Tag Archives: Tips


The REAL Shocked Patient

I promised to put some summary notes on the site for those who attended my talk on ‘The REAL Shocked Patient’ for the Australian College of Ambulance Professionals on Tuesday 21st February 2012, so here they are:

Shocked patients are important – they comprise most of the ‘talk and die’ caseload that preoccupies pub conversations between emergency physicians

It’s easy to mistake these patients as less sick than, say, hypoxic ones, but oxygen delivery to the tissues doesn’t just depend on oxygen!

Here’s a dead wombat – someone in the audience knew a worrying amount about wombat anuses.

The 4 Hs and 4 Ts aren’t a very cognitively practical mnemonic for the causes of PEA arrest (which is an extreme form of hypotension)

I prefer the ‘3 plus 3’ rule, which breaks down the causes into three – volume, pump, and obstruction. Obstruction is further broken down into three causes, being tension pneumothorax, cardiac tamponade, and pulmonary embolism:

Let’s look at some cases of shock caused by volume deficit, pump falure, or one of the three causes of obstruction to the circulation:

 

Case 1: The hypotensive motorcyclist
His low back pain suggested pelvic fracture
Think of ‘blood on the floor and four more’ (chest, abdomen, pelvis/retroperitoneum, long bones) and consider non-bleeding causes such as neurogenic (spinal injury), tension pneumothorax, cardiac tamponade, and finally medical causes/iatrogenic (drug) causes.
Don’t underestimate the importance of pelvis and limb splinting as a haemorrhage control technique in blunt trauma
Ultrasound in flight made thoracic or abdominal bleeding very unlikely, and ruled out tamponade and pneumothorax

Although he was hypotensive, no fluids were given, as he was mentating normally and peripherally well perfused, with a radial pulse. If we gave fluid, we would titrate to the presence of a radial pulse (in blunt trauma) but we don’t want to ‘pop the clot’ by elevating the BP, or make him less able to form effective clots by diluting his blood with crystalloid.

Mortality in trauma sharply rises with systolic BP below 105-110, so recalibrate your definition of hypotension in terms of when you might be concerned, and which patients may benefit from triage to a trauma centre.

 

Case 2: The child crushed by a wall
Caution regarding lower limb infusions in patients with abdominal / pelvic injuries – the fluid may not get to the heart.

The classification of shock into four classes is crap. Never let the absence of a tachycardia reassure you.

Intraosseous is awesome, and EZ-IO has the best track record by far.

 

Case 3: The boy stabbed in the upper thigh
In penetrating limb trauma, prehospital options include pressure, elevation, tourniquet, and haemostatic dressings. Foley catheters have been used successfully in transition zones such as the neck or groin.

 

Case 4: Haematemesis
Should we apply the same principles of permissive hypotension to patients with ‘medical’ bleeding?
The Trendelenburg position doesn’t make a lot of sense – no need to head down the patient, although the act of elevating the legs may ‘autoinfuse’ a bolus of blood to the core circulation, and is recommended by some bodies as a first aid manoeuvre for hypotensive patients in the field prior to iv fluids.

 

Case 5: The overdose patient with a low blood pressure but otherwise fine.
When don’t I Worry about hypotension? When the patient is:

  • With it
  • Warm peripherally
  • Weeing
  • and (in hospital) Without a raised lactate


Case 6: Two cases of pump failure: STEMI and complete heart block
Adrenaline infusions can be simply made with a 1mg 1:10000 minijet diluted in a litre of saline and dripped through a peripheral line titrated to BP / HR / mentation / pulses.
In complete heart block (or other bradycardias) with hypotension, percussion pacing is an option of you don’t have access to transcutaneous or transvenous pacing. If you get capture, it’s as effective in terms of stroke volume as a pacing wire.

 

Case 7: Obstructive shock – tamponade cases
…with resolution of hypotension after drainage by emergency physicians who identified the tamponade on ultrasound, even though they didn’t suspect it clinically. It can be a surprise!

 

Case 8: Obstructive shock – tension pneumothorax
Patients are often agitated and won’t lie flat. They may complain of ‘tight’ breathing. Crackles and/or wheezes may be heard. The classic description of deviated trachea, absent breath sounds, and hyperresonance are the exception, not the rule. Be suspicious and always palpate for subcutaneous emphysema.
Don’t assume a needle decompression will work – there is debate about the best site but in some adults a standard needle won’t reach the pleural space. If you need to place more than one needle, go for it. As physicians, we do thoracostomies to ensure we’ve hit the spot.

 

Case 9: Obstructive shock – pulmonary embolism
A tough one prehospital, as the hypotensive ones need fibrinolysis. Fluid may help the hypotension but too much can overdistend the right ventricle which can then impair left ventricular filling, and worsen the patient’s circulatory state. Once again, ultrasound may be invaluable in highlighting PE as a possible cause for shock.

 

Case 10: Penetrating trauma to the ‘box’ – chest and upper abdomen.
If these patients arrest due to tamponade, early (< 10 minutes) clamshell thoracotomy can be life saving, which means it may need to be done pre-hospital by a HEMS physician to provide a chance of survival. Be on the look out for these and if in doubt activate a medical team (in New South Wales). Like with tension pneumothorax, these patients may be extremely agitated as a manifestation of their shock.

 

Case 11: Confused elderly male with pyrexia and smelly urine who appears ostensibly ‘normotensive’
…but how many 82 year olds do you know with a BP of 110/57? His acute confusion may be a manifestation of shock and he needs aggressive evaluation in hospital including a lactate measurement. Don’t be afraid to give this guy fluids in the field – you can make a big difference here.

Here are five of the myths I promised to expose:

So…shocked patients can talk and die. Don’t let that happen. Shocked patients can be normotensive, and hypotensive patients might not be shocked. Have a plan for how you might evaluate the 3+3 causes in your setting and what you can use from your medication and equipment list to manage volume, pump, and obstruction issues. You will save many lives if you become a serious shock detective.

Adjacent haemofiltration catheters can remove CVC drugs

An important consideration when siting your lines in your critical care patients who require renal replacement therapy…



Dual-lumen haemodiafiltration catheters enable continuous renal replacement therapy in the critically ill and are often co-located with central venous catheters used to infuse drugs. The extent to which infusions are immediately aspirated by an adjacent haemodiafiltration catheter remains unknown. A bench model was constructed to evaluate this effect. A central venous catheter and a haemodiafiltration catheter were inserted into a simulated central vein and flow generated using centrifugal pumps within the simulated vein and haemodiafiltration circuit. Ink was used as a visual tracer and creatinine solution as a quantifiable tracer. Tracers were completely aspirated by the haemodiafiltration catheter unless the infusion was at least 1 cm downstream to the arterial port. No tracer was aspirated from catheters infusing at least 2 cm downstream. Orientation of side ports did not affect tracer elimination. Co-location of central venous and haemodiafiltration catheters may lead to complete aspiration of infusions into the haemodiafilter with resultant drug under-dosing.


Adjacent central venous catheters can result in immediate aspiration of infused drugs during renal replacement therapy
Anaesthesia. 2012 Feb;67(2):115-121

Essential Retrieval Medicine Toolkit

Australian retrieval medicine guru and Flying Doctor Dr Minh Le Cong sent me a copy of the ‘Prehospital Anaesthesia and Airway management Syllabus 2012’ that he’d authored, a thorough and evidence-based approach to airway management for practioners involved in pre-hospital care and critical care transport.

In the surgical airway section, Minh describes the use of ultrasound as an adjunct to the identification of the cricothyroid membrane. It includes this image of Minh ultrasounding his own neck in his office.

I couldn’t help but be distracted by an object on his desk, which on closer inspection, appears to be a rubber chicken.

I emailed Minh to find out about that chicken. He replied:

..even I did not pick that my rubber chicken was visible in the shot!


A great tip from an ex SAS soldier…always carry a rubber chicken into high stress, high risk situations. You would be surprised how well it works in defusing high tension, arguments and standoffs as well as personally allowing you to take a moment and ground yourself when the shit is flying.


The chicken comes with me, along with my king vision, portable USS and Leatherman Multitool and head torch.I used all of those items recently on the same patient!


Minh Le Cong
Medical Education Officer
RFDS Queensland Section




What are the essential items you have with you on every shift? Is your list anything like Minh’s Retrieval Toolkit?

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]


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.

Intubation checklist

Perhaps you’ve read the blog post and heard the podcast about the excellent NAP4 airway audit…..now you can start putting the learning points into action with the intubation checklist, developed by the regional trainee-led collaborative ‘RTIC Severn’. Thanks to Dr Tim Bowles for the link:

I’ve used an RSI checklist for both in-and-out of hospital intubations for the last seven years. The beauty of this one is the potential for it to become a standard within and between hospitals, so wherever you work the team will be on the same page when preparing for intubation.

Further details are at http://saferintubation.com

Tube tip top tip

I’m not sure what this offers over purpose-built supraglottic airways, but effective ventilation may be achieved after failure of mask ventilation by siting a tracheal tube with its tip in the pharynx and the cuff inflated with 20 mls. The tube ‘is gently inserted 10—14cm, dependent on patient size, or until any resistance is felt, in caudal direction by letting the tip of the tube follow the palate and the posterior pharyngeal wall (in order to place the tip of the tube posterior to the epiglottis)’. As long as the tube tip or Murphy eye is not in the oesophagus, ventilation should be possible. The hand position maintains a jaw thrust while closing the mouth and occluding the nostrils.



BACKGROUND: Mask ventilation occasionally fails. Alternative readily available and simple methods to establish ventilation in these cases are needed.


METHODS: Retrospective description of cases in which a new technique, tube tip in pharynx (TTIP) ventilation, was employed for restoring ventilation in case of failed facemask ventilation during induction of anaesthesia. The technique involves a standard endotracheal tube and can be performed single-handed: A standard endotracheal tube was placed via the mouth with the tip in the pharynx and the cuff was inflated. By placing the fourth and fifth fingers below the ramus of the mandible, the third finger below the lower lip, the second finger above the upper lip and on one side of the nose and the first finger on the other side of the nose, an open airway is restored. Chin lift is inherent in the grip, thus contributing to opening of the airway.


RESULTS: In all four cases of failed mask ventilation the anaesthetist could establish an open airway and subsequent ventilation without the need for an assistant. There were no indications of gastric insufflation.


CONCLUSION: The TTIP technique established ventilation in all four patients after abandoned facemask ventilation. The technique only involves one person and an endotracheal tube and warrants to be included in the armamentarium of anaesthetists. Further prospective studies are needed to refine the technique and delimit its indications.




Tube tip in pharynx (TTIP) ventilation: simple establishment of ventilation in case of failed mask ventilation
Acta Anaesthesiol Scand. 2005 Feb;49(2):252-6

Two hands on the jaw for mask ventilation

Elective surgery patients were anaesthetised with propofol with or without fentanyl and had an oropharyngeal airway placed. They were ventilated with pressure control ventilation via facemask held with a single handed traditional ‘EC clamp’ grip and with a two-handed jaw thrust, and compared. The order in which these two techniques were trialled was randomised. All breaths were delivered with a peak pressure of 15 cm H2O, an inspiratory-to-expiratory ratio of 1:1, at a frequency of 15 breaths per minute. Ventilation was more effective with the two handed technique.

Using a self-inflating bag for resuscitation, this would translate to a two-person technique. Of note in methodology however was use of a ‘standard pillow’ and some emphasis on head extension. Perhaps ventilation would have been more effective with either technique if they had applied the golden rule of ear-to-sternal-notch positioning: a must for effective mask ventilation and successful laryngoscopy.

BACKGROUND: Mask ventilation is considered a “basic” skill for airway management. A one-handed “EC-clamp” technique is most often used after induction of anesthesia with a two-handed jaw-thrust technique reserved for difficult cases. Our aim was to directly compare both techniques with the primary outcome of air exchange in the lungs.

METHODS: Forty-two elective surgical patients were mask-ventilated after induction of anesthesia by using a one-handed “EC-clamp” technique and a two-handed jaw-thrust technique during pressure-control ventilation in randomized, crossover fashion. When unresponsive to a jaw thrust, expired tidal volumes were recorded from the expiratory limb of the anesthesia machine each for five consecutive breaths. Inadequate mask ventilation and dead-space ventilation were defined as an average tidal volume less than 4 ml/kg predicted body weight or less than 150 ml/breath, respectively. Differences in minute ventilation and tidal volume between techniques were assessed with the use of a mixed-effects model.

RESULTS: Patients were (mean ± SD) 56 ± 18 yr old with a body mass index of 30 ± 7.1 kg/m. Minute ventilation was 6.32 ± 3.24 l/min with one hand and 7.95 ± 2.70 l/min with two hands. The tidal volume was 6.80 ± 3.10 ml/kg predicted body weight with one hand and 8.60 ± 2.31 ml/kg predicted body weight with two hands. Improvement with two hands was independent of the order used. Inadequate or dead-space ventilation occurred more frequently during use of the one-handed compared with the two-handed technique (14 vs. 5%; P = 0.013).

CONCLUSION: A two-handed jaw-thrust mask technique improves upper airway patency as measured by greater tidal volumes during pressure-controlled ventilation than a one-handed “EC-clamp” technique in the unconscious apneic person.

A Two-handed Jaw-thrust Technique Is Superior to the One-handed “EC-clamp” Technique for Mask Ventilation in the Apneic Unconscious Person

Anesthesiology. 2010 Oct;113(4):873-9

Pull that tongue

A way of improving glottic visualisation when attempting fibreoptic intubation is for an assistant to perform a jaw thrust manoeuvre. This is nicely demonstrated in a video on the New England Journal website. However my retrieval medicine colleague and anaesthetist Dr Anthony Lewis pointed out the following situation and its solution:

What if they are a ‘difficult airway’ and you the jaw can’t move? Get your Magills forceps, grab the tongue and pull the tongue out. Very nice!

Balloon catheters for haemorrhage control

Something I keep up my sleeve (not literally) for managing some life-threatening vascular wounds prior to surgery is the use of a balloon catheter like a foley to tamponade haemorrhage. This paper looks at series of such attempts although they state: “Except for the base of the skull (naso/oropharynx), all catheters were de- ployed in the operating room.“, so not exactly emergency medicine / pre-hospital practice, but a useful reminder that this is an option when going immediately to the operating room isn’t:

BACKGROUND: : Balloon catheter tamponade is a valuable technique for arresting exsanguinating hemorrhage. Indications include (1) inaccessible major vascular injuries, (2) large cardiac injuries, and (3) deep solid organ parenchymal bleeding. Published literature is limited to small case series. The primary goal was to review a recent experience with balloon catheter use for emergency tamponade in a civilian trauma population.

METHODS: : All patients requiring emergency use of a balloon catheter to tamponade exsanguinating hemorrhage (1998-2009) were included. Patient demographics, injury characteristics, technique, and outcomes were analyzed.

RESULTS: : Of the 44 severely injured patients (82% presented with hemodynamic instability; mean base deficit = -20.4) who required balloon catheter tamponade, 23 of the balloons (52%) remained indwelling for more than 6 hours. Overall mortality depended on the site of injury/catheter placement and indwelling time (81% if <6 hours; 52% if ≥6 hours; p < 0.05). Physiologic exhaustion was responsible for 76% of deaths in patients with short-term balloons. Mortality among patients with prolonged balloon catheter placement was 11%, 50%, and 88% for liver, abdominal vascular, and facial/pharyngeal injuries, respectively. Mean indwelling times for iliac, liver, and carotid injuries were 31 hours, 53 hours, and 78 hours, respectively. Overall survival rates were 67% (liver), 67% (extremity vascular), 50% (abdominal vascular), 38% (cardiac), and 8% (face). Techniques included Foley, Fogarty, Blakemore, and/or Penrose drains with concurrent red rubber Robinson catheters. Initial tamponade of bleeding structures was successful in 93% of patients.

CONCLUSIONS: : Balloon catheter tamponade can be used in multiple anatomic regions and for variable patterns of injury to arrest ongoing hemorrhage. Placement for central hepatic gunshot wounds is particularly useful. This technique remains a valuable tool in a surgeon’s armamentarium.

A Decade’s Experience With Balloon Catheter Tamponade for the Emergency Control of Hemorrhage
J Trauma. 2011 Feb;70(2):330-3

Bum crack fluid pump

Military guys are great at coming up with practical solutions. Need to infuse fluid in the field but have no pressure bag or drip stand? Putting the bag under the patient’s body can squeeze fluid in, but the best place under the patient wasn’t known. A volunteer military study infusing saline through a 14G cannula compared six under-body locations: heels, buttock cleft, sacrum, interscapular region, cervical spine and occiput.

The buttock cleft was best.


Using body weight as a pre-hospital fluid infusion device: the relationship between under-body position and flow rate.
J R Army Med Corps. 2008 Mar;154(1):31-3
Full text article