with your right hand.

Pass the tube:

Remove any false teeth.  Always hold your laryngoscope in your left hand.  Look in mouth.  Suction if necessary.  Epiglotoscopy then laryngoscopy.   Pass the tube through the cords to eg 22-24 cm at the teeth/gums for an adult male.  You can use the equation 3 x ETT size for paediatrics (place a 7-0 tube at 21cm). Inflate the ETT cuff till balloon firmish, but not hard.

If there a problems try manipulating the larynx or use a bougie.  If still problems move to plan B eg LMA.

Proof: 



Put the BVM and capnograph onto the ETT.  Bag-valve ventilate.  Look for fogging of the ETT, check chest movements, listen for breath sounds bilaterally, check capnography. The best proof is visualising the ETT going through the cords (this is much easier with a video laryngoscope. CXR (put the NG tube in first). If your sats are going down and there’s no chest rise, pull the tube and bag your patient back up. You can always take a second look when the oxygen saturation rises again.

Post intubation management:



Analgesic eg fentanyl 1µg/kg then 1 µg/kg/hr

.  See above.

Check and document:

A: Check level of ETT at the teeth gums.  Suction ETT.  CXR to check tube position (place an NG tube first (usually required for an intubated patient) so you can check NG tube and ETT placement with the X-Ray.

B: Place patient on ventilator eg SIMV, TV 6ml/kg ideal body weight.  RR 12.  Air-mix if possible. Head up 30˚ (except if you are concerned re a spinal injury) to reduce the risk of ventilator associated pneumonia (VAP), improve ventilation and ICP.

C: Check HR and BP.  ECG if indicated.  Maintenance fluids.  Other fluids if required.  Labs.  Arterial line and ABG if time/indicated.

D: Check pupils and analgesia. Any signs that the patient is under analgesed? eg tearing, tachycardia, hypertension, movement.

E: Thermoregulation as required.

G: Check the blood sugar if you haven’t already.  Urinary catheter

Referral: Make sure the patient is referred to an inpatient team, anaesthetist or intensivist and ICU, bed manager.

Other: Tertiary survey by receiving team, antibiotics, tetanus booster, further imaging

Documentation.

 

 

Written and presented by Dr Chris Cresswell, Emergency Physician

Edited by Dr Erik Adler, Emergency Physician

 

 

Music (on podcast): Crucify Your Mind.  Rodriguez.

Image from http://airway.jems.com/tag/prehospital-endotracheal-intubation/

 

Accidental Hypothermia

From Dr Doug Brown, lead author from the NEJM 2012 article on accidental hypothermia (Free full text article here: N Engl J Med 2012;367:1930-8). (Dr Brown was interviewed on EM:RAP Jan 2013)

This is the key flow chart from this article:

Hypothermia

His website includes the original article and an audio summary and a video summary for prehospital crews.  Shared with permission.

The audio summary is also available on the EM Tutorials podcast here

 

Frozen car image from http://thecelestialconvergence.blogspot.co.nz/2011_09_12_archive.html

Music (at the end of the podcast): https://itunes.apple.com/us/album/glee-music-christmas-album/id398792552