Lateral chest thrusts for choking

An interesting animal study examined the techniques recommended in basic choking management algorithms for foreign body airway obstruction (chest and abdominal thrusts). In terms of the pressures generated, lateral chest thrusts were the most effective, although they are not recommended in current guidelines.

The technique described (on intubated pigs) was:

The animals were placed on the floor and on their side. The lower (dependent) side of the chest was braced by the ground and thrust was applied to the upper part of the upper side by two hands side by side with the higher one just below the axilla.

Interestingly – and I didn’t know this (although perhaps should have!) – the Australian Resuscitation Council (ARC) recommended lateral chest thrusts instead of abdominal thrusts for over 20 years.

While we should always exercise extreme caution in extrapolating animal studies to humans, this makes me want to consider lateral thrusts in the first aid (ie. no equipment) situation if other measures are failing.

Lateral versus anterior thoracic thrusts in the generation of airway pressure in anaesthetised pigs
Resuscitation. 2013 Apr;84(4):515-9
Abstract

London Calling – part 2

Notes from Days 2 & 3 of the London Trauma Conference

Day 2 of the LTC was really good. There were some cracking speakers who clearly had the ‘gift’ when it comes to entertaining the audience. No death by PowerPoint here (although it seems Keynote is now the presentation software of choice!). The theme of the day was prehospital care and major incidents.

The golden nuggets to take away include: (too many to list all of course)

• ‘Pull’ is the key to rapid extrication from cars if time critical from the Norweigan perspective. Dr Lars Wik of the Norweigen air ambulance presented their method of rapid extrication. Essentially they drag the car back on the road or away from what ever it has crashed into to control the environment and make space (360 style). They put a paramedic in the car whilst this is happening. They then make a cut in the A post near the roof, secure the rear of the car to a fire truck or fixed object with a chain and put another chain around the lower A post and steering wheel that is then winched tight. This has the effect of ‘reversing’ the crash and a few videos showed really fast access to the patient. The car seems to peel open. As they train specifically for it, there doesn’t seem to be any safety problems so far and its much quicker than their old method. I guess it doesnt matter really how you organise a rapid extrication method as long as it is trained for and everyone is on the same page.

• Dr Bob Winter presented his thoughts on hangings – to date no survivor of a non-judicial hanging has had a C-spine injury, so why do we collar them? Also there seems no point in cooling them. All imaging and concern for these patients should be based on the significant soft tissue injury that can be caused around the neck.

• Drownings – if the patient is totally submerged probably reasonable to search for 30mins in water that is >6 degrees or 90mins if <6 degrees. After that it becomes a body recovery (unless there is an air pocket or some exceptional circumstance). Patients that have drowned should have early ventilatory support if they show any signs of resp distress.

• Drs Julian Thompson and Mark Byers reassured us on a variety of safety issues at major incidents. It seems the risk to rescuers from secondary bombs at scene is low. Very few terrorist attacks world wide, ever, have had secondary devices so rescuers should be reassured (a bit). Greatest risk to the rescuer, like always, are the silly simple things that are a risk every day, like tripping over your own feet! With reference to chemical incidents, simple PPE seems to be sufficient for the vast majority of incidents, even fairly significant chemical ones, all this mucking about in full air tight suits is probably pointless and means patients cant be treated (at all). This led to the debate of how much risk should we, as rescue staff, accept? Clearly there are no absolute answers but minimising all risk to the rescuer is often at conflict with your ability to rescue. Where the balance should lie is a matter for organisations and individuals I guess.

• Sir Prof Keith Porter also gave us an update on the future of Prehospital emergency medicine as a recognised medical specialty. As those in the know, know, the specialty has been recognised by the GMC and the first draft of trainees are currently in post. More deaneries will be following suit soon to begin training but it is likely to take some time to build up large numbers of trained specialists. Importantly for those of us who already have completed our training there will be an option to sub specialise in PHEM but it will involve undertaking the FIMC exam. Great, more exams – see you there.

 

Day 3 – Major trauma
The focus of day 3 was that of damage control. Damage control surgery and damage control resucitation. We had indepth discussions about how to manage pelvic trauma and some of the finer points of trauma resuscitation.

Specific points raised were:

• Pelvic binders are great and can replace an ex fix if the abdomen needs opening to fix a spleen for example.

• You can catheterise patients with pelvic fractures (one gentle try).

• Most pelvic bleeds are venous which is why surgeons who can pack a pelvis is better than a radiologist who can mainly only treat arterial bleeds.

• Coagulopathy in trauma is not DIC and is probably caused by peripheral hypoperfusion.

• All the standard clotting tests that we use (INR etc) are useless and take too long to do. ROTEM or TEG is much better but still not perfect.

Also, as I am sure will please many – pressure isn’t flow so dont use pressors in trauma!

 

 

Chris Hill is an emergency and prehospital care physician based in the United Kingdom

Reassurance: difficult laryngoscopy in children remains rare

I was taught a useful principle by a paediatric anaesthetist 10 years ago which has proven true in my experience and has contributed to keeping me calm when intubating sick kids. Unlike adults, in whom difficulty in intubation can often be unexpected, the vast majority of normal looking children are easy to intubate, and the ones who are difficult usually have obvious indicators such as dysmorphism.

This appears to be supported by recent evidence: in a large retrospective series of 11.219 anaesthesia patients, the overall incidence of difficult laryngoscopy [Cormack and Lehane (CML) grade III and IV] was only 1.35%, although was much higher in infants less than one year compared with older children. This low percentage is in the same ball park as two other paediatric studies. Besides younger age, their database suggested underweight, ASA III and IV physical status and, if obtainable, Mallampati III and IV findings as predictors for difficult laryngoscopy. The authors point out:

“…the oromaxillofacial surgery department with a high proportion of cleft palate interventions and pediatric cardiac surgery contributed substantially to the total number of difficult laryngoscopies. In patients undergoing pediatric cardiac surgery, a possible explanation for the higher incidence of CML III/IV findings might be that some congenital heart defects are associated with chromosomal anomalies like microdeletion 22q11.2 syndrome. This syndrome is also associated with extracardiac anomalies like cranio-facial dysmorphism“

Take home message: As a very rough rule of thumb to illustrate the difference between the ease/difficulty of laryngoscopy between adults and kids, I think it’s fair to say grade III or IV views occur in about 10% of adults but only about 1% of children.

Incidence and predictors of difficult laryngoscopy in 11.219 pediatric anesthesia procedures
Paediatr Anaesth. 2012 Aug;22(8):729-36
Click for abstract

Externally rotate leg for femoral vein access

Want to access the femoral vein? Externally rotate the leg at the hip and things might be a bit easier. This study was done in adult patients, with the knee straight and no abduction applied. External rotation is also helpful in kids, with abduction up to sixty degrees.

Objective: To determine if external rotation of the leg increases the size and accessibility of the femoral vein compared with a neutral position.

Methods: One hundred patients presenting to a tertiary teaching hospital were prospectively recruited. The right common femoral vein of each subject was scanned with a linear probe (5–10 MHz) inferior to the inguinal ligament, with the leg in a neutral position and then in the externally rotated position. The transverse diameter of the femoral vein, the accessible diameter of the vein (lying medial to the femoral artery) and the depth of the vein were measured.

Results: The mean diameter of the femoral vein in the externally rotated leg was greater than with the leg in the neutral position (15.4 mm vs 13.8 mm); the mean difference was 1.6 mm (95% CI 1.3–1.9). The mean accessible diameter of the femoral vein was larger with the leg externally rotated (13.8 mm vs 11.7 mm, mean difference 2.1 mm, 95% CI 1.8–2.5). The depth from the skin to the femoral vein was less with the leg in external rotation (20.9 mm vs 22.6 mm, mean difference 1.7 mm, 95% CI 1.2–2.2). The mean diameter and depth were greater in patients with overweight or obese body mass index (BMI) measurements in both leg positions. The increase in femoral vein diameter and accessibility with external rotation was observed in all BMI groups.

Conclusion: The total and accessible femoral vein diameter is increased and the surface depth of the vein is decreased by placing the leg in external rotation compared with the neutral position.

Simple external rotation of the leg increases the size and accessibility of the femoral vein
Emerg Med Australas. 2012 Aug;24(4):408-13

Finally I understand ultrasound physics

Ever waste time trying to shake some ultrasound gel out the bottle, like a resistant blob of ketchup?
Sydney emergency medicine registrar Dr Steve Skinner demonstrates how to solve this. With physics.

This really does work, and has saved me a lot of time already. I now do a somewhat less ballistic version than the one demonstrated, so that patients don’t think I’m mad.

This video is for entertainment purposes only. We accept no responsibility for injuries sustained as a result of unaccustomed shoulder activity or inadvertently launched plastic projectiles.

Still no oil painting

During a Krav Maga self defence drill a middle aged martial arts enthusiast cleverly blocked a full contact punch with his nose. Following a suggestion to pause training to control the bleeding, he noticed some lateral nasal displacement which was easily manually reduced with an audible click. He was able to resume training with a piece of toilet paper stuffed up the bleeding nostril, and no ill effects were noticed on subsequent training nights that week.

The day after injury he demonstrated a characteristic bruising pattern:

As he was working an aeromedical retrieval shift, he was able to use the Retrieval Service Sonosite M-Turbo ultrasound machine to identify the cortical disruption from his nasal bone fracture.

Ultrasound compares favourably with both plain radiography(1) and computed tomography(2) in the diagnosis of nasal bone fractures.

Personal access to sonography and full board certification in emergency medicine help to decrease health care costs and emergency department load when individuals sustain fractures that do not require operative management(3).

1. Comparison of ultrasonography and conventional radiography in the diagnosis of nasal fractures.
Arch Otolaryngol Head Neck Surg. 2005 May;131(5):434-9

2. Comparison of high-resolution ultrasonography and computed tomography in the diagnosis of nasal fractures.
J Ultrasound Med. 2009 Jun;28(6):717-23

3. Only when I laugh
When the same bloke broke his rib

Facilitated pericardial drainage

Drs Wyatt and Haugh describe a modified resuscitative thoracotomy technique which provided surgically facilitated pericardial drainage. A patient with a ruptured pseudoaneurysm of the right ventricular outflow tract presented in shock and arrested in the ED. She had had a prior history of idiopathic ventricular tachycardia and had undergone cardiac ablation of the posteroseptal wall of the right ventricular outflow tract. Sonographically identified tamponade was treated with pericardiocentesis which failed due to clotted blood, so a left lateral thoracotomy was performed by the emergency physician. Rather than fully expose the heart for repair in the ED, they elected to just make a 2cm incision in the pericardium which allowed drainage of blood and restoration of circulation. This was combined with blood product transfusion to buy time for the arrival of a cardiothoracic surgeon and transfer to the operating room.

Useful learning points from this paper are:

• Ablation procedures are becoming more common
• Serious complications such as atrioesophageal fistula, pseudoaneurysm, pericardial effusion, and cardiac tamponade occur approximately 3% of the time
• When tamponade is suspected or confirmed ask patient about recent cardiac procedures such as catheterisations, surgery, and ablation procedures
• Radiofrequency ablation procedures are often performed on the right side of the heart in areas that may be relatively inaccessible from a left-sided lateral thoracotomy approach.

Modified Emergency Department Thoracotomy for Postablation Cardiac Tamponade
Ann Emerg Med. 2012 Apr;59(4):265-7
Click for abstract

Superglue for CVCs

In resuscitation situations, the securing of vascular catheters is an important but sometimes cumbersome process, particular when sutures are required for central lines or arterial lines.

Medical grade ‘superglue’ (cyanoacrylate) can be used and this has been described in the anaesthetic literature before(1). Now, further in vitro work shows the glue does not weaken the intravenous catheter and is not associated with bacterial colonisation(2).

I think this is perfect for resuscitation lines. Just last night I used this technique to secure a femoral arterial line during a cardiac arrest resuscitation. It was great not to have to faff around with sharp suture needles during CPR and the line felt very secure after just a few seconds.

1. Tissue adhesive as an alternative to sutures for securing central venous catheters
Anaesthesia. 2007 Sep;62(9):969-70

2. Cyanoacrylate tissue adhesives – effective securement technique for intravascular catheters: in vitro testing of safety and feasibility
Anaesth Intensive Care. 2012 May;40(3):460-6
Click for abstract

From BURP to BILP: backwards internal laryngeal pressure

A burns patient whose tracheal tube was accidentally dislodged and ended up placed in the oesophagus on day 2 of his ICU stay continued to spontaneously ventilate and maintain saturations on a midazolam infusion. The oesophageal tube was left in during laryngoscopy (after propofol but no muscle relaxant due to anticipated difficult airway) which revealed a cormack-lehane grade 3 view. The operator’s hand which was holding a bougie rested on the oesophageal tube, which displaced it backwards. This resulted in backwards displacement of the larynx and improved the glottic view to 2b, facilitating intubation.

The discovery of this ‘backwards internal laryngeal pressure’ manoeuvre led the authors to make the recommendation that during difficult intubation an inadvertently placed oesophageal tube should be left in place to allow a BILP manouevre, but removed if it impedes the passage of the tracheal tube.

I love anything that might improve success rates of critical procedures and this one could conceivably come in handy. I can just see Minh Le Cong inventing a transoesophageal posterior laryngal retractor for under 50 bucks…

The use of “Internal Laryngeal Pressure” to improve the laryngeal view following inadvertent oesophageal intubation in a patient with difficult airway
Anaesth Intensive Care. 2012 Jul;40(4):736-7

Laryngospasm after Ketamine

A case is reported in Prehospital Emergency Care¹ in which an agitated patient (due to mania and alcohol intoxication) received 5 mg/kg (500 mg) of ketamine intramuscularly by an EMS crew which dissociated him within a few minutes. He subsequently developed episodes of laryngospasm in the emergency department which were unrelieved by head tilt, chin lift and simple airway adjuncts but responded to bag-mask ventilation (BMV). The patient was intubated because the laryngospasm recurred, although it had again responded to BMV.

The authors make the point that because of the response of laryngospasm to simple manoeuvres, and because in the prehospital environment a patient will not be left without an EMS provider present, ‘restricting ketamine to EMS units capable of rapid-sequence intubation therefore seems unnecessary.‘

This is one for EMS directors to consider seriously. Personally, I think practicing prehospital care without access to ketamine is like having a hand tied behind my back. Ketamine opens up a world of possibilities in controlling combative patients, optimising scene safety, providing sedation for painful procedures including extrication, and enabling severe pain to be controlled definitively.

I’ve been using ketamine regularly for prehospital analgesia and emergency department procedural sedation in both adults and kids for more than a decade. I’ve seen significant laryngospasm 5 times (twice in kids). On one of those occasions, a 3 year old child desaturated to around 50% twice during two episodes of laryngospasm. We weren’t slow to pick it up – that was just her showing us how quickly kids can desaturate which continued while we went through a stepwise approach until BMV resolved it. It was however an eye opener for the registrar (senior resident) assisting me, who became extremely respectful of ketamine after that. Our ED sedation policy (that I wrote) required that suxamethonium was ready and available and that an appropriate dose had been calculated before anyone got ketamine. Paralysis may extremely rarely be required, but when it’s needed you need to be ready.

Laryngospasm is rare but most regular prescribers of ketamine will have seen it; the literature says it occurs in about 1-2% of sedations, although anecdotally I think it’s a bit less frequent. Importantly for those weighing the risks of allowing non-RSI competent prescribers, the requirement for intubation is exceptionally rare (2 of 11,589 reported cases in one review). Anyone interested should read this excellent review of ketamine-related adverse effects provided by Chris Nickson at Life in The Fast Lane. Chris reminds us of the Larson manouevre, which is digital pressure in the notch behind and below the ear, described by Larson² as follows:

The technique involves placing the middle finger of each hand in what I term the laryngospasm notch. This notch is behind the lobule of the pinna of each ear. It is bounded anteriorly by the ascending ramus of the mandible adjacent to the condyle, posteriorly by the mastoid process of the temporal bone, and cephalad by the base of the skull. The therapist presses very firmly inward toward the base of the skull with both fingers, while at the same time lifting the mandible at a right angle to the plane of the body (i.e., forward displacement of the mandible or “jaw thrust”). Properly performed, it will convert laryngospasm within one or two breaths to laryngeal stridor and in another few breaths to unobstructed respirations.

I use this point most often to provide painful stimuli when assessing GCS in a patient, particular those I think may be feigning unconsciousness (I’ve done this for a number of years since learning how painful it can be when I was shown it by a jujitsu instructor). Dr Larson says he was taught the technique by Dr Guadagni, so perhaps we should be calling it the ‘Guadagni manouevre’. The lack of published evidence has led to some appropriate skepticism³, but as it can be combined with a jaw thrust it needn’t delay more aggressive interventions should they become necessary, it may work, and it’s likely to be harmless.

I presented the following suggested algorithm for management of laryngospasm during ketamine procedural sedation at a regional emergency medicine ‘Fellows Forum’ meeting in November 2007 in the UK. Since many paediatric procedural sedations were done using intramuscular (im) ketamine, it gives guidance based on whether or not vascular access has been obtained:

Some things I considered were:

• Neuromuscular blockade (NMB) isn’t always necessary – laryngospasm may be managed with other sedatives such as propofol. However, titrating further sedatives in a desaturating child in my view is inferior to definitive airway management and laryngeal relaxation with suxamethonium and a tube.
• Laryngospasm may be managed with much smaller doses of suxamethonium than are required for intubation – as little as 0.1 mg/kg may be effective. However, I think once we go down the NMB route we’re committed to intubation and therefore we should use a dose guaranteed to be effective in achieving intubating conditions.
• In the child without vascular access, I considered intraosseous and intralingual sux. However, intramuscular suxamethonium is likely to have a relaxant effect on the laryngeal muscles within 30-45 seconds, which has to be compared with time taken to insert and confirm intraosseous needle placement. I do not think the traditionally recommended intralingual injection has any role to play in modern airway management.
• At the time I wrote this most paediatric resuscitation bays in my area in the United Kingdom had breathing circuits capable of delivering PEEP – usually the Ayr’s T-Piece (specifically the Mapleson F system), which is why PEEP was included early in in the algorithm prior to BMV.

ABSTRACT An advanced life support emergency medical services (EMS) unit was dispatched with law enforcement to a report of a male patient with a possible overdose and psychiatric emergency. Police restrained the patient and cleared EMS into the scene. The patient was identified as having excited delirium, and ketamine was administered intramuscularly. Sedation was achieved and the patient was transported to the closest hospital. While in the emergency department, the patient developed laryngospasm and hypoxia. The airway obstruction was overcome with bag–valve–mask ventilation. Several minutes later, a second episode of laryngospasm occurred, which again responded to positive-pressure ventilation. At this point the airway was secured with an endotracheal tube. The patient was uneventfully extubated several hours later. This is the first report of laryngospam and hypoxia associated with prehospital administration of intramuscular ketamine to a patient with excited delirium.

1. Laryngospasm and Hypoxia After Intramuscular Administration of Ketamine to a Patient in Excited Delirium
Prehosp Emerg Care. 2012 Jul;16(3):412-4

2. Laryngospasm-The best treatment
Anesthesiology 1998; 89:1293-4

3. Management of Laryngospasm
http://www.respond2articles.com/ANA/forums/thread/1096.aspx

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