June 2019 podcast

Does everyone need an angio post OOHCA?

Paper

– Coronary Angiography after Cardiac Arrest without ST-Segment Elevation

Author

– Lemkes, NEJM 2019

Background

– Coronary artery disease is the most common cause of OOHCA. When there’s a clear STEMI post ROSC then the chances are very high you’ll find a coronary occlusion at angio. However we know the ECG isn’t particularly sensitive and that there are lots of post ROSC patients with coronary occlusions with non specific ECGs
– Prior observational data has suggested that all post ROSC patients should have an angio given the high prevalence disease and that this might be associated with better outcomes

Methods

– included only OOHCA, shockable rhythms and unconscious following ROSC
– multi centre RCT in the Netherlands
– excluded if STEMI on ECG or “obvious non coronary cause” which isn’t defined and could be open to all kinds of fudging
– randomised to angio within 2 hours or “delayed” to when there was neurological recovery
– survival at 90 days as primary outcome and a lot of this was by phone
– powered for a 12% absolute reduction in mortality (which seems optimisitc)

Results

– 550 patients
– lots of coronary disease found (65%) in the both groups but quite a low number of “unstable” (>70% stenosis) lesions at around 15% in both groups.
– ultimately just under a third got PCI in the immediate group and a quarter in the delayed group
– a third of patients in the delayed group never got an angio, presumably because they never neurologically recovered.
– delayed angios were done at day 4-5
– survival at 90 days was roughly 65% in both groups

Thoughts

– in this surprisingly well group of OOHCA patients it didn’t seem to matter when you did their angio if their ECG didn’t show a STEMI

– However they powered this trial looking for a massive difference in outcomes in a much sicker population than they actually recruited so i don’t think this trial is in any way definitive

– There are probably still lots of Non STEMI cardiac arrest patients who might benefit from an early angio. Selecting these might include improving our ECG reading, or PoCUS findings or incorporating more risk factors into that decision rather than simply using the blunt tool of STEMI/No STEMI

Further Reading

1. ResusRoom
2. Rebel EM 
3. EMCRIT

Coronary Angiography after Cardiac Arrest without ST-Segment Elevation

Authors:

Andy Neill
Peter Johns

Dr Johns is Assistant Professor, Department of Emergency Medicine, University of Ottawa and a vertigo enthusiast. He is best known for his excellent educational videos on youtube on vertigo.

The three main diagnoses we’re looking for in the ED are
1) Stroke – serious and somewhat common
2) BPPV – very common, not serious but treatable with the Epley usually
3) Vestibular neuritis – commonly mistaken for stroke or BPPV

The first step in Dr Johns approach is to screen for stroke with history and examination.

All vertigo is worse with movement but continuous vertigo even at rest should make you consider stroke and vestibular neuritis. A patient who cannot walk should make you worried for stroke. people may be unsteady with BPPV or neuritis but should still be able to walk. Severe headache and neck pain may indicate stroke or dissection and is also a red flag. The commonly described “deadly Ds” can also be enquired for
– Dysarthria
– Dystaxia
– Diplopia
– Dysphagia

If you have a history consistent with BPPV (short intermittent intense episodes and a normal neuro exam) then you can use the dix-hallpike as the gold standard confirmatory test.

If you have someone with continuous symptoms then don’t do a dix hallpike.

There are lots of great videos below that will help you understand the manoeveurs

Videos:

The Big 3
Horizontal Canal BPPV
Dix Hallpike
Epley

Authors:

– Dave McCreary
– Andy Neill

Clinical Question:

Can you bag a patient during apnoea in RSI?

Title of Paper:

Bag-Mask Ventilation during Tracheal Intubation of Critically Ill Adults

PMID [30779528]

Journal and Year:

NEJM. Feb 2019.

Lead Author:

Jonathan Casey

Background:

• Humans have a bit of an oxygen habit, sick humans in particular
• 40% of ICU intubations are complicated by hypoxaemia
• During traditional RSI we give patients an apnoea period, sick humans may not appreciate this
• The fear of helping out with some BVM ventilation is that the pressure might be > the gastro-oesophageal sphincter, insufflating gas into stomach and increase risk of aspiration
  But does it?

Study Design:

• Multicentre, parallel-group, unblinded, randomised trial in seven ICUs in the USA

Patients Studied:

• dult patients being intubated in ICU
• Excluded:
• Patients needing ETT so imminently that randomisation couldn’t occur
• Patients the treating clinician determined needed ventilation during apnoea (hypoxaemia or severe acidaemia) or where it was contraindicated (ongoing emesis, haematemesis, haemotysis).
  Intervention:
• Bag-Mask ventilation during interval from induction to laryngoscopy
• 10 breaths/minute
• Minimum volume needed to achieve chest rise

Comparison:

• Standard RSI – no ventilation permitted between induction and laryngoscopy. Except:
• After failed first attempt
• To treat hypoxaemia (Sats <90%)
• ny point the treating clinician thought it necessary

Outcomes:

• Primary: lowest O2 saturation during induction-laryngoscopy interval
• Secondary: incidence of severe hypoxaemia (Sats <80%)
• Safety outcome: clinical manifestation of aspiration – O2 sats, FiO2 & PEEP over first 24 hours post intubation with worst value between 6-24hours considered main safety outcome.
• Others: Operator reported orohapryngeal or gastric aspiration & presents of new opacity on CxR within 48 hours

Summary of Results:

• 401 patients enrolled – 199 BVM vs 202 Standard
• Median 60 years old
• 50% sepsis or septic shock
•  60% hyperaemic respiratory failure as indication for ETT
• 77% of the non-ventilation group got apnoic O2
• More of the BVM group had BVM as a pre-oxygenation method (39.7 vs 10.9%)

 

• Primary: lowest recorded sats during apnoic period
• BVM group: median sats 96% [IQR 87-99]
• Standard group: median sats 93% [IQR 81-99%]
• Difference in lowest sats: 4.7% [95%CI 2.5-6.8%]
• Difference greater for patients with lower initial sats

 

• Secondary: incidence of severe hypoxaemia
• BVM group: 21 patients (10.9%)
• Standard group: 45 patients (22.8%)
• RR 0.48 [95%CI 0.3-0.77]
• NNT 9 to prevent 1 incidence of severe hypoxaemia

Additionals:

• Less patients in the BVM group had sats <90% (29.5 vs 40.1%; RR 0.74; 95%CI 0.56-0.97)
• Less patients in the BVM group had sats <70% (4.1% vs 10.2%; RR 0.41; 95%CI 0.18-0.90)
• Median drop in sats 1% [IQR 0-7] in BVM group vs 5% [IQR 0-14] in standard group
• Aspiration risk:
• Operator reported – no difference
• New opacity on CxR within 48 hours – no difference
• O2 sats/PEEP/FiO2 requirements 6-24 hours – no difference

Authors Conclusion:

Among critically ill adults undergoing tracheal intubation, patients receiving bag-mask ventilation had higher oxygen saturations and a lower incidence of severe hypoxaemia than those receiving no ventilation.

Clinical Bottom Line:

I think this definitely supports that if your clinical opinion is that ventilation is needed and the patient isn’t high risk for aspiration then go ahead…using a really good, two-person technique and minimal volume needed for chest rise.

This is an ICU trial so the patients are going to be a little different to those we see in the ED needed an RSI. ICU patients are far more likely to have been fasted for longer than an ED patient and this study doesn’t report the NBM status of its participants. They mention in the excluded patients (you have to properly geek out and download the supplement to see it) that 3 patients were considered contraindicated because they had a ‘full stomach’. In contrast to that I would suggest that the majority of the septic, hypoxic respiratory failure patients that we are planning to RSI are unlikely to have had a Big-Mac and fries right before calling the ambulance.

Interestingly I don’t think I saw mention of cricoid pressure anywhere…actually its mentioned in the supplement – as “rarely” used at any participating centre. Nice.

Other #FOAMed Resources / References:

1. St. Emlyn’s have Journal Clubbed this paper
2. Our old pal Simon Laing & Rob Fenwick at the ResusRoom covered the paper on their March 2019 Podcast
3. Just for a change, Josh Farkas @Pulmcrit has a great summary on his blogs

Bag-Mask Ventilation during Tracheal Intubation of Critically Ill Adults

NG Tube reference

EMDOCS.net

This was recorded with around 15 serious PoCUS geeks in a hotel reception in Dublin following the ultrasound workshop at the Irish Association for Emergency Medicine annual conference.

A longer recording covering a number of papers will be published by our buddies over at UltrasoundGEL podcast. 

The paper discussed is this one

You can find more details on the ESP block below
www.youtube.com
www.asra.com