Transatlantic Intensive Care

When it comes to comparing patient outcomes in sepsis, we antipodeans often smugly sit back and comment that  “we don’t need no surviving sepsis campaign” (apologies to Pink Floyd) because our outcomes are compatible with, or better than those seen in the experimental arm of Rivers’ Early Goal Directed Therapy (EGDT) campaign.  The survival rate in the EGDT study was 30.5%, compared with 35.3% in the comparator arm of the severe sepsis subgroup of the SAFE study and, more recently, 23.7% in the comparator arm of the sepsis subgroup of the CHEST study.

My personal smugness continued when I read the title of this early release article by Mitchell Levy et al from Lancet Infectious Diseases a few days ago; “Outcomes of the Surviving Sepsis Campaign in intensive care units in the USA and Europe: a prospective cohort study.”  So you can imagine my surprise when I got to the punchline and found out that the (unadjusted) hospital mortality (a secondary outcome of the study) was 41.1% in the European group 28.3% in the US group.  Surely not?  Maybe the sample size was too small.  Nope, 25,375 patients.  That’s pretty impressive.  So what on earth was going on?  Are European intensivists so busy rioting and watching Eurovision that they’re neglecting their patients?  Let’s have a look.

The study was a large retrospective analysis of the surviving sepsis database across 107 ICUs in The USA and Europe.  As mentioned, 25,375 patients with severe sepsis or septic shock were included, 74% from the US and 26% from Europe.  The primary outcome was compliance with surviving sepsis guidelines in the first 6 hours and the first 24 hours.  Secondary outcomes included hospital mortality and ICU length of stay.  Interesting differences between the cohorts included the fact that 65% of US patients came to ICU via the ED, compared with only 32% of Europeans.  Therefore 51% of European patients came to ICU via the ward, compared with only 25% of Americans.  Regardless of origin, European patients had a longer hospital stay before arriving in the ICU (3.4 compared with 1.5 days for ward).  This difference in patient origin has no doubt contributed to the difference seen in outcome data.  Although no cause is apparent from the data, it seems appropriate to hypothesize that the lower number of ICU beds per capita in Europe (in general, with exceptions such as Germany and Belgium) means that patients who would go directly to ICU in the US end up going to the ward until they get sicker, making ICU admission more likely.

As a result of this, the European patients were a sicker group, with a higher SOFA score, a higher incidence of nosocomial sepsis, a longer ICU stay and a higher incidence of mechanical ventilation.  This of course explains the higher unadjusted mortality.  The US patients seemed to be a less sick cohort, with a much higher incidence of single organ dysfunction, particularly urosepsis, for example.  Despite the striking difference in unadjusted mortality (OR 1.8) mentioned in the preamble, once the mortality is adjusted for severity this difference disappears (OR 1.05 but no longer significant).  So it appears that the quality of intensive care is no different on either side of the Atlantic.  What does appear to be different is that the inevitable triaging that must occur when ICU beds are in short supply seems to have an impact on mortality.

So where does this leave us.  Particularly down under?  I think it highlights the fact that sick patients need to be looked after in ICU, and shouldn’t have to wait for the privilege.   I’ll be filing this study under politics rather than clinical medicine.  I think it helps to show that, despite being an expensive resource, intensive care saves lives and it can’t be carried out ad-hoc by overworked doctors and nurses on medical wards.  Critically ill patients with sepsis need to be in an ICU being looked after by intensivists and intensive care nurses.  I suspect that a cost analysis of the cost of ICU care for the patients who died versus the cost society of them dying will show quite a saving.

Here’s the study if you want to have a look for yourself;

Outcomes of the Surviving Sepsis Campaign in intensive care units in the USA and Europe: a prospective cohort study

Prof Mitchell M Levy MD,Prof Antonio Artigas MD,Gary S Phillips MAS,Andrew Rhodes MBBS,Richard Beale MBBS,Tiffany Osborn MD,Prof Jean-Louis Vincent MD,Sean Townsend MD,Prof Stanley Lemeshow PhD,Prof R Phillip Dellinger MD

The Lancet Infectious Diseases – 26 October 2012

DOI: 10.1016/S1473-3099(12)70239-6

ANZICS ASM 2012 Adelaide Day 1

I’ve spent the last few days in Adelaide, SA at the Australia and New Zealand Intensive Care Society (ANZICS) annual scientific meeting.  ANZICS is known throughout the acute medicine community worldwide for their amazing mutli-centre clinical trials that enrol thousands of patients (SAFE, NICE-SUGAR, CHEST) and this is their annual meeting and a highly regarded ICU conference.

Day one kicked off with Prof. Warwick Anderson, CEO of the Australian National Health and Medical Research Council (NHMRC) talking about the gap between basic science and bedside clinical medicine and highlighting new initiatives from NHMRC to help translate new research into clinical practice.  It is widely accepted that it can years or even decades for research to filter down to the front lines of medicine, so hopefully the NHMRC can help to combat this.

Next was Prof. Gordon Rubenfeld from Sunnybrook in Toronto on the global burden of critical illness.  Prof. Rubenfeld highlighted some of the issues associated with carrying out epidemiological studies in critically ill patients.  By way of example he commented on a ten fold difference in incidence of ARDS that has been noted between different medical systems.  Of course this does not mean that the actual number of cases of ARDS is different, but that in order to be diagnosed with ARDS, you have to be in an ICU.  In the developing world this can be a bit of a rarity.  He then went on to discuss the provision of critical care in the developing world, and stated that we need to develop “simple, robust, inexpensive technology” citing the example of the BIll and Melinda Gates foundation as a charitable trust that strives to improve the plight of those in the developing world and suggesting that in addition to clean water they should be providing cheap ventilators.

He gave an interesting analogy to ventilation in ARDS, stating that we should be recruiting care in the developing world while avoiding overdistention of care in the developed world.  We were grounded, however, with the fact that while apparently unnecesary care in the ICU costs ~$40,000,000 dollars per year, unnecessary imaging costs $33 billion!

Next was Prof. Christina Jones from Liverpool in the UK.  Prof. Jones is a nurse consultant who has done a PhD in post-ICU rehabiliation.  She spoke on the various physical and psychological scars that can remain in ICU survivors.  In addition to physical rehabilitation programmes, she spoke about ICU diaries as a method of decreasing the incidence of PTSD in survivors.

Next Prof. Randal Curtis from Harborview in Seattle spoke about advanced care planning in ICU.  Prof. Curtis is an intensivist with an interested in palliative and end of life care.  He spoke on the well known phenomenon of elderly, co-morbid patients spending their last days in ICU receiving aggressive treatment with curative intent rather than receiving aggressive palliative care.  He spoke on research carried out by his group and others on end of life communication with critically ill patients and their families. Some of the sobering statistics that he gave included the 1 in 5 deaths in the USA occur in ICU, but that if clinicians get involves in early discussions with family and patients, ICU admissions are decreased and family satisfaction with dying process increases (a so-called “good death”).

He went on to discuss techniques for conducting ICU family meetings, citing research carried out by his group showing that families only talk 29% of the time in meetings, and that family satisfaction was increased if they said more in the meeting.  He spoke on the balance between paternalism and autonomy in decision making process and factors such as prognostic and diagnostic certainty that may affect this balance.

The final talk of day 1 was from Prof. Geoff Chase, an engineer from Canterbury University in NZ.  He works with ICUs to provide engineering solutions to clinical problems, with research interests including closed loop systems for glucose management and breath to breath analysis of lung compliance in ventilated patients.  Interesting stuff and perhaps a glimpse into the future?

Stay tuned for day 2.

You can’t use ETCO2 to confirm tube placement in cardiac arrest – MYTH BUSTED!

Thinks to twitter buddies @keeweedoc and @paramedickiwi for inspiring me to write this.

Cardiac arrest is one of the more common indications for endotracheal intubation, indeed for many health professionals, like paramedics in jurisdictions without prehospital RSI, it may be essentially the only indication.  Over the last few years, the use of continuous, or waveform end-tidal CO2 monitoring has pretty much become ubiquitous, both inside the hospital and out. I think you would struggle to find an ambulance in a first world country that doesn’t have a defibrillator capable of waveform ETCO2.

ETCO2 is now considered a standard of care both for confirming correct ET tube placement, and for guiding ventilation to appropriate ETCO2 targets once intubated.  But there is still some doubt amongst practitioners as to the utility of ETCO2 in confirming tracheal intubation in cardiac arrest.

I was taught many years ago by an intensivist (who I have a great deal of respect for, I must add) that there is no role for ETCO2 in confirming tube placement in cardiac arrest.  Yes, ETCO2 can be used once the tube is in to assess the adequacy of chest compressions and to prognosticate, but the ETCO2 will be too low for it to reliably tell you if you have but the tube in the right hole.  The theory is that in a low cardiac output state, so little CO2 will be delivered to the lungs that you will get lots of false negatives and pull out tubes that were in the trachea to begin with.  Other (unreliable) methods of tube confirmation are advocated,  like auscultation and (o)esophageal intubation detectors (EIDs, eerily similar to IEDs, which you shouldn’t use to confirm intubation).

Over the last couple of years though, the teaching has changed.  Large-ish studies have shown that in fact ETCO2 can be used to confirm tube placement in cardiac arrest and of course NAP4 has shown that not using ETCO2 can lead to disastrous outcomes.  This has changed my practice and even led me to demand change in a hospital that I worked in and get a defibrillator capable of ETCO2 measurement brought to every cardiac arrest.    But the myth is still out there.  I’ve attached a reference to a letter in Anaesthesia from last year (I’m very much a believer in level 5 evidence) which, I think, will render the myth well and truly busted after reading. Its by arguably 2 of the biggest names in anaesthesia and ICU, Tim Cook and Jerry Nolan.  It’s superbly written, with quotes like;

“When intubation is undertaken within 30 min of cardiac arrest, failure to detect exhaled CO2 using wave- form capnography during CPR indicates that oesophageal intubation is very likely. ”

“In the better of the two studies supporting the use of capnography in cardiac arrest, there was 100% sensitivity and 100% specificity in identifying correct tracheal tube placement among 246 cardiac arrest patients (including four oesophageal tube placements) ”

“In the setting of CPR, all caregivers should assume a flat capnograph is due to a misplaced or blocked tube.  The message is simple: do not assume that failure to detect CO2 is because of cardiac arrest. ”

I couldn’t have put it better myself.

Cook, T. M. and Nolan, J. P. (2011), Use of capnography to confirm correct tracheal intubation during cardiac arrest. Anaesthesia, 66: 1183–1184. doi: 10.1111/j.1365-2044.2011.06964.x

Tension what?

Tension pneumothorax is a not-uncommon and much feared complication of major trauma.  Anyone who looks after trauma patients in the course of their clinical practice must consider the possibility of a tension pneumothorax in all patients with shock or respiratory distress and actively seek to rule it out or treat it.

I’d hope that we all think of tension pneumothorax in these situations, and given the increasing ubiquity of ultrasound as an extension of clinical examination it is becoming easier to rule it out.

Recently I saw a condition that, to be honest, I had previously doubted the existence of. A tension haemothorax.  Presented just like its airy cousin, but with blood instead of air.  Near instant improvement in circulation and ventilation once drained.

There isn’t much written about tension haemothorax, just case reports really.  So it’s pretty rare.  But it was a lesson for me that you always need to consider a secondary cause of shock, particularly an obstructive cause in a patient who’s response to treatment isn’t going as expected.  So I just wanted to write a short post telling everyone that tension haemothorax really exists.

Is it the destination or the journey?

I want to discuss 3 slightly related studies today.  All are early release article from Critical Care, but that’s not all they have in common.  They all have to do with location.  Any good real-estate agent will tell you that it’s all about location, and it would appear it’s the same for intensive care too.  Where you go, and how you get there, appear to make a difference.  While this shouldn’t come as much of a surprise, it’s a politically tricky issue.

The first study is a large retrospective case-control registry study from England and Wales.  They looked a patients who were transferred from one ICU to another for “non-clinical” reasons (i.e. not for neurosurgery or liver transplant or some other regional specialist service) or  within 48 hours of admission to ICU.  The reasons for transfer weren’t available from the registry data, but one would have to presume that lack of beds or staff was high up the list.

The authors identified 308,323 patients admitted to 198 ICUs between January 2008 and September 2011.  About 4000 patients were excluded for various reasons, and 759 were identified  as having been transferred within 48 hours for non-clinical reasons.  Each of these was then matched with 2 controls.

While unable to identify an effect of transfer on mortality, the authors noted a statistically significant increase in ICU stay of 3.2 days (95%CI 2.1-4.3, p<0.001) in those who were transferred for non-clinical reasons.

How odd.  Surely a trip down the road in an ambulance can’t add 3 days to your ICU stay?  Did they not have transport ventilators?  Was the poor SHO doing mouth-to-tube resuscitation the whole way?  The authors postulate that “physiological upset from transport” or something to that effect could have had an effect.  But 3 days?  Odd.  I work in a region that transfers patients between ICUs very frequently, so I’d be interested to see if the results were transferrable, and whether an organised, well trained retrieval medicine service would make a difference.

The next 2 studies are from continental Europe.  First from Germany where the authors again used registry data to look at the outcome of out-of-hospital-cardiac-arrest (OOHCA) patients based on what hospital they got taken to.  Specifically whether they were taken to a centre capable of percutaneous coronary intervention (PCI) or not.  Now in Germany critically ill patients are looked after by doctor-paramedic teams prehospital, so the doctors were able to use their clinical judgement to decide where to take the patient.  There were no protocols, as there are for trauma and stroke, for example.

The authors identified 889 patients who had a cardiac arrest in Dortmund (city population 580,000; but metro population 5.2 million) in 2008.  Children and patients with traumatic cardiac arrest were excluded, as were those with incomplete data.  The numbers all seem pretty standard; 63% male, median age 69, 26% in VF or VT, 52% witnessed, 82% at home, 13% bystander CPR, 40% ROSC, 10.9% survival to hospital discharge (I had to calculate that myself, always makes me suspicious.)  The outcome they were interested in was the effect of destination hospital on survival to discharge and neurological status at one year.

They found that patients taken directly to a PCI centre were younger, more likely to have a presumed cardiac aetiology, more likely to have ROSC in the field and more likely to have had a GCS of 15 before collapsing.  Once they got the PCI centre, patients were more likely to get a PCI (obviously – but only 50% did) but also more likely to get an echo within 2 hours of arrival and to get therapeutic hypothermia.  They were had a longer ICU stay, more days of mechanical ventilation and were more likely to have an ICD inserted.

The odds ratio for survival to discharge for those taken to PCI centre was 4.5 (!) (40% vs 16% discharged alive).  There was a similar difference in 1 year survival but  no significant difference in neurological outcome.

This sounds pretty amazing.  Even if you don’t get a PCI you do better if taken to a PCI capable hospital after your OOHCA.  But actually, what I think this study shows is exactly the opposite – you get taken to a PCI centre if you’re more likely to survive.  Patients taken to the PCI centres were younger, had likely cardiac aetiology for their arrests, got ROSC prehospital and were less likely to be disabled premorbidly.  There was a big selection bias here.  The young guys who got ROSC after one shock went to the PCI centre sitting up in the back of the ambulance chatting about how lucky they were, while the 90 year olds from the nursing home went to the community hospital in asystole with CPR in progress.  Actually, thats a bit mean.  I have just said that more of the patients in the PCI centre group were ventilated in ICU for longer.  I’m just not sure that this study says anything earth shattering, however I”m happy to be proved wrong if someone thinks I’ve misread it.

I do think it was an interesting and well thought out study though.  It would have been nice to have a bit more data on the patients, like how many of those taken to the non-PCI centre died in the ED (i.e. were dead when they arrived).  But what this study does say to me is that EMS providers (be they docs or paramedics) should be able to take a patient to the hospital that they believe is best, not the closest one.  In a large city with lots of hospitals, it just makes sense for the most critically ill patients to be taken to large tertiary centres with large ICUs staffed by specialist intensivists, senior trainees and very experienced nurses.  We’ve known this for a long time for trauma, and it amazes me that it’s taking so long for us to catch up with cardiac arrest, which is far more common.

Finally, a study (again retrospective) from France looking at the effect of the mode of transport, rather than the destination, on mortality.    Now this one was pretty interesting. They looked at 1,958 patients admitted to French university hospital ICUs with severe trauma (ISS >15) over a 3 year period.  They compared mortality at 30 days or hospital discharge between those brought to hospital by ambulance and those brought in by helicopter.  Now in France the crewing of both modalities is the same (doctor/nurse/driver or pilot) so you’d expect there to be no difference in the care received.  And you’d be wrong.

Looking at the data first.  74% were transported by road, 24% by helicopter.  Mean ISS was the same (25) but there was more hypotension (SBP <90) in the helicopter group.  Prehospital time was significantly longer in the helicopter group (surprise, surprise) at 2.3 vs 1.8 hours.  Yes, you read that right, around 2 hours in both groups.  And here was I thinking that 20 minutes on scene with a trauma patient was a long time.  It isn’t clear what effect entrapment had on these times.  Oh, and the helicopter group had more procedures prehospital (intubation, chest decompression, transfusion).  Although crude mortality was the same between the 2 groups, An adjusted analysis (for male gender, time of day, seriousness of accident) showed a decreased risk of death in the helicopter group (0.68, p=0.035)

So despite spending longer playing with their toys in the field, the helicopter crews were able to improve survival.   But how? The authors of the study don’t know, but postulate that the helicopters tend to be crewed by doctors and nurses from larger, regional hospitals whereas the road ambulances tend to be crewed by docs and nurses from smaller community hospitals.  So it may be the experience and decision making ability of the more experienced helicopter crews that makes the difference.  Food for thought anyway.